Riverside City Council
September 5, 2023

P1. Other Identifier:
*P2. Location:  Not for Publication  Unrestricted *a. County: Riverside and (P2b and P2c or P2d. Attach a Location Map as necessary.)

*b. USGS 7.5' Quad: Riverside West Date: 1980 T4S ; R 5W ; ¼ of ¼ of Sec 4 ; S.B.B.M.

c. Address: n/a City: Riverside Zip:

d. UTM: Zone: 11S; 46246mE/ 3754638 mN (G.P.S.) NAD 83

e. Other Locational Data:
(e.g., parcel #, directions to resource, elevation, etc., as appropriate) APN: 230-233-013; 230-245-013; 230-245-015; 230-253-010. This site is located on the north side of the BNSF railroad tracks, on the south side of Rail Road Avenue and between Madison Avenue and Jefferson Streets in Riverside.

*P3a. Description: (Describe resource and its major elements. Include design, materials, condition, alterations, size, setting, and boundaries) This site contains the concrete foundation remnant of the former Casa Blanca Station and three mature ornamental landscape palm trees. The remaining slab measures approximately 36’ × 21’ and is located adjacent to the north side of the BNSF railroad tracks. The foundation appears to have been poured in three sections separated by wooden beams. The Casa Blanca Station was removed in 1967. The foundation remains are deteriorating.

*P3b. Resource Attributes: (List attributes and codes) AH02 foundation; AH03 Landscaping

*P4. Resources Present: Building Structure Object Site District Element of District Other (Isolates, etc.)

P5b. Description of Photo: (View,
date, accession #)
Overview, facing east 3/2017

*P6. Date Constructed/Age and
Sources: Historic
Prehistoric Both

*P7. Owner and Address:

*P8. Recorded by:
(Name,
affiliation, and address)
Gini Austerman
LSA Associates, Inc.
1500 Iowa Avenue, Suite 200
Riverside, CA 92507

*P9. Date Recorded:

March 2017

*P10. Survey Type:
(Describe)
Intensive-level CEQA compliance

*P11. Report Citation:
(Cite survey report and other sources, or enter "none.") 2017 Austerman Cultural Resources Assessment for the Harley Davidson Storage Project; City and County of Riverside, CA.

*Attachments: NONE Location Map Sketch Map Continuation Sheet Building, Structure, and Object Record Archaeological Record District Record Linear Feature Record Milling Station Record Rock Art Record Artifact Record Photograph Record  Other
(List):

P5a. Photo or Drawing (Photo required for buildings, structures, and objects.)

PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices LSA-ADK-H-1
·|}þ91

JEFFERSON STREET

INDIANA AVENUE

LINCOLN AVENUE
I:\ADK1601\Reports\Cultural\DPR\DPRlocation_LSA-ADK1701-H-1.mxd (3/29/2017) DPR 523J (1/95) *Required Information

*Map Name: USGS 7.5' Quad, Riverside West *Scale: 1:24000 *Date of Map: 1980 *Resource Name or # (Assigned by recorder) LSA-ADK-H-1 Primary #
HRI #
Trinomial
State of California - Resource Agency

DEPARTMENT OF PARKS AND RECREATION

LOCATION MAP
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices DPR 523C (Rev. 1/1995)(Word 2/2015)
State of California  Natural Resources Agency Primary # DEPARTMENT OF PARKS AND RECREATION Trinomial

ARCHAEOLOGICAL SITE RECORD

*A1. Dimensions: a. Length: 36 feet  b. Width: 21 feet Method of Measurement:  Paced  Taped  Visual estimate  Other:

Method of Determination (Check any that apply.):  Artifacts  Features  Soil  Vegetation  Topography  Cut bank  Animal burrow  Excavation  Property boundary  Other (Explain):

Reliability of Determination:  High  Medium  Low Explain:

Limitations (Check any that apply):  Restricted access  Paved/built over  Site limits incompletely defined  Disturbances  Vegetation  Other (Explain):

A2. Depth:  None  Unknown Method of Determination:
*A3. Human Remains:  Present  Absent  Possible  Unknown (Explain):

*A4. Features (Number, briefly describe, indicate size, list associated cultural constituents, and show location of each feature on sketch map.):

This site contains three features. These are the concrete foundation remnant of the former Casa Blanca Station; the remaining slab measures approximately 36 × 21 feet and is located on the north side of the BNSF railroad tracks. The foundation appears to have been poured in three sections separated by wooden beams. The Casa Blanca Station was demolished in 1967. Located east of the foundation are three palm trees which are likely associated with the Casa Blanca Station.

