ATT 2 - Sargent Ranch Quarry Draft EIR — Mountain View City Council, April 25, 2023 (part 3 of 4)

Impacts associated with expansive soils, lateral spreading, subsidence, and soil collapse are not included in this analysis. Refer to Section 3.7.4.2, Significance Criteria, below, and to Section 3.1, Introduction to Environmental Analysis for additional information. Impacts to groundwater resources are not evaluated in this section, but rather are analyzed in Section 3.10, Hydrology and Water Quality.

3.7.2 Regulatory Setting

3.7.2.1 Federal
Mine Safety and Health Administration
The Mine Safety and Health Administration (MSHA), a division of the U.S. Department of Labor, administers the provisions of the Federal Mine Safety and Health Act of 1977. MSHA develops and enforces mandatory safety and health regulations pursuant to the Code of Federal Regulations (CFR) that apply to all surface and underground mines located in the U.S. through inspections, rigorous training, and providing educational programs for employers and employees in the mining industry. The ultimate purpose is to eliminate fatal accidents, reduce the frequency and severity of nonfatal accidents, minimize health hazards, and promote improved safety and health conditions in mines of the United States. Project operation would be regulated by MSHA, and periodic inspections would be performed under MSHA regulations to ensure maximum worker safety. Mining operations are subject to periodic safety inspections by MSHA.

3.7.2.2 State
Surface Mining and Reclamation Act
The Surface Mining and Reclamation Act (SMARA) and its implementing regulations (14 Cal. Code Regs. Section 3500 et seq.) address geotechnical slope stability for both fill slopes and cut slopes. SMARA does not specify a minimum Factors of Safety (FOS) required for slope stability. However, Section 3704(f) of the regulations requires that: “Cut slopes, including final

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-2 ESA / D201901577.01
Draft EIR July 2022
highwalls and quarry faces, shall have a minimum slope stability FOS that is suitable for the proposed end use and conform with the surrounding topography and/or approved end use.” For fill slopes, Section 3704(d) states that “fill slopes shall be 2:1 Horizontal to Vertical (H:V) or flatter. Slopes steeper than 2:1 H:V must be supported by site specific geologic and engineering analyses to indicate that the minimum FOS is suitable for the proposed end use.” More generally, Section 3704(e) states that at closure, all fill slopes, including permanent piles or dumps of mine waste and overburden, shall conform with the surrounding topography and/or approved end use.

For the Project, the proposed end use is cattle grazing.

Alquist-Priolo Fault Zoning Act
The Alquist-Priolo Earthquake Fault Zoning Act (Alquist-Priolo Act) (Public Resources Code Section 2621 et seq.) addresses the hazards posed by surface faulting to structures for human occupancy. The primary purpose of the Alquist-Priolo Act is to prevent the construction of buildings intended for human occupancy on the surface traces of active faults. The Alquist-Priolo Act also is intended to provide the citizens with increased safety and to minimize the loss of life during and immediately following earthquakes by facilitating seismic retrofitting to strengthen buildings against ground shaking.

The Alquist-Priolo Act requires the State Geologist to establish and regularly review and update regulatory “earthquake fault zones” around the surface traces of active faults and to issue appropriate maps sufficiently defining potential surface rupture or fault creep to assist cities and counties in planning, zoning, and building regulation functions. Local agencies must enforce the AlquistPriolo Act in the development permit process, where applicable, and may enact regulations that are more restrictive than State law requirements. Projects within an earthquake fault zone can be permitted, but only after cities and counties have required a geologic investigation prepared by a licensed geologist to demonstrate that buildings will not be constructed across active faults. If an active fault is found, a structure for human occupancy cannot be placed over the trace of the fault and must be “set back.” Although setback distances may vary, a minimum 50-foot setback is generally required.

The Sargent Fault, which extends just north of Tar Creek along the north side of the Project site, is zoned within an Alquist-Priolo Act fault zone; however, no elements of the Project are within the required Alquist-Priolo fault zone setbacks. The smaller fault (discussed below and termed a “splay fault” in this section) that appears to be a splinter of the Sargent fault extending through the mid-portion of the Project site, is not zoned under the Alquist-Priolo Act but is considered a Geologic Hazard Zone (GHZ) by the County (see additional discussion in Section 3.7.3.1).

Seismic Hazards Mapping Act
The State of California passed the Seismic Hazards Mapping Act of 1990 (Public Resources Code Sections 2690–2699) to address the effects of strong ground shaking, liquefaction, landslides, and other ground failures due to seismic events. Under the Seismic Hazards Mapping Act, the State Geologist is required to delineate “seismic hazard zones.” Cities and counties must regulate certain development projects within these zones until the geologic and soil conditions of their project sites have been investigated and appropriate mitigation measures, if any, have been

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-3 ESA / D201901577.01
Draft EIR July 2022
incorporated into development plans. Under Public Resources Code Section 2697, cities and counties must require, prior to the approval of a project located in a seismic hazard zone, submission of a Preliminary Geotechnical Report defining and delineating any seismic hazard.

Each city or county must submit one copy of each Preliminary Geotechnical Report, including mitigation measures, to the State Geologist within 30 days of its approval.

State publications supporting the requirements of the Seismic Hazards Mapping Act include the CGS SP 117A, Guidelines for Evaluating and Mitigating Seismic Hazards in California, discussed above, and SP 118, Recommended Criteria for Delineating Seismic Hazard Zones in California (2004). SP 117A provides guidelines to assist in the evaluation and mitigation of earthquake-related hazards for projects within designated zones requiring investigations and to promote uniform and effective Statewide implementation of the evaluation and mitigation elements of the Seismic Hazards Mapping Act. SP 118 provides recommendations to assist the CGS in carrying out the requirements of the Seismic Hazards Mapping Act to produce the Probabilistic Seismic Hazard Maps for the State. If and when the CGS evaluates the 7.5-minute geologic quadrangle containing the Project site (Chittenden Quadrangle) under the Seismic Hazard Mapping Act, the Project site and surrounding areas would be designated a landslide hazard zone based on the large number of existing landslides.

California Building Code
The California Building Code (CBC), Title 24 of the California Code of Regulations, Part 2, was promulgated to safeguard the public health, safety, and general welfare by establishing minimum standards related to structural strength, means of egress facilities, and general stability of buildings. The purpose of the CBC is to regulate and control the design, construction, quality of materials, use/occupancy, location, and maintenance of all buildings and structures within its jurisdiction. The provisions of the CBC apply to the construction, alteration, movement, replacement, location, and demolition of every building or structure, or any appurtenances connected or attached to such buildings or structures throughout California (California Department of General Services [DGS] 2020).

The 2019 edition of the CBC took effect starting January 1, 2020. The 2019 CBC contains California amendments based on the American Society of Civil Engineers (ASCE) Minimum Design Standard ASCE/SEI 7-16, Minimum Design Loads for Buildings and Other Structures, provides requirements for general structural design and includes means for determining earthquake loads as well as other loads (such as wind loads) for inclusion into building codes.

Seismic design provisions of the building code generally prescribe minimum lateral forces applied statically to the structure, combined with the gravity forces of the dead and live loads of the structure, which the structure then must be designed to withstand. The prescribed lateral forces are generally smaller than the actual peak forces that would be associated with a major earthquake. Consequently, structures should be able to: (1) resist minor earthquakes without damage, (2) resist moderate earthquakes without structural damage but with some nonstructural damage, and (3) resist major earthquakes without collapse, but with some structural as well as nonstructural damage. Conformance to the current building code recommendations does not constitute a guarantee that substantial structural damage would not occur in the event of a

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-4 ESA / D201901577.01
Draft EIR July 2022
maximum magnitude earthquake. However, a structure designed in-accordance with the seismic requirements of the CBC should not collapse in a major earthquake (DGS 2020).

3.7.2.3 Local
Santa Clara Geologic Ordinance
The County’s policies and standards pertaining to geologic hazards and associated investigation and mitigation standards are contained in Title C, Division C12, Chapter IV of the County of Santa Clara Ordinance Code. The geologic ordinance establishes minimum requirements for the geologic evaluation of land based on proposed land uses. It further establishes procedures to enforce these requirements, including rules and regulations for the development of land which is on or adjacent to known potentially hazardous areas, or which has the potential to create or increase the risk of geologic hazard. The provisions of the ordinance are also intended to ensure that the County fulfills its duties under state law regarding geologic hazards, including the Alquist-Priolo Act (surface fault rupture) and the Seismic Hazards Mapping Act (earthquake-induced landslides and liquefaction ground failure). The County Planning Office and/or the County Geologist reviews land development applications, building permit applications and land use proposals using maps showing the official County GHZs, other maps and pertinent data, including, but not limited to previous investigations of the subject property, to determine if a geologic investigation is required.

In addition, the ordinance sets forth minimum standards for the investigation and remediation of hazardous geologic conditions and approval of geologic reports by the County Geologist.

While the Project site has not been evaluated by the CGS for landslides or liquefaction under the Seismic Hazard Mapping Act, nearly the entire Project site is zoned as a landslide GHZ and the mid-portion of the Project site is zoned as a fault rupture GHZ. As a result, the Project site must comply with reporting, enforcement, and mitigation requirements set forth by the County’s requirements for investigation and mitigation standards contained in Title C, Division C12, Chapter IV of the County of Santa Clara Ordinance Code.

County of Santa Clara Surface Mining and Reclamation Ordinance The County of Santa Clara Surface Mining and Reclamation Ordinance (Sections 2.10.040 and

4.10.370 of the County Zoning Ordinance) was adopted to comply with and implement the provisions of SMARA by adopting procedures for reviewing, approving, and/or permitting surface mining operation, reclamation plans, and financial assurances in the unincorporated areas of the county. The ordinance sets forth the general procedural, operational, and reclamation requirements that must be complied with, where applicable, by surface mining and production operations in the county. The Ordinance contains requirements for the content of a reclamation plan, the review procedure and mining standards.

The following lists applicable standards on setbacks and final slope gradients contained in the ordinance that would apply to the Project:
• Cut slope setbacks: Cut slopes shall be no closer than 25 feet distant from any adjoining property line, except where adjoining property is being mined; nor 50 feet to any right-of way of any public street, or official plan line or future width line of a public road.

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-5 ESA / D201901577.01
Draft EIR July 2022
• Ridgeline setbacks: When surface mining occurs in a canyon area which abuts an urban area or the ridgeline is visible from the valley floor, the top of the uppermost cut area shall be as shown in an approved reclamation plan, or in the absence of an approved plan, not less than 50 feet from the top of the ridge existing prior to excavation. • Final Slope Gradient: The designed steepness and proposed treatment of the mined lands’ final slopes shall take into consideration the physical properties of the slope material, landscaping requirements, and other factors. The maximum stable slope angle might range from 90 degrees in a sound limestone, igneous rock, or similar hard rock to less than 20 degrees in highly expansive clay. In all cases, reclamation plans shall specify slope angle flatter than the critical gradient for the type of material involved. – Dangerous contours shall be eliminated from the land surface of the excavated area. – Whenever final slopes approach the critical gradient for the type of material involved, regulatory agencies shall require an engineering analysis of the slope stability. Special emphasis on slope stability and design will be necessary when public safety or adjoining property may be affected.
– The Planning Commission, at the time of approval or modification of the plan, may, based on the maximum stable slope angle of the material involved, specify the slope of the reclaimed land surface, may require grading or back-filling, and may require the elimination of unnatural steps or benches where necessary to carry out the reclamation plan. • Erosion and Drainage: Grading and revegetation shall be designed to both prevent excessive erosion and to convey surface runoff to natural drainage courses or interior basins designed for water storage. Lakes, ponds, streams, or other bodies of water may be created within an excavation only when created in accordance with the reclamation plan approved by the Commission after considering the recommendations of the County Health Department, Santa Clara Valley Water District and other affected agencies. Final surfaces shall be treated to prevent erosion unless otherwise specifically permitted by the Planning Commission.

On-Site Wastewater Treatment Systems (Septic Systems) Ordinance Division B11, Chapter IV, of the County Ordinance Code establishes regulations for the approval, installation, and operation of on-site wastewater treatment systems (OWTS) within unincorporated Santa Clara County, consistent with the Central Coast Regional Water Quality Control Board (RWQCB) standards and water quality plans. Division B11, Chapter IV was adopted to prevent the creation of health hazards and nuisance conditions and to protect surface and groundwater quality. The accompanying Onsite Systems Manual to Division B11 provides policies, procedures, and technical details related to permitting, design, construction, and operation of on-site septic systems. Requirements for soil percolation, groundwater separation, ground slope, and setbacks are specified.

Prior to installation of an OWTS, a permit must be obtained from the County Department of Environmental Health (DEH). Permits will only be issued in areas of the County where a sanitary sewer is not available. OWTS cannot be used if soil conditions, topography, high groundwater, or other factors indicate this method of sewage disposal is unsuitable. OWTS are not allowed within 100 feet of a water well, 50 feet of a drainage swale, or on soils where a high-water table extends close to the land surface.

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-6 ESA / D201901577.01
Draft EIR July 2022
Section B11-60 of the County Ordinance Code applies to OWTS with design wastewater flows of up to 10,000 gallons per day (gpd). Additionally, an operating permit and regular inspections are required for OWTS treating flows greater than 2,500 gpd. Alternative septic systems of any size (necessary if certain setbacks cannot be maintained, such as separation to high seasonal groundwater or steep slopes) can also require the issuance of a renewable operating permit, depending on the nature of the alternative treatment methods (DEH 2018).

Section B11-86 of the County Ordinance Code addresses abandonment of OWTS and requisite DEH permitting. Abandoned OWTS must have their sewage removed and disposed of in a County-approved manner. The tank top and bottom must be crushed and backfilled.

Abandonment requires issuance of a septic tank abandonment permit from the DEH.

Santa Clara County General Plan
Section SC of the Safety and Noise Element of the Santa Clara County General Plan (County of Santa Clara, 1994) addresses natural hazards. This element includes several geology and seismic policies that pertain to this Project:

Policy R-HS 16: No new building site shall be approved on a hazardous fault trace, active landslide, or other geologic or seismic hazard area that poses a significant risk.

Policy R-HS 19: In areas of high potential for activation of landslides, there shall be no avoidable alteration of the land or hydrology which is likely to increase the hazard potential, including:
a. saturation due to drainage or septic systems;
b. removal of vegetative cover; and
c. steepening of slopes or undercutting the base of a slope.

Policy R-HS 21: Proposals involving potential geologic or seismic hazards shall be referred to the County Geologist for review and recommendations.

In addition, Part 5, South County Joint Area Plan contains the following policy regarding geologic hazards in the rural county:

Policy SC 15.1: Geotechnical investigations should be required on all projects in unstable areas, including areas of expansive soils, prior to construction to insure that the potential hazards are identified and can be properly mitigated. A contract should be negotiated:
with the State Department of Mines and Geology for completion of a study of the Santa Cruz Mountains from the southern county border to the New Almaden area (approximate cost: $l0,000 per year for 3 years), and between the Cities and a consulting geologist for the review of development projects in potentially hazardous areas would be covered by a fee to developers).

The County General Plan (1994) also recognizes paleontological sites as having scientific value and the potential to increase knowledge of the natural world and includes a goal (Goal 5.1) to protect and preserve paleontological resources. Policies C-RC 49 and R-RC 81 state that heritage resources, which include paleontological resources, within Santa Clara County and within rural unincorporated areas should be preserved. Policies C-RC 50 and R-RC 82 provide a Countywide

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-7 ESA / D201901577.01
Draft EIR July 2022
general approach to heritage resource protection, which involves: (1) Inventory and evaluation of heritage resources, (2) Prevention or minimization of adverse impacts on heritage resources, and (3) restoration, enhancement, and commemoration of resources as appropriate. Additional policies and recommendations set the guidance by which the general approach is to be implemented. The following policies are relevant to the evaluation of the paleontological resources impacts of the Project:

Policy R-RC 85: No heritage resource shall knowingly be allowed to be destroyed or lost through a discretionary action (zoning, subdivision site approval, grading permit, building permit, etc.) of the County of Santa Clara unless:
a. The site or resource has been reviewed by experts and the County Historic Heritage Commission and has been found to be of insignificant value; or b. There is an overriding public benefit from the project and compensating mitigation to offset the loss is made part of the project.

Policy R-RC 86: Projects in areas found to have heritage resources shall be conditioned and designed to avoid loss or degradation of the resources. Where conflict with the resource is unavoidable, mitigation measures that offset the impact may be imposed.

Policy R-RC 88: For projects receiving environmental assessment, expert opinions and field reconnaissance may be required if needed at the applicant’s expense to determine the presence, extent, and condition of suspected heritage resources and the likely impact of the project upon the resources.

Policy R-RC 92: The participation of concerned citizens and professionals dealing with heritage resources in the identification of sites and the review and conditioning of projects by its boards and commissions shall be encouraged by the County.

The Society for Vertebrate Paleontology (SVP) has established standard guidelines that outline acceptable professional practices in the conduct of paleontological resource assessments and surveys, monitoring and mitigation, data and fossil recovery, sampling procedures, and specimen preparation, identification, analysis, and curation. Most California State regulatory agencies, including the County, accept the SVP standard guidelines as a measure of professional practice.

3.7.3 Environmental Setting

3.7.3.1 Geology, Soils, and Seismicity
Regional Geologic Setting
The Project site is in the central Coast Ranges Geomorphic Province,1 which is characterized by northwest-trending 2,000- to 4,000-foot-high mountain ranges and intervening valleys. The ranges and valleys trend northwest, subparallel to the San Andreas Fault. The Coast Ranges are composed of thick Mesozoic and Cenozoic-aged (225 million years ago to present) sedimentary strata. The northern and southern ranges are separated by a depression containing the San 1 A geomorphic province is a region of unique topography and geology that is readily distinguished from other regions based on its landforms and diastrophic history (Paleo Solutions 2017).

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-8 ESA / D201901577.01
Draft EIR July 2022
Francisco Bay (CGS 2002). The Santa Cruz Mountains, which is a range within the province, extends from San Francisco to Hollister in the southern end of the Santa Clara Valley. The Project site is on the eastern slopes of the Sargent Hills situated in the low-lying foothills at the southern end of the Santa Cruz Mountains.

Project Site Topography and Geology
Topography
Project site topography consists of gently rolling to moderately steep hillsides with moderate to well-incised drainages. Relief at the Project site ranges from approximately 800 feet above mean sea level (msl) along the higher ridge crests to less than 150 feet msl along the eastern portions of site. Average overall slope angles are approximately 15 degrees in the proposed development areas. The site is bisected by the south-flowing Sargent Creek (SGS 2016).

Naming Conventions for Geologic Units
The Project site geology, specifically the rock types and their structure, has been the subject of several geologic investigations over the past several decades. Since 1958, six geologic maps have been produced for the area surrounding Sargent and all maps included the Project site. See Jennings and Strand 1958; Dibble and Brabb 1978; Graymer 1979; Wagner, Greene and Saucedo, and Pridmore 2002; and Dibblee Minch (ed.) 2006. The geologic interpretations and the maps that resulted from these investigations all differ slightly. This can be expected because as more information is obtained through each subsequent investigation, rock types and their origins are clarified and correlations between the units are refined.

The most obvious differences in the geologic maps produced during the five previous field investigations are the interpretations comprising the Etchegoin Formation. Previous investigations (Dibblee and Brabb 1978; Graymer 1979; Wagner et al. 2002) mapped the rocks in the north part of the Project site (south of Tar Creek) and those at the southern end (near mining Phases 3 and 4) as distinct units of non-marine sandstone and mapped the remainder of the Project site as marine sandstone (Etchegoin Formation). Works by Jennings and Strand (1958) and Dibblee and Minch (2006) identify the entire Project site as underlain by marine deposits; Dibblee and Minch (2006) refer to these units as belonging to the Etchegoin Formation. This distinction is important because the slope stability analysis completed by SGS (2016) described Project site geology using nomenclature put forth by Graymer (1979), while the paleontology study, prepared by PaleoSolutions, Inc. (2017), relied on the geology nomenclature used by the more recent Dibblee and Minch (2006) compilation. Therefore, the naming convention used by SGS to describe Project site marine deposits (Tscm) can be considered equivalent to the Etchegoin Formation (Te) applied in the paleontology study. The identifier for non-marine deposits (Tscn), used by SGS, is equivalent to the identifier for unnamed non-marine deposits (Tn) used by PaleoSolutions, Inc. In this geologic impact analysis, the identifiers (Tscm)/(Tscn) and (Te)/(Tn), respectively, are used interchangeably. The unit identifiers are different names for units with similar characteristics, so the differences do not affect the analysis of the Project’s impacts.

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-9 ESA / D201901577.01
Draft EIR July 2022
Site Geologic Conditions
As shown in Figure 3.7-1, most of the Project site is underlain by Pliocene-aged marine sandstone and claystone of the Etchegoin Formation (Te) with a smaller portion in the southern area underlain by an unnamed non-marine claystone (Tn) (Dibblee and Minch 2006). The sediments making up these rocks were deposited in shallow marine, marginal marine, and non‐ marine environments and contain inter‐bedded pebble and cobble conglomerates;2 coarse‐ to fine‐ grained sandstones, brown siltstone, and silty claystones (SGS 2016).3 Marine (Te) and nonmarine (Tn) deposits can be differentiated based on the presence of fossils. Marine fossils were observed west of Sargent Creek, predominantly along the upper benches/knobs (SGS 2016).

SGS conducted a subsurface investigation as part of its slope stability analysis, which included drilling soil borings and excavating test pits. The field investigation consisted of 11 soil borings advanced to depth between 47 and 100 feet and 43 test pits, each to a depth of about 7 feet. SGS identified marine and non-marine deposits as non-marine quartz sandstone (Tscn) and marine pebble and quartz conglomerate (Tscm). The non-marine deposits consist of fine to coarse sands, silts, and clay mixtures with some rounded gravels and cobbles up to 8 inches in diameter. These deposits were massive,4 cross bedded,5 and interbedded.6 Individual rocks (i.e., clasts) varied from granitic and coarse-grained, hard dark sandstone (graywacke), predominantly in the southern and central portions of the site. SGS also reported that the marine deposits (Tscm) were observed and mapped during its investigation but were not encountered in test pits or exploratory borings during the subsurface investigation. The Tscn and Tscm units are oriented (strike) toward the northeast with an incline (dip) of about 30 to 45 degrees to the southeast. (SGS 2016) The materials encountered during this subsurface investigation are consistent with the materials encountered during the exploratory drilling conducted by Graniterock Exploration Services in 2007, which advanced three deep soils borings to depths of 150, 250, and 360 feet. (SGS 2017) Alluvial7 deposits (Qpaf by Graymer 1997 and Qa by Dibblee and Minch 2006) are present at the Project site in the northern portion near Tar Creek, along Sargent Creek and its tributary drainages, and along the Pajaro River. These deposits comprise mixtures of cobbles, gravels, sand, silts, and clays and range from a few inches thick in the upper reaches of the watershed areas, where erosion has cut the channels, to multiple feet thick where the channels widen and deepen as they approach the flatter terrain of the Pajaro River Valley (SGS 2016). Older alluvium, denoted by Dibblee as Qoa, was mapped in limited areas in the southern extremities of the Project site.
2 A conglomerate is a sedimentary rock made up of many smaller rocks within a cemented matrix. 3 Marine depositional environments are those where deposition of sediments occur through water (e.g., shallow inland sea). Coastal deposition is an example of marginal marine and non-marine environments are those where sediments are deposited on land through landslides, erosion and sedimentation. 4 The term “massive” as a geological description of rock mechanics, refers to a durable rock or deposit that is said to be isotropic (same in all directions) homogeneous and is free of fissures, bedding, foliation or other discontinuities.

Strength does not vary appreciably from point to point (Jackson 1997). 5 Stratigraphic bedding that is inclined at an angle to the main plane (Ibid.) 6 Sedimentary beds lying between or alternating with others of different character (Ibid.). 7 Alluvial deposits are made up of eroded rock and soil materials that are deposited by water (fluvial processes).

Phase 2
Phase 1
Phase 4
Pit #4
Phase 3
SOURCE: Paleo Solutions, 2017
SFO/19xxxx/D191577.00 - SCC Sargent Quarry/05 Graphics-GIS-Modeling/Illustrator SCC Sargent Quarry
Figure 3.7-1
Project Geology Map

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-11 ESA / D201901577.01
Draft EIR July 2022
Surficial deposits at the Project site include topsoil/colluvium and landslide deposits. Landslide deposits are identified as Qls by Dibblee and Minch (2006). Unconsolidated topsoil/colluvial materials are located outside of the drainages along the slope faces and atop the ridges. In general, these deposits consist of brown, fine to coarse sand containing gravel and cobbles at an approximate thickness of 3 feet. Laboratory testing determined that the topsoil/colluvial materials exhibit weak shear strengths and could be unstable on steepened slopes (SGS 2016).

Soils
Nine soil-mapping units have been identified on the Project site. Each unit is described in greater detail in Table 3.7-1. None of the soils of the site are considered hydric8 soils, i.e., soils that under appropriate hydrological conditions may support wetlands. All the soil types are considered well-drained and moderately to highly erodible.

TABLE 3.7-1

SOIL TYPES AT PROJECT SITE
Soil Series and Types
Map Unit
Symbol
Parent
Material
Drainage
Class
Percent
Hydric
Composition
Zamora Series
Zamora clay loam, 2-9% slopes ZbC Alluvium Well-drained 0 Azule Series
Azule clay loam, 15-30% slopes, eroded AuE2 Alluvium Well-drained 0 Azule clay loam, 15-30% slopes AuE Alluvium Well-drained 0 Azule clay loam, 9-15% slopes, eroded AuD2 Alluvium Well drained 0 Azule clay loam, 30-75% slopes AuG Alluvium Well-drained 0 Los Osos Series
Los Osos clay loam, 15-30% slopes LoE
Residuum weathered
from sandstone
and shale
Well-drained 0
Los Osos clay loam, 30-50% slopes LoF
Residuum weathered
from sandstone
and shale
Well-drained 0
Los Osos clay loam, 50-75% slopes LoG
Residuum weathered
from sandstone
and shale
Well-drained 0
Diablo Series
Diablo clay, 9-15% slopes DaD Residuum weathered
from sandstone Well-drained 0
SOURCES: USDA NRCS 2020; Freeman Associates 2022.
8 Hydric soil is a soil that formed under conditions of saturation, flooding, or ponding long enough during the growing season to develop anaerobic conditions in the upper part.

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-12 ESA / D201901577.01
Draft EIR July 2022
Trace Metals
Rock and soil often contain naturally occurring trace metals that could become hazardous to human health. Exposure to these trace metals can occur through the inhalation of fugitive dust emitted during excavation and processing of minerals. These trace metals also could be released into the surface water and groundwater. Cadmium and selenium are two common hazardous metals that could be encountered during quarry operation. Cadmium concentrations are highest in shale formations and selenium concentrations are highest in Cretaceous Period marine limestone deposits. However, given the Pliocene age of the underlying geology at the Project site, and the abundance of Holocene age alluvium, colluvium, and landslide deposits, there is a low probability of either metal occurring in high concentrations (Freeman Associates 2022).

Slope Stability
Landslides are prevalent at the Project site and in the near-vicinity due to the character of the geologic materials and the seismic setting (see below). Most of the Project site is zoned by the County as a GHZ for landslides (see Section 3.7.2.2, above). Several surficial to moderately deep-seated (backscarps of up to 40 feet in height) landslides were mapped in multiple areas across the Project site, as shown in Figure 3 in Appendix G.1 to this Draft EIR (SGS 2016).

These landslides appear to be relatively recent and are identified based on geomorphic9 features such as eroded scarps and irregular topography. Most of the slides appear to be surficial translational10 and to originate at the contact with the topsoil/ colluvial units and the underlying tertiary deposits (Etchegoin Formation), adjacent to slopes of incised drainages. In a few areas, however, the existing landslides extend below the surficial deposits into the underlying bedrock.

Closer examination of the back scarps11 revealed that the slides appeared to originate along fault planes and fractures in the underlying deposits (SGS 2016). The possibility also exists that the failure planes may have occurred along the interbedded silts and clays which occur at depth throughout the site. Some of the deeper slides noted near the proposed Phases 1, 2, and 3 appear to follow the direction of bedding in these areas and are rotational12 in nature (SGS 2016).

The presence of landslides and conditions (slope gradient and underlying materials) that could lead to future landslides could affect the slope angles proposed for the quarry excavations. While the vast majorities of slides are shallow/surficial and would be removed during excavation, some basal13 surfaces were observed to be deep seated and may daylight onto cut-slope faces. In addition, landslide debris above top‐of‐slope cuts may be encountered and the slides re‐activated by the excavations proposed under the mining plan (SGS 2016). 9 Pertaining to landforms and features.
10 Translational slides are those that involve downslope displacement of rock or soil on a surface that is roughly parallel to the general ground surface (Jackson 1997).
11 A back scarp is the slope face behind the failed section of a landslide. 12 Rotational slides take place on a well-defined, curved shear surface (concave upward) producing a backward rotation in the displaced mass (Ibid.).
13 Basal refers to bedrock surfaces that form or belong to a bottom layer or base.

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-13 ESA / D201901577.01
Draft EIR July 2022
Seismic Setting
The Project site area is in a seismically active region, situated between the San Andreas fault approximately 2 miles to the south, and the Sargent fault, which runs through the northern portion of the site (Freeman Associates 2022). The Sargent Fault Zone extends through the northern portion of Project site just north of Tar Creek. The Sargent fault is considered a “right-lateral reverse-oblique fault,” which means that its movement is a combination of right lateral (horizontal) and vertical thrust with the southwest side moving upward. The Sargent fault is considered a Holocene fault, meaning that there is evidence to suggest that this fault has experienced displacement within the last 11,700 years (CGS 2010). The Sargent fault thrust system is associated with the San Andreas Fault Zone as it breaks off from the San Andreas south of Los Gatos, runs southeast through the Santa Cruz Mountains, crosses the Pajaro River floodplain, and extends near the northeastern front of the Lomerias Muertas and Flint Hills (Freeman Associates 2022). Recent geologic mapping (Graymer 1997, Dibblee and Minch 2006) identified a shorter and older (displacement within the last 1.6 million years) fault trace associated with the main trace of the Sargent fault south of Tar Creek extending through what would become the quarry pits of Phases 1 and 2 (Figure 3.7-2). This fault is henceforth referred to as the Sargent “splay” fault.14
The 684‐mile San Andreas Fault Zone is the principal element of the San Andreas fault system, a network of faults with predominantly right lateral strike-slip displacement that collectively accommodates most of the relative north-south motion between the North American and Pacific plates (Freeman Associates 2022). Near the Project site, the Santa Cruz Mountains section of the San Andreas fault extends from Black Mountain in the northern Santa Cruz Mountains and runs southeast to just south of San Juan Bautista. The San Andreas Fault Zone and has several instances of historic (last 200 years) displacement.

The Sargent and the San Andreas fault zones are both delineated as Alquist-Priolo Act Earthquake Hazards Zones. The County has delineated the traces of the Sargent fault on the Project site as a Santa Clara County Fault Rupture Hazard Zone. These faults have the potential for generating strong ground motions and surface rupture at the Project site (Freeman Associates 2022).

3.7.3.2 Paleontological Setting
Paleontological resources are the fossilized remains of plants and animals: vertebrates (animals with backbones, such as mammals, birds, and fish), invertebrates (animals without backbones, such as starfish, clams, and coral), and microscopic plants and animals (microfossils).

Paleontological resources can include mineralized body parts, body impressions, or footprints and burrows. They are valuable, non-renewable, scientific resources used to document the existence of extinct life forms and to reconstruct the environments in which they lived. 14 The term “splay” is used here to describe the fault lineation extending through the Phase 1 mining area. A splay is a minor fault branching off of a larger fault.
)$8/7583785(=21(6 ),*85(

)*+,

-
-
-
- #(-
-

-

-
- $- -

c» ©sc¦»
c» }u¤6»
-» 6¶»
)
%
» 6¶»
µ» »
/*» »
}c0l» »W<ZlT» [»+» 6¶» 6¤» 0l<» '!» 6¶» L\dc» 068» s0<» »» 0l<» »
,.» 6¶» 6¤» 0p»
» 6¶»Pdc»
}Y0B» c» ¯¤gB»
}Y0» » sZc» » »O»
}Y0B» » s«
3¨Bl»
~Y0B» » s<¤6»
~Y0B» » sc» ¯§»
}Y0B» » s}» » ¸» » MBB»
}Y0B» » s«
3¨Bl»
}Y0B» » }u¤6»
}Y0B» » sc» ¯¦»
}Y0B» » s}» » ¸» » MBB»
}Y0B» » s¬
3¨Bl»
}Y0B» » }u¤6»
}Y0»
» sc» ¯¦»
~Y0B»
» » » ¸s}» » NC»
}Y0B»
» s«
3¨Bl»
}Y0B»
» }u¤6»

%» 6¶»
"» 6¶»
/» 6¶»
%#» 6¶»

» 6¶»
» 6¶»
» 6¶»
a»
» 6¶»
» 6¶»
'!» 6¶»
a$» 6¶»
/%» 6¶»
&» 6¶»
» 6¶»

» 6¶»
/» 6¶»
QX» » s®=B» g{ <BZcH»`sl» 4¶»j» }Y0G

- -

-
-
- #(-
-

-!-
%-
"
(-
&!-
- - "(- -

-!-
"-

- -

-
#
(-
' &!-

» » QX»
» 0p» »R
j» :s» B6y

kT»
z|³>» 0
s}|
s}|
z|
Ko
s}t
6BBb»
UE0
f^?B»
L0¤c»»»
0c
1¤Z
}Z»
}Z» »
» »
(

» 0;

/» 0;

+» 06B
r» s«
3¨J»
0<<Zsl0c»A£51l7»
f^>B»w» º»q

)*+,

-
-
-
- #(-
-

» 6¶»
» 6¶»
» 6¶»
a»
» 6¶»
» 6¶»
'!» 6¶»
a$» 6¶»
/%» 6¶»
&» 6¶»
» 6¶»

» 6¶»
/» 6¶»
QX» » s®=B» g{ <BZcH»`sl» 4¶»j» }Y0G

- -

-
-
- #(-
-

-!-
%-
"
(-
&!-
- - "(- -

-!-
"-

- -

-
#
(-
' &!-

» » QX»
» 0p» »R
j» :s» B6y

kT»
z|³>» 0
s}|
s}|
z|
Ko
s}t
6BBb»
UE0
f^?B»
L0¤c»»»
0c
1¤Z
}Z»
}Z» »
» »
(

» 0;

/» 0;

+» 06B
r» s«
3¨J»
0<<Zsl0c»A£51l7» B
f^>B»w» º»q

kT» c_h»» c^nD»
z|» T0@» s0<»
³>» 0» Ys´»
s}|» ¡±»»» 40»
s}|» °0» c^nD» Ssg»v» ²ec»
z|» s6B» °0» ~x»
KoT» Vs¤l<» 6sls¤» 0l<» IBª»
s}t» Ts¤l<» 6sls¤» 0l<» IBª»
» s9B» 0B0»
6BBb»
UE0w»
f^?B» BgB<Z0w» c_i]» c^nF
L0¤c»»»¤}¤B»»»
:slB
0c
1¤Z}Zscs»»»B1L:
r
Spring Creek
(B Fig. 2.3-4)
(A Fig. 2.3-4)
(A Fig. 2.3-4)
0 200 400 800 600 1200 Feet
Figure 3.7-2
Fault Rupture Zones
SOURCE: County of Santa Clara, 2021. SCC Sargent Quarry SFO/19xxxx/D191577.00 - SCC Sargent Quarry/05 Graphics-GIS-Modeling/Illustrator Phase 2
Phase 1
Phase 4
Phase 3

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-15 ESA / D201901577.01
Draft EIR July 2022
Fossils can be used to determine the relative ages of the depositional layers in which they occur and of the geologic events that created those deposits. The age, abundance, and distribution of fossils depend on the geologic formation in which they occur and the topography of the area in which they are exposed. The geologic environments within which plants or animals became fossilized usually were quite different from the present environments in which the geologic formations exist.

One system commonly used to determine paleontological sensitivity is the Potential Fossil Yield Classification (PFYC) system developed by the Bureau of Land Management (BLM) (BLM 2016).

The PFYC system predicts sensitivity based on two facts of paleontology: occurrences of paleontological resources are closely tied to the geologic units that contain them, and the presence of fossils can be estimated based on the distribution of geologic units near the ground surface. The PFYC system classifies the potential to find paleontological resources in a specific geologic unit on a scale of one to five, with five being the highest potential. The PFYC system classifications are:
• 1 = Very Low Potential: Geologic units are not likely to contain recognizable paleontological resources. Units are igneous or metamorphic, excluding air-fall and reworked volcanic ash units. Units are Precambrian in age. Management concern is usually negligible, and impact mitigation is unnecessary except in rare or isolated circumstances. • 2 = Low Potential: Geologic units are not likely to contain paleontological resources. Field surveys have verified that significant paleontological resources are not present or are very rare. Units are generally younger than 10,000 years before present. Recent aeolian deposits.

Sediments exhibit significant physical and chemical changes (i.e., diagenetic alteration) that make fossil preservation unlikely. Management concern is generally low, and impact mitigation is usually unnecessary except in occasional or isolated circumstances. • 3 = Moderate Potential: Sedimentary geologic units where fossil content varies in significance, abundance, and predictable occurrence. Marine in origin with sporadic known occurrences of paleontological resources. Paleontological resources may occur intermittently, but these occurrences are widely scattered. The potential for authorized land use to impact a significant paleontological resource is known to be low to moderate. Management concerns are moderate. Management options could include record searches, pre-disturbance surveys, monitoring, mitigation, or avoidance. Opportunities may exist for hobby collecting. Surfacedisturbing activities may require sufficient assessment to determine whether significant paleontological resources occur in the area of a proposed action and whether the action could affect the paleontological resources.
• 4 = High Potential: Geologic units that are known to contain a high occurrence of paleontological resources. Significant paleontological resources have been documented but may vary in occurrence and predictability. Surface-disturbing activities may adversely affect paleontological resources. Rare or uncommon fossils, including nonvertebrate (such as soft body preservation) or unusual plant fossils, may be present. Illegal collecting activities may impact some areas. Management concern is moderate to high depending on the proposed action. A field survey by a qualified paleontologist is often needed to assess local conditions.

On-site monitoring or spot-checking may be necessary during land-disturbing activities.

Avoidance of known paleontological resources may be necessary. • 5 = Very High Potential: Highly fossiliferous geologic units that consistently and predictably produce significant paleontological resources. Significant paleontological resources have been documented and occur consistently. Paleontological resources are highly susceptible to adverse impacts from surface-disturbing activities. Unit is frequently the focus

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-16 ESA / D201901577.01
Draft EIR July 2022
of illegal collecting activities. Management concern is high to very high. A field survey by a qualified paleontologist almost always is needed and on-site monitoring may be necessary during land use activities. Avoidance or resource preservation through controlled access, designation of areas of avoidance, or special management designations should be considered. • U = Unknown Potential: Geologic units that cannot receive an informed PFYC assignment.

Geological units may exhibit features or preservational conditions that suggest significant paleontological resources could be present, but little information about the actual paleontological resources of the unit or area is unknown. Geologic units represented on a map are based on lithologic character or basis of origin but have not been studied in detail.

Scientific literature does not exist or does not reveal the nature of paleontological resources.

Reports of paleontological resources are anecdotal or have not been verified. Area or geologic unit is poorly or under-studied. Qualified professionals have not yet been able to assess the nature of the geologic unit. Until a provisional assignment is made, geologic units with unknown potential have medium to high management concerns. Field surveys are normally necessary, especially prior to authorizing a ground-disturbing activity.

As discussed above under the heading “Naming Conventions for Geologic Units,” the geologic units that were identified within the Project site and that are consistent with geologic mapping by Dibblee and Minch (2006) are classified according to the PFYC criteria, as shown in Figure 3.7-1.

The Pliocene Etchegoin Formation (Te) has a high paleontological potential (4), the unnamed Pliocene claystone (Tn) has an unknown potential (U), and Pleistocene-age Quaternary older alluvium (Qoa) (if encountered subsurface) has a moderate paleontological potential (3). Holoceneage alluvial deposits (Qa) are generally less than 10,000 years old and are considered to have a low paleontological potential (2). Fossils that are discovered in landslide deposits (Qls) will lack stratigraphic context, and so these units are also considered to have a low paleontological potential (2) (Appendix G.2)

3.7.4 Impact Evaluation

3.7.4.1 Approach to the Analysis
Evaluation of environmental impacts associated with geology, soils, seismicity, and paleontology was supported by the field effort and technical reports provided by SGS, Golder Associates, and PaleoSolutions. SGS completed the slope stability analysis (See SGS 2016 in Appendix G.1),15 which characterized the Project site geology, seismic setting, and slope stability conditions. Golder Associates reviewed the 2016 SGS Slope stability analysis and provided comment, which SGS responded to accordingly (see Golder Associates 2017a and 2017b, and SGS 2017 in Appendix G.1). The combination of SGS analysis and Golder’s technical peer review provided a good technical understanding of the geologic and seismic conditions and the potential for slope instability during the proposed mining program. PaleoSolutions prepared a comprehensive paleontological assessment of the Project site, which assessed the potential for impacts to paleontological resource (Appendix G.2). Representatives of the County and members of the County’s environmental consultant team who have the relevant professional credentials and 15 When the geotechnical analyses in Appendix G were prepared, the Project phasing was different, than currently proposed but the Project footprints are unchanged. In the geotechnical analyses, Phase 1 is current Phase 3, Phase 2 is current Phase 4, Phase 3 is current Phase 1 and Phase 4 is current Phase 2.

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-17 ESA / D201901577.01
Draft EIR July 2022
experience have independently reviewed all Applicant-provided studies and technical reports on behalf of the County (including those cited in this section) and have found them to follow applicable protocols and appropriate for use in the EIR.

3.7.4.2 Significance Criteria
Consistent with CEQA Guidelines Appendix G, a significant impact would occur if the Project would:
a) Directly or indirectly cause substantial adverse effects, including the risk of loss, injury, or death involving:
i. Rupture of a known earthquake fault, as delineated on the most recent Alquist-Priolo Earthquake Fault Zoning Map issued by the State Geologist for the area or based on other substantial evidence of a known fault;
ii. Strong seismic ground shaking;
iii. Seismic-related ground failure, including liquefaction; or iv. Landslides.
b) Result in substantial soil erosion or the loss of topsoil; c) Be located on a geologic unit or soil that is unstable, or that would become unstable as a result of the Project, and potentially result in on- or off-site landslide, lateral spreading, subsidence, liquefaction or collapse;
d) Be located on expansive soil, creating substantial direct or indirect risks to life or property; e) Have soils incapable of adequately supporting the use of septic tanks or alternative wastewater disposal systems where sewers are not available for the disposal of wastewater; or f) Directly or indirectly destroy a unique paleontological resource or site or unique geological feature.

Due to the nature of the Project, certain criteria, or portions of a particular criterion are not analyzed in this section for the reasons described below:
e) Be located on a geologic unit or soil that is unstable, or that would become unstable as a result of the Project, and potentially result in on- or off-site landslide, lateral spreading, subsidence, liquefaction, or collapse. Impacts associated with lateral spreading, subsidence, and soil collapse are not analyzed further in this section. Lateral spreading is the lateral or downslope displacement of a soil or rock mass triggered by liquefaction of underlying materials. As discussed in Impact 3.7-1, the areas with potentially liquefiable soils are located along the Pajaro River south of the Project boundary and southeast of the Project boundary between the Union Pacific Railroad tracks and Betabel Road. These areas are generally flat lying and if liquefaction did trigger lateral spreading, it would only occur as localized failures. These areas of liquefaction potential are not located near proposed mining pits, processing areas, or roadway improvements and would not impact the Project construction or Project operations.

Subsidence is the lowering or settlement of the ground surface due to a substantial decline in groundwater levels, extraction of oil, underground mining, or the presence of an underground

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-18 ESA / D201901577.01
Draft EIR July 2022
void or cave. These conditions do not exist at the Project site. While the Project proposes to extract groundwater, the volume that is proposed to be extracted would not cause a substantial decline in groundwater levels or increase the potential of surface subsidence in the basin (see Section 3.10.4.3 in Section 3.10, Hydrology and Water Quality).

Soil and rock units can collapse due to the removal of underlying support; for example, rock or soil collapse can occur in areas overlain by lava tubes, caves, limestone cavities, or old mine shafts. These conditions do not exist at the Project site, nor would they be created by the Project and thus soil collapse is not considered a potential impact. d) Be located on expansive soil, creating substantial direct or indirect risks to life or property.

Previous laboratory testing of Project site soils determined that they do not exhibit shrinkswell properties and thus are not expansive (see SGS 2016 in Appendix G.1). Further, geotechnical investigations that are required prior to construction would require removal and replacement of expansive soils if they were identified. No impact would occur with respect to expansive soils because the removal and replacement of soils with shrink-swell characteristics, if present, would preclude the location of Project infrastructure on such soils and thereby avoid related impacts to life or property. Therefore, the Project could not contribute to an impact with respect to expansive soils.

3.7.4.3 Project Impacts
Impact 3.7-1: Seismic hazards could cause adverse effects including the risk of loss, injury, or death during a seismic event. (Less than Significant) This impact discussion corresponds to Significance Criteria (a(i)), (a(ii)), and (a(iii)) (see Section 3.7.4.2, above) and addresses the primary seismic hazards of fault rupture, seismic ground shaking, and liquefaction. As indicated, this impact analysis considers the indirect and direct impacts of the Project during construction and operation, including for the mining pits, processing plant, conveyor belts, rail spur, access road, roadway improvements, and reclamation.

Fault Rupture
The Project site borders the Sargent Fault Alquist-Priolo Earthquake Fault Hazard Zone to the north. While the Project site does not overlie the zoned portion of this fault zone, a potentially active branch or “splay” fault trace within the Sargent fault zone has been identified in the central portion of the Project site (Phase 1 and 2 area) and is considered a County Fault Rupture Zone.

Considering its relatively short length, history of past activity (1.6 million years ago to 700,000 years ago), and that it occurs as a branch fault off the main trace of the Sargent Fault, the splay fault would not be a source of earthquakes large enough to produce substantial ground rupture. Any damage resulting from an earthquake along the splay fault would be minor (Bryant and Hart 2007).

Construction
Phase 1 and 2 Conveyor Belt, Processing Plant, Tar Creek Bridge, and Rail Spur Fault rupture would not adversely affect construction of the processing plant, Tar Creek Bridge, rail spur, or Phase 1 and 2 conveyor belt because these Project components do not cross the trace of the Sargent splay fault.

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-19 ESA / D201901577.01
Draft EIR July 2022
Phase 3 and 4 Conveyor Belt and Road Improvements
Fault rupture would not adversely affect Phase 3 and 4 site construction, conveyor belt installation, and road improvements because these project components do not cross the trace of the Sargent splay fault. The probability of an earthquake occurring during the 9-month construction period is far lower than the probability of an earthquake occurring over the period of operation and reclamation. If an earthquake did occur, the degree of damage and injury to workers would depend on the magnitude of the event and the phase of construction. Although unlikely, if the Sargent splay fault ruptured, it could damage the access road improvements and the Phase 3 and 4 conveyor belt (to be constructed in 2046) at the point that they intersect the fault, but damage would be localized and minor because substantial surface offset is unlikely. The impact of fault rupture during construction is less than significant.

Operation
Mining Pits
Surface fault rupture from the Sargent splay fault could cause slope instability and trigger localized landsliding in the Phase 1 and 2 pits leading to some disruption and sloughing of quarry material on the slopes but would be contained by the benching system on the quarry slopes. The impact would be less than significant.

Phase 1 and 2 Conveyor Belt, Processing Plant, Tar Creek Bridge, and Rail Spur An earthquake on the Sargent or a larger regional fault that is capable of causing surface rupture across the Sargent splay fault is possible but not likely. The processing plant, Phase 1 and 2 conveyor belt, Tar Creek bridge, and rail spur would not be affected because these facilities do not cross the trace of the fault.

Phase 3 and 4 Conveyor Belt, Access Roads, Road Improvements Although unlikely, if fault rupture did occur along the Sargent splay fault, ground deformation could occur as localized surface offsets causing minor damage to the roadway improvement, the Phase 3 and 4 conveyor belt, and access roads. If the surface fault offset is sufficient to displace roadway or the conveyor belt equipment, the damage would be likely be minor and repairable.

The risk of loss, injury, or death would be low, and the impact would be less than significant.

Reclamation
Surface fault rupture could cause minor slope instability, sloughing in the reclaimed slopes of the Phase 1 and 2 pits but considering their finished grades (greater than 2:1) damaging failure would be minimal to moderate. The impact would be less than significant.

Summary for Fault Rupture
The probability of surface fault rupture from the Sargent splay fault is low, and damage that could occur would be minor. Furthermore, the Project would not exacerbate future seismic hazards or unstable soils at the Project site that could result in a substantial risk of loss, injury, or death because the project would not place mining construction, operational, or reclamation components

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-20 ESA / D201901577.01
Draft EIR July 2022
across the trace fault. Impacts associated with fault rupture during operation and through reclamation would be less than significant.

Seismic Ground Shaking
The Project lies within a seismically active region of California, which will likely experience an earthquake of magnitude 6.7 or higher before 2045 (Field 2015). Faults capable of producing significant earthquakes and potentially experiencing fault rupture in the Bay Area include the San Andreas, Hayward-Rodgers Creek, Calaveras, Concord–Green Valley, Marsh Creek–Greenville, and the San Gregorio faults and to a lesser degree, potential displacement on the Sargent fault.

The splay fault, located extending through the central portion of the Project site (Phase 1 and 2 area), has a low potential to displace and cause an earthquake because of relatively short length and history of past activity (1.6 million years ago to 700,000 years ago). Given its location between the San Andreas and the Sargent Fault Zones, ground shaking could be strong to violent, depending on the causative fault and location of the epicenter.

Construction
Conveyor Belt, Processing Plant, Tar Creek Bridge, Rail Spur, Road Improvements, Screening Berm
Ground shaking from a large regional earthquake could affect and likely damage site improvements under construction. Ground motion could weaken and collapse earthen structures such as berms, road grades, and building pads, and potentially cause injury to workers. This is an inherent risk with projects constructed in this or any seismically active region. However, Project construction would not exacerbate future seismic hazards or unstable soil conditions. The Project would not increase the risk of loss, injury, or death during an earthquake because road grading, earthen berms, slope improvements, and structural elements would be designed to building code standards, thereby making them more resistant to earthquake ground shaking. The impact of seismic ground shaking during construction would therefore be less than significant.

Operation and Reclamation
Mining Pits
Strong ground shaking could weaken slopes within the mining pits during operation and after reclamation. The most substantial effects would likely be during operation when mining slopes are being excavated. During this period, the slopes would be at the steepest inclinations with no vegetation and susceptible to failure during an earthquake. Degree of failure would depend on the magnitude of the earthquake, location of the slopes and the slopes’ response to ground motion.

The stability of mining slopes under earthquake ground shaking conditions is discussed further in Impact 3.7-2. During and after reclamation activities, mining pit slopes would be “laid back” to reduce steepness and would be vegetated. Reducing slope steepness and established vegetation would reduce the potential for slope failure during an earthquake.

The potential for earthquakes to be generated from mining operation proposed as part of the Project is very low. Mining on or near active faults can generate low magnitude (i.e., magnitude 2 to 5), localized earth movements (also referred to as micro-earthquakes). These events are generally

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-21 ESA / D201901577.01
Draft EIR July 2022
associated with surface or subsurface mines that extend deep into the earth where localized fault displacement can be triggered by earth pressures that are created by subsurface blasting, large water impoundments, and/or by localized upwarping.16 However, the rate of removal and volumes of rock materials that are proposed to be mined would not be sufficient to cause upwarping and noticeable ground motion. Grading to loosen rock would cause ground vibrations but would not generate motion capable of triggering fault displacement. Water impoundments created in the mining area would not be large or deep enough to impose considerable ground pressures.

Conveyor Belts, Access Road, Processing Plant, Rail Spur, and Roadway Improvements Strong to violent ground shaking generated from a regional earthquake could cause damage to built structures and other improvements and could cause injury to site workers. The proposed structural components of the Project, namely the built structures associated with the processing plant, the Tar Creek Bridge, and the above-ground structural elements of the linear components (conveyor belt, rail spur, access road, and roadway improvements) would be required to undergo appropriate design-level geotechnical evaluations prior to final design and construction in accordance with CBC Chapter 18. Implementing the regulatory requirements of the then current CBC, compliance with the Santa Clara County Geologic Ordinance (Title C, Division C12, Chapter IV of the County of Santa Clara Ordinance Code), compliance with the CGS Guidelines for Evaluating and Mitigating Seismic Hazards in California, and ensuring all buildings and structures are constructed in compliance with the law, would be required for Project engineers and building officials, as also detailed in CBC Chapter 18. Compliance with foundation and structural seismic design criteria as required by the CBC and County ordinances, would minimize the potential for damage from strong seismic ground shaking. While the built components (processing plant) and linear structures (conveyor belt, rail spur, access road and roadway improvements) could undergo minor to moderate structural damage during a large earthquake, they would be unlikely to collapse.

Summary for Seismic Ground Shaking
The Project’s proposed mining activity would not increase the likelihood or frequency of earthquakes or enhance the effects of seismic ground shaking that could result in a substantial risk of loss, injury, or death. because the proposed mining activity would not involve deep mining near faults where earth pressures created by the mining could trigger micro-earthquakes. The Project site would experience ground shaking from a major earthquake on a regional fault system sometime during the operation period of the mining and reclamation. Substantial ground shaking could injure site workers. Built structures could be damaged but with the required compliance of building codes, structural collapse is less likely. Access roads and mine slopes could become unstable and fail during an earthquake both during the operational and reclamation phases of the Project. Earthquakerelated ground shaking is an inherent risk of development in a seismically active region. Impacts associated with seismic ground shaking would be less than significant. 16 Upwarping is the upward flexing of earth materials (i.e., bedrock) due to the release of overlying pressures as material is removed during mining)

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-22 ESA / D201901577.01
Draft EIR July 2022
Liquefaction
Liquefaction is a type of earthquake-induced ground failure that occurs when relatively shallow, loose, granular, water-saturated soils behave similarly to a liquid when subject to high-intensity ground shaking. Liquefaction occurs when three general conditions exist: (1) shallow (50 feet bgs or less) groundwater; (2) low-density non-cohesive (granular) soils; and (3) high-intensity ground motion. Saturated, loose to medium-dense, near-surface non-cohesive soils and cohesive soils exhibit the highest liquefaction potential. Liquefaction usually results in horizontal and vertical movement of soils from lateral spreading (i.e., lateral displacement of gently sloping ground) of liquefied materials and post-earthquake settlement of liquefied materials. The effects of liquefaction on level ground include potential seismic settlement, sand boils, ground oscillation, and bearing capacity failures below structures.

Liquefaction zones, as delineated by the County GHZ database17, are located south of the Project boundary between the Union Pacific Railroad tracks and the Pajaro River (at the southern Santa Clara County line) and southeast of Project boundary along the Pajaro River between the Union Pacific Railroad tracks and Betabel Road. A larger area of potential liquefaction hazards is delineated within the younger valley alluvial deposits east and across U.S. 101 from the Project site. These delineated areas of potential liquefaction hazard do not encroach into the proposed mining pit area, proposed processing plant, or proposed roadway improvements.

Construction and Operation
Mining Pits, Conveyor Belts, Access Road, Processing Plant, Rail Spur Liquefaction potential is low within the proposed development footprint of the Project because of the deep groundwater levels and heterogenous mixtures of fine- to coarse-grained geologic materials. No liquefaction hazard zones were identified within the mining pits or areas slated for eventual reclamation. Liquefaction would not impact stationary built structures, including the processing plant, and linear structures such as the conveyor belts, rail spur, and access road because the geologic materials underlying these components are not susceptible to liquefaction.

Roadway Improvements
The proposed roadway improvements would not be susceptible to liquefaction. Zones of liquefaction-susceptible sediments were delineated along the Pajaro River between the Union Pacific Railroad tracks and Betabel Road southeast of the project Boundary but south of the area of the proposed roadway improvements (County of Santa Clara 2012).

Reclamation
Roadway improvements would remain in place to support future cattle ranching uses at the site.

No additional impact would occur during reclamation (relative to construction and operation) because the issue of liquefaction-susceptible sediments would have been addressed at the time of installation of the improvements.
17 Santa Clara County’s GHZ database maps indicate areas within which the County Geologist may require specific geologic reports prior to approval of development applications.

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-23 ESA / D201901577.01
Draft EIR July 2022
Summary for Liquefaction
While there are areas delineated as containing potentially liquefiable materials south and southeast of the Project site along the Pajaro River and east of Highway 101, the proposed mining, processing, subsequent reclamation, and roadway improvements would not intersect these areas. The Project construction, quarry operation or reclamation would not increase the potential of liquefaction. Construction and operational impacts associated with liquefaction would be less than significant.

Summary
The probability of surface fault rupture from the Sargent splay fault is low, and damage that could occur would be minor. The Project site would likely experience ground shaking from a major earthquake on a regional fault system sometime during the operation period of the mining and reclamation. During an earthquake, built structures could be damaged but structural collapse is less likely while access roads and mine slopes could become unstable and fail. There are limited areas delineated as susceptible to liquefaction ground failure along the Pajaro River south, southeast, and east of the Project site, but these areas would not affect the proposed Project components. Seismic hazards are an inherent risk of development in a seismically active region.

However, mining activity proposed by the Project would not increase the likelihood and frequency of earthquakes or enhance the effects of seismic ground shaking that could result in a substantial risk of loss, injury, or death. Impacts associated with seismic hazards would be less than significant
Mitigation: None required.

Significance: Less than significant
_________________________
Impact 3.7-2: Excavation of quarry pits and reclamation would increase the potential for slope instability and slope failure. (Less than Significant with Mitigation Incorporated) This impact assessment corresponds to Significance Criteria (a(iv)) and (c) (see Section 3.7.4.2, above) and addresses the potential for mining pits, road grades, and stockpiles to become unstable and fail. Impacts associated with lateral spreading, soil collapse, and subsidence are not considered in this analysis. Lateral spreading can occur on slopes and near-level ground undergoing liquefaction during an earthquake. Lateral spreading is not relevant for the project because areas with liquefaction potential do not intersect Project components. Soil collapse and subsidence also are not considered in this impact analysis because the Project site is underlain by dense, consolidated marine and non-marine sediments, which are unlikely to collapse under seismic or non-seismic conditions. Further, the Project site does not overlie a groundwater basin and is therefore not susceptible to subsidence either through withdrawal groundwater or from seismic ground shaking. See additional discussion of lateral spreading, subsidence, and soil collapse in Section 3.7.4.2, Significance Criteria.

