Napa City Council
September 2, 2025

ENVIRONMENTAL CHECKLIST
Napa Hidden Glen Remediation Project 74 RCH Group
Draft Initial Study/Mitigated Negative Declaration July 2025 result in any changes in crime that would warrant changes to police protection service ratios and/or response times. Therefore, the Project would result in a less-than-significant impact.
a.iii-v) No Impact. The Project consists of short-term remediation activities and would not result in development or a change from existing operations at the vacant property. Because the Project does not propose development or a change in activities on the Project site, the Project would not result in an increase in employment. Therefore, the Project would not warrant a need for new schools, parks, or other public facilities, and would result in no impact.
_________________________

RECREATION
Issues (and Supporting Information Sources):

Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporation
Less Than
Significant
Impact No Impact

16. RECREATION — Would the proposed project:
a) Increase the use of existing neighborhood and regional parks or other recreational facilities such that
substantial physical deterioration of the facilities would occur or be accelerated?
☐ ☐ ☐ ☒
b) Include recreational facilities or require the
construction or expansion of recreational facilities
that might have an adverse physical effect on the
environment?
☐ ☐ ☐ ☒
Discussion
a, b) No Impact. The Project consists of short-term remediation activities and would not result in development or a change from existing operations at the vacant property. Because the Project does not propose development or a change in activities on the Project site, the Project would not increase the use of existing recreational facilities such that physical deterioration of existing facilities would occur or be accelerated, and would not warrant new or expanded recreational facilities. Therefore, the Project would result in no impact. _________________________

ENVIRONMENTAL CHECKLIST
Napa Hidden Glenn Remediation Project 75 RCH Group
Draft Initial Study/Mitigated Negative Declaration July 2025

TRANSPORTATION
Issues (and Supporting Information Sources):

Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporation
Less Than
Significant
Impact No Impact

17. TRANSPORTATION — Would the proposed project:
a) Conflict with a program plan, ordinance or policy
addressing the circulation system, including transit,
roadway, bicycle and pedestrian facilities?
☐ ☐ ☒ ☐
b) Would the project conflict or be inconsistent with CEQA Guidelines section 15064.3, subdivision (b)? ☐ ☐ ☒ ☐
c) Substantially increase hazards due to a geometric
design feature (e.g., sharp curves or dangerous
intersections) or incompatible uses (e.g., farm
equipment)?
☐ ☐ ☒ ☐
d) Result in inadequate emergency access? ☐ ☐ ☒ ☐
Introduction
Senate Bill 743
Senate Bill 743 (SB 743; Steinberg, 2013) governs the application of new State CEQA Guidelines for addressing transportation impacts based on Vehicle Miles Traveled (VMT). It was codified in Public Resources Code §21099, required changes to the guidelines implementing CEQA (State CEQA Guidelines) (Cal. Code Regs., Title 14, Div. 6, Ch. 3, § 15000 et seq.) regarding the analysis of transportation impacts. The Governor’s Office of Planning and Research (OPR) has proposed, and the California Natural Resources Agency (Agency) has certified and adopted, changes to the State CEQA Guidelines that identify VMT as the most appropriate metric to evaluate a project’s transportation impacts. With the Agency’s certification and adoption of the changes to the State CEQA Guidelines, automobile delay, as measured by “level of service” and other similar metrics, generally no longer constitutes a significant environmental effect under CEQA. (Pub. Resources Code, § 21099, subd. (b)(3).)”
The OPR’s Technical Advisory on Evaluating Transportation Impacts in CEQA (OPR, 2018) provides general direction regarding the methods to be employed and significance criteria to evaluate VMT impacts, absent policies adopted by local agencies.

Project Trip Generation
As noted in the Project Description, the Project site would be accessed via Pascale Place where construction crews would park, and equipment can be staged and transported to the Project site or by an alternative access road that would be constructed between the Project site and El Monte Way. Project operations would not result in any new vehicle trips.

Discussion
a) Less-than-Significant Impact. The Project consists of short-term remediation activities and would not result in development or a change from existing operations at the vacant property. Typical of any construction project, the Project could result intermittent

ENVIRONMENTAL CHECKLIST
Napa Hidden Glen Remediation Project 76 RCH Group
Draft Initial Study/Mitigated Negative Declaration July 2025 stoppages of vehicles, bicycles, or pedestrians for heavy equipment and haul trucks to safely enter and exit the site. The Project would not substantially change the pedestrian or bicycle traffic in the area and would not significantly impact or require changes to the design of any existing or planned bicycle or pedestrian facilities. Because the Project does not propose development or a change in activities on the Project site, the Project would not generate new trips during operations and therefore would not conflict with any program, plan, or policy addressing the circulation system in the City. Therefore, the Project would result in a less-than-significant impact. b) Less-than-Significant Impact. VMT refers to the amount and distance of vehicle travel attributable to a project. VMT generally represents the number of vehicle trips generated by a project multiplied by the average trip length for those trips. For CEQA transportation impact assessment, VMT is calculated using the origin-destination VMT method, which accounts for the full distance of vehicle trips to and from the Project site.

The OPR’s Technical Advisory on Evaluating Transportation Impacts in CEQA provides general direction regarding the methods to be employed and significance criteria to evaluate VMT impacts, absent policies adopted by local agencies. The directive addresses several aspects of VMT impact analysis, and is organized as follows:
 Screening Criteria: Screening criteria are intended to quickly identify when a project should be expected to cause a less-than-significant VMT impact without conducting a detailed study.
 Significance Thresholds: Significance thresholds define what constitutes an acceptable level of VMT and what could be considered a significant level of VMT requiring mitigation.
 Analysis Methodology: These are the potential procedures and tools for producing VMT forecasts to use in the VMT impact assessment.
 Mitigation: Projects that are found to have a significant VMT impact based on the County’s significance thresholds are required to implement mitigation measures to reduce impacts to a less-than-significant level (or to the extent feasible).

Screening Criteria
Screening criteria can be used to quickly identify whether sufficient evidence exists to presume a project would have a less-than-significant VMT impact without conducting a detailed study. However, each project should be evaluated against the evidence supporting that screening criteria to determine if it applies. Projects meeting at least one of the criteria below can be presumed to have a less than significant VMT impact, absent substantial evidence that the project will lead to a significant impact.

The extent to which the Project qualifies under each criterion is noted below.  Regional Truck Traffic: The OPR directive specially focuses on the need to evaluate residential and employment-based travel, either from the standpoint of

ENVIRONMENTAL CHECKLIST
Napa Hidden Glenn Remediation Project 77 RCH Group
Draft Initial Study/Mitigated Negative Declaration July 2025 home-based trips or through evaluation of commute trips associated with employment centers. Consistent with Section 15064.3 of the State CEQA Guidelines, impacts from regional truck traffic are not included in the VMT estimates, but are considered from an operational standpoint as they relate to safety.  Small Projects: Defined as a project that generates 110 or fewer average daily vehicle trips.
 Affordable Housing: Defined as a project consisting of deed-restricted affordable housing.
 Local-Serving Non-Residential Development: The directive notes that local serving retail uses can reduce travel by offering customers more choices in closer proximity.

Local serving retail uses of 50,000 square feet or less can be presumed to have a lessthan-significant impact.  Projects in Low VMT-Generating Area: Defined as a residential or office project that is in a VMT efficient area based on an available VMT Estimation Tool. The project must be consistent in size and land use type (i.e., density, mix of uses, transit accessibility) as the surrounding built environment.
 Proximity to High Quality Transit: The directive notes that employment and residential development located within a half mile of a high-quality transit corridor can be presumed to have a less-than-significant impact.

Impact Conclusion
The extent to which the Project’s VMT impacts can be presumed to be less than significant has been determined based on review of the OPR’s screening criteria and general guidance. The OPR’s Small Project criteria is applicable to the Project. The Project would not generate long term automobile trips. Project construction would require an average of 10 workers per day resulting in approximately 20 automobile trips per day.

The Project would also generate between approximately 14 to 24 haul truck trips per day depending upon the given phase (for waste-impacted soil export or clean fill import).

Consistent with Section 15604.3 of the State CEQA Guidelines, impacts from regional truck traffic are not included in the VMT estimates. As the 110 average daily trips threshold would not be exceeded, the Project’s VMT impacts can be presumed to be less than significant. Therefore, the Project would result in a less-than-significant impact. c) Less-than-Significant Impact. The Project consists of short-term remediation activities and would not result in development or a change from existing operations at the vacant property. The temporary access road for the Project would not be accessible to the public and the Project would not result in permanent changes to the existing roadways. The Project would not involve any new hazardous design or feature. The Project would not result in permanent changes to roadways and would not create any significant impacts to pedestrians, bicyclists, or traffic operations. Therefore, the Project would result in a lessthan-significant impact.

ENVIRONMENTAL CHECKLIST
Napa Hidden Glen Remediation Project 78 RCH Group
Draft Initial Study/Mitigated Negative Declaration July 2025 d) Less-than-Significant Impact. The Project would not substantially increase hazards to vehicle safety due to increased traffic, which could result in inadequate emergency access.

The Project site is vacant, and no emergency vehicle access is required. In addition, the addition of traffic from Project construction traffic would not result in any significant changes to emergency vehicle response times in the area. Therefore, the Project would result in a less-than-significant impact.

References
California Governor’s Office of Planning and Research (OPR). 2018. Technical Advisory on Evaluating Transportation Impacts in CEQA, April 2018.
_________________________

ENVIRONMENTAL CHECKLIST
Napa Hidden Glenn Remediation Project 79 RCH Group
Draft Initial Study/Mitigated Negative Declaration July 2025

TRIBAL CULTURAL RESOURCES
Issues (and Supporting Information Sources):

Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporation
Less Than
Significant
Impact No Impact

18. TRIBAL CULTURAL RESOURCES —
Would the proposed project cause a substantial adverse change in the significance of a tribal cultural resource, defined in Public Resources Code section 21074 as either a site, feature, place, cultural landscape that is geographically defined in terms of the size and scope of the landscape, sacred place, or object with cultural value to a California Native American tribe, and that is:
a) Listed or eligible for listing in the California Register of Historical Resources, or in a local register of historical resources as defined in Public Resources Code section
5020.1(k), or
☐ ☐ ☒ ☐
b) A resource determined by the lead agency, in its
discretion and supported by substantial evidence, to be significant pursuant to criteria set forth in subdivision (c) of Public Resources Code Section 5024.1. In applying
the criteria set forth in subdivision (c) of Public
Resources Code Section 5024.1, the lead agency shall
consider the significance of the resource to a California Native American Tribe.
☐ ☒ ☐ ☐
Introduction
Tribal Cultural Resources (TCR’s) include sites, features, places, cultural landscapes, and sacred places or objects that have cultural value or significance to a Tribe. To qualify as a TCR, the resource must either: 1) be listed on, or be eligible for, listing on the California Register of Historical Resources (CRHR) or other local historic register; or 2) constitute a resource that the lead agency, at its discretion and supported by substantial evidence, determines should be treated as a TCR (PRC §21074). Under Assembly Bill 52 (AB 52) tribal representatives are considered experts appropriate for providing substantial evidence regarding the locations, types, and significance of TCRs within their traditional and cultural affiliated geographic area, and therefore, the identification and analysis of TCRs should involve government-to-government tribal consultation between the CEQA lead agency and interested tribal groups and/or tribal persons. (PRC §21080.3.1(a)).

The City of Napa notified the following tribes requesting Assembly Bill (AB) 52 notification for projects subject to CEQA.

1. Confederated Villages of Lisjan Nation

2. Yocha Dehe Wintun Nation
The City sent project notification letters via certified mail to both tribes and neither tribe requested formal consultation within 30 days of receipt of the notification letter. No TCRs were discovered during the cultural resources investigation of the Project site (NIC, 2025).

ENVIRONMENTAL CHECKLIST
Napa Hidden Glen Remediation Project 80 RCH Group
Draft Initial Study/Mitigated Negative Declaration July 2025 Discussion
a) Less-than-Significant Impact. No cultural resources either listed or eligible for listing by the State or local listing were identified on the Project site as a result of the records search and AB 52 consultation. Therefore, the Project would result in a less-thansignificant impact. b) Less-than-Significant Impact with Mitigation. Archival research and an intensive field survey did not identify any significant archaeological or cultural resources within the Project area (NIC, 2025). The survey noted that due to the burning of waste products, earth moving, introduction of outside soils, use of heavy machinery, and contamination of the Project area, the likelihood of finding buried cultural resources, archaeological resources, or human remains is low. Furthermore, Mitigation Measures CUL-1 through CUL-2 require procedures for the inadvertent discovery of cultural resources and tribal cultural resources and human remains. Therefore, the Project would result in a less-thansignificant impact.

References
Natural Investigations Company (NIC), 2025. Cultural Resources Investigation for the Napa Hidden Glen Dump Remediation, Napa County. March 2025.
_________________________

ENVIRONMENTAL CHECKLIST
Napa Hidden Glenn Remediation Project 81 RCH Group
Draft Initial Study/Mitigated Negative Declaration July 2025

UTILITIES AND SERVICE SYSTEMS
Issues (and Supporting Information Sources):

Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporation
Less Than
Significant
Impact No Impact

19. UTILITIES AND SERVICE SYSTEMS — Would the
proposed project:

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) 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 that would 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?
☐ ☐ ☒ ☐
e) Comply with federal, state, and local management and reduction statutes and regulations related to solid
waste?
☐ ☐ ☒ ☐
Discussion
a) No Impact. The Project consists of short-term remediation activities and would not result in development or a change from existing operations at the vacant property. The Project site would not require new utilities related to water and wastewater treatment, stormwater, telecommunication, natural gas or electric power services. Therefore, the Project would result in no impact.
b) No Impact. The Project consists of short-term remediation activities and would not result in development or a change from existing operations at the vacant property. The Project would have no long-term water demand and would not adversely affect the water supply.

Therefore, the Project would result in no impact.
c) No Impact. The Project consists of short-term remediation activities and would not result in development or a change from existing operations at the vacant property. The Project would not generate any wastewater and would not require additional capacity beyond the wastewater treatment. Therefore, the Project would result in no impact. d, e) Less-than-Significant Impact. The Project consists of short-term remediation activities and would not result in development or a change from existing operations at the vacant property. Construction of the Project would not generate a significant amount of solid

ENVIRONMENTAL CHECKLIST
Napa Hidden Glen Remediation Project 82 RCH Group
Draft Initial Study/Mitigated Negative Declaration July 2025 waste as only soil would be removed from the site. Waste-impacted soil that is hauled offsite would be hauled to an appropriate landfill for disposal and would not exceed the capacity of local landfills. The Project would comply with all federal, state, and local statutes and regulations related to solid waste. Therefore, the Project would result in a less-than-significant impact.
_________________________

WILDFIRE
Issues (and Supporting Information Sources):

Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporation
Less Than
Significant
Impact No Impact

20. WILDFIRE —
If located in or near state responsibility areas or lands classified as very high hazard severity zones, would the proposed project:
a) Substantially impair an adopted emergency response
plan or emergency evacuation plan? ☐ ☐ ☐ ☒
b) Due to slope, prevailing winds, and other factors,
exacerbate wildfire risks, and thereby expose project
occupants to, pollutant concentrations from a wildfire
or the uncontrolled spread of a wildfire?
☐ ☐ ☐ ☒
c) Require the installation or maintenance of associated infrastructure (such as roads, fuel breaks, emergency
water sources, power lines or other utilities) that may exacerbate fire risk or that may result in temporary or ongoing impacts to the environment?
☐ ☐ ☐ ☒
d) Expose people or structures to significant risks,
including downslope or downstream flooding or
landslides, as a result of runoff, post-fire slope
instability, or drainage changes?
☐ ☐ ☐ ☒
Introduction
Areas where the state has financial responsibility for wildland fire protection are known as state responsibility areas (SRA). The Department of Forestry and Fire Protection (CALFIRE) is responsible for fire prevention and suppression in SRA. Areas where local governments have financial responsibility for wildland fire protection are known as local responsibility areas (LRA).

The Project site is not located in a SRA or a very high fire hazard severity zone (VHFHSZ). The Project is located in an LRA and is within a Moderate severity zone. The City of Napa Fire Department provides fire protection services to the City of Napa. The City of Napa Fire Department operates five stations throughout the City (City of Napa, 2022). The nearest fire station to the site is the Napa Fire Department Station 1, located approximately 1.3 miles west of the Project site.

Discussion
a) No Impact. The Project would not involve the closure or alteration of any existing evacuation route that would be important in the event of a wildfire. The Project would not

ENVIRONMENTAL CHECKLIST
Napa Hidden Glenn Remediation Project 83 RCH Group
Draft Initial Study/Mitigated Negative Declaration July 2025 impede or require diversion of rescue vehicles or evacuation traffic in the event of a wildfire. Therefore, the Project would result in no impact. b) No Impact. There are no elements of the Project that would exacerbate wildland fire risk in the Project area due to slope, prevailing winds, and other factors. Therefore, the Project would result in no impact.
c) No Impact. There are no elements of the Project that would exacerbate wildland fire risk in the Project area, which is a regularly mowed vacant lot. Therefore, the Project would result in no impact.
d) No Impact. There are no elements of the Project that would expose people or structures to flooding or landslides by runoff flow, post-fire instability, or drainage changes.

Therefore, the Project would result in no impact.

References
CALFIRE. 2025. Fire Hazard Severity Zones in State Responsibility Area, https://osfm.fire.ca.gov/what-we-do/community-wildfire-preparedness-and-mitigation/firehazard-severity-zones, accessed April 9, 2025 _________________________

ENVIRONMENTAL CHECKLIST
Napa Hidden Glen Remediation Project 84 RCH Group
Draft Initial Study/Mitigated Negative Declaration July 2025

MANDATORY FINDINGS OF SIGNIFICANCE
Issues (and Supporting Information Sources):

Potentially
Significant
Impact
Less Than
Significant with
Mitigation
Incorporation
Less Than
Significant
Impact No Impact

21. MANDATORY FINDINGS OF SIGNIFICANCE —
Would the proposed project:

a) Have the potential to substantially degrade the
quality of the environment, substantially reduce the
habitat of a fish or wildlife species, cause a fish or
wildlife population to drop below self-sustaining
levels, threaten to eliminate a plant or animal
community, substantially reduce the number or
restrict the range of a rare or endangered plant or
animal, or eliminate important examples of the major
periods of California history or prehistory?
☐ ☒ ☐ ☐
b) Have impacts that are individually limited, but
cumulatively considerable? (“Cumulatively
considerable” means that the incremental effects of a
project are considerable when viewed in connection
with the effects of past projects, the effects of other current projects, and the effects of probable future
projects)?
☐ ☒ ☐ ☐
c) Have environmental effects that would cause
substantial adverse effects on human beings, either
directly or indirectly?
☐ ☐ ☒ ☐
Discussion
a) Less-than-Significant Impact with Mitigation. The Project would not substantially degrade the quality of the environment, reduce fish or wildlife populations, or eliminate important examples of major periods of California history or pre-history. As noted in the Cultural Resources section, there are no features onsite of prehistoric or historic significance. Thus, the Project would not eliminate important examples of the major periods of California history or prehistory and would not significantly impact any resource that would qualify for listing as eligible on the CRHR. As noted in the Biological Resources section, implementation of Mitigation Measures BIO-1 and BIO2 would reduce impacts to special status animal species. Therefore, the Project would result in a less-than-significant impact with mitigation. b) Less-than-Significant Impact with Mitigation. According to the City of Napa, there is one proposed roadwork project within one mile of the project site. This includes the Coombsville Road Roadway Rehabilitation Project (Pascale Place to City Limits, located approximately 0.4 miles to the east of the Project site). The Project is proposed to include pavement and striping work, and possible concrete and storm drain improvements.

As described in the preceding sections of this Initial Study, the Project would result in no impacts to agricultural and forest resources, land use and land use planning, mineral resources, population and housing, recreation, or wildfire. Because the Project would have no impact for these topic areas, there is no potential for the Project to have cumulatively considerable impacts.

ENVIRONMENTAL CHECKLIST
Napa Hidden Glenn Remediation Project 85 RCH Group
Draft Initial Study/Mitigated Negative Declaration July 2025 As described in the preceding sections of this Initial Study, the Project would result in less than significant impacts to aesthetics, energy, geology and soils, GHG emissions, hazards and hazardous materials, hydrology and water quality, noise, public services, transportation, and utility and service systems. The Project is consistent with the land use and zoning designations for the parcel and would not conflict with applicable land use policies or regulations.

As noted in the Air Quality section, the BAAQMD CEQA Air Quality Guidelines recommend that cumulative air quality effects from criteria air pollutants also be addressed by comparison to project-level significance thresholds. These thresholds were developed to identify a cumulatively considerable contribution to a significant regional air quality impact. As disclosed in the Air Quality section, the Project-related construction emissions would be below BAAQMD’s average daily significance thresholds. The incorporation of mitigation measures for fugitive dust during construction of the Project would ensure air quality impacts would be less than significant with mitigation. Therefore, the Project would not result in a cumulatively considerable net increase of emissions of criteria air pollutants and precursors and there is no potential for the Project to have cumulatively considerable air quality impacts.

As noted in the Biological Resources section, the Project site is highly disturbed, making it unsuitable for special-status plants to occur. In addition, the Project site lacks the hydrological and topographical conditions to support special-status plant species. The Project site does not contain any wetlands or other natural aquatic habitat features, such as stream channels or drainages. Mitigation measures for special status animal species (preconstruction surveys for nesting birds and bats) would reduce impacts to a less than significant level. Therefore, there is no potential for the Project to have cumulatively considerable biological resource impacts.

As noted in the Cultural Resources and Tribal Cultural Resources sections, no historical resources exist on the Project site and the Project area exhibits a low level of sensitivity for cultural resources, paleontological resources, or traces of early Native American activity. Due to a lack of identified cultural resources, the Project would result in a lessthan-significant impact with mitigation. Therefore, there is no potential for the Project to have cumulatively considerable cultural or tribal cultural resource impacts.

Considering the factors addressed above, the Project would not have a cumulatively considerable impact on any of the environmental factors evaluated in this Initial Study with mitigation incorporated. Therefore, cumulative impacts would be less than significant with mitigation incorporated and the Project would not result in cumulatively considerable impacts when viewed in connection with the effects of past projects, the effects of other current projects, and the effects of probable future projects. c) Less-than-Significant Impact. As described in the preceding sections of this Initial Study, the Project would not result in impacts that would result in substantial adverse

ENVIRONMENTAL CHECKLIST
Napa Hidden Glen Remediation Project 86 RCH Group
Draft Initial Study/Mitigated Negative Declaration July 2025 effects on human beings, either directly or indirectly. Therefore, the Project would result in a less-than-significant impact with mitigation.
_________________________

APPENDIX A

SITE PHOTOS

City of Napa
Hidden Glen Remediation
Site Photos
Prepared by:

City of Napa Utilities Department
for
CalRecycle Legacy Disposal Abatement
Partial Grant Program Application
October 16, 2024
CITY 01=
NAPA

City Hall: 955 School Street, Napa CA 94559  Mailing Address: P.O. Box 660, Napa CA 94559  (707) 257-9500  www.cityofnapa.org Photo 1 – Aerial View of Project Site (north is top of photo)

City Hall: 955 School Street, Napa CA 94559  Mailing Address: P.O. Box 660, Napa CA 94559  (707) 257-9500  www.cityofnapa.org Photo 2 – Project Site (looking north towards house on Lot 13) Photo 3 – Project Site (looking east towards quarry cliffs)

City Hall: 955 School Street, Napa CA 94559  Mailing Address: P.O. Box 660, Napa CA 94559  (707) 257-9500  www.cityofnapa.org Photo 4 – Project Site (looking south towards house on Lot 6) Photo 5 – Project Site (looking south-west towards Lots 7 & 8)

City Hall: 955 School Street, Napa CA 94559  Mailing Address: P.O. Box 660, Napa CA 94559  (707) 257-9500  www.cityofnapa.org Photo 6 – Project Site (looking west with house on Lot 6 to the left) Photo 7 – Project Site (looking west with house on Lot 9 to the right)

City Hall: 955 School Street, Napa CA 94559  Mailing Address: P.O. Box 660, Napa CA 94559  (707) 257-9500  www.cityofnapa.org Photo 8 – Project Site (looking north-west towards Lots 9 & 10) Photo 9 – Methane Gas Monitoring Well #2 Along Fence with Lot 7 (looking south-west)

City Hall: 955 School Street, Napa CA 94559  Mailing Address: P.O. Box 660, Napa CA 94559  (707) 257-9500  www.cityofnapa.org Photo 10 – Project Site (looking south-west towards Lot 8 w/ Pascal Place in upper right)
Photo 11 – Project Site Along Pascal Place (looking south)

APPENDIX B

REMEDIAL ACTION PLAN (RAP)

Remedial Action Plan
Hidden Glen Dump
Coombsville Road
Napa, California
SWIS No. 28-AA-0028
Napa County Local Enforcement Agency
1195 Third Street, Suite 210 I Napa, California 94559
October 16, 2024 | Project No. 109558001
Geotechnical | Environmental | Construction Inspection & Testing | Forensic Engineering & Expert Witness Geophysics | Engineering Geology | Laboratory Testing | Industrial Hygiene | Occupational Safety | Air Quality | GIS Geotechnlcal & Environmental Sciences Consultants
, .. I

5710 Ruffin Road | San Diego, California 92123 | p. 858.576.1000 | www.ninyoandmoore.com Remedial Action Plan
Hidden Glen Dump
Coombsville Road
Napa, California
SWIS No. 28-AA-0028
Mr. Peter Ex, REHS
Napa County Local Enforcement Agency
1195 Third Street, Suite 210 I Napa, California 94559
October 16, 2024 | Project No. 109558001
Nathan Diem
Senior Geologist
Beth Abramson-Beck, PG
Project Engineer
NDD/BAB/mp
J(ln90&/(I.Oore
G8ollcllnlCII & Envlronmllltal Sclt11Ct1 Con1ulllntl

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024 i

CONTENTS
1 INTRODUCTION 1
2 BACKGROUND 2
3 SITE DESCRIPTION 4
4 OWNERSHIP 4
5 PHYSICAL SETTING 4

5.1 Topography 5

5.2 Regional and Site Geology 5

5.3 Groundwater 6
6 REMEDIAL ACTION 8

6.1 Remedial Action Objectives 8

6.2 Pre-Remedial Action Site Preparation and Notifications 9

6.3 Site Health and Safety Plan (SHSP) 9

6.4 Community Health and Safety Plan 9

6.5 Utility Clearance 10

6.6 Site Access 10

6.7 Waste Excavation 10

6.8 Waste Disposition – Reconsolidation 11

6.9 Waste Disposition – Neighboring Property
Waste Reconsolidation Option 11

6.10 Waste Disposition – Offsite Disposal 12

6.11 Temporary Stockpiling and Management 12

6.11.1 Stockpile Sampling and Characterization for Offsite Disposal 12

6.12 Imported Fill Soil 13

6.13 Best Management Practices

6.14 Excavation Sampling

6.15 Field Documentation

6.16 Dust Control and Air Monitoring Plan

6.17 Site Restoration
14 14
14 14
15

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024 ii 7 LIMITATIONS 15
8 REFERENCES 17

FIGURES
Figure 1 – Site Location
Figure 2 – Site Plan
Figure 3 - Planned Remedial Action
Figure 4 - Planned Remedial Action – Neighboring Waste Grading Alternative

APPENDICES
A – Closed Disposal Site Inspection Report Hidden Glen Dump 4/23/24 B – Architect Grading Design Plans
C – 2018 Langan Soil Sample Results
D - Site Specific Health and Safety Plan
E - Community Health and Safety Plan
F – Alternative Acceptance of Neighboring Property Waste Soil Grading Plans G – DTSC Information Advisory – Clean Imported Fill

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024 1 1 INTRODUCTION
Ninyo & Moore is pleased to submit this Remedial Action Plan (RAP) for a portion of the Hidden Glen Dump, (dump) located near the intersection of Pascale Place and Glory Court in Napa, California (Figure 1). The waste disposal site (WDS) is listed as “Hidden Glen Dump” in the CalRecycle Solid Waste Information System (SWIS) database and assigned SWIS No. 28-AA0028. According to the database, the dump is listed as an unpermitted, closed, solid waste disposal site (WDS). The City-owned property referred to as “Parcel A” corresponds to a 2.18-acre area and is assigned Napa County Assessor Parcel Number (APN) 045-411-022-000 (Figure 2).

According to the SWIS database, the waste type is indicated as “There are no Waste Types” (likely undocumented/unknown). Information pertaining to “closure type, volume Unit Type, Remaining Capacity, Total Acreage, Disposal Acreage, permitted depth and elevation and depth are not available. The WDS is inspected quarterly by the County of Napa Environmental Health, Solid Waste Local Enforcement Agency (LEA). The latest inspection report, dated April 23, 2024, states “There are no Violations and No Areas of Concern (Appendix A). The April inspection report noted soil and debris was illegally disposed of on the west side of the property from an adjacent property, Lot 9.

On November 26, 2019 the LEA issued a Notice of Comply to the City which required submittal of a Work Plan to ensure that State Minimum Standards are addressed at the City owned property and in compliance with Title 27 of the --- Code of regulations. This RAP is being submitted to comply with the notice.

This RAP pertains to the portion of the dump that is owned by the City of Napa (City) and includes conducting the proposed remedial action activities on City-owned property. The planned remedial action for the City-owned property consists of waste excavation at locations and to depths to meet state minimal standards for waste disposal sites and be protective of human health, and on-site reconsolidation of the removed wastes as generally shown on Figure 3. Detailed remediation plans are included in Appendix B. The planned remedial activities will be conducted on City-owned property; however, the City may additionally remove some wastes in the areas of adjacent residential properties to provide a sloped transition of the soil cover across property lines referred to as “feathering”. This RAP also includes the possibility of accepting waste soil from adjacent properties and reconsolidating and covering on City property as shown in Appendix F.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024 2 2 BACKGROUND
The background information contained in this section focuses on the previous Closure Plans for the dump, reports documenting closure activities and related regulatory agency correspondence, and subsurface investigations at adjacent residences. The background information was obtained from publicly available documents in the CalRecycle SWIS database and pertains to wastes located outlying the capped portion of the dump that are specifically relevant to this RAP.

Initially the dump was an excavated quarry that operated into the 1940s. Reportedly, groundwater was encountered when the quarrying operations were at a depth of about 70 to 80 feet (below ground surface (bgs). Reportedly, the quarry was abandoned due to the presence of groundwater.

Sometime after quarry operations ended, the excavation was used as a general garbage dump by a private operator. Reportedly, “garbage” was dumped and then burned “and spread as a landfill.” It was stated that it was possible that “old” automobiles from a local demolition derby were also abandoned at the dump. In the early l960's, the dump reportedly was abandoned when the South County landfill became operational. The City reportedly began using the Hidden Glen Dump to dispose tree prunings and brush, along with asphalt and concrete wastes. The brush and prunings were reportedly burned “and spread.”
Several closure plans (aka remedial action plans) were previously prepared for the dump and remedial action activities were conducted to close the site. ENGEO (1988) prepared a closure plan consisting of capping the waste disposal site “in place.” In 1990, Harding Lawson Associates (HLA) (1990) prepared an addendum to the closure plan that maintained the planned “in-place capping” of the dump. In April 2000 McClaren-Hart prepared a Closure Plan for the Hidden Glen Dump (McClaren-Hart, Inc, 2000) that was generally consistent with the previous 1988 ENGEO and 1990 HLA closure plans and similarly proposing capping the waste disposal site “…in place and dedicating the site as open space as part of a planned residential development of the surrounding site.” The closure plan proposed to cap in place the dump and reportedly “…gain agency concurrence for closure, which is sought by the land owner to allow him to proceed with planned residential development of the overall 14-acre site.” Reportedly the 1990 McClaren-Hart Closure Plan report was prepared as an addendum to the 1988 Closure Plan.

In general, the McClarren-Hart Closure Plan described methods proposed to cap in place the dump and obtain regulatory agency concurrence for closure which was being sought by the land owner to allow them to proceed with the planned residential development of the overall 14-acre site, a portion of which included the dump. Post closure activities were indicated as consisting of a 5-year cap and methane monitoring program even though methane was not expected to be encountered at levels of environmental concern.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024 3 In January 2002, Geotrans submitted a documentation report of the waste cap construction on behalf of the Napa Garbage Service that included as-built drawings, liner test results, compaction test results, site photographs, and a description of the work performed. It was stated that the “landfill” cap was constructed in accordance with the design specifications and closure plan requirements.

Geotrans stated that the closure was performed with oversight and direction from the Water Board, CIWMB and the LEA and in general accordance with the April 6, 2000 closure plan prepared by McLaren/Hart, Inc. titled, “Closure Plan, Hidden Glen Landfill, Napa, California” as amended by the December 6, 2000 letter prepared by Geotrans titled, “Addendum to April 6, 2000 Hidden Glenn Landfill Closure Plan, Napa, California.” GeoTrans stated that the construction documentation report indicated that “landfill closure” included importing and stockpiling clean fill material for use as foundation fill and protective soil cover; clearing and grubbing the waste area surface; placing and grading foundation fill soils over the waste materials; installing a cap system consisting of a geosynthetic clay liner (GCL), 80-mil high density polyethylene (HDPE ) layer, and geocomposite drainage layer; placing protective soils and top soil over the cap; placing a hydroseed mixture on the topsoil; and installing surface water drainage and erosion control features.

Beginning in September 2018, Langan conducted subsurface site investigations (drilling and sampling) of residential properties at Lots 6, 7, 8, 9 and 10, outlying the capped portion of the Hidden Glen Dump and on the flag section of the City owned property. Langan indicated that the purpose of their investigations was to collect “subsurface information” to develop a plan for remedial action “to address debris impacts in shallow soil on the five lots and, if needed, on adjacent areas between the lots and the landfill footprint.” The results of their investigations indicate that the lateral extent of the waste disposal site extends beyond the area that was capped and relatively shallow wastes extended within the buffer zone onto the residential properties. In addition, waste was observed within the flag ship area (frontage along Pascale Place, Figure 2).