*A5. Cultural Constituents (Describe and quantify artifacts, ecofacts, cultural residues, etc., not associated with features.): None were noted.

*A6. Were Specimens Collected?  No  Yes (If yes, attach Artifact Record or catalog and identify where specimens are curated.) *A7. Site Condition:  Good  Fair  Poor (Describe disturbances.): The Casa Blanca Station has been removed, the site has been graded and partially covered in gravel.

*A8. Nearest Water (Type, distance, and direction.): Upper Riverside Canal, approximaltey 285 feet northwest. *A9. Elevation: 860 feet amsl
A10. Environmental Setting (Describe culturally relevant variables such as vegetation, fauna, soils, geology, landform, slope, aspect, exposure, etc.): The site is located in a vacant lot on the north side of the BNSF railroad tracks, south of Railroad Avenue.

A11. Historical Information: The foundation is the remains of the Casa Blanca Station, built in 1897 and demolished in 1967.

The station was one of four BNSF railroad stations that served the Riverside area.

*A12. Age:  Prehistoric  Protohistoric  1542-1769  1769-1848  1848-1880  1880-1914  1914-1945  Post 1945  Undetermined
Describe position in regional prehistoric chronology or factual historic dates if known:

A13. Interpretations (Discuss data potential, function[s], ethnic affiliation, and other interpretations): The foundational remains of the Casa Blanca Station do not retain adequate integrity to meet the criteria for listing in the National Register of Historic Places, the Californian Register of Historlcal Resources or for local designation.

A14. Remarks:

A15. References
(Documents, informants, maps, and other references):

A16. Photographs (List subjects, direction of view, and accession numbers or attach a Photograph Record.):

Original Media/Ne gatives Kept at:
*A17. Form Prepared by: Gini Austerman Date: 3/27/2017 Affiliation and Address: LSA Associates, Inc. 1500 Iowa Avenue, Suite 200, Riverside, CA 92507

*Required information
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices

Drawn By: Date:
*Resource Name or # (Assigned by recorder) LSA-ADK-H-1 Primary #
HRI #
Trinomial
State of California - The Resources Agency

DEPARTMENT OF PARKS AND RECREATION

SKETCH MAP
March 20, 2017Gini Austerman
I:\ADK1601\Reports\Cultural\DPR\DPR_Sketch_LSA-ADK1701-H-1.mxd (3/29/2017) DPR 523K (1/95) *Required Information
Legend
Site Boundary
!( Sites
0 20 40
Feet
S!!N
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices

Environmental Initial Study/Mitigated Negative Declaration # PR-2021-001197

APPENDIX E

Geotechnical Investigation for Proposed
Madison Flats Multi-Family Residential Development
Southwest of Madison Street and Railroad Avenue,
Riverside, California
(Geotechnical Investigation)
(Leighton and Associates, Inc., December 2022)

PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices

GEOTECHNICAL INVESTIGATION

PROPOSED MADISON FLATS

MULTI-FAMILY RESIDENTIAL DEVELOPMENT

SOUTHWEST OF MADISON STREET

AND RAILROAD AVENUE

RIVERSIDE, CALIFORNIA

Prepared For GILBANE DEVELOPMENT COMPANY
1100 NORTH GLEBE ROAD, SUITE 1000
ARLINGTON, VIRGINIA 22201
Prepared By LEIGHTON AND ASSOCIATES, INC.
10532 ACACIA STREET, SUITE B-6
RANCHO CUCAMONGA, CA 91730

Project No. 13693.001
December 5, 2022
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices

December 5, 2022

Project No. 13693.001

Gilbane Development Company
1100 North Glebe Road, Suite 1000
Arlington, Virginia 22201

Attention: Mr. Blaise Rastello
Development Director/Affordable Housing

Subject: Geotechnical Investigation
Proposed Madison Flats Multi-Family Residential Development Southwest of Madison Street and Railroad Avenue
Riverside, California

In response to your request, Leighton and Associates , Inc. (Leighton) has conducted this geotechnical investigation for the proposed Madison Flats m ulti-family residential development located southwest of Madison Street and Railroad Avenue in the City of Riverside, California. The purpose of this exploration has been to evaluate the general geotechnical conditions at the site with respect to the proposed development and to provide preliminary geotechnical recommendations for design and cons truction of the project.

Based on this geotechnical investigation, construction of the proposed multi -family residential development is feasible from a geotechnical standpoint. The most significant geotechnical issues with respect to the project are those related to the potential for strong seismic shaking and potentially compressible soil . Good planning and design of the project can limit the impact of these constraints. This report presents our preliminary findings, conclusions, and geotechnical recommendations for the project.

PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 2 -
We appreciate the opportunity to work with you on this project. If you have any questions regarding this report, please call us at your convenience.

Respectfully submitted,

LEIGHTON AND ASSOCIATES, INC.

Jason D. Hertzberg, GE 2711
Principal Engineer

Jose Tapia, PE 91630
Project Engineer

Steven G. Okubo, CEG 2706
Associate Geologist

AA/JAT/JDH/SGO/rsm

Distribution: (1 ) Addressee
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices 13693.001

- ii -

TABLE OF CONTENTS
Section Page

1.0 INTRODUCTION ............................................................................................... - 1 -

1.1 Site Location and Description ......................................................................... - 1 -

1.2 Proposed Development .................................................................................. - 1 -

1.3 Purpose .......................................................................................................... - 2 -

1.4 Scope of Work ................................................................................................ - 2 -

2.0 FINDINGS ......................................................................................................... - 5 -

2.1 Regional Geologic Setting .............................................................................. - 5 -

2.2 Subsurface Soil Conditions ............................................................................ - 5 -

2.2.1 Compressible and Collapsible Soil .......................................................... - 6 -

2.2.2 Expansive Soil ......................................................................................... - 6 -

2.2.3 Sulfate Content ........................................................................................ - 7 -

2.2.4 Resistivity, Chloride and pH ..................................................................... - 7 -

2.3 Groundwater .................................................................................................. - 7 -

2.4 Infiltration ....................................................................................................... - 8 -

2.5 Faulting and Seismicity .................................................................................. - 9 -

2.6 Secondary Seismic Hazards .......................................................................... - 9 -

2.6.1 Liquefaction Potential .............................................................................. - 9 -

2.6.2 Seismically Induced Settlement ............................................................. - 10 -

2.6.3 Slope Stability and Seismically Induced Landslides .............................. - 11 -

3.0 CONCLUSIONS AND RECOMMENDATIONS ............................................... - 12 -

3.1 General Earthwork and Grading ................................................................... - 12 -

3.1.1 Site Preparation ..................................................................................... - 12 -

3.1.2 Overexcavation and Recompaction ....................................................... - 13 -

3.1.3 Fill Placement and Compaction ............................................................. - 14 -

3.1.4 Import Fill Soil ........................................................................................ - 14 -

3.1.5 Shrinkage and Subsidence .................................................................... - 14 -

3.1.6 Rippability and Oversized Material ........................................................ - 15 -

3.2 Shallow Foundation Recommendations ....................................................... - 15 -

3.2.1 Minimum Embedment and Width ........................................................... - 16 -

3.2.2 Allowable Bearing .................................................................................. - 16 -

3.2.3 Lateral Load Resistance ........................................................................ - 16 -

3.2.4 Increase in Bearing and Friction - Short Duration Loads ....................... - 17 -

3.3 Recommendations for Slabs-On-Grade ....................................................... - 17 -

3.4 Seismic Design Parameters ......................................................................... - 18 -

3.5 Retaining Walls ............................................................................................ - 20 -

3.6 Pavement Design ......................................................................................... - 21 -

3.7 Temporary Excavations ............................................................................... - 23 -

3.8 Trench Backfill .............................................................................................. - 23 - PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices 13693.001

- ii -

3.9 Surface Drainage ......................................................................................... - 24 -

3.10 Infiltration Recommendations ................................................................... - 24 -

3.11 Sulfate Attack and Corrosion Protection ................................................... - 27 -

3.12 Additional Geotechnical Services.............................................................. - 27 -

4.0 LIMITATIONS ..................................................................................................... - 29 -

Figures (Rear of Text)

Figure 1 - Site Location Map
Figure 2 - Boring Location Map
Figure 3 - Regional Geology Map
Figure 4 - Regional Fault and Historical Seismicity Map Figure 5 - Retaining Wall Backfill and Subdrain Detail

Appendices

Appendix A - References
Appendix B - Geotechnical Exploration Logs
Appendix C - Laboratory Test Results
Appendix D - Summary of Seismic Analyses
Appendix E - General Earthwork and Grading Specifications

PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 1 -

1.0 INTRODUCTION

1.1 Site Location and Description

The approximately 4.15- acre si te is located southwest of Madison Street and Railroad Avenue within the City of Riverside, California (see Figure 1, Site Location Map). The site is bounded to the northwest and southwest by Railroad Avenue, to the northeast by Madison Street, and to the southeast by the BNSF Railroad Tracks. Residential homes lie to the northwest beyond Railroad Avenue and to the southeast beyond the existing railroad tracks.