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-24 ESA / D201901577.01
Draft EIR July 2022
Construction
Construction of the processing plant, conveyor belts, access road, Tar Creek bridge, road improvements, and rails spur would not cause or exacerbate slope instability or failure because construction activities do not involve grading high slopes or over-steepening existing slopes.

Operation and Reclamation
Processing Plant, Rail Spur
Project components outside the active mining area and mining pit reclamation areas, including the processing plant, rail spur, and access roads would not be impacted from slope instability or failure, because they would be constructed at grade on relatively flat land.

Mining Pits, Conveyor Belts, and Access Roads
Slope instability could occur on the mining pit slopes during the pre-mining period, during active mining, and during and following reclamation. In addition, given that the conveyor and internal access roads are proposed to be in graded areas adjacent to slopes and near the pits, these components could be impacted by slope instability and failure if it were to occur during mining.

SGS completed its soil stability analysis in September 2016 (SGS 2016) and in January 2017, Golder Associates (Golder) performed a comprehensive technical review of the SGS methodology and assumptions. SGS then performed additional slope stability analysis (SGS 2017). Golder submitted a response in October 2017 (Golder 2017b) and concurred with the Applicant’s conclusion that slope failure is a potential hazard, both during quarry operation and reclamation, and concluded that the Project appears to incorporate a practical approach to mitigating the potential slope stability hazard. The County and its environmental consultants have independently reviewed these materials and, together with other information in the record, find them to be suitable for reliance as part of the CEQA process. Accordingly, the analysis below incorporates the initial SGS soils stability analysis (SGS 2016), the Golder peer review (Golder 2017a), the supplemental slope stability analysis (SGS 2017), and Golder’s supplemental geotechnical peer review (Golder 2017b); each of these is provided in Appendix G.

Existing and future stability of a slope can be determined through slope stability modeling that considers the characteristics of the geologic materials, steepness, the orientation of the underlying beds, the depth to groundwater beneath the slope, and the presence of fractures and joints. The results of the modeling analysis provide a factor of safety (FS). The FS is found by dividing the forces that resist movement in the slope (such as cohesion in clays) by the forces that cause movement (i.e., gravity or water). A slope that is stable would have a FS of 1.0 or greater, while slopes below 1.0 would have the potential to fail as a landslide or slump. The less steep a slope is, the higher the FS as it is less prone to failure. Earthquake ground motion represents a force that drives movement and can substantially lower the FS in a slope. Slope failure without earthquake ground motion is referred to static failure and under earthquake forces is referred to as pseudo static or seismic.

SGS (2016) used slope stability modeling to determine the FS for the proposed reclamation slopes in the mining pits. Model results found that in areas where rocks were oriented to incline

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-25 ESA / D201901577.01
Draft EIR July 2022
(dip) toward the mining face at 0 to17-degree angles and/or daylight18 at the mining face, the FS under seismic conditions were below 1.0 (0.68 to 0.81) (SGS 2016). This indicates that these slopes may fail at the proposed reclamation slope of 3:1. In locations where the rock units were oriented across the mining face (cross-bedded), the FS were higher (1.5 to 2.1) indicating they would likely remain stable. At two of the highest, worst‐case slopes at the northwest portion of the proposed mining area, a pseudo‐static analysis indicated an acceptable seismic FS of 1.26 to 1.34 (SGS 2016).

Proposed reclamation slopes that would be at an inclination of 2:1 (with 10-foot benches every 30 feet vertically), were found to be marginally stable to unstable under static conditions, but the modeling showed that reducing the slope to 3.5:1 to 4:1 improved the FS in the range of 1.0 to

1.3. However, analysis under seismic conditions resulted in an FS less than 1.0. It should be noted that the calculations used for the seismic conditions utilized conservative seismic coefficients19 and the use of more standard coefficients could result in a significantly higher FS. Further, this analysis is based on assumptions related to buried soil conditions that cannot be verified until mining occurs, and the soil conditions are exposed (SGS 2016).

The Project includes 105 acres of geotechnical setback areas to address instability under static and seismic conditions and to allow area for landslide remediation if needed. A geotechnical setback buffer allows a safe setback between cut slopes and adjacent areas, and to account for any unanticipated slope instability associated with mining activities. These areas are upslope from the quarry highwalls so slopes can be flattened to 3:1 to 4:1 if needed to improve slope stability during operation or at reclamation. These geotechnical setback areas would not be mined but may be excavated to lay back the slope of a quarry wall to achieve greater stability.

SGS (2016) concluded that the site geology is complex and that minor to moderate failure of pit walls could occur both during excavation and at final reclaimed orientations. The type of rock and sediment, as well as the highly sheared and deformed character of these materials near faults, would affect the overall mass strength of the bedrock materials creating localized conditions susceptible to potential slope instabilities (SGS 2016). Slope stability of the quarry cut slopes during mining operation could be below the required FS, as specified by generally accepted engineering practices and MSHA safety regulations. These slopes could fail under certain conditions encountered during mining (i.e., exposing weak bedding, groundwater). Despite the inclusion of the geotechnical contingency areas, slope failure could result in loss, injury, or death of workers within the mining area or adversely impact biological habitat if a significant seismicinduced or static slide occurs involving areas outside the designated mining locations.

Reclamation slopes may undergo failure under seismic loading and may comply with SMARA standards. This impact is significant because excavation of quarry pits and reclamation would increase the potential for slope instability and slope failure. 18 Daylighting means an exposure of a planer surface (layer or “bed” a rock or fault face) by an open cut (i.e., vertical mining pit face) whose angle is steeper than the exposed bed or fault. 19 A seismic coefficient is used in seismic analysis and represents the amount of horizontal acceleration a structure would be subjected to. The acceleration due to gravity (g), is approximately 980 centimeters per second squared. In terms of automobile acceleration, 1 “g” of acceleration is equivalent to the motion of a car traveling 328 feet from rest in 4.5 seconds.

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-26 ESA / D201901577.01
Draft EIR July 2022
Mitigation Measure 3.7-2a: This mitigation measure applies to the mining pits during mining and reclamation. Throughout the mining operation and reclamation slope grading, the Applicant shall retain a licensed geotechnical engineer to inspect the mining area and monitor construction of the quarry cut slopes twice annually and each time a new 30-foot bench has been excavated. Upon completion of each inspection, the geotechnical engineer shall submit a report to the County and Applicant detailing observations of subsurface conditions, descriptions of potential in-slope failure mechanism (i.e., failure planes, faults, jointing, existing failure planes, and groundwater seepage) or any other concerns regarding the stability of the cut slopes. The geotechnical engineer shall prescribe remedial actions that shall be implemented by the Applicant. Remedial actions could include adjustments to proposed slope configurations (i.e., decreasing slope angle or attitude), additional groundwater seepage management, removal of failure-prone materials, and/or performing additional data collection and slope stability monitoring.

After the report has been reviewed and approved by the County Department of Planning and Development, the Applicant shall implement the remedial actions in compliance with a timeline established by the County.

Mitigation Measure 3.7-2b: This mitigation measure applies to the mining pits during mining. During quarry operation, the Applicant shall implement a combination of the following measures to ensure slope stability:
• Localized layback, earth buttresses, and/or stabilization fills of individual slopes to accommodate for unfavorable bedding. This measure would be required when bedding is observed to be oriented and inclined and/or daylights toward the mining pit. This condition could indicate inherent instability in the slope. • Remedial grading to remove in-place clayey topsoil/colluvium below the proposed stockpiles. This measure would remove potentially unstable or weak topsoil and loose colluvium from the base of the stockpile to ensure the stockpile is founded on competent material, reducing the likelihood of failure. • Waste pile buttress fills or backfill to contain or mitigate surficial and/or minor translational failures.20 This measure would be implemented when beds are observed to be oriented and inclined and/or daylight toward the mining pit and appear to have the potential to fail.
• For groundwater seepage, dewatering by horizontal drains, deep cutoff trenches, or gabion buttresses. Removal of groundwater would be necessary to reduce failure potential in a slope. Groundwater increases the potential of failure by adding weight to the slope and reducing the friction forces in soils and rock.

Observation and inspection during excavation of the quarry pits by a California Certified Engineering Geologist retained by the Applicant shall occur at a minimum of twice per year or any time that mining operations encounter conditions that vary significantly from conditions described in the Project’s geotechnical slope stability report, for the term that the quarry is operational. The Engineering Geologist shall submit a report for review and approval to the County of Santa Clara Department of Planning and Development recommending any additional operational measures deemed necessary to ensure slope stability.
20 Translational failures involve down-slope displacement of soil-rock material on a surface that is roughly parallel to the ground surface in contrast to a rockfalls or rotational slides.

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-27 ESA / D201901577.01
Draft EIR July 2022
Mitigation Measure 3.7-2c: This mitigation measure applies to the mining pits during reclamation. Prior to reclamation slope grading, the Applicant shall develop proposed final slope configurations that address and improve the factors of safety (FS) that are less than 1.0 under seismic loading conditions. The Project Applicant shall demonstrate in its analysis that a pseudo static FS of 1.0 or greater will be achieved by mitigation strategies such as placement of soil buttresses at the toe of slopes vulnerable to failure under seismic loading. In conjunction with Mitigation Measures 3.7-2a and 3.7-2b, the analysis and mitigation strategies prescribed by the measure would provide the supplemental information needed to demonstrate compliance with SMARA at reclamation.

Significance after Mitigation: Less than significant
Implementation of Mitigation Measures 3.7-2a, 3.7-2b, and 3.7-2c would provide ongoing review of localized conditions that indicate susceptibility to slope failure while mining is underway and at the time new mining slopes are excavated. Continual periodic inspection and evaluation throughout the mining phase of the Project would attain additional data and increase the overall understanding of the geologic structure and its response to mining excavation, thereby providing quarry engineers necessary information to inform and implement appropriate mitigation measures for a particular area. With ongoing evaluation of conditions and application of slope stability mitigation, impacts associated with slope stability and possible slope failure during mining and reclamation would be less than significant.
_________________________
Impact 3.7-3: Activities associated with construction, mining and reclamation could result in accelerated erosion and loss of topsoil. (Less than significant) This impact discussion corresponds to Significance Criterion (b) (see Section 3.7.4.2, above) and addresses the accelerated erosion and the loss of topsoil. This impact applies to the construction of the access roads, conveyor belts, processing plant, rail spur, and road improvements, and to operation and reclamation of the mining pits, access road, and roadway improvements.

Construction
Conveyor Belts, Access Roads, Processing Plant, Rail Spur, and Roadway Improvements
Erosion and sedimentation management during the construction phase of the Project would adhere to the requirements of the Construction General Permit (CGP) (see Section 3.10, Hydrology and Water Quality). Construction activities include site grubbing21 and clearing, access road construction (cut and fill slopes), sediment pond and staging area grading, and foundation pad grading. All of these activities expose bare soil, loosening it from its matrix to become susceptible to transportation by wind, rain, and vehicle traffic. The CGP requires the Applicant or its contractor(s) to implement construction Best Management Practices (BMPs) in accordance with a detailed construction Stormwater Pollution Prevention Plan (SWPPP). SWPPPs prescribe required erosion control and stormwater quality BMPs necessary to minimize pollutants in stormwater runoff. The BMPs are 21 Grubbing is the operation to remove and disposing of all unwanted vegetative matter from underground, such as stumps, roots, buried logs, and other debris.

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-28 ESA / D201901577.01
Draft EIR July 2022
designed to prevent pollutants from contacting stormwater and to keep potential contaminants associated with construction activities from leaving the site. Given the CGP and SWPPP, the impacts of accelerated erosion and loss of topsoil during construction would be less than significant.

Operation and Reclamation
Mining Pits, Access Road, and Roadway Improvements
The Project would reduce the potential loss of native topsoil by removing and stockpiling it prior to mining and then redistributing and replacing it during reclamation.

Soil erosion could occur throughout the mining and reclamation phases of the Project during overburden removal and stockpiling, and mining. Highly concentrated storm runoff during the wet season, particularly in response to prolonged, intense storms, can result in accelerated erosion, which, with removal of vegetation and the exposure of bare soil surfaces to rain and vehicle operation, can form rills22 and gullies.23 In some cases, excessive runoff can cause gullies to expand in width and depth to a size capable causing damage to foundations, buildings, utilities, and roads. Accelerated erosion could cause the removal and loss of topsoil. Erosion could produce sediment that can be introduced to Sargent Creek, Tar Creek and eventually the Pajaro River.

Eroded sediment could also enter and clog engineered facilities, such as drainage ditches and culverts; or be deposited at undesirable locations such as road surfaces, parking/staging areas, or working areas. Increased sedimentation also would require more frequent sediment removal from the sedimentation ponds.

Project operation would be required to adhere to the NPDES Permit for Industrial Activities (see Section 3.10.2.2), which includes specific water quality and hydrologic standards and requires monitoring of specified pollutants associated with the covered industrial activity and the subsequent correction of any water quality exceedances indicated by monitoring and reporting. The NPDES Permit also requires implementation of a Stormwater Pollution Prevention Plan (SWPPP), which has been prepared for the Project (Appendix I.4). The SWPPP includes a range of BMPs to control erosion, such as the use of water trucks to spray unpaved and paved roads, restriction of activities during wet weather, routine inspection of the access roads for erosion and/or spills, the expansion of drainage facilities and sedimentation basins (as needed), and the use of jute matting, erosion control blankets, wattles, silt fences and sediment traps to mitigate areas where runoff is concentrated to reduce sediment levels in site runoff. Soils would be revegetated as needed during operation to control erosion.

Ultimately, the entire site would be revegetated as part of reclamation, as discussed in Section 2.6.4 in Chapter 2. The Reclamation Plan includes specific standards and BMPs related to re-soiling, back filling, grading, slope stabilization, removal of structures and equipment, control of contaminants, erosion and sedimentation, and the protection of on-site and downstream beneficial uses of water (see Reclamation Plan, Section 4.5, Appendix B). Erosion and sediment control measures to be implemented during the reclamation phases of the project would include revegetation of disturbed slopes, benches, and valley floor areas. The 22 A rill is a small channel cut out by water flowing over loose or otherwise erosion-susceptible soils. 23 Gullies form when rills increase in size and carry and increased amount of water.

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-29 ESA / D201901577.01
Draft EIR July 2022
implementation of BMPs, such as jute matting, erosion control blankets, wattles, silt fences and sediment traps, would ensure areas where runoff is concentrated are managed such that erosion and the transport of sediment or other pollutants in the runoff is avoided or minimized.

Summary
During construction, the CGP and associated SWPPP would minimize erosion and loss of topsoil.

Compliance with the requirements of the NPDES Industrial Permit, including the implementation of associated BMPs as part of the SWPPP, as well as the requirements of SMARA and County Use Permit related to mining and reclamation, would manage surface water flows to reduce erosion damage caused by uncontrolled surface water runoff during large rain events, especially on bare ground, quarry slopes and stockpiles. Given these measures, the impacts of erosion and loss of topsoil during operations would be less than significant.

Mitigation: None required.

Significance: Less than significant
_________________________
Impact 3.7-4: The site soils would not be incompatible with the proposed On-Site Wastewater Treatment System (OWTS). (Less than Significant) This impact discussion corresponds to Significance Criterion (e) (see Section 3.7.4.2, above) and evaluates whether soils on the site are compatible with the development and use of an OWTS.

Construction and Operation
Mining Pits, Conveyor Belts, Access Roads, and Roadway Improvements The on-site wastewater treatment plant would be located at the proposed processing plant. Therefore, this impact discussion applies to construction and operation of the processing plant only and is not applicable to the mining pits, conveyor belt, rail spur, access roads, or roadway improvements.

Processing Plant
The Project proposes installation of a new on-site septic system, or OWTS, near the processing plant to treat wastewater generated by toilets and sinks in the processing plant office, as well as one additional restroom facility in the processing plant area. The OWTS would be located near the processing plant and the leachfield would be placed in soils consisting of Zamora Clay Loam overlying older alluvial deposits. These soils are considered well-drained and would likely be suitable for an operable leachfield. The OWTS design and installation would be reviewed by the County of Santa Clara DEH through its permit process, consistent with Section B11-60 through

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-30 ESA / D201901577.01
Draft EIR July 2022
B11-95 of the County Ordinance Code. Soils types and percolation rates of soils within the leachfield and the system design would be reviewed for consistency with County OWTS requirements to ensure health hazards and nuisance conditions would not occur and that surface water and groundwater would not be significantly impacted. Testing as part of the permit process would ensure that on-site soils are capable of adequately supporting the OWTS.

The OWTS would require review, permitting, and, if certain alternative methods are used or if needed setbacks cannot be maintained, a renewable operating permit with inspections would be issued by the DEH. Because the new OWTS would be designed and constructed consistent with DEH requirements, and those requirements would require compliance prior to construction and operation to help assure soils would be capable of adequately supporting the use of the OWTS, this impact would be less than significant.

Reclamation
During final reclamation, the OWTS either would be abandoned per the terms of an abandonment permit from the County DEH subject to County Ordinance Code Section B11-86 or may be kept in operation to support cattle ranching uses. Under either circumstance, no additional impact would occur during reclamation because the issue of soil suitability would have been addressed at the time of installation of the OWTS.

Mitigation: None required.

Significance: Less than significant
_________________________
Impact 3.7-5: Project excavation and grading could adversely affect paleontological resources. (Significant and Unavoidable)
This impact discussion corresponds to Significance Criterion (f) (see Section 3.7.4.2, above) and evaluates whether the Project would adversely affect paleontological resources. Technical information relied upon for this analysis is presented in the PaleoSolutions report provided as Appendix G.2.

The SVP has established guidelines for the identification, assessment, and mitigation of adverse impacts on nonrenewable paleontological resources (SVP 2010). Most practicing paleontologists in the nation adhere closely to the SVP’s assessment, mitigation, and monitoring requirements as outlined in these guidelines, which were approved through a consensus of professional paleontologists and are the standard against which paleontological monitoring and mitigation programs are judged. The mitigation proposed for this impact relies on the definitions, methods, and qualifications described in these guidelines.

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-31 ESA / D201901577.01
Draft EIR July 2022
Construction
Mining Pits
Because the impacts of excavation within the mining pits would be ongoing during mining (operation) phases, paleontological impacts related to mining are addressed below under Operation.

This includes the portions of the access road and conveyor belt alignments that are located within the mining pits as shown in Figures 2-9 and 2-10.

Conveyor Belts, Access Roads, Processing Plant, and Rail Spur Grading and site clearing for development of the processing plant, rail spur, and much of the length of the conveyor belt and access road to Phases 3 and 4 would occur within Holocene-age alluvial deposits (Qa) with a PFYC of 2 (low), and this low potential to encounter fossils combined with the shallow nature of grading and excavation required for these components means that their impact would be less than significant. Small portions of the access road and conveyor belt alignment that fall outside of the mining pits could cross areas mapped as Etchegoin Formation (Te) with a PFYC of 4 (high). Grading, excavation, and placement of conveyor belt support structures for these facilities may have a high potential to destroy paleontological resources in the limited portions of these components located within the Etchegoin Formation, a significant impact.

Roadway Improvements
The proposed improvements to the existing Old Monterey Road would not result in excavation and therefore would have no impact on paleontological resources. The proposed U.S. 101 Northbound acceleration lane improvements would occur within Holocene-age alluvial deposits (Qa) with a PFYC of 2 (low) and a small area Quaternary older alluvium (Qoa) with a PFYC of 3 (moderate). The free-span bridge over Tar Creek also would be installed within an area mapped as Holocene alluvium (Qa) with a PFYC of 2 (low). The low to moderate potential to encounter fossils combined with the small amount of grading in areas of PFYC 2 and 3 and excavation limited to areas of PFYC 3 would result in a low potential to destroy paleontological resources, and the impact from these components would be less than significant.

Operation
Mining Pits
The proposed Sargent Quarry would be an open-pit sand and gravel quarry with surface mining occurring in four phases over 30 years. Sand and gravel deposits would be excavated to an approximate depth of 200 feet above sea level. No underground mining would occur; rather, hillslopes within mining areas would be cut back and mined over time, with the quarry floor no deeper than the base of the hillslopes, for an approximately 400-foot reduction in elevation when mining is complete.

Surface mining has the potential to uncover and damage fossil resources primarily in areas mapped as Etchegoin Formation (Te) with a PFYC of 4 (high) and unnamed Pliocene claystone (Tn) with a PFYC of U (unknown), along with small areas of Holocene alluvium (Qa) and landslide deposits (Qls) each with a PFYC of 2 (low). Nearly all of Phases 1 and 2 would be located in the Etchegoin Formation, and Phases 3 and 4 would be mostly within Etchegoin Formation and partially within

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-32 ESA / D201901577.01
Draft EIR July 2022
Pliocene claystone. While shallow excavations into Holocene alluvium and landslide deposits are unlikely to uncover significant fossil vertebrate remains, these deposits may overlie older paleontologically sensitive sedimentary deposits. Therefore, all of the excavation associated with surface mining in each of the phases has high potential to uncover paleontological resources.

Destruction of heritage paleontological resources would be a significant impact.

Processing Plant, Rail Spur, Conveyor Belt, Access Road, and Roadway Improvements
Operation of the processing plant and associated facilities and the roadway improvements would not uncover, disturb, or damage paleontological resources, because there would not be any ongoing excavation in these areas; therefore, there would be no impact associated with long-term operation of these Project components.

Reclamation
Although reclamation activities would involve minor ground disturbance, all of the areas to be reclaimed would have been previously disturbed during construction and operation. Therefore, any impacts on paleontological resources would have occurred during those phases, and reclamation would have no additional impact on paleontological resources.

Summary
Construction of the processing plant, rail spur, conveyor belt, access road, and roadway improvements has low potential to disturb or destroy unique paleontological resources, except within small areas of moderate to high potential where the conveyor belt and access road cross areas mapped as Etchegoin Formation (Te) and the U.S. 101 improvements cross Quaternary older alluvium (Qoa). Destruction of heritage paleontological resources, most likely to occur in these high and moderate potential areas (PFYC 3 and 4), would be a significant impact.

Mining activities, including excavation and grading associated with the Project, have the potential to uncover and damage heritage paleontological resources important to the County of Santa Clara.

This impact is significant due to the extensive excavation associated with mining activities in areas with high, moderate, and unknown potential for paleontological.

Mitigation Measure 3.7-5: This measure applies to construction of the Phase 3 and 4 conveyor belt and access road within areas mapped as Etchegoin Formation (Te) with a PFYC of 4 (high), as well as to all ground-disturbing activities (whether considered construction or operation) within the mining pits (Phases 1 through 4) and geotechnical setback areas.

The Applicant shall retain a qualified paleontologist meeting Society of Vertebrate Paleontology (SVP) standards to oversee the preparation of a paleontological resources monitoring plan (PRMP). The PRMP shall be prepared prior to the start of construction and mining activities, reviewed and approved by the County Department of Planning and Development, and implemented by a qualified paleontologist. The PRMP shall provide guidance for paleontological field surveys, fossil sampling, spot checking/monitoring, reporting, curation, and on-call response to fossil discoveries that occur for the duration of the Project construction and operation. The PRMP shall detail the following components:

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-33 ESA / D201901577.01
Draft EIR July 2022
a) Worker Training. The qualified paleontologist shall prepare and implement a worker training program to inform construction and mining personnel of the possibility for fossil discoveries. The training program shall provide an overview of the paleontological sensitivity of the site and the potential to uncover fossil remains. The training program shall instruct personnel to immediately inform their supervisor if any bones, teeth, or other substantial fossil remains are unearthed. In such a case, workers shall immediately cease activity within a 50-foot radius of the discovery site until a qualified paleontologist can examine and evaluate the find per item (b) below. Work may not resume in the discovery area until it has been authorized by the County. The training shall be provided to new personnel prior to beginning work on the site and such trainings should be coordinated with the site manager and should coincide with spot checking/sampling visits. Verification of training will be provided as an appendix to the annual report submitted to the County Department of Planning and Development described in item (f). b) Evaluation and Salvage of Fossils. If any bones, teeth, or other fossil remains are unearthed in the course of ground disturbance, work will cease as directed in item (a) and a qualified paleontologist will examine and evaluate the find. In the event that the qualified paleontologist deems the fossil significant according to SVP Guidelines (2010) and recommends it for curation, the qualified paleontologist shall propose salvage measures in consultation with the Applicant, and the salvage measures shall be reviewed and approved by the County Department of Planning and Development and shall be carried out by or under the direct supervision of the qualified paleontologist. Curation shall follow the process directed in item (e).
c) Paleontological Survey. At least 30 days prior to the start of surface disturbance in any new portion of the Project site that is not low potential (e.g., at the beginning of the Project construction period, when construction on the Phase 3 and 4 access road and conveyor belt begins, or when excavation of a new mining phase begins), a paleontological survey shall be conducted by a qualified paleontologist for the area to be disturbed to allow for in situ documentation and collection of surficial fossils.

Following each survey, a paleontological survey memorandum shall be prepared. The first survey memorandum prior to the start of construction shall be submitted immediately upon completion to the County Department of Planning and Development. Subsequent surveys during the life of the Project can be compiled and submitted as part of the annual paleontological mitigation report described in item (f). d) Spot Checks During Mining. A qualified paleontologist shall conduct periodic spot checks (at least six times per year) for the duration of mining activities that impact native Etchegoin Formation (Te), unnamed claystone (Tn), and Pleistocene older alluvium (Qoa). This includes all of Phases 1 through 4. The qualified paleontologist shall check for the presence of any recently uncovered macrofossils or layers that should be sampled for microfossils. The need for, frequency, and timing of the spot checks shall be outlined in the PRMP, and during implementation the actual need, frequency, and timing shall be based on the PRMP and coordinated with the Applicant based on real-time excavation activities and locations. The frequency of spot-checking efforts in a given portion of the quarry area may be reduced at the recommendation of the qualified paleontologist with approval from the County Department of Planning and Development if it is determined that only previously disturbed, imported, or Holocene-age alluvial sediments are being impacted, or if sediments are deemed to be non-conducive to fossil preservation. Dates and results of spot checks shall be recorded and reported as described in item (f).

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-34 ESA / D201901577.01
Draft EIR July 2022
e) Sample Identification and Curation. The qualified paleontologist shall ensure that all fossils and bulk matrix samples collected at the Project site during work stoppages (if resources are found during ground disturbance), paleontological surveys, or spot checks are removed to a secure paleontological laboratory within 30 days of collection from the field for preparation to the point of identification and curation in accordance with SVP Guidelines (2010). All data, including the results of the analysis and research on the fossil collection, shall be compiled along with the fossil specimen inventory and detailed paleontological locality forms, maps, and photos for inclusion in the annual paleontological mitigation report described in item (f). f) Annual Reporting. The annual paleontological mitigation report shall be submitted to the County Department of Planning and Development and, if fossils are discovered, to the University of California Museum of Paleontology (or other equivalent fossil repository). The annual paleontological mitigation report shall also include dates of field work, results of spot checking, survey and sampling, fossil analyses, significance evaluation, conclusions and future recommendations, locality forms, and an itemized list of specimens. Detailed survey reports and verification of new mining personnel paleontology trainings shall be included as appendices. The PRMP shall identify an annual due date for the report.

Significance after Mitigation: Less than significant for construction; significant and unavoidable for operation.

Implementation of Mitigation Measure 3.7-5 would reduce the potential to inadvertently destroy paleontological resources during construction by conducting pre-construction surveys of areas that have the potential to contain such resources, by training workers to recognize such resources if they are uncovered during construction, and by ensuring that resources that are discovered during either surveys or excavation activities are treated appropriately. Because this measure would provide for the identification and curation of most or all fossils that could be encountered during the limited construction-period ground disturbance in high fossil potential areas, the construction-period impact would be reduced to less than significant with mitigation.

During Project operation, implementation of Mitigation Measure 3.7-5 would reduce the potential to inadvertently destroy paleontological resources through periodic surveys of areas that have the potential to contain such resources, training workers to recognize such resources if they are uncovered during operation, and ensuring that resources that are discovered during either surveys or excavation activities are treated appropriately through the implementation of a monitoring plan to ensure preservation of paleontological resources. Spot checks would be required in the monitoring plan throughout the mining period as well as salvaging and preparing significant fossil finds for curation, which would increase the likelihood that such resources are identified prior to being damaged by project activities. Full-time monitoring for the life of the project is not feasible, particularly given that there are geologic units of both high and moderate and unknown paleontological potential within the Project site. For these reasons, the potential for inadvertent damage to or destruction of paleontological resources would remain.

Therefore, this impact would therefore remain significant and unavoidable during operation.
_________________________

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-35 ESA / D201901577.01
Draft EIR July 2022

3.7.4.4 Cumulative Analysis
Geology and soils impacts tend to be site-specific and depend on the local conditions. For these reasons, the geographic context for potential cumulative impacts of geology, seismic hazards, and soil resources is the Project site and areas in the site vicinity with similar soil and geologic conditions. For example, slope failure would occur only on the Project site and would not trigger slope failures off-site or at the sites of cumulative projects listed in Table 3.1-1. While the Project could exacerbate slope instability within the mining pits, it would be confined to the site and would not combine with projects on adjacent sites or with any other off-site projects. For these reasons, the Project would not contribute to cumulative geologic or soils impacts.

The cumulative context for paleontological resources includes those areas in the Project vicinity in areas that have geologic conditions similar to the Project site.

Impact 3.7-6: The Project would contribute to the cumulative loss of paleontological resources. (Significant and Unavoidable)
The Project would result in a significant paleontological resources impact during operation, as the deep excavation in the surface mining pits would occur in areas with high, moderate, and unknown potential for paleontological resources as shown in Figure 3.7-1. The cumulative projects would be located in areas of primarily low paleontological sensitivity, with small pockets of moderate sensitivity. The primary cumulative project that would contribute to a cumulative impact in combination with the Project is the U.S. 101 widening from Monterey Road to SR 129, which would occur mostly within areas of low potential (Qa, PFYC 2) but may extend into some areas mapped as moderate (Qoa, PFYC 3) to high (Te, PFYC 4) potential. Paleontological mitigation measures for the US 101 widening project are unknown as of publication of this Draft EIR.

However, monitoring for fossils is feasible given the short-term nature of roadway construction.

Such monitoring could reduce the US 101 widening project’s potential contribution to cumulative paleontological impacts. However, due to the large area of excavation associated with this Project’s proposed surface mining, the cumulative paleontological impact would be significant, and the Project’s contribution would be cumulatively considerable and thus significant.

Mitigation Measure 3.7-6: Implement Mitigation Measure 3.7-5 (requiring worker training, surveys, spot checks, curation, and annual reporting). Mitigation Measure 3.7-5 would reduce the impact on paleontological resources, but for the reasons described in Impact 3.7-5, it would not reduce impacts to below the level of significance. Therefore, the overall impact would remain cumulatively considerable and significant and unavoidable, with the Project making the primary contribution to this impact.

Significance after Mitigation: Significant and unavoidable _________________________

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-36 ESA / D201901577.01
Draft EIR July 2022

3.7.5 References
Bryant, William A., and E.W. Hart. 2007. Fault Rupture Hazard Zones in California, Alquist Priolo Earthquake Fault Zoning Act, with index to Earthquake Fault Zones Maps. Interim Revision. Special Publication 42. California Department of Conservation Geological Survey.

Bureau of Land Management (BLM). 2016. Potential Fossil Yield Classification System. https:// www.blm.gov/sites/blm.gov/files/uploads/IM2016-124_att1.pdf.

California Department of General Services (DGS). Building Standards Commission, California.

Building Standards Code (California Code of Regulations, Title 24). https://codes.iccsafe.org/content/CBC2019P4. Accessed March 31, 2020.

California Geological Survey (CGS). 2002. California Geomorphic Provinces. Fact Sheet 36.

Revised December 2002.

County of Santa Clara. 2021. County Geologic Hazard Zones. Department of Planning and Development. https://sccplanning.maps.arcgis.com/apps/webappviewer/index.html?id=5ef8 100336234fbdafc5769494cfe373 Accessed July 6, 2021.

County of Santa Clara. 1994. Santa Clara County General Plan, Part 3: Rural Unincorporated Area Issues & Policies. Adopted December 20, 1994.

County of Santa Clara, 2020. Santa Clara County Surface Mining Ordinance, Sections 2.10.040 and

4.10.370.

Dibblee, T. and E. Brabb. 1978. Preliminary Geologic Map of the Chittenden Quadrangle, Santa Clara, Santa Cruz, and San Benito Counties, California. USGS Open File Report, 78-453.

Dibblee, T Jr. and J. Minch. 2006. Geologic Map of the Chittenden quadrangle, Santa Clara, Santa Clara, Santa Cruz & San Benito Counties, California. Dibblee Foundation Map DF228. Scale 1:24,000.

Field, E.H. and 2014 Working Group on California Earthquake Probabilities, 2015, UCERF3: A new earthquake forecast for California’s complex fault system: U.S. Geological Survey 2015–3009, 6 p., http://dx.doi.org/10.3133/fs20153009.

Freeman Associates. 2022. Sargent Quarry Mining and Reclamation Plan. February 2022.

Golder Associates. 2017a. Geotechnical Peer Review, Sargent Ranch Quarry, Santa Clara County. January 19, 2017.

Golder Associates. 2017b. Supplemental Geotechnical Peer Review, Sargent Ranch Quarry, Santa Clara County. October 13, 2017.

Graymer, R.W. 1997. Geology of the southernmost part of Santa Clara County, California; a digital database: U.S. Geological Survey Open-File Report 97–710. (Available at https:// pubs.usgs.gov/of/1997/of97-710/.)
Jackson, Julia. 1997. Glossary of Geology. American Geological Institute. Fourth Edition.

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-37 ESA / D201901577.01
Draft EIR July 2022
Jennings, C. and R. Strand. 1958. Santa Cruz Sheet. Geologic Map of California. California Geological Survey.

Paleo Solutions. 2017. Paleontological Technical Report: Sargent Quarry Project, Unincorporated Santa Clara County, California. January.

Santa Clara County Department of Environmental Health (DEH). 2018. Introducing the New Santa Clara County Onsite Wastewater Treatment System Ordinance: Frequently Asked Questions. https://www.sccgov.org/sites/cpd/programs/LU/Documents/ LU_OWTS_FAQS.pdf. Accessed August 28, 2018.

Sierra Geotechnical Services, Inc. (SGS). 2016. Revised Geotechnical Slope Stability Report.

Sargent Ranch Quarry Site, Sargent, Santa Clara County, California. September 12, 2016.

Sierra Geotechnical Services, Inc. (SGS). 2017. Response to Review Comments. Sargent Ranch Quarry Site, Sargent, Santa Clara County, California. August 28, 2017.

Society of Vertebrate Paleontology (SVP). 2010. Standard Procedures for the Assessment and Mitigation of Adverse Impacts to Paleontological Resources. https://vertpaleo.org/wpcontent/uploads/2021/01/SVP_Impact_Mitigation_Guidelines.pdf U.S. Department of Agriculture (USDA) NRCS. 2020. Soil Data Access (SDA) Prime and other Important Farmlands. https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/ nrcseprd1338623.html#reportref Accessed March 17, 2020.

Wagner, D.L. et al. 2002. Geologic Map of the Monterey 30' x 60' Quadrangle and Adjacent Areas, California.

3. Environmental Setting, Impacts, and Mitigation Measures

3.7 Geology, Soils, and Paleontological Resources
Sargent Quarry 3.7-38 ESA / D201901577.01
Draft EIR July 2022
This page intentionally left blank

3. Environmental Setting, Impacts, and Mitigation Measures

3.8 Greenhouse Gas Emissions
Sargent Quarry 3.8-1 ESA / D201901577.01
Draft EIR July 2022

3.8 Greenhouse Gas Emissions

3.8.1 Introduction
This section evaluates the greenhouse gas (GHG) emissions impacts of the Project. The following discussion is based, in part, on a GHG emissions calculations prepared by Illingworth & Rodkin, Inc. in February 2017 and revised in August of 2021 (Illingworth & Rodkin, Inc. 2021). Calculation tables and model output from that analysis are included as Appendix D to this EIR.

3.8.1.1 Greenhouse Gas Emissions and Global Climate Change Climate change is caused by GHGs emitted into the atmosphere around the world from a variety of sources, including the combustion of fuel for energy and transportation, cement manufacturing, and refrigerant emissions. GHGs are those gases that have the ability to trap heat in the atmosphere, a process that is analogous to the way a greenhouse traps heat. GHGs may be emitted as a result of human activities, as well as through natural processes. Increasing GHG concentrations in the atmosphere is leading to global climate change resulting in direct and indirect impacts to loss in snow pack; sea-level rise; more extreme heat days per year; more high ozone days; more extreme forest fires; more severe droughts punctuated by extreme precipitation events; increased erosion of California’s coastlines and sea water intrusion into the Sacramento and San Joaquin Deltas and associated levee systems; and increased pest infestation (OPR 2018).

Carbon dioxide (CO2) is the most important anthropogenic GHG because it comprises the majority of total GHG emissions emitted per year and it is very long-lived in the atmosphere.

Other common GHGs include methane (CH4), nitrous oxide (N2O), and halocarbons (a group of gases containing fluorine, chlorine, or bromine). Typically, when evaluating GHG emissions they are expressed as CO2 equivalents, or CO2e, which is a means of weighting the global warming potential (GWP) of the different gases relative to the global warming effect of CO2, which has a GWP value of one. Other GHGs, such as CH4 and N2O, which are commonly found in the atmosphere, but at much lower concentrations, have a GWP of 21 and 310, respectively. In the United States, CO2 emissions account for about 80 percent of the GHG emissions, followed by CH4 at about 10 percent and nitrous oxide at about 7 percent (USEPA 2021).

3.8.2 Regulatory Setting

3.8.2.1 Federal
The U.S. participates in the United Nations Framework Convention on Climate Change (UNFCCC). In 2007, the U.S. Environmental Protection Agency (USEPA) identified CO2 as an air pollutant as defined under the Clean Air Act, and that the USEPA has the authority to regulate emissions of GHGs. The USEPA has promulgated several GHG regulations, which for the most part, apply to larger facilities that emit large amounts of CO2 or its equivalent in other regulated GHGs. These regulations include the Federal Mandatory Reporting of Greenhouse Gases (Mandatory Reporting Rule) and the Title V Greenhouse Gas Tailoring Rule (Tailoring Rule).

The Mandatory Reporting Rule, which requires reporting of CO2 and other GHG emissions,

3. Environmental Setting, Impacts, and Mitigation Measures

3.8 Greenhouse Gas Emissions
Sargent Quarry 3.8-2 ESA / D201901577.01
Draft EIR July 2022
applies to particular facility types that emit GHGs (primarily large facilities that emit 25,000 metric tons per year or more of CO2e emissions) and to most upstream suppliers of fossil fuels and industrial GHGs, as well as to manufacturers of vehicles and engines (USEPA 2009). Since the quarry would emit well under 25,000 metric tons CO2e per year, it would not be subject to this rule.

The USEPA also issued a rule addressing GHG emissions from stationary sources and requirements under Title V and Prevention of Significant Deterioration (PSD) permitting programs. This rule is known as the PSD and Tailoring Rule. The Sargent Quarry would not be a major GHG source under the PSD or Tailoring Rule permit regulations.

Light-Duty Vehicle Greenhouse Gas and Corporate Average Fuel Economy Standards
In addition to setting emission standards for stationary sources, the USEPA sets nationwide emission standards for mobile sources, which include on-road (highway) motor vehicles such as trucks, buses, and automobiles, and non-road (off-road) vehicles and equipment used in construction, agricultural, industrial, and mining activities (such as bulldozers and loaders). The USEPA also sets nationwide fuel standards, such as the Corporate Average Fuel Economy (CAFE) standards (adopted in 2010) that require improved fuel economy and lower GHG emissions.

In 2018, the USEPA and the U.S. Department of Transportation’s National Highway Traffic Safety Administration (NHTSA) proposed the Safer Affordable Fuel-Efficient (SAFE) Vehicles Rule Part One and Part Two. Part One revokes California’s authority to set its own fuel economy and greenhouse gas standards and zero-emission vehicle mandate, and Part Two increased the federal greenhouse gas emissions and fuel economy standards (84 Federal Register 51,310 for Part One and 85 Federal Register 24,173 for Part Two).

On April 22, 2021, NHTSA proposed to formally roll back portions of the SAFE Rule, thereby restoring California’s right to set more stringent fuel efficiency standards. NHTSA is also planning to issue a new rule to increase the national fuel economy standard for light duty vehicles beyond those in Part Two of the SAFE Vehicles Rule (Federal Register 2021).

3.8.2.2 State
In response to the increasing body of evidence that GHGs will continue to affect the global climate, the State has enacted key legislation and promulgated regulations in an effort to reduce the State’s contribution to climate change.

Executive Orders
There are three primary EOs related to the State’s GHG reduction efforts. In general, EOs provide direction to State government agencies but do not place mandates on regional or local governments or the private sector.
• EO S-03-05: Established GHG-reduction targets for 2010 (2000 emission levels), 2020 (1990 emission levels) and 2050 (80 percent below 1990 levels).

3. Environmental Setting, Impacts, and Mitigation Measures

3.8 Greenhouse Gas Emissions
Sargent Quarry 3.8-3 ESA / D201901577.01
Draft EIR July 2022
• EO S-30-15: Established a GHG reduction target for 2030 (40 percent below 1990 levels). • EO B-55-18: Established a new statewide goal “to achieve carbon neutrality as soon as possible, and no later than 2045, and achieve and maintain net negative emissions thereafter.” This EO directs CARB to ensure future Climate Change Scoping Plans (discussed below) identify and recommend measures to achieve the carbon neutrality goal.

Assembly Bill 1493
California Assembly Bill 1493 of 2002 (Pavley) required the California Air Resources Board (CARB) to develop and adopt regulations that reduce GHGs emitted by passenger vehicles and light duty trucks. Responsive regulations adopted by CARB apply to 2009 and later model year vehicles. CARB estimates that the regulation will reduce GHG emissions from light duty passenger vehicles in California by an estimated 18 percent in 2020 and by 27 percent in 2030 (CARB 2021b).

Assembly Bill 32 and Senate Bill 32
In 2006, Assembly Bill 32 (AB 32), the California Global Warming Solutions Act of 2006 was adopted and codified in California Health and Safety Code Division 25.5. Under AB 32, CARB established a statewide GHG emissions cap for 2020, adopted mandatory reporting rules for significant sources of GHGs, and adopted a comprehensive plan, known as the Climate Change Scoping Plan, identifying how emission reductions would be achieved from significant GHG sources.

In 2016, SB 32 amended the California Global Warming Solution Act. SB 32 and accompanying Executive Order B-30-15 require CARB to ensure that statewide GHG emissions are reduced to 40 percent below the 1990 level by 2030. CARB updated its Climate Change Scoping Plan in December of 2017 (CARB 2017) to express the 2030 statewide target in terms of million metric tons of CO2e (MMTCO2e). The 2008 Climate Change Scoping Plan shows 1990 emissions at 426.6 MMTCO2e (CARB 2008). Based on the emissions reductions directed by SB 32, the annual 2030 statewide target emissions level for California is 260 MMTCO2e. The 2017 Climate Change Scoping Plan identifies measures for how California could achieve the 2030 GHG reduction target established in SB 32,and substantially advance towards the 2050 reduction goal identified in EO S-3-05.

Cap-and-Trade Program
The California Cap-and-Trade Program is a core strategy that the state is using to meet its GHG reduction targets for 2020 and 2030, and ultimately achieve an 80 percent reduction from 1990 levels by 2050. CARB designed and adopted the California Cap-and-Trade Program to reduce GHG emissions from “covered entities” (e.g., electricity generation, petroleum refining, cement production, and large industrial facilities that emit more than 25,000 MTCO2e per year), setting a firm cap on statewide GHG emissions and employing market mechanisms to achieve reductions.

Under the Cap-and-Trade Program, an overall limit is established for GHG emissions from capped sectors. The statewide cap for GHG emissions from the capped sectors commenced in 2013. The cap declines over time. Facilities subject to the cap can trade permits to emit GHGs.

3. Environmental Setting, Impacts, and Mitigation Measures

3.8 Greenhouse Gas Emissions
Sargent Quarry 3.8-4 ESA / D201901577.01
Draft EIR July 2022
Senate Bill 100
On September 10, 2018, Governor Brown signed SB 100, establishing that 100 percent of all electricity in California must be obtained from renewable and zero-carbon energy resources by December 31, 2045. Specifically, the law increases the percentage of energy that both investorowned utilities and publicly-owned utilities must obtain from renewable sources(i.e., the renewables portfolio standard) from 50 percent to 60 percent by 2030. Incrementally, these energy providers must also have a renewable energy supply of 33 percent by 2020, 44 percent by 2024, and 52 percent by 2027.

Senate Bill 375
Senate Bill 375 (SB 375), known as the Sustainable Communities Strategy and Climate Protection Act, was signed into law in September 2008. SB 375 builds upon AB 32 by requiring CARB to develop regional GHG reduction targets for automobile and light truck sectors for 2020 and 2035. The initial per-capita GHG emissions reduction targets for passenger vehicles in the San Francisco Bay Area included a seven percent reduction by 2020 and a 15 percent reduction by 2035. In 2018, CARB set updated targets for a 10 percent reduction by 2020 and a 19 percent reduction by 2035 (CARB 2018).

Senate Bill 1383 (Short-Lived Climate Pollutants)
SB 1383, enacted in 2016, requires statewide reductions in short-lived climate pollutants across various industry sectors. The climate pollutants covered under SB 1383 include methane, fluorinated gases, and black carbon—all GHGs with a much higher warming impact than CO2 and with the potential to have detrimental effects on human health. SB 1383 requires CARB to adopt a strategy to reduce methane by 40 percent, hydrofluorocarbon gases by 40 percent, and anthropogenic black carbon by 50 percent below 2013 levels by 2030. The methane emissions reduction goals include a 75 percent reduction in the level of statewide disposal of organic waste from 2014 levels by 2025.

3.8.2.3 Regional
2017 Clean Air Plan
The BAAQMD prepared the 2017 Clean Air Plan to reduce air pollution, protect public health, and reduce GHG emissions (BAAQMD 2017b). The plan defines a vision for transitioning the region to a post-carbon economy needed to achieve ambitious GHG reduction targets for 2030 and 2050, and provides a regional climate protection strategy that will put the Bay Area on a pathway to achieve those GHG reduction targets.

The 2017 Clean Air Plan includes control measures designed to reduce emissions of CH4 and other super-GHGs that are potent climate pollutants in the near-term, and to decrease emissions of CO2 by reducing fossil fuel combustion.

3. Environmental Setting, Impacts, and Mitigation Measures

3.8 Greenhouse Gas Emissions
Sargent Quarry 3.8-5 ESA / D201901577.01
Draft EIR July 2022
Plan Bay Area
Consistent with the requirements of SB 375, the Metropolitan Transportation Commission (MTC) partnered with the Association of Bay Area Governments (ABAG) to prepare Plan Bay Area 2050, the region’s Sustainable Communities Strategy (SCS), as part of the Regional Transportation Plan process. However, the SCS would not be directly applicable to Sargent Quarry, because the reductions would be achieved through the promotion of compact, highdensity, mixed-use neighborhoods near transit, and alternatives to single passenger vehicle use.

3.8.2.4 Local
County of Santa Clara General Plan
Section G of the Health Element of the Santa Clara County General Plan (County of Santa Clara 2015) addresses GHG and Climate Change. This element includes several GHG-related policies that pertain to this Project:

Policy HE-G.3: Fleet upgrades. Promote Air District mobile source measures to reduce emissions by accelerating the replacement of older, dirtier vehicles and equipment, and by expanding the use of zero emission and plug-in vehicles.

Policy HE-G.4: Off-road sources. Encourage mobile source emission reduction from offroad equipment such as construction, farming, lawn and garden, and recreational vehicles by retrofitting, retiring and replacing equipment and by using alternate fuel vehicles.

Policy HE-G.5: GHG reduction. Support efforts to reduce GHG emissions from mobile sources, such as reducing vehicle trips, vehicle use, vehicle miles traveled (VMT), vehicle idling, and traffic congestion. These efforts may include improved transit service, better roadway system efficiency, state-of-the-art signal timing and Intelligent Transportation Systems (ITS), transportation demand management, parking and roadway pricing strategies, and growth management measures.

Policy HE-G.10: Conservation. Promote energy conservation and efficiency in homes, businesses, schools, and other infrastructure to reduce energy use and criteria pollutant and greenhouse gas emissions.

Policy HE-G.11: Renewable energy. Encourage renewable energy, such as solar and wind turbines, on commercial, industrial, and residential buildings.

Policy HE-G.12: Energy technologies. Support regional and local initiatives that promote integrated building systems, distributed generation, demand response programs, smart grid infrastructure, energy storage and backup, and electric transportation infrastructure.

3.8.3 Environmental Setting

3.8.3.1 U.S. Emissions
In 2018, the U.S. emitted about 6,677 MMTCO2e, with 75.4 percent of those emissions coming from fossil fuel combustion. Of the major sectors nationwide, transportation accounts for the highest amount of GHG emissions (approximately 28 percent), followed by electricity (27 percent), industry (22 percent), commercial and residential buildings (12 percent), and agriculture

3. Environmental Setting, Impacts, and Mitigation Measures

3.8 Greenhouse Gas Emissions
Sargent Quarry 3.8-6 ESA / D201901577.01
Draft EIR July 2022
(10 percent). Between 1990 and 2018, total U.S. GHG emissions rose by 6 percent, but emissions have generally decreased since peaking in 2005. Since 1990, U.S. emissions have increased at an average annual rate of 0.2 percent (USEPA 2020).

3.8.3.2 California Greenhouse Gas Emissions Inventory
CARB compiles GHG inventories for the state. Based on the 2019 GHG inventory data (i.e., the latest year for which data are available from CARB), California emitted 418.2 MMTCO2e, including emissions resulting from imported electrical power (CARB 2021a).

California has experienced both population and economic growth in the last 20 years, but GHG emissions have actually declined. Between 1990 and 2020, the population of California grew by approximately 10 million (from 29.8 to 39.8 million) (CDF 2020a). This represents an increase of approximately 34 percent from 1990 population levels. In addition, the California economy, measured as gross state product, grew from $773 billion in 1990 to $3.14 trillion in 2019, representing an increase of approximately 306 percent (more than three times the 1990 gross state product) in today’s dollars (CDF 2020b). Despite this growth, CARB’s 2019 statewide inventory indicated that California’s net GHG emissions in 2019 were below 1990 levels (i.e., 431 MMTCO2e), which is the 2020 GHG reduction target codified pursuant to AB 32.

Table 3.8-1 identifies and quantifies statewide anthropogenic GHG emissions and nonanthropogenic sinks (e.g., carbon sequestration due to forest growth) in 1990 and 2019. As shown in the table, the transportation sector is the largest contributor to statewide GHG emissions at approximately 40 percent in 2019.

TABLE 3.8-1

STATE OF CALIFORNIA GREENHOUSE GAS EMISSIONS
Category
Total 1990
Emissions
Using IPCC SAR
(MMTCO2e)
Percent of
Total 1990
Emissions
Total 2019
Emissions
Using IPCC AR4
(MMTCO2e)
Percent of
Total 2019
Emissions
Transportation 150.7 35% 166.1 40%
Electric Power 110.6 26% 58.8 14%
Commercial and Residential 44.1 10% 43.8 10%
Industrial 103.0 24% 88.2 21%
Recycling and Wastea — — 8.9 2%
High GWP/Non-Specifiedb 1.3 <1% 20.6 5%
Agriculture/Forestry 23.6 6% 31.8 8%
Forestry Sinks -6.7 -2% —c —
Net Total (IPCC SAR) 426.6 100%e — —
Net Total (IPCC AR4)d 431 100%e 418.2 100%
NOTES:

AR4 = Fourth Assessment Report; GWP = global warming potential; IPCC = Intergovernmental Panel on Climate Change; MMTCO2e = million metric tons of carbon dioxide equivalents; SAR = Second Assessment Report a. Included in other categories for the 1990 emissions inventory. b. High GWP gases are not specifically called out in the 1990 emissions inventory. c. Revised methods under development (not reported for 2019). d. CARB revised the state’s 1990-level greenhouse gas (GHG) emissions using GWPs from the IPCC AR4. e. Total of individual percentages may not add up to 100% due to rounding.

SOURCES: CARB 2021a; CARB 2020.

3. Environmental Setting, Impacts, and Mitigation Measures

3.8 Greenhouse Gas Emissions
Sargent Quarry 3.8-7 ESA / D201901577.01
Draft EIR July 2022

3.8.3.3 Bay Area GHG Emissions
The BAAQMD 2017 Clean Air Plan presents GHG inventory data for the Bay Area compiled by BAAQMD. Table 3.8-2 shows the Bay Area GHG inventory by source category, organized according to the economic sectors used in the AB 32 Scoping Plan Update. The four largest sectors—transportation, stationary sources, energy, and buildings— collectively account for 91 percent of the total inventory (BAAQMD 2017b).

TABLE 3.8-2
2015 BAY AREA GHG EMISSIONS (CO2E PER YEAR)
Source Category Total Emissions by Source (CO2e)
Transportation 35,420,000
On-road 30,750,000
Off-road 4,670,000
Electricity/Co-Generation 12,240,000
Co-generation 5,880,000
Electricity generation 5,080,000
Electricity imports 1,280,000
Buildings 9,270,000
Residential fuel usage 5,450,000
Commercial fuel usage 3,820,000
Stationary Sources 22,360,000
Oil refineries 15,680,000
Natural gas combustion 4,980,000
Natural gas distribution* 460,000
Cement manufacturing 990,000
Fugitive and process emissions* 250,000
Waste Management 2,300,000
Landfills* 1,850,000
Composting/POTWs* 450,000
Fluorinated Gases 3,560,000
HFCs and PFCs (commercial, industrial, and transportation)* 3,470,000 SF6 (electricity production and semiconductor manufacturing)* 90,000 Agriculture 1,390,000
Animal waste* 760,000
Soil management 280,000
Agricultural equipment 230,000
Biomass burning 120,000
TOTAL EMISSIONS (CO2e) 86,540,000
NOTES:
* Significant source of super-GHGs.

POTWs = treatment of water and wastewater at publicly owned treatment works.

HFCs = hydrofluorocarbons.

PFCs = perfluorocarbons.

SOURCE: BAAQMD 2017b.

3. Environmental Setting, Impacts, and Mitigation Measures

3.8 Greenhouse Gas Emissions
Sargent Quarry 3.8-8 ESA / D201901577.01
Draft EIR July 2022

3.8.3.4 Project Site GHG Emissions
The majority of Sargent Ranch is undeveloped, and there are limited GHG-emitting activities at the Project site associated with cattle ranching (e.g., CH4). As shown in Table 3.8-2, agricultural activities in the Bay Area region represent only 1.6 percent of total GHG emissions, and the cattle operation at the Project site would produce only a small portion of the overall agricultural emissions. For the purposes of a conservative analysis, it is assumed that the existing cattle ranching activities at the site would be moved to another area at Sargent Ranch, and therefore the associated emissions are not considered to be baseline emissions for the Project.

3.8.4 Impact Evaluation

3.8.4.1 Approach to the Analysis
The GHG assessment evaluates proposed mining and processing operations based on the quantity of processed aggregate proposed be exported from the quarry, processing equipment and processing rates, off-road mobile equipment for use in mining and processing, the number and types of quarry vehicles, and the operation schedule.

GHG emissions associated with the Project were calculated consistent with the methods identified for calculation of the air pollutants described in Section 3.3, Air Quality, using the CalEEMod, EMFAC2021, and OFFROAD Orion models. The following sources of GHG emissions were identified as part of the Project:
• On-site operation of mobile quarry mining equipment (bulldozers, excavators, loaders, scrapers); • On-site vehicle travel (haul trucks);
• On-site operation of processing equipment (screens, washers, and conveyors); • On-site emergency generator;
• Off-site vehicle travel (rail and haul truck transport and worker traffic); and • Electricity usage, including on-site rock processing equipment.

For the Project, it is conservatively assumed that the proposed maximum throughput of 1,860,000 tons of sand and aggregate materials per year could be reached by 2024.1 Therefore, to determine the significance of the increase in GHG emissions, the projected GHG emissions for 2024 are compared to the significance threshold.

Construction and operational activities were calculated separately. For the construction period, exhaust emissions were calculated from construction-related equipment and vehicles. The Project’s total short-term construction emissions were amortized over the 30-year mining term to annualize the emissions. The emergency generator would be located on site to provide back-up power in the event of an electrical outage. No other stationary sources of combustion emissions are proposed. 1 Emissions modeling was conducted assuming construction in 2022 and operations starting in 2023. This results in a conservative estimate of emissions, because emission rates decrease with future years due to improvements in engine and fuel technology plus retirement of older, dirtier engines from the fleet.

3. Environmental Setting, Impacts, and Mitigation Measures

3.8 Greenhouse Gas Emissions
Sargent Quarry 3.8-9 ESA / D201901577.01
Draft EIR July 2022
Vehicle Travel and Equipment Exhaust Emissions
GHG emissions from vehicle travel, both on- and off-site, along with equipment operation were computed using the same modeling techniques as conducted to estimate the criteria air pollutants.

This methodology is described in detail under Impact 3.3-1 in Section 3.3, Air Quality.

Indirect Emissions from Electricity Usage
The processing plant and conveyoer belts would use electric power to operate, so they would not directly emit GHG. The quarry processing facility would include numerous fixed equipment that would be powered by electricity such as washing, separation, and classification equipment, and screens, conveyors, and stacking conveyors. Electricity also would be used to power water pumps and to support the office. Operation of the quarry would require 1,250 megawatt-hours per year (Illingworth and Rodkin, Inc. 2021).

Indirect emissions of CO2e would occur at the power plant(s) that would generate the electricity that would be consumed by the Project. Silicon Valley Clean Energy (SVCE) is the official electricity provider for Santa Clara County. SVCE purchases carbon-free electricity and partners with PG&E to deliver this electricity over existing power lines that they maintain. SVCE provides nearly 100-percent carbon-free energy (CAPCOA 2021), so CO2e emissions associated with electricity for the project operations would be negligible.

Significance Thresholds
On April 20, 2022, the BAAQMD adopted new CEQA Thresholds for Evaluating the Significance of Climate Impacts from Land Use Projects and Plans (BAAQMD 2022a). The revised CEQA thresholds are designed for “land use development” projects based on what will be required of such projects to achieve California’s long-term climate goal of carbon neutrality by 2045. The BAAQMD found that GHG emissions associated with new land use development projects would be considered to result in less-than-significant impacts if they incorporate design elements such as restricting natural gas usage and the wasteful, inefficient, or unnecessary energy usage at buildings; achieving VMT reductions for residential, office, and retail projects: and compliance with state off-street electric vehicle requirements (BAAQMD 2022b). These significance thresholds are not directly applicable to industrial quarry projects, such as the Project, and are therefore not used in this analysis.