These wastes contain elevated lead concentrations at some locations. Soil sample results and figures are included in Appendix C (Langan, 2019a,b,c,d,e).

The Langan reports were provided to the LEA and in response the LEA issued a Notice to Comply letter to the City on November 26, 2019. The Notice to Comply letter required submittal of a Work Plan to ensure that State Minimum Standards are addressed at the City owned property and in compliance with Title 27 of the --- Code of regulations. This RAP is being submitted to comply with the notice.

On June 29, 2020, the LEA issued a letter to the City of Napa requiring submittal of a workplan to ensure that State Minimum Standards are addressed at the City-owned parcel and in compliance with Title 27 of the California Code of Regulations. To comply with State Minimal Standards, the

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024 4 letter requires the City to remove and/or cover spillover waste along the flag section and the buffer zone (Figure 2). The LEA describes two options to address waste in the flag section and the buffer zone; option 1 full waste removal and option 2 leaving the waste in-place and capping. This RAP proposes to excavate, reconsolidate waste on site, and cap waste with a minimum of two feet of clean soil.
3 SITE DESCRIPTION
The site as it pertains to the RAP is the City-owned Parcel A consisting of the capped portion of the dump and the area between the capped area and the adjacent properties referred to as the buffer zone (Figure 2). The dump is located in a residential setting with wastes occurring at the previously capped portion of the dump, buffer zone and at adjacent residential properties downslope to the north, west, and south. Nearly vertical quarry walls along the east perimeter of the cap section contain the waste to the east. Adjacent residential properties are not separated by a road or other features. A cemetery is located across Pascale Place to the west.

The dump has three relatively recently constructed Landfill Gas (LFG) monitoring wells referred to as MW-1 through MW-3 (Figure 2). The wells were constructed in December 2020 and are monitored quarterly. The wells are dual and triple completions; MW-1 and MW-2 are constructed with screened intervals at 5 to 10 feet, 15 to 20 feet and 25 to 35 feet and MW-3 is constructed with two screened intervals at 5 to 10 feet and 15 to 20 feet. 4 OWNERSHIP
The following information for the Hidden Glen Dump was obtained from the SWIS database:

Site: Hidden Glen Dump
Coombsville Road
Napa, California
(SWIS No. 28-AA-0028)
GIS Coordinates Latitude: 38.2977 Longitude: -122.2679
Land Owner(s) City of Napa
955 School Street
Napa, California 94559
5 PHYSICAL SETTING
The following summarizes topographic, geologic, and hydrogeologic information for the site and/or vicinity, based upon documents reviewed, as referenced and/or our visual reconnaissance of the site.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024 5

5.1 Topography
The capped waste disposal area and buffer zone was observed to be relatively flat, with surface elevations reportedly ranging from approximately 120 to 130 feet MSL). On the northwest, north, and east sides are near vertical quarry walls (SCS Engineers, 2020). In general, the surface between the capped waste disposal area and Pascale Place to the west and Glory Court to the south slope downward to approximately 105 feet MSL.

5.2 Regional and Site Geology
The following is a description of the regional geology and site geology, based on early investigations, from the Closure Plan Addendum prepared by HLA.

The hills bordering the east side of Napa Valley are underlain, as is the site, by Pliocene age Sonoma Volcanics. The Sonoma Volcanics are a complex assemblage of volcanic, pyroclastic, and volcaniclastic rocks. The composition of these volcanics is highly variable and represents an accumulation of material erupted from numerous source vents. In addition, these deposits were typically deposited on irregular topographic surfaces and locally-on moderately steep slopes. As a result, the Sonoma Volcanics are commonly composed of highly lenticular or interfingered volcanic rocks of variable composition.

As observed at the site during previous investigations, several different lithologic rock types crop out on the surface, or were encountered during drilling, including: l) flow banded and brecciated rhyolite, 2) vitric tuff with lenses of perlitic rhyolite, a pyroclastic breccia and pumaceous ash flow tuff, and 3) poorly sorted lithic tuff breccia. These rocks exhibit rapid lateral variation and are gradational, such that they should be considered texturally and lithologically distinct zones within a single mappable unit.

Red-brown rhyolite crops out in the north portion of the site and occurs as blocks and small lenses (less than 10 feet thick) within dense vitric tuff in the southern portion of the site. The rhyolite is typically flow banded, although massive, flow breccia and explosion breccia textures were also observed. The matrix of the breccia consists of dense rhyolite. Overall, these rhyolite rocks are very hard, strong, and little weathered, with very little fracturing. Fractures that occur are related to cooling and are therefore random and discontinuous. The rhyolite is associated with some moderately consolidated tuff beds that typically occur near the base of the flow sequence.

A vitric tuff /pyroclastic breccia also crops out at the site and is light gray to green and generally hard and strong. This material is exposed on the west and south sides of the main quarry pit, and underlies the central portion of the pit as indicated from core samples during previous drilling

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024 6 (Engeo, 1988). Texturally, it ranges from dense vitric tuff to coarse pyroclastic breccia containing pumice and volcanic blocks and bombs accumulated near vents. In the quarry pit wall, this rock contains occasional hairline fractures (less than 1/16-inch) that are locally iron stained. Fractures observed in outcrop appear to be random. In addition, fractures are very infrequent in outcrops examined outside the quarry site, suggesting that some of the fractures observed in the pit wall may be due to prior quarry activities.

Brown, poorly sorted, lithic tuff breccia is exposed on the east wall of the main quarry area. This tuff contains abundant, angular, 2 to 3 foot blocks of rhyolite and less common, non-volcanic lithic fragments set in a dense brown ash matrix. Overall, the rock is hard, strong and infrequently fractured.

Most of the rocks observed in the cores or cuttings from the borings were similar to rocks observed in outcrop. However, in one boring (MW-F) (Figure 2), a dark red-brown silty clay mudstone-like material was encountered from 31 to 37 feet and is interpreted as a possible paleosol that formed between silicic eruptions. At 179 feet, a gray, fine- grained (aphanitic) basalt was penetrated. Immediately below the basalt, at 188 feet, ground water associated with cuttings of rounded volcanic gravels, sand, silt, and clay was found. The rounded gravels suggest that the cuttings were derived from a conglomerate or partially lithified river channel deposit that disaggregated during drilling. Lenses of volcaniclastic sediments and river deposits are not uncommon in the Sonoma Volcanics (Kunkel and Upson. 1960).

5.3 Groundwater
The following is a description of hydrogeologic and groundwater conditions at the site and surrounding area based on the compilation of assessment data by HLA for the Solid Waste Assessment Test (SWAT) (HLA, 1990). Groundwater data is from the groundwater and leachate monitoring wells installed to evaluate the site conditions to prepare a site closure plan in 1988 Based on the evaluation by HLA, “…ground-water flow through these volcanic rocks could be controlled by one or a combination of hydraulic conductivity of the bedrock matrix; hydraulic conductivity of through going discrete, or interconnected fracture sets; or hydraulic conductivity of contact zones between different volcanic units.”
Flow through the matrix of rocks is controlled by the abundance and interconnection of primary pores. The rocks examined on site are generally very hard and dense, and pores that exist, such as vesicles, are not interconnected. Thus, the hydraulic conductivity of the rock matrix of these rocks is very low.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024 7 Groundwater flow through hard rock could be controlled by either discrete throughgoing fractures or a network of interconnected fractures. Most fractures observed on site appear to be related to shrinkage during cooling of the volcanic rock. This type of fracture is random and restricted to individual cooling units. For example, a rhyolite flow may contain random cooling fractures that are either discontinuous within the flow or terminate at the adjacent unit that may or may not have its own set of cooling fractures. Considering the geologic setting and the field observations, the potential for either discrete, throughgoing fractures or a network of interconnected fractures appears to be low. Thus, the potential for groundwater flowing from the landfill into the bedrock and traveling into groundwater aquifers is considered low (HLA, 1990).

The volcanic rock beneath the site is extremely complex and highly variable. The irregular contact zones between different volcanic materials in the complex could conceivably be pathways for groundwater flow, particularly the top and bottom of a lava flow, which are often rubble zones developed by progressive movement during emplacement, a process referred to as auto brecciation. If the voids in the rubble are not filled during emplacement or by secondary alteration products, these zones can be permeable. In addition, some thin (less than 5 feet) interbedded lenses or beds of moderately consolidated pumaceous tuff occur locally in the pyroclastic sequence. These tuff beds appear moderately permeable and depending on the location, could behave as pathways for groundwater movement. Once groundwater gets into these zones, movement is controlled by the bedrock structure or the general strike and dip of the volcanic rocks. Some bedding plane contacts are essentially impermeable and behave as groundwater barriers. Fractures could conceivably be important locally in transmitting water from a flow or tuff unit to a permeable zone, if present (HLA, 1990).

Based on the HLA evaluation, water levels in bedrock monitoring wells associated with the site are highly variable. At the time, MW-C and MW-D are both dry (Figure 2). The water level in MW-A is at 76 feet above msl, whereas the water level in MW-F, located 400 feet northeast of MW-A, is at approximately 19 feet above msl. This variability in water levels suggests that the water-bearing zones encountered are not hydraulically connected. If these zones were in hydraulic connection, the wells on site would respond to a consistent and predictable gradient. The erratic water levels in adjacent wells further substantiates that ground-water flow beneath the site is not controlled by porous media type flow or by interconnected sets of fractures.

More recent monitoring of the three landfill gas wells at the site (MW-1 through MW-3, Figure 3) indicates that when last monitored in May 2024, groundwater was present in the shallow probe in MW-1 (total depth 10 feet bgs) at an approximate depth of 8 feet bgs. Groundwater was measured

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024 8 in the 30-foot LFG probe in MW-2 at a depth of 22 feet bgs and in the 20-foot LFG probe at a depth of 16 feet bgs.

Water was reportedly encountered in boring B-2 located within wastes (Figure 2). Water reportedly was not encountered in boring of B-1; however, this boring appears to be located on a high spot on the quarry floor. The core material of Boring B-1 was moist (HLA, 1990).

More recent monitoring of the three landfill gas wells at the site (MW-1 through MW-3, Figure 2 and Figure 3) indicates that when last monitored in May of 2024, groundwater was present in the shallow probe in MW-1 (total depth 10 feet bgs) at an approximate depth of 8 feet bgs.

Groundwater was measured in the 30-foot LFG probe in MW-2 at a depth of 22 feet bgs and in the 20-foot LFG probe at a depth of 16 feet bgs.
6 REMEDIAL ACTION
The planned remedial actions for the city-owned portion of the dump are consistent with restoration as an open-space (e.g., absence of buildings, playing fields, parking areas, equipment, etc.). The execution of the remedial action activities will be conducted in accordance with this LEA approved RAP. The remedial action will be performed by California-licensed contractors and a California licensed professional geologist, certified engineering geologist, or registered engineer or equivalent or under their direction. The following sections present the planned remedial action implementation. Remedial activities will be conducted in accordance with applicable rules and regulations imposed by the LEA, CalRecycle and the City of Napa.

6.1 Remedial Action Objectives
Remedial action objectives (RAOs) have been established for the dump to ensure the planned remedial actions:
1) are protective to human health and the environment,
2) meet applicable state minimum standards with respect to waste disposal sites (e.g., no exposed wastes, wastes where present will be adequately covered, etc.), 3) takes into account the types and locations of disposed wastes and future use of the site as open space,
4) is satisfactory to the LEA, CalRecycle and the City of Napa.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024 9

6.2 Pre-Remedial Action Site Preparation and Notifications Site preparation prior to implementing remedial action will include but not be limited to the following:
• Notify the LEA and CalRecycle of the proposed remedial action once a schedule has been established.
• The City will notify the adjacent property owners and their representatives of the planned remedial action.
• Delineate the work area boundaries including the “buffer zone” boundaries and the adjacent property lines.
• Install erosion control and Best Management Practices (BMPs) in accordance with the project Stormwater Pollution Prevention Plan (SWPPP).
• Identify and prepare site ingress and egress.

6.3 Site Health and Safety Plan (SHSP)
A site-specific worker health and safety plan (SHSP) was prepared by Ninyo & Moore under the direction of, and approved by a Certified Industrial Hygienist (CIH) (Appendix D). The SHSP will be used during the RAP implementation. The plan describes the required specific training and monitoring requirements to ensure workers are adequately protected, identified the potential chemical and physical hazards that may be encountered during the field activities and will be prepared in general compliance with Occupational Safety and Health Administration (OSHA) requirements. The plan addresses field procedures, personal protective equipment, anticipated contaminants, and established action levels for exposure to contaminants and contingency plans for emergencies that may arise during the fieldwork.

6.4 Community Health and Safety Plan
Due to the presence of an adjacent residential community, a CHSP was prepared for the remedial action under the direction of, and signed by a CIH (Appendix E). The primary purpose of the CHSP is to promote a safe and healthy environment for the public by reducing community exposures to potential hazards and nuisances from site/clean closure activities, and promoting community awareness of the planned site closure activities. The plan is intended to protect the public and surrounding properties from potential health and environmental hazards during the planned remedial activities. The CHSP addresses field procedures, anticipated contaminants, established action levels for exposure to contaminants, and contingency plans for emergencies that may arise during the fieldwork.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024 10

6.5 Utility Clearance
Subsurface utilities are not expected to be present in the remedial excavation areas based on the current open space use of the site. However, prior to commencing excavation activities, public utility locator Underground Service Alert (USA) will be notified of the planned project a minimum of 48 hours before field activities start so that they can contact representatives of utility companies in the area. The planned project area will be clearly marked with white paint or surveyors flagging as required by USA.

6.6 Site Access
Access to the site is limited due to the absence of access roads, presence of private properties generally surrounding the site and presence of steep slopes/near vertical quarry walls. The site is only accessible via Pascale Place by traversing the western portion of the City of Napa-owned Lot A (Figure 3). Temporary construction fencing will be placed at the site entrance along Pascale Place (Appendix B) and access to the site will be arranged in advance by the City of Napa.

6.7 Waste Excavation
The remedial action for the site generally consists of excavating and removing wastes in the buffer zone (Figures 2 and 3) (e.g., areas between the capped portion of the dump and the adjacent residential properties/lots) and reconsolidating these wastes onsite at the northern portion of the capped dump (Figure 3). As shown in the grading plans in Appendix B, and on Figure 3, wastes will be excavated to bedrock where feasible, to depths of approximately 10 to 20 inches. The depth of excavation will be reduced if bedrock is encountered at shallower depths. Conversely, the depth of excavation may extend beyond 20 inches if wastes are deeper to reach bedrock or the excavation may terminate in wastes in which case the wastes will be covered with 2 feet of clean imported soil. Where waste removal may not be possible due to access, stability and/or other restrictions, wastes remaining in place will be covered with two 2 feet of clean imported soil to meet state minimum standards. Soil/waste from the flag section of Parcel A (frontage along Pascale Place, Figure 3) will be removed down to bedrock.

The lateral extent of the waste removal will be based on agreements with the adjacent property owners. At a minimum, waste will be removed within the buffer zone and extend to the adjacent property boundaries. Under this option, no waste will be removed from the adjacent properties and a small amount of waste may remain at the property line due to soil sloughing. However, if an adjacent property owner agrees, waste removal will “feather” from the buffer zone across the property line. In accordance with the grading plans, (Appendix B), wastes will be removed and “feathered” across the property lines of Lots 6, 7, 8, 9, and 10 a distance of approximately 1 to

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024 11 5 feet beyond the property lines. In addition, soil and waste that was illegally dumped adjacent to Lot 9 will be removed to bedrock, as possible (Appendix B, Section Cut 6/4.2). Following the completion of waste removal, final grading will consist of backfilling with clean import soil to provide positive drainage. In addition, one foot of clean imported soil will be placed on top of the existing cap area (Figure 3, Appendix B). Final grading plans and drainage details are provided in Appendix B.

6.8 Waste Disposition – Reconsolidation
Based on the grading plans in Appendix B, approximately 670 cubic yards (cy) of waste including soil, waste, and grass and roots from grading operations will be excavated and reconsolidated on site. The proposed reconsolidation area on Parcel A is shown on Figure 3 and reconsolidation grading and cover plans are provided on the plans in Appendix B. The excavated waste will be moved to the approved reconsolidation location by the excavation contractor and will be transported in such a manner as to minimize the potential of spillage and creation of dust during transportation. Excavated waste may be first placed in temporary stockpiles near the excavation areas prior to being placed in the reconsolidation area. Temporary stockpiles will be managed in accordance with Section 6.11. Reconsolidated waste will be placed directly on top of the existing waste cap in the reconsolidation area, thereby not intruding into, or disturbing the existing cap, and covered daily with Visqueen plastic or equivalent. The final cover of the reconsolidated waste will consist of at least 2 feet of imported clean soils. Previous dump closure plans and State Regulations do not preclude onsite reconsolidation on top of the current cap.

6.9 Waste Disposition – Neighboring Property Waste Reconsolidation Option
The City is in discussions with the neighboring property owners regarding waste removal from their properties and reconsolidation of the waste on the City property. If this remedial action is agreed upon by the city and property owner(s), waste from the neighboring properties will be placed in temporary stockpiles in designated areas on the City property by the neighboring property owner’s contractor. The property owner contractor(s) will need to meet the requirements specified in this plan including, but not limited to appropriate licensing to handle wastes, adhering to the site and community health and safety plans, etc. Temporary stockpiles will be managed in accordance with Section 6.11 of this plan. The stockpiles will be moved to the site reconsolidation area shown in Figure 4 by the City’s contractor and graded in accordance with the grading plans in Appendix F. Based on the grading plans, if property owners of Lots 6 through 8 and Lot 10 were to select this option, then as estimated by others, approximately 2,753 cy of waste may be

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024 12 reconsolidated from the neighboring residences and from the City owned property. Similar to waste reconsolidation from the City’s property described in Section 6.8, reconsolidated waste from the neighboring properties will be placed directly on top of the existing waste cap in the reconsolidation area and covered with a minimum of two feet of clean imported soil.

6.10 Waste Disposition – Offsite Disposal
As an alternative and at the discretion of the City, excavated waste may be temporally stockpiled, sampled for waste characterization, and transported to an offsite waste facility as described in sections below. The grading plan for this alternative is shown on drawing 5.3 in Appendix B.

6.11 Temporary Stockpiling and Management
Waste may be temporarily stockpiled prior placing waste in the reconsolidation area and/or for offsite waste disposal. As applicable, a staging area and temporary stockpiles will be managed by the Contractor in accordance with this document, construction specifications, and the project SWPPP. Temporary stockpiled waste at the site be managed as follows:
• Place the excavated/stockpiled waste onto 10-millimeter (mil) or thicker visqueen plastic sheeting.
• Temporary stockpiles will be sprayed or misted with water to minimize dust emissions during stockpiling, if necessary.
• Temporary stockpiles will be securely covered daily with a 6-mil or thicker visqueen plastic sheeting to minimize runoff from rain.
• Temporary stockpiles will be configured in such a manner that surface water runoff, if present, from the stockpile does not carry stockpiled materials beyond the stockpile area.

6.11.1 Stockpile Sampling and Characterization for Offsite Disposal Stockpiles intended for offsite disposal will be sampled by running a random number generator to obtain sample locations and depths. If the sampling depth is relatively shallow, the sample will be collected by coring the laboratory-supplied container directly into the material to be sampled. If the sample depth is greater, and depending on the actual volume of the stockpile, excavation equipment and/or hand auger equipment will be used to obtain samples. If excavation equipment is used, the sample will be similarly collected by coring the sample jar directly into the material to be sampled. If hand auger equipment is used then the sample in the auger will be transferred to a laboratory-supplied jar. Analytical testing for wastes to be disposed of offsite will be based on the accepting disposal facility(s)

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024 13 requirements. The contractor should assume the wastes may be tested for chemicals of concern including the following:
• California Title 22 metals; samples containing one or more metal concentrations less than the California Total Threshold Limit Concentrations (TTLCs) but greater than 10-times the California Soluble Threshold Limit Concentrations (STLCs) will be additionally analyzed for soluble metal concentrations by the California Waste Extraction Test (WET) method to profile the waste as either California Class I hazardous or California Class II non-hazardous. Samples containing one or more metal concentrations exceeding 20-times the Federal Toxicity Characteristics Leaching Procedure (TCLP) will be additionally analyzed for soluble metal concentrations by the Federal TCLP to classify the waste as either RCRA or non-RCRA hazardous waste.
• Total Petroleum Hydrocarbon compounds (e.g. TPHgas, TPHdiesesl and TPHmotor oil).

Additional analysis may be required by the disposal facility. In general, the number of discrete samples required is listed below. The actual number of samples to be collected and analyzed will depend on the receiving facilities requirements.
• Stockpiles 100 cy or less -a minimum of four discrete samples will be collected, one from each quarter of the stockpile.
• Stockpile from 101-500 cy - a minimum of one sample from each 25 cy, or portion thereof, will be collected (e.g., a 130-cy stockpile would require six samples). • Stockpile over 500 cy - sample as per a 500 cy stockpile and collect an additional sample for each additional 500 cy, or portion thereof.

6.12 Imported Fill Soil
Clean imported fill soil to be used to cover/cap waste will be sampled and the analytical data, soil classification, and the origin/location of the import soil will be provided to the LEA for approval prior to use onsite. Import fill soil sampling methodology and analysis will follow the California Department of Toxic Substance Control (DTSC) 2001 Information Advisory (for) Clean Imported Fill guidelines (Appendix E). According to DTSC’s guidelines, the number of soil samples is based on the volume of imported fill and summarized below.
• One sample per every 250 cy for up to 1,000 cy.
• Four samples for the first 1,000 cy plus one extra sample per each additional 500 cy. • For a volume of soil greater than 5,000 cy, 12 samples collected for the first 5,000 cy, and one extra sample for every additional 1,000 cy.

The City of Napa estimated that approximately 4,400 cy of soil will be imported which would require approximately nine discrete soil samples for analysis prior to importing to the site. Only

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024 14 discrete samples will be collected because of the potential dilution of contaminants. The samples will be analyzed for Constituents of Potential Concern (COPC) based on the source of the import soil in accordance with the DTSC’s guidelines. The sample results will be compared to DTSC Screening Levels and United States Environmental Protection Agency (EPA) Regional Screening Levels for comparison to human health protection evaluation.

6.13 Best Management Practices
The Contractor shall implement BMPs associated with the site SWPPP to protect the temporary stockpiles from erosion and storm water run-on and runoff. The BMPs include, but are not limited to, the following:
• Erosion control
• Storm water drainage control
• Secondary containment (as applicable)
• Fugitive emission control of dust and/or vapors
• Spill prevention
• Additional BMPs specified in the project SWPPP

6.14 Excavation Sampling
Excavation confirmation sampling is not included in this RAP. The purpose of the excavation is to remove waste within the buffer zone to bedrock and/or cap waste with two feet of clean imported soil so that no waste is exposed at the site. The City of Napa is not proposing clean closure of the dump; therefore, excavation confirmation sampling is not required.

6.15 Field Documentation
Field logs will be kept to document the field activities. Photographs will be taken to document the remedial action activities at active waste removal locations, to verify adequacy of reconsolidated material, placement of cap, temporary “waste” stockpiles and disposed waste removal (as applicable), and to generally document the remedial activities. The photographs will serve to complement information entered in the field activity logs.

6.16 Dust Control and Air Monitoring Plan
Air monitoring and dust control onsite will comply with the SHSP and CHSP (Appendix D and E).

Dust control will include dust suppression activities, such as lightly spraying or misting at active

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024 15 backhoe/track hoe excavation areas and reducing vehicle speed onsite. If waste is temporarily stockpiled for offsite disposal, dust suppression activities will include light spraying or misting the stockpiled materials, covering stockpiles, and minimizing the waste drop height from the excavator’s bucket onto the stockpile or into the transport trucks. Prior to conducting the removal activities, the prevailing wind direction will be determined by obtaining prevailing wind direction information prior to and during field activities.

Per the CHSP, perimeter dust monitoring will be conducted using Thermo DataRAM particulate monitors (pDRs) (or equivalent) to monitor the upwind and downwind particulate levels of the site.

The particulate monitors continuously monitor and record the real-time concentration and median particle size of airborne dust, smoke, mist, and fumes. Personnel will monitor dust during excavation activities. Air monitoring details and action levels are provided in Section 8 of the SHSP (Appendix D) and Section 6 in the CHSP (Appendix E).

6.17 Site Restoration
Site restoration as an open space area will be consistent with the grading plans included in Appendix B. The disturbed soil within capped area with be covered with an additional one foot of clean imported soil and seeded with native grasses. Final restoration will provide positive drainage for the site.
7 LIMITATIONS
The environmental services described in this report have been conducted in general accordance with current regulatory guidelines and the standard-of-care exercised by environmental consultants performing similar work in the project area. No warranty, expressed or implied, is made regarding the professional opinions presented in this report. Variations in Site conditions may exist and conditions not observed or described in this report may be encountered during subsequent activities. Please also note that this study did not include an evaluation of geotechnical conditions or potential geologic hazards.

Ninyo & Moore's opinions and recommendations regarding environmental conditions, as presented in this report, are based on limited subsurface assessment and chemical analysis.

Further assessment of potential adverse environmental impacts from past on-site and/or nearby use of hazardous materials may be accomplished by a more comprehensive assessment. The samples collected and used for testing, and the observations made, are believed to be representative of the area(s) evaluated; however, conditions can vary significantly between

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024 16 sampling locations. Variations in soil and/or groundwater conditions will exist beyond the points explored in this evaluation.

The environmental interpretations and opinions contained in this report are based on the results of laboratory tests and analyses intended to detect the presence and concentration of specific chemical or physical constituents in samples collected from the subject site. The testing and analyses have been conducted by an independent laboratory which is certified by the State of California to conduct such tests. Ninyo & Moore has no involvement in, or control over, such testing and analysis. Ninyo & Moore, therefore, disclaims responsibility for any inaccuracy in such laboratory results.

Our conclusions, recommendations, and opinions are based on an analysis of the observed Site conditions. It should be understood that the conditions of a site could change with time as a result of natural processes or human activities at the subject site or nearby sites. In addition, changes to the applicable laws, regulations, codes, and standards of practice may occur due to government action or the broadening of knowledge. The findings of this report may, therefore, be invalidated over time, in part or in whole, by changes over which Ninyo & Moore has no control.

This document is intended to be used only in its entirety. No portion of the document, by itself, is designed to completely represent any aspect of the project described herein. Ninyo & Moore should be contacted if the reader requires any additional information, or has questions regarding content, interpretations presented, or completeness of this document.

This report is intended exclusively for use by the client. Any use or reuse of the findings, conclusions, and/or recommendations of this report by parties other than the client is undertaken at said parties’ sole risk.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024 17 8 REFERENCES
Engeo, 1988, Geotechnical Exploration, Hidden Glenn – Fennell Property, Napa, California: dated March 2.

Kunkel, F., and Upson, 1960, Geology and Groundwater in the Napa and Sonoma Valley areas.

U.S.G.S. Water Supply Paper 1495.

Langan, 2019a, Field Investigation – Former Hidden Glen Landfill, Lot-6 Glory Court, Napa, California: dated April 29.

Langan, 2019b, Field Investigation – Former Hidden Glen Landfill, Lot-9-Pascal Place, Napa, California: dated April 29.

Langan, 2019c, Field Investigation – Former Hidden Glen Landfill, Lot 7 and 8- Glory Court and Pascal Place, Napa, California: dated April 29.

Langan, 2019d, Field Investigation – Former Hidden Glen Landfill, Lot 10-Pascal Place, Napa, California: dated April 29.

Langan, 2019e, Field Investigation – Former Hidden Glen Landfill, Lot A-Pascal Place, Napa, California: dated April 29.

McClaren-Hart, Inc, 2000, Closure Plan Hidden Glen Landfill, Napa, California: dated April 6.

SCS Engineers, 2020, Property Management Plan for City-Owned Parcel (APN 045-411-022- 000), Investigation and Clean-Up of Closed Hidden Glen Landfill, Napa, California: dated March 2.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024

FIGURES

" SITE
1_109558001_SL.mxd 9/3/2024 JDL
NOTE: DIRECTIONS, DIMENSIONS AND LOCATIONS ARE APPROXIMATE. | SOURCE: ESRI WORLD TOPO, 2024

SITE LOCATION
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FEET
FIGURE 1
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UV128
UV29
UV12
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MAP INDEX
Napa
County
109558001 | 10/24

HIDDEN GLEN DUMP

COOMBSVILLE ROAD, NAPA, CALIFORNIA
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@?& LANDFILL GAS WELL (SCS ENGINEERS, 2020)
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2_109558001_SP.mxd 9/3/2024 JDL NOTE: DIRECTIONS, DIMENSIONS AND LOCATIONS ARE APPROXIMATE. | SOURCES: SITE PLAN - SCS ENGINEERS, DATED: 2-26-20; TOPO - NOAA/USGS LIDARNOAA LIDAR, 2018-2019, NORTHERN CALIFORNIA WILDFIRE-QL2; GOOGLE EARTH, 2024

HIDDEN GLEN DUMP

COOMBSVILLE ROAD, NAPA, CALIFORNIA
109558001 | 10/24
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SITE PLAN
FIGURE 2
050 100
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FLAG

SECTION
LOT 6
LOT 5
LOT 9
LOT 10
LOT 11
LOT 12
LOT 13

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PARCEL A BOUNDARY APN: 045-411-022-000(SCS ENGINEERS, 2020) @
@

PARCEL BOUNDARYAPPROXIMATE LIMIT OF CAP
ADAPTED FROM LANGAN (2018)
LOT 7
LOT 8
APPROXIMATE "BUFFER ZONE"

ASSUMED TO BE THE AREA

BETWEEN THE WASTE CAP

AND ADJACENT RESIDENTIAL

PROPERTIES / LOTS
"
APPROXIMATE "BUFFER ZONE"

ASSUMED TO BE THE AREA

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135
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MW-3
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LEGEND
LANDFILL GAS WELL (SCS ENGINEERS, 2020)
MW-3
3_109558001_PRA.mxd 10/15/2024 JDL
NOTE: DIRECTIONS, DIMENSIONS AND LOCATIONS ARE APPROXIMATE. | SOURCES: GRADING PLAN - CITY OF NAPA, DATED: MARCH 21, 2024; TOPO - NOAA/USGS LIDARNOAA LIDAR, 2018-2019, NORTHERN CALIFORNIA WILDFIRE-QL2; GOOGLE EARTH, 2024

HIDDEN GLEN DUMP

COOMBSVILLE ROAD, NAPA, CALIFORNIA
109558001 | 10/24

PLANNED REMEDIAL ACTION
FIGURE 3
050 100
FEET

2 FOOT SOIL CAP OVER RECONSOLIDATED WASTE
1’-0" SOIL COVER OVER EXISTING CAP

SOIL FILL FOR DRAINAGE

RELOCATED WASTE
(APPROXIMATE WASTE STOCKPILE = 495 CY)
WASTE REMOVAL (<10")
WASTE REMOVAL (10" - 20")

CALLANDER ASSOCIATES LANDSCAPE ARCHITECTURE,
(OCTOBER, 2024)
PARCEL A BOUNDARY APN: 045-411-022-000

PARCEL BOUNDARY

PASCALE PLACE
FLAG

SECTION
LOT 8
LOT 7
LOT 5
LOT 9
LOT 10
LOT 11
LOT 12
LOT 13

GLORY COURT

APPROXIMATE LIMIT OF CAP
ADAPTED FROM LANGAN (2018)
LOT 6
APPROXIMATE "BUFFER ZONE"

ASSUMED TO BE THE AREA

BETWEEN THE WASTE CAP

AND ADJACENT RESIDENTIAL

PROPERTIES / LOTS
APPROXIMATE "BUFFER ZONE"

ASSUMED TO BE THE AREA

BETWEEN THE WASTE CAP

AND ADJACENT RESIDENTIAL

PROPERTIES / LOTS

VERTICAL CLIFF

NO WASTE REMOVAL

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185
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105
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MW-3
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4_109558001_OSWAlt.mxd 10/14/2024 JDL
NOTE: DIRECTIONS, DIMENSIONS AND LOCATIONS ARE APPROXIMATE. | SOURCES: GRADING PLAN - CITY OF NAPA, DATED: MARCH 21, 2024; TOPO - NOAA/USGS LIDARNOAA LIDAR, 2018-2019, NORTHERN CALIFORNIA WILDFIRE-QL2; GOOGLE EARTH, 2024

HIDDEN GLEN DUMP

COOMBSVILLE ROAD, NAPA, CALIFORNIA
109558001 | 10/24

PLANNED REMEDIAL ACTION - OFFSITE WASTE GRADING OPTION
FIGURE 4
050 100
FEET

PARCEL A BOUNDARY APN: 045-411-022-000

PARCEL BOUNDARY

PASCALE PLACE
FLAG

SECTION
LOT 8
LOT 7
LOT 5
LOT 9
LOT 10
LOT 11
LOT 12
LOT 13

GLORY COURT
LOT 6
APPROXIMATE "BUFFER ZONE"

ASSUMED TO BE THE AREA

BETWEEN THE WASTE CAP

AND ADJACENT RESIDENTIAL

PROPERTIES / LOTS
APPROXIMATE "BUFFER ZONE"

ASSUMED TO BE THE AREA

BETWEEN THE WASTE CAP

AND ADJACENT RESIDENTIAL

PROPERTIES / LOTS

VERTICAL CLIFF

NO WASTE REMOVAL

EAST OF CLIFF

CALLANDER ASSOCIATES LANDSCAPE ARCHITECTURE,
(OCTOBER, 2024)

APPROXIMATE LIMIT OF CAP
ADAPTED FROM LANGAN (2018)

RELOCATED WASTE
(APPROXIMATE WASTE STOCKPILE = 2,700 CY)
SOIL TOP COVER < 4’
SOIL TOP COVER 4-5’
SOIL TOP COVER 5-6’
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Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024

APPENDIX A
Closed Disposal Site Inspection Report Hidden Glen Dump 4/23/24

Inspection Information
Inspected By: Napa County Local Inspection ID:

Inspection Date: 4/23/2024 Time In: 8:30 AM
Inspection Type: Periodic Time Out: 9:30 AM
Inspector: Peter Ex Inspection Duration: 1.0
Operator:

Received By:

Also Present (Name):

Facility/Activity Information
Enforcement Agency: County of Napa SWIS Number: 28-AA-0028 Facility: Hidden Glen Dump
Coombsville Rd.

Napa, CA 99999
Activity: Solid Waste Disposal Site
Operational Status: Closed Regulatory Status: Unpermitted Land Owners(s):

The above facility was inspected for compliance with applicable sections of Division 30 of the Public Resources Code (PRC) and Title 14 and Title 27, California Code of Regulations (CCR).

No Violations
No Areas of Concern
Inspection Report Comments
City of Napa Property - No changes observed, however, soil and debris has been illegally disposed on the west side of the property from the Dayan property. See notes below.

Dayan Property - Ms. Dayan has proceeded with further grading and landscaping development of her property despite an agreement in principle via submittal of a Work Plan.

New plants and soil/mulch was observed in the front yard. Ms. Dayan has additionally illegally disposed of the soil previously stockpiled on her property onto the adjacent City of Napa property. Access of machinery was observed to have gone through the adjacent Anderson property as evidenced by recent vegetation disturbance by equipment tracks.

Closed Disposal Site Inspection Report (188)
Hidden Glen Dump (28-AA-0028)
4/23/2024
CalRecycle Solid Waste Information System (SWIS) Page 1 of 2 Date Generated: May 22, 2024 9:46 AM

LEA had intended to provide comments to the Work Plan submitted by Ms. Dayan with the understanding that no further work would continue until the Work Plan was approved by LEA.

City of Napa staff was notified of the illegally dumped material on their property.

Numerous photos were taken with a few attached to this report.

Attachments
Dayan - Back Yard Illegal Dumping 4-23-24
Dayan - Back Yard w Art Turf Install 4-23-24
Dayan - Front Yard 4-23-24
Closed Disposal Site Inspection Report (188)
Hidden Glen Dump (28-AA-0028)
4/23/2024
CalRecycle Solid Waste Information System (SWIS) Page 2 of 2 Date Generated: May 22, 2024 9:46 AM

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024

APPENDIX B
Architect Grading Plans

NONE
1 NONE

SHEET INDEX
NO. DESCRIPTION

1.0 COVER SHEET

1.1 COVER SHEET - NOTES

2.0 DEMOLITION PLAN

3.0 - 3.2 EROSION CONTROL PLAN

4.0 - 4.2 WASTE EXCAVATION PLAN AND SECTIONS

5.0 - 5.3 GRADING PLAN AND SECTIONS

6.0 CONSTRUCTION DETAILS

7.0 TOPOGRAPHIC SURVEY

PREPARED BY

LANDSCAPE ARCHITECT
Callander Associates Landscape
Architecture, Inc.
12150 Tributary Point Drive, Suite 140
Gold River, CA 95670
Phone: (916) 985-4366

PREPARED FOR

CITY OF NAPA
Utilities Department
1700 Second Street, Suite 100
Napa, CA 94559
NO.

REVISIONS

DESCRIPTION
DESCRIPTION:

ELEV.

BENCH MARK

DATE BY

PLANS PREPARED UNDER
THE DIRECTION OF _______________________________ ________ HORIZ.

SCALE OR SONOMA HWY 121
HIGHWAY 29 TO YOUNTVILLE

TO YOUNTVILLE
IMOLA AVE.

FIRST AVE.

HAGEN RD.

SILVERADO TRAIL
HILLCREST DR.

HARDMAN AVE. ATLAS PEAK RD. WESTGATE DR.

TULOCAY CREEK

SALVADOR DRAINAGE CHANNEL
ST.

WAY
NAPA

CABOT WAY
IMOLA AVE.

FOSTER RD. FOOTHILL BLVD.

BIG RANCH RD.

SARCO CREEK MILLIKEN CREEK
MAGNOLIA DR.

SOSCOL AVE.

SPRUCE ST.

COOMBS ST.

PEARL ST.

BROWN
YAJOME ST.

IMPERIAL WAY
EAST FIRST ST.

LINCOLN AVE.

TRANCAS ST.

CALISTOGA
PINE ST.

SECOND ST. FIRST ST.

LAUREL ST.

KILBURN AVE.

CREEK
NAPA
PARTRICK RD. LONE OAK AVE.

REDWOOD
BROWNS VALLEY RD.

REDWOOD RD.

OXFORD ST.

JEFFERSON ST.

EL CENTRO AVE.

TROWER AVE.

LINDA VISTA AVE.

WINE COUNTRY AVE. EL CENTRO AVE.

SALVADOR AVE.

ORCHARD AVE.

CREEKAUSTIN WAY

PROJECT SITE
N T:\Projects\2017 Projects\17058_HiddenGlenPark\3_ConstructionDocuments\A17058_CV.dwg DRAWN BY:

DESIGNED BY:

CHECKED BY:

DATE
DATE
DATE

CITY OF NAPA

DEPARTMENT

HIDDEN GLEN DUMP REMEDIATION
CITY PROJECT NO. C2023-083

1.0 SHEET NO.

DRAWING NO.

CAD FILE:

DATE:

OF

TO CALISTOGA

TROWER AVENUE

TO SACRAMENTO

CORDELIA

TO SAN FRANCISCO

CITY OF

AMERICAN CANYON

TO SONOMA

IMOLA AVENUE

FIRST STREET

APPROVED

APPROVAL RECOMMENDED
VERT.

RH/OP
BS
MR
5/22/24

PASCALE PLACE SOSCOL AVENUE

EXISTING CONDITIONS LEGEND
FENCE

PROPERTY LINE

APPROXIMATE LIMITS OF LANDFILL CAP

FLOWLINE OF ROCK SWALE

WATER LINE

SANITARY SEWER LINE

ELECTRICAL LINE

AT&T COMMUNICATION LIINE

DRAIN INLET

WATER VALVE

WATER METER
TREE

SEWER CLEANOUT
CONTOUR, 1'-0" INTERVALS
NO.

REVISIONS

DESCRIPTION
DESCRIPTION:

ELEV.

BENCH MARK
Melissa Ruth, No. 5425 DATE

PLANS PREPARED UNDER
THE DIRECTION OF _______________________________ ________

TO SONOMA

CONGRESS VALLEY RD TO VALLEJO

NAPA RIVER
HIGHWAY 121
RIVER
NAPA SHURTLEFF AVE. TERRACE DR COOMBSVILLE RD.

VICHY RD.

MONTICELLO RD.

CENTRAL AVE.

C ST.

YORKST.

LAUREL ST. COLLEGE
STREBLOW DR.

OLD SONOMA RD. PATTON AVE. TERRACE DR. SHETLER
KANSAS AVE.

SOUZA LN.

FRANKLIN ST.

VALLEJO ST. HAYES ST.

JEFFERSON ST.

MAIN ST.

JUAREZ ST.

SILVERADO TRAIL EAST AVE.

CALIFORNIA BLVD. PUEBLO AVE.

THIRD ST.

FREEWAY DR.

AVE.

THOMPSON
BUHMAN AVE. BROWNS VALLEY RD.

CREEK
WEST PUEBLO AVE.

YOUNG AVE.

VINE HILL DR. PINOT ST. DRY CREEK RD.

MAHER ST.

SOLANO AVE. SOSCOL AVE.

AVE.

BROWNS VALLEY
SOLANO AVE.

N

SITE MAP

NOT TO SCALE
15 T:\Projects\2017 Projects\17058_HiddenGlenPark\3_ConstructionDocuments\A17058_CV.dwg OCTOBER 14, 2024
SHEET NO.

DRAWING NO.

CAD FILE:

DATE:

OF

SALVADOR AVENUE

TRANCAS STREET REDWOOD ROAD

LINCOLN AVENUE
NAPA

AREA MAP

NOT TO SCALE

PROJECT AREA

TO VALLEJO

JAMESON

CANYON ROAD

AMERICAN CANYON ROAD
10/14/24
5/22/24
A17058_CV.dwg

COOMBSVILLE
ROAD
5/22/24
TOTAL PROJECT AREA: 1.66 ACRES
TOTAL SITE DISTURBANCE: 1.60 ACRES
PERMIT REQUIREMENTS:
- CONSTRUCTION GENERAL PERMIT (SWPPP)
Know what'sbelow.

Call before you dig.

R HIDDEN GLEN DUMP REMEDIATION

TITLE SHEET
'29 ' 121 '
• 21 50 Tri':iutary r'oint IJ'i'~o, Suite 11:l
Gol,d Ritter Cl\ 9~J6
I 916,985/1365

UTILITIES
\
----~---,;,-~- ~
I
'
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UTILITIES DEPARTMENT
-x-
--55--
1111
coe
--120--

NONE
2 NONE
NO.

REVISIONS

DESCRIPTION
DESCRIPTION:

ELEV.

BENCH MARK

DATE BY

PLANS PREPARED UNDER
THE DIRECTION OF _______________________________ ________ HORIZ.

SCALE T:\Projects\2017 Projects\17058_HiddenGlenPark\3_ConstructionDocuments\A17058_CV.dwg DRAWN BY:

DESIGNED BY:

CHECKED BY:

DATE
DATE
DATE

HIDDEN GLEN DUMP REMEDIATION

TITLE SHEET - NOTES

1.1 SHEET NO.

DRAWING NO.

CAD FILE:

DATE:

OF
VERT.

RH/OP
BS
MR
NO.

REVISIONS

DESCRIPTION
DESCRIPTION:

ELEV.

BENCH MARK
Melissa Ruth, No. 5425 DATE

PLANS PREPARED UNDER
THE DIRECTION OF _______________________________ ________ 14 T:\Projects\2017 Projects\17058_HiddenGlenPark\3_ConstructionDocuments\A17058_CV.dwg SHEET NO.

DRAWING NO.

CAD FILE:

DATE:

OF
A17058_CV.dwg
Know what'sbelow.

Call before you dig.

R

1. DESIGN INTENT: THESE DRAWINGS REPRESENT THE GENERAL DESIGN INTENT TO BE IMPLEMENTED ON THE SITE. CONTRACTOR SHALL BE RESPONSIBLE FOR

CONTACTING OWNER'S REPRESENTATIVE FOR ANY ADDITIONAL

CLARIFICATION OR DETAILS NECESSARY TO ACCOMMODATE SITE
CONDITIONS.

2. CONTRACTOR COORDINATION: EACH CONTRACTOR SHALL COORDINATE

AND OTHERWISE INTEGRATE WORK WITH THAT OF OTHERS IN AN EFFICIENT

AND TIMELY MANNER SO AS TO PROVIDE THE OWNER WITH A
WELL-CONSTRUCTED, EASILY MAINTAINABLE PROJECT. EACH CONTRACTOR

SHALL NOTIFY OTHERS AT LEAST TWO WORKING DAYS IN ADVANCE OF COVERING, COMPLETING, OR EXPOSING WORK TO BE INSTALLED BY OTHERS.

3. CONTRACTORS' JOB SITE CONDITIONS: CONTRACTOR AGREES TO ASSUME

SOLE AND COMPLETE RESPONSIBILITY FOR SITE CONDITIONS DURING CONSTRUCTION, INCLUDING SAFETY OF ALL PERSONS AND PROPERTY; THAT

THIS REQUIREMENT SHALL APPLY CONTINUOUSLY AND NOT BE LIMITED TO NORMAL WORKING HOURS; AND THAT THE CONTRACTOR SHALL DEFEND,

INDEMNIFY, AND HOLD THE OWNER AND THE LANDSCAPE ARCHITECT

HARMLESS FROM ANY AND ALL LIABILITY, REAL OR ALLEGED, IN

CONNECTION WITH THE PERFORMANCE OF WORK ON THIS PROJECT,

EXCEPTING FOR LIABILITY ARISING FROM THE SOLE NEGLIGENCE OF THE OWNER OR THE LANDSCAPE ARCHITECT.

4. COMPOSITE BASE SHEET: THE PROPOSED IMPROVEMENTS SHOWN ON THESE DRAWINGS ARE SUPERIMPOSED ON A BASE SHEET. THIS BASE SHEET IS

COMPILED FROM THE TOPOGRAPHIC SURVEY, OTHER ARCHITECTURAL

AND/OR ENGINEERING DOCUMENTS, AND OTHER DATA AS MADE
AVAILABLE TO THE LANDSCAPE ARCHITECT. THIS BASE SHEET INFORMATION IS SHOWN IN HALF TONE ON THE PLANS. THE LANDSCAPE ARCHITECT SHALL

NOT BE HELD LIABLE FOR CHANGES, INACCURACIES, OMISSIONS, OR OTHER ERRORS ON THESE DOCUMENTS. THE COMPOSITE BASE SHEET IS PROVIDED AS

AN AID ONLY AND THE CONTRACTOR SHALL BE RESPONSIBLE FOR

REVIEWING THESE DOCUMENTS AND INCORPORATING/INTEGRATING ALL CONSTRUCTION AS REQUIRED TO ACCOMMODATE SAME.

THE BASE SHEET SOURCE FOR THESE DRAWINGS IS:

TOPOGRAPHIC MAP OF HIDDEN GLEN PARK, SUBDIVISION PARCEL "A", SHEET 1, APN: 045-411-022-000, PREPARED BY CHAUDHARY & ASSOCIATES, INC., AUGUST 1ST 2023, (707)255-2729

5. UTILITIES: PRIOR TO CONSTRUCTION, THE CONTRACTOR IS RESPONSIBLE FOR

CONTACTING THE UTILITY COMPANIES INVOLVED AND REQUESTING A VISUAL VERIFICATION OF THE LOCATIONS OF THEIR UNDERGROUND FACILITIES. THE

UTILITY COMPANIES ARE MEMBERS OF THE UNDERGROUND SERVICE ALERT (U.S.A.) ON-CALL PROGRAM. THE CONTRACTOR OR ANY SUBCONTRACTOR FOR THIS CONTRACT SHALL NOTIFY MEMBERS OF THE U.S.A. 48 HOURS IN

ADVANCE OF PERFORMING EXCAVATION WORK BY CALLING THE TOLL-FREE NUMBER 811. EXCAVATION IS DEFINED AS BEING 18 OR MORE INCHES IN DEPTH BELOW THE EXISTING SURFACE.

THE CONTRACTOR IS CAUTIONED THAT ONLY EXCAVATION WILL REVEAL THE

TYPES, EXTENT, SIZES, LOCATION, AND DEPTHS OF SUCH UNDERGROUND UTILITIES. HOWEVER, THE LANDSCAPE ARCHITECT CAN ASSUME NO

RESPONSIBILITY FOR THE COMPLETENESS OR ACCURACY OF ITS DELINEATION

OF SUCH UNDERGROUND UTILITIES, NOR FOR THE EXISTENCE OF OTHER BURIED OBJECTS OR UTILITIES WHICH ARE NOT SHOWN ON THESE DRAWINGS.

6. TREE PROTECTION AND MAINTENANCE REQUIREMENTS: ALL TRENCHING

WITHIN THE DRIPLINE OF EXISTING TREES TO REMAIN SHALL BE BY HAND, WITH CARE TAKEN NOT TO CUT OR DAMAGE ROOTS OVER 1-INCH DIAMETER.

TREES TO REMAIN SHALL BE FENCED WITH TEMPORARY FENCING, SUCH AS STEEL STAKES (MAX. 5 FEET O.C.) WITH WIRE MESH FABRIC (6X6 OPEN), CHAINLINK, OR SIMILAR, HEIGHT TO BE 5 FEET MINIMUM.

GENERAL NOTES

1. ALL WORKMANSHIP AND MATERIALS FOR BOTH ON-SITE AND OFF-SITE

IMPROVEMENTS SHALL CONFORM TO THE MOST RECENT EDITION OF THE CITY OF NAPA STANDARD SPECIFICATIONS AND ADDENDUMS, AND/OR THE 2015 EDITION

OF THE STATE OF CALIFORNIA STANDARD SPECIFICATIONS, STANDARD PLANS, AND THE GEOTECHNICAL REPORT AND ALL THE NOTES SHOWN. THE CONTRACTOR SHALL HAVE A COPY OF ALL DOCUMENTS AVAILABLE AT THE JOB SITE AT ALL TIMES.

ALL ON SITE IMPROVEMENTS SHALL BE INSPECTED AND CERTIFIED BY THE ENGINEER OF RECORD. IMPROVEMENTS IN THE PUBLIC RIGHT OF WAY SHALL BE INSPECTED BY THE CITY OF NAPA.

2. THE CONTRACTOR SHALL CONTACT THE UTILITIES DEPARTMENT AT 707-257-9521 TO

SCHEDULE A PRECONSTRUCTION MEETING PRIOR TO THE COMMENCEMENT OF ANY AND ALL WORK. DURING THE DURATION OF THE PROJECT, ROLLING 3-WEEK LOOK AHEAD SCHEDULES WILL BE REQUIRED TO BE SUBMITTED WEEKLY.

3. THE CONTRACTOR AND ALL SUBCONTRACTORS MUST CALL UNDERGROUND SERVICE ALERT (USA NORTH 811 OR 1-800-227-2600) PRIOR TO THE START OF ANY WORK ON THE PROJECT SITE. EACH CONTRACTOR SHALL SUBMIT A COPY OF THEIR USA TAG TO THE CITY FOR VERIFICATION. THE CONTRACTOR SHALL ALSO CALL

ANY COMPANY OR AGENCY FOR SERVICE LOCATIONS WHO ARE NOT A MEMBER OF UNDERGROUND SERVICE ALERT. CONTRACTOR SHALL BE RESPONSIBLE FOR THE VERIFICATION OF ALL EXISTING UTILITIES IN THE FIELD. LOCATIONS OF UTILITIES AND

UNDERGROUND FACILITIES SHOWN ARE APPROXIMATE AND FOR GENERAL INFORMATION ONLY. THE CONTRACTOR IS RESPONSIBLE FOR REMOVING U.S.A.

MARKINGS AFTER THE COMPLETION OF CONSTRUCTION FROM THE PUBLIC RIGHT OF WAY.

4. THE CONTRACTOR SHALL COORDINATE ALL NECESSARY UTILITY INSPECTIONS, SCHEDULING AND RELOCATIONS WITH THE APPROPRIATE UTILITY COMPANIES.

5. ALL WORK SHALL BE IN ACCORDANCE WITH THE PREVAILING GOVERNING AGENCY. FOR DISCREPANCIES BETWEEN THESE PLANS AND THOSE AGENCIES' REGULATIONS AND STANDARD PLANS, AGENCY REQUIREMENTS SHALL PREVAIL.

6. THE CONTRACTOR SHALL PROVIDE A MINIMUM OF TWO - 24 HOUR A DAY

EMERGENCY TELEPHONE NUMBERS OF THE PERSON(S) WHO CAN RESPOND TO THE PROJECT.

7. ALL MATERIALS SHALL BE FURNISHED AND INSTALLED BY THE

DEVELOPER/CONTRACTOR UNLESS OTHERWISE NOTED ON THE PLANS OR SPECIFICATIONS.

8. CONTRACTOR SHALL CONFORM TO EXISTING STREETS, SURROUNDING LANDSCAPE

AND OTHER IMPROVEMENTS WITH A SMOOTH TRANSITION IN PAVING, CURBS, GUTTERS, SIDEWALKS, GRADING, ETC., AND TO AVOID ANY ABRUPT OR APPARENT

CHANGES IN GRADES OR CROSS SLOPES, LOW SPOTS OR HAZARDOUS CONDITIONS.

9. FOR ALL CONSTRUCTION ACTIVITIES INCLUDING BUT NOT LIMITED TO: GRADING,

FENCING, RETAINING WALLS, TREE TRIMMING, STORM DRAINAGE, OR ANY OTHER

TYPE OF WORK, THE DEVELOPER/CONTRACTOR SHALL PROVIDE THE CITY A

RIGHT-OF-ENTRY/TEMPORARY CONSTRUCTION EASEMENT SIGNED BY THE OWNER

OF RECORD OF THE AFFECTED/ADJACENT PROPERTY PRIOR TO START OF CONSTRUCTION.

10. THE CONTRACTOR SHALL NOTIFY ALL CUSTOMERS OF SERVICE INTERRUPTIONS 48 HOURS IN ADVANCE WITH DOOR HUNG NOTICES. INTERRUPTION SCHEDULING SHALL BE AUTHORIZED IN WRITING BY WATER DIVISION ENGINEER.

11. CONSTRUCTION ACTIVITIES THROUGHOUT THE ENTIRE DURATION OF THE PROJECT SHALL BE LIMITED TO THE HOURS OF 7:00 A.M. TO 7:00 P.M., MONDAY THROUGH FRIDAY. THERE SHALL BE NO STARTUP OF MACHINES NOR EQUIPMENT PRIOR TO 8:00 A.M., MONDAY THROUGH FRIDAY; NO DELIVERY OF MATERIALS NOR EQUIPMENT PRIOR TO 7:30A.M. NOR PAST 5:00P.M., MONDAY THROUGH FRIDAY; NO CLEANING OF MACHINES NOR EQUIPMENT PAST 6:00 P.M., MONDAY THROUGH FRIDAY; NO SERVICING OF EQUIPMENT PAST 6:45 P.M., MONDAY THROUGH FRIDAY; AND CONSTRUCTION ON WEEKENDS OR LEGAL HOLIDAYS SHALL BE LIMITED TO THE HOURS OF 8:00 A.M. TO 4:00 P.M., UNLESS THE

CONTRACTOR SUBMITS A WRITTEN REQUEST AND THAT REQUEST IS APPROVED BY THE CITY MANAGER, OR THEIR DESIGNEE, PURSUANT TO SECTION 8.08.025 &

8.08.050 OF THE CITY MUNICIPAL CODE. IF THE REQUEST TO WORK OUTSIDE OF THE

DESIGNATED HOURS IS APPROVED, THE CONTRACTOR MAY BE REQUIRED TO PAY

THE COST OF PROVIDING INSPECTION SERVICES FOR THE WORK BEING PERFORMED. IF INSPECTION SERVICES ARE NOT AVAILABLE FOR THE REQUESTED CHANGE, THE CITY ENGINEER MAY DENY THE REQUEST. THE CITY MANAGER, OR DESIGNEE, SHALL GRANT SUCH PERMIT:

A. FOR EMERGENCY WORK;
B. OTHER WORK, IF WORK AND EQUIPMENT WILL NOT CREATE NOISE THAT MAY BE UNREASONABLY OFFENSIVE TO NEIGHBORS AS TO CONSTITUTE A NUISANCE; OR C. IF NECESSARY TO PROTECT THE PUBLIC HEALTH, SAFETY, AND WELFARE.

ALL MUFFLER SYSTEMS ON CONSTRUCTION EQUIPMENT SHALL BE PROPERLY MAINTAINED. ALL CONSTRUCTION EQUIPMENT SHALL NOT BE PLACED ADJACENT

TO DEVELOPED AREAS UNLESS SAID EQUIPMENT IS PROVIDED WITH ACOUSTICAL SHIELDING. ALL CONSTRUCTION AND GRADING EQUIPMENT SHALL BE SHUT DOWN WHEN NOT ACTIVELY IN USE.

IF AN INSPECTOR IS REQUIRED TO BE ONSITE FOR WORK OUTSIDE OF THE MONDAY

THROUGH FRIDAY WORK HOURS, THE CONTRACTOR SHALL REQUEST FROM THE CITY, IN WRITING, 72 HOURS PRIOR TO THE WORK, FOR APPROVAL. IF PRIOR

WRITTEN NOTICE IS NOT PROVIDED, THE REQUEST WILL BE DENIED, AND CONSTRUCTION WORK MAY NOT BE PERFORMED. ADDITIONAL FEES MAY BE CHARGED FOR WORK OUTSIDE OF THE MONDAY THROUGH FRIDAY WORK HOURS.

THE CITY RESERVES THE RIGHT TO DENY ALL WORK OUTSIDE OF THE MONDAY THROUGH FRIDAY WORK HOURS.

DEVELOPER/CONTRACTORS WILL BE GIVEN ONE (1) WARNING FOR WORK STARTING PRIOR TO OR AFTER THE WORK HOURS STATED ABOVE. AFTER THE FIRST

WARNING IS GIVEN, ANY VIOLATIONS OF TIME WILL RESULT IN AN AUTOMATIC FIVE (5) WORKING DAY SHUTDOWN OF THE ENTIRE PROJECT.

NO STAGING OR DELIVERIES IN THE PUBLIC RIGHT OF WAY UNLESS APPROVED PER WRITTEN REQUEST.

THE CITY ENGINEER, PLANNING COMMISSION OR CITY COUNCIL MAY IMPOSE

ADDITIONAL LIMITATIONS ON WORKING HOURS AND NOISE BASED ON THE

SPECIAL CIRCUMSTANCES THAT MAY BE ASSOCIATED WITH A PARTICULAR PROJECT. IN WHICH CASE, THE MORE STRINGENT LIMITATIONS SHALL APPLY.

12. THE CONTRACTOR SHALL BE RESPONSIBLE FOR THE PROTECTION OF ALL EXISTING SURVEY MONUMENTS AND CONTROL POINTS. ALL MONUMENTS DESTROYED

DURING CONSTRUCTION SHALL BE RESURVEYED AND REPLACED BY THE

CONTRACTOR AND AT THE CONTRACTOR'S EXPENSE AS OUTLINED IN THE BUSINESS AND PROFESSIONS CODE, SECTION 8771.

13. THE CONTRACTOR SHALL PROVIDE THE CITY SUBMITTAL(S) FOR ALL MATERIAL TO BE INSTALLED WITHIN THE PUBLIC RIGHT OF WAY ON THE PROJECT. CONSTRUCTION SHALL NOT START PRIOR TO SUBMITTALS BEING APPROVED. PRIOR TO BEING

SUBMITTED TO THE CITY, THE DESIGNER OF RECORD SHALL REVIEW AND APPROVE SUCH RIGHT OF WAY SUBMITTAL.

14. SITE SECURITY, PERIMETER CONTROLS, AND SITE SAFETY ARE THE RESPONSIBILITY OF

THE DEVELOPER/CONTRACTOR AND SHALL BE INSTALLED AND MAINTAINED DURING ALL PHASES OF CONSTRUCTION. TEMPORARY 6FT CHAINLINK FENCING

WITH OPAQUE SCREENING SHALL BE USED FOR SITE SECURITY UNLESS ANOTHER METHOD IS SUBMITTED AND APPROVED FOR USE BY THE CITY.

CITY OF NAPA GENERAL CONSTRUCTION NOTES

RECORD DRAWING
DATE OF COMPLETION:

CONTRACTOR:

ENGINEER:

SURVEYOR:

GEOTECHNICAL:

ENGINEER OF RECORD:

STAMPED AND SIGNED BY:

1. ALL TRAFFIC CONTROL REQUIRED FOR CONSTRUCTION ACTIVITIES SHALL CONFORM TO THE REQUIREMENTS OF THE LATEST EDITION OF CA MUTCD.

FOR ALL LANE CLOSURES AND DETOURS, A TRAFFIC CONTROL PLAN SHALL BE

SUBMITTED TO THE CITY OF NAPA FOR REVIEW AND APPROVAL AT LEAST TEN WORKING DAYS BEFORE THE SCHEDULED CLOSURE. THE CITY WILL REVIEW ALL TRAFFIC CONTROL PLANS. CONSTRUCTION WILL NOT BE ALLOWED TO START PRIOR TO THE APPROVAL OF THE TRAFFIC CONTROL PLAN.

2. ALL TRAFFIC CONTROL PLANS SHALL BE A CAD DRAWING FORMAT PLAN WITH COMPLETE DETAILS AND TABLES. AERIAL PHOTOS, HAND DRAWN PLANS AND NOTES ARE NOT ACCEPTABLE.

3. NO PARKING SIGNS SHALL BE PLACED 48 HOURS PRIOR TO THE WORK TO BE COMPLETED WITHIN AN AREA OF DESIGNATED PUBLIC PARKING. NO

PARKING SIGNS SHALL BE FILLED IN WITH ALL PERTINENT INFORMATION OF THE EXACT TIME THE WORK IS TO TAKE PLACE. SIGNS SHALL BE CLEAR AS TO

WHEN THE PUBLIC MAY PARK IN THE AREA OUTSIDE OF THE CONSTRUCTION TIME. IF WORK IS STAGED OR DELAYED, THEN ALL NO PARKING SIGNS SHALL BE REMOVED AND NEW NO PARKING SIGNS SHALL BE PLACED 48 HOURS PRIOR TO WHEN WORK IS READY TO RESUME.

4. PEDESTRIAN AND BIKE ACCESS THROUGH AND/OR ADJACENT TO THE

PROJECT SITE SHALL REMAIN UNOBSTRUCTED DURING THE PROJECT

CONSTRUCTION OR A DETOUR ROUTE SHALL BE ESTABLISHED AS APPROVED BY THE CITY.

5. THE CONTRACTOR IS REQUIRED TO MAINTAIN ALL TRAFFIC CONTROL

EQUIPMENT IN-PLACE DURING WORK ACTIVITIES AND SHALL REMOVE ALL

TRAFFIC CONTROL THAT IS NOT NEEDED AND RETURN ACCESSIBLE TRAVEL FOR THE PUBLIC DURING NON-WORK HOURS OR DAYS.

6. THE CITY RESERVES THE RIGHT TO STOP ALL WORK BEING PERFORMED FOR

LACK OF TRAFFIC CONTROL OR TRAFFIC CONTROL THAT IS NOT PER THE APPROVED TRAFFIC CONTROL PLAN.

7. THE CONTRACTOR IS REQUIRED TO MAINTAIN ALL TEMPORARY PAVEMENT DELINEATION UNTIL THE PERMANENT PAVEMENT DELINEATION IS PLACED. ALL PERMANENT TRAFFIC STRIPING SHALL BE LAID OUT AND CAT-TRACKED. THE

CITY SHALL HAVE A MINIMUM OF TEN WORKING DAYS TO APPROVE THE STRIPING LAYOUT AND CAT-TRACKING.

TRAFFIC CONTROL NOTES

1. PRIOR TO PROJECT ACCEPTANCE, THE ENGINEER OF

RECORD, THE SURVEYOR OF RECORD, AND THE GEOTECH

OF RECORD SHALL SUBMIT AN ENGINEER'S STAMPED
CERTIFICATION LETTER TO THE CITY.

2. PRIOR TO PROJECT ACCEPTANCE ALL ITEMS ON THE

DEFICIENCY LIST SHALL BE CORRECTED AND SIGNED OFF BY
ALL DIVISIONS.

3. GEOTECH OF RECORD SHALL SUBMIT A FINAL REPORT AND

SUMMARY OF ALL TESTING AND DESIGN CHANGES PRIOR TO
ACCEPTANCE.

4. PRIOR TO PROJECT ACCEPTANCE, ACCURATE "RECORD
DRAWINGS" SHALL BE SUBMITTED TO THE CITY, STAMPED AND
SIGNED WITH THE FOLLOWING:

PROJECT ACCEPTANCE NOTES
5/22/24
10/14/24
5/22/24
5/22/24
OCTOBER 14, 2024
C 21 50 Tri:iutary r'oint IJ'i'~o, Suite 11:l
Gol,d Ritter Cl\ 9~J6
I 916,985/1365

UTILITIES DEPARTMENT
USE CF DOCl.lENTS
A. User acknowledges Callander Associates Landscape Architecture, lnc.'s (Callander Associates) construction documents, lncluclng electronlc flles, reports, plans, specifications, or other construction documents prepared by Callander Associates as Instruments of professlonal service and that these Instruments are Intended only for use on this pro Ject, and not any future phases or for other uses. The User shd not reuse or make any moclflcatlon to the construction documents without the prior written authorization of Callander Associates. In the event the User, the User's contractors or subcontractors, or anyone for whom the User la legally Hable, makes or permits to be made any changes to the construction documents without obtaining Callander Associates' prior written consent, the User shall assume full responslblllty for the results ol such changes.

B. The User agrees, to Indemnity and hold harmless Callander Associates, Its officers, directors, employees and subconsultants (collectlvely Callander Associates) against any damages, llabllltles or costs, lncludlng reasonable attorneys' fees and defense costs, arising from or allegedly arising from or In any way connected with the unauthorized reuse or moclflcatlon of the construction documents by the User, or any person or entity that acquires or obtains the construction documents from or through the User, without the written authorization of Callander Associates.

WPB
SD

SD WPB SL PGE SL
W
W
PGE
PG&E
SL

APPROXIMATE LIMIT
OF LANDFILL CAP.

APPROXIMATE LIMIT
OF LANDFILL CAP.

APPROXIMATE LIMIT
OF LANDFILL CAP.

TEMP. FENCE
TEMP. FENCE

POISON OAKS, SEE
DEMOLITION NOTE #3
1 2 3
4 9
12 12
7 6
12 7
8 10
11 5

1. CLEAR AND GRUB: CONTRACTOR SHALL CLEAR AND GRUB ALL EXISTING VEGETATION, UNLESS OTHERWISE INDICATED, AS REQUIRED FOR THE GRADING, SITE CONSTRUCTION, AND PLANTING OPERATIONS. LIMITS OF CLEARING SHALL BE REVIEWED WITH OWNER PRIOR TO COMMENCEMENT OF WORK. SEE SPECIFICATIONS FOR MORE INFORMATION.

CONTRACTOR SHALL REVIEW DEMOLITION, AND CLEARING AND GRUBBING REQUIREMENTS ON SITE WITH LANDSCAPE ARCHITECT PRIOR TO COMMENCING DEMOLITION OPERATIONS.

ALL DEMOLITION OPERATIONS WITHIN THE DRIP LINE OF TREES SHALL CONFORM TO TREE PROTECTION NOTES AND SPECIFICATIONS.

2. LANDFILL CAP PROTECTION: REFER TO SPECIAL PROVISIONS SECTION 00 72 00 GENERAL REQUIREMENTS, SECTION 1.3.C FOR LANDFILL CAP PROTECTION REQUIREMENTS.

3. REMOVAL OF POISON OAK: CONTRACTOR SHALL NOTIFY ALL WORKERS TO WEAR SPECIFIC PPE GEAR AND USE THE APPROPRIATE TOOLS NEEDED TO REMOVE & DISPOSE OF POISON OAK. MORE INFORMATION ABOUT THE REMOVAL PROCESS IS ON SECTION 22.1.4.2. OF
WWW.PARKS.CA.GOV/PAGES/1324/FILES/CHAPTER%2022%20-%20WORK%20SITE%20SAFETY.FINAL.12.27.18.PDF T.B.R.