The BAAQMD CEQA Air Quality Guidelines (BAAQMD 2017a) identifies GHG significance thresholds for operation of stationary source projects and for operation of land use development projects that do not include stationary sources. The Project processing plant and generator would be subject to BAAQMD permitting requirements for stationary sources. The threshold for stationary sources is 10,000 metric tons CO2e per year, but this threshold is not applicable because the Project would include both stationary and mobile sources of GHG emissions. Following are the three thresholds of significance options for GHG emissions of land use development projects:
1) compliance with a qualified GHG reduction strategy; 2) 1,100 metric tons CO2e per year; or 3) 4.6 metric tons CO2e per service population (residents + employees) per year.

3. Environmental Setting, Impacts, and Mitigation Measures

3.8 Greenhouse Gas Emissions
Sargent Quarry 3.8-10 ESA / D201901577.01
Draft EIR July 2022
The first threshold is not applicable because the County has not adopted a qualified GHG reduction strategy. Similar to the BAAQMD’s new significance thresholds, the second and third thresholds of significance, which were primarily developed by the BAAQMD for residential, office, or mixed-use projects in urban infill locations, are not directly applicable to the Project because it would be an industrial use located in a rural unincorporated area. In addition, these significance thresholds were designed for the BAAQMD to meet the AB 32 goal of reducing GHG emissions to 1990 levels by 2020, and BAAQMD has not updated its significance thresholds to be consistent with the more recently adopted SB 32 target of reducing statewide GHG emissions to 40 percent below 1990 levels by 2030.

In the absence of an updated mass emissions threshold for industrial uses in rural areas that is applicable to the Project and consistent with the targets established by SB 32, this EIR in Impact 3.8-1 considers any net increase in Project-related GHG emissions to be significant.

3.8.4.2 Significance Criteria
The Project would result in a significant impact related to GHG emissions if it would:
a) Generate GHG emissions, either directly or indirectly, that may have a significant impact on the environment; or
b) Conflict with an applicable plan, policy or regulation adopted for the purpose of reducing the emissions of GHGs.

3.8.4.3 Project Impacts
Impact 3.8-1: The Project would generate greenhouse gas emissions directly and indirectly, contributing to global climate change. (Less than Significant with Mitigation) This impact addresses Significance Criterion (a).

All Components
Table 3.8-3 reports the estimated amortized construction GHG emissions and operations emissions for the Project assuming the first year of maximum quarry throughput operations. The Project would cause an increase in GHG emissions of 7,408 metric tons CO2e annually. These emissions include construction emissions amortized over the proposed 30-year mining period. Emissions would decrease in subsequent years due to a reduction in tailpipe emissions from on-road mobile sources in the future, and because not every year would be a maximum throughput year.

The majority, or 65 percent, of the emissions would be associated with off-site truck travel, followed by 30 percent that would be associated with on-site off-road equipment. The GHG estimates are based on the emission calculations provided in Appendix D. The resulting emissions are greater than the significance threshold value of zero, so the impact would be significant.

3. Environmental Setting, Impacts, and Mitigation Measures

3.8 Greenhouse Gas Emissions
Sargent Quarry 3.8-11 ESA / D201901577.01
Draft EIR July 2022
TABLE 3.8-3

PROJECT ANNUAL GHG EMISSIONS
Emission Source
2024 CO2e
(tons/year)
Amortized construction emissions 8
Off-road equipment exhaust (dozers, loader, graders, and scrapers) 2,266 On-site quarry vehicle exhaust (service trucks, pickup trucks, and water trucks) 116 Rail emissions 288
Off-site vehicle emissions (haul truck and employee vehicles) 4,730 Electricity consumption1 ~1
Total2 7,408
Threshold No net increase
Above Threshold Yes
NOTES:

1. Based on assumption that the Project would use electricity that is nearly carbon-free supplied by SVCE.

2. Numbers may not add exactly due to rounding.

SOURCE: Illingworth and Rodkin, Inc. 2021.

Mitigation Measure 3.8-1a: Prior to the commencement of the construction activities, the Applicant shall purchase offset credits in the amount of 7,408 metric tons CO2e. This amount represents amortized construction emissions plus estimated first year operational emissions. The Applicant shall provide verification to the County that carbon offset credits have been purchased.

The Applicant shall prioritize offsets within Santa Clara County, BAAQMD boundaries, the rest of California, and from other states with offset laws at least as strict as California’s, in order of preference. The carbon offset credits shall be real, permanent, quantifiable, verifiable, additional, and enforceable, as defined by 17 CCR 95802. Offset protocols must also be consistent with CARB requirements under 17 CR 95972. Carbon offsets must meet these requirements and be purchased from offset programs verified by a recognized third-party registry such as the American Carbon Registry, Verra, or Climate Action Reserve. For each subsequent year of Project operations, the Applicant shall choose one of the following options.
• Option 1: The Applicant shall continue to make the offset payment each subsequent year in the complete amount of 7,408 metric tons CO2e.
• Option 2: The Applicant shall purchase offset credits in the amount of 7,408 metric tons CO2e minus the difference between 7,408 metric tons and the actual CO2e emissions that the project generated in the prior year. Based on actual Project construction and/or subsequent year operational activities that resulted in GHG emissions, the Applicant shall calculate annual GHG emissions, including consideration of any measures that have been taken to reduce project GHG emissions, and provide emissions estimates to the County for review and approval.

Within 60 days of County approval of the estimated emissions, the Applicant shall provide verification to the County that carbon offset credits have been purchased for the amount identified by the County-approved emissions estimates.

3. Environmental Setting, Impacts, and Mitigation Measures

3.8 Greenhouse Gas Emissions
Sargent Quarry 3.8-12 ESA / D201901577.01
Draft EIR July 2022
Mitigation Measure 3.8-1b: For construction and operational off-road equipment, the Applicant shall replace diesel and gasoline-powered vehicles with electric or other low or zero-GHG emissions equipment as feasible, based on availability of the technology and whether the cost would be prohibitive. In addition, biodiesel or renewable diesel shall replace traditional petroleum-based diesel to fuel off-road equipment where feasible, based on availability of the technology and whether the cost would be prohibitive. Any resulting changes to the Project fleet or fuel type shall be reflected in the calculations of GHG emissions for Option #2 of Mitigation Measure 3.8-1a. Prior to the commencement of construction activities, and every five years afterward, the Applicant shall provide the County with a report for County review and approval describing the feasibility of using low carbon-emitting equipment and fuels for the Project.

Mitigation Measure 3.8-1c: If and when electric haul trucks are used for product hauling associated with the Project, the Applicant shall install conduit and EV charging stations at locations where trucks will be parked or idling. The Applicant shall notify the County when installation of conduit and EV charging stations is completed, following which the County shall verify installation. Any resulting changes to the Project fleet shall be reflected in the calculations of GHG emissions for Options #2 in Mitigation Measure 3.8-1a. This mitigation measure will also reduce future NOx emissions from trips to the site.

Significance after Mitigation: Less than significant.

Implementation of Mitigation Measures 3.8-1a through 3.8-1c would reduce the significant impact to a less-than-significant level. Specifically, pursuant to Mitigation Measure 3.8-1a, the Applicant would be required to purchase carbon credits to offset GHG emissions associated with the Project to achieve the net zero significance threshold, taking into account the implementation of Mitigation Measures 3.8-1b and 3.8-1c.

Impact 3.8-2: The Project could conflict with an applicable plan, policy, or regulation adopted for the purpose of reducing the emissions of GHGs. (Less than Significant with Mitigation) This impact addresses Significance Criterion (b).

All Components
The Project would emit GHGs in the amount shown in Table 3.8-3. Because it would increase GHG emissions, the Project would impede the state’s efforts to achieve the GHG reductions needed to comply with the SB 32, the CARB 2017 GHG Scoping Plan, and Executive Order B-55-18. As such, the impact would be significant.

Mitigation: Implement Mitigation Measures 3.8-1a through 3.8-1d.

Significance after Mitigation: Less than significant.

Mitigation Measures 3.8-1a through 3.8-1d would reduce the GHG emissions associated with the Project to zero. This would not conflict with the SB 32 reduction goal for 2030, CARB 2017 GHG Scoping Plan, or Executive Order B-55-18. Therefore, as mitigated, the Project would not conflict with plans, policies, or regulations to reduce GHG emissions.
_________________________

3. Environmental Setting, Impacts, and Mitigation Measures

3.8 Greenhouse Gas Emissions
Sargent Quarry 3.8-13 ESA / D201901577.01
Draft EIR July 2022

3.8.4.4 Cumulative Analysis
Although the geographical extent of GHG emissions and climate change is global, as climate change is caused by GHGs emitted into the atmosphere around the world from a variety of sources, the analysis in this EIR focuses on GHG emissions within California to evaluate the significance of the Project’s contribution. In the CEQA context, because an individual project could not alter the climate, a project’s GHG emissions are inherently cumulative because they contribute to significant statewide cumulative GHG emissions. Because they exceed significance thresholds, Impacts 3.8-1 and 3.8-2 are also cumulatively considerable, but would be reduced to less-than—cumulatively considerable and less-than-significant levels by Mitigation Measures 3.8-1a through 3.8-1d. _________________________

3.8.5 References
Bay Area Air Quality Management District (BAAQMD). 2017a. CEQA Air Quality Guidelines.

Available at https://www.baaqmd.gov/~/media/files/planning-and-research/ceqa/ ceqa_guidelines_may2017-pdf.pdf?la=en, accessed August 2021.

BAAQMD. 2017b. Spare the Air – Cool the Climate: A Blueprint for Clean Air and Climate Protection in the Bay Area. Available at https://www.baaqmd.gov/plans-and-climate/airquality-plans/current-plans. Accessed August 2021.

BAAQMD. 2022a. CEQA Thresholds and Guidelines Update webpage. Available at https://www.baaqmd.gov/plans-and-climate/california-environmental-quality-actceqa/updated-ceqa-guidelines. Accessed June 24, 2022.

BAAQMD. 2022b. Justification Report: CEQA Thresholds for Evaluating the Significance of Climate Impacts from Land Use Projects and Plans. Available at https://www.baaqmd.gov/plans-and-climate/california-environmental-quality-actceqa/updated-ceqa-guidelines. Accessed June 24, 2022.

California Air Pollution Control Officers Association (CAPCOA). 2021. Handbook for Analyzing Greenhouse Gas Emission Reductions, Assessing Climate Vulnerabilities, and Advancing Health and Equity. Public Draft, August. Available online at: Handbook Public Draft_2021- Aug.pdf (airquality.org). Accessed September 2021.

California Air Resources Board (CARB). 2008. Climate Change Scoping Plan: A Framework for Change, 2008, Appendix F. Available at https://ww3.arb.ca.gov/cc/scopingplan/document/ adopted_scoping_plan.pdf. Accessed October 20, 2021.

CARB. 2017. California’s 2017 Climate Change Scoping Plan: The Strategy for Achieving California’s 2030 Greenhouse Gas Target, 2017. Available at https://ww3.arb.ca.gov/cc/ scopingplan/scoping_plan_2017.pdf. Accessed October 20, 2021.

CARB. 2018. SB 375 Regional Greenhouse Gas Emissions Reduction Targets. Available at https:// ww2.arb.ca.gov/sites/default/files/2020-06/SB375_Final_Targets_2018.pdf. Accessed October 21, 2021.

3. Environmental Setting, Impacts, and Mitigation Measures

3.8 Greenhouse Gas Emissions
Sargent Quarry 3.8-14 ESA / D201901577.01
Draft EIR July 2022
CARB. 2020. California Greenhouse Gas Emissions Inventory: Data used to generate figures in the California Greenhouse Gas Emissions for 2000 to 2018- Trends of Emissions and Other Indicators report. Available online at https://ww3.arb.ca.gov/cc/inventory/pubs/reports/ 2000_2018/2000_2018_ghg_inventory_trends_figures.xlsx. Accessed January 29, 2021.

CARB. 2021a. California Greenhouse Gas Emissions for 2000-2019, Trends of Emissions and Other Indicators, Figure 3. Available at https://ww3.arb.ca.gov/cc/inventory/pubs/reports/ 2000_2019/ghg_inventory_trends_00-19.pdf. Accessed August 2021.

CARB. 2021b. California’s GHG Vehicle Emission Standards under Assembly Bill 1493 of 2002 (Pavley). Available online at: https://ww2.arb.ca.gov/californias-greenhouse-gas-vehicleemission-standards-under-assembly-bill-1493-2002-pavley. Accessed August 2021.

California Department of Finance (CDF). 2020a. E-4 Historical Population Estimates for Cities, Counties, and the State and E-5 Population and Housing Estimates for Cities, Counties, and the State, 2020. Available at http://www.dof.ca.gov/Forecasting/Demographics/Estimates/.

Accessed August 2021.

CDF. 2020b. Gross State Product, 2020. Available at http://www.dof.ca.gov/Forecasting/ Economics/Indicators/Gross_State_Product/. Accessed August 2021. Amounts are based on current dollars as of the date of the report (April 2020).

California Governor’s Office of Planning and Research, Scripps Institution of Oceanography, CEC, California Public Utilities Commission (OPR). 2018. California’s Fourth Climate Change Assessment: Statewide Summary Report, Publication no. SUMCCCA4-2018-013, August 2018. Available at https://www.energy.ca.gov/sites/default/files/2019-11/ Statewide_Reports-SUM-CCCA4-2018-013_Statewide_Summary_Report_ADA.pdf.

Accessed October 22, 2021.

County of Santa Clara. 2015. Santa Clara County General Plan Health Element. August 25, 2015.

Federal Register. 2021. National Highway Traffic Safety Administration (NHTSA), Department of Transportation (DOT), Notice of Proposed Rulemaking. May 12. Available at https:// www.federalregister.gov/documents/2021/05/12/2021-08758/corporate-average-fueleconomy-cafe-preemption. Accessed October 27, 2021.

Illingworth & Rodkin, Inc. 2021. Sargent Quarry Air Quality and Greenhouse Gas Assessment Santa Clara County, CA. Updated August 2021.

Metropolitan Transportation Commission and Association of Bay Area Governments. 2021. Final Plan Bay Area 2050. Available at https://www.planbayarea.org/finalplan2050. Accessed October 21, 2021.

U.S. Environmental Protection Agency (USEPA). 2009. Federal Register, 40 CFR Parts 86, 87, 89 et al., Mandatory Reporting of Greenhouse Gases; Final Rule, page 56264, October 30, 2009.

USEPA. 2021. Data Highlights Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990– 2018, April 13, 2020. Available at https://www.epa.gov/ghgemissions/inventory-usgreenhouse-gas-emissions-and-sinks-fast-facts-and-data-highlights. Accessed August 2021.

3. Environmental Setting, Impacts, and Mitigation Measures

3.9 Hazards and Hazardous Materials
Sargent Quarry 3.9-1 ESA / D201901577.01
Draft EIR July 2022

3.9 Hazards and Hazardous Materials

3.9.1 Introduction
This section identifies and evaluates the hazards and hazardous materials impacts that could result from implementation of the Project. Hazards evaluated in this section include potential soil contamination due to historic pesticide use, hazardous materials transportation, storage and use during construction and operation of the Project. Hazardous materials are substances or materials that could adversely affect the safety of the public, handlers, carriers, or environmental media (such as air, soils, or water) and can include materials used in manufacturing, mining, construction and related activities, as well as common office products such as cleaning products or insecticides.

Hazardous waste is waste (typically a hazardous material that is discarded or a by-product of manufacturing processes) that is potentially harmful to human health or the environment, and can be liquid, solid, gas, or sludge.

A Phase I Environmental Site Assessment was prepared for the Project site (Appendix H). Issues related to wildfire hazards are addressed in Section 3.15, Wildfire.

3.9.2 Regulatory Setting

3.9.2.1 Federal
Hazardous Materials Management
The primary federal agencies with responsibility for hazardous materials management include the U.S. Environmental Protection Agency (USEPA), U.S. Department of Labor Occupational Safety and Health Administration (OSHA), and the U.S. Department of Transportation (USDOT). State and local agencies often have either parallel or more stringent regulations than these federal agencies.

In most cases, state law mirrors or overlaps federal law and enforcement of these laws is the responsibility of the state or of a local agency to which enforcement powers are delegated.

Hazardous Materials Transportation
The USDOT regulates hazardous materials transportation on all interstate roads pursuant to its authority under the Hazardous Materials Transportation Uniform Safety Act (49 U.S.C.

Section 5101 et seq.). The purpose of the Act is to “protect against the risks to life, property, and the environment that are inherent in the transportation of hazardous material in intrastate, interstate, and foreign commerce” (49 U.S.C. Section 5101). Within California, the state agencies with primary responsibility for enforcing federal and state regulations and for responding to transportation emergencies are the California Highway Patrol (CHP) and California Department of Transportation (Caltrans). Together, federal and state agencies determine driver-training requirements, load labeling procedures, and container specifications. Although special requirements apply to transporting hazardous materials, requirements for transporting hazardous waste are more stringent, and hazardous waste haulers must be licensed to transport hazardous waste on public roads.

3. Environmental Setting, Impacts, and Mitigation Measures

3.9 Hazards and Hazardous Materials
Sargent Quarry 3.9-2 ESA / D201901577.01
Draft EIR July 2022
Clean Air Act
Regulations under the Clean Air Act are designed to prevent accidental releases of hazardous materials. The regulations require facilities that store minimum quantities (called threshold quantities) or greater of listed regulated substances to develop a Risk Management Plan, including hazard assessments and response programs to prevent accidental releases of listed chemicals.

Oil Pollution Prevention
Part 112 of Subchapter D of Chapter I of Title 40 of the Federal Code of Regulations (40 CFR Section 112) establishes procedures, methods, equipment, and other requirements to prevent discharges from non-transportation-related onshore and offshore facilities into or upon the navigable waters of the United States or that may affect natural resources belonging to, appertaining to, or under the exclusive management authority of the United States. These regulations require facilities with a single tank or cumulative aboveground storage capacities of 1,320 gallons or greater of petroleum to prepare and implement a Spill Prevention, Control, and Countermeasure (SPCC) Plan (40 CFR Section 112.1). The purpose of an SPCC Plan is to form a comprehensive federal/state spill prevention program that minimizes the potential for discharges. The SPCC Plan must address all relevant spill prevention, control, and countermeasures necessary at the specific facility for which the SPCC Plan is written.

Comprehensive Environmental Response and Liability Act and Superfund Amendments and Reauthorization Act
The Superfund Amendments and Reauthorization Act (SARA) amends the Comprehensive Environmental Response and Liability Act (CERCLA) and governs hazardous substances. The applicable part of SARA for the Project is Title III, otherwise known as the Emergency Planning and Community Right-To-Know Act of 1986 (EPCRA). EPCRA establishes requirements for federal, state, and local governments, as well as Indian Tribes and industry members regarding emergency planning and reporting on hazardous and toxic chemicals (USEPA 2021). Key sections of the law include:

Section 304: Requires immediate notification to the local emergency planning committee (LEPC) and the state emergency response commission (SERC) when a hazardous material is released in excess of its reportable quantity (RQ). If a CERCLA-listed hazardous substance RQ is released, notification must also be given to the National Response Center in Washington, D.C. (RQs are listed in 40 CFR Part 302, Table 302.4). These notifications are in addition to notifications given to the local emergency response team or fire personnel.

Section 311: Requires that either material safety data sheets (MSDSs) for all hazardous materials or a list of all hazardous materials be submitted to the SERC, LEPC, and local fire department.

Toxic Substances Control Act, Resource Conservation and Recovery Act The Federal Toxic Substances Control Act of 1976 and the Resource Conservation and Recovery Act of 1976 (RCRA) established a program administered by the USEPA for the regulation of the generation, transportation, treatment, storage, and disposal of hazardous waste. RCRA was

3. Environmental Setting, Impacts, and Mitigation Measures

3.9 Hazards and Hazardous Materials
Sargent Quarry 3.9-3 ESA / D201901577.01
Draft EIR July 2022
amended in 1984 by the Hazardous and Solid Waste Amendments, which affirmed and extended the “cradle to grave” system of regulating hazardous wastes.

Federal Insecticide, Fungicide, and Rodenticide Act
The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), amended in 1996, authorizes the USEPA to register or license pesticides (including herbicides) for use in the United States.

Pesticides must be registered both with the USEPA and the state before distribution. If any pesticides are used on the Project site, their use must comply with applicable federal requirements.

Under the FIFRA, the California Department of Pesticide Regulation (CDPR) is vested with primary responsibility to enforce pesticide laws and regulations in California. Pesticide rules are found in different sections of California codes and regulations, including the Food and Agriculture Code, Business and Professions Code, Health and Safety Code, and Labor Code. In general, the CDPR regulates pesticide sales and use statewide, while local use is enforced through the County Agricultural Commissioners. The County’s Integrated Pest Management Division monitors pesticide applications to ensure they are performed in a safe and effective manner and that worker safety requirements are followed; inspects application equipment, pesticide storage sites, employee training documents and business pesticide use records; and investigates complaints and pesticiderelated illnesses.

Occupational Safety
OSHA is responsible for assuring worker safety in the handling and use of chemicals in the workplace. The federal regulations pertaining to worker safety are contained in Title 29 of the Code of Federal Regulations, as authorized in the Occupational Safety and Health Act of 1970. They provide standards for safe workplaces and work practices, including standards relating to hazardous materials handling. At sites known or suspected to have soil or groundwater contamination, construction workers must receive training in hazardous materials operations and a site health and safety plan must be prepared. The health and safety plan establishes policies and procedures to protect workers and the public from exposure to potential hazards at the contaminated site.

3.9.2.2 State
Unified Hazardous Waste and Hazardous Materials Management Regulatory Program
In January 1996, the California Environmental Protection Agency (Cal EPA) adopted regulations implementing a Unified Hazardous Waste and Hazardous Materials Management Regulatory Program (Unified Program, Health & Safety Code Section 25404 et seq.) The program has six elements: hazardous waste generators and hazardous waste on-site treatment; underground storage tanks; aboveground storage tanks; hazardous materials release response plans and inventories; risk management and prevention programs; and Unified Fire Code hazardous materials management plans and inventories. The plan is implemented at the local level. The Certified Unified Program Agency (CUPA) is the local agency that is responsible for the implementation of the Unified Program. The County’s Hazardous Materials Compliance Division is the designated CUPA for all businesses (County of Santa Clara 2021a).

3. Environmental Setting, Impacts, and Mitigation Measures

3.9 Hazards and Hazardous Materials
Sargent Quarry 3.9-4 ESA / D201901577.01
Draft EIR July 2022
Hazardous Materials Management
The California Hazardous Materials Release Response Plans and Inventory Law (Business Plan Act, Health and Safety Code Section 25500 et seq.) requires any business that handles hazardous materials at or above specified thresholds to prepare a hazardous materials business plan (HMBP). The HMBP must include the following:
• Details, including floor plans, of the facility and business conducted at the site • An inventory of hazardous materials that are handled or stored on site • An emergency response plan
• A safety and emergency response training program for new employees with annual refresher courses
The primary purpose of the HMBP requirements is to provide basic information needed by first responders to prevent or mitigate damage to the public health and safety and to the environment from a release or threatened release of a hazardous material (Cal OES 2014).

Hazardous Waste Handling
The Department of Toxic Substances Control (DTSC) regulates the generation, transportation, treatment, storage, and disposal of hazardous waste. State and federal laws require detailed planning to ensure that hazardous materials are properly handled, used, stored, and disposed of, and, in the event that such materials are accidentally released, to prevent or to mitigate injury to health or the environment. Laws and regulations require hazardous materials users to store these materials appropriately and to train employees to manage them safely.

Individual states may implement their own hazardous waste programs in lieu of RCRA, as long as the state program is at least as stringent as federal RCRA requirements. In California, the DTSC regulates the generation, transportation, treatment, storage, and disposal of hazardous waste. The hazardous waste regulations establish criteria for identifying, packaging, and labeling hazardous wastes; prescribe management of hazardous waste; establish permit requirements for hazardous waste treatment, storage, disposal, and transportation; and identify hazardous wastes that cannot be disposed of in landfills. These regulations list more than 800 materials that may be hazardous and establish criteria for identifying, packaging, and disposing of such waste. The California Hazardous Waste Control Law is codified at Health and Safety Code Section 25100 et seq.

Occupational Safety
The California Department of Industrial Relations Division of Occupational Safety and Health (Cal/OSHA) assumes primary responsibility for developing and enforcing workplace safety regulations in California. Because California has a federally approved OSHA program, it is required to adopt regulations that are at least as stringent as those found in Title 29 of the Code of Federal Regulations.

Cal/OSHA regulations concerning the use of hazardous materials in the workplace require employee safety training, safety equipment, accident and illness prevention programs, hazardous

3. Environmental Setting, Impacts, and Mitigation Measures

3.9 Hazards and Hazardous Materials
Sargent Quarry 3.9-5 ESA / D201901577.01
Draft EIR July 2022
substance exposure warnings, and emergency action and fire prevention plan preparation. Cal/OSHA enforces hazard communication program regulations, which contain training and information requirements, including procedures for identifying and labeling hazardous substances, and communicating hazard information relating to hazardous substances and their handling. The hazard communication program also requires that safety data sheets (SDSs) be available to employees, and that employee information and training programs be documented. These regulations also require preparation of emergency action plans (escape and evacuation procedures, rescue and medical duties, alarm systems, and training in emergency evacuation).

Other State Regulations
The California Code of Regulations contains additional requirements that would apply to the Project, including:
• 8 Cal. Code Regs. Section 2700 et seq., High Voltage Electrical Safety Orders, which establish essential requirements and minimum standards for installation, operation, and maintenance of electrical equipment to provide practical safety and freedom from danger. • 22 Cal. Code Regs. Section 66273 Standards for Universal Waste Management, which regulate the management of universal wastes. These wastes are not fully regulated as hazardous waste in order to encourage their recycling. Batteries, electronic devices, mercurycontaining equipment, lamps, cathode ray tubes and tube glass, and aerosol cans are considered universal wastes in California. A person or business who generates universal waste is required to follow the Management Requirements for Universal Waste Handlers (22 Cal Code Regs. Sections 66273.30–66273.39), which include storage, spill protection, and disposal rules designed to minimize risk of harm to public health and the environment.

NPDES Construction General Permit and Industrial General Permit The Regional Water Quality Control Board (RWQCB) administers the stormwater permitting program in the Central Valley Region pursuant to authority delegated under the federal Clean Water Act’s National Pollutant Discharge Elimination System (NPDES) program. The required Stormwater Pollution Prevention Plan (SWPPP) (for construction) and Industrial SWPPP (for operation) include best management practices (BMPs) to minimize discharges of pollutants in stormwater runoff. The Construction General Permit and Industrial General Permit are described in detail in Section 3.10, Hydrology and Water Quality.

California Fire Code and California Building Code
The California Fire Code is contained within Title 24, Chapter 9 of the California Code of Regulations. Based on the International Fire Code, the California Fire Code is created by the California Buildings Standards Commission and regulates the use, handling, and storage requirements for hazardous materials at fixed facilities. Similar to the International Fire Code, the California Fire Code and the California Building Code (CBC) use a hazards classification system to determine the appropriate measures to incorporate to protect life and property.

3. Environmental Setting, Impacts, and Mitigation Measures

3.9 Hazards and Hazardous Materials
Sargent Quarry 3.9-6 ESA / D201901577.01
Draft EIR July 2022
Emergency Response
The Cal OES developed the State of California Emergency Plan (Cal OES 2017) to coordinate federal, state, local, and private agency emergency service providers’ response to natural or human-caused emergencies. Responding to hazardous materials incidents is one part of this plan.

The plan is administered by the Cal OES, which coordinates the responses of other agencies.

3.9.2.3 Local
Santa Clara County General Plan
The Santa Clara County General Plan Safety and Noise element contains the following planning strategies, policies, and implementation recommendations regarding hazardous materials and waste:

Strategy #1: Manage Hazardous Materials Safely and Efficiently - By adhering to adopted building and development standards (i.e., Uniform Fire Code, Uniform Building Code, Hazardous Materials Management Plan), the County and cities can ensure that new development is designed and maintained in a manner that will shield or distance people and the environment from dangerous materials and activities.

Policy C-HS 14: All feasible measures to safely and effectively manage hazardous materials and site hazardous materials treatment facilities should be used, including complying with all federal and state mandates.

Policy C-HS 15: To achieve a more effective, efficient and economical regulatory environment, all feasible means to simplify and coordinate locally implemented hazardous materials management regulations should be considered.

Implementation Recommendation C-HS(i) 6: Comply with all federal- and statemandated hazardous materials planning and regulatory measures.

Strategy #2: Ensure the Adequacy of Local Hazardous Waste Treatment Facilities - Where the use of hazardous materials is deemed necessary and appropriate, the County and cities should enforce reliance upon safe and cost-effective procedures. Through adoption and enforcement of the County Hazardous Waste Management Plan and other mandated hazardous materials programs, the County and cities can also ensure the safety, availability and adequacy of local hazardous waste treatment and disposal facilities.

Policy C-HS 15.2: The cities and Santa Clara County shall ensure that all relevant discretionary land use and development decisions: a. are consistent with the intent and provisions of the Countywide Hazardous Waste Management Plan (CHWMP), especially the facilities siting map and criteria, which identify potentially suitable areas for siting needed waste management facilities; and, b. do not unnecessarily limit the availability of sites suitable for potential hazardous waste management facilities, as identified in the CHWMP facilities siting criteria and map.

Santa Clara County Hazardous Materials Compliance Division The Hazardous Materials Compliance Division oversees the storage of hazardous materials per the County’s Hazardous Materials Storage Ordinance, which includes several provisions to ensure the protection of the public health and the environment. The Hazardous Materials

3. Environmental Setting, Impacts, and Mitigation Measures

3.9 Hazards and Hazardous Materials
Sargent Quarry 3.9-7 ESA / D201901577.01
Draft EIR July 2022
Compliance Division is the CUPA for the County and is responsible for administering the following six programs into a consolidated enforcement program:
• Hazardous Waste Generator Program
• Tiered Permitting Program
• Hazardous Materials Business Plan (HMBP)
• Aboveground Petroleum Storage Act (APSA) Program
• Underground Storage Tank Program (UST)
• California Accidental Release Program (CalARP)
Santa Clara County Operational Area Emergency Operations Plan The Santa Clara County Operational Area Emergency Operations Plan (EOP) is an all-hazards document describing the County’s Emergency Operations organization, compliance with relevant legal statutes, other guidelines, and critical components of the Emergency Response System. The EOP is activated during extraordinary emergency situations associated with large-scale disasters affecting Santa Clara County and is not intended to address specific emergency responses (County of Santa Clara 2008).

The EOP establishes the overall operational concepts associated with the management of incidents, emergencies, crises, disasters, and catastrophes at the County level. It is applicable to a wide variety of anticipated incident events including earthquake, wildland fires, floods, and public health issues and facilitates multiagency and multi-jurisdictional coordination during emergency operations. There are several separately published annexes that support this EOP.

These supporting annexes further describe the operational or functional response to particular threats and hazards and the basic considerations, actions, and responsibilities of specific emergency response and management disciplines or functions.

3.9.3 Environmental Setting

3.9.3.1 Hazardous Materials and Waste
Hazardous waste handlers and generators in the County include industries, businesses, public and private institutions, and residences. Agricultural land use can also involve the storage and handling of hazardous materials and wastes including for the application of pesticides and the storage and use of fuels. Gasoline stations and other facilities that use or store fuels, solvents, chemicals or other hazardous materials represent other potential sources of hazardous materials in rural areas. The presence of these potential sources of hazardous materials, if encountered, can result in adverse environmental and health effects depending on the extent of exposure.

Definition of Hazardous Materials
A hazardous material is defined as any material that, because of quantity, concentration, or physical or chemical characteristics, poses a significant present or potential hazard to human health and safety or to the environment if released into the workplace or the environment (Health and Safety

3. Environmental Setting, Impacts, and Mitigation Measures

3.9 Hazards and Hazardous Materials
Sargent Quarry 3.9-8 ESA / D201901577.01
Draft EIR July 2022
Code Section 25501(o)). The term “hazardous materials” refers to both hazardous substances and hazardous wastes. Under federal and state laws, any material, including wastes, may be considered hazardous if it is specifically listed by statute as such or if it is toxic (causes adverse human health effects), ignitable (has the ability to burn), corrosive (causes severe burns or damage to materials), or reactive (causes explosions or generates toxic gases).

In some cases, past industrial or commercial activities on a site have resulted in spills or leaks of hazardous materials or wastes to the subsurface, resulting in soil and/or groundwater contamination.

Depending on the type and concentrations of contamination, potential exposure can threaten public health if released from the soil, groundwater, or into the air. The four primary exposure pathways through which an individual can be exposed to a hazardous material or waste are inhalation, ingestion, bodily contact, and injection. Exposure can result from an accidental release of hazardous materials during transport, storage, or handling. Disturbance of contaminated subsurface soil during construction also can cause exposures to workers, the public, or the environment through excavating, stockpiling, handling, or transport of such soils.

Soil and Groundwater Contamination
In California, regulatory databases listing hazardous materials sites provided by numerous federal, state, and local agencies are consolidated in the “Cortese List” pursuant to Government Code Section 65962.5, effective in 1992. However, subsequent changes in web-based information availability since that time have made a consolidation of this list no longer necessary and the databases are maintained on an individual basis by the following responsible agencies:
• List of Hazardous Waste and Substances sites from Department of Toxic Substances Control (DTSC) EnviroStor database
• List of Leaking Underground Storage Tank Sites by County and Fiscal Year from the State Water Resources Control Board (SWRCB) GeoTracker database • List of solid waste disposal sites identified by SWRCB with waste constituents above hazardous waste levels outside the waste management unit • List of “active” Cease and Desist Order and Cleanup and Abatement Order from the SWRCB • List of hazardous waste facilities subject to corrective action pursuant to Section 25187.5 of the Health and Safety Code, identified by DTSC and listed on their EnviroStor database These five databases identify sites with suspected and confirmed releases of hazardous materials to the subsurface soil and/or groundwater. The SWRCB GeoTracker database includes leaking underground storage tanks (LUSTs), permitted underground storage tanks (USTs), Department of Defense sites, and Cleanup Program sites. The DTSC EnviroStor database includes federal and state response sites; voluntary, school, and military cleanups and corrective actions; and permitted sites.

The reporting and statuses of these sites change as identification, monitoring, and cleanup of hazardous materials sites progress. Typically, a listed site is considered no longer to be of concern once it has been demonstrated that existing site uses combined with the levels of identified contamination present no significant risk to human health or the environment and the case is closed by the overseeing agency.

3. Environmental Setting, Impacts, and Mitigation Measures

3.9 Hazards and Hazardous Materials
Sargent Quarry 3.9-9 ESA / D201901577.01
Draft EIR July 2022
According to a review of the GeoTracker database, the Project site is not included as an active LUST site or a Cleanup Program site, nor are there any open cases within 1 mile of the Project site (SWRCB 2021). The nearest LUST and cleanup sites are located just over 1 mile north and south of the Project site; both are closed cases. Accordingly, the Project site is unlikely to have been adversely affected by migration of hazardous materials through groundwater from these sites.

CalGEM indicates that there are several oil and gas wells located near the Project site with the closest well located approximately 400 feet away. These wells were drilled by the Sargent Oil Company and are plugged and abandoned (CalGEM 2021). The Phase I Environmental Site Assessment (included as Appendix H) recommends coordination of Project activities with the California Department of Conservation, Division of Oil, Gas, and Geothermal Resources.

Phase I Environmental Site Assessment
A Phase I Environmental Site Assessment was prepared for the Project site (Appendix H). The purpose of the investigation was to identify any known or suspected areas of hazardous materials or wastes that may be present beneath, on, or within proximity to the Project site. The Phase I Environmental Site Assessment identified recognized environmental conditions (RECs), including the abandoned oil and gas wells described above, and the potential for soil adjacent to structures that are painted with lead-containing paint to contain lead as a result of the weathering and/or peeling of painted surfaces. There is an existing ranch house on the north side of Tar Creek, near the Old Monterey Road undercrossing. This house would not be altered by the Project. The Phase I Environmental Site Assessment refers to a house that had been demolished, but it was located outside of the Project site. Soil near wood framed structures also can be impacted by pesticides historically used to control termites, and pesticides may also have been used at livestock management areas including the on-site corral area located at the northeast portion of the Project site. There is a potential that residual lead and pesticide concentrations could remain in on-site soil. The Phase I Environmental Site Assessment includes recommendations for several of the RECs identified; to the extent that these recommendations address conditions that could affect or be affected by the Project, this EIR considers and incorporates them as appropriate. Several recommendations address off-site conditions and are not included here.

3.9.4 Impact Evaluation

3.9.4.1 Approach to the Analysis
The impact analysis for hazards and hazardous materials involved reviewing the hazards databases described in Section 3.9.3, Environmental Setting, the Phase I Environmental Site Assessment (Appendix H), and the Sargent Quarry Mining and Reclamation Plan (Appendix B) to identify existing and potential Project-related sources of hazards and hazardous materials. The analysis also assessed the potential for accidental releases of existing or proposed hazardous materials into the environment.

3. Environmental Setting, Impacts, and Mitigation Measures

3.9 Hazards and Hazardous Materials
Sargent Quarry 3.9-10 ESA / D201901577.01
Draft EIR July 2022

3.9.4.2 Significance Criteria
A project would result in significant impacts related to hazards and hazardous materials if it would:
a) Create a significant hazard to the public or the environment through the routine transport, use, or disposal of hazardous materials;
b) Create a significant hazard to the public or the environment through reasonably foreseeable upset and accident conditions involving the release of hazardous materials into the environment;
c) Emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or waste within one-quarter mile of an existing or proposed school; d) Be located on a site which is included on a list of hazardous materials sites compiled pursuant to Government Code Section 65962.5 and, as a result, would it create a significant hazard to the public or the environment;
e) For a project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project result in a safety hazard or excessive noise for people residing or working in the project area; or f) Impair implementation of or physically interfere with an adopted emergency response plan or emergency evacuation plan.

The environmental checklist included in CEQA Guidelines Appendix G further suggests that a project would result in significant impacts related to hazards and hazardous materials if it would expose people or structures, either directly or indirectly, to a significant risk of loss, injury, or death involving wildland fires. Impacts relating to wildfire are addressed in Section 3.15, Wildfire.

Due to the nature of the Project, the following criteria are not analyzed in this section for the reasons described below:
• Emit hazardous emissions or handle hazardous substances or acutely hazardous materials, substances, or waste within 0.25 mile of an existing or proposed school. The Project is not located within 0.25 miles of an existing or proposed school. The closest schools are the Aromas-San Juan School located approximately 0.9 miles southeast, and Anzar High School located approximately 1.3 miles away. Under this criterion, there would be no impact. • Be located on a site which is included on a list of hazardous materials sites compiled pursuant to Government Code Section 65962.5 and, as a result, create a significant hazard to the public or the environment. The Project is not proposed on a site included on a list of hazardous materials sites pursuant to Government Code Section 65962.5. According to the Phase I Environmental Site Assessment prepared for the Project site (Appendix H) and a recent review of publicly available environmental databases, the Project site is not listed as a hazardous materials site (SWRCB 2021; DTSC 2021). Therefore, the Project would cause no impact with respect to this criterion.
• Be located within an airport land use plan or within 2 miles of a public airport or a public use airport, and so result in a safety hazard or excessive noise for people residing or

3. Environmental Setting, Impacts, and Mitigation Measures

3.9 Hazards and Hazardous Materials
Sargent Quarry 3.9-11 ESA / D201901577.01
Draft EIR July 2022
working in the project area. The Project would not be located within an airport land use plan and is located approximately 5 miles from the nearest private airport (the Frazier Lake Airport). Therefore, the Project is not part of any airport land use plan and would not interfere with airport operations or result in a safety hazard for people residing or working in the area:
no impact would result with respect to this criterion.
• Impair implementation of or physically interfere with an adopted emergency response plan or emergency evacuation plan. The Project would not impair implementation of or physically interfere with the County Emergency Operations Plan which was adopted by the County Board of Supervisors on March 18, 2008 (County of Santa Clara 2008). The Project site and surrounding areas are largely undeveloped and located entirely on private property that is not designated in the County’s Emergency Operations Plan for use in emergency response or evacuation. To facilitate truck access, an existing U.S. 101 on-ramp east of the Project site would be improved and would be built according to Caltrans specifications. In addition, the northern portion of Old Monterey Road within a County right-of-way, would be improved as needed with new pavement overlaid on the existing roadway. Although the Project would alter some existing road networks, these roads would not interfere with any identified evacuation route, restrict access for emergency response vehicles, or restrict access to critical facilities such as hospitals or fire stations. Consequently, the Project would cause no impact related to this criterion.

3.9.4.3 Project Impacts
Impact 3.9-1: The Project would routinely transport, use, and dispose of hazardous materials, which could pose a risk to human health and/or the environment. (Less than Significant)
This impact discussion corresponds to Significance Criteria (a) and (b) and focuses on the transport, use, and disposal of Project-related hazardous materials and the potential for accidental releases of those materials.

Construction
All Project Components
During construction, diesel and gasoline fuels and other hazardous materials such as such as hydraulic fluid, fuel, insulation oil, grease, lubricants, paints, solvents, and adhesives commonly associated with construction activities and equipment may be used and stored on site. Generally, the quantities of these hazardous materials would be relatively limited and handled in accordance with manufacturer’s guidelines. These materials would be stored and handled in a manner to prevent accidental release, consistent with the SPCC Plan and measures contained within the required SWPPP (Appendix I). For example, the Project’s SWPPP requires that such materials be stored within containers with secondary containment, such that spills from storage containers would be prevented from release into the environment. Further discussion of BMP requirements is provided in Section 3.10, Hydrology and Water Quality. SDSs for all applicable materials present at the site would be made readily available to on-site personnel. Any accidental spills would be contained and cleaned up immediately as specified in the SPCC Plan and the HMBP, which would ensure that any spills are rectified before they could become a hazard to the human health or the environment.

3. Environmental Setting, Impacts, and Mitigation Measures

3.9 Hazards and Hazardous Materials
Sargent Quarry 3.9-12 ESA / D201901577.01
Draft EIR July 2022
Solid waste from packaging and ranch-related items (e.g., barbed wire) found on site would also be disposed of during construction. Most of the waste would be non-hazardous and would be disposed of or recycled in accordance with state and local requirements, as described further in Section 3.14, Utilities and Service Systems. Any hazardous materials that are produced as a result of Project construction, such as during maintenance of heavy equipment, would be collected and transported away from the site, as required by the California Hazardous Waste Control Law.

Sanitary waste would be managed using portable toilets and hauled for off-site disposal until construction of the septic system is completed.

With these protections in place, the public and the environment would be protected from exposure to hazardous materials during their routine transport, use, and disposal. The impact during construction would be less than significant.

Operation
Mining Pits, Conveyor Belts, and Processing Plant
Mining would require limited use of hazardous materials, including standard fuels, oils, and lubricants for excavation, grading, and hauling equipment. The conveyor belts would be electric, so they would not use any fuel, but could require some hazardous materials for maintenance (e.g., solvents or lubricants). The Project would require occasional deliveries of fuel and cleaning supplies and the use and storage of various hazardous materials, including acetylene gas, antifreeze (ethylene glycol), diesel fuel, flocculants (powder and liquid), gear oil, high-pressure grease, hydraulic fluid, motor oils, oxygen gas, turbine oil, and absorbents (for spill containment and cleanup). In addition, herbicides could be used for weed control and/or to maintain FMZs. Hazardous wastes used during operation would be removed from the site in accordance with hazardous waste handling and disposal requirements, including sanitary waste from the proposed septic system and portable toilets, used absorbents, and waste oil and filters. Fuels, oils, and any other hazardous materials that would be used would be stored on site in designated areas. The Project site would be fenced and gated, so the public would not be able to access areas where hazardous materials stored or used. In addition, a three-strand barbed wire fence would be placed along the perimeter of the mining area and inspected monthly to ensure any breaks would be repaired immediately.

Fuels and oils for mobile equipment would be used and stored within the processing plant area in aboveground storage tanks (ASTs) with fuel delivered on an as-needed basis. Fueling of vehicles and equipment would occur at the aboveground fuel dispensing facility located near the quarry offices. Other materials, including new oil and waste oil, antifreeze, and hydraulic fluids would also be stored in ASTs and smaller containers at designated storage sites within the processing plant area. All tanks would be compliant with State regulations and contain secondary containment or be double-walled ASTs to ensure any spills or leaks are contained. All materials delivered to the Project site would be in approved USDOT packaging and all commercial vehicles transporting hazardous materials to the Project site would be required to have the proper USDOT hazardous materials placards.

All storage and handling of hazardous materials would comply with federal, state, and local requirements to minimize inadvertent contamination of groundwater and accidental spillage into

3. Environmental Setting, Impacts, and Mitigation Measures

3.9 Hazards and Hazardous Materials
Sargent Quarry 3.9-13 ESA / D201901577.01
Draft EIR July 2022
open water bodies. Accidents or mechanical failure involving heavy equipment or leaks and spills from storage tanks could result in the accidental release of small quantities of fuel, lubricants, hydraulic fluid, or other hazardous substances. The Project includes a HMBP as required by law, and an Industrial SWPPP (Appendix I) to minimize the potential for spills and leaks from material handling and storage, along with minimizing exposure of significant materials to stormwater (as described in Section 3.10, Hydrology and Water Quality). Requirements include secondary containment or using double-walled ASTs, conducting regular inspections, and training employees to ensure proper handling, storage, transport, and disposal techniques and methods are implemented.

Moving parts, such as motors associated with conveyor belt equipment, would be serviced on a regular basis, and unscheduled maintenance would be conducted as necessary. Adherence to the HMBP as would further ensure that all handling, storage, and disposal of hazardous materials would be conducted in accordance with proven practices to minimize exposure to workers or the public.

In addition, a SWPPP was completed to cover proposed operations on the site (see Appendix I).

The SWPPP will include provisions to prevent the potential discharge of pollutants caused by equipment operation, material storage, and fueling as well as a description of containment controls and site-specific erosion and sediment control criteria. The SWPPP would include protective measures that would be implemented in the Project site, such as good housekeeping practices to maintain a clean and orderly facility, preventative maintenance such as regular inspection and maintenance of equipment, spill cleanup procedures, proper material handling and waste management including keeping hazardous material and waste containers closed when not in use, any major rebuilding of heavy equipment is completed off site, and ensure that all employees are provided adequate training to implement compliance activities. The SWPPP requires maintenance of records to document compliance. See Section 3.10, Hydrology and Water Quality, for further discussion of the SWPPP and protection of surface water resources. Because the Applicant and its contractors would be required to comply with the SWPPP and BMPs, the potential for an accidental release that could result in substantial harm to the public or environment would be minimized, and if such an accident did occur, would ensure that public health and the environment are protected from harm. This impact would be less than significant.

Access Roads, Rail Spur, and Road Improvements
The physical components of the access roads, road improvements, and rail spur would only result in the use of hazardous materials during necessary maintenance, including resurfacing, throughout the life of the Project. The roads would be used to transport hazardous materials to the Project site for the uses described above, and to transport hazardous wastes away from the Project site for proper disposal. Oil and chemical vendors, equipment operators, and waste haulers would be required to comply with the on-site speed limit and instructed to exercise caution when driving near ASTs and associated equipment as required by law. Drivers would be instructed to respond to an emergency by shutting off the pump or closing the emergency shutoff valve at the delivery truck product compartment. A spill containment kit would be located on employee vehicles and trains arriving at the site. If a spill occurs, employees would use absorbent material from these kits to prevent chemicals or oils from leaving the area. For larger spills, the on-site earthmoving equipment would be used to create a berm to contain the spill so that it can be cleaned up consistent with regulatory requirements.

3. Environmental Setting, Impacts, and Mitigation Measures

3.9 Hazards and Hazardous Materials
Sargent Quarry 3.9-14 ESA / D201901577.01
Draft EIR July 2022
Herbicides could be used for weed control and to maintain FMZs. All herbicide application and disposal would be conducted in accordance with applicable State and federal regulations that minimize health and safety risks.

With adherence to applicable regulatory requirements, impacts would be less than significant.

Reclamation
Quarry equipment, structures associated with the processing plant, and storage yard debris would be removed when the mining operation ceases. All remaining fuel, oil, and lubricants removed from equipment and any remaining fuel in the storage tanks would be transferred to an appropriate container and disposed of in accordance with the manufacturers’ specifications and consistent with applicable regulatory requirements.

Revegetation would require weed control to reduce the occurrence of non-native plants that may invade the revegetated areas; methods would include mowing, removal by hand, herbicide use and/or with managed grazing. Any herbicide use would comply with applicable laws and regulations, which would minimize the risk of accident or exposure
When reclamation activities conclude, fuel tanks and other hazardous materials containers would be transported by licensed haulers to an approved disposal or recycling facility in accordance with laws and regulations. For example, prior to closure of any AST used to hold hazardous material, the Applicant would be required to obtain a tank closure permit from the County Department of Environmental Health and follow its tank closure guidelines (County of Santa Clara 2021a).

Guidelines outline appropriate tank cleaning methods and methods to make tanks previously containing flammable materials safe for removal. Tank removal must be witnessed by a representative of the County Hazardous Materials Compliance Division, who may determine that soil sampling is required. In addition, a closure application for aboveground hazardous materials storage facilities may be required. Adherence to state and local regulations would reduce the potential for releases due to transportation and disposal of hazardous materials and would require soil investigation and remediation if indications of hazardous materials releases were observed.

Since routine inspections and ongoing maintenance of on-site equipment would be implemented to ensure equipment integrity is maintained, and because the Applicant and its contractors would be required to comply with all hazardous materials laws and regulations for the transport, storage, use, and disposal of hazardous materials, the potential to create a substantial hazard to the public or the environment would be less than significant.

Summary
Adherence to applicable laws and regulations, and implementation of the SWPPP, would ensure that all handling, storage, and disposal of hazardous materials would during all components of Project construction and operation would be conducted in accordance with proven practices to minimize exposure to workers or the public.

Mitigation: None required.

3. Environmental Setting, Impacts, and Mitigation Measures

3.9 Hazards and Hazardous Materials
Sargent Quarry 3.9-15 ESA / D201901577.01
Draft EIR July 2022
Significance after Mitigation: Less than significant.
_________________________
Impact 3.9-2: The Project could create a hazard to the public or the environment through accidental release of existing soil contaminants, such as historic pesticide residues, into the environment. (Less than Significant with Mitigation) This impact discussion corresponds to Significance Criterion (b) and focuses on the potential for accidental releases of existing sources of contamination on the Project site.

Construction
The Phase I Environmental Site Assessment found no indication that there are contaminated soils on portions of the Project site that would be disturbed during construction; therefore, the risk of accidental release of hazardous materials from construction of all Project components would be less than significant.

Operation
Mining
The Phase I Environmental Site Assessment indicated the possibility of localized pesticides in onsite soils from historic use at the on-site corral area located at the northeast portion of the Project site. The area would be used as the permanent overburden stockpile area and would not require excavation. However, because pesticides may have been used in the on-site corral area and soil could be disturbed during placement of overburden, the Phase I Environmental Site Assessment recommended shallow soil sampling be completed in the corral area. Disturbance of pesticides could create a significant hazard due to accidental release of these contaminants, if present in the soils. This would be a significant impact.

All Other Components
The Phase I Environmental Site Assessment found no indication that there are contaminated soils elsewhere on the Project site; therefore, the risk of accidental release of hazardous materials from all other components of the Project would be less than significant.

Reclamation
Following implementation of Mitigation Measure 3.9-2 during the operation phase, on-site contaminated soils, if present, would be remediated. Therefore, there would be no further risk of release of historic pesticides into the environment during reclamation, and no impact would occur.

Summary
The only portion of the Project site identified where the potential for exposure to pesticides used historically is the corral area in the northeast potion of the Project site. This area would be disturbed during placement of the overburden stockpile, which could result in release of contaminants, if present. This would be a significant impact.

3. Environmental Setting, Impacts, and Mitigation Measures

3.9 Hazards and Hazardous Materials
Sargent Quarry 3.9-16 ESA / D201901577.01
Draft EIR July 2022
Mitigation Measure 3.9-2: The Project Applicant shall analyze and remove suspected residual pesticides in corral on-site soils. This measure applies to construction and mining and applies only to the corral area soils identified in the Phase I Environmental Site Assessment. Specifically, the Applicant shall implement the following:
a) Prior to issuance of a grading permit or any soil-disturbing activities, including placement of overburden material, within the corral area (shown on Figure 3 in Appendix H), the Project Applicant shall have soil samples collected and analyzed by a qualified environmental professional to determine if residual pesticides are present in on-site soils within the corral area. If residual pesticides are detected at levels that exceed regulatory thresholds, the geographical and vertical extent of contamination shall be identified, and recommendations for a Health and Safety Plan and methods for cleanup shall be implemented, as applicable. This work shall be performed under the oversight of the County’s Site Cleanup Program (SCP) within the Department of Environmental Health (DEH) Site Mitigation Programs (County of Santa Clara 2021b) with copies of all documentation provided to the County Department of Planning and Development.
b) If residual pesticides are present at the corral site, then the Applicant shall have soils containing pesticides removed from the site and characterized and disposed of according to the California Hazardous Waste Regulations. Contaminated soil that exceeds regulatory thresholds shall be handled by trained personnel using appropriate personal protective equipment (PPE) and engineering and dust controls, in accordance with local, state, and federal laws, such as those enforced by Cal/OSHA and the Bay Area Air Quality Management District (BAAQMD). Any contaminated soils that are removed from the site shall be disposed of at a licensed hazardous materials disposal site.

Significance after Mitigation: Less than significant
By requiring that soils be tested and that any pesticide-contaminated soils be removed and disposed of in an appropriate facility, Mitigation Measure 3.9-2 would ensure that workers, the public and the environment are protected from exposure to those residual pesticides during all ground-disturbing phases of the Project. Thus, with implementation of Mitigation Measure 3.9-2, environmental impacts from pesticides would be reduced to less than significant with mitigation.
_________________________

3.9.4.4 Cumulative Analysis
Impact 3.9-3: The Project would contribute to the cumulative increases in the risk of exposure to hazardous materials (Less than Significant with Mitigation) The geographic scope of impacts associated with hazardous materials generally encompasses the Project site, a 0.25-mile radius area around the Project site and the roadways that could be used to transport hazardous materials for the Project use. A 0.25-mile radius area allows for a conservative cumulative analysis that ensures that all potential cumulative impacts will be assessed. Hazards and exposure risks related to hazards and hazardous materials are typically localized in nature since they tend to be related to isolated events and on-site existing hazardous conditions and/or hazards

3. Environmental Setting, Impacts, and Mitigation Measures

3.9 Hazards and Hazardous Materials
Sargent Quarry 3.9-17 ESA / D201901577.01
Draft EIR July 2022
caused by the Project’s construction or operation. A geographic scope of a 0.25-mile radius area also coincides with the distance used to determine whether hazardous emissions or materials would have a significant impact upon an existing or proposed school, as discussed above.

As described in Section 3.1.6, Cumulative Scenario, there are several projects, primarily infrastructure and capital improvement projects, as well as private site developments, proposed within a 15-mile radius of the Project site. Only one project, the U.S. 101 Widening, is within

0.25 miles of the Project site. Construction and maintenance of this highway improvement would involve the use of hazardous materials. That project is dependent on state funding, and at this time the project is only 1 percent funded with no known schedule. However, the widening could occur within the 30-year life of the Project. If an accidental release of hazardous materials occurred at both the highway construction and the Project, it could result in greater exposure to hazardous materials then a single accidental release. Compliance with applicable laws and regulations governing the transport, storage and use of hazardous materials would assure that accidental releases would be prevented or contained and cleaned up promptly. Therefore, it is unlikely that there would be an accidental release from both the Project and the highway widening that could combine in a manner that would result in a substantial risk to construction employees, Project employees and/or nearby residents. For this reason, the Project’s contribution to cumulative risk of exposure to hazardous materials would not combine with the incremental contributions of other projects in the cumulative scenario to cause a significant cumulative effect. Accordingly, the cumulative impact related to the transport, use, and storage of hazardous materials would be less than cumulatively considerable, and thus less than significant.

With respect to the accidental release of existing environmental contaminants, as explained in Section 3.9.3, Environmental Setting, there is no indication of an existing significant cumulative effect relating to hazards and hazardous materials in the study area (such as widespread contamination by historic use of pesticides). The impact related to Project disturbance and accidental release of historic pesticide residues would be local to the Project site and would have minimal potential to combine with releases from other sites, such as by accidental release to the same waterway. Nonetheless, if such releases were to occur, the cumulative impact on human health and/or the environment could be significant, and the Project’s contribution to this cumulative impact would be considerable. Therefore, this impact is considered significant.

Mitigation Measure 3.9-3: Implement Mitigation Measure 3.9-2.

Significance after Mitigation: Less than significant
Implementation of Mitigation Measure 3.9-2 would ensure that accidental releases from the Project site would be avoided by removing any identified contaminated soils in accordance with all applicable regulations for handling of hazardous wastes. This would reduce the Project’s contribution to any potential cumulative impact to a level that is not cumulatively considerable, and thus less than significant. _________________________

3. Environmental Setting, Impacts, and Mitigation Measures

3.9 Hazards and Hazardous Materials
Sargent Quarry 3.9-18 ESA / D201901577.01
Draft EIR July 2022

3.9.5 References
California Department of Toxic Substances Control (DTSC). 2021. EnviroStor database.

Available online at: http://www.envirostor.dtsc.ca.gov/?surl=g77jn. Accessed July 26, 2021.

California Governor’s Office of Emergency Services (Cal OES). 2014. Hazardous Material Business Plan FAQ. http://www.caloes.ca.gov/. Accessed on December 14, 2020.

Cal OES. 2017. State of California Emergency Response Plan. http://www.caloes.ca.gov/ PlanningPreparednessSite/Documents/California_State_Emergency_Plan_2017.pdf.

October 1, 2017.

California Department of Conservation, Geologic Energy Management Division (CalGEM). 2021. Well Finder. Available online at: https://maps.conservation.ca.gov/doggr/ wellfinder/#openModal/-121.56891/36.92616/13. Accessed March 18, 2021.

Cornerstone Earth Group. 2016. Phase I Environmental Site Assessment. November 2016.

County of Santa Clara. 2008. Santa Clara County Operational Area Emergency Operations Plan.

County of Santa Clara. 2021a. Hazardous Materials Compliance Division. Closures. Available online at: https://hazmat.sccgov.org/programs-and-services/closures. Accessed July 26, 2021.

County of Santa Clara. 2021b. Hazardous Materials Compliance Division. Site Mitigation Program. Available online at: https://hazmat.sccgov.org/programs-and-services/sitemitigation-programs. Accessed July 26, 2021.

State Water Resources Control Board (SWRCB). 2021. GeoTracker Database. Available online at:
https://geotracker.waterboards.ca.gov/map/?CMD=runreport&myaddress=sargent%2C+ca.

Accessed March 12, 2021.