DEMOLITION LEGEND

EXISTING TREE TO REMAIN, PROTECT IN PLACE

TREE SIZE (DBH) AND TYPE

EXISTING TREE TO BE REMOVED

TEMPORARY CONSTRUCTION FENCING,

PER SPECS
TREE PROTECTION FENCING, PER SPECS.

REFER TO TREE PROTECTION NOTES FOR
ADDITIONAL REQUIREMENTS.

1. DAMAGES: THE CONTRACTOR SHALL BE HELD LIABLE FOR ANY DAMAGE TO EXISTING TREES, I.E. TRUNK WOUNDS, BROKEN LIMBS, POURING OF ANY DELETERIOUS MATERIALS, OR CONCRETE WASHOUT UNDER THE DRIPLINE OF THE TREES. DAMAGES WILL BE ASSESSED USING THE "GUIDE TO PLANT APPRAISAL" 9TH EDITION, PUBLISHED BY THE INTERNATIONAL SOCIETY OF ARBORICULTURE. AN APPRAISAL REPORT PREPARED BY THE CONTRACTOR'S CERTIFIED ARBORIST SHALL BE SUBMITTED TO THE CITY ARBORIST FOR REVIEW AND APPROVAL.

2. PRIOR TO THE START OF DEMOLITION TREE PROTECTION FENCING PER SPECS SHALL BE INSTALLED A MINIMUM OF ONE FOOT BEYOND THE CANOPY DRIP LINE OF ANY TREE TO REMAIN WHICH WILL BE AFFECTED BY THE PROPOSED WORK. DIMENSIONS WILL BE CONTINGENT UPON THE TREE SIZE AND SPECIES. THE FENCING SHALL REMAIN IN PLACE FOR THE DURATION OF THE PROJECT EXCEPT FOR THE TEMPORARY REMOVAL REQUIRED FOR GRADING OR DEMOLITION OPERATIONS. THIS TREE

PROTECTION ZONE (TPZ) SHALL BE POSTED WITH WARNING SIGNS IN ENGLISH AND SPANISH TO ALERT EQUIPMENT OPERATORS AND CONTRACTORS ABOUT THE PROTECTED STATUS OF THE TPZ. SIGNS SHOULD CONTAIN CONTACT INFORMATION FOR THE CONTRACTOR.

3. THE CONTRACTOR SHALL HIRE AN INTERNATIONAL SOCIETY OF ARBORICULTURE (ISA) CERTIFIED ARBORIST (PROJECT

ARBORIST) AND ALL ARBORICULTRAL AND RELATED SOIL WORK SHALL BE PERFORMED UNDER THE SUPERVISION OF PROJECT ARBORIST OR CITY ENGINEER OR DESIGNATED REPRESENTATIVE. PROJECT ARBORIST SHALL MAKE INSPECTIONS DURING EXCAVATION FOR TEMPORARY CONSTRUCTION ENTRANCE AND AGGREGATE BASE SURFACING. CONTINUED DISCUSSION

AND COORDINATION BETWEEN PROJECT ARBORIST, OWNERS, CONTRACTORS, AND CITY ENGINEER SHALL OCCUR TO FURTHER DEFINE THESE GUIDELINES BASED ON THE ACTUAL WORK PLANNED IN THE VICINITY OF TREES TO REMAIN. ALL

SPECIFIED ARBORICULTURAL WORK SHALL BE COMPLETED PRIOR TO SITE GRADING (HAND TRENCHING, PRUNING, FENCING, ETC.)

4. NO EXCAVATION, GRADE CHANGES, STORAGE OF MATERIALS, OR PARKING OF VEHICLES SHALL BE ALLOWED WITHIN THE TREE PROTECTION FENCE. BORING OR HAND EXCAVATION FOR AGGREGATE BASE, UTILITIES SHALL BE DONE BY THE CONTRACTOR WITHIN THE TREE DRIPLINE AND SHALL BE UNDER THE SUPERVISION OF THE PROJECT ARBORIST. SEE SPECIFICATIONS FOR ADDITIONAL ROOTZONE PROTECTION REQUIREMENTS.

5. IF DURING EXCAVATION A TREE ROOT GREATER THAN 2 INCHES IN DIAMETER IS ENCOUNTERED, THEN ALL WORK SHALL STOP IMMEDIATELY UNTIL PROJECT ARBORIST CAN PERFORM AN ON-SITE INSPECTION. ALL ROOTS SHALL BE CUT CLEAN AND THE TREE AFFECTED MAY REQUIRE SUPPLEMENTAL IRRIGATION/FERTILIZATION AND PRUNING AS A RESULT OF ROOT PRUNING.

6. TREE REMOVAL: REMOVAL OR PRUNING OF ANY PROTECTED NATIVE TREE, SIGNIFICANT TREE OR TREE WITHIN THE PUBLIC

RIGHT-OF-WAY REQUIRES A PERMIT FROM THE CITY OF NAPA PARKS AND RECREATION SERVICES DEPARTMENT UNLESS IT IS APPROVED VIA AUTHORIZED SIGNATURE ON THE DEVELOPMENT PLANS. TREES REMOVED SHALL COMPLETELY REMOVED AND CUT TO GRADE. TREES TO BE REMOVED SHALL BE POSTED 3 DAYS PRIOR INDICATING THAT IT WILL BE REMOVED AND THE REMOVAL HAS BEEN APPROVED AS PART OF AN APPROVED DEVELOPMENT PROJECT.

7. EXPOSED ROOTS: EXPOSED ROOTS SHALL BE COVERED AT THE END OF THE WORK DAY BY USING TECHNIQUES SUCH AS COVERING THE ROOTS WITH SOIL, MULCH, OR WET BURLAP.

TREE PROTECTION NOTES

8. HAND DIG AROUND EXISTING TREES.

T.R.

RIP RAP DRAINAGE AREA

POISON OAK REMOVAL, SEE
NOTE 3

TO BE REMOVED

TO REMAIN, PROTECT

IN PLACE

DEMOLITION NOTES
EXISTING CONCRETE CURB T.B.R. APPROX. 21 LF.

SAWCUT AT NEAREST JOINT. LIMITS OF REMOVAL PER

COORDINATES PROVIDED ON SITE CONSTRUCTION
PLAN.

EXISTING CONCRETE CURB T.R.

EXISTING STORM DRAIN INLET T.R.

EXISTING WATER METER AND BOX T.R.

EXISTING SWALE, REMOVE, STOCKPILE, AND
REMEDIATE RIP RAP.

REMOVAL AND REPLACE EXISTING RIP RAP

REMOVAL AND REPLACE EXISTING FENCE

REMOVE STOCKPILE AND RELOCATED RIP RAP
EXISTING SUBSURFACE DRAIN APPROX. LOCATION.

EXISTING 4" PERFORATED CORRUGATED DRAINAGE
PIPE.

EXISTING 4" SOLID CORRUGATED HDPE PIPE.

MONITORING WELL T.R.
1 2
3 4
5 6
7 8
9 10
11 12
NONE
3 NONE T:\Projects\2017 Projects\17058_HiddenGlenPark\3_ConstructionDocuments\A17058_DM.dwg NO.

REVISIONS
DESCRIPTION ELEV.

DESCRIPTION:

BENCH MARK

DATE BY
HORIZ.

SCALE
15 HIDDEN GLEN DUMP REMEDIATION
DRAWN BY:

DESIGNED BY:

CHECKED BY:

BS
MR
DATE
DATE
DATE
DATE:

CAD FILE:

DRAWING NO.

SHEET NO. OF
VERT.

RH/OP 10/14/24
5/22/24
5/22/24
OCTOBER 14, 2024

DEMOLITION PLAN

2.0 A17058_DM.dwg

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ATTACHMENT 6

EROSION CONTROL LEGEND

STABILIZED CONSTRUCTION ENTRANCE

CONSTRUCTION STAGING AND MATERIAL

STORAGE AREA

FIBER ROLL BARRIER

STORM DRAIN INLET PROTECTION

METAL FENCING PER SITE CONSTRUCTION PLANS

SILT FENCE
EROSION CONTROL BLANKET PER EC-7 OF

CASQA CONSTRUCTION BMP HANDBOOK
2 L3.2
1 L3.2
4 L3.2
3 L3.2

1. LANDFILL CAP PROTECTION: REFER TO SPECIAL PROVISIONS SECTION 00 72 00 GENERAL REQUIREMENTS, SECTION 1.3.C FOR LANDFILL CAP PROTECTION REQUIREMENTS.

PROJECT DESCRIPTION AND PURPOSE:

TOTAL DISTURBED AREA: 1.60 ACRES
TOTAL PROJECT SIZE: 1.66 ACRES
NEAREST RECEIVING WATER:

PLANNED PROJECT START DATE:

PLANNED GRADING COMPLETION DATE:

PLANNED PROJECT COMPLETION DATE:

I CERTIFY THAT THE INFORMATION PROVIDED IN THE EROSION AND SEDIMENT CONTROL PLAN IS, TO THE BEST OF MY KNOWLEDGE AND BELIEF, TRUE, ACCURATE, AND COMPLETE AND THAT IT WILL IMPLEMENT THROUGHOUT THE PROJECT. I

FURTHER CERTIFY THAT I WILL NOTIFY THE CITY OF NAPA CA AND SUBMIT REVISED INFORMATION IF ANY IF THE INFORMATION OR CONDITION DOCUMENTED IN THIS EROSION AND SEDIMENT CONTROL PLAN CHANGE. I UNDERSTAND THERE ARE

SIGNIFICANT PENALTIES FOR SUBMITTING FALSE INFORMATION OR FOR NOT IMPLEMENTING THE EROSION AND SEDIMENT CONTROL; PLAN PER NMC 8.36.00 STORMWATER RUNOFF POLLUTION CONTROL. I WILL RETAIN A COPY IF THE EROSION AND SEDIMENT CONTROL PLAN AT THE PROJECT SITE.

SIGNATURE:

PRINT/TYPE NAME:

TITLE:

DATE:

PROJECT INFORMATION

APPLICANT CERTIFICATION

EROSION AND SEDIMENT CONTROL NOTES WPB
SD

SD WPB SL SLPGE
W
W
PGE
PG&E
SL
3 L3.2

CONCRETE WASHOUT AREA SHALL
BE PER BMP MANUAL WM-8.

INSTALL FIBER ROLL

BARRIERS ON SLOPE PER

APPROXIMATE LIMIT
OF LANDFILL CAP.

APPROXIMATE LIMIT
OF LANDFILL CAP.

APPROXIMATE LIMIT
OF LANDFILL CAP.

LAYOUT APPROX. DISTANCES

BASED ON FIBER ROLE DETAIL

EXISTING FENCE

EXISTING FENCE

APPROXIMATE LIMIT
OF LANDFILL CAP.

NONE
4 NONE
FOR EROSION CONTROL DETAILS SEE SHEET 3.1 T:\Projects\2017 Projects\17058_HiddenGlenPark\3_ConstructionDocuments\A17058_EC.dwg NO.

REVISIONS

DESCRIPTION
DESCRIPTION:

ELEV.

BENCH MARK

DATE BY
HORIZ.

SCALE
15 HIDDEN GLEN DUMP REMEDIATION DRAWN BY:

DESIGNED BY:

CHECKED BY:

BS
MR
DATE
DATE
DATE
SHEET NO.

DRAWING NO.

CAD FILE:

DATE:

OF
VERT.

RH/OP
5/22/24
10/14/24
5/22/24
OCTOBER 14, 2024

EROSION CONTROL PLAN

3.0 A17058_EC.dwg
NORTH
0 20 feet
1" = 20'
40 ... , ... .. ... • .,. .. · .. . . .

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THE FOLLOWING NOTES REPRESENT MINIMUM ENFORCEMENT NOTES. THE CONTRACTOR IS RESPONSIBLE TO ENFORCE THE BEST MANAGEMENT PRACTICES AT THE SITE ALONG WITH OTHER SOURCES.

1. IN CASE OF EMERGENCY, CALL RESPONSIBLE PERSON AT (24 –HOUR TELEPHONE. PLEASE FILL IN NAME & NUMBER)

2. A STAND-BY CREW FOR EMERGENCY WORK SHALL BE AVAILABLE AT ALL TIMES. NECESSARY MATERIALS SHALL BE AVAILABLE

ON-SITE AND STOCKPILED AT CONVENIENT LOCATIONS TO FACILITATE RAPID CONSTRUCTION OF EMERGENCY DEVICES WHEN RAIN IS IMMINENT.

3. EROSION CONTROL DEVICES SHOWN ON THIS PLAN MAY BE REMOVED WHEN APPPROVED BY THE BUILDING OFFICIAL IF THE GRADING OPERATION HAS PROGRESSED TO THE POINT WHERE THEY ARE NO LONGER REQUIRED.

4. GRADED AREAS ADJACENT TO FILL SLOPES LOCATED AT THE SITE PERIMETER MUST DRAIN AWAY FROM THE TOP OF SLOPE AT THE CONCLUSION OF EACH WORKING DAY. ALL LOOSE SOILS AND DEBRIS THAT MAY CREATE A POTENTIAL HAZARD TO OFF-SITE PROPERTY SHALL BE STABILIZED OR REMOVED FROM THE SITE ON A DAILY BASIS.

5. ALL SILT AND DEBRIS SHALL BE REMOVED FROM ALL DEVICES WITHIN 24 HOURS AFTER EACH RAINSTORM AND BE DISPOSED OF PROPERLY.

6. A GUARD SHALL BE POSTED ON THE SITE WHENEVER THE DEPTH OF WATER IN ANY DEVICES EXCEEDS TWO FEET. THE DEVICE SHALL BE DRAINED OR PUMPED WITHIN 24 HOURS AFTER EACH RAINSTORM. PUMPING AND DRAINING OF ALL BASINS AND DRAINAGE DEVICES MUST COMPLY WITH THE APPROPRIATE BMP FOR DEWATERING OPERATIONS.

7. THE PLACEMENT OF ADDITIONAL DEVICES TO REDUCE EROSION DAMAGE AND CONTAIN POLLUTANTS WITHIN THE SITE IS LEFT TO THE DISCRETION OF THE FIELD ENGINEER. ADDITIONAL DEVICES AS NEEDED SHALL BE INSTALLED TO RETAIN SEDIMENTS AND OTHER POLLUTANTS ON SITE.

8. DESILTING BASINS MAY NOT BE REMOVED OR MADE INOPERABLE BETWEEN NOVEMBER 1 AND APRIL 15 OF THE FOLLOWING YEAR WITHOUT THE APPROVAL OF THE CITY.

9. STORMWATER POLLUTION AND EROSION CONTROL DEVICES ARE TO BE MODIFIED, AS NEEDED, AS THE PROJECT PROGRESSES, THE DESIGN AND PLACEMENT OF THESE DEVICES IS THE RESPONSIBILTY OF THE QUALIFIED SWPPP DEVELOPER/FIELD ENGINEER.

PLANS REPRESENTING CHANGES MUST BE SUBMITTED FOR APPROVAL.

10. EVERY EFFORT SHOULD BE MADE TO ELIMINATE THE DISCHARGE OF NONSTORMWATER FROM THE PROJECT SITE AT ALL TIMES.

11. ERODED SEDIMENTS AND OTHER POLLUTANTS MUST BE RETAINED ON SITE AND MAY NOT BE TRANSPORTED FROM THE SITE VIA SHEET-FLOW, SWALES, AREA DRAINS, NATURAL DRAINAGE COURSES, OR WIND.

12. STOCKPILES OF EARTH AND OTHER CONSTRUCTION-RELATED MATERIALS MUST BE PROTECTED FROM BEING TRANSPORTED FROM THE SITE BY THE FORCES OF WIND OR WATER.

13. CONTRACTOR TO FOLLOW CITY OF NAPA STANDARDS AND SPECIFICATIONS 1.10.02 WATER POLLUTION CONTROL.

14. FUELS, OILS, SOLVENTS, AND OTHER TOXIC MATERIALS MUST BE STORED IN ACCORDANCE WITH THEIR LISTING AND ARE NOT TO CONTAMINATE THE SOIL AND SURFACE WATERS. ALL APPROVED STORAGE CONTAINERS ARE TO BE PROTECTED FROM THE WEATHER. SPILLS MUST BE CLEANED UP IMMEDIATELY AND DISPOSED OF IN A PROPER MANNER. SPILLS MAY NOT BE WASHED INTO THE DRAINAGE SYSTEM.

15. EXCESS OR WASTE CONCRETE MAY NOT BE WASHED INTO THE PUBLIC RIGHT-OF- WAY OR ANY OTHER DRAINAGE SYSTEM.

PROVISIONS SHALL BE MADE TO RETAIN CONCRETE WASTES ON SITE UNTIL THEY CAN BE DISPOSED OF AS SOLID WASTE.

16. DEVELOPERS/CONTRACTORS/ QUALIFIED SWPPP DEVELOPERS (QSD)/ QUALIFIED SWPPP PRACTITIONER (QSP), ARE RESONSIBLE TO INSPECT ALL EROSION CONTROL DEVICES AND BMPS ARE INSTALLED AND FUNCTIONING PROPERLY, IF THERE IS A 50% CHANCE OF 0.25 INCHES OR GREATER OF PREDICTED PRECIPITATION, AND AFTER ACTUAL PRECIPITATION. A CONSTRUCTION

SITE INSPECTION CHECKLIST AND INSPECTION LOG SHALL BE MAINTAINED AT THE PROJECT SITE AT ALL TIMES AND AVAILABLE FOR REVIEW BY THE BUILDING OFFICIAL (SELF-INSPECTION CHECK LIST AND INSPECTION LOGS PER STATE SWPPP REQUIREMENTS).

INCIDENTS OF NON- COMPLIANCE MUST BE REPORTED TO THE FIELD ENGINEER.

17. TRASH AND CONSTRUCTION-RELATED SOLID WASTES MUST BE DEPOSITED INTO A COVERED RECEPTACLE TO PREVENT CONTAMINATION OF RAINWATER AND DISPERSAL BY WIND.

18. SEDIMENTS AND OTHER MATERIALS MAY NOT BE TRACKED FROM THE SITE BY VEHICLE TRAFFIC. THE CONSTRUCTION ENTRANCE ROADWAYS MUST BE STABILIZED SO AS TO INHIBIT SEDIMENTS FROM BEING DEPOSITED INTO THE PUBLIC RIGHT-OF- WAY.

ACCIDENTAL DEPOSITIONS MUST BE SWEPT UP IMMEDIATELY AND MAY NOT BE WASHED DOWN BY RAIN OR OTHER MEANS.

19. ANY SLOPES WITH DISTURBED SOILS OR DENUDED OF VEGETATION MUST BE STABILIZED SO AS TO INHIBIT EROSION BY WIND AND WATER.

20. PROVIDE STORMWATER CONVEYANCE SYSTEM STENCILING AND SIGNAGE FOR BOTH PRIVATE DEVELOPMENT AND PUBLIC RIGHT OR WAY.

20.1. PROVIDE CONCRETE STAMPING, OR EQUIVALENT, OF ALL STORMWATER CONVEYANCE SYSTEM INLETS AND CATCH BASINS WITHIN THE PROJECT AREA WITH PROHIBITIVE LANGAUAGE (E.G., “NO DUMPING DRAINS TO NAPA RIVER”).

20.2. POST SIGNS AND PROHIBITIVE LANGUAGE AND/OR GRAPHICAL ICONS, WHICH PROHIBIT ILLEGAL DUMPING AT PUBLIC

ACCESS POINTS ALONG CHANNELS AND CREEKS WITHIN THE PROJECT AREA, TRAILHEADS, PARKS, BUILDING ENTRANCES AND BIORTENTION FACILITIES. THE FOLLOWING BMPS FROM THE “CALIFORNIA STORM WATER BMP CONSTRUCTION HANDBOOK” – NOVEMBER 2009, OR LATEST EDITION, OR EQUAL, MUST BE IMPLEMENTED FOR ALL CONSTRUCTION ACTIVITIES AS APPLICABLE. ADDITIONAL MEASURES MAY BE REQUIRED IF DEEMED APPROPRIATE BY CITY INSPECTORS. ONLY INCLUDE BMP’S REFERENCED PROJECT ON THE SITE MAP.

EROSION AND SEDIMENT CONTROL/SWPPP PLAN NOTES
NONE
5 NONE
FOR EROSION CONTROL DETAILS SEE SHEET 3.2 T:\Projects\2017 Projects\17058_HiddenGlenPark\3_ConstructionDocuments\A17058_EC.dwg NO.

REVISIONS

DESCRIPTION
DESCRIPTION:

ELEV.

BENCH MARK

DATE BY
HORIZ.

SCALE
15 HIDDEN GLEN DUMP REMEDIATION DRAWN BY:

DESIGNED BY:

CHECKED BY:

BS
MR
DATE
DATE
DATE
SHEET NO.

DRAWING NO.

CAD FILE:

DATE:

OF
VERT.

RH/OP
5/22/24
10/14/24
5/22/24
OCTOBER 14, 2024

EROSION CONTROL PLAN

3.1 A17058_EC.dwg

PROJECT BEST

MANAGEMENT PRACTICES
(BMP)

BMP MAINTENANCE SCHEDULE BMP INSTALLATION SCHEDULE

WET/DRY

SEASONS BMP INSPECTION FREQUENCY MAINTENANCE CLEARING GRADING UTILITIES PAVING POSTCONSTRUCTION
BOTH

STABILIZED

CONSTRUCTION

ENTRNACE

DAILY REPLACE GRAVEL AS NECESSARY, REMOVE EXCESSIVE SOIL ACCUMULATION, SWEEP ADJACENT STREETS DAILY. X X X X

BOTH FIBER ROLL PRIOR TO AND AFTER RAIN EVENT, AND

DURING EXTENDED RAIN EVENTS
REPAIR OR REPLACE SPLIT, TORN, UNRAVELING OR SLUMPING ROLLS. IN ACTIVE CONSTRUCTION,

RETURN ROLLS THAT HAVE BEEN MOVED TO PROPER PLACES AT THE END OF EACH WORKDAY DURING THE WET SEASON.

X X X

BOTH STRAW MULCH AFTER EACH RAIN EVENT REAPPLY MULCH AND TACKIFIER AS NECESSARY, SLOPES MAINTAINED AND REPAIRED IMMEDIATELY AFTER RAIN EVENT. X X X X X
BOTH

INLET SEDIMENT

CONTROL

WEEKLY, AND PRIOR TO AND AFTER RAIN
EVENTS

MATERIAL SPILLING FROM SEDIMENT CONTROL DEVICES SHALL BE CLEANED UP AND REPAIRED OR REPLACE IMMEDIATELY. DISPOSE OF SEDIMENT PROPERLY. X X X X

BOTH CONCRETE
WASHOUTS DAILY MINIMUM OF 4' OF FREEBOARD, HARDENED CONCRTE SHALL BE REMOVED AND DISPOSED OF PROPERLY. WASHOUT SHALL BE CLEANED WHEN THE WASTE VOLUME REACHES 75% CAPACTY. X BOTH

STREET SWEEPING
AND

VACCUMING

WEEKLY AND PRIOR TO AND AFTER RAIN
EVENTS. WHEN IN USE DAILY
REMOVE SEDIMENT AT LEAST DAILY. ADJUST BROOMS FREQUENTLY. DISPOSE OF SWEEPER WASTES AT APPROVED DUMP SITES. X X X X

WET SEDIMENT TRAP WEEKLY AND PRIOR TO AND AFTER RAIN
EVENTS
SEDIMENT SHALL BE REMOVED FROM THE BOTTOM OF THE TRAP WHEN 300MM (1 FOOT) DEEP OR LESS. X X X
11:; 11 ~,O T1ibui.,111y Pn'nil D11iv,1e
Gold Rlve" 9'5570

UTILITIES DEPARTMENT

NONE
6 NONE
1 3.2

STABILIZED CONSTRUCTION ENTRANCE

PLAN/SECTION
NOTE:

1. STABILIZED CONSTRUCTION SITE

ACCESS SHALL BE CONSTRUCTED
OF 3" TO 6" WASHED,

WELL-GRADED GRAVEL OR
CRUSHED ROCK. MATERIAL SHALL

BE PLACED TO A MINIMUM
THICKNESS OF 6 INCHES.

2. LENGTH OF ENTRANCE SHALL BE A
MINIMUM OF 50 FT. WIDTH SHALL BE
A MIN. OF 15 FT OR GREATER IF

NECESSARY TO COVER ALL
VEHICULAR INGRESS AND EGRESS.

PROVIDE AMPLE TURNING RADII.

3. THE ENTRANCE SHALL BE KEPT IN

GOOD CONDITION BY

OCCASIONAL TOP DRESSING WITH
MATERIAL AS SPECIFIED IN NOTE 1.

4. ACCESS SHALL BE INSPECTED

WEEKLY DURING PERIODS OF

HEAVY USAGE, MONTHLY DURING

NORMAL USAGE, AND AFTER EACH

RAINFALL, WITH MAINTENANCE
PROVIDED AS NECESSARY.

PERIODIC TOP DRESSING SHALL BE
DONE AS NEEDED.

CONSTRUCTION SITE RIGHT OF WAY

EXISTING
GROUND
50 FT MINIMUM

SECTION A-A
A A

DIRECTION
OF TRAVEL 15'-0" MIN.

PLAN VIEW

GEOTEXTILE

MATERIAL

STABILIZED CONSTRUCTION

SITE ACCESS
2 3.2

FIBER ROLL BARRIER

SECTION
4 3.2

STORM DRAIN INLET PROTECTION

PLAN/SECTION

FIBER ROLL
3 4
" X 3
4 " X 24" STAKES

SIDEWALK OR OTHER

IMPROVEMENT WHERE
IT OCCURS.

NOTES:

1. FIBER ROLL BARRIER SHALL BE CONSTRUCTED

LONG ENOUGH TO EXTEND ACROSS THE

EXPECTED FLOW PATH AND AS APPROVED
BY THE CITY REPRESENTATIVE.

2. FIBER ROLL (8" TO 12" DIAMETER) SHALL BE

PLACED INTO THE KEY TRENCH AND STAKES
ON BOTH SIDES OF THE ROLL WITHIN 5 FEET
OF EACH END AND THEN EVERY 3' TO 4'.

STAKES OF SHALL BE DRIVEN IN ON
ALTERNATING SIDES OF THE ROLL. ADJACENT
ROLLS SHALL TIGHTLY ABUT.

3. CLEAR SUBGRADE TO REMOVE ALL LOCAL

DEVIATIONS AND LARGE STONES OR DEBRIS

THAT WILL INHIBIT CONTACT OF THE FIBER
ROLL WITH THE SUBGRADE.

4. PRIOR TO ROLL INSTALLATION, CONSTRUCT A
CONCAVE TRENCH 2 INCHES DEEP ALONG
THE PROPOSED INSTALLATION ROUTE. FIBER

ROLL SHALL BE INSTALLED WHERE INDICATED
ON PLANS. THE BOTTOM EDGE OF THE FIBER

ROLL SHALL EXTEND TO AND ACROSS THE
BOTTOM OF THE TRENCH. THE TRENCH SHALL
BE BACKFILLED TO 4 INCHES ABOVE

GROUND AND COMPACTED TO BURY AND
SECURE THE BOTTOM OF THE FIBER ROLL.

FLOW
2" MIN.
4" MAX.
6" MIN. TYP. 12" MIN.
17058_FilterRollBarrier.dwg T:\Projects\2017 Projects\17058_HiddenGlenPark\3_ConstructionDocuments\A17058_EC.dwg NO.

REVISIONS

DESCRIPTION
DESCRIPTION:

ELEV.

BENCH MARK

DATE BY
HORIZ.

SCALE
15 HIDDEN GLEN DUMP REMEDIATION DRAWN BY:

DESIGNED BY:

CHECKED BY:

BS
MR
DATE
DATE
DATE
SHEET NO.

DRAWING NO.

CAD FILE:

DATE:

OF
VERT.

RH/OP
5/22/24
10/14/24
5/22/24
OCTOBER 14, 2024

EROSION CONTROL DETAILS
3 3.2

FIBER ROLL BARRIER
SECTION 12" MIN.

INSTALL A FIBER

ROLL NEAR

TRANSITION TO

STEEPER SLOPE
SLOPE 4:1 OR FLATTER, SPACE
AT 20'-0" MAX SLOPE BETWEEN
4:1 AND 2:1, SPACE AT 15'
MAX SLOPE 2:1 OR STEEPER,
SPACE AT 10' MAX.
3/4" X 3/4" X 24"
STAKES

FIBER ROLL
FLOW
6" MIN.

TYP.
2" MIN.
4" MAX.

ON SLOPES 3:1 OR

STEEPER, INSTALL

JUTE NETTING PER
BMP MANUAL EC-7
NOTES:

1. REFER TO NOTES ON DETAIL 2 OF THIS SHEET FOR ADDITIONAL REQUIREMENTS.

2. INSTALL FIBER ROLL ALONG LEVEL CONTOUR.

3. TURN ENDS OF FIBER ROLL UP SLOPE 4'-0" MIN. TO PREVENT RUNOFF FROM GOING AROUND ROLL.

FOR EROSION CONTROL PLAN SEE SHEET 3.0

3.2 A17058_EC.dwg
N.T.S. N.T.S. N.T.S.

ROCK FILTER (USE IF FLOW

IS CONCENTRATED)

CONCENTRATED
FLOW

SHEET FLOW

SHEET FLOW
XX
00 SILT FENCE PER

GEOTEXTILE

BLANKET

DRAIN INLET

EDGE OF

SEDIMENT TRAP

SHEET FLOW PLAN
A

STABILIZE AREA AND

GRADE UNIFORMLY

AROUND PERIMETER
1:1 SLOPE
NOTE:

REMOVE SEDIMENT

BEFORE REACHING
ONE-THIRD FULL.

DRAIN INLET

SILT FENCE

SECTION A-A

GEOTEXTILE

BLANKET
-j
,--._ '('-'-'_:_ ... _;\ ''-=-)( __ / ~-.()/ ·,.,;~ J.-'._ 1/,(- "•\,:(f \ _ _,'(\ /, _;I~ 1 , __ ,, --,J, ,, -·,xc .... ,•,-.)..___, \..,, /=-<'-. . /\l \_A. __ J1_:: _)--'!.¢ C) r L
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UTILITIES DEPARTMENT
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Gold Rlve" 9'5570
Ctl,IJl, ?rcie::lt N,r1 17G58A

WPB
SD

SD WPB SL SLPGE
W
W
PGE
PG&E
SL

APPROXIMATE LIMIT OF

LANDFILL CAP

PROTECT IN PLACE

PROTECT IN PLACE

PROTECT IN PLACE,

ENCASE MONITOR
WELL PER DETAIL 8/6.0

REMOVE EXISTING RIP RAP AND STOCKPILE

ONSITE FOR REUSE
2 4.1
4 4.1
5 4.1
6 4.1
8 4.1
3 4.1
1 4.2
4 4.2
3 4.2
7 4.1
1 4.1
2 4.2
5 4.2
6 4.2
REMOVAL 4122 SF,
153 CY
REMOVAL 213 SF

2.8 CY
REMOVAL 1,527 SF, 20 CY

DEBRIS AREA
6,895 SF
REMOVAL 2,923 SF
108 CY
REMOVAL 137 SF

1.7 CY
REMOVAL 2316 SF,
57 CY
REMOVAL 101 SF, 1.25 CY
REMOVAL 253 SF, 8.6 CY
REMOVAL 87 SF,

1.1 CY
REMOVAL 982 SF, 37 CY
REMOVAL 1,090 SF, 33.7 CY
REMOVAL 154 SF
2 CY
REMOVAL 563 SF

17.4 CY
REMOVAL 746 SF
26 CY
REMOVAL 549 SF

20.3 CY
REMOVAL 2,236 SF
14 CY
REMOVAL 1,360 SF
42 CY
REMOVAL 327 SF

11.2 CY
HORIZONTAL AND VERTICAL CONTROL: MAG

NAIL SET IN CURB ON PASCALE PLACE AT
NORTHING 1870374.71 AND EASTING 6484988.00
AT ELEVATION 104.76

HORIZONTAL AND VERTICAL
CONTROL: MAG NAIL SET IN
ROCK AT NORTHING 1870304.73
AND EASTING 6485232.28 AT
ELEVATION 138.89
CONTROL POINT #2

HORIZONTAL AND VERTICAL
CONTROL: 3/4" IRON PIPE

WITH RED CONTROL CAP AT
NORTHING 1870491.19 AND
EASTING 6485175.66 AT
ELEVATION 136.65
EXISTING 4" PVC DRAIN LINE ENCASED
IN CONCRETE, PROTECT IN PLACE.

EXISTING 4" PVC PERFORATED DRAIN LINE IN POLYETHYLENE LINED

GRAVEL TRENCH AT EDGE OF LANDFILL CAP, PROTECT IN PLACE

FL MATCH (E)
105.25
TC 105.70
BVC 105.65 TC MATCH (E)
107.98
131
132
133
134
135
136
137
REMOVAL 79 SF,
1 CY
REMOVAL 1126 SF,
13 CY
REMOVAL 458 SF,
32 CY
REMOVAL 1190 SF

7.3 CY
7 T:\Projects\2017 Projects\17058_HiddenGlenPark\3_ConstructionDocuments\A17058_WE.dwg NO.

REVISIONS

DESCRIPTION
DESCRIPTION:

ELEV.

BENCH MARK

DATE BY
HORIZ.

SCALE
15 HIDDEN GLEN DUMP REMEDIATION DRAWN BY:

DESIGNED BY:

CHECKED BY:

BS
MR
DATE
DATE
DATE
SHEET NO.

DRAWING NO.

CAD FILE:

DATE:

OF
VERT.

RH/OP
5/22/24
10/14/24
5/22/24
OCTOBER 14, 2024

WASTE EXCAVATION PLAN

4.0 A17058_WE.dwg
0 20 feet
1" = 20'
40 NORTH
SOIL WITH WASTE REMOVAL (<10")
SOIL WITH WASTE REMOVAL (10"-20")
SOIL WITH WASTE REMOVAL (21"-30")
RELOCATED SOIL WITH WASTE (TOTAL STOCKPILE DEBRIS = 495 CY)

SECTION CUT
EXISTING CONTOUR: 1'-0" INTERVAL TYP.

PROPOSED CONTOUR FOR SOIL WITH WASTE MOUND: 1'-0" INTERVAL TYP.

PROPOSED SPOT ELEVATION (EXISTING SPOT ELEVATIONS ARE SCREENED ON PLAN)

DIRECTION AND PERCENT SLOPE OF SHEET DRAINAGE

GRADE BREAK

FLUSH CONDITION

CONTROL POINT

HIGH POINT

TOP OF CURB

BOTTOM OF CURB

TOP OF WALL

BOTTOM OF WALL

TOP OF RAMP

BOTTOM OF RAMP

RIM ELEVATION OF DRAIN INLET, SEE WALL AND DRAINAGE PLAN VERTICAL CURVE PER CHP HIGHWAY DESIGN MANUAL SECTION 200-24

BEGINNING OF VERTICAL CURVE

END OF VERTICAL CURVE

GRADE BREAK
X%
GB

1. GRADING: CONTRACTOR SHALL PERFORM ALL EARTHWORK AND GRADING PER GEOTECHNICAL ENGINEER'S RECOMMENDATIONS.

2. LANDFILL CAP PROTECTION: REFER TO SPECIAL PROVISIONS SECTION 00 72 00 GENERAL REQUIREMENTS, SECTION 1.3.C FOR LANDFILL CAP PROTECTION REQUIREMENTS.

3. MAXIMUM EXCAVATION REQUIRED. AMOUNT OF EXCAVATION MAY BE REDUCED IF BEDROCK IS ENCOUNTERED AT SHALLOW DEPTHS.

HP
TC
BC
TW
BW
TR
BR
RIM
VC
BVC
EVC
GB

WASTE EXCAVATION NOTES

21.25 22
X
XX
22 CONTROL POINT #1 PA

LIMIT OF
C)
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0' 5' 10' 15' 20' 25' 30' 35' 40' 45' 50' 55' 60' 65' 70' 75' 80' 85' 90' 95' 100' 105'
110'
115'
120'
125'
130'
135'
0' 5' 10' 15' 20' 25' 30' 35' 40' 45' 50' 55' 60' 65' 70' 75' 80' 85' 90' 95' 100' 105'
110'
115'
120'
125'
130'
135'
0' 5' 10' 15' 20' 25' 30'
120'
130'
140'
125'
135'
0' 5' 10' 15' 20'
120'
130'
140'
125'
135'
130'
140'
125'
135'
0' 5' 10' 15' 20' 25' 30'
115'
125'
135'
120'
130'
0' 5' 10' 15'
110'
120'
130'
115'
125'
EX. CURB
EX. ROAD
(PASCALE PLACE)
EX. CURB
EX. ROAD
(PASCALE PLACE)
LOT 7
LOT 12
35' 40'
25' 30'
LOT 9
LOT 9
LOT 9
LOT 10
0' 5' 10' 15' 20' 25' 30'
145'
150'
105'
45'
4'-0"
130'
140'
135'
145'
125'
150'
155'
120'
115'
-5'
-5'
-5' -20' -15' -10' -5' 20'
-10' -5'
-5'
-10' -5'
-230' -225' -220' -215' -210' -205' -200' -195' -190' -185' -180' -175' -170' -165' -160' -155' -150' -145' -140' -135' -130' -125' -120' -115' -110' -105' -100' -95' -85'-90' -80' -75' -65'-70' -60' -55' -45'-50' -40' -35' -25'-30' -20' -15' -10' -5' 0' 5' -10'

PROPERTY LINE
EX. GRADE
EX. BEDROCK

PROPERTY LINE
EX. GRADE
EX. BEDROCK

PROPERTY LINE
EX. GRADE

APPROXIMATE LIMIT

OF LANDFILL CAP
EX. TOP SOIL
EX. WASTE
EX. GEOCOMPOSITE

DRAINAGE NET &

POLYETHYLENE

MEMBRANE
EX. FOUNDATION
FILL (24")
EX. GRADE

REMOVE EXISTING SOIL

WITH WASTE
EX. GALVANIZED STEEL FENCE,
TEMPORARILY REMOVE.

EX. GALVANIZED STEEL FENCE

PROPERTY LINE
EX. FENCE
EX. GRADE

APPROXIMATE LIMIT OF

LANDFILL CAP
EX. TOP SOIL
EX. GEOCOMPOSITE

DRAINAGE NET &

POLYETHYLENE MEMBRANE
EX. WASTE
EX. FOUNDATION
FILL (18" MIN.)

PROPERTY LINE
EX. GRADE
EX. TOP SOIL
EX. GEOCOMPOSITE

DRAINAGE NET &

POLYETHYLENE MEMBRANE
EX. WASTE
EX. FOUNDATION
FILL (18" MIN.)

PROPERTY LINE

APPROXIMATE LIMIT

OF LANDFILL CAP

FINISHED GRADE

APPROXIMATE LIMIT OF LANDFILL CAP

PROPERTY LINE
EX. BEDROCK

EXISTING TREE, HAND DIG

FOR MAINTENANCE

VEHICLE ACCESS
EX. BEDROCK

SOIL WITH WASTE

SOIL WITH WASTE

SOIL WITH
WASTE

SOIL WITH WASTE

SOIL WITH WASTE

PROPERTY LINE

REMOVE EXISTING SOIL WITH
WASTE

APPROXIMATE LIMIT OF

LANDFILL CAP
EX. PROPERTY LINE
EX. BED ROCK
EX. BED ROCK
EX. BED ROCK
EX. BOULDER
EX. BED ROCK
EX. BED ROCK
EX. GEOCOMPOSITE

DRAINAGE NET &

POLYETHYLENE MEMBRANE
EX. FOUNDATION FILL
(18" MIN.)

REMOVE EXISTING SOIL WITH
WASTE

REMOVE EXISTING SOIL

WITH WASTE

REMOVE EXISTING SOIL

WITH WASTE

REMOVE EXISTING SOIL WITH

REMOVE EXISTING SOIL WITH WASTE
WASTE
EX. GEOCOMPOSITE DRAINAGE NET &

POLYETHYLENE MEMBRANE
EX. GRADE
EX. TOP SOIL
EX. WASTE
EX. FOUNDATION FILL (18" MIN.)

SOIL WITH WASTE FILL,

SEE PLAN FOR DEPTH
EX. TOP SOIL
EX. WASTE
EX. GEOCOMPOSITE

DRAINAGE NET &

POLYETHYLENE

MEMBRANE
EX. FOUNDATION
FILL (24")
EX. TOP SOIL
EX. WASTE
EX. GEOCOMPOSITE

DRAINAGE NET &

POLYETHYLENE

MEMBRANE
EX. FOUNDATION
FILL (24")

APPROXIMATE LIMIT

OF LANDFILL CAP

APPROXIMATE LIMIT

OF LANDFILL CAP
EX. TOP SOIL

UPDATED
EX. GRADE
8 T:\Projects\2017 Projects\17058_HiddenGlenPark\3_ConstructionDocuments\A17058_WE.dwg NO.

REVISIONS

DESCRIPTION
DESCRIPTION:

ELEV.

BENCH MARK

DATE BY
HORIZ.

SCALE
15 HIDDEN GLEN DUMP REMEDIATION DRAWN BY:

DESIGNED BY:

CHECKED BY:

BS
MR
DATE
DATE
DATE
SHEET NO.

DRAWING NO.

CAD FILE:

DATE:

OF
VERT.

RH/OP
5/22/24
10/14/24
5/22/24
OCTOBER 14, 2024

WASTE EXCAVATION SECTIONS

4.1 A17058_WE.dwg
r
I ~
I //
:4 ..,.7 \I , _: 0,. If
\ . -·--
. . . . hr"::' .. -11"(.:-
~ \ .
,, - ' --• = • > . . " ' / -::_::~;>-- ... ,..., _,//
l l . A II
" I
@SECTION1 4.1 SECTiall VERTICAL SCALE: 1"-10' HORIZONTAL SCALE: 1"-10' r
r ~
I ... - . . . . --. . / ' ----. -,,,,,, ____ ., -
_) --- - --
./ ----- 11··· I I l ,I ...
' .• . \l
~ ··)[ Ja-11 .
------::::;,- J_ }k-., ~ \\ 71 ::/ , I ..
@SECTION4 4.1 SECTION VERTICAL SCALE: 1"-10' HORIZONTAL SCALE: 1"-10' SECTION 7
SECTION VERTICAL SCALE: 1"-10' HORIZONTAL SCALE: 1"-10' -
\ . - -· . .. . I .. . ?"1' Ii . ----, _,_ . - --- ___ .,.,- " -- - \ \\ . - . --. --'I-. II -~~::___,\C A •. - l
' " A ,_ /1. " "-- - "-,-
\
. - - .--L I - -
- ..
. -. .. ,,-·' --- tr J: . . ,/'
. . . - - -- - - /
. -------- --1r· - 1"( \ A l 'N
- " . . --,.,:- ----c
- - (( \ II N
~
'
\__
- ___ .:-'Su -c_iu.
ll re, "
" • \\
I
-. . - - -- .. T
(
- " ('( \~
I
I
I
I
I
:n;.i:;:::1 , -= V
tp, V
"
" ~
-~
--+---1--
@SECTION2 4.1 SECTlON vEHhCAL SCALE: f'-5' HORIZONTAL SCALE: f'-5' ~
11; Jf
((
~
·-.J'~;
LU SECTION 5 ~ SECTlON vEHhCAL SCALE: f'-5' HORIZONTAL SCALE: f'-5'

UTILITIES DEPARTMENT
'!:> \.. ' i,
._ .....:....\. L.

SECTION 3
!
SECTION VERTICAL SCALE: f'-5'
___ 0-
HORIZONTAL SCALE: f'-S'
@SECTIONS
[C SECTION VERTICAL SCALE: f'-5' HORIZONTAL SCALE: f'-S' @ SECTIONS
1 SECTION VERTICAL SCALE: 1'-10' HORIZONTAL SCALE: 1"-10' 11711 ~,O T1ibui.my Po'nil D11iv,e
Gold Rlve" 9'5570
Ctl,IJl, ?rcje::lt No. 17G58A

120'
130'
140'
125'
135'
0' 5' 10' 15' 20' 25' 30'
120'
130'
140'
125'
135'
35' 40' 45'
0' 5' 10' 15' 20' 25' 30'
110'
120'
130'
115'
125'
35' 40' 45'
LOT 5
LOT 6 LOT 6
0' 5' 10' 15' 20' 25' 30'
120'
130'
125'
135'
35' 40' 45' 50'
115'
55'
LOT 5
0' 5' 10' 15' 20' 25' 30' 35' 40' 45' 50'
130'
125'
135'
LOT 6 145'
140'
-15' -10' -5' -5'
-10' -5' -10' -5'
-10' -5' 0' 5' 10' 15' 20' 25' 30' 35' 40' 45' 50'
120'
130'
140'
125'
135'
LOT 9
-20' -15' -10' -5' 0' 5' 10' 15' 20'
EX. TOP SOIL
EX. WASTE
EX. GEOCOMPOSITE DRAINAGE

NET & POLYETHYLENE

MEMBRANE
EX. FOUNDATION FILL (18" MIN.)
EX. FENCE

PROPERTY LINE
EX. GRADE

APPROXIMATE LIMIT OF LANDFILL CAP

PROPERTY LINE
EX. GRADE
EX. TOP SOIL
EX. WASTE
EX. GEOCOMPOSITE DRAINAGE NET
& POLYETHYLENE MEMBRANE
EX. FOUNDATION
FILL (18" MIN.)
EX. GRADE

APPROXIMATE LIMIT OF LANDFILL CAP
EX. TOP SOIL
EX. WASTE
EX. GEOCOMPOSITE

DRAINAGE NET &

POLYETHYLENE

MEMBRANE
EX. FOUNDATION
FILL (18" MIN.)
EX. FENCE

PROPERTY LINE
EX. TOP SOIL
EX. WASTE
EX. GEOCOMPOSITE

DRAINAGE NET &

POLYETHYLENE MEMBRANE
EX. FOUNDATION FILL (18" MIN.)
EX. FENCE

PROPERTY LINE
EX. GRADE

APPROXIMATE LIMIT OF

LANDFILL CAP

EXISTING TREE,

HAND DIG
APPROXIMATE LOCATION OF EX. DECK
EX.

WALL

SOIL WITH WASTE

SOIL WITH WASTE

SOIL WITH WASTE
EX. FENCE
EX. GRADE
EX. DECK IN APPROXIMATE LOCATION

PROPERTY LINE

SOIL WITH WASTE
EX. BED ROCK

REMOVE AND REPLACE EXISTING RIP RAP
EX. TREE
EX. BED ROCK
EX. SHRUB
EX. FENCE
EX. BED ROCK

REMOVE EXISTING

SOIL WASTE

REMOVE EXISTING SOIL
WITH WASTE EX. BED ROCK

REMOVE EXISTING SOIL

WITH WASTE

REMOVE EXISTING SOIL

WITH WASTE
EX. BED ROCK

REMOVE EXISTING SOIL WITH WASTE

PROPERTY LINE

SOIL WITH WASTE
EX. BED ROCK
EX. FENCE
EX. GRADE NEW LAYER OF

SOIL WITH WASTE

REMOVE EXISTING SOIL

WITH WASTE
EX. TOP SOIL
EX. WASTE
EX. GEOCOMPOSITE DRAINAGE NET
& POLYETHYLENE MEMBRANE
EX. FOUNDATION
FILL (18" MIN.)
EX. NEW LAYER OF SOIL WITH WASTE

APPROXIMATE LIMIT OF

LANDFILL CAP
9 T:\Projects\2017 Projects\17058_HiddenGlenPark\3_ConstructionDocuments\A17058_WE.dwg NO.

REVISIONS

DESCRIPTION
DESCRIPTION:

ELEV.

BENCH MARK

DATE BY
HORIZ.

SCALE
15 HIDDEN GLEN DUMP REMEDIATION DRAWN BY:

DESIGNED BY:

CHECKED BY:

BS
MR
DATE
DATE
DATE
SHEET NO.

DRAWING NO.

CAD FILE:

DATE:

OF
VERT.

RH/OP
5/22/24
10/14/24
5/22/24
OCTOBER 14, 2024

WASTE EXCAVATION SECTIONS

4.2 A17058_WE.dwg
SECTION 1 SECTION 2
SECT10N ve«ICAL SCALE: f'-5' HOFIZONTAL SCALE: 1"-5' SECTION VERTICAL SCALE: 1"-5' HORIZONTAL SCALE: f'-5' I '
SECTION 3 SECTION 4
SECT10N vamcAL SCALE: f'-5' HOFIZONTAL SCALE: 1"-5' SECTION VERTICAL SCALE: 1"-5' HORIZONTAL SCALE: f'-5' ~,_lj,___________,_
SECTION 5 11711 ~,O T1ibui.my Po'nil D11iv,e
SECTION v&H'ICAL SCALE: f'-5' HORIZONTAL SCALE: 1"-5' Gold Rlve" 9'5570 Ctl,IJl, ?rcje::lt N,r1 17G58A

UTILITIES DEPARTMENT

SOIL COVER MATERIAL

SECTION CUT

SOIL REMEDIATION PILE CONTOUR
EXISTING CONTOUR: 1'-0" INTERVAL TYP.

PROPOSED CONTOUR: 1'-0" INTERVAL TYP.

PROPOSED SPOT ELEVATION (EXISTING SPOT ELEVATIONS ARE SCREENED ON PLAN)

DIRECTION AND PERCENT SLOPE OF SHEET DRAINAGE
SWALE WITH MIN. 2% SLOPE

GRADE BREAK

FLUSH CONDITION

CONTROL POINT

HIGH POINT

TOP OF CURB

BOTTOM OF CURB

TOP OF WALL

BOTTOM OF WALL

TOP OF RAMP

BOTTOM OF RAMP

RIM ELEVATION OF DRAIN INLET, SEE WALL AND DRAINAGE PLAN VERTICAL CURVE PER CHP HIGHWAY DESIGN MANUAL SECTION 200-24

BEGINNING OF VERTICAL CURVE

END OF VERTICAL CURVE

GRADE BREAK
X%
GB

GRADING AND DRAINAGE NOTES

1. GRADING AND DRAINAGE: ALL PROPOSED PAVING, CURBS, WALLS, AND PLANTING AREAS SHALL SMOOTHLY CONFORM TO EXISTING ADJACENT FEATURES TO REMAIN. PROVIDE POSITIVE DRAINAGE ON ALL PAVING AND THROUGHOUT ALL PLANTING AREAS.

2. SOIL STOCKPILE: STRIP AND STOCKPILE EXISTING 6" LAYER OF SOIL FROM AREAS DISTURBED DURING GRADING OR EXCAVATION.

3. GRADING: CONTRACTOR SHALL PERFORM ALL EARTHWORK AND GRADING PER GEOTECHNICAL ENGINEER'S RECOMMENDATIONS.

4. LANDFILL CAP PROTECTION: REFER TO SPECIAL PROVISIONS SECTION 00 72 00 GENERAL REQUIREMENTS, SECTION 1.3.C FOR LANDFILL CAP PROTECTION REQUIREMENTS.

HP
TC
BC
TW
BW
TR
BR
RIM
VC
BVC
EVC
GB
X
XX
XXX
XX
XX.XX WPB
SD

SD WPB SL PGE
W
W
PGE
PG&E
SL
L=128.47 , R=225.00 Δ=32° 42' 5 4" N46° 47' 37"E 106.48' N46° 47' 37"E 106.48'
N50° 43' 20"W

79.84'
L=18.12, R=32.00 Δ=32°26'37" N83° 10' 01"W

16.20'
N83° 10' 01"W
132.99' N73° 05' 03"W 67.99'
N16° 55' 11"E 58.30'
N16° 55' 11"E 327.88'
N68° 18' 22"W

24.07'
N70° 12' 09"W

18.42'
N65° 49' 13"W

54.38'
N36° 31' 56"W

25.19'
N12° 57' 00"W

29.06'
N41° 22' 49"W

25.60'
N62° 33' 25"W

22.11'
N73° 13' 30"E 20.26'
N67° 08' 28"W

71.16'
N22° 05' 10"W

59.78' N75° 55' 17"W 64.57'
N14° 04' 43"E

49.82'
N14° 04' 43"E
115.50'
N14° 04' 43"E
141.38'
N14° 04' 43"E
128.14' N75° 55' 17"W 16.01'
N14° 04' 43"E

80.00'
N14° 04' 43"E

29.69' N75° 55' 17"W 61.80'
N11° 23' 13"E 2.48'
N41° 16' 44"E 31.83' N74° 27' 57"W 42.29'
N37° 05' 54"E 42.14'
N11° 52' 43"E

35.16'
N48° 46' 49"E 77.69'
N66° 25' 41"W
120.04'
131
132
133
134
135
136
137
HP 131.80
2 5.1
5 5.1
6 5.1
8 5.1
3 5.1
1 5.2
4 5.2
3 5.2
2 5.2
5 5.2
7 5.1
4 5.1
1 5.1
HP 131.65
6 5.2
130
131
132
134
136
137
138
139
141
142
140
129
128
128
128
128
127
126
125
128
129
130
131
131
130
129
128
127
126
125
124
123
122
121
120
118
119
116
117
113
114
115
111
112
109
110
107
108
129
129
129
131
132
133
134
135
136
137
138
HP 138.25
HP 129.25
HP 127.8
135
133
10 5.0
A17058_GD.dwg T:\Projects\2017 Projects\17058_HiddenGlenPark\3_ConstructionDocuments\A17058_GD.dwg NO.

REVISIONS
DESCRIPTION ELEV.

DESCRIPTION:

BENCH MARK

DATE BY
HORIZ.

SCALE
15 HIDDEN GLEN DUMP REMEDIATION
DRAWN BY:

DESIGNED BY:

CHECKED BY:

BS
MR
DATE
DATE
DATE
DATE:

CAD FILE:

DRAWING NO.

SHEET NO. OF
VERT.

RH/OP 10/14/24
5/22/24
5/22/24
OCTOBER 14, 2024

FINAL GRADING PLAN
0 feet 20
1" = 20'
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ATTACHMENT 6
0' 5' 10' 15' 20' 25' 30' 35' 40' 45' 50' 55' 60' 65' 70' 75' 80' 85' 90' 95' 100' 105'
110'
115'
120'
125'
130'
135'
0' 5' 10' 15' 20' 25' 30' 35' 40' 45' 50' 55' 60' 65' 70' 75' 80' 85' 90' 95' 100' 105'
110'
115'
120'
125'
130'
135'
EX. CURB
EX. ROAD
(PASCALE PLACE)
EX. CURB
EX. ROAD
(PASCALE PLACE)
LOT 12
105'
130'
140'
135'
145'
125'
150'
155'
120'
115'
-5'
-5'
-230' -225' -220' -215' -210' -205' -200' -195' -190' -185' -180' -175' -170' -165' -160' -155' -150' -145' -140' -135' -130' -125' -120' -115' -110' -105' -100' -95' -85'-90' -80' -75' -65'-70' -60' -55' -45'-50' -40' -35' -25'-30' -20' -15' -10' -5' 0' 5' LOT 9
140'
135'
130'
125'
120'
0' 5' 10' 15' 20' 25' 30'
LOT 9
140'
135'
130'
125'
120'
-5' 0' 5' 10' 15' 20' 25' 30'
LOT 9
130'
125'
120'
115'
110'
0' 5' 10' 15' 20' 25' 30' 0' 5' 10' 15' 20'
115'
125'
135'
120'
130'
LOT 7
35' 40' 45'
2% MIN SLOPE
3 1
-5' -20' -15' -10' -5'
-10' -5'
0' 5' 10' 15' 25'20' 30'
125'
130'
135'
140'
145'
145'
LOT 10
-10' -5'
-10'

PROPOSED GRADE

PROPERTY LINE

REMOVE EXISTING SOIL WITH
WASTE. FILL WITH CLEAN SOIL

TO PROVIDE POSITIVE
DRAINAGE.

EX. BEDROCK

PROPERTY LINE

PROPERTY LINE

PROPERTY LINE
REMOVE EXISTING SOIL WITH WASTE.

FILL WITH CLEAN SOIL TO PROVIDE
EX. FENCE POSITIVE DRAINAGE
EX. BOULDER
EX. GALVANIZED

STEEL FENCE

APPROXIMATE LIMIT OF

LANDFILL CAP APPROXIMATE LIMIT OF

LANDFILL CAP

APPROXIMATE LIMIT OF

LANDFILL CAP

PROPOSED GRADE
EX. BED ROCK
EX. TREE
EX. FENCE

SOIL WITH WASTE
EX. GRADE

PROPOSED GRADE
EX. BED ROCK
EX. PROPERTY LINE

REMOVE EXISTING SOIL WITH
WASTE. FILL WITH CLEAN SOIL

TO PROVIDE POSITIVE

DRAINAGE

PROPOSED GRADE
EX. GRADE
EX. PROPERTY
LINE

SOIL WITH WASTE
EX. BED ROCK
EX. TOP SOIL
EX. WASTE
EX. GEOCOMPOSITE

DRAINAGE NET &

POLYETHYLENE

MEMBRANE
EX. FOUNDATION
FILL (24")
EX. GRADE
EX. TOP SOIL
EX. GEOCOMPOSITE

DRAINAGE NET &

POLYETHYLENE MEMBRANE
EX. WASTE
EX. FOUNDATION
FILL (18" MIN.)
EX. GEOCOMPOSITE

DRAINAGE NET &

POLYETHYLENE MEMBRANE
EX. WASTE
EX. FOUNDATION
FILL (18" MIN.)
EX. BED ROCK
EX. GRADE

FINISHED GRADE
EX. BED ROCK
EX. GRADE

FINISHED GRADE

APPROXIMATE LIMIT OF

LANDFILL CAP

PROPERTY LINE
EX. GRADE
EX. BEDROCK
EX. GEOCOMPOSITE DRAINAGE NET
& POLYETHYLENE MEMBRANE
EX. TOP SOIL
EX. WASTE
EX. FOUNDATION FILL (18" MIN.)

SOIL WITH WASTE FILL,

SEE PLAN FOR DEPTH
2'-0" MIN. OF SOIL CAP
REMOVE EXISTING SOIL WITH WASTE. FILL

WITH CLEAN SOIL TO PROVIDE POSITIVE

DRAINAGE
EX. PROPERTY LINE

APPROXIMATE LIMIT OF

LANDFILL CAP

SOIL WITH DEBRIS
EX. GRADE
EX. BED ROCK
PROP. GRADE
REMOVE EXISTING SOIL WITH WASTE. FILL WITH

CLEAN SOIL TO PROVIDE POSITIVE DRAINAGE

FINISHED GRADE
EX. GRADE
EX. GEOCOMPOSITE

DRAINAGE NET &

POLYETHYLENE MEMBRANE
EX. WASTE
EX. FOUNDATION FILL
(18" MIN.)

REMOVE EXISTING SOIL WITH
WASTE. FILL WITH CLEAN SOIL

TO PROVIDE POSITIVE

DRAINAGE
SWALE
11 T:\Projects\2017 Projects\17058_HiddenGlenPark\3_ConstructionDocuments\A17058_GD.dwg NO.

REVISIONS

DESCRIPTION
DESCRIPTION:

ELEV.

BENCH MARK

DATE BY
HORIZ.

SCALE
15 HIDDEN GLEN DUMP REMEDIATION DRAWN BY:

DESIGNED BY:

CHECKED BY:

BS
MR
DATE
DATE
DATE
SHEET NO.

DRAWING NO.

CAD FILE:

DATE:

OF
VERT.

RH/OP
5/22/24
10/14/24
5/22/24
OCTOBER 14, 2024

5.1 GRADING SECTIONS
A17058_GD.dwg
I
\ -1 - -- - __ .;c-;- , -• c,1 u--=. =n_i:;=1 1;;. - -- I ~ I --- -- II )I N If V -- - - I ,, ' \ \\ • ' \\ ,, // - - -- -- --- --- L r,, - 'i. II - )I " ' 's ~
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@SECTION1 5.1 SECTION vEROOAL SCALE: 1"-10' HORIZCWTAL SCALE: 1"-10' ~ SECTION2 ~ SECTION VERTICAL SCALE: 1"-10' HORIZONTAL SCALE: f-10' @SECTION3

5.1 SECTION VERTICAL SCALE: 1"-10' HORIZONTAL SCALE: 1"-10' \ I - 371;:- - - - . T ---- - - -- - - - - ( - - -- - - - ' I ---- ---_.,,- _fi, _l - -
{ " ~\ - - - l IN
- - " ('( - -
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@SECTION4 5.1 SECTION VERTICAL SCALE: 1"-10' HORIZCWT AL SCALE: 1"-10' @SECTIONS L5.1 SECTION VERTICAL SCALE: 1"-10' HORIZONTAL SCALE: f-10' @SECTIONS 5.1 SECTION VERTICAL SCALE: 1"-10' HORIZONTAL SCALE: 1"-10' ·4-t--r",-,°'==; ' \
~ I
\ \_ - '\---,--f-_/-1 LJ
\ \
@SECTIONS

5.1 SECTION VERTICAL SCALE: 1"-10' HORIZONTAL SCALE: 1"-10' @SECTION7 5.1 SECTION VERTICAL SCALE: 1"-10' HORIZCWT AL SCALE: 1"-10' 11711 ~,O T1ibui_my Po'nil D11iv,e Gold Rlve" 9'5570
Ctl,IJl, ?rcje::lt N-rl 17G58A

UTILITIES DEPARTMENT

110'
115'
120'
130'
125'
LOT 5
0' 5' 10' 15' 25'20' 30' 35' 45'40'
LOT 6 140'
135'
130'
125'
120'
0' 5' 10' 15' 20' 25' 30' 35' 40' 45'
0' 5' 10' 15' 20' 25' 30' 35' 50'45'40'
125'
130'
135'
140'
145' LOT 6
0' 5' 10' 15' 20' 30'25' 40'35' 50'45'
120'
125'
130'
135'
140' LOT 6
0' 5' 10' 15' 20' 30'25' 40'35' 50'45' 55'
115'
120'
125'
130'
135' LOT 5
2'-0" FROM

PROPERTY LINE
-15' -10' -5' -5'
-10' -5'
-10' -5'
-10' -5'
140'
135'
130'
125'
120'
-20' -15' -10' -5' 0' 5' 10' 15' 20'
LOT 9
EX. FENCE

PROPOSED GRADE

PROPOSED WALL & FENCE
SWALE

PROPERTY LINE

PROPERTY LINE

GEOCOMPOSITE

DRAINAGE NET

APPROXIMATE LIMIT OF

LANDFILL CAP

APPROXIMATE LIMIT OF

LANDFILL CAP

APPROXIMATE LOCATION

OF EXISTING DECK

SOIL WITH WASTE
EX. BED ROCK
EX. PROPERTY LINE
EX. WALL
EX. TREE (HAND DIG TO

EXCAVATE DEBRIS)
EX. FENCE

PROPOSED GRADE
EX. GRADE
EX. SHRUB

SOIL WITH WASTE
REMOVE EXISTING SOIL WITH WASTE. FILL WITH

CLEAN SOIL TO PROVIDE POSITIVE DRAINAGE
EX. BEDROCK
EX. GRADE
EX. TOP SOIL
EX. WASTE
EX. GEOCOMPOSITE

DRAINAGE NET &

POLYETHYLENE MEMBRANE
EX. FOUNDATION
FILL (18" MIN.)
EX. TOP SOIL
EX. WASTE
EX. GEOCOMPOSITE DRAINAGE

NET & POLYETHYLENE MEMBRANE
EX. FOUNDATION
FILL (18" MIN.)
EX. TOP SOIL
EX. WASTE
EX. GEOCOMPOSITE DRAINAGE

NET & POLYETHYLENE

MEMBRANE
EX. FOUNDATION
FILL (18" MIN.)
EX. TOP SOIL
EX. WASTE
EX. GEOCOMPOSITE

DRAINAGE NET &

POLYETHYLENE MEMBRANE
EX. FOUNDATION FILL
(18" MIN.)
EX. FENCE EX. GRADE
EX. DECK IN APPROXIMATE LOCATION

PROPERTY LINE

SOIL WITH WASTE
REMOVE EXISTING SOIL WITH WASTE. FILL

WITH CLEAN SOIL TO PROVIDE POSITIVE
DRAINAGE.
1'-0" MIN. SOIL LAYER FILL SOIL TO

PROVIDE POSITIVE DRAINAGE

REMOVE EXISTING SOIL WITH
WASTE. FILL WITH CLEAN SOIL TO

PROVIDE POSITIVE DRAINAGE
REMOVE EXISTING SOIL WITH WASTE. FILL WITH

CLEAN SOIL TO PROVIDE POSITIVE DRAINAGE
1'-0" MIN. SOIL LAYER, FILL

SOIL TO PROVIDE POSITIVE

DRAINAGE
1'-0" MIN. SOIL LAYER, FILL

SOIL TO PROVIDE POSITIVE

DRAINAGE

REMOVE AND REPLACE EXISTING
RIPRAP WITH NORMAL 3" CRUSHED
ROCK, 1' THICK AND EXTENDING 6"

ABOVE THE TOP PF THE DRAINAGE PIPE
NORMAL 12" RIP

RAP MINIMUM
2-FT THICKNESS

APPROXIMATE LIMIT OF

PROPERTY LINE LANDFILL CAP
EX. 4-INCH SOLID

CORRUGATED HDPE PIPE
EX. 4-INCH PERFORATED CORRUGATED

DRAINAGE PIPE LOCATED AT END OF

GEOCOMPOSITE DRAINAGE NET
EX. FENCE
1'-0" MIN. SOIL LAYER, FILL SOIL

TO PROVIDE POSITIVE

DRAINAGE
1'-0" MIN. SOIL LAYER, FILL

SOIL TO PROVIDE POSITIVE

DRAINAGE
EX. BEDROCK

PROPERTY LINE
EX. BED ROCK
EX. FENCE EX. GRADE
EX. TOP SOIL
EX. WASTE
EX. GEOCOMPOSITE DRAINAGE NET
& POLYETHYLENE MEMBRANE
EX. FOUNDATION
FILL (18" MIN.)
EX. NEW LAYER OF SOIL WITH DEBRIS
REMOVE EXISTING SOIL WITH WASTE TO BEDROCK. FILL

WITH CLEAN SOIL TO PROVIDE POSITIVE DRAINAGE

APPROXIMATE LIMIT OF

LANDFILL CAP
2'-0" FROM

PROPERTY LINE
2% MIN
2% MIN
2% MIN
2% MIN
12 T:\Projects\2017 Projects\17058_HiddenGlenPark\3_ConstructionDocuments\A17058_GD.dwg NO.

REVISIONS

DESCRIPTION
DESCRIPTION:

ELEV.

BENCH MARK

DATE BY
HORIZ.

SCALE
15 HIDDEN GLEN DUMP REMEDIATION DRAWN BY:

DESIGNED BY:

CHECKED BY:

BS
MR
DATE
DATE
DATE
SHEET NO.

DRAWING NO.

CAD FILE:

DATE:

OF
VERT.