Triad Holmes Associates. 2016. Industrial Storm Water Pollution Prevention Plan (SWPPP), Sargent Quarry. September 2016.

U.S. Environmental Protection Agency (USEPA). 2021. Emergency Planning and Community Right-to-Know Act. Available online at: https://www.epa.gov/epcra/what-epcra. Accessed March 18, 2021.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-1 ESA / D201901577.01
Draft EIR July 2022

3.10 Hydrology and Water Quality

3.10.1 Introduction
This section describes the baseline conditions relevant to surface water and groundwater hydrology and water quality for the Sargent Quarry Project (Project) as well as the applicable federal, State, and local laws, ordinances, and regulations relevant to water resources. The physical setting and baseline conditions provide the basis for the analysis of surface water and groundwater hydrology and water quality impacts, which includes consideration of whether the Project would violate water quality standards or waste discharge requirements, alter existing drainage patterns of the site or area, contribute to or create polluted runoff, degrade surface and groundwater quality, or increase flood risks on- and off-site. Detailed reports considered in the analysis include a drainage study, groundwater analysis, industrial Stormwater Pollution Prevention Plan (SWPPP), and water supply assessment (WSA). Each is provided in Appendix I. The availability of water to supply the Project is addressed in Section 3.14, Utilities and Service Systems.

Public comments received on the NOP (Appendix A) relevant to water resources included concerns that Project implementation could degrade surface and groundwater quality as a result of sediment and other pollutants transported off-site in runoff, result in reduced stream flows in surface waters downgradient of the Project site (such as the Pajaro River), contribute contaminants (such as sediment or other pollutants) from settling pond discharges to surface waters, and impact existing wells and/or result in reduced surface flows in the Pajaro River and contributing tributaries as a result of groundwater-surface water interactions from proposed groundwater extractions. These comments are addressed below.

3.10.2 Regulatory Setting

3.10.2.1 Federal
Clean Water Act
Under the Clean Water Act of 1977, the U.S. Environmental Protection Agency (USEPA) seeks to restore and maintain the chemical, physical, and biological integrity of the nation’s waters. The statute employs a variety of regulatory and non-regulatory tools to reduce direct pollutant discharges into waterways and manage polluted runoff. The Clean Water Act authorizes the USEPA to implement water quality regulations. The relevant sections of the Act are summarized below.

Clean Water Act Section 303: Water Quality Standards and Implementation Plans Section 303 of the Clean Water Act requires states to designate beneficial uses for water bodies or segments of water bodies and to establish water quality standards to protect those uses for all waters of the U.S. Under Section 303(d), states, territories, and authorized tribes are required to develop lists of impaired waters. Impaired waters are waters that do not meet water quality standards established by the state, even after point sources of pollution have been equipped with the minimum required levels of pollution control technology. The law requires that these jurisdictions establish a priority ranking for listed waters and develop action plans to improve

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-2 ESA / D201901577.01
Draft EIR July 2022
water quality. Inclusion of a water body on the Section 303(d) List of Impaired Water Bodies triggers development of a Total Maximum Daily Load (TMDL) for that water body and a plan to control the associated pollutant/stressor on the list. The TMDL is the maximum amount of a pollutant/stressor that a waterbody can assimilate and still meet the water quality standards. Typically, a TMDL is the sum of the allowable loads of a single pollutant from all contributing point and nonpoint sources. In accordance with Section 303(d), the Central Coast Regional Water Quality Control Board (CCRWQCB) has identified impaired water bodies within its jurisdiction, and the pollutant or stressor responsible for impairing the water quality. Detailed discussion of impaired water bodies relevant to the Project, including the pollutants that cause the impairments, and the potential sources of the pollutants are discussed in Section 3.10.3.2, Surface Water Resources.

Clean Water Act Section 401: Water Quality Certification Section 401 of the Clean Water Act (33 U.S.C. Section 1341) requires any applicant for a federal license or permit to conduct any activity that may result in a discharge of a pollutant into navigable waters to obtain a certification from the State in which the discharge originates. The certification ensures that the discharge will comply with the applicable effluent limitations and water quality standards (see Section 3.4, Biological Resources, for additional details). The nine Regional Water Quality Control Boards, including the CCRWQCB, are responsible for implementing Section 401 in California.

Clean Water Act Section 402: National Pollutant Discharge Elimination System The NPDES permit program under Section 402 is one of the primary mechanisms for controlling water pollution through the regulation of sources that discharge pollutants into waters of the United States. The USEPA has delegated authority of issuing NPDES permits in California to the California State Water Resources Control Board (SWRCB), which delegates authority among the nine regional boards. The CCRWQCB regulates water quality in the vicinity of the Project site.

The NPDES permit program is discussed in detail in Section 3.10.2.2.

Section 404: Permits for Fill Placement in Waters of The United States Waters of the United States (including wetlands) are protected under Section 404 of the Clean Water Act. Any activity that involves a discharge of dredged or fill material into waters of the United States, including wetlands, is subject to regulation by the U.S. Army Corps of Engineers (USACE) (see Section 3.4, Biological Resources, for additional details).

California Toxics Rule, 40 CFR 131.38
In 2000, the USEPA promulgated numeric water quality criteria for priority toxic pollutants and other provisions for water quality standards to be applied to waters within California, filling a previously existing gap in California water quality standards. These federal criteria are legally applicable in California for inland surface waters, enclosed bays, and estuaries for all purposes and programs under the Clean Water Act. The USEPA and the SWRCB have the authority to enforce these standards, which are incorporated into the NPDES permits that regulate existing discharges in the vicinity of the Project site.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-3 ESA / D201901577.01
Draft EIR July 2022
Federal Emergency Management Agency
The 100-Year floodplain denotes an area that has a 1 percent chance of being inundated during any 12-month period. Pursuant to the National Flood Insurance Act of 1968, floodplain zones (Special Flood Hazard Areas [SFHA]) are determined by the Federal Emergency Management Agency (FEMA) and used to create Flood Insurance Rate Maps (FIRMs). These tools assist communities in mitigating flood hazards through land use planning. FEMA also outlines specific regulations, intended to be adopted by the local jurisdictions, for any construction, whether residential, commercial, or industrial within 100-year floodplains.

3.10.2.2 State
Porter-Cologne Water Quality Control Act
The Porter-Cologne Water Quality Control Act (Porter-Cologne Act, Division 7 of the California Water Code) provides the basis for water quality regulation within California. This Act establishes the authority of the SWRCB and the nine RWQCBs. The SWRCB administers water rights, sets State policy for water pollution control, and implements various water quality functions throughout the State, while the RWQCBs conduct planning, permitting, and most enforcement activities.

The Porter-Cologne Act requires the SWRCB and/or the RWQCBs to adopt statewide and/or regional water quality control plans, the purpose of which is to establish water quality objectives for specific water bodies. The CCRWQCB has prepared the Water Quality Control Plan for the Central Coastal Basins (Basin Plan) (CCRWQCB 2019) that establishes water quality objectives and implementation programs to meet the stated objectives and to protect the beneficial uses of the water bodies (discussed in detail in Section 3.10.3.2, Surface Water Resources). The PorterCologne Act also authorizes the NPDES program under the Clean Water Act, which establishes effluent limitations and water quality requirements for discharges to waters of the state. Most of the implementation of SWRCB’s responsibilities is delegated to the nine RWQCBs. Under the NPDES program, the CCRWQCB has established permit requirements for stormwater runoff applicable to the Project site (see below).

NPDES Waste Discharge Program
The Clean Water Act established the NPDES program to protect the water quality of receiving waters of the United States. In California, the SWRCB and RWQCBs implement the NPDES program, which is integrated with the Porter-Colognes Act’s waste discharge requirements (WDRs) program. Under Clean Water Act Section 402, discharging pollutants to receiving waters of the United States is prohibited unless the discharge is in compliance with an NPDES permit.

Effluent limitations serve as the primary mechanism in NPDES permits for controlling discharges of pollutants to receiving waters both from construction activities and discharges from operation of municipal or industrial facilities. When developing effluent limitations for an NPDES permit, a permit applicant must consider limits based on both the technology available to control the pollutants (i.e., technology-based effluent limits) and limits that are protective of the water quality standards of the receiving water (i.e., water quality-based effluent limits1 if technology‐based 1 Water quality-based effluent limits specify the level of pollutant (or pollutant parameter), generally expressed as a concentration, that is allowable.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-4 ESA / D201901577.01
Draft EIR July 2022
limits are not sufficient to protect the water body). For inland surface waters and enclosed bays and estuaries, the water‐quality‐based effluent limitations are based on criteria in the National Toxics Rule and the California Toxics Rule, and objectives and beneficial uses defined in the applicable Basin Plan. There are two types of NPDES permits: individual permits tailored to an individual facility and general permits that cover multiple facilities or activities within a specific category.

The NPDES permits relevant to the Project are described below.

NPDES Construction General Permit
The State of California adopted a Construction General Permit as part of the NPDES program on September 2, 2009 (Order No. 2009-0009-DWQ as amended by 2010-0014-DWQ and 2012- 0006-DWQ). The Construction General Permit regulates construction site stormwater management. Dischargers whose projects disturb 1 or more acres of soil, or whose projects disturb less than 1 acre but are part of a larger common plan of development that in total disturbs 1 or more acres, are required to obtain coverage under the Construction General Permit for discharges of stormwater associated with construction activity.

The Project would be required to comply with the permit requirements to control stormwater discharges from the sites where proposed Project elements are being constructed (such as the stormwater treatment facility, access roads, and creek crossings). Construction activity subject to this permit includes clearing, grading, and disturbances to the ground, such as stockpiling or excavation as would occur on the future soil borrow site, as well as construction of buildings.

In the vicinity of the Project site, the Construction General Permit is implemented and enforced by the CCRWQCB, which administers the stormwater permitting program. To obtain coverage under this permit, Project operators must electronically file Permit Registration Documents, which include a Notice of Intent (NOI), a SWPPP, and other compliance-related documents. An appropriate permit fee must also be submitted to SWRCB. SWPPPs are a required component of the Construction General Permit and must be prepared by a State-Qualified SWPPP Developer (QSD) and implemented by a State-Qualified SWPPP Practitioner (QSP). SWPPPs must describe the specific erosion control and stormwater quality BMPs being implemented to minimize pollutants in stormwater runoff, and detail their placement and proper installation.

The SWPPP identifies BMPs that must be implemented to reduce construction effects on receiving water quality based on potential pollutants. The BMPs identified are directed at implementing both sediment and erosion control measures and other measures to control potential chemical contaminants. In addition, the SWPPP is required to contain a visual monitoring program and a sediment monitoring plan if the site discharges directly to a water body listed on the 303(d) list for sediment. Examples of typical construction BMPs include scheduling or limiting certain activities to dry periods, installing sediment barriers such as silt fence and fiber rolls, and maintaining equipment and vehicles used for construction. Non-stormwater management measures include installing specific discharge controls during certain activities, such as paving operations, vehicle and equipment washing and fueling. The SWPPP also includes descriptions of the BMPs to reduce pollutants in stormwater discharges after all construction phases have been completed at the site (post-construction BMPs). Dischargers are responsible for notifying the

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-5 ESA / D201901577.01
Draft EIR July 2022
CCRWQCB of violations or incidents of non-compliance, as well as for submitting annual reports identifying deficiencies of the BMPs and how the deficiencies were corrected.

The Construction General Permit includes several new requirements (as compared to the previous Construction General Permit, 99-08-DWQ), including risk-level assessment2 for construction sites, an active stormwater effluent monitoring and reporting program during construction (for Risk Level II and III sites), rain event action plans for certain higher risk sites, 3 and numeric
effluent limitations for pH and turbidity as well as requirements for qualified professionals that prepare and implement the plan. The risk assessment and SWPPP must be prepared by a QSD and implementation of the SWPPP must be overseen by a QSP. Site risk level is determined using a combination of the sediment risk of the project and the receiving water quality risk. Projects can be characterized as Risk Level 1, Level 2, or Level 3, and the minimum best management practices (stormwater controls) and monitoring that must be implemented during construction are based on the risk level. Under the direction of the QSD, the QSP conducts routine inspections of all BMPs, conducts surface water sampling, when necessary, and reports site conditions to the State and/or Regional Water Quality Control Board as part of Construction General Permit compliance monitoring and reporting using the Stormwater Multi-Application Reporting and Tracking System (SMARTS).

Project construction activities would be consistent with the Construction General Permit; compliance is required by law and the provisions of the permit and BMPs for construction and post-construction phases have proven effective in protecting water quality at construction sites and downgradient receiving waters (SWRCB 2013).

NPDES Industrial General Permit
In November 1990, as part of administering its Clean Water Act responsibilities, the USEPA published final regulations that establish application requirements for storm water permits. The regulations require specific categories of industrial facilities which discharge storm water to obtain coverage under the NPDES General Permit No. CAS000001 for Discharges of Storm Water Associated with Industrial Activities (NPDES Industrial Permit). The NPDES Industrial Permit requires regulated facilities to (among other things):
• Prepare and maintain a SWPPP (discussed below);
• Implement storm water BMPs to minimize discharge of pollutants in runoff; • Conduct regular inspections of the facility, during both wet and dry weather; • Collect and analyze samples of runoff at least twice per year from each discharge location; and
• Prepare and submit annual reports on storm water management activities. 2 The Construction General Permit defines three levels of risk (Risk Level I, II, and III) that may be assessed for a construction site. Risk is calculated based on the “project sediment risk”, which determines the relative amount of sediment that can be discharged given the project and location details, and the “receiving water risk” (the risk sediment discharges pose to the receiving waters).
3 Those sites that have a high potential for mobilizing sediment in stormwater and drain to a sediment-sensitive waterbody.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-6 ESA / D201901577.01
Draft EIR July 2022
Included in these “industrial facilities” categories are quarrying and mining facilities. Industrial facilities that discharge stormwater either directly to surface waters or indirectly, must be covered by a permit. This includes the discharge of “sheet flow” through a drainage system or other conveyance. The permit also prohibits non-storm water discharges into the industrial stormwater system and is intended to authorize discharges composed entirely of industrial stormwater.

The Industrial General Permit Order 2014-0057-DWQrequires dischargers to file a NOI requesting coverage under this permit. The Industrial General Permit also requires dischargers to prepare and implement both a SWPPP and a Monitoring and Reporting Program (MRP) and to submit these plans to the RWQCB. The Applicant has prepared a SWPPP and a SWPPP Monitoring Program (Appendix I.4) to comply with these requirements. The SWPPP is intended to achieve two purposes: (1) to identify and evaluate sources of pollutions associated with industrial activities that could affect the quality of stormwater discharged and authorized nonstormwater discharged from a facility; and (2) to identify and implement site-specific BMPs that the facility is committed to implementing to minimize or prevent discharge of pollutants associated with industrial activities that may be in stormwater. The SWPPP addresses elimination of non-storm water discharges, pollutant sources and associated BMPs, storm water management, sedimentation and erosion control practices, preventative maintenance and good housekeeping practices, spill prevention and response, inspections, record keeping, and employee training.

Anti-Degradation Policy
The SWRCB Anti-Degradation Policy, formally known as the Statement of Policy with Respect to Maintaining High Quality Water in California (SWRCB Resolution No. 68-16), restricts degradation of surface and groundwaters. Specifically, this policy protects water bodies where existing quality is higher than necessary for the protection of beneficial uses and requires that existing high quality water bodies be maintained to the maximum extent possible.

Under the Anti-Degradation Policy, any actions that can adversely affect water quality in all surface and groundwaters must: (1) be consistent with maximum benefit to the people of California; (2) not unreasonably affect present and anticipated beneficial use of the water; and (3) not result in water quality less than that prescribed in water quality plans and policies. Furthermore, any actions that can adversely affect surface waters are also subject to the federal Anti-Degradation Policy (40 CFR Section 131.12) developed under the Clean Water Act. Discharges from the Project that could affect surface water quality would be required to comply with the Anti-Degradation Policy, which is included as part of the NPDES permit requirements for point source discharges.

Sustainable Groundwater Management Act of 2014
The Sustainable Groundwater Management Act of 2014 (SGMA) applies to all groundwater basins in the state (Water Code Section 10720.3). By enacting the SGMA, the legislature intended to provide local agencies with the authority and the technical and financial assistance necessary to sustainably manage groundwater within their jurisdiction (Water Code Section 10720.1).

Pursuant to SGMA, any local agency that has water supply, water management, or land use responsibilities within a groundwater basin may elect to be a “groundwater sustainability agency”

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-7 ESA / D201901577.01
Draft EIR July 2022
(GSA) for that basin (Water Code Section 10723). Groundwater sustainability agencies will have additional powers under the SGMA to manage groundwater within the basin, including, for example, the power to conduct investigations of the basin, to require registration of groundwater extraction facilities and metering of groundwater extractions, regulate groundwater extractions from individual groundwater wells or wells generally, and to assess fees on groundwater extractions (see generally, Water Code Section 10725 et seq.). GSAs must prepare a Groundwater Sustainability Plans (GSP) that describe measures and objectives the GSA would implement to sustain groundwater resources for the current and future beneficial uses in a particular basin. The objectives can include those to:
• Provide long-term, reliable, and efficient groundwater supply for agricultural, domestic, and municipal and industrial uses,
• Provide reliable storage for water supply resilience during droughts and shortages, • Protect groundwater quality,
• Prevent subsidence
• Support beneficial uses of interconnected surface waters, and • Support integrated and cooperative water resource management.

SGMA also provides local agencies with additional tools and resources designed to ensure that the state’s groundwater basins are sustainably managed. The new groundwater well proposed for the Project site would be constructed within the Llagas Subbasin. Valley Water is the GSA for the Llagas Subbasin, and adopted the Groundwater Management Plan (GWMP) for the Santa Clara and Llagas subbasins in November 2021 (Valley Water 2021a).4 Groundwater management actions developed in the GWMP would pertain to the groundwater pumping proposed by the Project. As the Project site is close to the basin boundary of the Llagas and San Benito subbasins, proposed groundwater management actions in the GSA prepared for the San Benito subbasin (SBCWD 2021) may also apply to groundwater use by the Project. Additionally, although located west of the Project site, the Pajaro Valley Groundwater Management Agency (PV Water) is supplied by the Pajaro River. PV Water submitted the Basin Management Plan as an alternative to a GSP in December 2016 and in July 2019, DWR approved the alternative plan as functionally equivalent to a GSP. Groundwater management actions identified by PV Water's GSP may also apply to groundwater use at the Project site.

Executive Order N-7-22
In response to the continuing drought, Executive Order (EO) N-7-22 was signed in March 2022.

The provisions of EO N-7-22 include a requirement that, prior to approving a permit for a new groundwater well and/or alterations to an existing well in a basin subject to the SGMA and classified as medium- or high-priority, the permitting jurisdiction must obtain written verification from the applicable Groundwater Sustainability Agency that groundwater extraction by the proposed well would not be inconsistent with the applicable, adopted Groundwater Sustainability 4 Valley Water’s Groundwater Management Plan contain information that is functionally equivalent to elements required SGMA for a GSP.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-8 ESA / D201901577.01
Draft EIR July 2022
Plan. In addition, the permitting jurisdiction must determine that the proposed well would not likely interfere with the production and functioning of existing nearby wells, and would not likely cause subsidence that would adversely affect or damage nearby infrastructure.

Surface Mining and Reclamation Act
The Surface Mining and Reclamation Act of 1975 (SMARA), as amended, and its implementing regulations establish requirements for mineral extraction that are designed to prevent or minimize the negative public health, property, and environmental impacts associated with surface mining.

As related to hydrologic and water quality issues, the process of reclamation includes maintaining water quality, and minimizing flooding and erosion damage to wildlife and aquatic habitats caused by surface mining. The requirements of the Act apply to any surface mining operations that disturb more than one acre or remove more than 1,000 cubic yards of material. Therefore, the proposed Project is subject to the requirements of SMARA.

Under SMARA, all operators of surface mines in California must prepare and submit for approval by the lead agency a reclamation plan, along with financial assurances that sufficient funds will be available to accomplish reclamation (Pub. Res. Code Section 2770). This plan must be prepared by the Applicant prior to initiation of mineral extraction activities. SMARA is administered by lead agencies (most often counties or cities) and the California Department of Conservation. The County is the SMARA Lead Agency for this Project.

SMARA and its implementing regulations contain number of provisions addressing geotechnical and slope stability issues (see Section 3.7, Geology, Soils, and Paleontological Resources, for further detail) as well as drainage diversion structures, waterways (14 California Code of Regulations (CCR) Section 3706) and stream protection including surface and groundwater (14 CCR Section 3710). SMARA also dictates that erosion control methods shall be designed for the 20-year storm, and shall control erosion and sedimentation. The SMARA regulations also require reclamation plans to include performance standards for drainage and erosion to protect water quality, including streams, surface and groundwater. These performance standards must ensure compliance with the CWA, Porter-Cologne and other legal requirements (14 CCR Sections 3706, 3710).

3.10.2.3 Local
County of Santa Clara General Plan
The County of Santa Clara General Plan Safety and Noise element contains the following planning strategies, policies, and implementation recommendations regarding water quality:

Water Quality & Watershed Management
Strategy #1: Reduce Non-Point Source Pollution
Policy C-RC 19: The strategies for maintaining and improving water quality on a countywide basis, in addition to ongoing point source regulation, should include:
a. effective non-point source pollution control

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-9 ESA / D201901577.01
Draft EIR July 2022
b. restoration of wetlands, riparian areas, and other habitats which serve to improve Bay water quality
c. comprehensive Watershed Management Plans and BMPs
Policy C-RC 20: Adequate safeguards for water resources and habitats should be developed and enforced to avoid or minimize water pollution of various kinds, including:
a. erosion and sedimentation
b. organic matter and wastes
c. pesticides and herbicides
d. effluent from inadequately functioning septic systems e. effluent from municipal wastewater treatment plants
f. chemicals used in industrial and commercial activities and processes g. industrial wastewater discharges
h. hazardous wastes
i. non-point source pollution
Policy R-RC 13: Sedimentation and erosion shall be minimized through controls over development, including grading, quarrying, vegetation removal, road and bridge construction, and other uses which pose such a threat to water quality.

Policy R-RC 35: Flood control modifications to be made in streams that have substantial existing natural areas should employ flood control designs which enhance riparian resources and avoid to the maximum extent possible significant alteration of the stream, its hydrology, and its environs.

Policy R-RC 43: Large scale grading and clearing of land should not be allowed if it will significantly degrade valuable habitat or impair surface water quality.

Policy R-RC 73: The extraction of mineral resources, including sand and gravel, should be carefully conditioned and regulated to mitigate potential adverse environmental impacts, including mitigation measures for potential increases in siltation and/or pollution of water resources in order to adequately protect the local water supply.

County of Santa Clara Surface Mining and Land Reclamation Standards The Santa Clara County Zoning Ordinance contains standards for surface mining operations that include protections for streams and water-bearing aquifers. Section 4.10.370, Part II, Subsection A.9 requires mining operations “…to be conducted in a manner so as to keep adjacent streams, percolation ponds, or water bearing strata reasonably free from undesirable obstruction, silting, contamination, or pollution of any kind. The objective is to prevent discharges, which would result in higher concentrations of silt than existed in off-site water prior to mining operations.” It further requires the removal of vegetation and overburden prior to surface mining to be kept to the minimum practicable and requires stockpiles to be managed to limit water and wind erosion.

This subsection states that permit applicants shall comply with applicable requirements of federal,

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-10 ESA / D201901577.01
Draft EIR July 2022
state, and local permitting agencies regarding all matters which are within the jurisdiction of those agencies, including but not limited to:
• Excavation in the natural or artificially enlarged channel of any river, creek, stream or natural or artificial drainage channel when such excavation may result in the deposit of silt therein • Maximum depth of excavation shall not be below existing streambed or groundwater table except in such cases where the reclamation plan indicates that a lake or lakes will be part of the final use of the land or where such plan indicates that adequate fill to be used to refill such excavation to conform to the approved reclamation plan
• Erosion control facilities, such as detention basins, settling ponds, desilting or energy dissipater ditches, stream bank stabilization, and diking necessary to control erosion Lastly, the subsection requires that “Excavations,” which may penetrate near or into usable waterbearing strata, will not reduce the transmissivity or area through which water may flow unless approved equivalent transmissivity or area has been provided elsewhere, nor subject such groundwater basin or sub-basin to pollution or contamination.” Santa Clara Valley Water District
The Santa Clara Velley Water District (Valley Water) operates as the water supply and flood management agency for the County. Its stewardship also includes creek restoration, pollution prevention efforts, and groundwater recharge. Valley Water requires permits for all well construction and abandonment/ destruction work, and most exploratory boring for groundwater exploration.

Santa Clara County faces periods of severe drought, and Valley Water recognizes that water conservation is critical to sustainability. The 2020 Urban Water Management Plan (UWMP) prepared by Valley Water (Valley Water 2021b) projects water demand through 2045 for normal and dry years, describes the water supplies, and outlines a five-stage water shortage contingency plan to decrease water demand during periods of water shortage, including water conservation measures that may be enacted by Valley Water. The 2020 UWMP includes water supply estimates for future single dry years and multiple dry year periods on a Countywide basis.

Valley Water along with 15 cities, the County of Santa Clara, and business, agriculture, and streamside property owners and other environmental interest groups formed the Water Resources Protection Collaborative in 2002 to clarify and streamline local permitting for streamside activities.

In 2007, the Collaborative adopted a guidebook entitled Guidelines and Standards for Land Use Near Streams: A Manual of Tools, Standards, and Procedures to Protect Streams and Streamside Resource in Santa Clara County (2006), and replaced its existing streamside protection ordinance (Ordinance 83-2) with the Water Resources Protection Ordinance. The guidebook provides a framework for evaluating permit applications and establishing permit conditions.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-11 ESA / D201901577.01
Draft EIR July 2022

3.10.3 Environmental Setting

3.10.3.1 Regional Setting
The Project site is located within the greater Pajaro River watershed. The Pajaro River watershed is approximately 1,300 square miles in size and covers portions of Santa Clara, Santa Cruz, San Benito, and Monterey counties. Water resources in this region include rivers, streams, sloughs, marshes, wetlands, channels, and underground aquifers. The Pajaro River marks the southern boundary of Santa Clara County, as it abuts San Benito County, and drains to Monterey Bay near Watsonville. Major tributaries to the Pajaro River include Uvas-Carnadero Creek, Llagas Creek, and Pacheco Creek (Valley Water 2020a).

The Project site is located within the Lower Uvas Creek subwatershed and the Lower Pajaro River subwatershed (Figure 3.10-1). The northern portion of the Project site in the vicinity of Tar Creek, which includes the proposed processing plant and permanent overburden stockpile area, is located within the Lower Uvas Creek subwatershed area, which drains an area of 40 square miles, and is a part of the Uvas-Llagas watershed (104 square miles) within the larger Pajaro River Watershed. Tar Creek drains the northern portion of the Project site within the Lower Uvas Creek subwatershed and joins Uvas-Carnadero Creek upstream of its confluence with the Pajaro River at the drainage point of the subwatershed. The Uvas-Llagas watershed originates from both the Santa Cruz Mountains and the Diablo Range and land use is a largely rural supporting farming communities and cattle ranches with significant open space and natural areas. The remaining portions of the Project site, including the proposed mining areas, access roads, and conveyor belts, are located within the Lower Pajaro River subwatershed, covering an area of 52 square miles. In the vicinity of the Project site, the Lower Pajaro River subwatershed is drained primarily by Sargent Creek which flows into the Pajaro River south of the Project site approximately 1.3 miles upstream of the confluence of Pescadero Creek and the Pajaro River (Valley Water 2020b).

The uplands of the southern Santa Cruz Mountains and the Sargent Hills are surrounded by Gilroy-Hollister Valley area Llagas, Bolsa, and San Juan Bautista groundwater subbasins to the east and the Pajaro Valley Groundwater Basin, managed by the Pajaro Valley Water Management Agency (PVWMA) to the west. The upland areas are not considered part of the groundwater subbasins. However, the water district, Valley Water, identifies the Sargent Hills, including the Project site, as a recharge area for the Llagas Area Groundwater Subbasin (Llagas Subbasin).

While most of the Project site is not located within a designated groundwater basin, the northern part of the Project site, in the vicinity of Tar Creek, overlies the Llagas Subbasin and the area underlying proposed mining Phases 3 and 4 is near the edge of the San Juan Bautista Groundwater Subbasin (San Juan Bautista subbasin). Businesses, residents, and farmers in south Santa Clara County are primarily reliant on groundwater for their water supply, and Valley Water actively recharges the Llagas Groundwater Subbasin by percolating local and imported water through a series of streams, channels, and percolation ponds.
49 Creeks
SWRP Area
Project Site
Subwatersheds
Lower Llagas Creek
Lower Pajaro River
Lower Uvas Creek
Upper Pajaro River
Upper Uvas Creek
N
Figure 3.10-1
Creeks and Subwatersheds within the SWRP Area
SOURCE: Valley Water, 2020a SCC Sargent Quarry
SFO/19xxxx/D191577.00 - SCC Sargent Quarry/05 Graphics-GIS-Modeling/Illustrator

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-13 ESA / D201901577.01
Draft EIR July 2022

3.10.3.2 Surface Water Resources
Climate and Topography
Climate has a significant influence on water use on a seasonal and annual basis. This influence increases for water uses in outside areas, such as dust control, pond evaporation, and landscape irrigation. The county has a Mediterranean climate, characterized by dry summers and wet winters with year-round moderate-to-warm temperatures. Reflecting this pattern, water demand in the county is greater in the summer than in the winter (Appendix I.3). The annual average temperature in the Project site and vicinity is 58°F with an extreme high of 105°F and extreme low of 16°F. Average precipitation in the region is approximately 21 inches annually, the majority of which falls between October and March (Appendix B, Mining and Reclamation Plan). At the Project site, average precipitation between 2009 and 2020 was 12 inches annually (Appendix I.3).

The 100-year, 24-hour precipitation event generates 6.96 inches of rainfall (Appendix I.1).

Site topography consists of gently rolling to moderately steep hillsides with moderate to welldefined drainages. Elevations of the Project site range from a high of approximately 650 feet National Geodetic Vertical Datum (NGVD) near the northwestern edge of the site boundary, to a low of approximately 120 feet NGVD at the easterly edge of the processing area (Appendix B).

Project Site Hydrology
The Project site is located in the hills west of the Pajaro River where it leaves the Gilroy-Hollister Valley and flows south and west through a canyon to coastal plains and the Pacific Ocean near Watsonville (Appendix I.3). The Pajaro River flows close to the eastern and southern boundaries of the Project site and is at the lowest elevation of all the surface waterways in the area. It is the regional drain for surface and groundwater discharge. The Project site is surrounded by agricultural and ranching lands to the north, south, and west. U.S. 101 bounds the site on the east.

Two major creeks, Tar Creek and Sargent Creek, drain the Project site (Figure 3.10-2). In addition to Tar Creek and Sargent Creek, other smaller drainages and ephemeral channels with a defined bed and bank bisect the Project site. The Project site vegetation cover includes a light to moderate growth of grasses, shrubs, and some riparian habitat in the drainage areas (see Section 3.4, Biological Resources, for more information). The following discussion describes the key surface water features and site drainage for the Project site moving from north to south.

The Tar Creek watershed is larger and more incised than the Sargent Creek watershed to the south (Appendix B). Tar Creek has a watershed area of approximately 6.5 square miles (Appendix I.1), flowing west to east just north of the proposed processing plant site, and enters a concrete box culvert under the railroad track and U.S. 101. Tar Creek then continues to flow to the east through riparian vegetation for about 1,700 feet before entering Carnadero Creek approximately 0.3 mile upstream of the Carnadero Creek-Pajaro River confluence.

For the portion of the property that falls within the mining boundary of Phases 1 and 2, stormwater from the higher elevations and ridges flows into two ephemeral drainages and several drainage channels which traverse across the site from the high point at the northwestern edge of the mining area and join Tar Creek just north of the processing area. Two smaller drainage areas !.
3KDVH
Pit
3KDVH
Pit
Spring
3KDVHV
3LW
Processing
Plant
ee
k
(
"N
0 2,000
Scale in Feet
Legend
!. Project Supply Well
3URMHFW)DFLOLWLHV
Sargent Creek watershed
Stream Channel
Ephemeral Stream
Riparian Vegetation
SOURCE: Appendix I
SFO/19xxxx/D191577.00 - SCC Sargent Quarry/05 Graphics-GIS-Modeling/Illustrator SCC Sargent Quarry
Figure 3.10-2
Locations of Sargent Creek Watershed Features

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-15 ESA / D201901577.01
Draft EIR July 2022
with ephemeral channels drain easterly through the proposed overburden stockpile area and the Phase 1 and 2 mining sites towards the Pajaro River. The stormwater runoff in these small drainage channels readily infiltrates into the soils. However, when infiltration capacity has been reached, accumulated surface stormwater runoff drains southeast down through natural swales and ravines into culverts, passing under U.S. 101 and flowing into the Pajaro River (Appendix B).

Sargent Creek is the primary surface water feature relevant to the proposed mining areas and drains the majority of the Project site. Sargent Creek has a watershed area of 1.7 square miles and drains to the south, emptying into the Pajaro River approximately 2 miles downstream of the proposed processing plant site (Appendix B). The Sargent Creek headwaters are located west and south of proposed mining Phases 1 and 2 and Sargent Creek runs primarily from north to south adjacent to the proposed quarry access road and conveyor belt and bisects the southern portion of the mining site where Phases 3 and 4 of mining operation are proposed. An impoundment of Sargent Creek exists about 2,000 feet upstream of the proposed Phases 3 and 4 quarry access road crossing of the creek. The impoundment was created when cattle ranchers using the property built a 6-foot-high earthen dam at least 50 years ago. The depth of water behind the dam is about 5 feet at the deepest. Normal season flow generally is entirely retained by the impoundment, resulting in no flow within Sargent Creek downstream of the impoundment for much of the year other than when flows south of the impoundment contribute directly to the creek via sheet flow or from smaller ephemeral drainage channels (Appendix I.1). The drainage of the existing topography of the areas proposed for mining as part of Phases 3 and 4 currently flow to Sargent Creek. The primary water feature associated with Phases 3 and 4 is an ephemeral drainage channel that drains approximately 75 acres upgradient of the Phase 3 mining area to the northeast and flows through the proposed Phase 3 mining area and into Sargent Creek approximately 100 feet downstream of the proposed access road creek crossing.

Surface Water Quality
The quality of surface water is primarily a function of land uses in the watershed. Local land uses influence the quality of surface waters through point source discharges (i.e., discrete discharges from discharge pipes) and nonpoint source discharges (e.g., direct storm runoff from slopes).

Surface water runoff is generated by precipitation that cannot be absorbed into the ground in the period following a storm. Pollutants and sediments are transported in watersheds by stormwater runoff that reaches streams, rivers, and storm drains. The amount of surface water runoff is a factor of precipitation, ground saturation, and available permeable or pervious ground surfaces.

Permeability is a measure of how quickly water can penetrate a surface area.

The Basin Plan (see Section 3.10.2.2) designates beneficial uses for specific surface waters and establishes water quality objectives to ensure those designated beneficial uses do not become impaired. Additionally, the Basin Plan contains implementation plans and policies for all waters within the jurisdictional area it covers. In the Project site and vicinity, the Basin Plan does not specifically identify beneficial uses for Sargent Creek or Tar Creek. However, Carnadero Creek downstream of Tar Creek and the Pajaro River downstream of Sargent Creek have beneficial uses identified (CCRWQCB 2019). The designated beneficial uses for Carnadero Creek include warm freshwater habitat (WARM); cold freshwater habitat (COLD); municipal and domestic supply

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-16 ESA / D201901577.01
Draft EIR July 2022
(MUN); and both water-contact and non-contact recreation (REC1 and REC2). The designated beneficial uses of the Pajaro River include agricultural supply (AGR); both water-contact and non-contact recreation (REC1 and REC2); municipal and domestic supply (MUN); warm freshwater habitat (WARM); cold freshwater habitat (COLD); and spawning, reproduction, and/ or early development (SPWN).

Section 303(d) of the Clean Water Act requires states, territories and authorized tribes to develop lists of impaired waters, i.e., waters that do not meet water quality standards or successfully support designated beneficial uses, even after point sources of pollution have been outfitted with the minimum required levels of pollution control technology. Currently Carnadero Creek and the Pajaro River are listed as having impaired beneficial uses (USEPA 2016). These water bodies are impaired by a variety of contaminants including sediment/turbidity, dissolved oxygen, pH, nitrate, chlorpyrifos, DDT, diazinon, chlorodane, unknown toxicities, boron, E. Coli, and fecal coliform. Such constituents originate from a variety of sources, but generally include agricultural activities, resource extraction, urban runoff/storm sewers, and unknown sources. In the context of the Project, the most relevant water quality impairments in Carnadero Creek and the Pajaro River are those for sediment/turbidity (USEPA 2021).

Turbidity refers to water that is cloudy, muddy, or opaque (turbid) because of suspended soil particles, algae, microbes, or organic matter. These tiny particles can absorb heat and raise water temperatures, reduce oxygen for aquatic animals, reduce native aquatic plant growth, clog fish gills, and smother fish eggs and aquatic insects. Within the watershed, turbidity levels increase as a result of removing streamside vegetation or channelizing streams, filling wetlands or other waters, increasing impervious areas, and routing rainwater runoff directly into a lake, stream, or sewer system rather than to areas where it can soak in to underlying soils. Sediment becomes a water quality issue when stormwater runoff erodes soil into waterways from fields, construction sites, yards, logging areas, streets and parking lots, and other areas. Sediment can make water murky, hurt the health and habitats of fish and other aquatic animals, interfere with uses like fishing and swimming, and carry other pollutants (USEPA 2021).

As discussed in Section 3.10.2, Regulatory Setting, the Clean Water Act requires jurisdictions to establish priority rankings for 303(d) listed waters and develop action plans, known as TMDLs, to improve water quality. A sediment TMDL was established for waterways within the Pajaro River Watershed due to the finding that anthropogenic watershed disturbances have accelerated the natural processes of erosion and sedimentation in the Pajaro River and tributary water bodies.

Excessive sedimentation has caused the water quality objective for sediment to be exceeded, and the existing sediment load and rate have interfered with the beneficial uses of these waterbodies including fish and wildlife (COLD, MIGR, and SPWN) (CCRWQCB 2021).

Flood Risk
The Project site is located within Flood Zone D: areas in which flood hazards are undetermined, but possible. The FEMA flood risk determination is based, in part, on the fact that the FIRM for the Project site did not include an assessment by FEMA for flood risks associated with Tar Creek (FEMA 2009). To determine flood risk for the Project site, the 100-year flood limits of Tar Creek were modeled (Appendix I.1). Based on the assessment of the 100-year flood limits of Tar Creek,

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-17 ESA / D201901577.01
Draft EIR July 2022
the proposed processing plant is located within an area at risk of inundation during a 100-year flood event (Figure 3B in Appendix I.1). The 100-year flood limits of Tar Creek extend south into the proposed processing plant site for approximately 350 feet with surface elevations ranging from 164.7 to 158.9 feet mean sea level (msl), representing approximately 2- to 3-foot inundation depths for portions of the processing plant site.

Portions of the Project site are adjacent to but not within a dam failure inundation zone for Anderson Dam, which is located approximately 18 miles to the northeast (SCVWD 2016). The inundation zone generally follows the Pajaro River.

3.10.3.3 Groundwater Resources
Information and data on groundwater occurrence and flow beneath the Project site was derived from a subsurface investigation report prepared by Sierra Geotechnical Services Inc. (SGS) (SGS 2016); a technical peer review of the SGS investigation by Golder Associates (Golder) (Golder 2017a); a SGS report responding to Golder’s comments (SGS 2017b); and an evaluation of groundwater conditions and potential mining impacts prepared by Todd Groundwater (Appendix I.2). The section below considers the findings from these studies and presents what is known of the groundwater conditions underlying the Project site.

The available information indicates that groundwater occurs beneath the Project site within a shallow groundwater table5 and may be contained in isolated fractures and granular sediments (landslide deposits) above the groundwater table (referred to as perched water6). No groundwater wells have been constructed in the mining areas or elsewhere on the site and thus, the presence and depth of a continuous groundwater table cannot be confirmed.

Beneath the Phases 1 and 2 pit, the presence of groundwater is identified at the surface by springs and riparian vegetation and by groundwater seepage reported by SGS in seven exploratory borings drilled to depths ranging between 35 and 95 feet below the ground surface. The spring is north of the Phases 1 and 2 pit at an elevation of 530 feet. A strip of riparian vegetation is present along the uppermost reach of Sargent Creek; vegetation of that type usually indicates the presence of a shallow water table (Figure 3.10-2) (Appendix I.2). A similar corridor of riparian vegetation is present along a lower reach of Sargent Creek, from the Phases 3 and 4 mining areas down to the Pajaro River floodplain. SGS encountered groundwater seepage in its exploratory borings at depths above the proposed final mining depths in the Phases 1 and 2 pit. SGS did not encounter groundwater in exploratory borings drilled at locations near the proposed Phases 3 and 4 pits.

Under current site conditions, rainfall infiltrates into the ground surface of the Project site and recharges the shallow water table, which flows through the sediments and rock downslope until it intersects the creek channel and discharges as surface flow. Shallow groundwater flow typically 5 The groundwater table is typically the first water encountered beneath the unsaturated upper soil horizon. The water table is usually recharged by rainfall infiltrating through overlying soils the water surface is not confined (remains at atmospheric pressure). Water elevations of the groundwater table fluctuate in response to recharge rates and outflow. 6 Perched groundwater is subsurface water that occurs in soils and rock that are above the groundwater table. These perched zones are often localized and not extensive compared to the water table or a deeper aquifer. Perched groundwater is separated from an underlying body of groundwater by an unsaturated zone.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-18 ESA / D201901577.01
Draft EIR July 2022
mimics the direction of the ground slope. Thus, a shallow water table is likely along the lower reaches of Sargent Creek. In the mining areas, the water table is highest beneath ridges and groundwater flows approximately in the direction of the ground slope. Therefore, it is likely that the surface watershed divide coincides with the groundwater divide and groundwater near the Phase 3 and 4 pits flows toward the lower riparian corridor along Sargent Creek and groundwater near the Phase 1 and 2 pit flows toward the Pajaro River (Appendix I.2). However, the groundwater flow system in the upper part of the Sargent Creek watershed (near the Phases 1 and 2 pit) could be more complex, because faults that pass through the area could act as barriers to groundwater flow.

The Project site does not overlie an identified groundwater basin, but the Sargent Hills are bordered by the Llagas, Bolsa, and San Juan Bautista groundwater subbasins to the east. Valley Water identifies the Sargent Hills, including the Project site, as a recharge area for the Llagas Area Groundwater Subbasin (Llagas Subbasin). The northwestern portion of the Project site, in the vicinity of Tar Creek, partially overlies the Llagas Subbasin, and the area of the proposed processing plant site is situated at the basin’s edge. The proposed Phase 3 and 4 pits are along the western boundary of the San Juan Bautista Groundwater Subbasin (San Juan Bautista subbasin).

Businesses, residents and farmers in south Santa Clara County rely primarily on groundwater for their water supply. Valley Water actively recharges the Llagas Groundwater Subbasin by percolating local and imported water through a series of streams, channels, and percolation ponds.

The Project would obtain a portion of its water supply from a groundwater production well proposed to be located near the processing plant site. The proposed well would be constructed in the deep water-bearing sediments within of the Llagas Subbasin. There are several other wells to the north and east of the proposed Project well. The closest belongs to the Applicant. The second closest is a monitoring well owned and operated by Valley Water. The third closest is one of ten wells owned by a neighboring landowner (Sun & Sons LP) that appear to be irrigation wells; this well would be located 690 feet from the processing plant and 2500 feet from the Phase 1 and 2 mining areas. The well is located next to a perennial7 reach of the Pajaro River where the river gains flow by groundwater discharge from the Bolsa and Llagas subbasins. Construction information is not available for the irrigation well closest to the Project’s proposed supply well. However, driller’s logs for other wells in the area indicate that a typical depth to the top of the well screen is 100 feet and a typical total well depth is 400 feet. Groundwater level data (2012–2015) from a monitoring well belonging to Valley Water indicate that water levels recovered in winter each year to 9 feet below ground surface, which probably corresponds to the elevation of the nearby Pajaro River. In summer, water levels declined to 25 feet below ground surface in 2012 (normal year) and 45 feet below ground surface in 2014 and 2015 (dry years). Thus, the lowest static (non‐pumping) water level in a dry year was 55 feet above the top of the screen (Appendix I.2).

Groundwater Quality
Water quality testing indicates that groundwater in the Santa Clara and Llagas subbasins is generally of good quality that meets drinking water standards in most wells for all constituents tested. The exception is nitrate, which was found above the regulatory standard of 10 parts per million (ppm) in 30 percent of the South County water supply wells sampled (primarily domestic 7 Pertains to a creek or river that flows throughout the year.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-19 ESA / D201901577.01
Draft EIR July 2022
wells) due to current and historic sources (Valley Water 2017). The median concentration for nitrate ranges from 1.5 milligrams per liter (mg/L) in the Santa Clara Plain shallow aquifer to 10 mg/L in the Llagas Subbasin shallow aquifer. The median total dissolved solids (TDS) concentration ranges from 370 mg/L in the Llagas Subbasin principal aquifer to 438 mg/L in the Santa Clara Plain shallow aquifer. Valley Water continues to implement Salt and Nutrient Management Plans to support reduced nitrate loading and exposure (Valley Water 2017).

In 2017, Valley Water analyzed data from 24 monitoring wells near recycled water irrigation sites in the Santa Clara and the Llagas Subbasins. N-Nitrosodimethylamine (NDMA) and several perfluorinated compounds (PFCs) were detected in recycled water used for irrigation. Unlike some previous sampling events, NDMA was not detected in any wells. PFCs were detected in some shallow wells in the Santa Clara and the Llagas subbasins. Most monitoring wells demonstrated stable or decreasing trends for key water quality indicators, suggesting that groundwater is not significantly affected by recycled water use (Valley Water 2017).

There is no information on the quality of groundwater underlying the Project site. However, perched water or groundwater in a shallow water table is not typically used as domestic drinking water supply because of unreliable yields, fluctuating groundwater levels due to seasonal surface recharge, and generally poor water quality (e.g., increased TDS, elevated pH and possibly high nitrate levels), which may not meet state drinking water standards.

3.10.4 Impact Evaluation

3.10.4.1 Approach to the Analysis
Compliance with applicable federal, state, and local laws and regulations is assumed in the analysis of impacts because these regulatory requirements are mandatory and the application of the associated protective measures (such as BMPs, Monitoring and Reporting Plans, and the application of corrective actions) is non-discretionary minimizes and/or avoids hydrologic or water quality impacts. Further, regulatory agencies with jurisdiction and authority for oversight would require adherence to regulatory requirements as a condition of Project or permit approval and would continue to enforce applicable requirements throughout Project construction and operation phases.

To support the assessment of Project impacts, the Applicant provided the Sargent Quarry Mining and Reclamation Plan (Reclamation Plan) (Appendix B), a Preliminary Drainage Study prepared for the Project by Triad/Holmes Associates (Appendix I.1), and an Industrial SWPPP (Appendix I.4). These and other Applicant-provided studies were independently reviewed on the County’s behalf and were found, together with other information in the record, to be suitable for reliance as part of the CEQA process. In addition, several reports were prepared by or on behalf of the EIR preparers identified in Chapter 5, Report Preparation, including an Evaluation of Groundwater Conditions and Potential Mining Impacts memorandum and corresponding Addendum by Todd Groundwater (Appendix I.2), and an Additional EIR Support memorandum presenting an analysis of groundwater, groundwater/surface water quality, and groundwater/ surface water flow-related impacts (Appendix I.5). Where applicable, the results and findings of the supporting technical studies were incorporated into the assessment of impacts.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-20 ESA / D201901577.01
Draft EIR July 2022

3.10.4.2 Significance Criteria
Consistent with CEQA Guidelines Appendix G, a project would have a significant impact on hydrology or water quality if it would:
a) violate any water quality standards or waste discharge requirements, or otherwise substantially degrade surface or groundwater quality;
b) substantially decrease groundwater supplies or interfere substantially with groundwater recharge such that the project may impede sustainable groundwater management of the basin; c) substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, or through the addition of impervious surfaces, in a manner which would:
i. result in substantial erosion or siltation on- or off-site:
ii. substantially increase the rate or amount of surface runoff in a manner which would result in flooding on- or off-site;
iii. create or contribute runoff water which would exceed the capacity of existing or planned stormwater drainage systems or provide substantial additional sources of polluted runoff; or iv. impede or redirect flood flows;
d) in flood hazard, tsunami, or seiche zones, risk release of pollutants due to project inundation; or e) conflict with or obstruct implementation of a water quality control plan or sustainable groundwater management plan.

3.10.4.3 Project Impacts
Impact 3.10-1: Project construction grading and other activities would substantially degrade surface or groundwater quality. (Less than Significant with Mitigation) This impact discussion corresponds to Significance Criterion (a) and addresses whether Project construction would violate any water quality standards or waste discharge requirements, or otherwise substantially degrade surface or groundwater quality.

Construction
Access Road, Processing Plant, Conveyor Belt, Rail Spur, Roadway Improvements Construction of the proposed processing plant, conveyor belts, rail spur, access road, and roadway improvements would include earthwork activities (i.e., grading, excavation, and other soil-disturbing activities) and the placement of imported engineered soils. Stormwater runoff from disturbed soils associated with construction activities is a common source of pollutants (mainly sediment) to receiving waters. Earthwork activities can render soils and sediments more susceptible to erosion from stormwater runoff and result in the migration of soil and sediment in stormwater runoff to downgradient water bodies.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-21 ESA / D201901577.01
Draft EIR July 2022
The proposed processing plant site is immediately adjacent to and contributes runoff to Tar Creek. Additionally, a free-span bridge is proposed over Tar Creek to provide truck access to the processing plant from Old Monterey Road. The proposed access road and conveyor belt run north to south adjacent to Sargent Creek, and construction of the access road would include a creek crossing and installation of culverts near mining Phases 3 and 4. Improvements to the existing U.S. 101 on-ramp and portions of Old Monterey Road are proposed in areas upgradient of Project site drainage channels, tributaries, and/or other receiving waters. Excessive and improperly managed grading, excavation, soil stockpiling, or vegetation removal can lead to increased erosion of exposed earth and sedimentation of downgradient waters during rainy periods.

Removing streamside vegetation or channelizing streams, such as at the proposed Sargent Creek access road crossing, also could result in increased turbidity in downgradient surface waters.

In addition, construction would likely involve the use of various materials typically associated with construction activities such as paint, solvents, oil and grease, petroleum hydrocarbons, concrete and associated concrete wash-out areas. If improperly handled, these materials could result in pollutants being mobilized and transported off-site by stormwater runoff (nonpoint source pollution) and degrade receiving water quality.

Because the construction activities proposed as part of the Project would occur in an area that exceeds 1 acre in size, all construction activities must comply with NPDES regulations and obtain coverage under the State Construction General Permit. Under the Construction General Permit, the Applicant or its contractor(s) would be required to implement construction BMPs as set forth in a detailed construction SWPPP. The BMPs are designed to prevent pollutants from coming into contact with stormwater and to keep all products of erosion and stormwater pollutants associated with construction activities from moving off-site into receiving waters. Typical BMPs to be implemented at construction sites include placement of fiber rolls or gravel barriers to detain small amounts of sediment from disturbed areas, and temporary or permanent covering of stockpiles to prevent rainfall from contacting the stockpiled material. In addition to erosion control BMPs, SWPPPs also include BMPs for preventing the discharge of pollutants other than sediment (e.g., paint, solvents, concrete, petroleum products) to downstream waters. BMPs for pollutants include conducting routine inspections of equipment for leaks, maintaining containers of supplies such that the contents are clearly labeled, the integrity of the containers is not compromised, and ensuring that construction materials are disposed of in accordance with applicable regulations. Compliance with a Construction General Permit is required by law and has proven effective in protecting water quality at construction sites (SWRCB 2013).

Compliance with the requirements of the Construction General Permit, including the implementation of associated BMPs, would prevent the discharge of pollutants to surface waters or groundwater and minimize or eliminate potential degradation of surface water or groundwater quality during construction of the described Project components due to the transport of pollutants in stormwater from active construction sites. Additionally, because construction activities and proposed Project components such as the Tar Creek bridge and Sargent Creek access road crossing would affect jurisdictional surface water features, the Project would be required to obtain a Section 404 Clean Water Act permit from the USACE, Section 401 Water Quality Certification from the CCRWQCB, and Section 1600 Streambed Alteration Agreement from the CDFW prior to initiating any

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-22 ESA / D201901577.01
Draft EIR July 2022
construction activities within these areas (see Section 3.4, Biological Resources, for more information).

However, the Construction General Permit and associated SWPPP requirements do not specifically anticipate direct impacts to water quality that may result from work within stream channels, such as the proposed Tar Creek Bridge and Sargent Creek road crossing. Construction activities within stream channels pose an increased risk of water quality degradation due to the increased potential for erosion and sediment transport to occur within a disturbed channel bed. Also, as described in Section 3.4, Biological Resources, resource agency permits have not yet been issued and the conditions of those permits are not yet known. For these reasons, impacts to water quality from construction of the Tar Creek Bridge and Sargent Creek road crossing would be significant.

Mitigation Measure 3.10-1: Implement Mitigation Measure 3.4-4 from Section 3.4, Biological Resources.

Significance after Mitigation: Less than significant
Mitigation Measure 3.4-4 requires that specific targeted avoidance and minimization measures, performance standards, and control measures be implemented during the initial Project construction phases to reduce runoff of pollutants and to protect water quality during construction through avoiding and/or minimizing construction activities within stream channels. Further, all such measures would be monitored by the qualified biologist who will survey the Project site prior to issuance of any construction permits and be present to monitor construction activities during initial ground disturbance or vegetation clearing.

With implementation of Mitigation Measure 3.4-4, impacts relating to the violation of water quality standards, waste discharge requirements, or the degradation of surface and/ or groundwater quality due to construction of the Project would be less than significant. ________________________
Impact 3.10-2: Project operation and subsequent reclamation of the Project site would not substantially degrade surface or groundwater quality. (Less than Significant) This impact discussion corresponds to Significance Criterion (a) (see Section 3.10.4.2) and addresses whether Project operation and reclamation would violate any water quality standards or waste discharge requirements, or otherwise substantially degrade surface or groundwater quality.

Introduction
Project operation and reclamation of the Project site would involve grading, excavation, and earthmoving activities which could subject soil, either stockpiled or otherwise exposed, to erosion by stormwater runoff. Once dislodged by surface flow, soil particles become entrained in stormwater runoff and if not properly controlled, the sediment-laden runoff would be discharged to the various on-site ephemeral and/or intermittent drainage channels: Sargent Creek, Tar Creek, and ultimately to Carnadero Creek and the lower reach of the Pajaro River. Carnadero Creek and the Pajaro River are listed as impaired water bodies under Section 303(d) of the Clean Water Act due to sediment, among other pollutants.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-23 ESA / D201901577.01
Draft EIR July 2022
Additional sediment input to the downgradient receiving waters from the Project site could increase the sediment load, increase turbidity, and contribute to degradation of downstream water quality.

Operational and reclamation activities most likely to cause sediment to enter the waterways include initial development of the various project features (e.g., mining phase drainage and stormwater conveyance features and soil stockpiling), and ongoing quarrying activities, including topsoil and overburden removal, quarrying aggregate, transporting and storage of materials, and aggregate processing. In addition to sediment, other contaminants, such as grease, oil, or diesel fuel can enter the adjacent receiving waters if released during quarry operations. These compounds become attached to the sediment and are carried by stormwater runoff until the sediment settles out.

Regulatory Compliance
Project operation and reclamation would be required to adhere to the NPDES Permit for Industrial Activities (see Section 3.10.2.2), which includes specific water quality and hydrologic standards and requires monitoring of specified pollutants associated with the covered industrial activity and the subsequent correction of any water quality exceedances indicated by monitoring and reporting. The NPDES Permit for Industrial Activities requires that new dischargers who discharge into a water body with a 303(d) listed impairment are ineligible for coverage unless the discharger submits data and/or information, prepared by a Qualified Industrial Storm Water Practitioner (QISP), demonstrating that:
• The Discharger has eliminated all exposure to stormwater of the pollutant(s) for which the water body is impaired, has documented the procedures taken to prevent exposure on-site, and has retained such documentation with the SWPPP at the facility. • The pollutant for which the water body is impaired is not present at the Discharger’s facility, and the Discharger has retained documentation of this finding with the SWPPP at the facility. • The discharge of any listed pollutant will not cause or contribute to an exceedance of a water quality standard. This is demonstrated if: (1) the discharge complies with water quality standard at the point of discharge, or (2) if there are sufficient remaining waste load allocations in an approved TMDL and the discharge is controlled at least as stringently as similar discharges subject to that TMDL.

Because a TMDL for sediment has been approved for Carnadero Creek and the Pajaro River, and due to sediment exposure being an inherent part of proposed operation and reclamation activities, the receiving water body impairment listing will need to be reviewed by a QISP to be eligible for coverage.

Adherence to the NPDES Permit for Industrial Activities requires implementation of a SWPPP to establish physical and operational BMPs for pollution controls and the containment and control of runoff at non-erosive velocities. Consistent with NPDES requirements, a SWPPP has been prepared for the Project (Appendix I.4). Development of this SWPPP included identification of the primary proposed activity areas that would contribute to site runoff as well as activities that could result in the contribution of stormwater pollutants and the specific pollutants associated with those activities (Table 3.10-1).