RH/OP
5/22/24
10/14/24
5/22/24
OCTOBER 14, 2024

5.2 GRADING SECTIONS
A17058_GD.dwg
@SECTION1 5.2 SECTlON vB1flCAL SCALE: 1"-10' HOIIZONTAL SCALE: 1"-10' @SECTION2

5.2 SECT'DI VERTICAL SCALE: 1"-10' HORIZONTAL SCALE: 1"-10' LLi SECTION 3 \_[,V SECTlON vB1TICAL SCALE: 1"-10' HOIIZONTAL SCALE: 1"-10' @SECTION4

5.2 SECT'DI VERTICAL SCALE: 1"-10' HORIZONTAL SCALE: 1"-10' \
I ,~~~L--~~-l--- -- - ----,_
LLi SECTION 5 \_[,V SECTlON vB1TICAL SCALE: 1"-10' HOIIZONTAL SCALE: 1"-10' 11711 ~,O T1ibui.my Po'nil D11iv,e
Gold Rlve" 9'5570
Ctl,IJl, ?rcje::lt N,r1 17G58A

UTILITIES DEPARTMENT

W
W
N50° 43' 20"W

79.84'
L=18.12, R=32.00 Δ=32°26'37" N83° 10' 01"W

16.20'
N83° 10' 01"W
132.99' N73° 05' 03"W 67.99'
N16° 55' 11"E 58.30'
N16° 55' 11"E 327.88'
N68° 18' 22"W

24.07'
N70° 12' 09"W

18.42'
N65° 49' 13"W

54.38'
N36° 31' 56"W

25.19'
N12° 57' 00"W

29.06'
N41° 22' 49"W

25.60'
N62° 33' 25"W

22.11'
N73° 13' 30"E 20.26'
N67° 08' 28"W

71.16'
N22° 05' 10"W

59.78'
N14° 04' 43"E

49.82'
N14° 04' 43"E
115.50'
N14° 04' 43"E
141.38'
N41° 16' 44"E N74° 27' 57"W 42.29'
N37° 05' 54"E 42.14'
N11° 52' 43"E

35.16'
N48° 46' 49"E 77.69'
N66° 25' 41"W
120.04'
134
135
136
133
132
131
130
129
128
127
126
125
130
129
128
127
126
125 131
7 5.3
LOT 12
155'
150'
145'
140'
135'
130'
125'
120'
115'
0' 5' -5' -10' -20' -15' -25' -30' -40' -35' -45' -50' -60' -55' -65' -70' -80' -75' -85' -90' -100' -95' -105' -110' -120' -115' -125' -130' -140' -135' -145' -150' -160' -155' -165' -170' -180' -175' -185' -190' -200' -195' -205' -210' -220' -215' -225' -230' 2% MIN SLOPE

APPROXIMATE LIMIT OF

LANDFILL CAP

PROPERTY LINE
EX. GRADE
EX. BEDROCK
EX. GEOCOMPOSITE DRAINAGE NET
& POLYETHYLENE MEMBRANE
EX. TOP SOIL
EX. WASTE
EX. FOUNDATION FILL (18" MIN.)
1'-0" MIN. OF SOIL CAP

SOIL COVER MATERIAL

SECTION CUT

SOIL REMEDIATION PILE CONTOUR
EXISTING CONTOUR: 1'-0" INTERVAL TYP.

PROPOSED CONTOUR: 1'-0" INTERVAL TYP.

PROPOSED SPOT ELEVATION (EXISTING SPOT ELEVATIONS ARE SCREENED ON PLAN)

DIRECTION AND PERCENT SLOPE OF SHEET DRAINAGE
SWALE WITH MIN. 2% SLOPE

GRADE BREAK

FLUSH CONDITION

CONTROL POINT

HIGH POINT

TOP OF CURB

BOTTOM OF CURB

TOP OF WALL

BOTTOM OF WALL

TOP OF RAMP

BOTTOM OF RAMP

RIM ELEVATION OF DRAIN INLET, SEE WALL AND DRAINAGE PLAN VERTICAL CURVE PER CHP HIGHWAY DESIGN MANUAL SECTION 200-24

BEGINNING OF VERTICAL CURVE

END OF VERTICAL CURVE

GRADE BREAK
X%
GB

GRADING AND DRAINAGE NOTES

1. GRADING AND DRAINAGE: ALL PROPOSED PAVING, CURBS, WALLS, AND PLANTING AREAS SHALL SMOOTHLY CONFORM TO EXISTING ADJACENT FEATURES TO REMAIN. PROVIDE POSITIVE DRAINAGE ON ALL PAVING AND THROUGHOUT ALL PLANTING AREAS.

2. SOIL STOCKPILE: STRIP AND STOCKPILE EXISTING 6" LAYER OF SOIL FROM AREAS DISTURBED DURING GRADING OR EXCAVATION.

3. GRADING: CONTRACTOR SHALL PERFORM ALL EARTHWORK AND GRADING PER GEOTECHNICAL ENGINEER'S RECOMMENDATIONS.

4. LANDFILL CAP PROTECTION: REFER TO SPECIAL PROVISIONS SECTION 00 72 00 GENERAL REQUIREMENTS, SECTION 1.3.C FOR LANDFILL CAP PROTECTION REQUIREMENTS.

HP
TC
BC
TW
BW
TR
BR
RIM
VC
BVC
EVC
GB
X
XX
XXX
XX
XX.XX
13 5.3
A17058_GD.dwg T:\Projects\2017 Projects\17058_HiddenGlenPark\3_ConstructionDocuments\A17058_GD.dwg NO.

REVISIONS
DESCRIPTION ELEV.

DESCRIPTION:

BENCH MARK

DATE BY
HORIZ.

SCALE
15 HIDDEN GLEN DUMP REMEDIATION
DRAWN BY:

DESIGNED BY:

CHECKED BY:

BS
MR
DATE
DATE
DATE
DATE:

CAD FILE:

DRAWING NO.

SHEET NO. OF
VERT.

RH/OP 10/14/24
5/22/24
5/22/24
OCTOBER 14, 2024

GRADING PLAN - ADD ALTERNATE
0 feet 20
1" = 20'
40 NORTH
7 5.3
SECTION 1
SECTION VERTICAL SCALE: 1"=5' HORIZONTAL SCALE: 1"=5'
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ATTACHMENT 6

GEOTEXTILE FABRIC

RIP RAP, REUSE EXISTING PER FINISH GRADE

DEMOLITION PLANS, OR VIRGIN

MATERIAL TO MATCH EXISTING RIP
RAP ON SITE. LIMITS PER PLANTING
PLAN. 8" MIN. DEPTH.

FINISH GRADE
6 RIP RAP

6.0 1 1/2" = 1'-0" 17058_RipRap.dwg
2 EDGE TREATMENT TYPE 3 - SOIL FILL SWALE

6.0 1/4" = 1'-0" A17058_EdgeTreatmentType2_48.dwg
EXCAVATE 2'-0" MAX OF EX. DEBRIS. FILL

AND GRADE TO DRAIN TO SWALE OR ON
PARK SIDE OF PROPERTY LINE.

PROPERTY LINE
EX. GRADE,
SEE PLANS.

FINISH GRADE
LOT X
SWALE
EX. DEBRIS
4'-0" FROM EXISTING FENCE,
1'-0" MIN. AT TOE OF CUT
1 EDGE TREATMENT TYPE 1 - SOIL FILL GRADE TO DRAIN

6.0 1/4" = 1'-0" A17058_EdgeTreatmentType1_48.dwg
LOT "X"
EX. GRADE, SEE PLANS.

PROPERTY LINE

FINISH GRADE, GRADE

TO DRAIN AWAY FROM
NEIGHBORING LOTS.

SOIL FILL SLOPE AGAINST

PROPERTY LINE
EX. DEBRIS
4'-0" FROM EXISTING FENCE,
1'-0" MIN. AT TOE OF CUT
7 6.0

SWALE SLOPE
MIN: 2%
MAX 33%
SWALE TYP.

SWALE FLOWLINE:

LOCATED PER PLAN
NOTES:

1. SALE TO HAVE MINIMUM 2% LONGITUDINAL SLOPE. CONTRACTOR SHALL ENSURE POSITIVE DRAINAGE TOWARD OUTFALL DESIGNATED ON PLANS.

NOTE:

1. SOIL COVER SHALL BE MIN 5% TO 33% MAX FOR SITE DRAINAGE 4 6.0 1/8" = 1'-0" CLIFF TYP.dwg
CLIFF TYP.

MIN 2' DEPTH
COVER

APPROXIMATE LIMIT

OF LANDFILL CAP

PROPERTY LINE
EX. BEDROCK

1.8'-2' DEPTH OF
DEBRIS

OPTIONAL MORE

DEBRIS LAYER
2' DEPTH OF

SOIL COVER
EX. SOIL
EX. DEBRIS
EX. GEOCOMPOSITE DRAINAGE

NET & POLYETHYLENE MEMBRANE
EX. TOP SOIL
3 EDGE TREATMENT TYPE 6 - SOIL FILL OVER PROP. LINE

6.0 1/4" = 1'-0" A17058_EdgeTreatmentType6_48.dwg

GRADE TO
DRAIN
EX. GRADE,
SEE PLANS.

PROPERTY LINE

FINISH GRADE, GRADE

TO DRAIN AWAY FROM
NEIGHBORING LOTS.

LOT "X"

CLEAN SOIL FILL

OVER PROPERTY
LINE

EXISTING DEBRIS

BEDROCK

APPROXIMATE LIMIT

OF LANDFIL CAP
4'-0" FROM EXISTING FENCE,
1'-0" MIN. AT TOE OF CUT
5 EDGE TREATMENT - RIP RAP

6.0 1/4" = 1'-0" A17058_EdgeTreatmentType8_48.dwg

ADDITIONAL
6" RIP RAP
EX. RIP
RAP

FILL SOIL

APPROXIMATE LIMIT

OF LANDFILL CAP

PROPERTY
LINE
EX. FENCE
FINISH
GRADE
EX. BED ROCK EX. DEBRIS
EX. GRADE,
SEE PLANS.

EX. FOUNDATION FILL

GEOCOMPOSITE

DRAINAGE NET &

POLYETHYLENE MEMBRANE
EX. TOP SOIL
EX. 4-INCH PERFORATED CORRUGATED

DRAINAGE PIPE LOCATED AT END OF
GEOCOMPOSITE DRAINAGE NET.

EX. 4-INCH SOLID

CORRUGATED

HDPE PIPE
8 MONITOR WELL WITH PRECAST MANHOLE

6.0 1/2" = 1'-0" A17058_EdgeTreatmentType1_48.dwg

ROUND MANHOLE
STEEL VAULT, 24" X 24",
PER SPECS 2'-0"
CONCRETE COLLAR: 9" WIDE BY 6"
DEEP. WITH HORIZONTAL
REINFORCEMENT #3 REBAR CONT.

EXISTING MONITOR WELL AND PAD.

CUT STEEL MONUMENT BELOW GRADE

AND INSTALL PVC CASING IN A FLUSH

TO GRADE WELLBOX WITH CONCRETE
PAD AROUND AT PROP. GRADE

FINISH GRADE
EX. GRADE GRADE
EX. SOIL WITH WASTE
EX. BEDROCK T:\Projects\2017 Projects\17058_HiddenGlenPark\3_ConstructionDocuments\A17058_DT.dwg NO.

REVISIONS

DESCRIPTION
DESCRIPTION:

ELEV.

BENCH MARK

DATE BY
HORIZ.

SCALE
15 HIDDEN GLEN DUMP REMEDIATION DRAWN BY:

DESIGNED BY:

CHECKED BY:

BS
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DATE
DATE
DATE
SHEET NO.

DRAWING NO.

CAD FILE:

DATE:

OF
VERT.

RH/OP
5/22/24
10/14/24
5/22/24
OCTOBER 14, 2024

6.0 CONSTRUCTION DETAILS
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Control Point Table (NAD83 Coordinates)
Point# Raw Description Northing Easting
10 FND_BD IN WELL 1870569.56 6485054.72
I I FND_BD IN WELL 1870245.72 6484973.50
12 FND_BD IN WELL 1870157.47 6485225.09
501 FND_JP LS45l0 1870378.90 6485092.54
508 FND_JP LS45/0 1870359.39 6485/00.44
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LEGEND

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IP IRON PIPE
NOTES:

Property fines shown here are based on Subdivision Map
fifed in Book 23 Page 82 in the offices of Napa County
Recorder
40 I
Topographic mapping was prepared by photogrammetric
methods, photo date 5- 11-2023, and supplemented by field SUNey.

BASIS OF BEARINGS
NAD83, ZONE IU, EPOCH 2008.00 CALIBRATED ON CITY OF
NAPA POINTS 43, 47, AND 51 AS SHOWN ON RECORD O F
SURVEY BOOK 41 OF SURVEYS AT PAGES 44-47, N.C.R.

THE BEARINGS SHOWN ON THIS EXHIBIT HAVE BEEN ROTATED
TO NAO '83. ROTATE NAD '83 BEARINGS 00° 07' 52"
CLOCKWISE TO OBTAIN RECORD BEARINGS.

THIS MAP WAS PREPARED BY M E OR UNDER MY DIRECTION
SUDHIR K. C HAUDHARY, PLS 8993 DATE
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COUNTY DRAWI NG FILE #
0----------------------------------------------------------------------------------------------------------------------------------------------------- Page 179 of 342 ATTACHMENT 6 Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024

APPENDIX D
Geotechnical Laboratory Testing

APPENDIX C
2018 Langan Soil Results

!.
!.
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Parcel No. 6
APN: 045411025000
Glory
Court
L6-B-27
L6-B-28
L6-B-26
L6-B-25
L6-B-24
L6-B-22
L6-B-23
L6-B-19
L6-B-20
L6-B-21
L6-B-16
L6-B-17
L6-B-18
L6-B-14
L6-B-15
L6-B-12
L6-B-13
L6-B-10
L6-B-11
L6-B-09
L6-B-07
L6-B-08
L6-B-06
L6-B-04
L6-B-05
L6-B-02
L6-B-03
L6-B-01
139
138
137
135
134
133
132
131
130
129
126
125
124
123
122
1 121
20 11
1 6
15 11
11 3
11 2
11 1
1 0
0 1
9 08
10 1
7 0
1 6
05 103
102
101
118
117
114
13 1
1 30
122
121
120
126
125
136
128
127
119
104
151
141
135
130
129
128
128
126
125
100
128
128
Date 4/23/2019 Project 750649501
\\langan.com\data\OAK\data5\750649501\Project Data\ArcGIS\MXD\Environmental_Figures\Discrete Sampling Figures_April 2019\Lot Specific Report Figures\Lot 6 Haz Waste.mxd User: bsaylor FORMER HIDDEN GLEN LANDFILL INVESTIGATION Napa, California LOT 6 - SITE PLAN

WITH APPROXIMATE SOIL SAMPLE LOCATIONS

EXCEEDING CLASS I NON-RCRA STATE OF

CALIFORNIA HAZARDOUS WASTE CRITERIA

AND RESIDENTIAL ESL FOR LEAD
Figure 2
q Soil Sampling Analytical Results Sample ID L6COMP1 L6B 10 L6B18 L6B19 L6B24 Residential ESLs  Cancer Risk 1 Residential ESLs
 NonCancer
Hazard
1 TTLC2
(mg/kg)
STLC
2 (mg/L)
TCLP
2 (mg/L)
Total Lead (mg/kg) 140 100 300 75 67 82 80 1,000  
STLC (mg/L) 9.0 0.87 0.27 35 0.89    5 
TCLP (mg/L) 0.22 0.021 < 0.5 1.5      5
Legend
!.

Discrete Soil Sample Collected for Four-Point Composite Laboratory Analytical Sample (L6-COMP-1) Approximate Location of Soil BoringAdvanced by Langan, December 2018Approximate Extent of Former Hidden Glenn LandfillLidar Contour - 1ft. IntervalSoil Borings on 15 ft. CentersFormer Hidden Glenn Landfill Buffer - 10 ft.Approximate Location of Soil Sample Exceeding Class I non-RCRA State of California Hazardous Waste CriteriaApproximate Location of Soil SampleExceeding Residential ESL for LeadAssessor's Parcel Boundaries 0 10 20 40
Feet
Notes:1. San Francisco Bay Regional Water Quality Control Board (RWQCB), Direct Exposure Human Health Risk Levels (Table S-1), Soil Residential: Shallow Soil Exposure, Cancer Risk and Non-Cancer Hazard Environmental Screening Levels, dated January 2019. 2. Hazardous Waste Criteria 3. Bold concentration exceeds the lower of the Cancer Risk or Non-Cancer Risk ESLs. 4. Bold Italicized - concentration exceeds hazardous waste criteria. 5. TTLC - California Total Threshold Limit Concentration - State hazardous waste criterion

6. STLC - California Soluble Threshold Limit Concentration 7. TCLP - Federal Toxicity Characteristic Leaching Procedure 8. World aerial imagery basemap is provided through Langan’s Esri ArcGIS software licensing and ArcGIS online. Credits: Esri, DigitalGlobe, GeoEye, i-cubed, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, and the GIS User Community. 9. All features shown are approximate. 10. Site boundary provided by the Napa County parcel dataset, 2016. 11. LiDAR survey data for the northern San Francisco Bay, CA provided by National Oceanic and Atmospheric Administration (NOAA) with accuracy of 1 meter, updated 2010. •
CJ
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LANliAN

ATTACHMENT 6
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Parcel No. 9
APN: 045411021000
Pascale Place L9-B-36 L9-B-37 L9-B-38 L9-B-34 L9-B-35 L9-B-31 L9-B-32 L9-B-33 L9-B-27 L9-B-29
L9-B-30
L9-B-25
L9-B-26
L9-B-28
L9-B-23
L9-B-24
L9-B-21
L9-B-20
L9-B-22 L9-B-18
L9-B-19
L9-B-15
L9-B-17
L9-B-13
L9-B-14
L9-B-16 L9-B-11
L9-B-12
L9-B-10
L9-B-08
L9-B-09
L9-B-06
L9-B-07
L9-B-05
L9-B-03
L9-B-04
L9-B-01
L9-B-02
133
132
131
130
129
128
127
126
122
121
120
119
118
117
116
115
114
111
110
109
108
107
106
105
104
103
102
13 1
7 36
135
143
142
141
140
139
138
128
127
112
111
134
125
124
123
113
144
137
128
123
121
113
106
101
Date 4/30/2019 Project 750649501
0 10 20 40
Feet
\\langan.com\data\OAK\data5\750649501\Project Data\ArcGIS\MXD\Environmental_Figures\Discrete Sampling Figures_April 2019\Lot Specific Report Figures\Lot 9 Haz Waste.mxd User: ogodfrey FORMER HIDDEN GLEN LANDFILL INVESTIGATION Napa, California LOT 9 - SITE PLAN

WITH APPROXIMATE SOIL SAMPLE LOCATIONS

EXCEEDING CLASS I NON-RCRA STATE OF

CALIFORNIA HAZARDOUS WASTE CRITERIA

AND RESIDENTIAL ESL FOR LEAD
Figure 2
q Soil Sampling Analytical Results Sample ID Total Lead (mg/kg) STLC (mg/L) TCLP (mg/L) L9-COMP-1 270 5.5 0.080
L9-B-04 67 1.4 -- L9-B-09 240 5.6 0.20 L9-B-13 2700 4.9 0.13 L9-B-30 200 9.3 0.47 L9-COMP-2 63 3.0 --
L9-B-02 66 1.2 -- L9-B-16 200 2.6 0.032 L9-B-29 100 3.5 0.029 L9-B-35 67 0.19 -- Residential ESLs - Cancer Risk
1 82 -- --
Residential ESLs - Non-Cancer Hazard
1 80 -- --
TTLC2 (mg/kg) 1,000 -- --
STLC2 (mg/L) -- 5 -- TCLP2 (mg/L) -- -- 5
Notes:1. San Francisco Bay Regional Water Quality Control Board (RWQCB), Direct Exposure Human Health Risk Levels (Table S-1), Soil Residential: Shallow Soil Exposure, Cancer Risk and Non-Cancer Hazard Environmental Screening Levels, dated January 2019. 2. Hazardous Waste Criteria 3. Bold concentration exceeds the lower of the Cancer Risk or Non-Cancer Risk ESLs. 4. Bold Italicized - concentration exceeds hazardous waste criteria. 5. TTLC - California Total Threshold Limit Concentration - State hazardous waste criterion

6. STLC - California Soluble Threshold Limit Concentration 7. TCLP - Federal Toxicity Characteristic Leaching Procedure 8. World aerial imagery basemap is provided through Langan’s Esri ArcGIS software licensing and ArcGIS online. Credits: Esri, DigitalGlobe, GeoEye, i-cubed, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, and the GIS User Community. 9. All features shown are approximate. 10. Site boundary provided by the Napa County parcel dataset, 2016. 11. LiDAR survey data for the northern San Francisco Bay, CA provided by National Oceanic and Atmospheric Administration (NOAA) with accuracy of 1 meter, updated 2010.

Legend
Approximate Location of Soil BoringAdvanced by Langan, December 2018 !.

Discrete Soil Sample Collected for Four-Point Composite Laboratory Analytical Sample (L9-COMP-1 & L9-COMP-2)Approximate Extent of Former Hidden Glenn LandfillLidar Contour - 1ft. IntervalSoil Borings on 15 ft. CentersFormer Hidden Glenn Landfill Buffer - 10 ft.Approximate Location of Soil Sample Exceeding Class I non-RCRA State of California Hazardous Waste Criteriaand Residential ESL for LeadApproximate Location of Soil SampleExceeding Residential ESL for LeadAssessor's Parcel Boundaries •
CJ
-
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LAN6AN

ATTACHMENT 6
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Parcel No. 8
APN: 045411023000
Parcel No. 7
APN: 045411024000
Pascale Place
Glory
Court
L7-B-28
L7-B-29
L7-B-27
L7-B-26
L7-B-24
L7-B-25
L7-B-23
L7-B-21
L7-B-22
L7-B-19
L7-B-20
L7-B-18
L7-B-16
L7-B-17
L7-B-13
L7-B-14
L7-B-15
L7-B-12
L7-B-10
L7-B-11
L7-B-08
L7-B-09
L7-B-06
L7-B-07
L7-B-04
L7-B-05
L7-B-03
L7-B-02
L7-B-01
L8-B-36
L8-B-35
L8-B-32
L8-B-33
L8-B-34
L8-B-31
L8-B-29
L8-B-30
L8-B-26
L8-B-27
L8-B-28
L8-B-25
L8-B-23
L8-B-24
L8-B-21
L8-B-22
L8-B-19
L8-B-20
L8-B-17
L8-B-18
L8-B-16
L8-B-14
L8-B-15
L8-B-11
L8-B-12
L8-B-13
L8-B-10
L8-B-08
L8-B-09
L8-B-06
L8-B-07
L8-B-04
L8-B-05
L8-B-02
L8-B-03
L8-B-01
13 1
5 33
132
131
127
12 1
6 25
124
122
121
119
118
11 1
7 16
115
114
113
1 1
12 11
110
109
108
106
104
103
102
10 1
1 0
9 0
9 98
97 137
136
134
130
129
128
123
95 94
91 90
97 96
95 94
93 92
99 98
138
120
107
105
96 93
129
130
128
127
125
105
99 97
89 128
Date 4/30/2019 Project 750649501
0 12.5 25 50
Feet
\\langan.com\data\OAK\data5\750649501\Project Data\ArcGIS\MXD\Environmental_Figures\Discrete Sampling Figures_April 2019\Lot Specific Report Figures\Lot 7 8 Haz Waste.mxd User: ogodfrey FORMER HIDDEN GLEN LANDFILL INVESTIGATION Napa, California LOT 7 AND 8 - SITE PLAN

WITH APPROXIMATE SOIL SAMPLE LOCATIONS

EXCEEDING CLASS I NON-RCRA STATE OF

CALIFORNIA HAZARDOUS WASTE CRITERIA

AND RESIDENTIAL ESL FOR LEAD
Figure 2
q Soil Sampling Analytical Results Sample ID Total Lead (mg/kg) STLC (mg/L) TCLP (mg/L) Lot 7
L7-COMP-1 520 17 0.096
L7-B-22 210 14 0.11 L7-B-23 250 17 0.044 L7-B-25 890 33 0.088 L7-B-28 750 21 0.076 L7-COMP-2 25 -- --
L7-B-02 11 -- -- L7-B-09 43 -- -- L7-B-12 54 0.59 -- L7-B-13 90 1.8 -- Lot 8
L8-COMP-1 100 2.6 0.082
L8-B-07 240 5.9 0.081 L8-B-15 320 12 0.15 L8-B-18 54 0.49 -- L8-B-21 23 -- -- L8-COMP-2 36 -- --
L8-B-25 18 -- -- L8-B-28 26 -- -- L8-B-34 21 -- -- L8-B-36 83 1.5 -- Residential ESLs - Cancer Risk
1 82 -- --
Residential ESLs - Non-Cancer Hazard
1 80 -- --
TTLC2 (mg/kg) 1,000 -- --
STLC2 (mg/L) -- 5 -- TCLP2 (mg/L) -- -- 5
Notes:1. San Francisco Bay Regional Water Quality Control Board (RWQCB), Direct Exposure Human Health Risk Levels (Table S-1), Soil Residential: Shallow Soil Exposure, Cancer Risk and Non-Cancer Hazard Environmental Screening Levels, dated January 2019. 2. Hazardous Waste Criteria 3. Bold concentration exceeds the lower of the Cancer Risk or Non-Cancer Risk ESLs. 4. Bold Italicized - concentration exceeds hazardous waste criteria. 5. TTLC - California Total Threshold Limit Concentration - State hazardous waste criterion

6. STLC - California Soluble Threshold Limit Concentration 7. TCLP - Federal Toxicity Characteristic Leaching Procedure 8. World aerial imagery basemap is provided through Langan’s Esri ArcGIS software licensing and ArcGIS online. Credits: Esri, DigitalGlobe, GeoEye, i-cubed, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, and the GIS User Community. 9. All features shown are approximate. 10. Site boundary provided by the Napa County parcel dataset, 2016. 11. LiDAR survey data for the northern San Francisco Bay, CA provided by National Oceanic and Atmospheric Administration (NOAA) with accuracy of 1 meter, updated 2010.

Legend
Approximate Location of Soil BoringAdvanced by Langan, November 2018 !.

Discrete Soil Sample Collected for Four-Point Composite Laboratory Analytical Samples (L7-COMP-1, L7-COMP-2, L8-COMP-1, & L8-COMP-2)Approximate Extent of Former Hidden Glenn LandfillLidar Contour - 1ft. IntervalSoil Borings on 15 ft. CentersFormer Hidden Glenn Landfill Buffer - 10 ft.Approximate Location of Soil Sample Exceeding Class I non-RCRA State of California Hazardous Waste Criteriaand Residential ESL for LeadApproximate Location of Soil SampleExceeding Residential ESL for LeadAssessor's Parcel Boundaries •
CJ
-
ICC
LAN6AN

ATTACHMENT 6
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Parcel No. 10
APN: 045411020000
Pascale Place
L10-B-46
L10-B-47
L10-B-44
L10-B-45
L10-B-43
L10-B-41
L10-B-42
L10-B-39
L10-B-40
L10-B-34
L10-B-37
L10-B-38 L10-B-32
L10-B-33
L10-B-35
L10-B-36 L10-B-30
L10-B-31
L10-B-24
L10-B-28
L10-B-29
L10-B-22
L10-B-23
L10-B-26
L10-B-27
L10-B-20
L10-B-21
L10-B-25
L10-B-18
L10-B-19
L10-B-16
L10-B-17
L10-B-11
L10-B-12
L10-B-09
L10-B-10
L10-B-08 L10-B-06
L10-B-04
L10-B-05
L10-B-03
L10-B-01
143
135
13 1
4 3
1 3
3 1
2 31
130
129
125
124
123
122
120
11 1
7 16
115
114
11 1
3 1
11 2
1 11
10 0
1 9
08 107
106
105
144
142
141
140
139
138
137
136
128
127
126
121
136
135
134
133
132
131
130
138
137
136
112
111
119
118
104
143
141
129
129
129
128
115
110
104
Date 4/23/2019 Project 750649501
0 10 20 40
Feet
\\langan.com\data\OAK\data5\750649501\Project Data\ArcGIS\MXD\Environmental_Figures\Discrete Sampling Figures_April 2019\Lot Specific Report Figures\Lot 10 Haz Waste.mxd User: bsaylor FORMER HIDDEN GLEN LANDFILL INVESTIGATION Napa, California LOT 10 - SITE PLAN

WITH APPROXIMATE SOIL SAMPLE LOCATIONS

EXCEEDING RESIDENTIAL ESL FOR LEAD
Figure 2
q Soil Sampling Analytical Results Sample ID Total Lead (mg/kg) STLC (mg/L) TCLP (mg/L) L10-COMP-1 37 -- --
L10-B-05 13 -- -- L10-B-18 37 -- -- L10-B-25 11 -- -- L10-B-27 83 0.82 -- L10-COMP-2 140 3.3 0.027
L10-B-12 79 4.5 -- L10-B-23 47 -- -- L10-B-31 140 1.6 0.022 L10-B-42 61 1.1 -- Residential ESLs - Cancer Risk
1 82 -- --
Residential ESLs - NonCancer Hazard
1 80 -- --
TTLC2 (mg/kg) 1,000 -- --
STLC2 (mg/L) -- 5 -- TCLP2 (mg/L) -- -- 5 Notes: 1. San Francisco Bay Regional Water Quality Control Board (RWQCB), Direct Exposure Human Health Risk Levels (Table S-1), Soil Residential: Shallow Soil Exposure, Cancer Risk and Non-Cancer Hazard Environmental Screening Levels, dated January 2019. 2. Hazardous Waste Criteria 3. Bold concentration exceeds the lower of the Cancer Risk or Non-Cancer Risk ESLs. 4. TTLC - California Total Threshold Limit Concentration - State hazardous waste criterion

5. STLC - California Soluble Threshold Limit Concentration 6. TCLP - Federal Toxicity Characteristic Leaching Procedure 7. World aerial imagery basemap is provided through Langan’s Esri ArcGIS software licensing and ArcGIS online. Credits: Esri, DigitalGlobe, GeoEye, i-cubed, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, and the GIS User Community. 8. All features shown are approximate. 9. Site boundary provided by the Napa County parcel dataset, 2016. 10. LiDAR survey data for the northern San Francisco Bay, CA provided by National Oceanic and Atmospheric Administration (NOAA) with accuracy of 1 meter, updated 2010.

Legend
Approximate Location of Soil BoringAdvanced by Langan, December 2018 !.

Discrete Soil Sample Collected for Four-Point Composite Laboratory Analytical Sample (L10-COMP-1 & L10-COMP-2)Approximate Extent of Former Hidden Glenn LandfillLidar Contour - 1ft. IntervalSoil Borings on 15 ft. CentersFormer Hidden Glenn Landfill Buffer - 10 ft.Approximate Location of Soil SampleExceeding Residential ESL for LeadAssessor's Parcel Boundaries •
CJ
-
c::::J
LAN6AN

ATTACHMENT 6
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!.

City of Napa Parcel
APN: 045411022000
Pascale Place
LA-B-22
LA-B-23
LA-B-20
LA-B-21
LA-B-19
LA-B-17
LA-B-18
LA-B-15
LA-B-16
LA-B-14 LA-B-12 LA-B-13
LA-B-10
LA-B-11
LA-B-09
LA-B-07
LA-B-08
LA-B-05
LA-B-06
LA-B-04
LA-B-03
LA-B-01
LA-B-02
137
136
135
134
133
132
131
130
129
128
127
126
125
124
123
122
121
120
119
118
117
116
115
114
113
112
111
110
109
108
107
106
105
104
103
102
101
10 9
0 9
98 96
95 94
93 92
12 1
7 26
129
128
9 94
5 97
128
91 128
110
105
101
100
129
128
128
104
Date 4/30/2019 Project 750649501
0 10 20 40
Feet
\\langan.com\data\OAK\data5\750649501\Project Data\ArcGIS\MXD\Environmental_Figures\Discrete Sampling Figures_April 2019\Lot Specific Report Figures\Lot A Haz Waste.mxd User: ogodfrey FORMER HIDDEN GLEN LANDFILL INVESTIGATION Napa, California LOT A - SITE PLAN

WITH APPROXIMATE SOIL SAMPLE LOCATIONS

EXCEEDING CLASS I NON-RCRA STATE OF

CALIFORNIA HAZARDOUS WASTE CRITERIA

AND RESIDENTIAL ESL FOR LEAD
Figure 2
q Soil Sampling Analytical Results Sample ID Total Lead (mg/kg) STLC (mg/L) TCLP (mg/L) LA-COMP-1 53 1.5 --
LA-B-08 12 -- -- LA-B-10 50 0.49 -- LA-B-18 150 7.7 0.044 LA-B-19 34 -- -- Residential ESLs - Cancer Risk
1 82 -- --
Residential ESLs - Non-Cancer Hazard
1 80 -- --
TTLC2 (mg/kg) 1,000 -- --
STLC2 (mg/L) -- 5 -- TCLP2 (mg/L) -- -- 5
Notes:1. San Francisco Bay Regional Water Quality Control Board (RWQCB), Direct Exposure Human Health Risk Levels (Table S-1), Soil Residential: Shallow Soil Exposure, Cancer Risk and Non-Cancer Hazard Environmental Screening Levels, dated January 2019. 2. Hazardous Waste Criteria 3. Bold concentration exceeds the lower of the Cancer Risk or Non-Cancer Risk ESLs. 4. Bold Italicized - concentration exceeds hazardous waste criteria. 5. TTLC - California Total Threshold Limit Concentration - State hazardous waste criterion

6. STLC - California Soluble Threshold Limit Concentration 7. TCLP - Federal Toxicity Characteristic Leaching Procedure 8. World aerial imagery basemap is provided through Langan’s Esri ArcGIS software licensing and ArcGIS online. Credits: Esri, DigitalGlobe, GeoEye, i-cubed, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, and the GIS User Community. 9. All features shown are approximate. 10. Site boundary provided by the Napa County parcel dataset, 2016. 11. LiDAR survey data for the northern San Francisco Bay, CA provided by National Oceanic and Atmospheric Administration (NOAA) with accuracy of 1 meter, updated 2010.

Legend
Approximate Location of Soil BoringAdvanced by Langan, December 2018 !.