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-24 ESA / D201901577.01
Draft EIR July 2022
TABLE 3.10-1

CONTRIBUTING ACTIVITY AREAS TO SITE RUNOFF
Area
No. Description Drainage Route(S) & Outfall
Activities That May
Contribute Pollutants Potential Pollutant(S)
Quarry-Related Contributing Activities
1 Plant Site
(7% impervious)
• Stormwater sheet flows west
to east across the plant to
on-site Sediment Basin
• Brow ditch collects the
stormwater and conveys it to
on-site Sediment Pond
• Culverts convey the
stormwater under the paved
access road to brow ditches
• On site Sediment Basin
collect the runoff from the
Plant Site
• Vehicle and equipment
parking
• Bone yard (storage of
misc. parts w/out fuel/oil)
• Diesel Fueling Area
• Stockpiling (processed
material and topsoil)
• Rock and Sand
processing
• Sediment
• Petroleum
hydrocarbons
• Oil and grease
• Solvents
• Diesel
• Antifreeze
• Human waste
2 Pits 1 and 2
(0% impervious)
• Swales around Pit 1 convey
stormwater to Sargent Creek
• Swale following benches
through Pit 1 conveys
stormwater to 3–36” culverts
under access road and outlet
to Sargent Creek
• Swales around Pit 2 convey
stormwater to Sargent Creek
northwest of Pit 2 and to
Pajaro River southeast of Pit
2 • Rock extraction
• Sand extraction
• Vehicle and equipment
parking
• Diesel Fueling Area
• Stockpiling
• Porta Potty
• Sediment
• Petroleum
hydrocarbons
• Oil and grease
• Solvents
• Diesel
• Antifreeze
• Human waste
• Disinfectants from
Chemical Toilets
3 Pits 3
(0 % impervious)
• Swale around west side of
Pit 3 conveys stormwater to
Sargent Creek
• Swale around south side of
Pit 3 conveys stormwater to
natural drainage feature and
outlets to Pajaro River
• Swale around north side of
Pit 3 conveys stormwater to
36” culvert that outlets to
natural drainage feature and
eventually reaches Pajaro
River
• Rock extraction
• Sand extraction
• Vehicle and equipment
parking
• Diesel Fueling Area
• Stockpiling
• Porta Potty
• Sediment
• Petroleum
hydrocarbons
• Oil and grease
• Solvents
• Diesel
• Antifreeze
• Human waste
• Disinfectants from
Chemical Toilets
4 Access Road to
Pits 1 and 2
• Runoff sheet flows across
the access road to Sargent
Creek
• Vehicle movement on
the access road
• Sediment
• Petroleum
hydrocarbons
• Oil and grease
• Diesel
The SWPPP specifies implementation of BMPs sufficient to reduce significant hydrologic and water quality impacts (see Table 3 on p. 21 of Appendix I.4), including the concentration of pollutants in Project site stormwater runoff identified in Table 3.10-1. Erosion control measures are specified in the SWPPP, including BMPs to address sediments generated during the operational phase of the quarry and mining area development. Because mining and reclamation operations require on-going grading activities, sedimentation basins are proposed throughout the Project site

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-25 ESA / D201901577.01
Draft EIR July 2022
during the operational and reclamation phases as the primary sediment control measures (Figure 2- 15). Additional BMPs specified in the SWPPP for controlling erosion and sedimentation (see Table 5 on p. 30 of Appendix I.4) include measures such as silt fences, berms, coir wattles, hay bales, or similar means to deter erosion, employed as necessary at locations of identified concern over the course of operations, depending upon the particular configuration of the grading work and roadways. If soil erosion continues, vegetation of soils would be implemented using a seed/spraying technique. Maintenance BMPs required as part of implementation of SWPPP include cleaning of accumulated sediment, debris, and potential contaminants from the on-site drainage facilities before the start of the rainy seasons and as needed during the rainy season. Also, as discussed in Section 2.4.3, active mining and aggregate processing would not operate if a rain event of one-half inch (i.e., 0.5-inch storm) or more is forecasted as such storm events hinder the ability to mine and process material and result in poor or dangerous operating conditions on Project site access roads.

Reducing or ceasing operations during large storm events and stabilizing exposed soils with temporary erosion control measures would minimize the potential for erosion and sediment transport in stormwater runoff from active industrial areas. Monitoring of weather conditions will occur consistent with the requirements of the Industrial SWPPP.

The standards and specific BMPs required as part of the SWPPP are industry-accepted methods that have been proven effective at attenuating concentrated stormwater flows, reducing erosion, and minimizing or avoiding the transport of pollutants associated with industrial activities in stormwater. These BMPs provide protection against water quality degradation, provided that they are maintained effectively and monitored regularly and that the SWPPP includes a monitoring and maintenance element with periodic scheduled monitoring of BMP performance and maintenance of BMP features. Consistent with NPDES requirements, the SWPPP includes a monitoring and reporting program that specifies inspections to be performed following implementation of the Project to ensure that BMPs are being successfully implemented and to identify conditions that may allow potential pollutants to be discharged with storm water and correct those conditions (see Table 6, p. 32 of Appendix I.4).

The performance of BMPs, including any related failures, improvements, and corrective actions taken as a result of periodic monitoring and reporting (see Section 13 of the Industrial SWPPP, Appendix I) would be described in annual regulatory reports submitted to the CCRWQCB.

Monitoring and prescribing corrective actions, if needed, under the MRP would minimize or avoid potential impacts on surface water and groundwater quality and would include additional targeted monitoring to ensure successful resolution of identified problem areas if a water quality protection standard (WQPS) exceedance is determined to have occurred under the MRP.

Contaminants and hazardous chemicals used in the proposed mining operations and during the reclamation phase would include vehicle fuel, oils, and lubricants, as well as solvents, acids, bases, batteries, antifreeze, heavy metals, and pesticides. The materials have the potential to spill during regular use, which could result in contaminated runoff from the site if spills are not properly contained and/or cleaned up. Vehicle refueling and service operations would occur at the designated maintenance shop within the processing plant area. Fueling and oil storage tanks would be set inside secondary containment structures to contain leaks and spills, and a Hazardous Material Business Plan and Spill Prevention Control Counter Measure Plan are included in the

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-26 ESA / D201901577.01
Draft EIR July 2022
Project (see Section 3.9, Hazards and Hazardous Materials), which would provide emergency and spill response procedures. In addition, as discussed above, implementation of the SWPPP requires inclusion of numerous BMPs related to the storage, processing and handling of aggregate materials and hazardous materials, maintenance of vehicles and equipment, and good housekeeping procedures for the processing plant area.

Water quality impacts are assessed in more detail below for specific Project elements, including consideration of the Project’s proposed storm drainage plan (see Project Description Section 2.4.3, Stormwater Drainage, for the operational phase, and Section 2.6.3, Erosion, and Sediment Controls, for the reclamation phase for details) and proposed erosion and sediment control features (Section 2.4.4).

Operation
Mining Pits
Active mining areas would be graded to achieve positive drainage consistent with the performance standards contained in SMARA’s implementing regulations for drainage and diversion (Appendix B), as described in detail in Section 2.4.4. Runoff from precipitation falling within the mining areas generally would drain into the quarry pit via a drainage system and be conveyed to stormwater retention and sedimentation basins within the mining pits (Figure 2-15 in Chapter 2, Project Description). Drainage improvements, including sediment basins and stormwater collection and conveyance systems, would be designed to accommodate the 24-hour, 100-year storm event.

Runoff from quarried slopes and benches would always be directed down to the quarry floor through drainage ditches that would be maintained during mining and relocated as mining moves into new areas. After final grading configuration of each bench has been achieved, runoff from the quarry slopes would be directed into interceptor ditches on the benches and proceed into drop inlets flowing into over side drain culverts. Each bench would be constructed with a minimum 4 percent back slope to prevent runoff from flowing over the quarried slopes and eroding exposed soils. Runoff from the quarry slopes would be directed into interceptor ditches on the benches or at the toe of the quarry slopes and then into either side collector ditches or a lined ditch that conveys stormwater to the basins. The collector, interceptor ditches, drop inlets, and over side drain culverts would be constructed after the final reclamation grading configuration of each bench has been achieved. The benches would minimize the chance of slope erosion or weakening of the slope resulting from runoff saturation (Appendix B).

The stormwater basins in the mining area pits would be constructed to capture sediment-laden water collected within the mining area and allow the sediment to settle out. The Applicant would expand the sediment pond with each new mining phase to accommodate the increased mining area, as necessary. Energy dissipaters would be located at the base of the slope where the runoff would flow into ditches that drain into the pit and basins. Runoff from the quarry slopes would join runoff from the quarry floor in the pit and basins. The basins would be sized such that stormwater generated on-site would be retained without discharge; the basins would retain stormwater until it percolates into the ground. Prior to each wet season, the quarry operator would

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-27 ESA / D201901577.01
Draft EIR July 2022
remove sediment from the pond to ensure sufficient retention capacity is available and to facilitate percolation, ensuring the pond would be prepared to receive runoff and sediment for the subsequent winter season. Surface runoff and drainage from surface mining areas, would be controlled by berms, silt fences, sediment ponds, revegetation, hay bales, or other erosion control measures, consistent with the SWPPP, to avoid and minimize erosion, gullying, sedimentation, and contamination of receiving waters from exposed soils and activities related to operation and reclamation consistent with the identified proposed activity areas and the specific pollutants associated with those activities (Table 3.10-1). Erosion control methods would be sized to accommodate runoff from not less than the 20-year/1-hour intensity storm event consistent with regulatory requirements (see Section 2.4.4).

Processing Plant
The processing plant is proposed to be located just south of Tar Creek. Stormwater runoff from the processing plant site would be contained on-site via a stormwater collection and conveyance system designed to address stormwater transport of the specific pollutants associated with proposed processing plant site activities (Table 3.10-1). Stormwater from the site would be collected and conveyed to the on-site stormwater sediment basin through graded brow ditches constructed adjacent to the access road, along the perimeter and within the interior areas of the site (Figure 2-15). Stormwater in this basin would be allowed to percolate on-site or be reused to supplement supply to the process water pond for processing plant operations (e.g., dust control, washing aggregate materials). The process water pond would be supplied via a new groundwater well (assessed under Impacts 3.10-3 and 3.10-5). The on-site sediment basin would also receive runoff from swales surrounding the adjacent overburden stockpiles. The sediment basin would be approximately 0.21 acre (surface area) and have a capacity of 0.45 acre-foot in order to accommodate the 24-hour, 100-year storm event.

Stockpiles at the processing plant would be stabilized, consistent with the SWPPP (Appendix I.1), to minimize and/or avoid erosion and transport of sediments in stormwater that may contribute to silt build-up in the sediment basin. Temporary erosion control BMPs to control erosion on the stockpiles during the rainy season include surrounding the stockpiles with devices such as coir wattles or silt fences and/or constructing drainage ditches that collect stormwater from the stockpiles and direct the flow into one of the proposed Project site sediment basins. Topsoil stockpiles that would not be used in the near-term would be hydro seeded to establish vegetative cover to minimize the potential for erosion of exposed soils. Additionally, an approximately 40- foot-tall visual screening berm would be constructed along the east side of the processing plant, adjacent to U.S. 101 (Figure 2-5a). The berm would be constructed using approximately 90,000 cubic yards (cy) of overburden from Phase 1. The berm would be graded to resemble the form and shape of the surrounding hill and would be planted with shrubs, grasses, and trees and irrigated so as to establish vegetative cover to stabilize exposed soils and minimize erosion and off-site sediment transport in stormwater.

To access the proposed processing plant, a bridge over Tar Creek would be constructed along with flood protection berms along both sides of the creek within the existing 100-year flood limits of the creek. Hydrologic and water quality impacts associated with the proposed Tar Creek Bridge and flood protection berms are assessed under Impact 3.10-8.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-28 ESA / D201901577.01
Draft EIR July 2022
Conveyor Belt, Rail Spur, Access Roads
For facilities like the Project, unpaved access roads, rail spurs, and other facilities such as the conveyor belt are considered to be part of the industrial activity and are subject to the requirements of the NPDES Industrial Permit. As a result, stormwater runoff and associated pollutants from the active site must be managed and controlled with BMPs. Following construction of the Project site access roads, conveyor belt, and rail spur, erosion and sedimentation, as well as the transport of other pollutants (such as oil and grease) would be controlled through implementation of the BMPs specified in the SWPPP (Appendix I.4) associated with the Industrial NPDES Permit. Such BMPs include the use of water trucks to spray unpaved and paved roads, restriction of activities during wet weather, routine inspection of the access roads for erosion and/or spills, the expansion of drainage facilities and sedimentation basins (as needed), and the use of jute matting, erosion control blankets, wattles, silt fences and sediment traps to mitigate areas where runoff is concentrated to reduce sediment levels in site runoff.

As part of the proposed stormwater drainage system (Section 2.4.3) and the proposed erosion and sediment controls (Section 2.4.4), eight sediment and drainage control basins would be located intermittently along the conveyor belt/access road alignment (Figure 2-9 and Figure 2-10). These basins would have surface areas ranging from 0.01 to 0.34 acres and capacities of 0.01 to 1.45 acre-feet. The sediment basins would receive all surface water from the conveyor belt/access road alignment and capture sediment and other pollutants transported in stormwater to ensure water quality is not degraded in downstream receiving waters. Prior to each wet season, the Applicant would remove accumulated sediment from the sediment basins. The sediment basins would capture pollutants in runoff from active industrial areas and avoid direct discharges of stormwater to on-site or downgradient receiving waters such as Sargent Creek or the Pajaro River.

For the reasons discussed above, the operational impacts of the Project would be less than significant.

Reclamation
As described in Section 2.6, reclamation activities would involve equipment and building removal, regrading, re-soiling, installation of drainage and erosion control, and revegetation of exposed soils. The Tar Creek bridge and the access road that runs parallel to the conveyor belt would be left in place, but the Sargent Creek crossing would be removed, and the Sargent Creek channel would be restored to its natural pre-project condition. Residual fuels and oils would be removed from the site during reclamation activities. As described for construction (Impact

3.10-1) and operational activities (above), reclamation activities could subject soil, either stockpiled or otherwise exposed, to erosion by stormwater runoff and result in the transport of sediment or other pollutants on-site (such as oil or grease) to downstream receiving waters.

The Industrial SWPPP developed for the Project (Appendix I.4), including implementation of BMPs, monitoring and reporting, and corrective actions, would apply to operation phase and reclamation phase activities until reclamation is complete. In addition to the minimization and avoidance measures specified for implementation under the SWPPP, the Reclamation Plan (Appendix B) includes reclamation standards and BMPs that would be implemented in addition

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-29 ESA / D201901577.01
Draft EIR July 2022
to those specified in the SWPPP and that are specifically designed to address erosion, sediment transport, and the contribution of pollutants to stormwater or downgradient receiving waters.

The Reclamation Plan includes specific standards and BMPs related to re-soiling, back filling, grading, slope stabilization, removal of structures and equipment, control of contaminants, erosion and sedimentation, and the protection of on-site and downstream beneficial uses of water (see Section 4.5 of Appendix B). Erosion and sediment control measures to be implemented during the reclamation phases of the project would include revegetation of disturbed slopes, benches, and valley floor areas. The implementation of BMPs, such as jute matting, erosion control blankets, wattles, silt fences and sediment traps, would ensure areas where runoff is concentrated are managed such that erosion and the transport of sediment or other pollutants in the runoff is avoided or minimized. Implementation of BMPs would ensure downgradient receiving water quality is not degraded prior to completion of restoration.

Reclamation activities would be monitored to ensure that reclamation of the site is done in compliance with the approved Mining and Reclamation Plan. The monitoring program incorporates site-specific criteria to measure compliance for specific reclamation activities including grading/topography, sediment and erosion control, revegetation, irrigation, and ongoing maintenance and monitoring. BMPs included in the monitoring and maintenance plan for reclamation activities include:
• Use of a water truck to wet down work areas while filling and compacting is underway or while the ground surface is being ripped or disked and while topsoil is being spread onto the reclaimed slopes, benches, and valley floor;
• The lining of drainage ditches comprised of loose soils with rock to reduce erosion; • Inspection and repair of rill erosion either by regrading the area or by adding erosion control measures to reduce the concentration of water causing the erosion; • Inspection of drainage facilities annually prior to wet season; and • Inspection of revegetated slopes prior to September 1st each year for five consecutive years following the conclusion of mining operations to ensure that the plant materials have successfully become established and are properly functioning to hold the soil on graded slopes, reducing the potential for erosion (consistent with SMARA and County Use Permit requirements).

These measures would ensure that reclamation activities have a less-than-significant impact on water quality.

Summary
Surface runoff and drainage, including pollutants transported in stormwater, from surface mining areas and other active industrial areas would be controlled by stormwater drainage channels, swales, berms, silt fences, sediment ponds, revegetation, hay bales, or other erosion control measures, to ensure that surrounding land and water resources are protected from erosion, gullying, sedimentation and contamination.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-30 ESA / D201901577.01
Draft EIR July 2022
The combination of planned drainage, revegetation improvements, and management of active mining areas and stockpiles, as well as routine inspection, monitoring, and implementation of corrective actions, such as rill repair or expansion/repair of drainage systems, would control erosion and the transport of sediment or other pollutants in stormwater during mining and reclamation phases. Erosion control methods would be designed to handle runoff from not less than the 1-hour, 20-year intensity storm event. Sediment basins proposed in the mining pits would be designed to accommodate the 24-hour, 100-year storm event and be sized sufficiently such that no discharge of stormwater off-site to Sargent Creek or other receiving waters from mining areas occurs. Implementation of the measures contained in the Hazardous Material Business Plan and Spill Prevention Control Counter Measure Plan (see Section 3.9, Hazards and Hazardous Materials) would further reduce potential water quality impacts associated with hazardous materials and other potential pollutants associated with industrial activities. Consistent with the SWPPP (Appendix I.4) and the Reclamation Plan (Appendix B), any necessary erosion control measures and expansion, maintenance, or repairs of drainage control facilities needed to prevent erosion or degradation of downgradient receiving waters would be completed each year prior to the start of the rainy season.

Compliance with the requirements of the NPDES Industrial Permit, including the implementation of associated BMPs as part of the SWPPP, as well as the requirements of SMARA and County Use Permit related to mining and reclamation, would prevent the discharge of pollutants to surface waters or groundwater and minimize or eliminate degradation of surface water or groundwater quality during operation and reclamation of the Project. Impacts relating to the violation of water quality standards, waste discharge requirements, or the degradation of surface and/or groundwater quality due to operation and reclamation of the proposed Project would therefore be less than significant.

Mitigation: None required.

Significance after Mitigation: Less than significant
_________________________
Impact 3.10-3: The Project would not substantially decrease groundwater supplies through affecting groundwater quality such that the Project may impede sustainable groundwater management of the basin. (Less than Significant)
This impact discussion corresponds to Significance Criterion (b) (see Section 3.10.4.2) and addresses whether the Project would substantially decrease groundwater supplies by adversely affecting groundwater quality such that the Project may impede sustainable groundwater management of the basin.

Construction
Project construction would not require deep excavation, because the processing plant and other facilities would be at grade, and no basements or deep utility lines would be installed. Therefore, construction activities would not affect groundwater, and there would be no impact.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-31 ESA / D201901577.01
Draft EIR July 2022
Operation and Reclamation
Mining
Groundwater appears to occur beneath the Project site as a shallow groundwater table and also may be perched in fractures and granular landslide deposits. Surface features (spring and riparian areas) and groundwater seepage encountered above the maximum depth of mining in five exploratory soil borings in the Phases 1 and 2 pits suggest a shallow groundwater table.

Groundwater would enter the mining pits as seepage where the pits extend below the elevation of the water table or the perched water. This condition would likely occur in the Phases 1 and 2 pit because, unlike Phase 3 and 4, this pit would be a closed depression that could not be configured to drain by gravity to a nearby stream. Groundwater seepage and surface runoff into the pit would accumulate until it is balanced by evaporation, evapotranspiration, and groundwater outflow (Appendix I.2). Substantial volumes of groundwater accumulation in the Phases 3 and 4 pits would be unlikely because groundwater is deeper, as evidenced by the absence of seepage in the exploratory borings drilled in this area (SGS 2017). If seepage from perched water emanated from the western slope of the Phase 3 pit, it would likely be captured by the drainage swale that is proposed along the 300-foot elevation contour of the west quarry slope.

The Reclamation Plan prescribes actions that would be implemented if the groundwater seepage from the water table or perched groundwater accumulates in the mining pits and wet mining techniques (see Mining Below the Groundwater Table in Section 2.4.1, Overview) would be required. Wet mining techniques would involve a dragline crane or excavator that would retrieve harvested sand and gravel material from below the water that accumulates on the mining pit floor to a depth of 45 feet. Deadman-pulley systems would be used to harvest sand and gravel from approximately 45 to 90 feet below the water surface.

Wet mining techniques could expose the accumulated groundwater to potential water quality degradation and evaporation. The use of heavy equipment (e.g., dragline cranes and excavators) could increase the potential for residual grease, hydraulic oils, and fuel from the equipment to be introduced into the groundwater. Groundwater containing oils and grease, or other chemicals could percolate through the mining pit to eventually reenter the shallow groundwater table that flows out to the Pajaro River. Disturbance of the sediments below the water surface could cause high turbidity that would increase the concentration of total suspended solids (TSS) and total dissolved solids (TDS). Groundwater accumulated in the mining pits would be exposed to evaporation during mining and throughout reclamation, which could, over time, substantially reduce the volume of groundwater that would otherwise flow to the Pajaro River to recharge the Llagas Subbasin.

The potential for long term degradation and evaporation of the shallow groundwater wet mining techniques is low because the Project proposes BMPs to minimize surface water contamination and reduce evaporation. Chapter 7 of the Industrial SWPPP prepared for the Project identifies potential pollutants and several BMPs that would be implemented during work in the mining pit to minimize the potential for petroleum-based contaminants from entering the water within the mining pits (Appendix I.4). Examples of these BMPs include:

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-32 ESA / D201901577.01
Draft EIR July 2022
• All heavy earth moving quarry equipment requiring major rebuilding would be repaired offsite. • All heavy earth moving quarry equipment requiring routine maintenance would be serviced by the mobile field truck, which follows good housekeeping practices and BMPs, including carrying absorbents, absorbent pads and drip pans.
• Leaks from vehicles would be promptly repaired; and drip pans and absorbent materials used, as needed, temporarily until leakage is repaired.
• Spill kits would be available at all service areas.
• Hazardous materials and fuels would be stored in designated areas with secondary containment.

Standing water in the pits that is disturbed by drag line mining would become turbid and could increase the sediment load in the water column. However, the sediment suspended in the pit water would eventually settle out to the pit bottom and would not reenter the groundwater system.

Ponded groundwater that remains in the pits following mining and reclamation would be covered with at least 20 feet of overburden or other imported fill to bury and cap the groundwater, so no long-term evaporation occurs (see Section 2.4.1, Overview).

In summary, if mining operations intersect the shallow water table or perched groundwater and mining below the groundwater is required, the implementation of BMPs would reduce the potential for water quality degradation and covering ponded water with overburden would reduce evaporation. Therefore, this impact would be less than significant.

Access Roads, Processing Plant, Conveyor Belt, Rail Spur Subsurface activities would be limited to mining activities in Phase 1 pits. Therefore, there would be no impact on groundwater from these components.

Mitigation: None required.

Significance after Mitigation: Less than significant
_________________________
Impact 3.10-4: Project activities would not have an adverse impact on groundwater production in local groundwater wells. (Less than Significant) This impact discussion corresponds to Significance Criterion (b) (see Section 3.10.4.2) and addresses whether the Project would substantially decrease groundwater supplies such that it would adversely affect local well production.

Construction
Project construction, which is expected to require 9 months to complete, would use water for dust suppression. The amount of water used on a daily basis during the temporary construction period would only be a fraction of that required daily by Project operations (see Chapter 2, Project

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-33 ESA / D201901577.01
Draft EIR July 2022
Description, Table 2-4). Operations include aggregate washing (76,800 gallons), processing plant dust suppression (155,000 gallons), access/maintenance road dust suppression (3,000 gallons) and mining area dust suppression (3,000 gallons). As discussed below, the amount of groundwater pumping during operation would not substantially alter operation of other local wells, so the impacts on groundwater production due to the temporary use of groundwater during construction activities would be less than significant.

Operation and Reclamation
Mining
The mining areas are elevated hillsides, and the proposed quarry pits are not located within identified groundwater recharge basins. During mining, rainwater would be captured within the mining areas and allowed to percolate into soils (as described in Section 3.4, Biological Resources). Drainage from outside the mining areas would percolate into the ground and would be directed to area creeks. Changes in groundwater flow in the mining pit areas would be roughly proportional to the depth of the pit and area of disturbance. Thus, groundwater flows in the mining areas would tend to increase incrementally throughout the period of active mining, and the post‐mining changes would be similar to those at the end of the active mining period.

Given the limited change to percolation patterns overall, the impact to area wells as a result of mining activities would be negligible. As the quarry pits are not connected to groundwater basins (see Section 3.10.3.1), quarrying activities would have a less-than-significant impact on groundwater production at wells in the vicinity of the Project site.

Access Roads, Processing Plant, Conveyor Belt, Rail Spur Subsurface activities would be limited to mining activities in Phase 1 pits (discussed below).

However, Project operation would require groundwater for processing and dust control. The Project would be supplied by a well near the processing plant, west of the railroad tracks and south of the U.S. 101 overpass. Pumping would cause a drawdown (lowering) of groundwater levels near the well. Drawdown would decrease with distance from a pumping well, but a large decline in water level could potentially impact the operation or yield of affected nearby wells. For this analysis, the amount of drawdown has been estimated based on the pumping rate of the Project well, the distance to the nearby well, and the hydraulic characteristics of the aquifer.

As discussed above in Section 3.10.3.3, Groundwater Resources, there are several other groundwater production wells in the vicinity of the Project site. The closest wells belong to the Applicant, Valley Water, and a neighboring landowner (Sun and Sons LP). The Sun and Sons LP well is the closest (690 feet away) privately owned irrigation supply well to the Project site.

These wells could all experience water level decline due to Project pumping.

The annual water production from the Project supply well would be 82.3 acre-feet per year (AFY). Most of the water would be used for aggregate washing, and groundwater extraction for that purpose would be proportional to the rate of processing. Although processing could vary from year to year, it is assumed for this analysis to occur at a constant rate throughout the 30‐year

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-34 ESA / D201901577.01
Draft EIR July 2022
mining period.8 Within a given year, water use would occur almost exclusively during the 310 days that the plant operates. Wells are generally constructed to produce a target volume operating 50 percent of the time or less. Assuming a 12‐hour‐on, 12‐hour‐off pumping cycle during plant operation days, the pumping rate of the well would be 120 gpm.

When a production well is pumping, it draws the water down in a radial area around the well forming what is referred to as a cone of depression (used synonymously herein with drawdown cone). The formation of this drawdown cone is a function of time and distance, which can be estimated mathematically. Key parameters in the equation are aquifer transmissivity9 and storativity.10 Estimates of those characteristics were obtained from a calibrated regional groundwater flow model, which determined that drawdown at the Sun and Sons LP irrigation well, at the end of the 12‐hour pumping cycle, is estimated to be 0.8 to 4.0 feet. A repeating sequence of pumping cycles results in slightly greater drawdown and the estimated drawdown at the end of the 12‐hour pumping cycle the fifth day would be 0.9 to 5.6 feet.

In large groundwater basins shared by many users, it is normal for the cones of depression that form at individual wells to intersect those at neighboring wells; most or all wells routinely cause drawdown at neighboring wells. Drawdown caused by a new neighboring well would not cause a significant groundwater impact unless it would cause pumping water levels to drop below the top of the well screen.11 When that occurs, water can cascade into the well, entraining air and creating a risk of cavitation inside the pump (bubbles generated by low pressure). This can damage the pump, resulting in a costly repair and interruption of water supply (Appendix I.2).

Well construction information is not available for the private (Sun and Sons LP) irrigation well closest to the Project’s proposed supply well. However, drillers’ logs for other wells in the area indicate that a typical depth to the top of the well screen is 100 feet and a typical total well depth is 400 feet. Groundwater level data from the Valley Water monitoring well during 2012–2015 indicate that water levels recovered during the winter each year to 9 feet below ground surface, which probably corresponds to the elevation of the nearby Pajaro River. In summer, water levels declined to 25 feet below ground surface in 2012 (normal year) and 45 feet below ground surface in 2014 and 2015 (critical dry years). Thus, the lowest static (non‐pumping) water level in a dry year was 55 feet above the top of the screen.

During pumping, water levels drop below the static water level by an amount proportional to the specific capacity12 of the well. Specific capacity data are not available for the potentially impacted Sun and Sons, LP irrigation well, but the relatively close spacing of the neighbor’s 8 This analysis applies the proposed constant pumping rate rather than the peak annual use because the constant rate better reflects groundwater extraction rates for the analysis of drawdown. This approach is consistent with that applied by Todd Groundwater (Appendix I.2).
9 Transmissivity is the rate at which water is transmitted through the water-bearing sediments or rocks (Wilson and Moore 1998)
10 Storativity is the amount of groundwater in water bearing sediment or rocks releases or takes into to storage (Ibid.) 11 The well screen is that section of well casing that is perforated to allow water to enter the well from the waterbearing strata (sediments or rock). The well screen extends horizontally across the thickness of the strata while a solid, non-perforated casing extends across strata that is not water bearing. 12 Specific capacity is the expression of the productivity of a well obtained by dividing the rate of discharge (pumping rate) by the drawdown of a well.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-35 ESA / D201901577.01
Draft EIR July 2022
irrigation wells suggests that they have relatively low yields. Based on other wells in the region for which data are available, reasonable estimates of pumping rate and specific capacity might be 400 gpm and 10 gallons per minute per foot of drawdown, respectively. Those values indicate a pumping drawdown of 40 feet. Combining that drawdown with 1 to 6 feet of drawdown from the Project well would still leave 9 to 14 feet of water above the top of the well screen at the end of the irrigation season in a dry year. Therefore, the drawdown impact would be less than significant. Because drawdown decreases with distance, it would also be less than significant at the other nearby production wells belonging to the Applicant, Valley Water, and Sun and Sons LP (see Section 3.10.3.3).

Mitigation: None required.

Significance after Mitigation: Less than significant
_________________________
Impact 3.10-5: The Project would not substantially increase regional consumptive use of groundwater or reduce recharge, thereby decreasing availability of groundwater. (Less than Significant)
This impact discussion corresponds to Significance Criterion (b) (see Section 3.10.4.2) and addresses whether the Project would substantially decrease groundwater supplies.

Construction
Project construction would use water for dust suppression. The amount of water used daily during the temporary construction period would only be a fraction of that required daily by Project operations (see Chapter 2, Project Description, Table 2-4). Operations include aggregate washing (76,800 gallons), processing plant dust suppression (155,000 gallons), access/maintenance road dust suppression (3,000 gallons) and mining area dust suppression (3,000 gallons). As discussed below, the amount of groundwater pumping during operation would not substantially alter operation of other local wells, so the impacts associated with increased regional consumptive use during construction activities would be less than significant.

Operation and Reclamation
Mining Pits, Access Roads, Processing Plant, Conveyor Belt, Rail Spur Consumptive use refers to the amount of applied water used and not available for reuse as a source of supply. It includes water that evaporates, transpires, or is incorporated into products, plant tissue, or animal tissue (DWR 2021). Effects on the regional groundwater balance and on groundwater availability to other users depend on the net result of changes in recharge13 and consumptive water use by the Project. Consumptive use would change only during the mining period, but recharge would change during and after the mining period. Consumptive use of groundwater would increase during the 30‐year mining period by approximately 83 AFY, which is the projected annual volume of water extracted from the Project supply well. During Project 13 Recharge refers to the replenishment of groundwater bearing strata through infiltration of surface water.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-36 ESA / D201901577.01
Draft EIR July 2022
operation, recharge may increase slightly because existing grass and trees would be replaced by mining pit walls consisting of bare rock and soil, reduced plant evapotranspiration,14 and rainfall runoff captured in the pits would infiltrate, especially as the pits reach their full size. While it may be the case that recharge could increase during the operation of the Project, this analysis conservatively assumes that recharge would remain unchanged, and that regional groundwater consumptive use would increase by 83 AFY.

Because the Project supply well is next to a perennial15 reach of the Pajaro River, where the river receives flow from groundwater discharge from the Bolsa and Llagas subbasins, the pumping would tend to deplete river flow, up to a rate equal to the average annual pumping rate (83 AFY).

Groundwater users in the Llagas Subbasin in Santa Clara County and the Bolsa and San Juan Valley subbasins in San Benito County would be unaffected from a water balance standpoint because they are upgradient of the Project well and impacted river reach. Water users most likely to be affected would be downstream in the Pajaro Valley near Watsonville, where groundwater pumping averaged 52,000 AFY during 2009–2013 (Appendix I.2). If all consumptive use at the Project site was considered a reduction in river percolation and groundwater recharge in the Pajaro Valley (rather than a decrease in outflow to the ocean), it would amount to approximately

0.2 percent of total Pajaro Valley pumping. At that magnitude of change, Project groundwater pumping would result in a minor increase to regional consumptive use, and downstream water demand could still be met. Therefore, this impact would be less than significant.

Mitigation: None required.

Significance after Mitigation: Less than significant
_________________________
Impact 3.10-6: The Project would not impede sustainable groundwater management of a groundwater basin. (Less than Significant)
Construction
Project construction would use water for dust suppression. The amount of water used on a daily or annual basis would be substantially less than required by Project operation. As discussed below, the amount of groundwater pumping during operation would not substantially alter operation of other local wells and thus would not adversely affect the management of the groundwater basin. Therefore, this impact would be less than significant.

Operation and Reclamation
Mining, Access Roads, Processing Plant, Conveyor Belt, Rail Spur The annual water production from the Project supply well would be approximately 83 AFY.

Although processing could vary from year to year, it is assumed for this analysis to occur at a 14 Evapotranspiration refers to the loss of water from a land area Water that is transpired by plants during photosynthesis.
15 Refers to a stream that flows throughout the year.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-37 ESA / D201901577.01
Draft EIR July 2022
constant rate throughout the mining period.16 The Project supply well would be located at the downgradient tip of the Llagas Subbasin, which is the Santa Clara County part of the GilroyHollister Groundwater Basin. Because of this location and the proximity to a perennial reach of the Pajaro River, the primary effects of Project pumping on basin yield would accrue to downstream groundwater users by means of changes in river percolation. The primary downstream water user group is groundwater pumpers in the Corralitos Basin located on the coastal plain surrounding Watsonville. River percolation supplies approximately 30 percent of average annual recharge to the Corralitos Basin. The consumptive use for Project operation of 83 AFY would amount to 0.2 percent of the average annual groundwater pumping in the PVWMA area and would be negligible in the context of other much larger sources of variability (Appendix I.2). The change in post‐mining net consumptive use due to changes in vegetation in the pits and along downstream reaches of Sargent Creek would be similarly small, especially considering that no substantial impervious area is proposed.17 Therefore overall infiltration of water into soils below would not substantially change. Furthermore, approval of the Project groundwater well would require confirmation from Valley Water, as the Groundwater Sustainability Agency, that the well would not be inconsistent with the groundwater management plan, per Executive Order N-7-22. The Project would therefore not substantially reduce groundwater supplies or impede sustainable groundwater management of the basin, and the localized impact would be less than significant.

Mitigation: None required.

Significance after Mitigation: Less than significant
_________________________
Impact 3.10-7: The Project would not substantially alter existing drainage patterns in a manner that would result in substantial erosion or siltation on or off site, increased runoff, or adverse impacts on water quality or related to flood flows. (Less than Significant) This impact discussion corresponds to Significance Criteria (c[i–iv]) (see Section 3.10.4.2) and addresses whether the Project would substantially alter the existing drainage pattern of the site or area in a manner that would result in substantial erosion or siltation on or off site, increased runoff, or adverse impacts on water quality or related to flood flows.

Construction
Water quality impacts, including those associated with erosion and sedimentation of on- and offsite receiving waters due to stormwater runoff, would be less than significant for construction activities associated with the proposed processing plant, mining areas, overburden stockpile area, access road improvements, conveyor belt, and rail spur for the following reasons. As described 16 The groundwater analysis for this impact (Appendix I.2) applied the proposed constant pumping rate rather than the peak annual use because, while not an average, the constant rate better reflects groundwater extraction rates for the analysis of drawdown.
17 The processing plant and access roads would create some ground area that may restrict surface water infiltration and ultimately groundwater recharge but the total area of these facilities represent only a small fraction of the total area available to recharge and thus would affect recharge only negligibly if at all.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-38 ESA / D201901577.01
Draft EIR July 2022
under Impact 3.10-1, above, implementing actions and BMPs required under the Construction General Permit, as well as proposed measures outlined in Chapter 2, Project Description, relating to stormwater drainage (Section 2.4.3 and Section 2.6.5) and erosion control (Section 2.4.4), would prevent significant water quality impacts related to erosion and the transport of sediment in stormwater associated with construction activities.

Operation
Processing Plant, Conveyor Belt, Rail Spur, and Access Roads Water quality impacts, including those associated with erosion and sedimentation of on- and offsite receiving waters due to stormwater runoff, would be less than significant for the proposed processing plant, mining areas, overburden stockpile area, access road improvements, conveyor belt, and rail spur, because as described under Impact 3.10-2, above, implementing actions and BMPs required under the NPDES Industrial Permit and associated industrial operations SWPPP (Appendix I.4), as well as proposed measures outlined in Chapter 2, Project Description, relating to stormwater drainage (Section 2.4.3 and Section 2.6.5) and erosion control (Section 2.4.4), would prevent significant water quality impacts related to erosion and the transport of sediments in stormwater associated with operation activities, with the exception of the realignment of drainage channels in the mining areas and at the creek crossings (assessed in detail below).

Proposed Drainage Alterations (Tar Creek Crossing, Mining Phases 1-4, and Sargent Creek Crossing)
Realigning existing ephemeral drainage channels within the watershed, routing surface waters through culverts, and altering creek channels are proposed as part of the Project to route stormwater flows from upgradient watershed areas around active mining phases and increase site access and safety (Figure 2-15). Such realignments and channel alterations are proposed for the proposed bridge over Tar Creek (Figure 2-13) and flood plain realignment berms (Figure 2-14), the Sargent Creek access road crossing (see figure on p. 9 of Appendix I.1), and the channels and culverts designed to reroute drainages associated with mining Phase 2/Permanent Overburden Stockpile Area (Figure 2-16) and Mining Phase 3 (Figure 2-17). Altering drainage patterns such that channels follow a new course or are conveyed through culverts or narrowed channels, could concentrate flows from off-site or upgradient areas and result in an increase in flow depth and/or flow velocity in on-site or downstream watercourses. Increased depth and velocity within realigned channels or at the downstream discharge point of culverts and road crossings could increase the potential for the channel bed and bank to erode and mobilize bed and bank sediments. If the increase in velocity is large enough and ample sediment is available for transport, the resultant bed/bank erosion and increase in sediment transport could be substantial, negatively impacting both channel stability and water quality on-site and downstream.

The Flood and Drainage Analysis (Drainage Study) prepared for the Project (Appendix I.1) included a detailed review of the hydrologic characteristics of the Project site. Model analyses were conducted to quantify changes to runoff rates and flood limits from implementation of the Project and to provide design recommendations for the proposed drainage improvements to safely convey stormwater and flood flows without resulting in significant impacts relating to scour, sediment

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-39 ESA / D201901577.01
Draft EIR July 2022
transport and water quality. The model results were incorporated into the engineering design for the proposed creek crossings, culverts, channel realignments, and flood berms. The resulting proposed stormwater management system comprises of a network of swales, inlet controls, energy dissipation structures, and erosion control features to prevent erosion and scour of channel bed/bank, facilitate infiltration, and attenuate peak runoff rates in a manner that mimics predevelopment hydrologic conditions at the Project site for downgradient receiving waters.

Sutro Science, the County’s environmental consultant, independently reviewed the hydrologic study for accuracy and to verify that methodologies and assumptions employed were appropriate and that the results were valid (Sutro Science 2020). Where applicable, the results and findings of the hydrologic study are incorporated into the analysis of the Project’s potential environmental impacts. Discussed below is a summary of the model analysis methodology and assumptions employed for the Drainage Study followed by an assessment of the Project’s environmental impacts for each of the proposed elements based on the Drainage Study results.

Methodology and Assumptions
Hydrologic analysis included Sargent Creek and Tar Creek in the vicinity of the described drainage improvements and creek crossings, as well as at locations where other smaller drainage areas contribute flows that enter the proposed Project site. All the proposed conveyance structures and creek crossings were designed to safely convey flows associated with the 100-year storm event.

As described in Section 3.10.3.2, Surface Water Resources, an impoundment of Sargent Creek exists about 2,000 feet upstream of the proposed Phase 3 and Phase 4 quarry access road that crosses Sargent Creek. This impoundment entirely retains normal season upstream flow. As a result, there is no flow within Sargent Creek downstream of the impoundment for much of the year, except when flows south of the impoundment are contributed directly to the creek via sheet flow or from smaller ephemeral drainage channels that flow into Sargent Creek downstream of the impoundment. The model analysis conducted for the Drainage Study assumed that the pond upstream of the impoundment was full and no additional storage capacity would be available.

This assumption represents a worst-case (i.e., most conservative) scenario incorporating conditions for a100-year event conservatively occurring during an El Niño type wet winter where sufficient rain has fallen prior to the 100-year event to have filled the impoundment.

The Drainage Study analysis and design recommendations are consistent with the Santa Clara County Drainage Manual (drainage manual) (County of Santa Clara 2007), which requires a channel to be designed to safely convey a 10-year storm event with 1 foot of freeboard. The proposed Tar Creek bridge has been designed to convey the stormwater from the 100-year storm event (a larger storm than the 10-year event) safely under the bridge with 0.7 foot of freeboard (i.e., exceeding the requirements of the drainage manual). To estimate peak discharges, the Unit Hydrograph Method was used. WIN TR-55 software developed by the Natural Resources Conservation Service (NRCS) was used to determine runoff rates based on the SCS Curve Numbers. TR-55 is the standard model used for such assessments and can simulate a wide variety of surface conditions, land-use changes, and the subsequent effect on stormwater runoff rates, volumes, and storage capacity.

TR-55 also is suitable for modelling complex drainage networks and stormwater management systems such as the one proposed as part of the Project.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-40 ESA / D201901577.01
Draft EIR July 2022
Accurate hydrologic modelling requires rainfall characteristics that are representative of the study area. For stormwater control and mitigation, the storm duration and intensity for stormwater system design was determined from the Santa Clara County Mean Annual Precipitation Isohyets Map and Intensity-Duration-Frequency Curves (Appendix I.1). To design a system consistent with regulatory requirements, the model analysis included consideration of the rainfall depths and associated runoff from the 100-year, 24-hour storm (6.96 inches) to determine peak runoff rates and total volume generated during design storms.

The latest HEC-RAS version 5.0.7 software was used to model flows in Tar Creek and Sargent Creek. Cross-sections of the Tar Creek and Sargent Creek were imported from AutoCAD Civil 3D. Drainage design sizing was performed using the AutoCAD Hydroflow Express Extension, which utilizes Manning’s Equation. The USGS 7.5-minute maps and Aerial Survey were used to determine the tributary watershed areas for the site. Tributary areas to Sargent and Tar Creeks were divided into smaller subareas (see Table 1 in Appendix I.1). All hydrologic calculations and further details regarding the model methodology are provided in the Drainage Study (Appendix I.1).

Tar Creek Bridge and Floodplain Realignment
The 100-year calculated flood limits of Tar Creek extend approximately 350 feet south into the proposed processing plant site (Figure 3B Appendix I.1). To prevent the flood limits from encroaching into the plant site, a 5-foot-high berm is proposed between the southern bank of Tar Creek and the boundary of the processing plant, and a 4-foot-high berm is proposed on the north side of Tar Creek to channel the flows under the proposed bridge (Figure 3C in Appendix I.1).

The proposed berms would be armored against scour with rip-rap. The proposed Tar Creek bridge is located just north of the downstream terminus of Tar Creek.

Tar Creek Velocity Changes
The existing velocities in the vicinity of the proposed bridge vary from 2.5 to 3.6 feet per second with existing floodplain widths ranging from 500 feet to 800 feet. The model analysis determined that installation of the berms and the new flood plain boundary would decrease velocities by approximately 0.5 to 1.0 feet per second upstream of the bridge as compared to existing conditions. The reduction in velocities upstream of the bridge mean that the bridge would create a backwater during storm events exceeding a 5-year event. In the vicinity of the processing plant site (i.e., downstream of the bridge), the velocity would increase by 0.3 to 1.9 feet per second as compared to existing conditions. The proposed and existing velocities would be identical at the downstream limit of the plant before Tar Creek reaches the existing culvert under the railroad track and U.S. 101.

Flood Depth
Based on the Drainage Study analysis, the proposed floodplain realignment would affect the flood limits of Tar Creek and water surface elevations associated with the 100-year event only in the vicinity of the plant. The existing 100-year water surface elevations vary from 162.7 feet msl to 158.9 feet msl flowing approximately 2 to 3 feet deep at the northern edge of the proposed plant site. Installation of the berms and the new flood plain boundary would result in an increase of water surface elevation by about 0.8 to 1.0 feet for a distance of 300 feet upstream of the bridge.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-41 ESA / D201901577.01
Draft EIR July 2022
The depth of flow along the berm protecting the processing plant site would be 3 feet, leaving approximately 2 feet of freeboard to the top of the berm. At 300 feet upstream of the bridge, the 100-year water surface elevation would be 0.6 feet higher than the existing elevation, and at 700 feet upstream, the proposed and existing water surface elevation would be identical. There are no developed structures upstream of the plant. In the vicinity of the processing plant site (i.e., downstream of the bridge) the water surface elevation would rise by approximately 0.2 to 1.1 feet as compared to existing conditions. The proposed and existing water surface elevations would be identical at the downstream limit of the plant, upstream of where Tar Creek reaches the existing culvert under the railroad track and U.S. 101. The bridge and associated access road would be constructed above the 100-year flood elevation. The bridge is designed to convey the 100-year flood flow with 0.7 feet of freeboard, exceeding the drainage manual requirement that the 10-year event (a smaller event) must be conveyed with 1 foot of freeboard.

Tar Creek Scour, Sediment Transport, and Water Quality
Sediment transport analysis was performed for Tar Creek to determine the effect of the proposed floodplain realignment on water quality at the downstream end of the creek before the outfall to Carnadero Creek and, ultimately, the Pajaro River. Sediment transport was calculated in tons per day upstream and downstream of the proposed bridge where the bridge and berms would affect the width and depth of the floodway to the greatest degree. The pre- and post-development values are based on the average velocities, depth of flow, and width of the floodplain. The sediment transported by the floodway upstream of the bridge would decrease under the post-development conditions due to a decrease in velocities caused by the bridge constricting the floodway. Sediment transport would also decrease downstream of the bridge at the plant site due to the decrease in the width of the flood plain, which would reduce the scour surface area of the floodplain. By armoring the berms and bridge piers against scour, the sediment loading at those locations would be lessened, providing an additional reduction in floodway surface area from scour and sediment transport (Table 3.10-2).

TABLE 3.10-2

TAR CREEK SEDIMENT TRANSPORT FOR PRE- AND POST-DEVELOPMENT CONDITION Attribute
Existing Proposed
Upstream of
Tar Creek
Bridge
Downstream
of Tar Creek
Bridge
Upstream of
Tar Creek
Bridge
Downstream
of Tar Creek
Bridge
Average Width Floodplain (ft) 213 610 222 412
Average Depth of flow (ft) 11.7 10.7 11.7 11.0
Average Velocity (feet per second) 6.5 3.7 6.3 4.2
Sediment Transport (tons/ft/day) 707 158 671 222
Sediment Transport (tons/day) 150,261 96,444 148,787 91,355 Total Sediment Transport (tons/day)1 247,000 240,000
NOTES:

1. Totals vary due to rounding.

SOURCE: Appendix I.1

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-42 ESA / D201901577.01
Draft EIR July 2022
A similar scour analysis was conducted for the proposed bridge abutments and piers to determine the necessary rip-rap reinforcement to prevent erosion of the channel bed and bank. Based on the calculations (Appendix I.1), the minimum size rip-rap reinforcement for the bridge piers required to prevent scour and erosion of the channel is 7-inch rock size placed to a thickness of 2-foot depth to a distance of 5 feet around the perimeter of each pier. As proposed, the Project would provide greater than the minimum necessary protection against scour: 12-inch rip rap would be used for 6 feet around the perimeter of each pier. The rip-rap reinforcement for the bridge abutments would consist of 12-inch rock placed at a thickness of 1.2 feet and extending 7.6 feet horizontally, 6 feet vertically, and 25 feet downstream of the abutments (see Section 4.2.1 in Appendix I.1 for engineering drawing). Due to the rip-rap placement along the berm protecting the quarry processing plant site, the post-development scour and sediment transport also would be reduced through the section of the creek where the berms are installed when a 5-year storm event or greater occurs. The storm events below a 5-year event would pass within the bridge span and stay in the creek bed without a change in scour between existing and proposed conditions.

Phase 1 and 2 Mining Area
The Phase 1 and 2 mining area would be located west of the proposed processing plant site. As described in Section 3.10.3.2, Surface Water Resources, there is an existing ephemeral drainage channel associated with the Phase 2 mining area. The existing channel is proposed to be rerouted around the perimeter of the Phase 2 mining area and through the Permanent Overburden Stockpile Area (Figure 2-16). Flows would be conveyed within a 36-inch culvert for a portion of the realignment. The culvert would extend southeast under the proposed access road and discharge at an existing natural drainage depression (i.e., the same downstream discharge point under pre-development conditions).

Based on the Drainage Study, 100-year flow within this drainage is 86 cubic feet per second (cfs) under pre-development conditions. The depth of flow would be 3 feet in the culvert. The flow through the culvert would be inlet controlled and the velocity in the culvert would be 12.4 feet per second. To address increased velocities at the culvert outlet and avoid scour of the channel bed and bank, a rock apron would be installed using 18-inch rock in a layer 2 feet thick placed for 25 feet downstream of the outlet or twice the depth of flow. The rock would protrude above the flowline of the channel to dissipate the energy of the flow and reduce velocity downstream of the culvert the outflow. Therefore, increased velocities would not result in substantial erosion or scour of the bed or bank of the channel on-site or downstream.

Phase 3 and 4 Mining Areas
The Phase 3 and 4 mining areas are located in the southern portion of the mining site. No drainage channels are proposed for re-alignment for the Phase 4 pit (see Impact 3.10-2, above, for an assessment of impacts relating to stormwater drainage and erosion control during mining operations). As described in Section 3.10.3.2, Surface Water Resources, an ephemeral drainage channel that is tributary to Sargent Creek runs upland and through the Phase 3 area. As part of the Project, the channel section within the Phase 3 mining area would be realigned around the perimeter of the area into a new 12-foot-wide and 2-foot-deep swale that would run along several benches on the northern side of the Phase 3 mining area at an elevation of 300 feet msl. The

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-43 ESA / D201901577.01
Draft EIR July 2022
proposed swale would discharge into an existing natural drainage swale on the east side of the mining area and continue under the access road via three 36-inch culverts, which would discharge into Sargent Creek just upstream of the location of the existing drainage swale discharge point into Sargent Creek (Figure 2-17).

A drainage area totaling 75 acres is tributary to the northwest portion of ephemeral channel upgradient of Phase 3. The 100-year flow is 186 cfs, according to the Drainage Study. Based on the model analysis presented in the Drainage Study, the proposed culvert outfall would not modify flow conditions in Sargent Creek from existing conditions in terms of flow depth or velocity for the 100-year event. As described for Phase 2 and Sargent Creek crossing, above, the outfall into Sargent Creek would be armored to protect the channel bed and bank against scour and erosion and a rip-rap apron would extend 25 feet downstream or for a distance two times the depth of flow with a calculated depth of flow in the culvert of 3 feet.

Sargent Creek Crossing
An arch culvert crossing is proposed for the access road connecting Phases 3 and 4 over Sargent Creek (Figure 2-10) to safely convey the flow for the 100-year intensity storm. The culvert would span the creek bed, leaving the channel bottom undisturbed, to convey flows in a more natural manner than a fully closed conduit (see engineering drawing in Section 4.1 of Appendix I.1). A low-profile culvert is proposed with a 35-foot span over the Sargent Creek natural channel bed and an 11-foot rise. Sargent Creek hydrologic characteristics were modeled from the northern upstream end of the creek to approximately 11,800 feet to the south for the pre- and postdevelopment condition (Figure 2B in Appendix I.1). Based on the Drainage Study, the existing 100-year flow in Sargent Creek at that location is 265 cfs. The velocity under existing (i.e., no crossing) conditions is 6.0 feet per second. Post-development, the culvert would increase the velocity in the channel to 8.2 cfs during the 100-year event.

The slopes and the inside edge of the culvert would be armored with rip-rap with the minimum length of the rip-rap apron being 25 feet or twice the depth of flow, whichever is greater, based on the engineering design recommended in the Drainage Study, to mitigate potential scouring from the increased post-development creek velocities at the culvert crossing during the 100-year event.

The outfall velocity of 8.2 feet per second would be reduced to the pre-development flow velocity of 6 feet per second downstream of the culvert a short distance, such as by the downstream end of the rip-rap apron or shortly thereafter. Post-development increased velocities associated with the 100-year storm event would affect only a small percentage of the total stream channel due to the length of the culvert being only 66 feet of the stream channel’s total length of 12,000 feet before it leaves the site and enters the Pajaro River. The proposed rip-rap apron would dissipate energy and prevent scour from causing significant erosion for 100-year flow events at the proposed crossing. The culvert would not alter post-development scour during storm events of lesser intensity than the 100-year event. After reclamation of the Phase 3 and Phase 4 areas has been completed, the Sargent Creek crossing would be removed, and the area disturbed for the maintenance road would be revegetated (or maintained for use for cattle operations). After the removal of the Sargent Creek crossings, Sargent Creek would be restored to its natural pre-Project condition.

For the above reasons, the operational impacts would be less than significant.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-44 ESA / D201901577.01
Draft EIR July 2022
Reclamation
Water quality impacts, including those associated with erosion and sedimentation of on- and offsite receiving waters due to stormwater runoff, would be less than significant for the proposed reclamation activities for the following reasons. As described under Impact 3.10-1 and Impact 3.10-2, above, implementing actions and BMPs required under the Construction General Permit and associated construction SWPPP, NPDES Industrial Permit and associated industrial operations SWPPP (Appendix I.4), the Reclamation Plan (Appendix B), as well as proposed measures outlined in Chapter 2, Project Description, relating to stormwater drainage (Section 2.4.3 and Section 2.6.5) and erosion control (Section 2.4.4), would prevent significant water quality impacts related to erosion and the transport of sediments in stormwater associated with reclamation activities.

Summary
The model analysis presented in the Drainage Study under the pre- and post-Project condition for each of the assessed channel realignments, floodplain realignment, and creek crossings show that the Project would not increase peak discharge rates and flood flow elevations associated with the 100-year storm in a manner that would result in substantial scour, erosion, or sediment transport on-site or downstream. The proposed drainage improvements would largely mimic the preProject hydrology of the site regarding peak flow rates and would slightly decrease overall the peak sediment transport associated with Tar Creek 100-year flows. As such, implementation of the Project would not result in substantial erosion or sediment transport or other hydromodificationrelated impacts on- or off-site, and the Project would not result in increased sediment being transported to downgradient receiving waters in a manner that would degrade receiving water quality or contribute to impairments for sediment and turbidity that have been determined for Carnadero Creek and the lower Pajaro River.

The Project design is consistent with applicable regulatory standards for and would not result in hydromodification-related impacts on-site or downstream. The proposed design elements for stormwater capture, conveyance, and routing are sized appropriately for calculated peak discharges associated with the required design storms. Additionally, the stormwater system has been designed, based on engineering and model analysis, to ensure channel and culvert stability for the 100-year/ 24-hour design storm. Impacts related to substantially altering the existing drainage pattern of a site or area, including through the alteration of the course of a stream or river, in a manner which would result in substantial erosion or sedimentation on- or off-site, increased runoff, or adverse impacts on water quality or related to flood flows would be less than significant.

Mitigation: None required.

Significance after Mitigation: Less than significant
_________________________

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-45 ESA / D201901577.01
Draft EIR July 2022
Impact 3.10-8: The Project would not risk release of pollutants due to Project inundation in a flood hazard zone, or due to impeding or redirecting flood flows. (Less than Significant) This impact discussion corresponds to Significance Criteria c(4) and (d) (see Section 3.10.4.2).

The Project site is not located near an ocean, bay, or other large body of water and would not be subject to inundation due to dam failure, tsunami, or seiche. As described in Section 3.10.3.2, Surface Water Resources, the Project site is not located within a designated 100-year flood hazard area. The Project site is located within FEMA Flood Zone D: areas in which flood hazards are undetermined, but possible. As described in Section 3.10.3.2, the 100-year flood limits of Tar Creek were calculated for the Project site (Appendix I.1). Based on the 100-year calculated flood limits of Tar Creek, the proposed processing plant is within an area at risk of inundation during a 100-year flood event. No other portions of the Project site are within an area at risk of inundation during a 100-year flood event and, as such, would not result in the release of pollutants due to flooding.

Construction and Reclamation
Because construction and reclamation of the proposed processing plant site would be short-term in nature and conducted primarily in the seasonally dry months when rainfall is not typical, floodrelated impacts are assessed for the operation phase of the processing plant site and associated access road.

Operation
Mining Pits, Access Roads, Conveyor Belt, Rail Spur
The proposed stormwater drainage, retention, and conveyance system is designed to accommodate 100-year, 24-hour precipitation conditions with sizing and capacity to safely convey storm flows associated with 100-year storm, including stormwater retention and sedimentation basins within the Phase 1 to 4 mining areas sized appropriately to contain stormwater generated within the active mining areas without discharge. Therefore, a 100-year storm event would not result in flooding and the subsequent release of pollutants due to inundation.

Processing Plant and Tar Creek Bridge
The 100-year flood zone derived for the Project is consistent with the 2007 Santa Clara Drainage Manual (County of Santa Clara 2007) hydrologic method for determining flows from a drainage area greater than 200 acres in area. The calculated 100-year flood limits of Tar Creek extend approximately 350 feet south into the plant site with surface elevations from 164.7 to 158.9 feet, representing flows approximately 2 to 3 feet deep at the northern edge of the plant site (Appendix I.1). Inundation of the processing plant during a 100-year storm event could result in the release of sediment and other industrial pollutants into downgradient receiving waters (i.e., Carnadero Creek and the lower Pajaro River), which are impaired due to various pollutants, including sediment (see Section 3.10.3.2, Surface Water Resources).

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-46 ESA / D201901577.01
Draft EIR July 2022
To prevent the flood limits from encroaching into the plant site, a 5-foot-high berm is proposed along the northern boundary of the plant with another 4-foot-high berm proposed on the north side of Tar Creek (Figure 2-14) and also improvements to bring the plant access road above the determined flood plain elevation. The proposed berms would channel flood flows associated with 100-year water surface elevations in Tar Creek under a 5-foot-wide, 70-foot-long proposed bridge. The design of the bridge is consistent with the requirements of the Santa Clara Drainage Manual, and would convey flood flows from a 100-year storm event with 0.7 feet of freeboard (Appendix I.1).

Engineering analysis conducted as part of Project design determined that, with the proposed berms, the water surface elevation would rise by about 0.8 to 1.0 feet for 300 feet upstream of the bridge during a 100-year storm event; in the vicinity of the plant site, the water surface elevation would rise by approximately 0.2 to 1.1 feet. The depth of flow along the berm protecting the plant site would be 3 feet leaving approximately 2 feet to the top of the berm. The berms would be armored with 12-inch rip rap to prevent scour. In addition, bridge abutments would be reinforced with 12-inch rock placed at a thickness of 1.2 feet and extending 7.6 feet horizontally, 6 feet vertically, and 25 feet downstream of abutments to prevent erosion and scour of the Tar Creek channel and bed. Therefore, the proposed berms would ensure that the processing plant would not be inundated during a 100-year storm event due to the realigned floodplain, and as such, pollutants would not be released as a result of site inundation due to flooding. Further, the design of the berms and Tar Creek Bridge ensure such features are stable under 100-year flood flows and would not be damaged, undermined, or fail in a manner that would result in inundation.