Discrete Soil Sample Collected for Four-Point Composite Laboratory Analytical Sample (LA-COMP-1)Approximate Extent of Former Hidden Glenn LandfillLidar Contour - 1ft. IntervalSoil Borings on 15 ft. CentersFormer Hidden Glenn Landfill Buffer - 10 ft.Approximate Location of Soil Sample Exceeding Class I non-RCRA State of California Hazardous Waste Criteriaand Residential ESL for LeadAssessor's Parcel Boundaries I
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ATTACHMENT 6
Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024

APPENDIX D
Site Health and Safety Plan

Site Health and Safety Plan
Hidden Glen Dump
Coombsville Road
Napa, California
SWIS No. 28-AA-0028
Napa County Local Enforcement Agency
1195 Third Street, Suite 210 I Napa, California 94559
October 1, 2024 | Project No. 109558001
Geotechnical | Environmental | Construction Inspection & Testing | Forensic Engineering & Expert Witness Geotechnical | Environmental | Construction Inspection & Testing | Forensic Engineering & Expert Witness Geophysics | Engineering Geology | Laboratory Testing | Industrial Hygiene | Occupational Safety | Air Quality | GIS Geophysics | Engineering Geology | Laboratory Testing | Industrial Hygiene | Occupational Safety | Air Quality | GIS Geotechnical & Environmental Sciences Consultants

Stephen J. Waide, CIH, CSP, CIEC, CMC
Principal Environmental Scientist
Site Health and Safety Plan
Hidden Glen Dump
Coombsville Road
Napa, California
SWIS No. 28-AA-0028
Mr. Peter Ex, REHS
Napa County Local Enforcement Agency
1195 Third Street, Suite 210 I Napa, California 94559
October 1, 2024 | Project No. 109558001
5710 Ruffin Road | San Diego, California 92123 | p. 858.576.1000 | www.ninyoandmoore.com NDD/BAB/SW/mp
Geotechnlcal & Environmental Sciences Consultants

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 i

CONTENTS
1 INTRODUCTION 1
2 PROJECT OBJECTIVES AND SCOPE 1
3 SITE LOCATION AND DESCRIPTION 2

3.1 General 2

3.2 Known Contaminants 2
4 KEY PERSONNEL AND RESPONSIBILITIES 2
5 EMPLOYEE TRAINING ASSIGNMENTS 3

5.1 General Training Requirements 3
6 HAZARD IDENTIFICATION AND ANALYSIS 3

6.1 Chemical and Explosive Hazards 4

6.2 Dust 4

6.3 Odors 4

6.4 Landfill Gases 4

6.4.1 Methane Gas 5

6.4.2 Hydrogen Sulfide 5

6.4.3 Vinyl Chloride 5

6.5 Metals 5

6.6 Petroleum Hydrocarbons 6

6.7 Semi-Volatile Organic Compounds 6

6.8 Organochlorine Pesticides 7

6.9 Polychlorinated Biphenyls 7

6.10 Physical Hazards 8

6.10.1 General Physical Hazards 8

6.10.2 Vehicle and Heavy Equipment Operation 8

6.10.3 Slip, Trip and Fall 8

6.10.4 Manual Lifting Techniques 9

6.10.5 Noise 9

6.10.6 Sunburn 9

6.10.7 Heat Stress 9

6.11 Waste Disposal Site Excavation Hazards 10

6.11.1 Buried Objects 11

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 ii

6.11.2 Wastes and Soil Excavation/Trenching 11

6.11.3 Overhead Hazards 11

6.11.4 Fire and Explosion Hazards 12

6.11.5 Oxygen Deficiency 12

6.12 Biological Hazards 12

6.12.1 Rattlesnakes 12

6.12.2 Insects and Arachnids 13

6.12.3 Poisonous Plants 13

6.13 Radiological Hazards 13
7 SPILL PREVENTION AND CONTROL MEASURES 14

7.1 Preventive Measures 14

7.2 Spill Containment Measures 14

7.3 Record Keeping and Notifications 15
8 HAZARD MONITORING 15

8.1 Air Monitoring 15

8.2 Instrumentation 15

8.3 Frequency 15

8.4 Dust Monitoring 15

8.5 Calibration and Documentation 16

8.6 Personnel Monitoring 16

8.7 Fire Extinguishers 17

8.8 Severe Weather 17
9 PERSONAL PROTECTIVE EQUIPMENT 17
10 CONFINED SPACE ENTRY 18
11 DECONTAMINATION 18

11.1 Personnel Decontamination 18

11.2 Vehicle and Equipment Decontamination 18
12 MEDICAL SURVEILLANCE REQUIREMENTS 19
13 SITE CONTROL 19

13.1 Controlled Area Designation 19

13.2 Open Trenches 19

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 iii 14 CONTINGENCY PLAN 20
15 EMERGENCY ACTION PLAN 20
TABLES
1 – Key Personnel and Contact Information 3
2 – Training Assignment Matrix 3
3 – Radiation Types and Action Levels 14
4 – Air Monitoring Action Levels 16
5 – Action Levels for Heat Stress 17
6 – Personal Protective Equipment Levels 18
FIGURE
1 – Hospital and Route Map

APPENDIX
A – Site Health and Safety Plan Acknowledgement Form

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 1 1 INTRODUCTION
This Site Health and Safety Plan (SHSP) provides policies, information, requirements, and guidelines regarding procedures to be followed by field personnel, subcontractors, and others during the implementation of the Remedial Action Plan for the Hidden Glen dump (site). The site is located near the intersection of Pascale Place and Glory Court in Napa, California (Figures 1 and 2 of the RAP).

An effective SHSP is one that is comprehensive enough to provide for contingencies, and also to provide a structure for handling a variety of situations as they arise, but concise enough so that site workers understand the potential hazards and are able to follow the procedures to reduce the level of risk. It should be noted that no SHSP can completely eliminate risk from a work site. Site personnel working within the work area will be trained and current in accordance with the standards provided by Hazardous Waste Operations and Emergency Response (HAZWOPER) (40-hour initial training with annual updates). Appropriate management personnel will also have 8-hour supervisor training. All personnel, including subcontractors, working in or near the Project will have current HAZWOPER certification. The requirement for current HAZWOPER certification of personnel (tradesmen) working onsite but not related to the Project will be at the discretion of the SHSO.

The Ninyo & Moore Certified Industrial Hygienist (CIH) assisted and oversaw preparation of this SHSP. The CIH will discuss the contents of this plan with the Site Health Safety Officers (SHSO) immediately prior to beginning fieldwork, and as necessary, during the course of the Project. The air monitoring/field screening will be conducted to comply with the SHSP.

This SHSP was prepared in general accordance with the Federal Occupational Safety and Health Administration Hazardous Waste Operations and Emergency Response Standard (29 Code of Federal Regulations 1910.120) and California Code of Regulations, Title 8 Section 5192. Work will be performed under the oversight of a California-licensed professional geologist (PG) and/or certified engineering geologist (CEG).
2 PROJECT OBJECTIVES AND SCOPE
Details of the remedial action is included in the Remedial Action Plan (RAP) prepared concurrent with this SHSP. The remedial action for the site generally consists of excavating and removing wastes in the buffer zone (Figure 2 and 3 of the RAP) (e.g., areas between the capped portion of the dump and the adjacent residential properties/lots) and reconsolidating these wastes onsite at the southeast portion of the capped dump. Excavated waste may be reconsolidated onsite or, at the City’s discretion, disposed of at an offsite waste facility.

Reconsolidated waste will be placed on the existing cap and covered with 2 feet of clean

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 2 imported soil. At a minimum, waste will be removed within the buffer zone and extend to the adjacent property boundaries. Under this option, no waste will be removed from the adjacent properties. However, if an adjacent property owner agrees, waste removal will “feather” from the buffer zone across the property line.
3 SITE LOCATION AND DESCRIPTION

3.1 General
The site as it pertains to the RAP is the City-owned Parcel A consisting of the capped portion of the dump and the area between the capped area and the adjacent properties referred to as the “buffer zone” (Figure 2). The dump is located in a residential setting with wastes occurring at the previously capped portion of the dump, “buffer zone” and at adjacent residential properties downslope to the north, west, and south and generally upslope to the east. Adjacent residential properties are not separated by a road or other features. A cemetery is located across Pascale Place to the west.

3.2 Known Contaminants
Based on historical records of the City owned parcel and adjacent properties, wastes generally consists of automobiles, general garbage burned and spread, tree prunings and brush, asphalt and concrete wastes, metal slag, rusted metal, wood fragments, brick and/or pottery fragments, glass including melted glass, gravel debris, and small fragments of charcoal.

Based on historical records elevated lead and total petroleum hydrocarbons (TPH) concentrations were detected at the dump site and on adjacent properties. Other constituents of potential concern (COPCs) include landfill gas, metals, total petroleum hydrocarbons (TPH), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and volatile and semivolatile organic compounds (VOCs and SVOCs, respectively). PCBs, OCPs, VOCs and SVOCs were detected in soil samples at concentrations below their respective Region Water Quality Control Boards Environmental Screening Levels and may be present at the site. 4 KEY PERSONNEL AND RESPONSIBILITIES
This section describes key personnel and their responsibilities. Job titles and applicable contact information is provided in the following Table 1.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 3 Table 1 – Key Personnel and Contact Information
Title Name Office Cell Phone E-mail
City of Napa Engineer
and Project Manager Chris Jones 707.257.9460 310.344.5676 [email protected] Ninyo & Moore
Senior Staff, SHSO
Connor
Escobar 408.435.9000 408.393.4233 [email protected] Ninyo & Moore
Project Manager
Nathan
Diem 858.576.1000 510.584.7217 [email protected]
Ninyo & Moore
Principal Geologist
Beth
AbramsonBeck858.576.1000 760.492.6249 [email protected] Ninyo & Moore
Corporate Health and
Safety Manager
Jason Shipe 858.576.1000 714.852.2160 [email protected] 5 EMPLOYEE TRAINING ASSIGNMENTS

5.1 General Training Requirements
A matrix summarizing training requirements for Ninyo & Moore personnel, excavation subcontractor personnel, visitors, and vendors is presented in the following table:

Table 2 – Training Assignment Matrix
Category
40-Hour

HAZWOPER
8-Hour
Refresher
24 Hours
Supervised
Experience
8-Hour
Supervisor
Excavation
Competent
Person
Ninyo & Moore SHSO X X X X X
RABC-ECC Construction
Supervisor X
Subcontractor Supervisor X X X X X
Subcontractor Staff X X X
Visitor X1 X1 X1
Vendor X1 X1 X1
Note:
1 = Not required if escorted
6 HAZARD IDENTIFICATION AND ANALYSIS
The potential hazards to personnel working at the site include, but are not limited to the following:
• Chemical exposure associated with unknown types of wastes. • Explosive hazards related to landfill gases/elevated methane concentrations. This plan specifies safe working practices including monitoring and avoiding and/or dealing with management of potential explosive gas conditions.
• Physical hazards related to the site use of the property that uses heavy equipment (trucks and other machinery; presence of partially obscured uneven terrain and stockpiled soils and debris; noise; and excavation hazards including cave-ins and atmospheric hazards, and encountering unknown and/or unidentifiable buried objects and potentially hazardous materials associated with the wastes and heat stress and sunburn.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 4 • Biological hazards (ticks, bees, wasps, snakes, spiders).

Each potential hazard is described below.

6.1 Chemical and Explosive Hazards
Health hazards associated with potential chemical exposures at this site include toxic and potentially explosive environments. The most likely route for exposure to toxic chemicals is through inhalation of chemical vapors or contaminated dust that could potentially be released from the subsurface during excavation or trenching. Secondary routes for chemical exposure include dermal absorption, injection, and ingestion. Exposure to explosive levels of contaminants, particularly landfill gases may be encountered during Project site activities. The overall risk to field personnel from these potential exposures will be controlled through the use of careful airborne monitoring, PPE and safe work practices as described in this plan under Hazard Monitoring, PPE and Site Control, respectively.

Based on background information, expected COPCs are discussed in Section 3.2. Conservative action levels for these contaminants have been identified in this plan. Refer to Section 9, Hazard Monitoring, for appropriate action levels regarding the potentially hazardous materials/COPCs.

6.2 Dust
Material removal, stockpiling of bulk soil and other materials, handling of potentially contaminated soil or other items, and general excavation and grading can generate airborne dust that can become a nuisance or a hazard to nearby sensitive receptors. In addition, certain contaminants can adhere or adsorb to various particles in dust, resulting in potential offsite impacts. Visible dust will be monitored and controlled at the site by the Contractor. The Project Environmental Consultant will monitor dust at the site perimeter during soil disturbance activities, if indications of possible contamination are encountered.

6.3 Odors
If landfill wastes are encountered, odors may be present as a result of degradation of buried organic wastes in the landfill. Odor monitoring by qualitative (olfactory) and semi-quantitative (photoionization detector [PID]) methods and by LFG monitoring will be performed to identify potential odor issues.

6.4 Landfill Gases
Because of the possibility of decomposition of organic materials buried at the site (e.g., municipal solid waste), a discussion of landfill gases is necessary. Decomposition of organic

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 5 material results in the production of several gases that may present a safety and health concern.

6.4.1 Methane Gas
Methane gas has been monitored at the site since December 2020 and is currently monitored on a quarterly basis. Methane monitoring results have been below regulatory limits during all monitoring events. Methane gas may be encountered during excavation activities. Methane is odorless and non-toxic, but can present an explosive hazard in high concentrations, can act as a simple asphyxiant (can displace oxygen) in low-lying areas or confined spaces, and may be an indicator of the presence of other potentially hazardous landfill gases. Methane will continue to be monitored as an explosive gas.

6.4.2 Hydrogen Sulfide
Hydrogen sulfide (H2S) is a colorless, heavier-than-air gas with a characteristic odor. (Note that desensitization can occur, i.e., the inability to “smell” the odor, resulting in increased danger of overexposure.) H2S is commonly found at landfills as a result of waste decomposition. It can be toxic or fatal if inhaled in high concentrations.

6.4.3 Vinyl Chloride
Vinyl chloride results from the decomposition of chlorinated materials such as plastics and solvents. Vinyl chloride is a recognized human carcinogen. The Occupational Safety and Health Administration (OSHA) standard for vinyl chloride (to occupational workers) established an exposure limit of 1 ppm as a time-weighted average (TWA) and 5 ppm as a short-term exposure limit (i.e., 15 minutes). The action levels established for this site are designed to adequately protect the public from fugitive emission of this toxic gas. In the unlikely event that site conditions indicate the need to monitor worker exposures to vinyl chloride, perimeter monitoring will be initiated. The CHSM will determine the type and frequency of monitoring based on site conditions.

6.5 Metals
Elevated concentrations of lead at the site have been documented during previous site assessments activities. Although metal and metal ions do not present volatility or flammability problems, they can present acute and chronic effects if the host material is inhaled in the form of dust or fumes. Metal ions can cause irritation of mucous membranes and lung tissues and some metals such as lead are suspected carcinogens. Public exposure to metals in the burned waste

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 6 and soil by dermal contact or ingestion is not likely. Therefore, this plan addresses potential exposure by inhalation of dust containing metals generated by site activities.

Lead is the primary metal of concern. It is a toxic heavy metal and a suspected carcinogen that may be encountered in inorganic or organic forms. The Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL)- time weighted average (TWA) for lead in air is 0.05 milligram per cubic meter (mg/m3). Visible dust will be monitored and controlled during construction activities as described in Section 7.

6.6 Petroleum Hydrocarbons
TPHmo and TPHd were detected in soil samples in adjacent properties (Langan, 2019). TPH is a term used to describe a large family of several hundred chemical compounds that originally come from crude oil. TPH is a mixture of chemicals, but they are all made mainly from hydrocarbons.

Some chemicals that may be found in TPH are hexane, jet fuels, mineral oils, benzene, toluene, xylenes, naphthalene, and fluorene, as well as other petroleum products and gasoline components.

Some of the TPH compounds can affect your central nervous system. One compound can cause headaches and dizziness at high levels in the air. Another compound can cause a nerve disorder called "peripheral neuropathy," consisting of numbness in the feet and legs. Other TPH compounds can cause effects on the blood, immune system, lungs, skin, and eyes.

Animal studies have shown effects on the lungs, central nervous system, liver, and kidney from exposure to TPH compounds. Some TPH compounds have also been shown to affect reproduction and the developing fetus in animals. The International Agency for Research on Cancer (IARC) has determined that one TPH compound (benzene) is carcinogenic to humans.

IARC has determined that other TPH compounds (benzo[a]pyrene and gasoline) are probably and possibly carcinogenic to humans. Most of the other TPH compounds are considered not to be classifiable by IARC.

6.7 Semi-Volatile Organic Compounds
Semi-volatile organic compounds (SVOC) have been detected in soil samples below regulatory screening levels from adjacent properties and include bis (2-ethylhexyl), phthalate, and pyrene (Langan, 2019). Although SVOCs have not been detected at elevated concentrations, SVOCs may be encountered during excavation actives and for the purpose of this CHSP, hazards are explained below.

SVOCs area organic compound which have a boiling point higher than water and which may vaporize when exposed to conditions above room temperature. Significant airborne levels of

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 7 SVOCs are not typical during fieldwork however they can be present in airborne dust. SVOCs include phenols and PAHs. Short-term effects of phenol exposure include respiratory irritation, headaches, and burning eyes. Chronic effects of high exposures include weakness, muscle pain, anorexia, weight loss, and fatigue; effects of long-term low-level exposures include increases in respiratory cancer, heart disease, and effects on the immune system. PAHs are produced from coal tar and other sources and are used in a variety of industrial products. PAH is a recognized human carcinogen. Studies in animals have also shown that PAHs can cause harmful effects on skin, body fluids, and the body's system for fighting disease after both shortand long-term exposure; however, these effects have not been reported in people. The current OSHA PEL is 0.2 milligrams per cubic meter (mg/m3); however, exposure by any route to PAH and other recognized human carcinogens will be maintained at the absolute practicable minimum level. Exposure to SVOCs are expected to be adequately controlled with the designated action levels for airborne vapor and dust.

6.8 Organochlorine Pesticides
OCPs were detected in soil samples below regulatory screening levels in adjacent properties and include endosulfan, p,p-DDD, p,p-DDE, and p,p-DDT, aldrin, alpha- BHC, and dieldrin (Langan, 2019). As with PAHs above, action levels for lead and total dust will serve to keep exposure to OCPs well below recognized exposure limits and should eliminate offsite impacts.

6.9 Polychlorinated Biphenyls
PCBs have been detected in soil samples below regulatory screening levels. Although PCBs are not expected at elevated concentrations, for the purposes of this CHSP, hazards are described below.

PCBs, also referred to as aroclors, are synthetic industrial products which have been commonly used as cooling fluid and for electrical insulation. PCBs are common contaminants of oily type waste and are found around railroad tracks and in industrial areas and dumps. PCBs are recognized environmental pollutants and suspected human carcinogens.

The United States Environmental Protection Agency (EPA) currently classifies PCBs as a Class B2, or probable, human carcinogen. Skin exposure may contribute significantly to uptake of these chemicals, and therefore all skin exposure should be strictly avoided. Work involving exposure to PCBs above the atmospheric action level or in contact materials exceeding 100 micrograms per gram may require special medical evaluation and approval of the SHSO.

PCBs are not volatile and exposure will be controlled by limiting airborne dust.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 8

6.10 Physical Hazards
Accidents involving physical hazards can directly injure field personnel and can create additional hazards such as increased exposure to chemicals due to damaged protective equipment. One of the most common potential hazards is improper bending and lifting which may result in back injuries. Field personnel should implement proper lifting techniques when handling equipment and material. Field personnel should maintain awareness of potential safety hazards at each specific activity location and should immediately inform other field personnel of any new hazards so that corrective measures can be taken.

6.10.1 General Physical Hazards
The site is currently an undeveloped open space. Portions of the property currently include uneven terrain and steep slopes around the perimeter. A careful pre-work walkover should be made of each work area and potential access or egress routes. Unsafe areas may be flagged or taped and will be identified to all field personnel.

6.10.2 Vehicle and Heavy Equipment Operation
Vehicles should only be operated in authorized areas. When moving equipment, caution should be exercised in order not to damage equipment or cause injury. When backing up heavy vehicles (larger than pickup trucks), passenger vehicles, or pickups with obscured rear vision, a guide should be used to direct the vehicle. Extra caution should be exercised during vehicle operation on dike roads, industrial areas, and other close spaces. Personnel directing traffic should wear orange vests. Each vehicle should be equipped with a minimum of one fire extinguisher rated 3A:40B:40C.

6.10.3 Slip, Trip and Fall
Possible slip, trip and fall hazards can occur at the site due to the uneven and potential obscured terrain during construction activities. The SHSO will remind field personnel at the daily tailgate meetings to maintain sure footing on all surfaces. In addition, although unlikely at this time of year, wet weather conditions may also pose such hazards when working outdoors. The work locations will be kept as tidy as possible and in order to minimize tripping hazards caused by job supplies and equipment, tools and materials should not be left randomly on surfaces when not in direct use. Foot traffic should avoid areas where materials are stored on the ground. Any hoses and cables should be grouped, routed to minimize hazards, and covered with a ramp or bridge or clearly marked with hazard tape or flags if such material will remain in place for more than one day. Personnel should wear appropriate footwear for site conditions and walk carefully.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 9

6.10.4 Manual Lifting Techniques
During any manual material-handling tasks, personnel will be trained to lift with the force of the load suspended on their legs and not on their backs. An adequate number of personnel or an appropriate mechanical device must be used to safely lift or handle heavy equipment. When heavy objects must be lifted manually, workers should keep the load close to the body and avoid any twisting or turning motions to minimize stress on the lower back. A lifting orientation and specific back stretching and warm-up exercises will help minimize the potential for back injuries.

Use of these exercises by all field personnel at the start of each shift should be encouraged.

6.10.5 Noise
Noise is a potential hazard in areas where heavy equipment is operated such as during the Project activities. Intermittent high noise levels are expected at the site associated with the use of mechanical excavation equipment. Ambient noise levels as well as equipment operation will likely result in noises that reach or exceed 85 decibels, the action level established by the OSHA. Exposure to elevated noise levels can lead to temporary or permanent hearing loss and can also cause muscle tension and irritability. The SHSO will ensure hearing protection is utilized when noise levels are elevated. Elevated noise levels will be evaluated by the SHSO when equipment is operated. Excess noise levels can be estimated using the following rule of thumb. When normal voice communication is not possible between field personnel who are no more than 3 feet apart, hearing protection will be utilized. Hearing protection typically involves the use of disposable ear plugs for the duration of the excessive noise condition and will be used during operations that present a noise hazard.

6.10.6 Sunburn
Working outdoors on sunny days for extended periods of time can cause sunburn. Excessive exposure to sunlight is associated with the development of skin cancer. Field staff should take precautions to prevent sunburn by using sun-screen lotion and/or wearing hats and longsleeved garments.

6.10.7 Heat Stress
Heat stress is an important health consideration on worksites. High temperatures, in conjunction with wearing personal protective clothing, may aggravate heat-stress problems.

Standard measures, including designating a shaded rest area, taking frequent rest breaks, and performing heat-stress monitoring of workers, will be used to minimize heat-stress-related problems. A readily available supply of liquids, such as water and fluids containing electrolytes, will be available at the work site to replenish body fluids. Visual observation of workers by the

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 10 SHSO for heat-stress-related signs and symptoms, and body core temperature monitoring will be performed when outside temperatures exceed 70 degrees Fahrenheit (°F) and impermeable clothing is being worn, when outside temperatures exceed 90°F in street clothes, or whenever other conditions warrant. Signs and symptoms of heat stress include profuse sweating, headache, skin flushing, dizziness, confusion, and rapid heart rate. Workers exhibiting a body core temperature of 100.4°F or greater (measured at the ear drum) will be removed to a cooler area or activity until body core temperature returns to below 99°F.

If persons exhibiting heat-stress symptoms are left untreated, the condition can elevate to heat stroke. Heat stroke is typically manifested by hot, dry skin with a body core temperature of 104°F or greater. Heat stroke can be fatal if treatment is delayed. Therefore, persons exhibiting heat-stroke symptoms need to have their core temperature reduced immediately by use of cold packs, cold water wipes, or immersion. Heat-stroke victims need to be transported to a professional medical facility immediately after the victim’s core temperature has been reduced or while the victim’s core temperature is being reduced.

6.11 Waste Disposal Site Excavation Hazards
Project activities at waste disposal sites may expose personnel to various health and safety hazards. The following sections present a summary of the common hazards expected and general methods that will be utilized by the SHSO to help assure worker safety. The SHSO or designee will observe all operations to oversee safety hazards.

Before the start of excavation activities, a "competent person" in accordance with 29 CFR 1926.650 (a person who has the knowledge and training to identify hazards and the authority to correct the hazards) will ensure that the following activities are completed:
• Remove or secure any surface obstacles, such as trees, rocks and sidewalks, that may create a hazard.
• Classify the type of soil and rock deposits at the site. One visual and at least one analytical classification should be made.

The following safety rules must be implemented during excavation activities when personnel are to enter the excavation:
• In excavations greater than four feet, and where hazardous atmospheres exist, or could reasonably be expected to exist, the competent person will test the air before entering the excavation. The competent person will use a photo-ionization detector (PID) to test for VOCs and a combustible gas indicator (CGI) to test for the presence of oxygen, carbon monoxide, hydrogen sulfide, and explosive concentrations of gases or vapors.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 11 • Keep materials or equipment that might fall or roll into an excavation at least two feet from the edge.
• Adequate protection from falling rock, soil or other materials and equipment will be provided in the form of benching, sloping or shoring.
• Do not work in excavations where water has accumulated, or is accumulating, unless adequate precautions have been taken.
• Do not cross over an excavation unless walkways are provided. Guardrails must be provided if the walkway is six feet or more above the bottom of the excavation.

6.11.1 Buried Objects
Buried and partially buried objects such as metal objects, metal cans, lead pipes, glass bottles, broken and melted glass, concrete, asphalt, and brick debris may occur buried, partially buried, and/or near the surface at portions of the site. Workers must take care to prevent injury from handling previously buried objects, including, when necessary, the use of leather outer gloves.

Although not likely, buried underground cables may be present on portions of this site, therefore, an underground utility check should be performed before subsurface construction activities. These pipelines present a source of a potential fire and explosion hazard. All work areas should be cleared prior to trenching and drilling by notifying Underground Service Alert (USA), performing private geophysical clearance (if required), and potholing or other means, as appropriate. In addition, when locations of buried lines are uncertain, excavation should always be performed by hand until the utility is located or the area is cleared.

6.11.2 Wastes and Soil Excavation/Trenching
Excavation of wastes and potentially contaminated soil presents multiple hazards to workers including chemical exposure, fire and explosion hazards, confined space, and exposure to hazards of contacting unidentified energized utilities. A Competent Person will be on site during all excavation activities that will identify the numerous safety issues associated with trenching/excavation. Section 10, Confined Space Entry, provides additional information.

6.11.3 Overhead Hazards
Overhead cables are not expected at the site. If overhead cables are encountered near excavation areas, a hazard analysis should be reviewed prior to operating heavy equipment (excavators) underneath or within 10 feet of the maximum reach of the equipment. All field vehicles and equipment should be maintained at a minimum distance of 10 feet, vertically and

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 12 horizontally, from all electrical power lines (energized lines) and/or electrical equipment with a voltage less than or equal to 50 kilovolts (kv). If the voltage exceeds 50 kv, the clearance will be increased by 4 inches for every 10 kv over that voltage. The location and marking of such lines and equipment will be coordinated with USA prior to the start of construction/excavation activities.

6.11.4 Fire and Explosion Hazards
Care will be taken to assure that explosive mixture monitoring is performed where appropriate, in an adequate manner and that ignition sources are controlled or eliminated.

Combustible gas indicators (CGIs) (aka 5-gasMiniRae) measure explosive mixtures of all landfill gases and will be used for health and safety monitoring onsite without regard to other instruments, which might be used for added information such as the specific components of the gases. The action levels in this plan are based on total LEL measurement and are found in Section 8, Table 4.

6.11.5 Oxygen Deficiency
Oxygen deficiency can occur in confined spaces, open trenches/test pits, or low-lying areas as a result of displacement by another gas (landfill gases, chemical decomposition, or leaking gas cylinders) or by the consumption of oxygen by chemical reaction (rust). Excavations/trenches will not be entered by field personnel once the excavation depth exceeds 3 feet bgs. The SHSO will monitor trenches/test pits and any suspected low-lying areas prior to initial entry.

6.12 Biological Hazards
The SHSO will inform field personnel of the biological hazards at the site. Multiple biological hazards may be present at the site. The most common hazards anticipated are discussed below.

6.12.1 Rattlesnakes
Personnel should be extremely careful when walking through tall grass, rocks, or debris. If a rattlesnake is encountered, slowly and quietly back away from the snake. Inform all personnel at the site of its location. Do not attempt to move or kill a snake because certain species of rattlesnake are protected under state and federal laws. In the event of a snake bite, immediately summon emergency medical services and notify the SHSO. Do not try to move the affected limb; instead, immobilize the injured area, keeping it lower than the heart if possible, and wait for transportation. Do not apply ice, do not cut the wound, and do not apply a tourniquet. The venom should be wiped off the skin since venom will attack intact skin. If you

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 13 know the victim cannot receive medical care within 30 minutes, consider suctioning the wound using a snakebite kit.

6.12.2 Insects and Arachnids
Bees, wasps, yellow jackets, black widow spiders, scorpions, and brown recluse spiders present a potential hazard on this project, especially so for those individuals sensitized to those bites or stings. Prior to initial assignment on this project, personnel with known allergic responses to insect stings will be identified and field supervisors made aware of this condition.

These personnel will also carry an antidote kit if so advised by their physician. The SHSO will confirm that the antidote kit is accessible and notify the emergency medical service providers in the event of any incident.

In all cases, a victim suspected of being bitten by either a black widow or brown recluse spider, or stung by a scorpion will receive medical attention. The venom from the brown recluse spider is capable of causing coma and kidney failure in its victim.

Protection methods against insects may be employed, such as the use of protective clothing or insect repellents, as well as extermination measures, and training in recognition and identification of harmful insects.

6.12.3 Poisonous Plants
Poisonous plants likely are not, but may be present at the site. Poison ivy, poison oak, and poison sumac are identified by three leaves or five leaves emanating from a stem. The plants contain a resin that causes a delayed allergic hypersensitivity reaction on contact. The resin is active in live, dead, dry, and burned plant parts; and it may be carried through the air. Signs and symptoms are usually evident within 24 to 48 hours after exposure. These include burning, stinging, and blisters. Skin reactions associated with the exposure of poisonous plants can be reduced by the application of pre-contact and cleanser treatments applied to the skin prior to and during fieldwork, respectively. If exposure or contact occurs, wash the affected area, but do not spread the resin to uncontacted areas.

6.13 Radiological Hazards
Radioactive hazards are not expected at the site but waste disposal sites of this era contain unclassified wastes and therefore may include radioactive materials. The decision to monitor for radioactive materials will be at the discretion of the SHSO. If determined necessary by the SHSO(s), a general-use alpha-beta-gamma detection instrument will be used to screen materials. The following table provides radiation types and their properties.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 14 Table 3 – Radiation Types and Action Levels
Type Measurement Action Level Action
External alpha/beta/gamma > 2 X Background Contact CIH
Transferable alpha/beta/gamma contamination > 2 x background Contact CIH Notes:
mR = milliroentgen
CSHM = Corporate Health and Safety Manager
The action level for contacting the project Certified Industrial Hygienist (CIH) is set at two times (2x) background radiation.
7 SPILL PREVENTION AND CONTROL MEASURES
Liquids and other potentially spilled materials are not anticipated to be used during this fieldwork. In case unanticipated conditions are encountered and these types of materials are subsequently brought into the field, the following applies:

7.1 Preventive Measures
• Inspect all containers upon delivery to the site for visible defects and ensure that each drum or container includes a re-sealable lid.
• Set any 55-gallon drums on wooden pallets where possible. • Perform weekly inspections of the storage area.
• Select flat areas for temporary storage away from high-traffic zones and storm or sewer drains.

7.2 Spill Containment Measures
The following actions will be taken by RABC-ECC or their subcontractor field personnel assigned to the field activities in the event of a spill:
• The Project Manager and SHSO(s) are to be notified immediately; • Workers not involved in spill containment and/or cleanup shall evacuate the immediate area and designated emergency response personnel attired in appropriate PPE (see Section 9), shall proceed to the spill area with a spill cleanup and control kit, including absorbent materials; • Attempts shall be made to stop the source(s) of spillage immediately; and • The SHSO shall monitor for exposure to chemicals or hazardous substances during spill cleanup work and shall stay at the spill area until the area has been cleared, inspected, and readied for reentry. A spill incident report shall be prepared by the SHSO.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 15

7.3 Record Keeping and Notifications
The SHSO shall thoroughly document the spill in an Incident Report which will be forwarded to the Corporate Health and Safety Manager and Project Manager(s). Records of all hazardous materials releases shall be maintained with the project files. The Project Manager(s) will make any necessary notifications to off-site authorities and the SHSO will approve the reentry to the site for routine use and will issue a final release report pertaining to cleanup of the area. 8 HAZARD MONITORING
During fieldwork, excavating/trenching will be performed in only one area at a time using a CAT excavator (or equivalent). Air monitoring will be performed during excavating/trenching, at the point of contact with wastes and soil being excavated and near the worker’s breathing zones. The person to be monitored will likely be personnel in the closest proximity to open trenches. The methods, frequencies, and action levels for chemical agent monitoring are specified in Table 4.

8.1 Air Monitoring
Air monitoring for the purposes of worker protection will occur during all intrusive activity (waste excavation). While entry into excavations/trenches is not anticipated appropriate instrumentation, a 5- gas MiniRae [or equivalent] will be used on site to allow the SHSO to obtain the best available information on potential atmospheric hazards.

8.2 Instrumentation
The monitoring instrument to be used during site activities is a 5-gas MiniRae meter (or equivalent).

The 5-gas meter will be used to measure landfill gases, lower explosive limit (LEL), oxygen levels (as applicable), and VOCs.

8.3 Frequency
Air monitoring for background levels of air contamination upwind of each work location will be performed prior to the start of field activities. Air monitoring with above described instruments will be conducted at a minimum of every 30 to 60 minutes or at the direction of the SHSO. When excavating in waste or if Level “C” conditions are encountered, air monitoring will be performed continuously.