The 100-year water surface elevation would be 0.6 feet higher than the existing elevation at the plant and the proposed and existing water surface elevation would be identical 700 feet upstream of the plant site. There are no developed structures upstream of the plant within the reach of increased surface water elevations during the 100-year storm event; as such, increased surface water elevations during a 100-year storm event would not result in the release of pollutants due to inundation. The baseline and post-Project water surface elevations would be identical at the downstream limit of the plant, which is upstream of the location where Tar Creek reaches the existing culvert under the railroad track and U.S. 101 (Appendix I.1). Thus, the Project would not alter the flood risk potential downstream of Tar Creek Bridge or the potential for release of pollutants due to inundation by flood waters.

Access Road Improvements
There are two concrete box culverts approximately 700 feet apart that currently convey stormwater runoff from the west under Old Monterey Road. The existing concrete box culverts would remain in place as part of the proposed access road improvements. The southern culvert is 11 feet wide by 4 feet deep and conveys flows from Tick Creek. During a storm of 20-year intensity, Tick Creek carries a peak flow of 397 cfs. The culvert to the north is 5 feet wide by 4 feet deep and conveys flows from an unnamed drainage. During a storm of 20-year intensity, the unnamed channel north of Tick Creek carries a peak flow of 132 cfs.

The existing culverts that convey flows from Tick Creek under Old Monterey Road were assessed to quantify storm water flow rates tributary to Old Monterey Road and determine the capacity of

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-47 ESA / D201901577.01
Draft EIR July 2022
the existing water conveyance facilities (THA 2018). The drainage analysis is consistent with the methodologies and requirements of the County’s drainage manual (County of Santa Clara 2007).

Based on calculations presented in the Drainage Study, both culverts have capacity to convey storm flows associated with the storm of 20-year intensity, consistent with the drainage manual.

During a 100-year event, storm flows would exceed the capacity of both culverts and overtop Old Monterey Road and continue to flow east, as occurs under existing conditions. The quarry would not operate during the 100-year storm event, or during events greater than 0.5 inches of rainfall, and Old Monterey Road would not be used to access the site during a flood event for safety reasons. Additionally, the rehabilitated roadway would be installed at a higher elevation than the existing road and would be constructed to current code, increasing stability and reducing the potential for erosion or washout, and reducing the potential for an associated release of pollutants due to inundation by 100-year flood flows.

Summary
The design of the proposed flood protection berms, access road improvements, and access road bridge over Tar Creek would prevent inundation of Project facilities from flooding events with a 100-year return period and would avoid inundation or washout of Project facilities, ensuring no release of pollutants on-site or off-site as a result of a 100-year flood event. The proposed stormwater drainage, retention, and conveyance system within the proposed processing plant is designed to accommodate 100-year, 24-hour precipitation conditions with sizing and capacity to safely convey storm flows associated with 100-year storm. As assessed under Impact 3.10-2, Project implementation would not substantially alter drainage patterns in a manner that would result in significant impacts related to erosion or increasing the rate or amount of surface runoff.

Run-on from adjacent drainage areas would be conveyed around the active mining areas and stormwater discharge volumes and rates would not substantially increase as a result of the Project. In addition, as discussed under Impact 3.10-2, on-site hazardous materials would be placed inside secondary containment structures, a Hazardous Material Business Plan and Spill Prevention Control Counter Measure Plan are included in the Project (see Section 3.9, Hazards and Hazardous Materials), and implementation of the Industrial SWPPP would require inclusion of numerous BMPs related to the storage, processing and handling of hazardous materials and other potential pollutants, minimizing the risk that pollutants would become mobilized as a result of inundation of the processing plant area. Impacts related to impeding or redirecting flood flows or the release of pollutants from inundation by flood waters or exceeding proposed or existing stormwater conveyance systems would be less than significant.

Mitigation: None required.

Significance after Mitigation: Less than significant
_________________________
Impact 3.10-9: The Project would not conflict with the CCRWQCB Basin Plan or obstruct implementation of a sustainable groundwater management plan. (Less than Significant) This impact discussion corresponds to Significance Criterion (e) (see Section 3.10.4.2).

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-48 ESA / D201901577.01
Draft EIR July 2022
All Project Components (Construction, Operation, and Reclamation) The geographic scope for assessing Project consistency with regionally oriented water quality– and hydrology-related management plans for surface and groundwater resources includes the entire Project site and changes resulting from implementation of the Project within the Tar Creek and Sargent Creek watershed areas, which discharge to Carnadero Creek and the lower Pajaro River. For this reason, the following analysis considers the Project in its entirety.

Surface Water
The Basin Plan beneficial uses and water quality objectives are designed to preserve and enhance water quality and protect the beneficial uses of all regional terrestrial surface water bodies (e.g., creeks, rivers, streams, and lakes) and groundwaters within the CCRWQCB’s jurisdictional area.

As discussed above under Impacts 3.10-1, 3.10-2, and 3.10-3, no water quality degradation would occur as a result of the construction, operation, or reclamation of the Project (all components) as compared to baseline conditions. As described under Impact 3.10-1 and Impact 3.10-2, the Project would have a less-than-significant impact on surface water and groundwater quality onsite and off-site. This includes Carnadero Creek and the lower Pajaro River, which are subject to the Basin Plan water quality objectives. Carnadero Creek and the lower Pajaro River currently are classified as impaired for sediment/turbidity, as well as other pollutants not associated with the Project (e.g., legacy pesticides related to agriculture). As discussed under Impact 3.10-1 and Impact 3.10-2, under the Project, stormwater would be retained on-site in retention ponds or conveyed around active industrial areas (i.e., the processing plant site and active mining areas) in a manner consistent with NPDES discharge requirements as well as receiving water Basin Plan water quality objectives, ensuring that receiving waters are not degraded and that beneficial uses defined in the Basin Plan are not impaired.

The Project would comply with the requirements of the Construction General Permit and the Industrial NPDES Permit, including implementation of BMPs and other requirements of associated NPDES Permit required SWPPPs, as well as the requirements of the associated MRP, all of which are designed to ensure stormwater discharges associated with construction, operation maintenance, and reclamation activities at the Project site comply with applicable water quality standards in the Basin Plan. Impacts relating to conflicting with or obstructing implementing of a water quality control plan would be less than significant.

Groundwater
As described in Section 3.10.3.2, Surface Water Resources, the Project site is located partially within the Llagas groundwater subbasin (processing plant area). Valley Water is the designated GSA for portions of the Santa Clara and Llagas groundwater subbasins within Santa Clara County, and as such has prepared a GWMP for the Santa Clara and Llagas (Valley Water 2021a).

This document is an alternative to a GSP required by SGMA and describes Valley Water’s groundwater sustainability goals, and the strategies, programs, and activities that support those goals. As discussed in Section 3.10.2.2, the Project site is close to the basin boundary of the Llagas and San Benito subbasins and thus groundwater management actions in the San Benito Subbasin may affect groundwater use by the Project. PV Water is the designated GSA for the local groundwater basin and must adopt a GSP. PV Water submitted the Basin Management Plan

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-49 ESA / D201901577.01
Draft EIR July 2022
as an alternative to a GSP in December 2016, which the DWR approved as an alternative plan functionally equivalent to a GSP.

The Project would not conflict with or obstruct implementation of Valley Water’s GWMP or the San Benito GSP, as the groundwater users in the Llagas and San Benito’s subbasins are located upgradient of the Project site and the volume of groundwater that is proposed for extraction would not create excessive drawdown to damage nearby production wells. Approval of the Project groundwater well would require confirmation from Valley Water, as the Groundwater Sustainability Agency, that the well would not be inconsistent with the groundwater management plan, per Executive Order N-7-22. The quantities of groundwater consumed by the Project would not adversely affect groundwater users in the Pajaro Valley area located downstream of the Project site (see Impact 3.10-4 for details). Implementation of the Project would not result in impacts related to ongoing substantial groundwater withdrawals or reduce groundwater recharge, as discussed under Impact 3.10-6, and therefore would not conflict with or obstruct implementation of a sustainable groundwater management plan. Impacts relating to conflict or obstruction of implementing a sustainable groundwater management plan would be less than significant.

Mitigation: None required.

Significance after Mitigation: Less than significant
_________________________

3.10.4.4 Cumulative Analysis
Impact 3.10-10: The Project would contribute to significant cumulative degradation of water quality. (Less than Significant with Mitigation)
The Project would occur in areas that drain to Tar Creek and Sargent Creek directly, which in turn discharge into Carnadero Creek and the lower Pajaro River. Therefore, the geographic scope for assessing potential cumulative hydrology and water quality impacts consists of the Project site and the geographic locations of the infrastructure, capital improvement, and private development projects identified in Table 3.1-1 and described in Section 3.1.6 that are reasonably likely to be constructed and/or operated in a similar timeframe as the Project and could contribute incremental water quality and hydrologic impacts to common receiving waters and drainage areas within the watershed. Cumulative impacts are assessed for the life of the Project (i.e., during construction, operation, and reclamation phases). The analysis of cumulative impacts on hydrology and water quality considers those cumulative projects listed in Table 3.1-1. The analysis focuses on cumulative adverse effects on water resources associated with construction and operation of the following projects listed in Table 3.1-1 due to their size and location in relation to receiving waters:
• U.S. 101 Widening Project;
• Shamrock Seeds Project;
• Gilroy Rodeo Grounds;

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-50 ESA / D201901577.01
Draft EIR July 2022
• Z-Best Compost Facility Modification; and
• Christopher Ranch Farm Worker Housing, County of Santa Clara.

Construction
As discussed in Section 3.10.2.2, each project involving disturbance of 1 acre or more of land would be required to comply with the NPDES Construction General Permit. NPDES general permits are designed to establish the regulatory requirements for a broad range of construction activities under differing site conditions with similar discharge characteristics (SWRCB 2013). A standard set of permit requirements prescribed via the Construction General Permit provides effective protection of water resources and ensures compliance with water quality standards for discharges of storm water from construction sites with common receiving waters.

Compliance with the Construction General Permit would require each project involving disturbance of 1 acre or more of land to prepare and implement a SWPPP. The SWPPPs would describe BMPs to control runoff and prevent erosion, sediment transport, and other pollutants from being mobilized or otherwise transported via stormwater runoff to receiving waters for each such project. The Construction General Permit includes several requirements in addition to the SWPPP, including risk-level assessment for construction sites, an active stormwater monitoring and reporting program during construction (for Risk Level II and III sites), rain event action plans for certain higher risk sites, and numeric effluent limitations for pH and turbidity as well as requirements for qualified professionals that prepare and implement the plan. Site risk is determined using a combination of the proposed project’s sediment risk and the risk to receiving water quality. Receiving water risk is based on whether the project drains to a sediment-sensitive water body18, such as the Pajaro River. The risk assessment and SWPPP must be prepared by a State-qualified SWPPP Developer and implementation of the SWPPP must be overseen by a State-qualified SWPPP Practitioner.

In this way, the Construction General Permit addresses cumulative discharges and/or pollutants arising from construction sites throughout the state. For example, two adjacent construction sites would be required to implement BMPs to reduce and control the release of sediment and/or other pollutants in any runoff leaving their respective sites. The runoff water from both sites would be required to achieve the same action levels, measured as a maximum amount of sediment or pollutant allowed per unit volume of runoff water. Thus, even if the runoff waters were to combine after leaving the sites, the sediments and/or pollutants in the combined runoff would still be at concentrations (amount of sediment or pollutants per volume of runoff water) below action levels and would not combine to be cumulatively significant.

Project construction activities would also be consistent with the Construction General Permit; compliance with which would be required by law. However, as discussed in Impact 3.10-1, the Construction General Permit and associated SWPPP requirements do not specifically anticipate direct impacts to water quality that may result from work within stream channels, such as 18 A sediment-sensitive water body is one that appears on the most recent 303(d) list for water bodies as impaired for sediment; has a USEPA-approved TMDL implementation plan for sediment; or has the beneficial uses of cold freshwater habitat, fish migration, and fish spawning.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-51 ESA / D201901577.01
Draft EIR July 2022
proposed for the Tar Creek Bridge and Sargent Creek road crossing. Therefore, construction of the Tar Creek Bridge and Sargent Creek road crossing could contribute considerably to water quality degradation, which would be a significant direct impact, and contribute to a significant cumulative water quality impact, to which the Project’s contribution would be cumulatively considerable and therefore significant.

Operation and Reclamation
As discussed in Section 3.10.2.2, cumulative projects would be required to comply with Phase II NPDES Permit stormwater requirements, including post-construction requirements, for the Central Coast. Such stormwater requirements are part of a regional program designed to address the potential cumulative effects of projects within the region. Adherence to these requirements ensure hydrology and water quality effects related to the alteration of drainage patterns would not cause a significant cumulative impact.

As discussed in Impacts 3.10-2 and 3.10-7, the Project would require site disturbance in a manner that could alter drainage patterns. Most of the projects identified in Table 3.1-1 also would involve new impervious surfaces or land use changes, which may alter site drainage. Alterations to site drainage could cause increased peak flows in creeks and cause hydromodification-related impacts, exacerbate erosion and sedimentation, and result in greater non-point source pollution in downstream water bodies within the Pajaro River watershed area. Increased areas of impervious surfaces could also increase the risk of flooding and the subsequent release of pollutants and also cause runoff volumes to exceed stormwater conveyance system capacities.

The Project includes a stormwater management system made up of a series of drains, swales, conveyance pipes, sediment ponds to treat stormwater (i.e., capture sediment), and retention ponds to hold captured stormwater for percolation and groundwater recharge, as well as use of proposed outfall structures for stormwater discharges that are designed to convey stormwater runoff associated with the 100-year storm event and that are designed sufficiently to dissipate energy of discharges, avoid scour of the channel bed and bank, and avoid or minimize erosion and sedimentation in receiving watercourses. Because the Project would not substantially increase the rate or amount of peak runoff discharged to Sargent Creek, Tar Creek, Carnadero Creek, or the Pajaro River the Project would not contribute considerably to hydromodification impacts, increased flooding or flood risks, erosion, and/or sedimentation on- or off-site, reductions in groundwater recharge.

As discussed in Section 3.10.3.2, Surface Water Resources, Carnadero Creek and the lower Pajaro River are listed as impaired water bodies for sediment and turbidity. Prior to issuance of Industrial General Permits, the CCRWQCB would conduct a review and authorization process to ensure such permits, if granted, would be protective of designated beneficial uses and water quality and that water quality issues, such as impairments for sediment and/or other pollutants are addressed in NPDES discharge Water Quality Protection Standards or discharge requirements and that TMDL requirements are incorporated as permit conditions in a manner consistent with relevant plans, policies, and guidelines. The regulatory review process associated with the Industrial General Permit, similar to that described for the Construction General Permit, has been developed to address cumulative water quality or hydrologic conditions arising from operational

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-52 ESA / D201901577.01
Draft EIR July 2022
discharges within a watershed, and is intended to maintain cumulative effects of projects subject to this requirement below levels that would be considered significant for associated receiving waters. Based on the above analysis, cumulative water quality impacts during operation and reclamation would not be significant, and the Project’s incremental contribution to this impact would not be cumulatively considerable, and thus less than significant.

Mitigation Measure 3.10-10: Implement Mitigation Measure 3.4-4 from Section 3.4, Biological Resources, during Project construction.

Significance after Mitigation: Less than significant
Implementation of the Project’s proposed stormwater drainage plan (Section 2.4.3), erosion and sediment controls (Section 2.4.4), and Hazardous Materials Business Plan (Section 3.9, Hazardous Materials), in combination with Mitigation Measure 3-4.4, would ensure that the Project contribution to cumulative water quality degradation would not be considerable, and therefore less than significant. by requiring actions to protect water quality during construction.
_________________________
Impact 3.10-11: The Project would not contribute to significant cumulative increases in the consumption of groundwater supply. (Less than Significant) The geographic scope for assessing cumulative groundwater impacts is the region overlying the groundwater basins surrounding the Project site and the urban areas of Hollister and Gilroy. The groundwater subbasins are the Llagas Subbasin and Bolsa Subbasin underlying the southern Santa Clara County, the San Juan Bautista in San Benito County, and the Pajaro Valley Water Management Agency service area in the Pajaro River Valley. The temporal scope is 30 years (the life of the Project). Evaluation of the cumulative impacts to downstream uses pertains to potential changes in surface water and groundwater supply. The issue addresses whether Project pumping in conjunction with other foreseeable changes in consumptive use of groundwater in the San Benito River and Pajaro River watersheds would reduce downstream Pajaro River flow to the point that it would no longer supply adequate recharge to meet beneficial uses, including uses for groundwater supply and for environmental benefits, i.e., steelhead habitat (Appendix I.5).

Groundwater users in the Llagas Subbasin in Santa Clara County and the North San Benito basin in San Benito County would be unaffected from a water balance standpoint because they are upgradient of the Project well and impacted river reach. Water users most likely to be affected would be downstream in the Pajaro Valley near Watsonville. Groundwater pumping in that area averaged 52,000 AFY during 2009–2013 (Appendix I.5) and amounted to approximately 42,268 acre-feet in water year 2019 (PVWMA 2020 in Appendix I.5).

The Llagas Subbasin in Santa Clara County is sustainably managed due to the comprehensive activities described in Valley Water’s 2016 Groundwater Management Plan. Groundwater elevation and storage remained in healthy condition through Water Year (WY) 2020. WY 2020 was a dry year, but adequate surface water supplies were available to support managed recharge using local and imported surface water for groundwater replenishment. Treated water delivered

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-53 ESA / D201901577.01
Draft EIR July 2022
by Valley Water provided in-lieu recharge, and countywide water conservation programs reduced water demands. This comprehensive recharge continues to support a balanced long-term groundwater budget. During WY 2020, outflows exceeded inflows in the Llagas Subbasin, resulting in a net decrease in storage of 2,300 acre-feet. However, groundwater storage in WY 2020 remained well within the “Normal” stage under Valley Water’s Water Shortage Contingency Plan (Valley Water 2021b).

The only reasonably foreseeable development project in the Pajaro River/San Benito River watershed is construction of the Pacheco Reservoir Expansion Project. Less specific projections of future groundwater use are included in Urban Water Management Plans for Gilroy and Hollister and in the Northern San Benito County draft groundwater sustainability plan. Each of these components of future groundwater use was considered.

Pacheco Reservoir Expansion Project (PREP)
The proposed Pacheco Reservoir Expansion Project (PREP) would consist of a 140,000-acre-foot reservoir on Pacheco Creek upstream of the Gilroy-Hollister groundwater basin, about 15 miles northeast of Hollister (Valley Water, 2022). Pacheco Creek flows to San Felipe Lake, located about 8 miles northeast of the Project site. The reservoir would primarily store imported surface water from the Central Valley Project, but it would also capture runoff from the Pacheco Creek watershed upstream of the dam site. Preliminary proposals include generally higher flows and recharge during the dry season than presently occur. The releases would not flow all the way to Pajaro Valley, but by increasing average annual recharge to the Gilroy-Hollister Basin they would tend to increase groundwater discharge from that basin to the Pajaro River, which would tend to increase recharge opportunity in Pajaro Valley. The effect would probably be small and beneficial.

Future Growth in Gilroy and Hollister Areas
The City of Gilroy’s 2020 Urban Water Management Plan (Gilroy) projects an increase in municipal water demand of approximately 3,370 AFY by 2045. The City water supply consists of wells in the Llagas Subbasin of the Gilroy-Hollister Basin. The change in consumptive use of groundwater would be much smaller. About 63 percent of municipal use becomes wastewater that is either recycled for irrigation or percolated back into the groundwater basin (Akel Engineering Group 2016 in Appendix I.5). Furthermore, if urban growth replaces irrigated agricultural land, the urban use offsets the existing agricultural use. Because of the high percentage of return flow, per-acre consumptive use following urbanization can be lower than per-acre consumptive use for agriculture.

Growth projections for northern San Benito County were obtained from the draft groundwater sustainability plan, prepared by the San Benito County Water District (SBCWD) (2021). A future growth scenario was developed that estimated an increase of 9,000 AFY of municipal groundwater use in the Hollister area by 2068. Assuming a linear increase, that would correspond to roughly 4,500 AFY by 2040. As with the City of Gilroy, much of the water use is not consumptive. It becomes wastewater that is either percolated back to the groundwater basin or recycled for irrigation. Municipal use of imported Central Valley Project (CVP) water is also projected to increase—by about 700 AFY—and wastewater generated by that use would further

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-54 ESA / D201901577.01
Draft EIR July 2022
offset the increase in municipal groundwater pumping. Furthermore, if urban growth displaces currently irrigated agricultural land, the change in consumptive use of groundwater would likely be small. Simulations of this growth scenario assuming nearly all urban expansion would be onto non-irrigated lands indicated that the increase in pumping would be partially offset by increased percolation from streams and rivers. This would tend to decrease downstream flow in the Pajaro River, but the impact of that decrease on groundwater recharge in the Pajaro Valley area depends on whether the river is flowing to the ocean at that time.

Overall agricultural water use in the Llagas and northern San Benito County areas is not projected to change appreciably. Urbanization might displace some irrigated agriculture, as discussed above. Vineyards have been expanding in the Paicines and Tres Pinos Creek Valley areas of the San Benito River watershed, but the expansion is not expected to be large due to market conditions, and groundwater modeling shows that increased groundwater pumping for irrigation in those areas tends to be offset by increased river and creek percolation in winter, when downstream flows in the Pajaro River already exceed the recharge capacity of the Pajaro Valley area downstream (SBCWD 2020).

In summary, PREP and urban growth could increase consumptive use of groundwater upstream of the Pajaro Valley by anywhere from zero to several thousand acre-feet per year, depending largely on whether urban growth displaces currently irrigated cropland. The impact on groundwater recharge in the Pajaro Valley area would be smaller than the increase in consumptive use because some of the decrease in Pajaro River flow would be at times when percolation in the Pajaro Valley area is at its maximum capacity and the river is flowing to the ocean. In the context of this wide range of uncertainty and in the context of the Pajaro Valley groundwater budget, cumulative groundwater supply impacts would not be significant, and the 83 AFY of consumptive use during the mining phase of the Project would be small and therefore not cumulatively considerable.

Therefore, the incremental Project impact is considered less than significant.

Mitigation: None required.

Significance after Mitigation: Less than significant
_________________________

3.10.5 References
California Department of Water Resources (DWR). 2021 Water Basics. Glossary. Accessed online on November 9, 2021 at https://water.ca.gov/Water-Basics/Glossary.

Central Coast Regional Water Quality Control Board (CCRWQCB). 2019. Water Quality Control Plan for the Central Coastal Basins. Accessed online on March 26, 2021 at: https:// www.waterboards.ca.gov/centralcoast/publications_forms/publications/basin_plan/docs/ 2019_basin_plan_r3_complete_webaccess.pdf.

City of Gilroy. 2021. 2020 Urban Water Management Plan. October 2021. Accessed on February 28, 2022: http://www.ci.gilroy.ca.us/DocumentCenter/View/12538/FINAL-2020- Urban-Water-Management-Plan?bidId=.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-55 ESA / D201901577.01
Draft EIR July 2022
CCRWQCB. 2021. Pajaro River Sediment TMDL. Accessed online March 17 at: https:// www.waterboards.ca.gov/centralcoast/water_issues/programs/tmdl/docs/pajaro/sediment/.

County of Santa Clara. 2007. Santa Clara County Drainage Manual.

County of Santa Clara. 2021. Stormwater Management. Santa Clara County Department of Planning and Development. Accessed online on July 30, 2021 at: https://www.sccgov.org/ sites/dpd/Programs/Stormwater/Pages/Stormwater.aspx.

Federal Emergency Management Agency (FEMA). 2009. Flood Insurance Rate Map 06069C0045D and 0609C0040D. Revised April 16, 2009.

Golder Associates. 2017a. Geotechnical Peer Review, Sargent Ranch Quarry, Santa Clara County. January 19, 2017.

Golder Associates. 2017b. Supplemental Geotechnical Peer Review, Sargent Ranch Quarry, Santa Clara County. October 13, 2017.

San Benito County Water District (SBCWD). 2020. North San Benito Basin Groundwater Model Update and Enhancement 2020. Prepared by Todd Groundwater. March.

San Benito County Water District (SBCWD). 2021. North San Benito County Groundwater Sustainability Plan Draft. Prepared by Todd Groundwater. June 30.

Santa Clara Valley Water District (Valley Water). 2006. Guidelines and Standards for Land Use Near Streams: A Manual of Tools, Standards, and Procedures to Protect Streams and Streamside Resource in Santa Clara County, July 2006.

Santa Clara Valley Water District (Valley Water). 2016. Leroy Anderson Dam Flood Inundation Map Santa Clara County. April.

Santa Clara Valley Water District (Valley Water). 2017. Annual Groundwater Report for Calendar Year 2017. Accessed online on March 18, 2020 https://www.valleywater.org/ sites/default/files/2018-08/2017%20Annual%20GW%20Report_Web.pdf.

Santa Clara Valley Water District (Valley Water). 2020a. One Water Plan, A Roadmap to Manage Our Water Resources: Uvas/Llagas Watersheds. Accessed online on March 19, 2021 at: https://onewaterplan.wordpress.com/watersheds/uvasllagas-watershed/ Santa Clara Valley Water District (Valley Water). 2022. Pacheco Reservoir Expansion Project, https://www.valleywater.org/project-updates/a1-pacheco-reservoir-expansion-project, accessed February 23, 2022.

Santa Clara Valley Water District (Valley Water). 2020b. South Santa Clara County Stormwater Resource Plan. Prepared by: Watershed Stewardship and Planning Division, Environmental Planning Unit.

Santa Clara Valley Water District (Valley Water). 2021a. 2021 Groundwater Management Plan for the Santa Clara and Llagas Subbasin. Final. November.

Santa Clara Valley Water District (Valley Water). 2021b. 2020 Urban Water Management Plan June.

3. Environmental Setting, Impacts, and Mitigation Measures

3.10 Hydrology and Water Quality
Sargent Quarry 3.10-56 ESA / D201901577.01
Draft EIR July 2022
Sierra Geotechnical Services, Inc. (SGS). 2016. Revised Geotechnical Slope Stability Report.

Sargent Ranch Quarry Site, Sargent, Santa Clara County, California. September 12, 2016.

Sierra Geotechnical Services, Inc. (SGS). 2017. Response to Review Comments. Sargent Ranch Quarry Site, Sargent, Santa Clara County, California. August 28, 2017.

State Water Resource Control Board (SWRCB). 2013. Construction General Permit Fact.

Accessed online on July 30, 2021 at: https://www.waterboards.ca.gov/water_issues/ programs/stormwater/docs/constpermits/wqo_2009_0009_factsheet.pdf.

Sutro Science. 2020. Technical peer review of the Flood and Drainage Analysis for Sargent Quarry (August 2020). Sargent Quarry EIR, Santa Clara County, California.

Triad/Holmes Associates (THA). 2018. Preliminary Drainage Study for Old Monterey Road Improvements. August 2018.

U.S. Environmental Protection Agency (USEPA). 2016. Waterbody Quality Assessment Report. 2016 Waterbody Report for Carnadero Creek (Uvas Creek below Bloomfield Road).

U. S. Environmental Protection Agency (USEPA). 2021. How’s My Waterway? Location:

Carnadero Creek and Lower Pajaro River. Accessed online March 26, 2021 at:
https://mywaterway.epa.gov/.s
Wilson, W., and J. Moore. 1998. Glossary of Hydrology. American Geological Institute.

3. Environmental Setting, Impacts, and Mitigation Measures

3.11 Mineral Resources
Sargent Quarry 3.11-1 ESA / D201901577.01
Draft EIR July 2022

3.11 Mineral Resources

3.11.1 Introduction
This section discusses the occurrence and availability of mineral resources at the Project site and evaluates whether the Project would result in a significant impact associated with mineral reserves. The analysis is based in part on publicly available reports and maps published by the California Geological Survey, County of Santa Clara (County).

3.11.2 Regulatory Setting

3.11.2.1 Federal
No federal laws or regulations are applicable to the Project that would reduce an environmental effect on the availability of mineral resources.

3.11.2.2 State
Surface Mining and Reclamation Act
The Surface Mining and Reclamation Act (SMARA) was signed into law in 1975 with the intent to: 1) assure reclamation of mined lands, 2) encourage production and conservation of minerals, and 3) create and maintain surface mining and reclamation policy (regulations). SMARA mandated that the State Geologist initiate mineral land classifications to help identify and protect mineral resources in areas within the state subject to urban expansion or other irreversible land uses, which could preclude mineral extraction. SMARA also allows the California State Mining and Geology Board (SMGB), after receiving classification information from the State Geologist, to designate lands containing mineral deposits of regional or statewide significance. Construction aggregate was selected by the SMGB to be the initial commodity targeted for classification because of its importance to society, its unique economic characteristics, and the imminent threat that continuing urbanization poses to that resource. The State Geologist delineates Mineral Resource Zones (MRZ) depending on the information known about a potential resource and whether that resource is available (discussed in further detail below). The Project site is not within an identified MRZ but an application for its designation as a deposit, containing Portland cement concrete (PCC)-grade aggregate, has been submitted to the California Geological Survey (Freeman Associates 2022).

3.11.2.3 Local
Surface Mining and Reclamation Ordinance
The County’s Surface Mining and Reclamation Ordinance (County Code, Section 4.10.370) was adopted to comply with and implement the provisions of SMARA by adopting procedures for reviewing, approving, and/or permitting surface mining operations, reclamation plans, and financial assurances in the unincorporated areas of the county. The purpose of Section 4.10.370 is to ensure the continued availability of important mineral resources, while regulating surface mining operations as required by SMARA (County of Santa Clara 2020). The ordinance sets forth the general

3. Environmental Setting, Impacts, and Mitigation Measures

3.11 Mineral Resources
Sargent Quarry 3.11-2 ESA / D201901577.01
Draft EIR July 2022
procedural, operational, and reclamation requirements that must be complied with, where applicable, by surface mining and processing operations in the county. The Ordinance contains requirements for the content of a reclamation plan, the review procedure, and mining standards.

Santa Clara County General Plan
One of the primary goals contained within the County’s General Plan is to manage and protect natural environmental resources, including mineral resource commodities. The General Plan discourages urban encroachment and urban development within areas designated as containing high-priority mineral resources, and directs existing or planned mineral resources extraction operations to conduct activities in an environmentally responsible manner, including the reclamation and rehabilitation of depleted mineral extraction sites. Specific policies contained in the Resource Conservation Element of the General Plan are listed below (County of Santa Clara 1994):

Policy R-RC 67: Local supplies of mineral resources should be recognized for their importance to the local, regional, and state economy. Countywide strategies for preserving and managing mineral resources include:
a) Ensuring continued availability of mineral resources to meet long term demand b) Mitigating environmental impacts of extraction and transportation c) Reclaiming sites for appropriate subsequent land uses Policy R-RC 68: Current and future demand for mineral resources in the County, particularly construction aggregates, should be ensured by the following means:
a) Inventorying existing sites, identifying and properly designating potential new sites for protection measures
b) Preserving deposits and access routes
c) Increased use of recycled material
d) Proper development of new quarry sites
Policy R-RC 69: Existing sites and access routes for regionally significant resources should be protected from incompatible land uses and development that would preclude or unnecessarily limit resource availability.

Policy R-RC 70: When making land use decisions involving mineral resource areas of state or regional significance, decisions about alternative land uses should be carefully balanced against the importance of the mineral deposits to their market region as a whole.

3.11.3 Environmental Setting

3.11.3.1 Aggregate Resources
Regional Demand
Sand, gravel, and crushed stone are construction materials collectively referred to as aggregate.

These materials provide the bulk and strength to Portland Pozzolana Cement (PCC), roadway asphalt, plaster, and stucco. Aggregate is also used as road base, subbase, railroad ballast, and fill.

3. Environmental Setting, Impacts, and Mitigation Measures

3.11 Mineral Resources
Sargent Quarry 3.11-3 ESA / D201901577.01
Draft EIR July 2022
California consumes large quantities of aggregate and future demand is expected to increase throughout California in the coming years (CGS 2018). Aggregate materials are needed to maintain existing infrastructure and for new construction, so these materials can be an important resource to the regional economy. Further, aggregate is generally low in cost but high in bulk weight so it is essential that these materials can be obtained from nearby sources to reduce costs and environmental impacts associated with transportation (CGS 2018).

The two regions of regional significance for aggregate resources pertinent to the Project site are the Monterey Bay Production-Consumption (P-C) Region and the South San Francisco P-C Region (CGS 1987a, 1987b). The Project site is within the Monterey Bay P-C region. In 2018, the 50-year demand for aggregate resources in the Monterey Bay P-C Region was 333 million tons, and the region had 297 million tons of permitted reserves (89 percent of 50-year demand).

The California Geological Survey projects that these reserves could last for the next 41 to 50 years.

In the South San Francisco P-C Region, which is north adjacent to the Monterey P-C Region, the 50-year demand is 1,320 million tons with 506 million tons of permitted reserves (38 percent of 50-year demand). These reserves are expected to last for next 21 to 30 years (CGS 2018).

Project Site Aggregate Resources
The potential aggregate resource at the Project site is sand and gravel, which is suitable material for producing PCC.1 This resource is derived from the geologic deposits underlying the Project site and surrounding areas. The geologic deposits, as described in detail in Section 3.7, Geology and Soils, consist of Pliocene-aged [(11 to 3 million years ago (mya)] sandstone and conglomerate2 of both marine and non-marine origin. These sand and gravel deposits, considered part of the Etchegoin Formation, underlie the surface alluvial materials and topsoil and are interbedded3 with sandy and silty clays to a depth of about 270 feet (SGS 2016).

Aggregate Resource Zoning and Local Availability
The California Geological Survey has designated mineral resources in the San Francisco-Monterey Bay P-C regions into MRZs based on guidelines adopted by the SMGB. Classification assists the SMGB in designating lands that contain valuable mineral resources, as mandated by SMARA.

The objective of the classification and designation process is to ensure that mineral deposits of statewide or regional significance are considered for availability when needed (CGS 1999). MRZ classifications are defined as:

MRZ-1: Areas where adequate information indicates that no significant mineral deposits are present, or where it is judged that little likelihood exists for their presence.

MRZ-2: Areas where adequate information indicates that significant deposits are present, or where it is judged that a high likelihood for their presence exists. 1 Portland cement is the basic ingredient of concrete. PCC is formed when Portland cement creates a paste with water that binds with the aggregate (i.e., sand, gravel, and crushed rock) to harden. Cement is manufactured through a tightly controlled chemical combination of calcium, silicon, aluminum, iron, and other ingredients. 2 A conglomerate is a sedimentary rock made up of many smaller rocks within a cemented matrix. 3 Interbedded refers to sedimentary beds lying between or alternating with others of different character (Jackson 1997).

3. Environmental Setting, Impacts, and Mitigation Measures

3.11 Mineral Resources
Sargent Quarry 3.11-4 ESA / D201901577.01
Draft EIR July 2022
MRZ-3: Areas that contain mineral deposits, but their significance cannot be evaluated from available data.

MRZ-4: Areas where available information is inadequate for assignment of MRZ classification.

Mineral resources including hard rock and geologic deposits similar to those underlying Sargent Ranch, have been classified as MRZ-2 near the Project site. The active mining operation closest to Sargent Ranch is the Graniterock-Aromas facility located 4 miles southwest. This facility extracts Cretaceous-age (136 to 65 mya) igneous4 rocks (referred to Hornblende-Gabbro) for PCC and processes several other marketable products, including sand and gravel. The Hornblende Gabbro MRZ-2 sector extends southeast of the Graniterock facility along the San Andreas Fault Zone, but is not currently owned or controlled by aggregate producers. An elongated sand and gravel MRZ-2 sector begins 2 miles south-southeast of the Project site where U.S. 101 crosses the San Benito River and extends approximately 4 miles upstream (USGS 1955, Revised 1993; CGS 1987). This MRZ-2 sector is not currently owned or controlled by aggregate producers (CGS 1987).

The sand and gravel deposits underlying Sargent Quarry are not yet identified as an MRZ-2 deposit containing suitable PCC-grade aggregate. An application for SMGB designation has been filed and is pending agency review and the update of the resource sector to the Monterey Bay P-C Region within the Chittenden Quadrangle5 (Freeman Associates 2022).

3.11.4 Impact Evaluation

3.11.4.1 Approach to the Analysis
The impact analysis for mineral resources involved reviewing geologic descriptions and the mining plan to assess the degree to which the aggregate deposits represent a sufficient volume and are accessible. The analysis also assesses the existing zoning and whether mineral extraction is permitted in this area. The Project site is zoned AR-d1 and AR-d1-sr. The AR zone refers to Agricultural Ranchlands, where mineral extraction is a permitted use, with approval of a Use Permit (Zoning Code, Section 2.20.010(B).

3.11.4.2 Significance Criteria
Pursuant to CEQA Guidelines Appendix G, a significant impact would result if the Project would either:
a) Result in the loss of availability of a known mineral resource that would be of value to the region and residents of the state.
b) Result in the loss of availability of a locally important mineral resource recovery site delineated on a local general plan, specific plan, or other land use plan. 4 Igneous Rocks refer to those that were solidified from molten or partly molten material (i.e., magma). 5 The California Geological Survey divides the Monterey Bay Production Consumption Region by the designated USGS

7.5-Minute Quadrangle Maps. The Project site is within the Chittenden Quadrangle (USGS 1955, revised 1993).

3. Environmental Setting, Impacts, and Mitigation Measures

3.11 Mineral Resources
Sargent Quarry 3.11-5 ESA / D201901577.01
Draft EIR July 2022

3.11.4.3 Project Impacts
Impact 3.11-1: The Project could result in the loss of a valuable mineral resource or loss of a locally important mineral resource recovery site (Less than Significant).

This impact discussion corresponds to Significance Criteria (a) and (b).

Construction, Operation, and Reclamation
All Project Components
The mineral resources impact discussion applies to the Project site as a whole and its proposed future operation as an aggregate quarry and processing facility; the individual components of the Project (mining pits, processing plant, conveyor belt, rail spur, access road, roadway improvement, and reclamation) are not discussed or analyzed individually, because they all contribute to the extraction of aggregate resources from the Project site.

The Project site is currently open range land zoned by the County as AR-d1 and AR-d1-sr, referring to Agricultural Ranchlands where mineral extraction is a permitted. There is no existing or planned development on the Project site that would hinder future mineral extraction. The limits of the mineral resource have been identified and characterized and the Reclamation Plan has demonstrated that pit mining and eventual reclamation in the four stages would be feasible. The Project would not result in a loss of a valuable or locally important mineral resource; rather, it would enable the extraction of an aggregate resource that would benefit the region and residents of the state.

The Project would contribute to reducing a regional deficit of aggregate material over the next 30 years. The Monterey Bay P-C Region has 89 percent of its demand available in permitted aggregate reserves, which is projected to last at least 41 years, but the South San Francisco Bay Region has only 38 percent of its demand with reserves expected to last 21 to 30 years. The proximity of the site to the South San Francisco Bay P-C Region and access to railroad transportation would allow the Project to provide aggregate to other areas of the state besides those destinations within the Monterey P-C Region.

The Project would develop an accessible, long-term (30-year) source of aggregate material for infrastructure maintenance and new construction throughout the region and the state, and would support General Plan direction, particularly Policy R-RC 68 (proper development of new quarry sites). This would be a beneficial effect of the Project and therefore, in terms of adverse impacts, the impact would be less than significant.

Mitigation: None required.

Significance: Less than significant
_________________________

3. Environmental Setting, Impacts, and Mitigation Measures

3.11 Mineral Resources
Sargent Quarry 3.11-6 ESA / D201901577.01
Draft EIR July 2022

3.11.4.4 Cumulative Analysis
Impact 3.11-2: The Project could contribute to cumulative loss of availability of a known mineral resource or loss of a locally important mineral resource recovery site. (Less than Significant)
The geographic scope for the cumulative analysis of mineral resources is the Monterey Bay and South San Francisco Bay P-C regions. The temporal scope is 30 years, which is the duration of the requested Use Permit. All of the projects listed in Table 3.1-1, Cumulative Projects List, are in areas designated MRZ-1 as areas where adequate information indicates that no significant mineral deposits are present, or where it is judged that little likelihood exists for their presence (CGS 1987a). Therefore, none of these projects would result in the loss of important mineral resources.

Therefore, the cumulative loss of mineral resources would be a less-than-significant cumulative impact, and Project’s incremental contribution would not be cumulatively considerable, and therefore would be less than significant.

The Project would not result in a loss of availability of aggregate resources because it would develop a quarry that would extract, process, and transport aggregate materials, thereby helping to relieve resource demand deficits. The aggregate products supplied by the Project would be additive to those materials already being provided by existing mines and to those that are reasonably foreseeable in the future. The Project would also help replenish regional aggregate resources that are lost as current mines cease operations due to exhausted reserves. Therefore, the Project would have a cumulative beneficial effect to regional aggregate resource availability.

Mitigation: None required.

Significance: Less than significant
_________________________

3.11.5 References
California Geological Survey (CGS) (formerly California Division of Mines and Geology). 1987a. Mineral Land Classification: Aggregate Materials in the South San FranciscoMonterey Bay Area; Part IV: Classification of Aggregate Resource Area in the Monterey Bay Production-Consumption Region, Special Report 146.

California Geological Survey (CGS) (formerly California Division of Mines and Geology). 1987b. Mineral Land Classification: Aggregate Materials in the South San FranciscoMonterey Bay Area; Part II: Classification of Aggregate Resource Area in the Monterey Bay Francisco Bay Production-Consumption Region, Special Report 146, Aggregate Resource Sectors Maps 4.35, 4.38, 4.40. Bases: Chittenden, San Juan Bautista, and Watsonville West (respectively) USGS 7.5-Minute USGS Quadrangle California Geological Survey (CGS). 1999. Update of Mineral Land Classification Map, Aggregate Materials in the Monterey Bay Production-Consumption Region, By Susan Kohler-Antablin, DMG Open File Report 99-01.

3. Environmental Setting, Impacts, and Mitigation Measures

3.11 Mineral Resources
Sargent Quarry 3.11-7 ESA / D201901577.01
Draft EIR July 2022
California Geological Survey (CGS). 2018. Aggregate Sustainability in California. By John Clinkenbeard and Fred Guis. CGS Map Sheet 52
County of Santa Clara. 1994. Santa Clara County General Plan 1995–2010, Book B, adopted December 20, 1994.

County of Santa Clara. 2000. Surface Mining and Land Reclamation Standards, rev. Aug. 29, 2000.

County of Santa Clara. 2020. Santa Clara County Zoning Ordinance, Section 4.10.370 - Surface Mining. March.

Freeman Associates. 2022. Sargent Quarry Mining and Reclamation Plan, January2022. (Appendix B of this EIR.)
University of California Museum of Paleontology (UCMP), 2009. UCMP Glossary, Volume 2:

Geology.

Sierra Geotechnical Services, Inc. (SGS). 2016. Revised Geotechnical Slope Stability Report.

Sargent Ranch Quarry Site, Sargent, Santa Clara County, California. September 12, 2016.

U.S. Geological Survey (USGS). 1955, Revised 1993. Chittenden, California. U.S. Geological Survey 7.5 Topographic Map. Scale 1:24,000.

3. Environmental Setting, Impacts, and Mitigation Measures

3.11 Mineral Resources
Sargent Quarry 3.11-8 ESA / D201901577.01
Draft EIR July 2022
This page intentionally left blank

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-1 ESA / D201901577.01
Draft EIR July 2022

3.12 Noise

3.12.1 Introduction
This section discusses the effects of the Project on the existing noise and vibration environment in the vicinity of the Project site. The analysis focuses on impacts on humans and structures; potential effects on wildlife are addressed in Section 3.4, Biological Resources. The following discussion is based in part on a Noise and Vibration Assessment and supplemental memo prepared by Illingworth & Rodkin, Inc., in February 2017 and February 2019, which are included as Appendix J to this EIR.1

3.12.1.1 Technical Background Information - Noise
Sound is mechanical energy transmitted by pressure waves through a medium such as air. Noise is defined as unwanted sound. Sound is characterized by various parameters that include the rate of oscillation of sound waves (frequency), the speed of propagation, and the pressure level or energy content (amplitude). In particular, the sound pressure level has become the most common descriptor used to characterize the “loudness” of an ambient sound level. Sound pressure level is measured in decibels (dB), with zero dB corresponding roughly to the threshold of human hearing, and 120 to 140 dB corresponding to the threshold of pain.

Typically, sound does not consist of a single frequency, but rather a broad band of frequencies varying in levels of magnitude and measured in hertz (Hz). The typical human ear is not equally sensitive to all frequencies of the audible sound spectrum. Consequently, when assessing potential noise impacts to humans, sound is measured using an electronic filter that deemphasizes the frequencies below 1,000 Hz and above 5,000 Hz in a manner corresponding to the human ear’s decreased sensitivity to low and extremely high frequencies. This method of frequency weighting is referred to as A-weighting and is expressed in units of decibels (dBA).2 Noise Exposure and Community Noise
Noise exposure for any individual is a measure of the noise experienced by the individual over a period of time. A noise level is a measure of noise at a given instant in time. The noise levels presented in Figure 3.12-1 represent noise measured at a given instant in time; however, noise levels rarely persist consistently over a long period of time. Rather, community noise varies over time because of the contributing sound sources of the community noise environment. Community noise is primarily the product of many distant noise sources, which constitute a relatively stable background noise in which the individual contributors cannot be identified. The background noise level changes throughout a typical day, but does so gradually, corresponding to the addition and subtraction of distant noise sources such as traffic and wind. What makes community noise 1 Note that when the Noise and Vibration Assessment was prepared, the assumed phasing differed from the phasing that is currently proposed. The phasing information from the Assessment has been organized to correctly correspond with the phases described in Chapter 2, Project Description. 2 All noise levels reported herein reflect A-weighted decibels unless otherwise stated. 110
100
90 80
70 60
50 40
30 20
10 0

LOCAL COMMITTEE ACTIVITY WITH

INFLUENTIAL OR LEGAL ACTION

LETTERS OF PROTEST
Rock Band
Inside Subway Train (New York)
Food Blender at 3 Ft.

Garbage Disposal at 3 Ft.

Shouting at 3 Ft.

Vacuum Cleaner at 10 Ft.

Large Business Office
Concert Hall (Background)
Broadcast and Recording Studio
Threshold of Hearing
Jet Flyover at 1000 Ft.

COMMON INDOOR

NOISE LEVELS

COMMON OUTDOOR

NOISE LEVELS
NOISE
LEVEL
(dBA, Leq)

PUBLIC REACTION
Gas Lawn Mower at 3 Ft.

Diesel Truck at 50 Ft.

Noisy Urban Daytime
Gas Lawn Mower at 100 Ft.

Commercial Area
Heavy Traffic at 300 Ft.

Quiet Urban Nighttime
Quiet Suburban Nighttime
Quiet Rural Nighttime

COMPLAINTS LIKELY

COMPLAINTS POSSIBLE

COMPLAINTS RARE

ACCEPTANCE
4 Times As Loud
Twice As Loud
1/2 As Loud
1/4 As Loud

REFERENCE
Small Theater, Large
Conference Room (Background)
Library
Dishwasher Next Room Quiet Urban Daytime
%PSBEP0BLT5FOUBUJWF4VCEJWJTJPO.BQ1SPKFDU
Figure 4.-1
Typical Noise Levels
SOURCE: Caltrans Transportation Laboratory Noise Manual, 1982; and modication by ESA D170192.00 - The Towers on Capitol Mall\05 Graphics-GIS-Modeling\Illustrator Figure 3.12-1
Typical Noise Levels
SOURCE: Caltrans Transportation Laboratory Noise Manual, 1982; and modication by ESA SCC Sargent Quarry SFO/19xxxx/D191577.00 - SCC Sargent Quarry/05 Graphics-GIS-Modeling/Illustrator

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-3 ESA / D201901577.01
Draft EIR July 2022
constantly variable throughout a day, besides the slowly changing background noise, is the addition of short-duration, single-event noise sources (e.g., aircraft flyovers, motor vehicles, sirens) that are readily identifiable to the individual.

These successive additions of sound to the community noise environment vary the community noise level from instant to instant, requiring the measurement of noise exposure over a period of time to accurately characterize a community noise environment. This time-varying characteristic of environmental noise is described using statistical noise descriptors. The most frequently used noise descriptors are summarized below.

Leq: The equivalent sound level is used to describe noise over a specified period of time, typically 1 hour, in terms of a single numerical value. The Leq is the constant sound level, which would contain the same acoustic energy as the varying sound level, during the same time period (i.e., the average noise exposure level for the given time period).

Lmax: The instantaneous maximum noise level for a specified period of time.

L50: The noise level that is equaled or exceeded 50 percent of the specified time. This is the median noise level during the specified time.

L90: The noise level that is equaled or exceeded 90 percent of the specified time. The L90 is often considered the background noise level averaged over the specified time.

Ldn: The Day/Night Average Sound Level is the 24-hour day and night A-weighed noise exposure level, which accounts for the greater sensitivity of most people to nighttime noise by weighting noise levels at night. Noise between 10:00 p.m. and 7:00 a.m. is weighted (penalized) by adding 10 dBA to take into account the greater annoyance from nighttime noise. (Also referred to as “DNL.”)
CNEL: The community noise equivalent level. This is the average A-weighted noise level during a 24-hour day that is obtained after 5 dBA are added to noise levels measured between 7 and 10 p.m. and 10 dBA are added to noise levels between 10 p.m. and 7 a.m. to account for noise sensitivity in the evening and nighttime, respectively. The CNEL metric is reported as a number and is generally understood to be in terms of A-weighted decibels.

Effects of Noise on People
The effects of noise on people can be placed into three categories:
• Subjective effects of annoyance, nuisance, dissatisfaction • Interference with activities such as speech, sleep, learning • Physiological effects such as hearing loss or sudden startling The World Health Organization (WHO) defines environmental noise as noise from all sources with the exception of workplace noise. Environmental noise typically produces effects in the first two categories (see Figure 3.12-1). Workers in or near industrial plants would be the most likely to experience noise in the last category.

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-4 ESA / D201901577.01
Draft EIR July 2022
An important way of predicting a human reaction to a new noise environment is the way it compares to the existing environment to which one has adapted: the so called “ambient noise” level. With regard to increases in A-weighted noise level, the following relationships are known to exist:
• Under controlled conditions in an acoustics laboratory, the trained healthy human ear is able to discern changes in sound levels of 1 dBA.
• It is widely accepted that the average healthy ear can barely perceive changes in the noise level of 3 dBA.
• A change in level of 5 dBA is a readily perceptible increase in noise level. • A 10 dBA change is recognized as twice as loud as the original source (Caltrans 2013).

3.12.1.2 Technical Background Information - Vibration
Vibration is an oscillatory motion through a solid medium in which the motion’s amplitude can be described in terms of displacement, velocity, or acceleration. Several different methods are used to quantify vibration. The peak particle velocity (PPV) is defined as the maximum instantaneous peak of the vibration signal. The PPV is most frequently used to describe physical vibration impacts on buildings. Typical groundborne vibration generated by human activities attenuates rapidly with distance from the source of the vibration. Sensitive receptors to vibration include people (especially residents, the elderly, and sick people), structures (especially older masonry structures), and vibration-sensitive equipment.

Another useful vibration descriptor is known as vibration decibels or VdBs. VdBs are generally used when evaluating human response to vibration, as opposed to structural damage (for which PPV is the more commonly used descriptor). Vibration decibels are established relative to a reference quantity, typically 1 x 10-6 inches per second (FTA 2018).

There are no major sources of vibration in the Project site vicinity. Most motor vehicles and trucks have independent suspension systems that substantially reduce if not eliminate vibration generation, barring discontinuities in the roadway.

3.12.2 Regulatory Setting
Federal, state, and local agencies regulate different aspects of environmental noise. Federal and state agencies generally set noise standards for mobile sources such as aircraft and motor vehicles, while regulation of stationary sources is left to local agencies. Local regulation of noise involves implementation of general plan policies and noise ordinance standards. Local general plans identify general principles intended to guide and influence development plans; local noise ordinances establish standards and procedures for addressing specific noise sources and activities.

The Project site and its environs are subject to the noise and vibration policies and standards of the County of Santa Clara General Plan and Ordinance Code.

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-5 ESA / D201901577.01
Draft EIR July 2022

3.12.2.1 Federal
U.S. Department of Labor, Mine Safety and Health Administration (MSHA) The mission of the Mine Safety and Health Administration (MSHA) is to administer the provisions of the Federal Mine Safety and Health Act of 1977 (Mine Act) and to enforce compliance with mandatory safety and health standards as a means to eliminate fatal accidents; to reduce the frequency and severity of nonfatal accidents; to minimize health hazards; and to promote improved safety and health conditions in the Nation's mines. MSHA carries out the mandates of the Mine Act at all mining and mineral processing operations in the United States, regardless of size, number of employees, commodity mined, or method of extraction.

MSHA’s noise standards (1999) require mine operators to monitor workplace noise exposure and provide for miners and their representatives to observe the monitoring. The standards establish several levels requiring mine operators to take action:
• Miners exposed to an average sound level of 85 decibels (85 dBA) or more over an 8-hour period must be enrolled in a hearing protection program, which will include special training, hearing tests, and hearing protection.
• If workplace noise levels reach 90 dBA or more over an 8-hour period, mine operators must use feasible engineering and administrative controls to reduce noise levels. Hearing protectors are required to be provided and worn if the permissible exposure level cannot be achieved using feasible engineering and administrative controls. • At workplace noise levels of 105 dBA or more over an 8-hour period, mine operators must ensure the use of both ear plug and earmuff type hearing protectors. • At no time during the work shift may noise levels exceed 115 dBA.

3.12.2.2 State
California Building Code
State regulations include requirements for the construction of new hotels, motels, apartment houses, and dwellings other than detached single-family dwellings that are intended to limit the extent of noise transmitted into habitable spaces. These requirements are collectively known as the California Noise Insulation Standards and are found in Title 24 of the California Code of Regulations. Regulations for single-family homes are not established at the State level.3 California Aeronautics Act
California’s State Aeronautics Act, as set forth in relevant part in Public Utilities Code (PUC) Section 21670 et seq., charges airport land use commissions (ALUCs) with the responsibility of protecting “… public health, safety, and welfare by ensuring the orderly expansion of airports and the adoption of land use measures that minimize the public’s exposure to excessive noise and 3 Noise standards for single family homes are usually established in county or city general plan noise elements, and those are mostly for land use compliance for exterior noise levels (ranging from 60 to 65 dBA CNEL) and 45 dBA CNEL for interior noise standard (the same as State regulations for multi-family housing). Because single family homes are just for one family, by definition, there are no concerns with regard to sound transmission between rooms.

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-6 ESA / D201901577.01
Draft EIR July 2022
safety hazards within areas around public airports to the extent that these areas are not already devoted to incompatible uses” (PUC Section 21670(a)(2)). In order to accomplish this goal, ALUCs are required to prepare airport land use compatibility plans (ALUCPs) that are based on a long-range master plan or an airport layout plan that reflects the anticipated growth of the airport during the next 20 years (PUC Section 21675(a)). ALCUPs address the safety and noise standards and impacts and require development of existing and future aircraft noise contour maps. As described in Section 3.12.4.2, the Project is not located within the planning area of any ALUCP.

3.12.2.3 Local
The County of Santa Clara regulates noise through implementation of its Ordinance Code and through implementation of its General Plan Safety and Noise Chapter, and Health Element. The Safety and Noise Chapter establishes interior and exterior noise compatibility standards for various land uses as well as recommended maximum interior noise levels for intermittent use.

These standards are used to assess the appropriateness of siting and design of new land uses within the County.

County of Santa Clara General Plan
The County of Santa Clara General Plan Safety and Noise Chapter and Mineral Resources Chapter contain the following strategies, policies, and implementation actions with regard to noise:

Policy C-HS 24: Environments for all residents of Santa Clara County free from noises that jeopardize their health and well-being should be provided through measures which promote noise and land use compatibility.

Policy C-HS 25: Noise impacts from public and private projects should be mitigated.

Implementation Recommendations:

C-HS(i) 23: Project design review should assess noise impacts on surrounding land uses.

C-HS(i) 24: Where necessary, construct sound walls or other noise mitigations.

C-HS(i) 25: Prohibit construction in areas which exceed applicable interior and exterior standards, unless suitable mitigation measures can be implemented.

C-HS(i) 26: Require project-specific noise studies to assess actual and projected dB noise contours for proposed land uses likely to generate significant noise.

C-HS(i) 27: Take noise compatibility impacts into account in developing local land use plans.

Policy C-HS 26: New development in areas of noise impact (areas subject to sound levels of 55 DNL or greater) should be approved, denied, or conditioned so as to achieve a satisfactory noise level for those who will use or occupy the facility (as defined in “Noise Compatibility Standards for Land Use” and “Maximum Interior Noise Levels for Intermittent Noise” [see Table 3.12-1]).

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-7 ESA / D201901577.01
Draft EIR July 2022
Policy R-RC 77: Noise impacts to residences along haul routes should be reduced to the maximum extent possible. Sound barriers should be erected where necessary to minimize truck noise impacts on private residences located near quarry access points to public roads.

TABLE 3.12-1

RECOMMENDED MAXIMUM INTERIOR NOISE LEVELS FOR INTERMITTENT NOISE Land Use Category Land Use Type
Maximum Interior
Noise Level (dBA)
Residential Single Family Residential 45
Multi-Family Residential 45
Commercial Hotel-Motel 45
Executive Offices, Conference Rooms 55
Staff Offices 60
Restaurant, Market, Retail Stores 60
Sales, Secretarial 65
Sports Arena, Bowling Alley, etc. 75
Industrial Offices (same as above) 55-60
Laboratory 60
Machine Shop, Assembly and others 75
Mineral Extraction 75
Public or Semi-Public Facility Concert Hall and Legitimate Theater 30 Auditorium, Movie Theater, and Church 45
Hospital, Nursing Home and Firehouse (Sleeping Quarters) 45 School Classroom 50
Library 50
Other Public Buildings 55
SOURCE: County of Santa Clara 1994.

County of Santa Clara Noise Ordinance
The County noise ordinance, Title B, Division B11, Chapter VIII of the County of Santa Clara Ordinance Code, was established to control unnecessary, excessive, and annoying noise and vibration, and to maintain quiet in those areas that exhibit low noise levels and to implement programs aimed at reducing noise in those areas where noise levels are above acceptable values.