8.4 Dust Monitoring
Dust production will be monitored visually. Airborne exposure to metals, PAHs, PCBs, and dioxins generally occurs through inhaling dust. Vapor monitoring devices do not detect airborne particles and are not a reliable protective method. Therefore, whenever visible airborne dust is produced during site activities, dust suppression techniques such as lightly misting or wetting the area or modifying work

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 16 processes will be required. Although not anticipated, wearing Level “C” PPE (using a respirator with HEPA/OV cartridges) will be required if significant dust cannot be mitigated. The SHSO will direct site personnel to upgrade PPE, as appropriate.

8.5 Calibration and Documentation
Air monitoring equipment will be maintained and calibrated daily to manufacturer specifications before starting work.

8.6 Personnel Monitoring
Personnel monitoring will be initiated if the action levels are exceeded, and/or personnel are required to work using respiratory protection for periods exceeding one hour.

Table 4 – Air Monitoring Action Levels
Chemical/
Hazard Instrument InitialFrequency Action Level Protection Action Volatile
Organic
Compounds
(Organic
Vapor)
PID
Start of task,
hourly,
continuous if
Background to
2 ppm above
background
No action required.
> 2 ppm
Air purifying respirator, half or full face, level
C protection with appropriate
cartridges
> 5 ppm
Air purifying respirator, full face, Level C
protection, personnel monitoring required to
I.D. contaminants
> 10 ppm Supplied air protection, Level B
> 50 ppm STOP WORK.

Landfill/
Combustible
Gas
RKI Eagle (or
equivalent)
Start of task,
hourly,
continuous if
zone of
contamination
encountered
< 10% LEL6 No action.
10% to 20% LEL
Start continuous monitoring; permit only
classified electrical equipment and
nonsparking tools
> 20% LEL STOP WORK, ascertain source of gas
Oxygen
Concentration

RKI EAGLE
(OR

EQUIVALEN
T)
Start of task,
hourly,
continuous if
zone of
contamination
encountered
< 19.5% O2
Leave area, evaluate reason for deficiency,
monitor again remotely or with immediately
dangerous to life or health (IDLH) entry
program

19.5 to 20.5% O2 Slight deficiency, continue continuous monitoring

20.5 to 21.0% O2 Normal range
> 22.0% O2
Elevated reading, check calibration,
investigate cause, STOP any potential sparkproducing activity No action Hydrogen
Sulfide

RKI EAGLE
(OR

EQUIVALEN
T)
Start of task,
hourly,
continuous if
zone of
contamination
encountered
> 10 ppm H2S
Leave area, evaluate reason for elevated
reading, monitor again remotely or with IDLH
entry program
Dust Aerosol
Monitor
Start of task,
hourly > 1 mg/m3 Stop work, institute engineering controls until no visible dust is present Metals/
Others
Visual Dust
Monitoring Continuous Visible Dust
Upgrade to Level C with organic vapor/highefficiency particulate air (HEPA) cartridges.

Slow work & use dust control (water); stop
work if dust is excessive

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 17 Table 5 – Action Levels for Heat Stress
Type Measurement Action Level Action
Ear insertable core temperature 100.4°F or greater Remove from work Ear insertable core temperature <99°F Return to work

8.7 Fire Extinguishers
At least one, fully-charged fire extinguisher should be present on the site in a visible and accessible location, and the location indicated during the tailgate meetings. The minimum acceptable extinguisher rating is 10-pound ABC. The fire extinguisher should be maintained in a fully-charged condition at all times. Extinguishers are to be periodically inspected and maintained in accordance with manufacturer’s specifications.

8.8 Severe Weather
Most construction activities routinely continue through hot weather, cold weather, and light rain. It is recommended that work stop when rain interferes with construction operations to the point of causing a safety hazard. Such hazards can exist when vision is impaired, when workers are more concerned with staying dry than with the work being done, when footing becomes slippery and difficult, or when equipment stability is compromised. When visible lightening occurs, all operations will stop until conditions clear.
9 PERSONAL PROTECTIVE EQUIPMENT
Based on information obtained from historical documents and site visits, the anticipated level of PPE for most of the field activities will be Level D/modified Level D, and if required, Level C. The minimum required level of personal protection during field activities is Level D. In addition, modified Level D will include the use of chemical-resistant gloves mandatory for field personnel during handling of burned wastes and soils. Ear plugs will be worn if, at any time, verbal communication becomes difficult to comprehend within a radius of 3 feet. All PPE must meet current American National Standards Institute standards.

Level C PPE will be required at any activity location where the levels of contaminants exceed the action levels listed in this plan. Upgrading to Level C PPE involves Level D PPE with the addition of Tyvek coveralls, nitrile gloves, and an appropriate respirator with high efficiency particulate air/organic vapor cartridges (HEPA/OV). The following table describes the PPE associated with each level of protection.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 18 Table 6 – Personal Protective Equipment Levels
Level Body Respirator Skin Other
D
Normal work
clothes
Long pants
None Nitrile or Work gloves Hard hat
Safety glasses
Mod. Da Tyvek suit None
Chemical-resistant latex or
nitrile gloves
Hard hat
Safety glasses
C Tyvek suit Air purifying respirator with
HEPA and OV
Chemical-resistant latex or
nitrile gloves
Hard hat
Safety glasses
B Tyvek suit
Self-contained breathing
apparatus or supplied-air
respirator
Chemical-resistant latex or
nitrile gloves
Hard hat
Safety glasses
A
Encapsulating
chemicalprotective suit
Self-contained breathing
apparatus or supplied-air
respirator
Chemical-resistant latex or
nitrile gloves
Hard hat
Safety glasses
Note: a = Where the potential for heat stress exists, modified Level D may be downgraded to Level D if continuous monitoring verifies the absence of organic vapor.

Changes to these specified items of PPE will not be made without the approval of the SHSO.

The SHSO will have the authority to either upgrade or downgrade the level of PPE based on actual site conditions. If at any time there is a potential for increased chemical exposure, the appropriate upgrade of PPE will be required.
10 CONFINED SPACE ENTRY
Site work involves the excavation of large areas, which includes the operation of fuel-fired heavy equipment and possibly, workers performing tasks within the excavation. Ninyo & Moore and subcontractor workers will perform work under the direction of a Competent Person for excavations who will identify and control potential hazards including oxygen deficiency, toxic agent exposure, heat stress, and engulfment. Inspections will occur at least daily, prior to workers entering the excavation.
11 DECONTAMINATION
This section describes personnel, vehicle and equipment decontamination.

11.1 Personnel Decontamination
A minimal decontamination procedure (consisting of washing exposed skin with soap and water) shall be required at the site at the end of each workday and prior to eating, drinking or smoking.

11.2 Vehicle and Equipment Decontamination
The primary focus of any decontamination program is to minimize the spread of contaminated material beyond a given site. During field activities, vehicles and excavation equipment will be

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 19 used at the site. The level of potential contamination for vehicles and equipment at this site is low for support vehicles used in uncontaminated areas and/or for non-intrusive field activities, and medium for intrusive activities at potentially contaminated/contaminated locations. 12 MEDICAL SURVEILLANCE REQUIREMENTS
Site personnel, including subcontractors, directly involved with the field work must meet the medical surveillance requirements of 29 CFR 1910.120 and 8 CCR 5192. All site personnel will be required to participate in their employer’s medical surveillance program before being permitted to work on location. Contractors and subcontractors will be required to demonstrate, by document submittal, their maintenance of OSHA-compliant programs and to maintain records as required by the applicable contract.

Medical surveillance includes baseline medical examinations for field work certification and annual follow-up examinations. Special medical tests or examinations are not anticipated for personnel assigned to this project. The medical surveillance program is conducted under the guidance of an occupational medicine physician who established the medical exam protocol and certification requirements. Medical records of a confidential nature will be maintained by the medical provider or by each employer.
13 SITE CONTROL
Although potential chemical and physical hazards have been identified in this SHSP, if unexpected conditions arise, the SHSO will stop work at the site and notify the appropriate point of contact. Work will not resume until the SHSP and working conditions have been reevaluated and the SHSP revised accordingly.

13.1 Controlled Area Designation
At locations where field activities are taking place such as trenching and sampling, only authorized personnel with the proper training and PPE will be allowed to enter these active work areas which will include the operation of heavy equipment, and the potential for exposure to hazardous conditions/materials. In these areas, access may be controlled with caution tape and/or barricades.

13.2 Open Trenches
Trenches will be immediately backfilled after documenting subsurface conditions and sampling and will not be left open overnight.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 20 14 CONTINGENCY PLAN
In the event of an onsite emergency related to Project activities, the SHSO should notify the project CIH and dial “911,” as appropriate. In case of a medical emergency:
• Remove the exposed or injured person(s) from immediate danger. • Render first aid if necessary. Decontaminate affected personnel if necessary or obtain paramedic service or ambulance transport to the local hospital by calling 911. Another field personnel member will accompany any person to the medical facility and remain with the person until release or admittance is determined.
• If applicable, evacuate other personnel at the facility to a safe distance until the Fire Department determines that it is safe for work to resume. • Any accident/incident resulting in an OSHA-reportable injury or illness, treatment at a hospital or physician’s office, property damage, or a near-accident, requires that an accident/incident report be completed and submitted to the appropriate authorities.

The implementation of a spill contingency plan is not anticipated for this project. The planned field activities involve neither large quantities of materials nor the movement of containers of hazardous materials. For spills of less than one-half gallon, the subcontractor will respond by using rags or sorbent material and dispose of the sorbent material in a labeled container. When reporting a spill, the subcontractor will provide the following information:
• Worker name, organization, phone number, and location. • Number of injured personnel, if any, and nature of injuries if known. • Substance spilled.
• Source and cause of the spill.
• Approximate amount and extent of the spill.
• Approximate rate of release.
• Action taken so far.
• Approximate time spill occurred.
• Any other pertinent information asked by the operator. 15 EMERGENCY ACTION PLAN
In the event of a medical emergency or fire during activities at the project site, the standard “911” emergency telephone number shall be called from an on-site mobile phone. Field personnel have mobile telephones that they can use during site activities. Although unlikely,

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 21 during the daily tailgate meeting if field personnel indicate that they do not have a personal telephone, they will make it known and a telephone will be provided to them or they will work with someone that has an available telephone. A first aid kit and fire extinguisher will be located on site in a readily accessible location. The emergency facility for this project is Providence Queen of the Valley Medical Center. The hospital address is 1000 Trancas St 1st Floor, Napa, CA 94558.

Emergency Number Contact
Medical, Fire or Police 911 Emergency operator
Providence Queen of the Valley Medical
Center
1000 Trancas St 1st Floor, Napa, CA
94558
(707)252-4411 Emergency room
The route from the project site to the hospital is shown on Figure 1.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 22

CERTIFIED INDUSTRIAL HYGIENIST REVIEW
The above Site Specific Health & Safety Plan has been reviewed and approved by the certified industrial hygienist (CIH) indicated below.

Stephen J. Waide, CIH, CSP
Certified Industrial Hygienist No. CP 7005
Expires 6/1/22

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 Appendix A
Photographic FIGURE Documentation

Imagery ©2024 Airbus, Landsat / Copernicus, Maxar Technologies, Map data ©2024 Google 2000 ft Coombsville Rd & Pascale Place
Napa, CA 94559

1. Head northwest on Coombsville Rd toward Little St

2. Slight right onto CA-121 N/Silverado Trail

0.5 mi

2.0 mi
Coombsville Rd & Pascale Place, Napa, CA 94559 to Emergency Room at Providence Queen of the Drive 3.8 miles, 10 min Valley Medical Center, 1000 Trancas St 1st Floor, Napa, CA 94558 Go gle Maps t
1'

3. Turn left onto Monticello Rd

4. Continue onto Trancas St

5. Turn right

6. Turn right
Destination will be on the left
Emergency Room at Providence Queen of the Valley Medical Center
1000 Trancas St 1st Floor, Napa, CA 94558

0.1 mi

1.2 mi
259 ft
85 ft
t
r+
r+
•

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024

APPENDIX A
Site Health and Safety Plan Acknowledgement Form

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024

ONSITE WORKING PERSONNEL SIGN IN
The personnel listed below have 40-hour HAZWOPER or 24-hour training with current refresher status and have read and understood this Health and Safety plan, and agree to abide by its provisions.

Onsite Personnel
Name Signature Company Date

Ninyo & Moore | 360 West Grand Avenue, Escondido, California | 107538004 | July 31, 2017 5710 Ruffin Road | San Diego, California 92123 | p. 858.576.1000 ARIZONA | CALIFORNIA | COLORADO | NEVADA | TEXAS | UTAH ninyoandmoore.com
Geotechnlcal & Environmental Sciences Consultants

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 16, 2024

APPENDIX E
Community Health and Safety Plan

Community Health and Safety Plan
Hidden Glen Dump
Coombsville Road
Napa, California
SWIS No. 28-AA-0028
Napa County Local Enforcement Agency
1195 Third Street, Suite 210 I Napa, California 94559
October 1, 2024 | Project No. 109558001
Geotechnical | Environmental | Construction Inspection & Testing | Forensic Engineering & Expert Witness Geotechnical | Environmental | Construction Inspection & Testing | Forensic Engineering & Expert Witness Geophysics | Engineering Geology | Laboratory Testing | Industrial Hygiene | Occupational Safety | Air Quality | GIS Geophysics | Engineering Geology | Laboratory Testing | Industrial Hygiene | Occupational Safety | Air Quality | GIS Geotechnlcal & Environmental Sciences Consultants

Nathan Diem
Senior Geologist
Stephen J. Waide, CIH, CSP, CIEC, CMC
Principal Environmental Scientist
Community Health and Safety Plan
Hidden Glen Dump
Coombsville Road
Napa, California
SWIS No. 28-AA-0028
Mr. Peter Ex, REHS
Napa County Local Enforcement Agency
1195 Third Street, Suite 210 I Napa, California 94559
October 1, 2024 | Project No. 109558001
5710 Ruffin Road | San Diego, California 92123 | p. 858.576.1000 | www.ninyoandmoore.com NDD/SJW/mp
Geotechnical | Environmental | Construction Inspection & Testing | Forensic Engineering & Expert Witness Geophysics | Engineering Geology | Laboratory Testing | Industrial Hygiene | Occupational Safety | Air Quality | GIS JVin90 & iV\oore Geotechnlcal & Environmental Sciences Consultants

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 i

CONTENTS
1 INTRODUCTION 3
2 SITE DESCRIPTION 3
3 PROPOSED PROJECT ACTIVITIES 4
4 SITE BACKGROUND AND HISTORY 4
5 EVALUATION OF POTENTIAL PUBLIC EXPOSURE TO
HAZARDS 7

5.1 Dust 8

5.2 Odors 8

5.3 Landfill Gases 8

5.3.1 Methane Gas 9

5.3.2 Hydrogen Sulfide 9

5.3.3 Vinyl Chloride 9

5.4 Metals 9

5.5 Petroleum Hydrocarbons 10

5.6 Semi-Volatile Organic Compounds 10

5.7 Organochlorine Pesticides 11

5.8 Polychlorinated Biphenyls 11
6 HAZARD MONITORING AND EQUIPMENT 12

6.1 Air Monitoring Procedures and Methodology 12

6.2 Action Levels for Perimeter Monitoring 13

6.3 Action Plan to Reduce Airborne Concentrations 14
7 CONTROL METHODS 14

7.1 Site Security 14

7.2 Dust and Debris Control 14

7.3 VOCs and Combustible Gases Control 15

7.4 Stockpiled Soil 15

7.5 Quality Assurance and Control Measures 15

7.6 Best Management Practices 15

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 ii 8 EMERGENCY PLANNING 16
9 PUBLIC NOTIFICATION 17
10 REFERENCES 18

FIGURES
Figure 1 – Site Location
Figure 2 – Site Plan

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 3 1 INTRODUCTION
This Master Community Health and Safety Plan (CHSP) provides measures to protect the public and surrounding land uses from potential health hazards during future on-site construction-related activities performed at the Hidden Glen Dump in Napa, California (site, Figure 1). This plan is intended to serve as a master document and shall be implemented during future construction related activities on the site that involve disturbing subsurface materials within or outlying the assumed waste footprint and at locations within approximately 1,000 feet outward from the assumed waste footprint.

A detailed project description, site map indicating the location of proposed work, a list of contact names and phone numbers, and a statement that this CHSP will be implemented during the proposed work will be prepared for each new project and submitted to the Napa County, Solid Waste Local Enforcement Agency (LEA) for their review and approval prior to conducting subsurface construction activities at the site.
2 SITE DESCRIPTION
The waste disposal site (WDS) is listed as “Hidden Glen Dump” in the CalRecycle Solid Waste Information System (SWIS) database and assigned SWIS No. 28-AA-0028. According to the database, the dump is listed as an unpermitted, closed, solid waste disposal site (WDS). The City-owned property referred to as “Parcel A” corresponds to a 2.18-acre area and is assigned Napa County Assessor Parcel Number (APN) 045-411-022-000 (Figure 2). The dump is located in a residential setting with wastes occurring at the previously capped portion of the dump, “buffer zone” and at adjacent residential properties downslope to the north, west, and south and generally upslope to the east. Adjacent residential properties are not separated by a road or other features. A cemetery is located across Pascale Place to the west.

The dump has three relatively recently constructed Landfill Gas (LFG) monitoring wells referred to as MW-1 through MW-3 (Figure 3). The wells were constructed in December 2020 and are monitored quarterly. The wells are dual and triple completions; MW-1 and MW-2 are constructed with screened intervals at 5 to 10 feet, 15 to 20 feet and 25 to 35 feet and MW-3 is constructed with two screened intervals at 5 to 10 feet and 15 to 20 feet.

Site: Hidden Glen Dump
Coombsville Road
Napa, California
(SWIS No. 28-AA-0028)
GIS Coordinates Latitude: 38.2977 Longitude: -122.2679

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 4 Land Owner City of Napa
955 School Street
Napa, California 94559
Site Health and To Be Determined by
Safety Manager (SHSM): General Contractor
Community Health
and Safety Manager
(CHSM): To Be Determined by the City
Oversight Agency: Napa County Solid Waste Program LEA
1195 Third Street, Suite 210
Napa, California 94559
Contact: Mr. Peter Ex
(707) 253-4419
3 PROPOSED PROJECT ACTIVITIES
Future work at the site that would require implementation of this plan includes construction-related activities that involve disturbing the subsurface materials at the site including but not limited to grading, subsurface excavation/trenching activities associated with maintenance/repairs or new construction.

Prior to conducting subsurface construction activities at the site, the following should be submitted to the LEA for their review and approval:
• a detailed project description,
• site map indicating the location of proposed work,
• the name and contact information for the contractor or agency performing the work, SHSM, and the CHSM, and
• a statement that this CHSP will be implemented during the proposed work. 4 SITE BACKGROUND AND HISTORY
Initially the dump was an excavated quarry that operated into the 1940s. Reportedly, groundwater was encountered when the quarrying operations reached at a depth of about 70 to 80 feet (below ground surface (bgs). However, reportedly subsequent subsurface investigations as summarized in the McClaren-Hart (1990) Closure Plan indicated that based on borings advanced within the waste disposal pit area, the waste thicknesses range from approximately 5 to 24 feet with an average depth of 20 feet. Reportedly, the quarry was abandoned due to the presence of groundwater. Sometime after quarry operations ended, the excavation was used as

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 5 a general garbage dump by a private operator. Reportedly, “garbage” was dumped and then burned “and spread as a landfill.” It was stated that it was possible that “old” automobiles from a local demolition derby were also abandoned at the dump. In the early l960's, the dump reportedly was abandoned when the South County landfill became operational. The City reportedly began using the Hidden Glen Dump to dispose tree prunings and brush, along with asphalt and concrete wastes. The brush and prunings were reportedly burned “and spread.” Several closure plans (aka remedial action plans) were previously prepared for the dump and remedial action activities were conducted to close the site. ENGEO (1988) prepared a closure plan consisting of capping the waste disposal site “in place.” In 1990, Harding Lawson Associates (HLA) (1990) prepared an addendum to the closure plan that maintained the planned “in-place capping” of the dump. In April 2000 McClaren-Hart prepared a Closure Plan for the Hidden Glen Dump (McClaren-Hart, Inc, 2000) that was generally consistent with the previous 1988 ENGEO and 1990 HLA closure plans and similarly proposing capping the waste disposal site “…in place and dedicating the site as open space as part of a planned residential development of the surrounding site.” The closure plan proposed to cap in place the dump and reportedly “…gain agency concurrence for closure, which is sought by the land owner to allow him to proceed with planned residential development of the overall 14-acre site.” Reportedly the 1990 McClaren-Hart Closure Plan report was prepared as an addendum to the 1988 Closure Plan.

In general, the McClarren-Hart Closure Plan described methods proposed to cap in place the dump and obtain regulatory agency concurrence for closure which was being sought by the land owner to allow them to proceed with the planned residential development of the overall 14-acre site, a portion of which included the dump. Post closure activities were indicated as consisting of a 5-year cap and methane monitoring program even though methane was not expected to be encountered at levels of environmental concern.

In June 2000 Harding Lawson conducted surface sampling, followed by HSI GeoTrans (GeoTrans) performing follow up soil sampling in November 3, 2000 “…to further revaluate lead concentrations in surface soil outside the perimeter of the landfill.” GeoTrans stated that the purpose of the “follow-up soil sampling” was to further evaluate concentrations of lead in surface “soils” at three proposed parcels (7, 10 and 11) reportedly related to initial screening level “soil” sampling performed in June 2000 that indicated lead concentrations in “surface soil” above 200 ppm at each of these three parcels. Both of the investigations indicated elevated lead concentrations (greater than 200 parts per million [ppm] lead) at locations outlying the assumed waste disposal area/proposed area to be capped.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 6 Geotrans (Geotrans) stated that while excavating the western "debris field" a “trench feature” filled with “landfilled debris” was discovered. It was reported that the “trench” extended up to approximately 10 feet deep, and measured approximately 15 feet in width and 60 feet in length. Geotrans indicated that the material from this “trench area” was excavated to a bedrock base and placed into the interior of the landfill. Geotrans proposed to collect five confirmation samples of “rock material” across the base of the excavated area to verify that there is no impact in this area, and to allow this area to be considered "clean" and “outside the perimeter of the landfill.” Geotrans stated that this area is slated to be an easement area for access to the future closed waste disposal site and will not be within a proposed parcel or lot.

In January 2002, Geotrans submitted a documentation report of the waste cap construction on behalf of the Napa Garbage Service that included as-built drawings, liner test results, compaction test results, site photographs, and a description of the work performed. It was stated that the “landfill” cap was constructed in accordance with the design specifications and closure plan requirements. Geotrans stated that the closure was performed with oversight and direction from the Water Board, CIWMB and the LEA and in general accordance with the April 6, 2000 closure plan prepared by McLaren/Hart, Inc. titled, “Closure Plan, Hidden Glen Landfill, Napa, California” as amended by the December 6, 2000 letter prepared by Geotrans titled, “Addendum to April 6, 2000 Hidden Glenn Landfill Closure Plan, Napa, California.” GeoTrans stated that the construction documentation report indicated that “landfill closure” included importing and stockpiling clean fill material for use as foundation fill and protective soil cover; clearing and grubbing the waste area surface; placing and grading foundation fill soils over the waste materials; installing a cap system consisting of a geosynthetic clay liner (GCL), 80-mil high density polyethylene (HDPE ) layer, and geocomposite drainage layer; placing protective soils and top soil over the cap; placing a hydroseed mixture on the topsoil; and installing surface water drainage and erosion control features.

Landfill closure activities were reported as being conducted from June 28 to November 28, 2001.

The closure report (aka remedial action) appears to have provided the required documentation and supporting information pertaining to the activities conducted at the dump related to constructing the waste cap. The closure report in conjunction with other documents also provided information about the removal of wastes outlying the cap at two “debris fields” (one being the waste trench) previously located on three lots (6, 9 and 10) and four areas of lead impacted “soils” on three lots (7, 10 and 11) and the on-site reconsolidation of these materials in the capped area. Furthermore, t was stated that the results were communicated to regulatory agency staff that concurred “no further action was required.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 7 Beginning in September 2018, Langan conducted subsurface site investigations (drilling and sampling) of residential properties at Lots 6, 7, 8, 9 and 10, outlying the capped portion of the Hidden Glen Dump. Langan indicated that the purpose of their investigations was to collect “subsurface information” to develop a plan for remedial action “to address debris impacts in shallow soil on the five lots and, if needed, on adjacent areas between the lots and the landfill footprint.” Results of their investigations indicated the presence of relatively shallow wastes extending onto the residential properties. These wastes contain elevated lead concentrations at some locations. The results of their investigations indicate that the lateral extent of the waste disposal site extends beyond the area that was capped.
5 EVALUATION OF POTENTIAL PUBLIC EXPOSURE TO HAZARDS
During construction activities, care must be taken to protect surrounding receptors, such as the adjacent residential properties. Community exposures to hazards from site activities and/or releases that may migrate to human and environmental off-site receptors will be minimized.

Future project activities that would require implementation of this plan include construction-related activities that disturb the subsurface environment, which includes, but is not limited to, grading, subsurface excavation/trenching activities associated with maintenance/repairs or new construction, and other subsurface disturbances at and/or within approximately 1,000 feet from the waste footprint boundary.

Future construction work may be conducted within or in close proximity to the assumed waste footprint and areas of potential human health and environmental impact from the buried waste include the site and off-site areas approximately 1,000 feet outward of the assumed waste footprint. There is potential for encountering landfill wastes if construction activities are within the assumed waste footprint. There is also potential to encounter LFG during future construction activities within or outlying the assumed waste footprint; however, based on the active LFG extraction system operating at the site, there is a low likelihood of encountering high concentrations of LFG in areas outlying the waste footprint, but high concentrations of landfill gas could be encountered in areas located within the waste footprint. The potential public hazards and nuisances from future subsurface construction activities include:
• organic vapors,
• landfill gases,
• airborne contaminant particles and dust, and
• odors.

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 8 Based on historical records elevated lead and total petroleum hydrocarbons (TPH) concentrations were detected at the dump site and on adjacent properties. Other constituents of potential concern (COPCs) include landfill gas, metals, total petroleum hydrocarbons (TPH), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and volatile and semi-volatile organic compounds (VOCs and SVOCs, respectively). PCBs, OCPs, VOCs and SVOCs were detected in soil samples at concentrations below their respective Region Water Quality Control Boards Environmental Screening Levels and may be present at the site.

Chemical characteristics of the constituents of potential concern are described in the following sections. Although not directly relevant to community exposure, occupational exposure limits, where available, are given for informational purposes and, if measured at the source, would be protective of the community. The perimeter monitoring, action levels, and the required notifications and control measures, if action levels are exceeded, are described in further detail in the following sections.

For the purposes of this CHSP, the monitoring points of compliance will be along the perimeter of the active work area, unless otherwise determined by the CHSM, or designee, based on actual site conditions and activities. The CHSM will be a Certified Industrial Hygienist.

5.1 Dust
Material removal, stockpiling of bulk soil and other materials, handling of potentially contaminated soil or other items, and general excavation and grading can generate airborne dust that can become a nuisance or a hazard to nearby sensitive receptors. In addition, certain contaminants can adhere or adsorb to various particles in dust, resulting in potential offsite impacts. Visible dust will be monitored and controlled at the site by the Contractor. The Project Environmental Consultant will monitor dust at the site perimeter during soil disturbance activities, if indications of possible contamination are encountered.

5.2 Odors
If landfill wastes are encountered, odors may be present as a result of degradation of buried organic wastes in the landfill. Odor monitoring by qualitative (olfactory) and semi-quantitative (photoionization detector [PID]) methods and by LFG monitoring will be performed to identify potential odor issues.

5.3 Landfill Gases
Because of the possibility of decomposition of organic materials buried at the site (e.g., municipal solid waste), a discussion of landfill gases is necessary. Decomposition of organic

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 9 material results in the production of several gases that may present a safety and health concern.

5.3.1 Methane Gas
Methane gas has been monitored at the site since December 2020 and is currently monitored on a quarterly basis. Methane monitoring results have been below regulatory limits during all monitoring events. Methane gas may be encountered during excavation activities. Methane is odorless and non-toxic, but can present an explosive hazard in high concentrations, can act as a simple asphyxiant (can displace oxygen) in low-lying areas or confined spaces, and may be an indicator of the presence of other potentially hazardous landfill gases. Methane will continue to be monitored as an explosive gas.

5.3.2 Hydrogen Sulfide
Hydrogen sulfide (H2S) is a colorless, heavier-than-air gas with a characteristic odor. (Note that desensitization can occur, i.e., the inability to “smell” the odor, resulting in increased danger of overexposure.) H2S is commonly found at landfills as a result of waste decomposition. It can be toxic or fatal if inhaled in high concentrations.

5.3.3 Vinyl Chloride
Vinyl chloride results from the decomposition of chlorinated materials such as plastics and solvents. Vinyl chloride is a recognized human carcinogen. The Occupational Safety and Health Administration (OSHA) standard for vinyl chloride (to occupational workers) established an exposure limit of 1 ppm as a time-weighted average (TWA) and 5 ppm as a short-term exposure limit (i.e., 15 minutes). The action levels established for this site are designed to adequately protect the public from fugitive emission of this toxic gas. In the unlikely event that site conditions indicate the need to monitor worker exposures to vinyl chloride, perimeter monitoring will be initiated. The CHSM will determine the type and frequency of monitoring based on site conditions.

5.4 Metals
Elevated concentrations of lead at the site have been documented during previous site assessments activities. Although metal and metal ions do not present volatility or flammability problems, they can present acute and chronic effects if the host material is inhaled in the form of dust or fumes. Metal ions can cause irritation of mucous membranes and lung tissues and some metals such as lead are suspected carcinogens. Public exposure to metals in the burned waste

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 10 and soil by dermal contact or ingestion is not likely. Therefore, this plan addresses potential exposure by inhalation of dust containing metals generated by site activities.

Lead is the primary metal of concern. It is a toxic heavy metal and a suspected carcinogen that may be encountered in inorganic or organic forms. The Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL)- time weighted average (TWA) for lead in air is 0.05 milligram per cubic meter (mg/m3). Visible dust will be monitored and controlled during construction activities as described in Section 7.

5.5 Petroleum Hydrocarbons
TPHmo and TPHd were detected in soil samples in adjacent properties (Langan, 2019). TPH is a term used to describe a large family of several hundred chemical compounds that originally come from crude oil. TPH is a mixture of chemicals, but they are all made mainly from hydrocarbons.

Some chemicals that may be found in TPH are hexane, jet fuels, mineral oils, benzene, toluene, xylenes, naphthalene, and fluorene, as well as other petroleum products and gasoline components.

Some of the TPH compounds can affect your central nervous system. One compound can cause headaches and dizziness at high levels in the air. Another compound can cause a nerve disorder called "peripheral neuropathy," consisting of numbness in the feet and legs. Other TPH compounds can cause effects on the blood, immune system, lungs, skin, and eyes.

Animal studies have shown effects on the lungs, central nervous system, liver, and kidney from exposure to TPH compounds. Some TPH compounds have also been shown to affect reproduction and the developing fetus in animals. The International Agency for Research on Cancer (IARC) has determined that one TPH compound (benzene) is carcinogenic to humans.

IARC has determined that other TPH compounds (benzo[a]pyrene and gasoline) are probably and possibly carcinogenic to humans. Most of the other TPH compounds are considered not to be classifiable by IARC.

5.6 Semi-Volatile Organic Compounds
Semi-volatile organic compounds (SVOC) have been detected in soil samples below regulatory screening levels from adjacent properties and include bis (2-ethylhexyl), phthalate, and pyrene (Langan, 2019). Although SVOCs have not been detected at elevated concentrations, SVOCs may be encountered during excavation actives and for the purpose of this CHSP, hazards are explained below.

SVOCs area organic compound which have a boiling point higher than water and which may vaporize when exposed to conditions above room temperature. Significant airborne levels of

Ninyo & Moore | Hidden Glen Dump, Coombsville Road, Napa, California | 109558001 | October 1, 2024 11 SVOCs are not typical during fieldwork however they can be present in airborne dust. SVOCs include phenols and PAHs. Short-term effects of phenol exposure include respiratory irritation, headaches, and burning eyes. Chronic effects of high exposures include weakness, muscle pain, anorexia, weight loss, and fatigue; effects of long-term low-level exposures include increases in respiratory cancer, heart disease, and effects on the immune system. PAHs are produced from coal tar and other sources and are used in a variety of industrial products. PAH is a recognized human carcinogen. Studies in animals have also shown that PAHs can cause harmful effects on skin, body fluids, and the body's system for fighting disease after both shortand long-term exposure; however, these effects have not been reported in people. The current OSHA PEL is 0.2 milligrams per cubic meter (mg/m3
); however, exposure by any route to PAH
and other recognized human carcinogens will be maintained at the absolute practicable minimum level. Exposure to SVOCs are expected to be adequately controlled with the designated action levels for airborne vapor and dust.

5.7 Organochlorine Pesticides
OCPs were detected in soil samples below regulatory screening levels in adjacent properties and include endosulfan, p,p-DDD, p,p-DDE, and p,p-DDT, aldrin, alpha- BHC, and dieldrin (Langan, 2019). As with PAHs above, action levels for lead and total dust will serve to keep exposure to OCPs well below recognized exposure limits and should eliminate offsite impacts.

5.8 Polychlorinated Biphenyls
PCBs have been detected in soil samples below regulatory screening levels. Although PCBs are not expected at elevated concentrations, for the purposes of this CHSP, hazards are described below.

PCBs, also referred to as aroclors, are synthetic industrial products which have been commonly used as cooling fluid and for electrical insulation. PCBs are common contaminants of oily type waste and are found around railroad tracks and in industrial areas and dumps. PCBs are recognized environmental pollutants and suspected human carcinogens.

The United States Environmental Protection Agency (EPA) currently classifies PCBs as a Class B2, or probable, human carcinogen. Skin exposure may contribute significantly to uptake of these chemicals, and therefore all skin exposure should be strictly avoided. Work involving exposure to PCBs above the atmospheric action level or in contact materials exceeding 100 micrograms per gram may require special medical evaluation and approval of the SHSO.

PCBs are not volatile and exposure will be controlled by limiting airborne dust.