The ordinance generally prohibits any sound that endangers or injures the safety or health of human beings or animals, annoys or disturbs a person of normal sensitivities, or endangers or injures personal or real properties. The ordinance gives the County Director of Environmental Health discretion to grant variances from the County’s noise standards if the director determines that the activity will not create a nuisance and will not be detrimental to the public health and safety. The director may impose conditions that are reasonable and necessary to protect public health, safety and welfare from adverse noise effects.

Exterior Noise Standards
The County of Santa Clara noise ordinance establishes exterior noise levels not to be exceeded on another property for more than 30 minutes in a given hour (L50). These standards are presented in

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-8 ESA / D201901577.01
Draft EIR July 2022
Table 3.12-2. If the noise measurement occurs on a property adjoining a different land use category, the noise level limit applicable to the lower land use category, plus 5 dB, applies. In the event the alleged offensive noise contains a steady, audible tone such as a whine, screech or hum, or contains music or speech conveying informational content, the standard limits are to be reduced by 5 dB.

TABLE 3.12-2

COUNTY OF SANTA CLARA NOISE ORDINANCE EXTERIOR NOISE LIMITS Receiving Land Use Category Time Period
Maximum Exterior
Noise Level (dBA L50)
One- and Two-Family Residential 10:00 p.m. - 7:00 a.m.
7:00 a.m. - 10:00 p.m.
45 55
Multiple-Family Dwelling 10:00 p.m. - 7:00 a.m. 50
Residential Public Space 7:00 a.m. - 10:00 p.m. 55
Commercial
10:00 p.m. - 7:00 a.m. 60
7:00 a.m. - 10:00 p.m. 65
Light Industrial Any Time 70
Heavy Industrial Any Time 75
SOURCE: County of Santa Clara Code Chapter VIII, Section B11-152.

Per Section B11-152(3), if the measured ambient level exceeds that permissible within any of the first four noise limit categories listed in Table 3.12-2, the allowable noise exposure standard will be increased in five dB increments in each category as appropriate to encompass or reflect the ambient noise level. In the event the ambient noise level exceeds the fifth noise limit category, the maximum allowable noise level under the category will be increased to reflect the maximum ambient noise level.

Interior Noise Standards
The County has interior noise standards; however, they do not apply to the Project. For multifamily residential units, the County noise ordinance establishes interior noise level standards.

Between the hours of 10:00 p.m. and 7:00 a.m. a maximum interior noise levels standard of 35 dBA applies, while between the hours of 7:00 a.m. and 10:00 p.m. a maximum interior noise levels standard of 45 dBA applies.

Construction Noise Standards
The County noise ordinance contains separate standards for addressing noise from construction and demolition. First, the noise ordinance establishes allowable hours of construction.

Specifically, operation of any tools or equipment used in construction, drilling, repair, alteration or demolition work between weekdays and Saturday hours of 7:00 p.m. and 7:00 a.m., or at any time on Sundays or holidays, that creates a noise disturbance across a residential or commercial real property line is prohibited, except for emergency work of public service utilities or by variance.

Secondly, the County noise ordinance requires construction activities to be conducted, where technically and economically feasible, in a manner that noise levels at affected properties not

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-9 ESA / D201901577.01
Draft EIR July 2022
exceed certain levels. The ordinance establishes noise level standards for affected properties for both mobile and stationary equipment. These standards are presented in Table 3.12-3. The County noise ordinance also contains an exemption for the emission of sound in the performance of emergency work.

TABLE 3.12-3

COUNTY OF SANTA CLARA NOISE ORDINANCE STANDARDS FOR CONSTRUCTION EQUIPMENT Single- and Two-Family
Dwelling Residential
Area (dBA)
Multifamily Dwelling
Residential Area (dBA)
Commercial Area
(dBA)
Mobile Equipment
Daily, except Sundays and legal
holidays 7:00 a.m.-7:00 p.m. 75 80 85
Daily, 7:00 p.m. to 7:00 a.m. and
all day Sunday and legal holidays 50 55 60
Stationary Equipment
Daily, except Sundays and legal
holidays 7:00 a.m.-7:00 p.m. 60 65 70
Daily, 7:00 p.m. to 7:00 a.m. and
all day Sunday and legal holidays 50 55 60
SOURCE: County of Santa Clara Code Chapter VIII, Section B11-154(b)(6).

Vibration
The noise ordinance prohibits operating or permitting the operation of any device that creates a vibrating or quivering effect that endangers or injures the safety or health of human beings or animals; annoys or disturbs a person of normal sensitivities or endangers or injures personal or real properties. Quantitative vibration standards are not established in the County Ordinance Code.

County of Santa Clara Surface Mining Regulations
The County’s surface mining supplemental use regulations are established in Section 4.10.370 of the County Zoning Code. Part II of this code section contains the following County regulations with respect to noise and vibration:
a. Noise and ground vibration shall be mitigated to a level of insignificance in the absence of an approved Statement of Overriding Considerations pursuant to CEQA. To achieve this, loading points shall not be located closer than 30 feet to any property line, unless otherwise permitted by the Planning Commission.
b. Noise attenuation measures shall be installed where necessary to reduce noise levels in order to comply with noise standards of the County General Plan and Noise Ordinance. c. Use of explosives (blasting) in operations shall be noted on the permit application and subject to Planning Commission conditioning, and shall comply with the noise and vibration standards of the County Noise Ordinance.

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-10 ESA / D201901577.01
Draft EIR July 2022

3.12.3 Environmental Setting
Transportation sources, such as automobiles, trucks, trains, and aircraft, are the principal sources of noise in the Project environs. Primary noise sources in the immediate vicinity of the Project site include traffic on the network of highways and local streets, including U.S. 101 and State Route 129 (SR 129). There is also an active quarry, the Graniterock Aromas Transportation Division, located approximately 3 miles to the southwest that generates truck traffic onto these two highways.

The area surrounding the Project site is characterized as open space with low-density rural residences, a small subdivision to the south along SR 129, Betabel RV Park to the east, and rural residences to the north and northeast. Suburban homes and a school are located about 3 miles north of the site in the City of Gilroy.

A noise monitoring survey was conducted in November 2016 (Appendix J.1) and is representative of existing ambient noise levels at receptors near the Project site. Three unattended long-term noise measurements and three attended short-term noise measurements were made to document existing noise levels representative of the nearest residential and other noise sensitive receptors. Long-term measurements of hourly average noise levels and other metrics were used to establish the existing noise levels in terms of the Ldn noise metric. Short-term noise measurements characterize typical daytime noise conditions and were also used to validate the traffic noise model used in the impact analysis (Appendix J.4). A summary of the results of the three long-term noise measurements is shown in Table 3.12-4.

TABLE 3.12-4

LONG-TERM NOISE DATA
Location Ldna Leqb Primary Noise Sources (Lmax)
LT-1: West of Betabel RV Park 59 48 to 56 U.S. 101 and existing noise at Betabel RV Park
LT-2: Near residences in the vicinity of
School Road and Payne Road 62 51 to 63 Traffic on SR 129 LT-3: Old Monterey Road, west of U.S. 101 66 54 to 63 Traffic on U.S. 101 NOTES:
a Ldn: the day-night average noise level b Leq: the daytime weekday hourly average noise levels SOURCE: Appendix J.1.

Noise levels at the long-term locations were measured from the afternoon of Wednesday, November 16, 2016, to the afternoon of Friday, November 18, 2016. Short-term measurements were made on Friday, November 18, 2016. Locations of the measurements are shown in Figure 3.12-2. The closest sensitive receptors to proposed mining areas are residences in the Betabel RV Park on Betabel Road (measurement location LT-1 in Figure 3.12-2) and a single-family residence located approximately 1,600 feet east of the Project site. Several single-family residences are located approximately 5,000 feet south of the Phase 3 and Phase 4 mining areas on SR 129. 6RXUFH
*RRJOH(DUWK
7KHILUVWORQJWHUPQRLVHPHDVXUHPHQWZDVPDGHZHVWRI%HWDEHO593DUNDERXWIHHWIURP WKH HGJH RI 86 +LJKZD\
86
1RLVH PHDVXUHPHQW ORFDWLRQ /7 ZDV VHOHFWHG WR GRFXPHQWWKHGLXUQDOQRLVHOHYHOVJHQHUDWHGE\WUDIILFDORQJ86DQGWRUHSUHVHQWH[LVWLQJ Figure 3.12-2
Noise Measurement Locations
0 1
Mile N
SOURCE: Illingworth & Rodkin, Inc. Sargent Quarry Environmental Noise Assessment, SCC Sargent Quarry Santa Clara County, CA. February 9, 2017
SFO/19xxxx/D191577.00 - SCC Sargent Quarry/05 Graphics-GIS-Modeling/Illustrator

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-12 ESA / D201901577.01
Draft EIR July 2022
Additionally, there is one noise-sensitive residence located along the routes proposed to be widened and/or repaved on Old Monterey Road and the private access road. This residence is located immediately north of the southbound U.S. 101 off-ramp to Old Monterey Road, approximately 400 feet from the northernmost roadway improvements (measurement location LT-3 in Figure 3.12-2). This residence would be approximately 6,000 feet from the proposed

0.25-mile-long acceleration lane for trucks accessing northbound U.S. 101 that would be installed as part of the Project on the east side of the Sargent Ranch on-ramp to U.S. 101 and approximately 7,000 feet from the proposed widening and repaving of the Sargent Ranch undercrossing of U.S. 101.

Three short-term noise measurements were made in areas surrounding the quarry site between 9:00 a.m. and 10:00 a.m. A summary of the results of the short-term measurements is shown in Table 3.12-5.

TABLE 3.12-5

SHORT-TERM NOISE DATA
Location L1 L10 L50 L90 Lmax Leq Noise Sources (Lmax)
ST-1: Entrance to Quarry (see
LT-3)
66 64 62 59 67 62 U.S. 101 and local traffic on
Old Monterey Road
ST-2: Northeast corner of
Betabel RV Park (see LT-2)
59 55 51 48 62 52 U.S. 101 and ramps, distant
heavy equipment 59 54 51 49 59 52
ST-3: Homes along SR 129,
(see LT-1)
76 72 62 42 78 68 Traffic on SR 129
SOURCE: Appendix J.1.

3.12.4 Impact Evaluation

3.12.4.1 Approach to the Analysis
The following describes the methodology used to evaluate the impacts of Project site development relative to the significance criteria listed in Section 3.12.4.2.

Increase in Noise in Excess of Established Standards
The first significance criterion examines whether Project construction and/or operation would generate noise in excess of established noise standards, which are different for stationary, mobile, and construction noise sources. Project construction- and reclamation-related noise was evaluated based on County noise ordinance standards for affected properties for both mobile and stationary equipment. These standards are presented in Table 3.12-3. Increases in ambient noise levels from stationary sources during Project operation were evaluated in relationship to the General Plan policies and noise ordinance limits provided in Section 3.12.2, Regulatory Setting. The contribution of the Project to localized increases in traffic-generated noise along roadways (Impact 3.12-1c) was considered relative to published measures of substantial increases in transportation noise, as discussed below. Each of these approaches is described further below.

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-13 ESA / D201901577.01
Draft EIR July 2022
Construction Noise
The County of Santa Clara Code Chapter VIII, Section B11-154(b)(6) establishes quantitative noise standards for construction noise, which are presented in Table 3.12-3. Project construction would include the processing plant, the conveyor belts, roadway widening and repaving, internal access roads including construction of bridges over two creeks, and the proposed new acceleration lane for trucks accessing northbound on U.S. 101. Construction of these components would be temporary, occurring over approximately 9 months. All construction activities would take place between 7:00 a.m. and 5:00 p.m., Monday through Saturday, consistent with the County Code Section B11-154(b)(6). While mining and reclamation activities are similar to construction activities in terms of equipment used, they would be ongoing throughout the life of the Project, and are therefore, assessed as operational noise sources.

Construction-related noise levels were estimated for a peak construction scenario using the offroad equipment inventory provided by the Applicant for each of the construction projects mentioned above. Noise levels were calculated for the closest receptor at a variety of distances using the Roadway Construction Noise Model of the Federal Highway Administration (FHWA 2006). The analysis also uses the general assessment methodology for assessing construction noise impacts published by the Federal Transit Administration (FTA) (FTA 2018). The FTA methodology calls for estimating a combined noise level from the simultaneous operation of the two noisiest pieces of equipment expected to be used in each construction phase. This method applies usage factors to each piece of equipment analyzed to account for the time that the equipment is in use over the specified time period. Estimated noise levels at the nearest receptor are then compared to the quantitative standards for construction noise presented in Table 3.12-3 to assess significance.

Stationary-Source Noise
Mining, processing, and reclamation activities would result in a significant noise impact if exterior noise levels generated by the Project would exceed noise ordinance limits presented in Table 3.12-2. Additionally, the County’s Surface Mining requirements include restrictions on loading point locations (no closer than 30 feet to any property line), restrictions on blasting activities, and inclusion of any noise attenuation measures necessary to meet the noise ordinance limits. A three-dimensional noise propagation model (SoundPLAN Version V7.4) was used to calculate noise levels assuming full operation of each of the four mining phases.

Project-Generated Traffic Noise
The County of Santa Clara does not establish thresholds for assessing Project impacts due to increased traffic noise. Guidance on the significance of transportation-related changes to ambient noise levels is provided by the 1992 findings of the Federal Interagency Committee on Noise (FICON), which assessed the annoyance effects of changes in ambient noise levels caused by aircraft operations (FICON 1992). The recommendations are based on studies that relate aircraft noise levels to the percentage of persons highly annoyed by the noise. Although the FICON recommendations were specifically developed to assess aircraft noise impacts, they apply to all sources of transportation noise described in terms of cumulative noise exposure metrics such as the Ldn.

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-14 ESA / D201901577.01
Draft EIR July 2022
Table 3.12-6 presents criteria based on the FICON findings, which show that as ambient noise levels increase, a smaller increase in decibel levels is sufficient to cause significant annoyance. In other words, the quieter the ambient noise level, the more the noise can increase (in decibels) before it causes significant annoyance. The 5 dBA and 3 dBA noise level increases listed in Table 3.12-6 also correlate directly with noise level increases that Caltrans considers to represent “readily perceptible” and “barely perceptible,” respectively, for short-term noise increases (Caltrans 2013).

Thus, the significance of permanent increases in transportation noise levels is evaluated based on the increases identified in Table 3.12-6, below.

TABLE 3.12-6

MEASURES OF A SUBSTANTIAL INCREASE IN TRANSPORTATION NOISE EXPOSURE Ambient Noise Level without Project (DNL)
Significant Impact Assumed to Occur if Project Site
Development Increases Ambient Noise Levels by:
<60 dB + 5.0 dB or more
60–65 dB + 3.0 dB or more
>65 dB + 1.5 dB or morea
NOTES:
dB = decibels; DNL = day-night average noise level
a According to the Federal Interagency Committee on Noise report, the 1.5 A-weighted decibel (dBA) increase in environments that exceed 65 dBA is not necessarily a significant increase but, rather, an increase warranting further investigation.

SOURCE: FICON 1992.

Traffic noise levels were modeled using the algorithms of the Traffic Noise Model of the Federal Highway Administration based on existing and proposed traffic volumes provided by Hexagon Transportation Consultants (Appendix K). The resulting Project traffic noise levels were then compared to the modeled existing traffic noise conditions to determine if there would be an increase in ambient noise levels that could result in a significant impact (Appendix J.4).

Groundborne Vibration
Impacts from groundborne vibration during Project site construction and mining operations are assessed in Impact 3.12-2 using vibration-damage threshold criteria expressed in PPV for architectural damage. Equipment or activities that typically generate continuous vibration include but are not limited to excavation equipment, static compaction equipment, vibratory pile drivers, pile-extraction equipment, blasting, and vibratory compaction equipment.

Construction and operational vibration impacts are analyzed in terms of the potential of miningrelated vibrations to result in damage to nearby structures or buildings as established by Caltrans (Caltrans 2020). The Caltrans thresholds for potential architectural damage due to groundborne vibrations is 0.5 in/sec PPV for new residential structures and modern commercial buildings and

0.25 in/sec PPV for historic and older buildings.

Vibration impacts were estimated using reference vibration levels for construction equipment in concert with the vibration propagation equations published by FTA (FTA 2018) and estimating the potential for resultant vibration levels in excess of criteria established by Caltrans (Caltrans 2020).

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-15 ESA / D201901577.01
Draft EIR July 2022

3.12.4.2 Significance Criteria
Consistent with CEQA Guidelines Appendix G, the Project would result in a significant impact on noise and vibration if it would:
a) Generate a substantial temporary or permanent increase in ambient noise levels in the vicinity of the project in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies;
b) Generate excessive groundborne vibration or groundborne noise levels; or c) For a project located within the vicinity of a private airstrip or an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, expose people residing or working in the project area to excessive noise levels.

For criterion (a), a significant impact would occur if the noise levels identified in Table 3.12-6 would be exceeded.

Due to the nature of the Project, the following criterion is not analyzed in this section for the reasons described below:
• For a project located within the vicinity of a private airstrip or an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, expose people residing or working in the project area to excessive noise levels. The FAA states airports are considered compatible with all land uses when aircraft noise effects are less than 65 decibels (dB) CNEL (14 CFR Section 150 Appendix A to Part 150 Section A150.101(d)). The closest airports to the Project are the Frazier Lake Airpark, located approximately 5 miles east, the Hollister Municipal Airport, located approximately 7 miles southeast, and the South County Airport (San Martin), located approximately 11 miles north of the site. The Santa Clara County Airport Land Use Commission’s Comprehensive Land Use Plan for South County Airport indicates that the Project site is not located in the Airport Influence Area (County of Santa Clara 2020). The Project site is also outside of the influence areas and 65 dB CNEL contours for the Frazier Lake Airpark and the Hollister Municipal Airport (San Benito County Airport Land Use Commission, 2012 and 2019).

Because the Project site is located outside of the 65 dB CNEL for these airports, no Projectspecific or cumulative impacts would occur.

3.12.4.3 Project Impacts
Impact 3.12-1: Project construction would result in temporary increases in ambient noise levels in the Project vicinity. (Less than Significant) This impact addresses Significance Criterion (a) with respect to temporary noise increases due to construction.

Construction
All construction activities would take place between 7:00 a.m. and 5:00 p.m., Monday through Saturday. The Roadway Construction Noise Model was used to estimate noise generated by construction activities. Construction noise levels were calculated for each construction project based on the equipment list provided in Table 2-2 in Chapter 2, Project Description.

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-16 ESA / D201901577.01
Draft EIR July 2022
Table 3.12-7 presents the results of the construction noise modelling effort showing the predicted noise levels at the nearest sensitive land uses. Project construction closest to a sensitive receptor would be the repaving of Old Monterey Road, the northern portion of which is approximately 400 feet from the nearest receptor. All other construction projects would be 3,000 feet or greater from the nearest receptors. As shown in Table 3.12-7, daytime noise levels would range from 60 dBA at the residence closest to the processing plant to 64 dBA at the residence closest to the Old Monterey Road improvements. The increase over existing noise levels at sensitive receptors would range from 0 to 2 dBA. Because the noise levels would be below the County’s daytime standard for mobile construction equipment of 75 dBA Leq at the nearest receptors, construction noise would be less than significant.

Mitigation: None required.

Significance: Less than Significant
_________________________
Impact 3.12-2: Project operations would permanently increase ambient noise levels in the vicinity of the Project. (Less than Significant)
This impact discussion addresses Significance Criterion (a) with respect to Project operations and reclamation.

Operation
Mining Pits
Mining operations are proposed to occur year-round between the hours of 6:00 a.m. and 5:00 p.m.

Mining equipment would include excavators, dozers, trucks, graders, and loaders.

SoundPLAN version V7.4 was used to calculate noise levels during Project operation. Because mining equipment typically generates steady noise levels while in operation, the most restrictive noise limit for the purposes of this assessment is the L50 (the noise level exceeded 30 minutes in any hour). For steady noise, the L50 noise limit is the lowest noise limit and would be exceeded before any of the other noise limits contained in the County code (L25, L08, or L02 limits).

The L50 noise levels generated assuming peak operating conditions (i.e., 10 hours per day, 310 days per year) were calculated for each phase of operation at each of the nearest noise-sensitive receptor locations. To be conservative, simultaneous operation of all proposed mining equipment at each of the mining sites was assumed during peak operation of each phase of the Project:
• CAT Dozer (1);
• CAT Excavator (1);
• CAT Haul Truck (2);
• CAT Wheel Loader (1); and
• CAT Motor Grader (1).

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-17 ESA / D201901577.01
Draft EIR July 2022
TABLE 3.12-7

DAYTIME NOISE LEVELS FROM CONSTRUCTION PROJECTS
Representative
Receptor
Existing Daytime
Noise Level
(dBA Leq)a
Two Loudest
Noise Sources
Reference Noise
Level (dBA)a
Distance to
Receptorb (feet)
Usage
Factor
Adjusted Leq
Level (dBA)c
Exceed 75 dBA
daytime
standard?
Existing +
Construction Resultant
Noise Level (dBA)d
Roadway Improvement: Old Monterey Road
Bulldozer 82 400 40% 60 No
Residence F 62 Roller 80 400 20% 55 No
Combined Total 61 No 64
U.S. 101 Acceleration Lane Construction
Bulldozer 82 6,000 40% 36 No
Residence F 62 Roller 80 6,000 20% 31 No
Combined Total 37 No 62
Processing Plant Construction and Tar Creek Bridge Construction Crane 81 3,000 16% 37 No
Residence E 60 Excavator 81 3,000 40% 41 No
Combined Total 43 No 60
NOTES:
a Lmax at 50 feet
b Distance between approximate location of equipment and property line of receptor. c The Leq level is adjusted for distance and percentage of usage. d Logarithmic sum of existing noise level and construction equipment contribution is the resultant noise level.

SOURCE: Appendix J.1.

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-18 ESA / D201901577.01
Draft EIR July 2022
Additionally, as a conservative assumption, equipment was assumed to operate on the top of the existing grade. As each area is mined, additional shielding would be provided by the surrounding terrain, resulting in lower noise levels than those predicted below.

The analysis focuses on the six nearest residential receptors and the Betabel RV Park shown in Figure 3.12-3. The modeled operational noise levels at the nearest receptors are shown in Table 3.12-8, along with the measured ambient traffic noise levels. Noise level increases above existing ambient levels are shown in Table 3.12-9. For a visual presentation of the data as noise contours generated by each mining phase, see Figures 5 through 8 in Appendix J.1.

Mining-related noise levels would be 46 dBA or less at noise-sensitive receptors for all four mining phases and processing operations in the vicinity of the Project during operation, with most operations generating noise levels below 30 dBA at these receptors. When these noise levels are added to existing modeled ambient noise levels, there would be little or no change in perceptible noise. At one receptor, there would be no measurable change in ambient noise levels. In one case there would be slight increase: 1 dBA at Betabel RV Park during Phase 4 mining.

Noise generated by Project mining operations of 46 dBA, L50 would be well below ambient noise levels and below the most conservative daytime 55 dBA L50 criterion for one- and two-family residences.

Mining operations would also be conducted during the “nighttime” hours of 6:00 a.m. to 7 a.m.

The applicable exterior noise standard for noise limit for one- and two-family residences during nighttime hours is 45 dBA L50 unless the existing ambient noise level already exceeds this standard. Section B11-153(3) of the County Code provides that, if the measured ambient level exceeds that permissible level, the allowable noise exposure standard will be increased in five dB increments to encompass or reflect the ambient noise level. As indicated in Table 3.12-8, the existing ambient noise levels exceed 45 dBA, L50 at all receptor locations. The lowest existing ambient level recorded was at Betabel RV Park with a 24-hour average L50 of 52 dBA and an average L50 during the 6:00 a.m. to 7:00 a.m. hour of 56 dBA. Therefore, per Section B11-153(3) of the County Code, adding 5 dBA increments to encompass the existing ambient noise level results in an applicable noise standard would be 55 dBA, L50.which is the same as the daytime standard. Noise generated by Project mining operations of 46 dBA, L50 would be well below ambient noise levels and below the applicable nighttime 55 dBA L50 criterion for one- and twofamily residences.

As indicated in Table 3.12-9, Project operation would not result in substantial increases in the noise environment at sensitive receptors above existing noise levels during either daytime hours or the 6:00 a.m. to 7:00 a.m. nighttime work hour (increases would be 1 dBA or less). As stated above in Section 3.12.1.1, it is widely accepted that the average healthy ear can barely perceive changes in the noise level of 3 dBA. Therefore, while mining of the closest points of the Phase 4 area would exceed the 45 dBA L50 nighttime criterion, the resultant 1 dBA increase over existing ambient noise levels would not be noticeable to the nearest potentially impacted receptor (Betabel RV Park) and, consequently not represent a significant noise impact.

RES.-A
RES.-B
RES.-E
RES.-F
RES.-C
RES.-D
BETABLE RV PARK RES.-A
RES.-B
RES.-E
RES.-F
RES.-C
RES.-D

BETABLE RV PARK
SOURCE: Illingworth & Rodkin, Inc. Sargent Quarry Environmental Noise Assessment, Santa Clara County, CA. February 9, 2017; Google Earth
SFO/19xxxx/D191577.00 - SCC Sargent Quarry/05 Graphics-GIS-Modeling/Illustrator SCC Sargent Quarry
Figure 3.12-3
Receptor Locations
0 2000
Feet
N
Project Boundary
Receptor Location

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-20 ESA / D201901577.01
Draft EIR July 2022
TABLE 3.12-8

AMBIENT AND OPERATIONAL NOISE LEVELS (DBA)
Receptor
Ambient
Noise
Levels
Processing
Plant Phase 1 Phase 2 Phase 3 Phase 4
Project Operational Noise Levels, L50
Betabel RV Park 52a 30 26 28 31 46
Residence A 65 23 17 22 30 33
Residence B 55 25 19 22 34 32
Residence C 66 17 13 11 24 30
Residence D 53 41 37 31 30 30
Residence E 68 25 21 22 33 30
Residence F 71 31 24 26 10 15
NOTES:
a This is the average L50 noise level over a 24-hour monitoring period. The ambient noise level during the 6 a.m. to 7 a.m. hour was recorded to be 56 dBA, L50 during two separate days. This is higher than the 24-hour average likely as a result on morning peak hour traffic.

SOURCE: Appendix J.1.

TABLE 3.12-9

OPERATIONAL NOISE LEVELS AND INCREASES OVER AMBIENT CONDITIONS (DBA) Receptor
Ambient
Noise
Levels
Ambient +
Processing
Plant
Ambient +
Phase 1 +
Processing
Plant
Ambient +
Phase 2 +
Processing
Plant
Ambient +
Phase 3 +
Processing
Plant
Ambient +
Phase 4 +
Processing
Plant
Ambient + Operational Noise Levels, L50
Betabel RV Park 52 52 52 52 52 53
Residence A 65 65 65 65 65 65
Residence B 55 55 55 55 55 55
Residence C 66 66 66 66 66 66
Residence D 53 54 53 53 53 53
Residence E 68 68 68 68 68 68
Residence F 71 71 71 71 71 71
Significant Impact? No No No No No
Project Increase Over Ambient Conditions
Betabel RV Park -- 0 0 0 0 1
Residence A -- 0 0 0 0 0
Residence B -- 0 0 0 0 0
Residence C -- 0 0 0 0 0
Residence D -- 0* 0 0 0 0
Residence E -- 0 0 0 0 0
Residence F -- 0 0 0 0 0
NOTES:
* Noise levels are rounded to the nearest decibel. 53.5 (54) - 53.2 (53) = 0.3 (0) SOURCE: Appendix J.1.

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-21 ESA / D201901577.01
Draft EIR July 2022
As discussed below in the next subsection, processing plant operation would generate additional noise levels of 41 dBA or less at noise-sensitive receptors, and this additional noise contribution from the simultaneous operation of the processing plant would not further increase the noise contributions from mining operations at any of the four phase locations, particularly given existing ambient highway noise at the receptors nearest the processing plant.

Table 3.12-8 further indicates that L50 levels resulting from the proposed Project would be 6 dBA lower than ambient levels at Betabel RV Park under processing and mining operations and as much as 61 dBA lower than ambient levels at the most distant receptors analyzed.

Lmax levels of quarry equipment, which are typically about 10 dBA higher than L50 levels, would also be well below the County thresholds of 75 dBA Lmax during the daytime and 65 dBA Lmax at night at the residence locations.

The Project would be consistent with County of Santa Clara General Plan Policy C-HS 25 and Implementation Strategies C-HS(i) 23 (Project design review) and C-HS(i) 26 (Require projectspecific noise studies to assess actual and projected dB noise contours for proposed land uses likely to generate significant noise) because the above acoustical analysis and the detailed acoustical study in Appendix J.1 demonstrate that the Project would not exceed the applicable thresholds at sensitive receptors. Further, operation of the mining pits would be consistent with the County’s surface mining requirements established in Section 4.10.370 of the County of Santa Clara Zoning Code, which restricts loading point locations to no closer than 30 feet to any property line. As a result, the Project impact with respect to operation of the mining pits would be less than significant.

Processing Plant
During mining operations, excavated sand and gravel would be hauled via the conveyor belts to the processing plant. Excavated material would be mechanically sized, washed, sorted into stockpiles, and prepared for shipping at the processing plant. Some materials also would be crushed and sorted into stockpiles via radial stacker and conveyors. A total of 30 pieces of equipment would operate at the processing site, including hoppers, crushers, screens, conveyors, and stackers.

The noise levels shown in Tables 3.12-8 and 3.12-9 present the predicted noise levels and noise level increases associated with operation of the processing plant. These noise levels represent a conservative scenario for the operation of the processing plant, with all proposed processing equipment operating simultaneously, for a total of 30 individual pieces of equipment inclusive of conveyor systems. As shown in Tables 3.12-8 and 3.12-9, operation of the processing plant would not increase noise levels over ambient conditions at the sensitive receptors, with one exception.

There would be a slight, imperceptible increase (0.3 dBA) at Residence D. Noise levels generated by operation of the processing plant would be below the applicable 55 dB, L50 exterior noise criteria of the County Code for daytime and nighttime operations. Processing plant operation would generate additional noise levels of 41 dBA or less at noise-sensitive receptors and this additional noise contribution from the simultaneous operation of the processing plant would not further increase the noise contributions from mining operations discussed above at any of the four phase locations, particularly given existing ambient highway noise at the receptors nearest the

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-22 ESA / D201901577.01
Draft EIR July 2022
processing plant. Because it would not substantially increase noise levels at sensitive receptors, the impact of operation of the processing plant would be less than significant.

Project Traffic
Based on the traffic volumes provided by Hexagon Transportation Consultants (Appendix K), the 2017 noise analysis prepared by Illingworth & Rodkin (Appendix J.1) estimated that during peak quarry operations, the Project could result in up to 40 one-way truck trips during morning peak traffic hour to U.S. 101. A smaller number of Project trips would be added to SR 25.

At the time that the noise analysis was prepared in February 2017, U.S. 101 carried approximately 4,140 vehicle trips per peak hour, about 7.5 percent of which were trucks, and SR 25 carried about 2,200 vehicle trips per peak hour, with about 6.5 percent trucks, which represent pre-pandemic traffic volumes. Traffic noise levels were modeled using the algorithms of the Federal Highway Administration’s Traffic Noise Model for the existing and existing-plus-Project scenarios.

Assuming 100 percent of all truck trips allocated to U.S. 101 and 20 percent to SR 25 as indicated in the transportation analysis (Appendix K), roadside noise levels along U.S. 101 and SR 25 would increase by 0.3 dBA and 0.1 dBA, respectively. Therefore, the Project’s additional peakhour trips would generate a minor increase in traffic volumes along U.S. 101 and SR 25. Because the increase over existing traffic noise levels would not be perceptible (less than 1 dBA Ldn) at sensitive receptors along roadways serving the site, this impact would be less than significant.

Noise Increase along Existing Rail Line
The Project would transport processed aggregate via rail up to three times per week (adding additional rail cars to a maximum of one train per night) along the existing Union Pacific northsouth rail line. Railcars containing Project aggregate would be attached to a train already traveling on that line, rather than requiring a new train serving only the Project. However, this analysis uses the impacts from an additional train as a proxy for increased numbers of cars on an existing train.

This analysis is conservative because an additional train would produce more noise impacts than an increased number of cars.

The southern portion of the Union Pacific’s Coast Subdivision currently carries an average of 10 passenger trains and four to six freight trains daily between San José and Gilroy, as well as two passenger trains and four to six freight trains daily between Gilroy and Salinas. The Caltrain Corridor, which travels between San José and San Francisco, currently carries an average of 96 weekday passenger trains and four freight trains daily.

Noise impacts from train movements were calculated by comparing noise from existing train movements to noise from existing plus mining-related train movements (see Appendix J.2). The criterion for assessment of rail noise assessment is the transportation noise criteria presented in Table 3.12-6, above. These criteria use the 24-hour Ldn metric, which applies a 10 dBA “penalty” to noise during the sensitive nighttime hours. Receptors potentially affected by increases in rail activity would be near monitoring locations LT-1 and LT-2, which are approximately 350 feet and 1,000 feet from the rail line, respectively. Monitored noise levels at these locations ranged from 59 to 62 Ldn (refer to Table 3.12-3). Consequently, based on the

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-23 ESA / D201901577.01
Draft EIR July 2022
criteria presented in Table 3.12-6, a 3 dBA increase in noise levels would conservatively be considered a significant noise impact from transportation sources at these locations.

Long-term monitoring of noise adjacent to the rail line at monitoring location LT-1 indicates three separate noise events commensurate with rail activity between midnight and 3:00 a.m. on a Thursday and two events on a Friday. Based on the conservative assumption that the Project would add one additional nighttime rail operation, the rail noise analysis in Appendix J.2 indicates that the additional nighttime rail operation would increase the existing noise level by 2 dBA Ldn, conservatively assuming existing conditions of two daytime and two nighttime pass-by events. Therefore, increased rail activity would have a less than significant noise impact to receptors in the vicinity of the Project site.

Rail Spur
Connection of the loaded rail cars to a locomotive would occur on the proposed rail spur three time per week in a process that takes approximately 30 minutes. These slow rail car movements by locomotive would occur approximately 5,000 feet from the nearest receptor (Residence E).

The CREATE Noise Model of the Federal Railroad Administration was used to estimate noise at this receptor from locomotive movements on the proposed rail spur (see Appendix J.3).

Assuming locomotive operations of 20 miles an hour, locomotive noise on the spur would result in a noise level of 35 dBA, Leq at this nearest receptor. As shown in Table 3.12-8, the existing ambient at this receptor is 68 dBA. The addition of rail noise at this receptor would not increase the existing noise level at this receptor which is dominated by traffic on U.S.101. Therefore, noise generated by locomotive movements along the proposed rail spur would be less than significant.

Noise Impacts from All Project Operations
The Project would generate noise from mining of aggregate at the four mining areas, from operation of the processing plant, from increased rail cars on existing trains operations and increased haul truck traffic on local highways. While the County Code does not have the authority to regulate transportation sources such as truck and rail operations, the combined noise increase contribution of all these sources can be summed and the resultant noise increase over ambient levels evaluated for perceptibility at the nearest receptors. As indicated in Table 3.12-9, the combination of noise from mining of aggregate and from operation of the processing plant would increase existing noise levels at only one receptor (Betabel RV Park) and the increase would be 1 dBA. As discussed above, truck traffic increases on U.S. 101 would increase roadside noise levels by 0.3 dBA.

The addition of rail cars to existing operational trains to transport aggregate would not increase noise levels, but rather increase the duration of train pass-by events at receptors along the rail line that would not be expected to result in a perceptible increase in noise levels. As discussed above, locomotive noise on the rail spur would result in a noise level of 35 dBA, Leq at the nearest receptor, which would not increase the existing noise level at this receptor which is dominated by traffic on U.S.101. Therefore, the maximum noise increase at any one receptor would be approximately 1.3 dBA which would be a less than 3 dBA increase and the operation of cumulative Project sources would be less than significant.

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-24 ESA / D201901577.01
Draft EIR July 2022
Reclamation
Reclamation activities would occur at the end of mining in each phase, and intermittently for 5 years subsequent to each phase of mining. The location and equipment involved in regrading to achieve the final contours would be similar to that involved with quarrying of the mining pits.

Therefore, the noise generated by reclamation activities would be similar to that presented for noise generated by the mining phases in Tables 3.12-8 and 3.12-9 and would not meaningfully contribute to an increase in noise levels at the nearest sensitive receptor. Revegetation and monitoring, which would occur sporadically for 5 years after the close of each phase, would involve up to two employees at one time, and would not require the use of heavy equipment. For these reasons, the noise impact from reclamation activities would be less than significant.

Summary
Noise levels from operation of the Project, including the processing plant, mining, rail line and traffic, would not exceed the applicable noise standards Therefore, the impact would be less than significant.

Mitigation: None required.

Significance: Less than significant
_________________________
Impact 3.12-3: Use of conventional earth moving equipment during construction, operation, and reclamation could generate groundborne vibration and groundborne noise levels. (Less than Significant)
This impact addresses Significance Criterion (b).

Construction, Operation, and Reclamation
The Project does not propose the use of blasting or other mining techniques that might result in significant levels of vibratory impacts. The Project would employ conventional earth moving equipment as part of both construction and mining operations, for which vibration levels are shown below in Table 3.12-10.

TABLE 3.12-10

VIBRATION SOURCE LEVELS FOR EQUIPMENT
Equipment PPV at 25 feet (in/sec)
Clam Shovel Drop 0.202
Vibratory Roller Compactor 0.21
Hoe Ram 0.089
Loaded Trucks 0.076
Jackhammer 0.035
Bulldozer 0.003
SOURCE: FTA 2018.

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-25 ESA / D201901577.01
Draft EIR July 2022
Use of heavy equipment, such as a vibratory roller or a clam shovel, would generate vibration levels of up to 0.21 in/sec PPV at a distance of 25 feet, which is below the Caltrans thresholds for potential architectural damage due to groundborne vibrations of 0.5 in/sec PPV for new residential structures and modern commercial buildings and 0.25 in/sec PPV for historic and older buildings. The nearest sensitive receptors are located approximately 400 feet from Project construction (Old Monterey Road Improvements), and approximately 1,600 feet from Project operation. At these distances, vibration levels would be attenuated to well below the Caltrans thresholds for potential architectural damage to new residential structures, modern commercial buildings, and historic and older buildings. Consequently, vibration impacts from construction, operation, and reclamation would be less than significant.

Mitigation: None required.

Significance: Less than significant
_________________________

3.12.4.4 Cumulative Analysis
As stated in Section 3.1, the geographic scope for the noise and vibration analysis is the Project site and adjacent parcels.

Impact 3.12-4: The Project would not result in a cumulatively considerable contribution to a significant noise or vibration impact. (Less than Significant) The geographic scope of analysis for cumulative noise and vibration construction impacts encompasses sensitive receptors within approximately 1,000 feet of the Project site.4 Beyond 1,000 feet, the contributions of noise from other projects would be greatly attenuated through both distance and intervening structures and their contribution would be expected to be minimal.

There is only one project within in the geographic scope of the cumulative noise impact analysis:
the U.S. 101 Widening Upgrade Project. This project would widen U.S. 101 to six lanes between Gilroy and SR 129 in San Benito County, reconstruct the U.S. 101/SR 25 interchange, extend Santa Teresa Boulevard from Castro Valley Road to the U.S. 101/SR 25 interchange, improve the southbound U.S. 101 off-ramp at SR 129, grade-separate the Union Pacific Rail crossing on SR 25 west of Bloomfield Avenue, and construct bicycle facilities.

The widening of U.S. 101 could increase noise levels at the Betabel RV Park (at the vicinity of monitoring location LT-1). The May 2013 FEIR for the U.S. 101 Improvement Project from Monterey Street to S.R. 129 analyzes the noise impact of this freeway widening project during 4 This screening threshold distance was developed based on stationary source noise attenuation equations (Caltrans 2013) and the combined noise level generated by typical construction phases for a given project (assuming multiple pieces of equipment) at a distance of 50 feet. Using the attenuation equations, the maximum noise level of 89 dBA for both excavation and finishing would diminish to below 65 dBA at 1,000 feet. A receptor experiencing noise levels of 89 dBA from two adjacent construction sites would experience a cumulative noise level of 91 dBA (the acoustical sum of 89 dBA plus 89 dBA), which would still be below 65 dBA at 1,000 feet which, hence, is used as the geographic scope.

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-26 ESA / D201901577.01
Draft EIR July 2022
peak traffic hours (SCVTA, 2013). This document indicates that the resultant peak hour noise levels at the Betabel RV Park would increase to 60 dBA at the most westerly receptor analyzed for that project, approximately 280 feet from the highway. Using line source noise propagation, this noise contribution would decrease to 55 dBA at Receptor LT-1 (analyzed above in Impact 3.12-2), approximately 830 feet from the freeway. Given that the existing peak hour noise level monitored at LT-1 during the peak traffic hour 55 to 56 dBA (Illingworth and Rodkin, 2017), the widening of U.S. 101 would not further increase noise impacts at LT-1. As LT-1 is the only receptor that would experience an increase in noise level from project quarrying activities, as indicated in Table 3.12-9, quarrying operations would not result in a cumulatively considerable contribution at any of the other receptors analyzed above in impact 3.12-2.

In addition, under cumulative conditions, traffic volumes on U.S. 101 and SR 25 would increase, which would increase traffic noise levels along those roadways. Cumulative traffic noise levels for year 2040 were modeled based on traffic volumes provided by Hexagon Transportation Consultants (Appendix K) including the addition of Project traffic. The difference in roadside noise levels between the cumulative-plus-Project scenario and existing conditions would be

1.2 dBA Ldn along U.S.101 and 1.0 dBA Ldn along SR 25. This cumulative noise increase would be less than 3 the dBA Ldn threshold, so the cumulative traffic noise impact would be less than significant.

In combination, the increase noise from cumulative traffic volumes and reducing the distance to U.S. 101 from Betabel RV Park would result in an increase of 1.4 dBA Ldn at the Betabel RV Park receptors closest to U.S. 101. This cumulative noise increase would be less than the 3 dBA Ldn threshold, and Project would contribute only slightly to cumulative traffic levels, so the cumulative traffic noise impact would be less than significant, and the Project’s contribution would not be cumulatively considerable, considering both the widening of U.S. 101 and future increases in traffic volumes.

With respect to rail use, there are no cumulative projects in the vicinity of the Project site that would add to rail activity. The cumulative roadway traffic noise increase described above from the widening and cumulative traffic would add an estimated 1.4 dBA Ldn at the Betabel RV receptor to U.S. 101. However, the receptors nearest to the rail line are another 500 feet from U.S. 101, and these noise contributions from the highway would be attenuated by intervening RVs.

As discussed in Impact 3.12-3, the nearest sensitive receptors are located approximately 400 feet from Project construction (Old Monterey Road Improvements) which would be a more than sufficient distance for vibration propagation to reduce resultant vibration levels to below the building damage thresholds. Unlike the analysis for average noise levels, in which noise levels of multiple pieces of equipment can be combined to generate a maximum combined noise level, instantaneous peak vibration levels do not combine in this way. Vibration from multiple construction sites, even if they are located close to one another, would not combine to raise the maximum PPV. For this reason, the cumulative impact of construction vibration from the project and the U.S. 101 Widening Upgrade Project (were they to occur simultaneously and near one another) would generally not combine to further increase vibration levels. In essence, vibration

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-27 ESA / D201901577.01
Draft EIR July 2022
effects are highly localized Therefore, the cumulative vibration impact would be less than significant, and the Project’s contribution would not be cumulatively considerable.

For these reasons, the Project’s contribution to cumulative noise and vibration impacts would not be cumulatively considerable and would therefore be less than significant.

Mitigation: None required.

Significance: Less than significant
_________________________

3.12.5 References
Caltrans. 2013. Technical Noise Supplement (TeNS) to the Traffic Noise Analysis Protocol, pp. 2–44, September. Available online at: https://dot.ca.gov/-/media/dot-media/programs/ environmental-analysis/documents/env/tens-sep2013-a11y.pdf. Accessed March 15, 2021.

Caltrans. 2020. Transportation and Construction Vibration Guidance Manual, April. Available online at: https://dot.ca.gov/-/media/dot-media/programs/environmental-analysis/ documents/env/tcvgm-apr2020-a11y.pdf. Accessed March 15, 2021.

County of Santa Clara. 1994. General Plan Safety and Noise Element.

County of Santa Clara. 2020. Comprehensive Land Use Plan, San Martin Airport, September 10, 2008, Amended November 2020.

Federal Highway Administration (FHWA). 2006. Roadway Construction Noise Model version1.1, December 8, 2006.

Federal Interagency Committee on Noise (FICON). 1992. Federal Agency Review of Selected Airport Noise Analysis Issues, August.

Federal Transit Administration (FTA). 2018. Transit Noise and Vibration Impact Assessment, September.

Hexagon Transportation Consultants. 2017. Sargent Quarry Project, Transportation Impacts Analysis, February.

Illingworth & Rodkin, Inc. 2017. Sargent Quarry Environmental Noise Assessment, Santa Clara County, CA. February 9.

Illingworth & Rodkin, Inc. 2019. Noise Analysis of Rail Spur Alternative for Sargent Quarry, Santa Clara County, CA. February 28.

San Benito Airport Land Use Commission. 2019. Airport Land Use Compatibility Plan, Frazier Lake Airpark, December 19, 2019.

San Benito Airport Land Use Commission. 2012. Hollister Municipal Airport Land Use Compatibility Plan, June 12, 2012.

3. Environmental Setting, Impacts, and Mitigation

3.12 Noise
Sargent Quarry 3.12-28 ESA / D201901577.01
Draft EIR July 2022
Santa Clara Valley Transportation Authority (SCVTA). 2013. Final Environmental Impact Report, U.S. 101 Improvement Project between Monterey Street and State Route 129. May 2013. https://www.vta.org/sites/default/files/2020-06/2013_FinalEIR_US101- Improvement_MontereySt-SR129_FullDocument_0.pdf. Accessed March 22, 2021.

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-1 ESA / D201901577.01
Draft EIR July 2022

3.13 Transportation

3.13.1 Introduction
This section addresses the impacts of the Project on transportation. This includes discussion of any inconsistency with plans, ordinances, and policies governing the circulation system; vehicle miles traveled (VMT); hazards from geometric design features; and emergency access. The section first describes the existing environmental setting for transportation facilities and the applicable regulatory framework, then describes the approach to the analysis and evaluates the transportation impacts of Project construction and operation. Mitigation measures are identified if feasible to avoid or reduce significant impacts.

The information in this section is based in part on a Transportation Impact Analysis (TIA) prepared by Hexagon Transportation Consultants, Inc. in February 2017,1 and a Construction Traffic Impact Evaluation prepared by Hexagon Transportation Consultants, Inc. in March 2021. These reports are included as Appendix K to this EIR. The TIA was prepared prior to July 1, 2020, which is the date on which CEQA Guidelines Section 15064.3(b) became effective statewide and replaced the transportation metrics of delay and Level of Service (LOS) with VMT. While no longer used to determine the significance of transportation impacts, the intersection, freeway/highway segment, and freeway ramp analyses provided in the TIA may still be used as a planning tool by the County.

The County received scoping input from the California Department of Transportation (Caltrans) regarding its jurisdiction with respect to U.S. 101 and recommended approaches to the technical transportation analysis to be conducted for the Project (Appendix A). The County reviewed and considered this input in preparing the TIA and Draft EIR.

3.13.2 Regulatory Setting

3.13.2.1 Federal
There are no federal laws or regulations regarding transportation that would apply to the Project.

3.13.2.2 State
California Department of Transportation
Caltrans manages interregional transportation, including management and construction of the California highway system. In addition, Caltrans is responsible for permitting and regulation of the use of state roadways. There are several facilities that fall under Caltrans jurisdiction near the Project site, including U.S. 101, State Route (SR) 25, and SR 129. 1 Since the 2017 TIA was prepared, the estimated number of trips associated with Project sales has been reduced slightly (from 300 trips per day to 278 trips per day), and the distribution throughout the day has changed as well, with a small number of sales-related trips occurring prior to 7:00 am rather than starting at 7:00 am. As a result, the TIA analyzes a slightly higher number of daily and a.m. peak hour trips than would occur under the Project as proposed. In addition, the number of total daily trips was estimated in the TIA to be 346 total daily trips, compared to 324 daily trips under the Project as proposed. For these reasons, the analysis in the 2017 is therefore considered conservative.

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-2 ESA / D201901577.01
Draft EIR July 2022
Modifications of Caltrans facilities, such as the proposed improvements to the U.S. 101 on-ramp, must meet standards identified in the Highway Design Manual, which includes specifications for lane width, design speed, lane length, curve radii, sight distance, and other features (Caltrans 2019a).

California Department of Transportation Encroachment Permits Construction in facilities under Caltrans jurisdiction requires a Caltrans Encroachment Permit, which includes a Traffic Control Plan in compliance with the Manual on Uniform Traffic Control Devices (MUTCD) (Traffic Control Manual) (Caltrans 2014). As part of these requirements, there are provisions for coordination with local emergency services, training for flagmen for emergency vehicles traveling through the work zone, temporary lane separators that have sloping sides to facilitate crossover by emergency vehicles, and vehicle storage and staging areas for emergency vehicles. MUTCD requirements also provide for construction work during off-peak hours and flaggers.

California Department of Motor Vehicles
Drivers of vehicles weighing over 13 tons and/or with 3 axles must have a Commercial Driver License (CDL) issued by the California Department of Motor Vehicles (DMV). Therefore, most haul trucks used to transport Project products would require a CDL to operate. The DMV has developed licensing and testing requirements to ensure that the safe operation of such vehicles.

For example, all CDL drivers must know state laws limiting the size and weight of vehicles and loads and demonstrate ability to drive safely in a variety of traffic situations. In addition, DMV will revoke a CDL under certain circumstances, such as driving with a blood alcohol level of

0.04%, committing a serious traffic violation, such as excessive speeding or reckless driving, or violating the State’s cell phone and texting laws. (CDMV, 2019-2021).

Senate Bill 743
The California Natural Resources Agency adopted CEQA Guidelines Section 15064.3(b) in December 2018 to implement Senate Bill (SB) 743. These revisions to the CEQA Guidelines criteria for determining the significance of transportation impacts focus primarily on projects within transit priority areas and shift the focus from driver delay (i.e., level of service) to reduction of greenhouse gas (GHG) emissions, creation of multimodal networks, and promotion of a mix of land uses. The revisions require lead agencies to begin evaluating transportation impacts for automobiles based on VMT no later than July 1, 2020. VMT is a measure of the total number of miles driven to or from a project and sometimes is expressed as an average number of miles per trip or per person.

3.13.2.3 Regional
Plan Bay Area 2050
Plan Bay Area 2050 is a 30-year plan that provides thirty-five strategies to address housing, the economy, transportation and the environment across the Bay Area’s nine counties — Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, Solano and Sonoma. The plan was prepared by the Bay Area’s two regional planning agencies, the Metropolitan

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-3 ESA / D201901577.01
Draft EIR July 2022
Transportation Commission (MTC) and the Association of Bay Area Governments (ABAG). The final Plan was adopted by both agencies in October 2021. Because the Plan does not set specific requirements for individual projects, this EIR does not address consistency with Plan Bay Area 2050 strategies.

Valley Transportation Plan 2040
As the congestion management agency for Santa Clara County, the Santa Clara Valley Transportation Authority (VTA) is responsible for developing a long-range countywide transportation plan, called the Valley Transportation Plan (VTP) 2040 (VTA 2015). The projects included in the VTP serve as VTA’s recommendations for inclusion in Plan Bay Area, which is the region’s long-range strategic plan for transportation, housing, economy, and the environment, and the list of projects is updated on a 4-year cycle coinciding with updates to that plan. VTP 2040 provides programs, projects, and policies for roadways, transit, Intelligent Transportation Systems and Systems Operations Management, bicycle facilities, pedestrian facilities, and the integration of land use and transportation. The VTA Board of Directors adopted VTP 2040 in October 2014. The only VTP transportation project relevant to the Project is the construction of new Express Lanes on U.S. 101 between 10th Street in Gilroy and SR 25. These Express Lanes would terminate approximately 2.5 miles to the north of the Project site.

Congestion Management Program
As the congestion management agency for Santa Clara County, VTA also is authorized to set federal and state funding priorities for transportation improvements that affect the Santa Clara Congestion Management Program (CMP) transportation system. As discussed in Section 3.13.2.2, CEQA Guidelines Section 15064.3(b) requires lead agencies to evaluate transportation impacts based on VMT and no longer allows vehicle delay and LOS to be used to determine the significance of a transportation impact. Because the CMP is solely focused on vehicle delay and LOS transportation metrics, it is not discussed further in this EIR.

3.13.2.4 Local
County of Santa Clara General Plan
The County General Plan Transportation Chapter provides information about the County’s transportation needs (County of Santa Clara 1994a, 1994b). The Plan also includes LOS standards for the County. Currently, the County’s Policy C-TR 12 seeks to achieve LOS D or better, but acknowledges that this may not always be feasible. However, as explained above under Senate Bill 743, changes to LOS are not considered environmental impacts under CEQA.

Therefore, these policies are addressed only in Appendix C, General Plan Consistency, and in Appendix K.1, which analyzes the Project’s LOS impacts for the purpose of determining General Plan consistency.

The following transportation policies are included in the County’s General Plan:

Policy R-RC 78: Access to new quarry sites should make maximum use of major thoroughfares, such as expressways, freeways, and designated truck routes, avoiding

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-4 ESA / D201901577.01
Draft EIR July 2022
impacts upon local-serving routes. Where feasible, alternatives to truck transportation should be encouraged.

Policy R-TR 9: Rural roads should be designed and built to standards that will assure driving safety and provide access for emergency vehicles.

Policy R-TR 11: New development which would significantly impact private or public roads, should be allowed only when safety hazards and roadway deterioration will be mitigated to a less-than-significant level.

Policy R-TR 14: Environmental impacts of roadway construction and expansion should be mitigated to a less-than-significant level.

3.13.3 Environmental Setting

3.13.3.1 Regional Access
Regional access to the vicinity of the Project site is provided by U.S. 101 and SR 25. These facilities are described below, along with the most recently available peak hour and annual average daily traffic (AADT) volumes (Caltrans 2019b).

U.S. 101 is a north-south freeway traversing the State of California. North of the Monterey Street interchange in Gilroy, U.S. 101 is a six-lane freeway and transitions to a four-lane freeway south of that point, including in the vicinity of the Project site. Direct access to/from U.S. 101 to the vicinity of the Project site is provided via freeway ramps at Old Monterey Road. Peak hour and AADT on U.S. 101 near the Project site are approximately 6,000 vehicles and 63,000 vehicles, respectively.

SR 25 is a two-lane east-west highway that carries regional traffic between Gilroy and Hollister. It begins at its junction with U.S. 101 in Gilroy and extends southward through Hollister toward Paicines, providing regional access to/from the vicinity of the Project site to the east. The posted speed limit on SR 25 is 55 mph near its interchange with U.S. 101. Peak hour and AADT on SR 25 near the Project site are approximately 2,400 vehicles and 27,900 vehicles, respectively.

3.13.3.2 Local Access
Old Monterey Road is a two-lane north-south roadway that runs parallel to and west of U.S. 101 and provides direct access to the vicinity of the Project site. It begins at its ramps with U.S. 101, less than 1 mile south of the SR 25 overpass, and extends southward for approximately 0.5 miles to a gated entrance where it becomes a private roadway that provides access to the Project site. At its southern end, within the Project site, the private roadway extends eastward and under U.S. 101 to connect to northbound U.S. 101. For reference purposes, the private roadway that provides direct access to the Project site and to northbound U.S. 101 is referred to as the Old Monterey Road Extension. In addition to providing direct access to the Project site, Old Monterey Road also provides access to the former Freeman Quarry (now reclaimed), several farm equipment storage buildings, a fruit/vegetable stand, and a private residence.

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-5 ESA / D201901577.01
Draft EIR July 2022
Old Monterey Road is a narrow undeveloped roadway that is approximately 25 feet wide between the southbound freeway ramps and the Project site’s proposed access gate and narrows to 20 feet or less south of the access gate. The segment of the Old Monterey Road Extension east of U.S. 101 was measured to be approximately 12 feet wide. Average daily traffic (ADT) volumes on Old Monterey were obtained from 24-hour machine counts collected for the Project in September 2016. The ADT along Old Monterey Road and Old Monterey Road Extension ranged from 15 to 45 vehicles.

The U.S. 101 southbound ramps at Old Monterey Road include a 500-foot deceleration lane and a 1,000-foot acceleration lane that facilitate access between Old Monterey Road and southbound U.S. 101. The U.S. 101 northbound on-ramp at the Old Monterey Road extension is approximately 12 feet wide with no shoulders, does not include an acceleration lane, and does not meet Caltrans standards under existing conditions.

3.13.3.3 Pedestrian, Bicycle, and Transit Facilities
Because the Project site is located in a rural unincorporated area of Santa Clara County, there are no other transportation facilities (such as sidewalks, bike lanes, bike routes, or transit services) near the Project site. Due to the location and nature of the Project, all trips generated by the Project would consist of passenger vehicles and trucks.

3.13.3.4 Rail Transport
A UPRR rail line runs generally parallel U.S. 101. In the vicinity of the Project site, the rail line is located adjacent to the eastern boundary of the processing plant site. There are no rail spurs or other rail lines in the Project vicinity.

3.13.3.5 Vehicle Miles Traveled
At present, the only traffic originating on the Project site would be intermittent trips associated with the cattle operation. Such traffic is not daily, and results in negligible VMT.

A framework for analyzing VMT impacts in the unincorporated area was recently prepared for the County of Santa Clara by WSP (WSP 2021). Using the VTA’s VMT estimator tool, WSP calculated the average daily VMT per employee in rural areas to be 31.6 (WSP 2021).

3.13.4 Impact Evaluation

3.13.4.1 Approach to the Analysis
The Project would result in vehicle trips to the transportation network during Project construction and operation. In addition, it would construct the following transportation improvements, which are further described in Section 2.4.3, Site Access and Vehicle Trips, of the Project Description:
• private, internal access roadways and bridge;

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-6 ESA / D201901577.01
Draft EIR July 2022
• improvements to an existing U.S. 101 on-ramp east of Sargent Ranch to facilitate truck access;
• improvements to Old Monterey Road (i.e., new pavement and 3-foot-wide shoulders on either side of the roadway); and
• construction of a new rail spur that would connect to the existing Union Pacific Railroad (UPRR) tracks to the east of the Project site along U.S. 101.

Trip Generation
Construction
The peak of Project construction activity would occur during the concurrent construction of the Old Monterey Road improvements and the U.S. 101 northbound on-ramp acceleration lane. Each of these two construction activities would require crew sizes of up to 15 workers per day and up to 150 truck deliveries over the course of the entire 2- to 3-week overlap period. Based on the construction hours (7:00 a.m. to 5:00 p.m.), construction workers would arrive at the Project site before the a.m. peak hours (7:00 a.m. to 9:00 a.m.), but would depart the Project site during the p.m. peak hour, when traffic volumes on U.S. 101 and SR 25 would be highest.2 Truck deliveries would be made throughout the day. Based on the above, Project construction would generate a maximum of 110 daily trips (Monday through Saturday), with 6 of those trips (3 inbound and 3 outbound) occurring during the a.m. peak hour and 33 trips (all outbound trips) occurring during the p.m. peak hour (Table 1 in Appendix K.2).

Operation
Project-generated vehicular traffic was estimated based on demand, the production capacity of the processing plant, the capacity and service rate of trucks delivering material into and out of the site, the number of employees, and the hours of operation. This trip activity represents the peak months of mining operations, which would occur during the construction season between April and October. Vehicular traffic associated with aggregate sales was assumed to access the site between the hours of 4:30 a.m. and 3:30 p.m. only. Materials delivery to the Project site would occur between 8:00 a.m. and 2:00 p.m., and maintenance vehicles are assumed to arrive and depart twice a day (between 8:00 a.m. and 9 a.m. and between 2:00 p.m. and 3:00 p.m.). Project traffic generated during the p.m. peak hour is traffic associated with employees leaving the Project site at the end of the workday.

As shown in Table 3.13-1, Hourly Distribution of Project Trips, Project operation would generate an estimated total of 324 daily vehicular trips (Monday through Saturday, except for legal holidays), including employee and customer trips. The highest number of those trips 2 Generally, traffic volumes are highest from 7:00 a.m. to 9:00 a.m. and from 4:00 p.m. to 6:00 p.m. during a typical weekday. The a.m. and p.m. peak hours occur during these two peak periods. The peak hour can vary from one intersection to another. For example, the peak hour at one intersection could occur between 7:00 and 8:00 a.m., while the peak hour at another intersection occurs between 7:30 and 8:30 a.m. The traffic count data show when the peak hour for a facility occurred (Appendix K.2). The peak hour is usually used to evaluate LOS on roadway facilities and at intersections. As explained above, this EIR does not evaluate Project LOS. The peak hours are instead used to inform the extent to which Project construction or operation traffic could conflict with traffic on roadways serving the Project site.

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-7 ESA / D201901577.01
Draft EIR July 2022
(20 inbound and 20 outbound) would occur between 8:00 a.m. and 9:00 a.m., which is within the a.m. peak period. During the p.m. peak period, 15 trips (all outbound trips) would occur between 4:00 p.m. and 5:00 p.m.

TABLE 3.13-1
HOURLY DISTRIBUTION OF PROJECT TRIPSa
Hours of Operation
Passenger
Car Truck Total Site Trips
Facility
Employeesb
Aggregate
Salesc
Materials
Delivery
Maintenance
Vehicles In Out Total
4:00 a.m. to
5:00 a.m.

Arrivals 2 5
7 5 12
Departures 5
5:00 a.m. to
6:00 a.m.

Arrivals 10
10 10 20
Departures 10
6:00 a.m. to
7:00 a.m.

Arrivals 13 12
25 12 37
Departures 12
7:00 a.m. to
8:00 a.m.

Arrivals 12
12 12 24
Departures 12
8:00 a.m. to
9:00 a.m.

Arrivals 18 1 1
20 20 40
Departures 18 1 1
9:00 a.m. to
10:00 a.m.

Arrivals 18 1
19 19 38
Departures 18 1
10:00 a.m. to
11:00 a.m.

Arrivals 18 1
19 19 38
Departures 18 1
11:00 a.m. to
12:00 p.m.

Arrivals 18 1
19 19 38
Departures 18 1
12:00 p.m. to
1:00 p.m.

Arrivals 12 1
13 13 26
Departures 12 1
1:00 p.m. to
2:00 p.m.

Arrivals 8 1
9 9 18
Departures 8 1
2:00 p.m. to
3:00 p.m.

Arrivals 4 1
5 5 10
Departures 4 1
3:00 p.m. to
4:00 p.m.

Arrivals 4
4 4 8
Departures 4
4:00 p.m. to
5:00 p.m.

Arrivals
0 15 15
Departures 15
5:00 p.m. to
6:00 p.m.

Arrivals
0 0 0
Departures
Total Daily Trips: 30 278 12 4 162 162 324
NOTES:
a. Daily project area traffic activity was estimated based on the number of facility employees, hours of operation, and site activity information provided by the project applicant. The plant would be operated with 15 full-time employees and a total of 139 sales truck loads per day, and receive an average of six deliveries and two maintenance trucks per day. b. Facility employees were assumed to arrive at the site within 15 minutes before and leave within 15 minutes after proposed hours of operation (7:00 a.m. to 4:30 p.m. for most employees, with 2 to 3 employees arriving at 4:30 a.m. to assist with loading early sales trucks) c. Truck activity would occur between the hours of 4:30 a.m. and 4:00 p.m. Monday through Saturday only. The number of trucks per hour would vary as shown.

SOURCE: Freeman Associates 2021a.

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-8 ESA / D201901577.01
Draft EIR July 2022
TABLE 3.13-2

TRIP GENERATION FOR PROJECT CONSTRUCTION AND OPERATION DURING PEAK CONSTRUCTION ACTIVITY Daily Trips
(inbound and outbound combined)
Trip Generation
A.M. Peak Hour P.M. Peak Hour
Workers Trucks1 ADT in out in out
Peak Construction Traffic 60 50 110 3 3 3 33
Peak Operation Traffic 30 294 324 20 20 0 15
SOURCE: Appendix K.2.

Trip Distribution and Trip Length
The estimated peak-hour Project traffic was distributed on the area transportation network based on the primary markets for the quarry materials and the locations of nearby communities from which Project workers would be drawn. Based on information provided by the Applicant, the TIA (Appendix K.1, page 65) assumed that 80 percent of the truck traffic would travel to/from Santa Clara County with an average trip length of 40 miles, while 10 percent would travel to/from San Benito County with an average trip length of 17 miles, and 10 percent would travel to Monterey County, with an average trip length of 27 miles. Employee trips were assumed to originate primarily in the Gilroy and Hollister areas, with some employees traveling to/from San Jose.

VMT Calculation
In order to calculate VMT, the ADTs for Project and truck trips were multiplied by the assumed average trip length. As shown in Table 3.13-3, the daily VMT per employee would be 18 miles.

Total daily non-employee VMT would be 10,716 miles. It should be noted that by providing a source of aggregate near U.S. 101 and SR 25, the Project could generate fewer VMT than a similar project located in a remote area. Similarly, the Project could offset existing and/or future VMT generated by aggregate sources located farther from Santa Clara County communities. To provide a conservative analysis, this EIR did not assume these VMT reductions would occur.

3.13.4.2 Significance Criteria
Consistent with CEQA Guidelines Appendix G, the Project would result in a significant impact on transportation if it would:
a) Conflict with a program, plan, ordinance or policy addressing the circulation system, including transit, roadway, bicycle and pedestrian facilities; b) Conflict or be inconsistent with CEQA Guidelines Section 15064.3(b); c) Substantially increases hazards due to a geometric design feature (such as sharp curves or dangerous intersections) or incompatible uses (e.g., farm equipment); or d) Result in inadequate emergency access.

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-9 ESA / D201901577.01
Draft EIR July 2022
TABLE 3.13-3

VEHICLE MILES TRAVELED
Destination % of Trips
Number of Trips
(inbound and
outbound combined)
Average Trip
Length (miles) Daily VMT
Heavy Truck Trips
Santa Clara County 80 236 40 9,440
San Benito County 10 29 17 493
Monterey County 10 29 27 783
Total Truck Trips 100 294 36.45 10,716
Employees
100 30 18 540
Per Capita Employee VMT 18
NOTE: Since the 2017 TIA was prepared, the estimated number of trips associated with sales has been reduced slightly (from 300 trips per day to 278 trips per day). Therefore, total trips shown in this table and the resulting VMT calculation are slightly lower reported in the TIA (Appendix K).

SOURCE: Freeman Associates 2021b; Appendix K.1.

VMT Threshold
With respect to Significance Criterion (b), the VTA VMT estimator tool shows that the per capita daily VMT for employee trips in rural unincorporated Santa Clara County is 31.6 (WSP 2021).

This per capita VMT metric is used as the baseline for evaluating the Project’s employee trips.

The County has selected as the threshold a 15 percent reduction below this baseline, which would be 26.9 VMT per capita. This threshold is used for both direct and cumulative analyses. As discussed in the Governor’s Office of Planning and Research (OPR) Technical Advisory, “A project that falls below an efficiency-based threshold that is aligned with long-term environmental goals and relevant plans would have no cumulative impact distinct from the project impact.

Accordingly, a finding of a less-than-significant project impact would imply a less than significant cumulative impact, and vice versa.” (OPR 2018)
The VMT threshold guidance in OPR’s Technical Advisory was based on the California Air Resources Board 2017 Scoping Plan-Identified VMT Reductions and Relationship to State Climate Goals (OPR 2018). Consistent with that guidance, one of the thresholds for projectgenerated VMT is whether the project would result in a VMT per employee that is 15 percent below the baseline VMT per employee. Employee trips are only a small percentage of total Project vehicle trips; most trips would be heavy trucks used to haul aggregate to customers, as well as delivery and maintenance vehicles. There currently are no available models for analyzing truck trip VMT for projects such as the proposed Project, and no numerical threshold has been identified for heavy truck VMT. Therefore, this EIR conservatively uses as a significance threshold any increase in VMT resulting from additional truck trips.

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-10 ESA / D201901577.01
Draft EIR July 2022

3.13.4.3 Project Impacts
Impact 3.13-1: The Project would not conflict with County of Santa Clara policies addressing the circulation system, including transit, roadway, bicycle, and pedestrian facilities. (Less than Significant)
This impact discussion addresses Significance Criterion (a).

As described above in Section 3.13.2.4, the County General Plan includes policies that encourage access to new quarry sites to avoid impacts on local-serving routes and encourage alternatives to truck traffic, and require that new development ensure that road safety hazards or roadway deterioration is not significant. The Project would not conflict with these or any other County policies for the reasons described below.

Transit, Bicycle, and Pedestrian Facilities. There are no dedicated pedestrian or bicycle facilities in the immediate vicinity of the Project site or along the surrounding roadways. Due to the rural nature of the vicinity of the Project site, bicycle traffic is limited. The Project is not located along an existing bus route and no bus stops exist on the roadways likely to be used during construction and operation. Therefore, the Project would have no impact on these facilities.

Construction
All Project Components
Construction traffic would travel on major thoroughfares, including U.S. 101 and SR 25, to access the Project site, consistent with General Plan Policy R-RC 78. The only rural roadway that would provide access is Old Monterey Road, which is the only direct access to the Project site.

This local roadway serves a very limited area, so construction traffic would not substantially affect circulation in the area. As discussed in Chapter 2, Project Description, the portion of Old Monterey Road under County jurisdiction would be upgraded with additional paving and shoulders and maintained during the life of the Project, consistent with Policies R-RC 78 and R-TR 11. Project construction would not require new roadway construction or expansion of existing County roadways (beyond adding shoulders to existing Old Monterey Road), so Policy R-TR 14, requiring that the environmental effects of roadway construction and expansion be mitigated, would not apply. The impacts of providing improved access to U.S. 101 are addressed throughout this EIR. For these reasons, construction activities would not conflict with County transportation policies, and the impact would be less than significant.

For a discussion of temporary roadway hazards on U.S. 101 during construction, and how these are mitigated to less-than-significant levels, please see Impact 3.13-3.

Operation
Mining Pits and Processing Plant
The proposed processing plant and mining pits would be the primary generators of traffic because employees would work at both components, and deliveries and sales would occur at the processing

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-11 ESA / D201901577.01
Draft EIR July 2022
plant. Project employees and customers would use U.S. 101 and SR 25 to access the Project site.

These are both major thoroughfares that are designed to carry heavy truck traffic and are maintained by Caltrans. The portion of Old Monterey Road that is in the County would be paved and shoulders would be added, and it would be maintained during Project operation, so there would not be adverse effects on local-serving routes. In addition, the Project includes the use of trains to transport a portion of the aggregate to customers. For these reasons, Project operation would be consistent with General Plan Policy R-RC 78.

Project operation would not require new or expanded County roadways, so no new safety hazards would be created. The local County road that provides access to the Project site, Old Monterey Road, would be maintained during Project operation. For these reasons, Project operation would be consistent with Policies R-TR 9 and R-TR 11, and the impact would be less than significant.

Conveyor Belts and Access Roads
The conveyor belts and internal access routes would convey aggregate and Project traffic within the Project site only and would not affect local or regional roadways. Therefore, there would be no impact.

Rail Spur
The rail spur would provide a connection to the existing rail line, allowing for up to 28 percent of Project aggregate to be conveyed by rail rather than truck. This would support General Plan Policy R-RC-78, which encourages the use of non-vehicular transportation for aggregate.

Therefore, the impact would be less than significant.

Reclamation
As discussed in Section 2.4.6 of the Project Description, reclamation activities would occur for approximately 5 years after completion of each phase, and up to 5 years after completion of all mining. However, reclamation activities would not occur on a daily basis over these 5-year periods. Initially, reclamation of each phase would involve grading that would be conducted by the 15 Project employees. Similarly, removal of Project facilities, such as the processing plant, would be done by those Project employees. As discussed under Mining and Processing Plant, access to the Project site for employees would not entail the construction of new roadways or expansion of existing roadways. The small number of trips by reclamation employees would not result in the deterioration of roadways, and Old Monterey Road would be maintained through the life for the Project. For these reasons, reclamation activities would be consistent with General Plan transportation policies, and the impact would be less than significant.

Other reclamation activities, such as hydroseeding, tree planting, and monitoring, would be done by consultants under contract to the Applicant. Hydroseeding is estimated to employ approximately two employees or contractors for four days for each phase. Tree planting would employ approximately two employees or contractors for 21 days. Monitoring would be an intermittent activity occurring over the 5-year periods and would require approximately two consultants for up to two days per year. The addition of four trips (one in and one out for each reclamation employee) would occur only sporadically and would not be substantial enough to

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-12 ESA / D201901577.01
Draft EIR July 2022
create a hazard or result in roadway deterioration, even when added to the processing plant and mining trips. Therefore, the impact of reclamation traffic would be less than significant.

Summary
The Project would not affect transit or pedestrian or bicycle circulation or facilities, Access to the site would be provided via U.S. 101 and Old Monterey Road. Improvements would be designed and implemented according to Caltrans and County of Santa Clara standards for safety and emergency access; therefore, the project would not conflict with General Plan policies with regard to access and safety. The portion of Old Monterey Road that is in the County would be improved and maintained. A portion of Project aggregate would be transported by train, an alternative to truck transport. For these and other reasons described above, the Project would be consistent with General Plan transportation policies, and this impact would be less than significant.

Mitigation: None required.

Significance: Less than significant
_________________________
Impact 3.13-2: The Project would generate substantial additional VMT. (Significant and Unavoidable)
This impact addresses Significance Criterion (b).

Construction
All Project Components
CEQA Guidelines Section 15064.3(b)(3) refers to the use of qualitative analysis of constructionrelated VMT. As shown in Table 3.13-2, construction of all Project components (i.e., mining pits, processing plant, conveyor belts, rail spur, access roads, and roadway improvements) would generate a maximum of 60 worker trips per day (30 inbound trips 30 outbound trips) and 50 truck trips, for a total of 110 trips. This maximum number of trips would occur only during the 2-week overlap of construction of the Monterey Road and Northbound 101 on-ramp acceleration lane improvements. For the remainder of the 6-month construction period, the Project would generate a total of 18 to 40 trips per day.

For the most part, existing traffic would continue to operate normally during Project construction.

One lane on U.S. 101 could be closed for 2 to 4 days during improvement of the acceleration lane. Traffic could also be slowed at times when over-sized equipment (such as the processing plant) is brought to the Project site. The temporary closure of one lane and short periods when traffic is slowed for a short time would not result in the need to reroute traffic or detours, so the VMT for existing traffic should be unchanged.

Because the construction period would be short and would not involve large construction crews, and because existing traffic would not be rerouted to accommodate the Project, the impact related to construction VMT would be less than significant.

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-13 ESA / D201901577.01
Draft EIR July 2022
Operation and Reclamation
Employee VMT
As shown in Table 3.13-2, operation of all Project components (i.e., mining pits, processing plant, conveyor belts, rail spur, access roads, and reclamation) would generate a maximum of 30 worker trips per day (15 inbound trips and 15 outbound trips). Reclamation would periodically add another 4 trips (2 inbound and 2 outbound). As shown in Table 3.13-3, average employee trips would be approximately 18 miles long, which is below the County’s per capita VMT threshold of

26.9. Therefore, employee VMT would be less than significant.

Truck VMT
As shown in Table 3.13-2, the majority of Project-related vehicle trips would be sales-related, essentially distribution of aggregate products to customers. As shown in Table 3.13-3, the heavy truck trips would generate approximately 10,716 VMT daily.

As discussed above, Section 15064.3 of the CEQA Guidelines does not address heavy truck trips, and there is no other established threshold for evaluating VMT impacts from heavy truck trips for projects such as the proposed Project. However, given that very few trips originate from the Project site at present, and that the Project would increase VMT on regional roadways, the increase in truck-based VMT from the Project is considered a significant impact.

The Project provides for transport of some aggregate by rail. Up to 28 percent of aggregate exported from the Project site would be transported by rail. If the Project did not include this rail component, the Project VMT would be substantially higher. In addition, by providing an additional source of aggregate in south Santa Clara County, the Project could offset haul-truck related VMT in the County for those customers that would otherwise obtain aggregate from sources located farther away; however, to provide a conservative analysis this EIR did not assume such VMT reductions.

Summary
Daily employee VMT would be 18 miles per capita, which is well below the threshold of

26.9 VMT per capita. For heavy truck traffic, any increase is considered significant, and the Project would generate 10,716 VMT daily. Therefore, the increase in VMT is considered a significant impact.

Mitigation Measures: None available.

The Project VMT is driven largely by the location of the Project site and the dispersed nature of deliveries. The Project site is located in a rural area because that is where the aggregate is located. In addition, it is typical to locate such facilities in rural areas due to the potential incompatibility with denser residential and commercial uses located in more urban settings due to noise, heavy truck traffic on local roads, and the industrial nature of aggregate processing. Most of the Project VMT would be generated by new on-road truck trips (for delivery of materials to the Project and delivery of aggregate to customers). The Project already includes delivery of aggregate by rail up to 3 times per week. No additional feasible transportation options are available to replace or reduce these haul

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-14 ESA / D201901577.01
Draft EIR July 2022
truck trips. Therefore, no feasible mitigation is available to reduce the significant impact of truck-based VMT.

Significance: Significant and Unavoidable
_________________________
Impact 3.13-3: Project construction could increase roadway hazards due to the presence of large construction trucks, temporary lane closures, and detours. (Less than Significant with Mitigation Incorporated)
This impact discussion addresses Significance Criterion (c).

Construction
All Project Components
The primary impacts from the movement of construction trucks would include short-term and intermittent lessening of roadway capacities due to slower movements and larger turning radii of the trucks compared to passenger vehicles. In addition, drivers could experience delays if they were traveling behind a construction truck. Furthermore, Project construction activities would include improvements to public roadways (U.S. 101 on-ramp east of Sargent Ranch and Old Monterey Road) to facilitate truck access, as described in detail in Section 2.4 of the Project Description. According to the Applicant, the only lane closure on U.S. 101 would occur during the proposed improvements to the northbound U.S. 101 acceleration lane at the north/south roadway (Old Monterey Road Extension) on-ramp, just north of Tar Creek. The right lane could be closed for 2 to 4 days (Freeman Associates 2021c). During this time period, the northbound U.S. 101 shoulder lane at the on-ramp would be closed for protection of the construction crew with the use of cones, arrow board, and the appropriate advance warning signs as required by Caltrans (Freeman Associates 2021c).

Additionally, transportation of some of the plant equipment may require oversize load vehicles.

This equipment would be transported to the site following Caltrans and California Highway Patrol guidelines and standards, including flagging, signage, and pilot cars (Freeman Associates 2021c). Oversize load vehicles on state roadways require a transportation permit issued by Caltrans.

As with any work that encroaches onto the state right-of-way, the Project would be required to obtain an encroachment permit issued by Caltrans for the northbound on-ramp improvements.

Temporary traffic controls, such as road closure signs, would have to comply with the Traffic Control Manual. In addition, if Caltrans determines that traffic restrictions due to Project construction or proposed improvements may affect state highways, a Transportation Management Plan (TMP) may be required to be submitted to and approved by Caltrans prior to the initiation of construction. At this time, it is not known if a TMP would be required by Caltrans, or what the contents of the TMP strategies would be.

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-15 ESA / D201901577.01
Draft EIR July 2022
Lane closures and/or detours could introduce new or changed travel patterns, which, along with the movement of oversized vehicles, could temporarily result in new or increased roadway hazards. Therefore, construction traffic impacts would be significant.

Operation and Reclamation
Mining Pits, Conveyor Belt, Processing Plant, Rail Spur, Access Road and Reclamation
These Project components would be located entirely on-site and therefore would not create any hazards on public roadways or conflict with traffic on public roads. There would be no impact.

Roadway Improvements
Existing roadways (U.S. 101 and Old Monterey Road) would be used to access the Project site.

The existing acceleration lane on the northbound U.S. 101 on-ramp and public right-of-way portions of Old Monterey Road would be improved to Caltrans and County of Santa Clara engineering standards. The northbound acceleration lane would be 12 feet wide and 0.25 mile long, which would provide adequate line of sight (and correct an existing line of sight deficiency) and acceleration distance (Appendix K.1, pp. 7 and 8). No sharp curves or dangerous roadway conditions are proposed in public or private portions of the Project site and adherence to engineering standards would ensure the roadways meet a minimum standard of safety. The estimated 324 daily trips associated with the Project would be spread out through the course of the day and would not result in vehicle queues on the U.S. 101 off-ramps leading to the Project site that could not be accommodated by existing storage capacity (Appendix K.1, p. 41). For these reasons, Project roadway improvements would not create safety hazards, and the impact would be less than significant.

Summary
Project operation and reclamation would not create or contribute to safety hazards on roadways used to access the Project site. However, construction activities on the U.S. 101 northbound ramp could create temporary safety hazards, which would be a significant impact.

Mitigation Measure 3.13-3: Construction Traffic Control Plan The Applicant shall require the construction contractor to prepare and submit a Construction Traffic Control Plan to the County of Santa Clara Department of Public Works and Caltrans District 4 for approval prior to the onset of construction. The Construction Traffic Control Plan shall be prepared in accordance with the California Department of Transportation Transportation Management Plan Guidelines (2015) and shall include, at a minimum, the following:
a. Restricting or limiting heavy vehicle traffic to and from the Project site to occur outside the peak commute hours (7:00-9:00 a.m. and 4:00-6:00 p.m.); b. Timing of deliveries of heavy equipment and building materials to occur outside the peak commute hours;
c. Directing construction traffic with a flag person;

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-16 ESA / D201901577.01
Draft EIR July 2022
d. Placing temporary signage, lighting, and traffic control devices if required, including, but not limited to, appropriate signage along access routes to indicate the presence of heavy vehicles and construction traffic;
e. Ensuring access for emergency vehicles to the Project site; f. Temporarily closing travel lanes or delaying traffic during materials delivery or the construction of roadway improvements;
g. Storing construction equipment on-site during construction; h. Identifying and using truck routes acceptable to Caltrans and the County for construction-related heavy trucks;
i. Maintaining access to any adjacent properties; and,
j. Specifying both construction-related vehicle travel and oversize load haul routes, minimizing construction traffic during the a.m. and p.m. peak hours.

Significance after Mitigation: Less than significant
The implementation of Mitigation Measure 3.13-3 would minimize motorist delay and would ensure that motorists can travel safely through Project work zones, thereby reducing this impact to a less-than-significant level.
_________________________
Impact 3.13-4: The Project could result in inadequate emergency access. (Less than Significant with Mitigation Incorporated)
Construction
All Project Components
As discussed in Impact 3.13-3, Project construction could require temporary lane closures, which could affect the movement of emergency vehicles. This would be a significant impact.

Operation and Reclamation
Mining Pits, Conveyor Belt, Processing Plant, Rail Spur, and Reclamation These Project components would be located entirely would not affect emergency vehicle circulation on public roads. Emergency vehicles could use on-site access roads to move around the Project site, if necessary. Therefore, the impact would be less than significant.

Roadway Improvements
The Project site is located in an undeveloped rural area of Santa Clara County with the primary access roads (Old Monterey Road, Old Monterey Road Extension) allowing adequate emergency egress and ingress to the site. Therefore, the development of the Project would not physically interfere with emergency vehicle access or personnel evacuation from the site.

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-17 ESA / D201901577.01
Draft EIR July 2022
As described above, increased Project-related traffic would not cause a significant increase in congestion and/or significantly worsen the existing operating conditions on area roads; therefore, Project-related traffic would not affect emergency access to the Project site or any other surrounding location. The Project would not require closures of public roads, which could inhibit access by emergency vehicles. For these reasons, construction and operation of roadway improvements would have a less-than-significant impact on emergency access.

Summary
Construction activities could temporarily impede the movement of emergency vehicles when work is being conducted on U.S. 101 and/or Old Monterey Road, which would be a significant impact. Once construction on these roadways is complete, the Project would no longer interfere with or adversely affect emergency vehicles, so the operational and reclamation impacts would be less than significant.

Mitigation Measure 3.13-4: Implement Mitigation Measure 3.13-3, Construction Traffic Control Plan.

Significance after Mitigation: Less than significant
The implementation of Mitigation Measure 3.13-3 requires that the Construction Traffic Control Plan include provisions to maintain emergency access, which would ensure that emergency vehicles could travel through U.S. 101 and Monterey Road during Project construction, thereby reducing this impact to less-than-significant levels. _________________________

3.13.4.4 Cumulative Analysis
The analysis of consistency with applicable transportation plans and policies (Impact 3.13-1) is project-specific, because it is not affected by other projects in the region. Therefore, there would not be a cumulative impact regarding policy and plan consistency.

Impact 3.13-5: The Project would contribute to cumulative increases in vehicle miles traveled. (Significant and Unavoidable)
The region, like much of the state, already experiences significant VMT. Although the state has enacted laws aimed at encouraging transit-oriented and infill land use planning and development, other growth will continue to occur in suburban and rural areas, such as unincorporated Santa Clara County, that require relatively lengthy trips due to the distance between residential development and employment centers. While there are a variety of measures available to residential and commercial development to reduce VMT, such as mixed-use land use patterns and transit programs, these approaches are not typically available for industrial projects, particularly those such as aggregate mining and processing that must be located in rural areas. Because the extent to which future projects will be able to achieve VMT reductions is unknown at this time, cumulative VMT impacts are assumed to be significant.

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-18 ESA / D201901577.01
Draft EIR July 2022
As discussed above, the increase in VMT associated with Project employees would be below the County’s threshold. However, heavy trucks transporting aggregate from the Project site to customers, and materials from vendors to the Project site would generate 10,716 daily VMT. To the extent that Project trips displace aggregate deliveries from other sources at greater distances, the net increase in Project VMT may be lower than 10,716.,although the EIR does not assume this. However, the Project would generate new trips so there would be an increase in VMT, which could inhibit the County and the state from achieving reductions in regional and statewide VMT.

The Project would contribute to a significant cumulative VMT impact, and its contribution would be cumulatively considerable pre-mitigation. No feasible mitigation is available to reduce the VMT impacts of the Project to less-than-cumulatively considerable. This impact would therefore be significant and unavoidable.

Mitigation Measure: None available.

As discussed in Impact 3.13-2, no transportation options are available to replace or reduce haul truck trips. Therefore, no feasible mitigation is available to reduce the significant impact of truck-based VMT.

Significance after Mitigation: Significant and Unavoidable _________________________
Impact 3.13-6: The Project would contribute to significant cumulative increases in roadway hazards and/or interference with emergency access. (Less than Significant with Mitigation Incorporated)
For purposes of the analysis, the geographic scope for cumulative impacts on roadway safety and emergency access is focused on projects located within six miles of the Project that are currently under construction, planned, or approved, because projects within 6 miles of the Project are the only ones likely to contribute traffic to the study area roadways, if constructed or operated concurrently.

Of the five cumulative projects identified in Table 3.1-1 located within 6 miles of the Project site, three are minor zoning, modification, or redevelopment actions that would not contribute substantial traffic to regional roadways that would be used by Project traffic. Two cumulative projects, the U.S. 101 Widening and the Christopher Ranch Farm Worker Housing Project, would use the same roads as Project construction and operation traffic.

U.S. 101 Widening Project
The U.S. 101 Widening project, identified as VTP ID #H25 in the VTP 2040, would expand U.S. 101 from four to six lanes between Gilroy and SR 129 in San Benito County; reconstruct the U.S. 101/SR 25 interchange, extend Santa Teresa Boulevard from Castro Valley Road to the U.S. 101/SR 25 interchange; improve the southbound U.S. 101 off-ramp at SR 129, grade-separate the Union Pacific Rail crossing on SR 25 west of Bloomfield Avenue, and construct new bicycle facilities.

Phase I of the project, which includes widening of the SR 25 bridge over U.S. 101, extending the length of the southbound U.S. 101 off-ramp to SR 25, upgrades to the northbound U.S. 101 ramps

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-19 ESA / D201901577.01
Draft EIR July 2022
at SR 25 to improve exit and merging operations, and new traffic signals at the ramp intersections, is fully funded with construction currently anticipated to occur between 2023 and 2025. As additional funding becomes available, future phases of interchange improvements would be scheduled. (VTA 2020).

Future phases of the U.S. 101 Widening Project also would include the construction or improvement of various frontage roads along both side of U.S. 101, including Old Monterey Road, and the elimination of uncontrolled local and private access to/from U.S. 101, including the existing U.S. 101 southbound ramps at Old Monterey Road.

Christopher Ranch Farm Worker Housing Project - Gilroy
This project, identified by the County of Santa Clara as PLN19-0215, would construct housing to accommodate agricultural workers near Gilroy, approximately 4 miles north of the Project site.

The Christopher Ranch project would renovate six existing buildings to provide housing for 160 to 200 seasonal skilled agricultural workers in 38 units. The project would provide transportation for workers, so only 11 standard parking spaces and five bus spaces would be provided (Christopher Ranch, LLC 2020).

The status and estimated schedule for the Christopher Ranch project are currently unknown, so it is assumed that traffic generated by construction and operation of this agricultural housing project could overlap with construction and/or operation of the Project and would use some of the same roadways that would be used by vehicles traveling to/from the Project site, namely U.S. 101 and SR 25.

This Christopher Ranch project does not propose any improvements along U.S. 101 or SR 25, so it is unlikely to require road closures or detours, or otherwise result in increased hazards and/or deterioration of roadway conditions on U.S. 101 and SR 25.

Summary
Both construction and operational traffic from the U.S. Widening Project and the Christopher Ranch housing project would use roads that would also be used by the Sargent Quarry project.

The U.S. 101 Widening Project construction would occur within U.S. 101 and SR 25, which could require lane closures, detours and other disruptions, resulting in deteriorating conditions and/or safety hazards on these roadways. If closures, delays and/or detours do occur, emergency access in the region could be adversely affected. The Phase I improvements of the U.S. 101 Widening Project are mainly intended to improve connectivity, traffic operations, and safety conditions at the U.S. 101/SR 25 interchange; such improvements would not generate new vehicle trips on study area roadways and would improve traffic conditions once construction is complete. The Christopher Ranch housing project would not require construction on U.S. 101 or SR 25, but construction traffic could use these roadways. After it is constructed, vehicle trips associated with the housing project would be too minimal to affect roadway hazardous conditions, because project traffic would be limited. For these reasons, cumulative impacts related to roadway hazards and emergency access would be significant, but this impact would be temporary, occurring only during construction of each project.

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-20 ESA / D201901577.01
Draft EIR July 2022
Project Contribution
As discussed in Impacts 3.13-3 and 3.13-4, Project construction activities could result in roadway hazards and interference with emergency access due to lane closures and transport of oversized loads. If these activities occurred during construction of the U.S. 101 Widening project and/or the Christopher Ranch housing project, the potential for hazards and interference with emergency vehicles would be increased. This would be a considerable contribution to the temporary risk of roadway hazards and interference with emergency vehicles, so the Project’s contribution to the cumulative roadway hazards and emergency access impact during construction would be cumulatively considerable, and therefore significant.

Project construction would be complete within nine months. After completion of construction, the Project would no longer contribute to cumulative risks of roadway hazards or emergency access, because the Project would not require lane closures or transport of oversized equipment. Further, operational Project traffic would not alter roadway conditions to the extent that hazardous conditions would be created and/or that would interfere with emergency vehicles. Further, as shown in Table 3.13-4, Existing with Project Operation Traffic Volumes, after construction the Project would contribute very little traffic to those regional transportation facilities (i.e., no more than 1.1 percent of overall traffic). The TIA (Appendix K.1) concluded that the Project trips that would be rerouted as a result of the removal of the U.S. 101 southbound ramps at Old Monterey Road and that the connection of Old Monterey Road with the newly constructed U.S. 101/SR 25 interchange would ensure that any queues at the newly constructed ramps could accommodated by future planned storage capacity.

Mitigation Measure 3.13-6: Implement Mitigation Measure 3.13-3, Construction Traffic Control Plan.

Significance after Mitigation: Less than significant
Mitigation Measure 3.13-3 requires that the Construction Traffic Control Plan include provisions to ensure that motorists can travel safely through Project work zones and to maintain emergency access, which would ensure that roadway hazards would be minimized, and emergency vehicles could travel through U.S. 101 and Old Monterey Road during Project construction, thereby reducing the Project contribution to this cumulative impact to a less-than-cumulatively considerable and less-than-significant level. _________________________

3.13.5 References
California Department of Motor Vehicles (CDMV), 2019-2021. California Commercial Drive Handbook, English, 2019-2021.

California Department of Transportation (Caltrans) 2014. Manual on Uniform Traffic Control Devices. Available online at: https://dot.ca.gov/programs/safety-programs/camutcd.

Accessed August 30, 2021.

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-21 ESA / D201901577.01
Draft EIR July 2022
California Department of Transportation (Caltrans) 2015. Transportation Management Plan Guidelines. November 2021.

California Department of Transportation (Caltrans) 2019a. Highway Design Manual, 2019.

Available at https://dot.ca.gov/programs/design/manual-highway-design-manual-hdm.

California Department of Transportation (Caltrans) 2019b. 2019 Traffic Volumes on California State Highways. Available online at: https://dot.ca.gov/programs/traffic-operations/census.

Accessed February 26, 2021.

Christopher Ranch, LLC 2019. 935 Southside Drive, Santa Clara County (Assessor Parcel Number 841-15-005) Project Description for Use Permit and Architecture and Site Approval (ASA), Record Number PLN18-112235, December 11, 2019.

County of Santa Clara, 2020. Implementation of County Thresholds and Procedures for Evaluating Vehicle Miles Travelled (VMT) in California Environmental Quality Act Documents. https://eservices.sccgov.org/OffAgenda/Home/ViewFile/424. Accessed on February 26, 2021.

Federal Railroad Administration 2009. Final Report, Comparative Evaluation of Rail and Truck Fuel Efficiency on Competitive Corridors. November 19, 2009. Available at https://railroads.dot.gov/sites/fra.dot.gov/files/fra_net/2925/Comparative_Evaluation_Rail_ Truck_Fuel_Efficiency.pdf.

Freeman Associates 2021a. SQ Summary of Recent Project Information, attachment to electronic communication from Verne Freeman to David Rader, Senior Planner, County of Santa Clara, April 20, 2021.

Freeman Associates 2021b. Electronic communication from Verne Freeman to David Rader, Senior Planner, County of Santa Clara, November 19, 2021.

Freeman Associates 2021c. Electronic communication from Verne Freeman to David Rader, Senior Planner, County of Santa Clara, February 23, 2021.

Governor’s Office of Planning and Research (OPR) 2018. Technical Advisory on Evaluating Transportation Impacts in CEQA. Available online at: https://www.opr.ca.gov/ docs/20190122-743_Technical_Advisory.pdf. Accessed February 26, 2021.

Valley Transportation Authority (VTA) 2015. VTP2040: The Long-Range Transportation Plan for Santa Clara County. Available online at: http://vtaorgcontent.s3-us-west1.amazonaws.com/Site_Content/VTP2040_final_hi%20res_030315.pdf. Accessed February 26, 2021.

Valley Transportation Authority (VTA) 2020. Fact Sheet: US 101/SR 25 Interchange – Phase 1.

Available online at: https://www.vta.org/sites/default/files/2020-12/Fact%20Sheet %20%28English%29_1.pdf. Accessed February 26, 2021.

WSP 2021. A Framework for Implementing SB-743 in Unincorporated Santa Clara County, April 6, 2021.

3. Environmental Setting, Impacts, and Mitigation Measures

3.13 Transportation
Sargent Quarry 3.13-22 ESA / D201901577.01
Draft EIR July 2022
This page intentionally left blank

3. Environmental Setting, Impacts, and Mitigation Measures

3.14 Utilities and Service Systems
Sargent Quarry 3.14-1 ESA / D201901577.01
Draft EIR July 2022

3.14 Utilities and Service Systems

3.14.1 Introduction
Project impacts on utilities and service systems, specifically water supply and solid waste disposal, are discussed in this section. Because the project would use an on-site septic system rather than connecting to a sewer system, there would be no impact on municipal wastewater treatment infrastructure, and this topic is not discussed further. Similarly, the Project site is not connected to municipal or County storm drains, so this issue is not addressed in this section.

Impacts due to installation of a new groundwater well and reconfiguring onsite drainages and related issues are addressed in Section 3.10, Hydrology and Water Quality. Analysis of energy utilities and service systems (e.g., gas, electricity) is provided in Section 3.6, Energy.

3.14.2 Regulatory Setting

3.14.2.1 Federal
Federal Safe Drinking Water Act
The U.S. Environmental Protection Agency (USEPA) administers the Safe Drinking Water Act (SDWA), the primary federal law that regulates the quality of drinking water and establishes standards to protect public health and safety. The State Water Resources Control Board (SWRCB) implements the SDWA and oversees public water system quality statewide. SWRCB establishes legal drinking water standards for contaminants that could threaten public health.

3.14.2.2 State
California Urban Water Management Planning Act – Water Supply Planning The 1983 California Urban Water Management Planning Act (Water Code Section 10610-10656, as amended) requires every urban water supplier to prepare and adopt an Urban Water Management Plan (UWMP) and update it every five years. The UWMP must describe demographic factors affecting water management planning (such as projected population changes), describe and quantify (if possible) existing and planned sources of water available to the supplier in five-year increments to 20 years or as far as data are available, and describe the reliability and vulnerability of the water supply. The UWMP must include all water supply projects and programs that may be undertaken by the urban water supplier to meet the total projected water demand. The Santa Clara Valley Water District (now known as Valley Water), an independent special district that serves all of Santa Clara County including the Project area, meets the definition of an urban water supplier, and its most recent UWMP is described below in Section 3.14.2.3.

Senate Bill 610 - Water Supply Assessments
Senate Bill 610, codified in California Water Code section 10910 et seq., requires preparation of a water supply assessment for projects as defined in Water Code section 10912. Proposed industrial, manufacturing, processing plants, or industrial parks planned to house more than 1,000 persons, occupy more than 40 acres of land, or having more than 650,000 square feet of floor area are

3. Environmental Setting, Impacts, and Mitigation Measures

3.14 Utilities and Service Systems
Sargent Quarry 3.14-2 ESA / D201901577.01
Draft EIR July 2022
required to prepare a water supply assessment pursuant to this code. If a water supply for a proposed project includes groundwater, the water supply assessment must include a review of any information contained in the urban water management plan relevant to the identified water supply for the project, a description of any groundwater basin or basins from which the project would be supplied, information about whether the basin is overdrafted, and an analysis of the sufficiency of the groundwater basin or basins to meet the projected water demand associated with the project, among other information. The water supply assessment must also include discussion of how supply will meet demand during normal, single dry, and multiple dry years during a 20-year projection. A water supply assessment has been prepared for this Project and is discussed in Section 3.14.4.3, Project Impacts; see Appendix I.3.

California Safe Drinking Water Quality Act
The California Safe Drinking Water Act strengthens the federal Safe Drinking Water Act by authorizing the State to protect the public from contaminants in drinking water by establishing maximum contaminants levels (MCLs) that are at least as stringent as those developed by the USEPA.

California Integrated Waste Management Act of 1989
The California Integrated Waste Management Act of 1989 (Public Resources Code Section 40000-49620) established the Integrated Waste Management Board (now known as CalRecycle), required the implementation of integrated waste management plans, and mandated that local jurisdictions divert at least 75 percent of solid waste generated (from 1990 levels) by 2010. Local jurisdictions each have a per resident and per employee disposal rate target, expressed in pounds per person per day (PPD). For unincorporated Santa Clara County, these targets are four PPD and

13.1 PPD, respectively (CalRecycle 2021a). Santa Clara County’s Integrated Waste Management Plan is described below in Section 3.14.2.3.

Assembly Bill 341
AB 341 set forth requirements of the statewide mandatory commercial recycling program in the Public Resources Code that are applicable to the Project’s operations. Businesses that generate four or more cubic yards of garbage per week are required to recycle (Public Resources Code Section 42649-42649.7).1
Surface Mining and Reclamation Act (SMARA)
SMARA regulations require the preparation of a detailed reclamation plan, which must follow the following standards related to waste management:
• All buildings, structures, and equipment shall be dismantled and removed prior to final mine closure except those buildings, structures, and equipment approved in the reclamation plan as necessary for the end use.
1 “Businesses” are defined in this code as any commercial or public entity, including but not limited to a firm, partnership, proprietorship, joint-stock company, corporation, or association that is organized as a for-profit or nonprofit entity. “Commercial solid waste” includes all types of waste generated by such a business.

3. Environmental Setting, Impacts, and Mitigation Measures

3.14 Utilities and Service Systems
Sargent Quarry 3.14-3 ESA / D201901577.01
Draft EIR July 2022
• All equipment, supplies, and other materials shall be stored in designated areas (as shown in the approved reclamation plan). All waste shall be disposed of in accordance with state and local health and safety ordinances.

3.14.2.3 Local
Santa Clara County General Plan
The following Santa Clara County General Plan policies regarding water supply and solid waste management would apply to the project:

Policy C-RC 8: Environmental impacts of all state and local water supply planning and decision-making should be taken into full consideration.

Policy C-RC 12: More efficient use of water for agricultural irrigation and industrial processes should be promoted through improved technology and practices.

Policy C-RC 64: Countywide solid waste management efforts shall be guided by the hierarchy of strategies outlined below, emphasizing resource recovery in accordance with state law: a. Source reduction and reuse, b. Recycling and composting, c. Transformation, and d. Landfilling as final option.

Policy C-RC 65: All solid waste management services and facilities shall conform to applicable federal, state, and local regulations and standards.

County Garbage and Refuse Ordinances
Section B11-160 et seq. of the County Ordinance Code requires that all refuse generated from the unincorporated area be delivered to or disposed at a properly permitted disposal facility, transfer station, or other facility authorized by the County. No person may produce or store refuse of any kind in a manner that would represent a threat to the public or environmental health. In remote areas where curbside or collection station garbage service cannot be provided, the refuse producer may transport their own garbage to an approved solid waste facility with a frequency and mode of transport to preclude any nuisance conditions. It is unlawful for any person to throw away, deposit or bury, or cause to be thrown away, deposited or buried, any refuse, except at an approved disposal or collection area unless authorized by the County.

County of Santa Clara Integrated Waste Management Plan
The County of Santa Clara Integrated Waste Management Plan (1995) sets the overall waste diversion goals of the County and describes the programs to be implemented by each jurisdiction in the County to achieve these goals. The programs address source reduction, recycling, composting, special wastes, and public education. Programs and policies relevant to the Project include encouraging landfills and transfer stations to implement variable pricing that incentivizes waste stream separation (e.g., charging less to dispose of clean landscaping waste that can be composted). There are no Project-specific requirements in this plan, but the landfills and transfer stations that would handle Project-generated solid wastes would be subject to requirements in this plan.

3. Environmental Setting, Impacts, and Mitigation Measures

3.14 Utilities and Service Systems
Sargent Quarry 3.14-4 ESA / D201901577.01
Draft EIR July 2022
Valley Water Urban Water Management Plan
The Valley Water 2020 Urban Water Management Plan (Valley Water 2021a) provides information on water supply, water usage, recycled water, conservation programs, water shortage contingency planning, and water supply reliability in Santa Clara County and addresses the water supply future of the County through 2045. As part of the UWMP, Valley Water has developed a water shortage contingency plan to manage water supplies and demands during water shortages due to droughts and other emergencies. Valley Water also promotes water conservation through a range of demand management measures such as metering, public education and outreach, and rebates for residential and commercial users. (Valley Water 2021) Water Shortage Contingency Plan
Valley Water prepared the Water Shortage Contingency Plan (WSCP) to identify specific conditions that would trigger the need for reductions in demand due to drought conditions or an emergency that affects water supply (Valley Water 2021b). The WSCP identifies five stages and associated recommended short-term reductions in water use. For example, Stage 2, Alert, would occur if projected end-of-year groundwater storage drops to 250,000 to 300,000 acre feet, and would require reductions in water use of zero to 10 percent, while Stage 4, Critical, would occur if projected end-of-year groundwater storage dropped to 150,000 to 200,000 acre feet, requiring 20 to 40 percent reductions in water use. As a water wholesaler, Valley Water does not have direct authority over retail rates and does not employ staff to enforce water restrictions.

Therefore, Valley Water coordinates with the County, cities, water retailers, large landscapers and agricultural uses to implement applicable ordinances and water use restrictions.

3.14.3 Environmental Setting

3.14.3.1 Water Supply
Water service to the Project site is currently provided by an existing private well, as neither the County nor nearby cities have water services extending to the Project area. The well draws from the Llagas groundwater subbasin, managed by Valley Water, and is located just south of the proposed Project well that would be located adjacent to the processing plant. The next closest wells are east of U.S. 101 along the south bank of Tar Creek; Valley Water operates a monitoring well and Sun and Sons LP operates an irrigation well.

The Llagas subbasin, part of the larger Gilroy-Hollister Valley Groundwater Basin, covers a surface area of about 88 square miles bounded by the Santa Cruz Mountains to the west and the Diablo Range to the east. The subbasin’s southern boundary is based on the boundary between Santa Clara and San Benito counties rather than on groundwater conditions. Groundwater upwells in the southwestern corner of the Llagas subbasin, supporting wetland vegetation adjacent to a perennial reach of the Pajaro River. Groundwater upwelling in this area likely flows into the Pajaro River, which then flows west through the Santa Cruz Mountains to Monterey Bay.

Groundwater is the primary source of water supply for the Llagas subbasin. Regional groundwater pumping in the Llagas subbasin averaged 41,400 AFY between 2015 and 2019. During 2019, groundwater storage in Llagas subbasin increased by 6,900 AF (Valley Water 2020).

3. Environmental Setting, Impacts, and Mitigation Measures

3.14 Utilities and Service Systems
Sargent Quarry 3.14-5 ESA / D201901577.01
Draft EIR July 2022
About half of the County’s water supply comes from local sources and about half comes from imported water sources. Imported water includes State Water Project and Central Valley Project contract supplies and supplies delivered by the San Francisco Public Utilities Commission (Valley Water 2021a). Table 3.14-1 summarizes projected future water demand for the County and for the Llagas groundwater subbasin. While agricultural pumping, 85 percent of which occurs in the Llagas subbasin, is likely to remain stable through 2040, municipal use is projected to increase by almost 4 percent from 2025 to 2045. To meet projected increases in municipal use, Llagas subbasin withdrawal is projected to increase by 8 percent, or 6,000 acre-feet per year, from 2025 to 2040 (Appendix I.3).

TABLE 3.14-1

PROJECTED WATER DEMAND, SANTA CLARA COUNTY AND LLAGAS GROUNDWATER SUBBASIN Sector 2025 2030 2035 2040 2045
Countywide
Municipal Retailers 288,000 280,000 285,000 290,000 299,000 Agricultural Groundwater Pumping 25,000 25,000 25,000 25,000 25,000 Independent Groundwater Pumping 14,000 14,000 14,000 14,000 14,000 Raw Water 2,000 2,000 2,000 2,000 2,000
Losses 3,000 3,000 3,000 3,000 3,000
Countywide Demand Total 332,000 324,000 329,000 334,000 343,000 Llagas Subbasin
Llagas Groundwater Demand Total 49,000 52,000 53,000 53,000 n/a SOURCE: Valley Water 2021a, 2016.

In the 2020 UWMP, water supply estimates are provided for future single dry years and multiple dry year periods on a county wide basis. Table 3.14-2 shows the anticipated sources of water supply during a normal year. Table 3.14-3 shows the reductions in supply that are projected to occur during single-dry and multiple-dry year periods and compares projected supply and demand. The reductions in supply are mainly reductions in imported water (Appendix I.3). As shown in Table 3.14-3, supply is projected to exceed demand in every period. During the singledry year period, supply is estimated to be 80 percent of normal supply.

It should be noted that the imported water is used to meet supply in the Santa Clara Plain and is not expected to affect the supply in Llagas subbasin, which relies on groundwater and some recycled water. As experienced in the most recent drought, demands will likely be reduced further with water conservation. (Appendix I.3)
Valley Water is evaluating supply projects and programs to increase water supply with a goal of requiring conservation reductions no more than 10 percent. Additional projects and programs may include additional long-term water conservation savings, water recycling, recharge capacity, storm water capture and reuse, banking, and storage (Valley Water 2021a, 2021b).

3. Environmental Setting, Impacts, and Mitigation Measures

3.14 Utilities and Service Systems
Sargent Quarry 3.14-6 ESA / D201901577.01
Draft EIR July 2022
TABLE 3.14-2

PROJECTED SOURCES OF WATER SUPPLY, SANTA CLARA COUNTY AND LLAGAS GROUNDWATER SUBBASIN Sector 2025 2030 2035 2040 2045
Countywide Normal Year Supply
Groundwater 140,000 164,000 163,000 162,000 162,000
Local Surface Water 30,000 70,000 185,000 185,000 185,000 Recycled Water 16,000 19,000 22,000 26,000 28,000
Potable Reuse - - - - -
San Francisco Public Utilities Commission 55,000 26,000 59,000 61,000 63,000 Central Valley Project and State Water
Project Allocations 130,000 134,000 136,000 139,000 142,000 Countywide Normal Year Supply Total 446,000 518,000 640,000 643,000 650,000 Llagas Subbasin
Llagas Groundwater Supply Total 49,000 52,000 53,000 53,000 n/a SOURCE: Valley Water 2021a, 2016.

TABLE 3.14-3

COMPARISON OF PROJECTED COUNTYWIDE SUPPLY AND DEMAND UNDER NORMAL YEAR, SINGLE DRY YEAR,

AND MULTIPLE DRY YEAR CONDITIONS
2025 2030 2035 2040 2045
Normal Year
Available Supply (AFY) 446,000 518,000 640,000 643,000 650,000 Projected Demand (AFY) 330,000 325,000 330,000 335,000 345,000 Difference (AFY) 116,000 193,000 310,000 308,000 305,000 Single Dry Year
Available Supply (AFY) 355,000 373,000 497,000 503,000 505,000 Projected Demand (AFY) 330,000 325,000 330,000 335,000 345,000 Difference (AFY) 25,000 48,000 167,000 168,000 160,000
Single Dry Year Supply as % of Normal
Year Supply 80% 72% 78% 78% 78%
Multiple Dry Year
First Year
Available Supply (AFY) 345,000 349,000 491,000 483,000 487,000 Projected Demand (AFY) 330,000 325,000 330,000 335,000 345,000 Difference (AFY) 15,000 24,000 161,000 148,000 142,000
First Dry Year Supply as % of Normal
Year Supply 77% 67% 77% 75% 75%
Second Year
Available Supply (AFY) 370,000 376,000 477,000 482,000 501,000 Projected Demand (AFY) 330,000 325,000 330,000 335,000 345,000 Difference (AFY) 40,000 51,000 147,000 147,000 156,000
Second Dry Year Supply as % of Normal
Year Supply 83% 73% 75% 75% 77%

3. Environmental Setting, Impacts, and Mitigation Measures

3.14 Utilities and Service Systems
Sargent Quarry 3.14-7 ESA / D201901577.01
Draft EIR July 2022
TABLE 3.14-3 (CONTINUED)

COMPARISON OF PROJECTED COUNTYWIDE SUPPLY AND DEMAND UNDER NORMAL YEAR, SINGLE DRY YEAR,

AND MULTIPLE DRY YEAR CONDITIONS
2025 2030 2035 2040 2045
Multiple Dry Year (cont.)
Third Year
Available Supply (AFY) 340,000 349,000 443,000 450,000 448,000 Projected Demand (AFY) 330,000 325,000 330,000 335,000 345,000 Difference (AFY) 10,000 24,000 113,000 115,000 103,000
Third Dry Year Supply as % of Normal
Year Supply 76% 67% 69% 70% 69%
Fourth Year
Available Supply (AFY) 347,000 341,000 416,000 421,000 429,000 Projected Demand (AFY) 330,000 325,000 330,000 335,000 345,000 Difference (AFY) 17,000 16,000 86,000 86,000 84,000
Fourth Dry Year Supply as % of Normal
Year Supply 78% 66% 65% 65% 65%
Fifth Year
Available Supply (AFY) 341,000 365,000 430,000 440,000 444,000 Projected Demand (AFY) 330,000 325,000 330,000 335,000 345,000 Difference (AFY) 11,000 40,000 100,000 105,000 99,000
Fifth Dry Year Supply as % of Normal
Year Supply 76% 70% 67% 68% 68%
SOURCE: Valley Water 2021a, Tables 7-2, 7-3, and 7-4.

3.14.3.2 Solid Waste Disposal
Solid waste generated in unincorporated areas of Santa Clara County is sent to several different landfills. In 2019, unincorporated Santa Clara County generated just over 100,000 tons of waste, with 97 percent of it going to six specific landfills: John Smith Road landfill (56,142 tons), Kirby Canyon landfill (10,129 tons), Billy Wright Disposal Site (9,895 tons), Newby Island Sanitary landfill (8,422 tons), Monterey Peninsula Landfill (7,995 tons), and Guadalupe Sanitary Landfill (7,114 tons) (CalRecycle 2020). Of these, Kirby Canyon Landfill is most conveniently located to the Project site, at 25 miles north on U.S. 101. Kirby Canyon Landfill had a remaining capacity of approximately 16 million cubic yards in 2015 and a maximum permitted throughput of 2,600 tons per day. Based on current tonnage rates, it will remain open until 2059 (CalRecycle 2021b).

Additionally, Buena Vista Landfill, located in Santa Cruz County, is located 21 miles west of the Project site via SR 129 and has a remaining capacity of 2 million cubic yards and a maximum permitted throughput of 838 tons per day, and is estimated to close in 2031 (CalRecycle 2021c).

Reporting year 2015 is the most recent approved local jurisdiction report for the County’s Integrated Waste Management Plan, and results indicate that the county generated less waste per resident (3.0 PPD) and per employee (9.9 PPD) than the County-specific target disposal rates (4 and 13.1 PPD, respectively). The 2015 total adjusted reporting-year disposal amount for unincorporated Santa Clara County was 48,395 tons (CalRecycle 2016).

3. Environmental Setting, Impacts, and Mitigation Measures

3.14 Utilities and Service Systems
Sargent Quarry 3.14-8 ESA / D201901577.01
Draft EIR July 2022

3.14.4 Impact Evaluation

3.14.4.1 Approach to the Analysis
The section evaluates whether the Project would necessitate relocation or construction of new or expanded utility facilities such that significant environmental effects could result by reviewing available information about utilities serving the Project area and assessing whether impacts associated with relocation or construction of utilities would result in additional effects beyond those identified for the Project. This section also analyzes the potential for Project implementation to adversely affect water supply, attainment of solid waste reduction goals, and compliance with solid waste statutes and regulations. For water supply, the analysis relies on the water supply assessment (WSA) prepared for the Project to characterize whether supplies are sufficient to meet the water demand associated with Project operations. For attainment of solid waste reduction goals and compliance with statutes and regulations, the analysis considers whether Project construction, operation or reclamation would conflict with adopted goals, statutes, and regulations.

3.14.4.2 Significance Criteria
The Project would result in a significant impact on utilities and service systems if it would:
a) Require or result in the relocation or construction of new or expanded water, wastewater treatment or storm water drainage, electric power, natural gas, or telecommunications facilities, the construction or relocation of which could cause significant environmental effects;
b) Not have sufficient water supplies available to serve the project and reasonably foreseeable future development during normal, dry, and multiple dry years; c) Result in a determination by the wastewater treatment provider which serves or may serve the project that it has adequate capacity to serve the project’s projected demand in addition to the provider’s existing commitments;
d) Generate solid waste in excess of State or local standards, or in excess of the capacity of local infrastructure, or otherwise impair the attainment of solid waste reduction goals; or e) Not comply with federal, state, and local management and reduction statutes and regulations related to solid waste.

Analysis of energy utilities and service systems (e.g., gas, electricity) is provided in Section 3.6, Energy, of this Draft EIR.

Due to the nature of the Project, the following criteria are not analyzed in this section for the reasons described below:
a) Require or result in the relocation or construction of new or expanded water, wastewater treatment or storm water drainage, electric power, natural gas, or telecommunications facilities, the construction or relocation of which could cause significant environmental effects. As discussed in Section 3.14.1, Introduction, the Project would not connect to a municipal sewer or storm drain system, so these facilities would not need to be expanded to

3. Environmental Setting, Impacts, and Mitigation Measures

3.14 Utilities and Service Systems
Sargent Quarry 3.14-9 ESA / D201901577.01
Draft EIR July 2022
serve the Project. Telecommunication lines already serve the Project site (the ranch house), so would require only a minor extension if the Project elects to have a land line at the processing site. For these reasons, the Project would have no impact due to the relocation or construction of these new or expanded utilities. Electrical and natural gas facilities are discussed in Section

3.6, Energy. The environmental impacts of installing additional groundwater wells are discussed in Section 3.10, Hydrology and Water Quality.
c) Result in a determination by the wastewater treatment provider which serves or may serve the project that it has adequate capacity to serve the project’s projected demand in addition to the provider’s existing commitments. The Project would not be served by a municipal wastewater treatment provider. The Project includes installation of an on-site septic system to treat wastewater from facility restrooms. No industrial wastewater would be generated that would require treatment by a wastewater treatment provider. Water used during aggregate processing would be collected and reused. Therefore, the Project would have no impact on wastewater treatment.

3.14.4.3 Project Impacts
Impact 3.14-1: The Project would increase demand for water supply. (Less than Significant) This impact addresses Significance Criterion (b).

Mountain View City CouncilApril 25, 2023

Mountain View City Council
April 25, 2023