The property is elongated and roughly rectangular in shape and currently undeveloped. The property is comprised of Assessor’s Parcel Numbers (APNs) 230-233-013-03, 230- 245-015-2, 230- 245-013-0, and 230- 253-010-2. The site contains gravel on the surface, a few palm trees, small sheds on the northeast end, and trace scattered construction debris that appear to be associated with the railroad.

Based on a review of historical aerial photographs , the site has been undeveloped since at least 1948. Two dirt roads appear to have crossed the southern portion of the site prior to the construction of Railroad Avenue sometime between 1967 and 1985 (NETR, 2022). The site is relatively flat with elevations from 857 and 863 feet above mean sea level (msl) draining gently towards the northwest.

1.2 Proposed Development

Based on correspondence with Psomas and the provided Madison Flats City Submission packet prepared by Studio One Eleven, dated October 14, 2021, we understand that the proposed project will include the construction of 27, two- to three-story multi-family buildings. The proposed buildings are generall y closely spaced together with parking areas and courtyards separating groups of buildings. Building footprints range from approximately 1,100 square feet (SF) to 1,500 SF in plan area. Approximately 2.61 acres are slated for senior residential housing consisting of 75 one- and two-bedroom units. Approximately 1.54 acres are slated for multi -family residential housing consisting of 45 one to three- bedroom units. Also planned, are nine courtyard areas , two surface parking lots PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 2 -
with approximately 76 designated parking spaces, associated landscaping, amenity spaces, associated dry and wet utilities, and three drywell locations for water quality infiltration.

A conceptual grading plan was not available at the time of this study but based on current surface el evations and no underground parking planned for design, we anticipate relatively shallow cuts and fills to achieve design grade (generally on the order of 5 feet or shallower for the proposed building).

1.3 Purpose

The purpose of this study has been to evaluate the general geotechnical conditions at the site with respect to the proposed development and provide preliminary geotechnical recommendations for design and construction of the proposed project.

1.4 Scope of Work

Our geotechnical investigation included exploration with hollow- stem auger borings, infiltration testing, laboratory testing , and geotechnical analysis to evaluate existing site conditions and to develop the recommendations contained in this report. Our scope of work has included the following tasks:

• Background Review: We reviewed available geotechnical reports, literature, geotechnical/geologic maps, and historical aerial photographs relevant to the planned improvements and available from our in-house library.

• Utility Coordination : We conta cted DigAlert (811) at least 48 hours prior to drilling borings to locate major utilities, underground services, and easements.

• Field Exploration: A total of seven (7) hollow-stem auger borings ( LB-1 through LB-7) were drilled , logged, and sampled at locations throughout the site to evaluate subsurface conditions. These hollow-stem auger borings were drilled to depths ranging from 21 ½ to 51½ feet below the existing ground surface (bgs) by a subcontracted truck-mounted drill rig. During drilling of our borings, California-Modified split -spoon ring or Standard Penetration Test (SPT) sample rs were used to collected soil from each sampling interval for geotechnical laboratory testing and analyses. Bulk samples of representative PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 3 -
soil types were also collected for geotechnical laboratory testing. Each boring was logged by a member of our technical staff under supervision of a licensed Civil Engineer.

Drilled borings were backfilled with soil cuttings. Logs of the drilled borings are provided in Appendix B. B oring locations are shown on the accompanying Figure 2, Boring Location Map.

• Infiltration Testing : Well permeameter tests were performed within three additional borings drill ed at the site (IT -1 through IT -3) to estimate soil infiltration characteristics onsite. These tests were located based on the KMZ file provided by the project Civil Engineer, Psomas, which indicated three proposed drywell locations. Depths of these drywells were not provided at the time of our investigation, and the depths were selected based on the soil types encountered during drilling . T est zones for each well permeameter reached maximum depths ranging from approximately 15 feet to 48½ feet bgs. In-situ infiltration testing was performed in general accordance with Riverside County guidelines. The results of the infiltration tes ting are presented in Appendix B. Discussion of the test results and infiltration rate are presented in Section 2.4.

• Geotechnical Laboratory Testing : Geotechnical laboratory tests were conducted on relatively undisturbed and bulk soil samples obtained during our field investigation. This laboratory testing program was designed to evaluate engineering characteristics of site soils. Laboratory tests conducted during this investigation include:

- In situ moisture content
- Sieve analysis for grain-size distribution
- Atterberg Limits
- Expansion Index
- Collapse potential
- Consolidation
- Modified proctor compaction test
- R- Value
- Water-soluble sulfate concentration
- Resistivity, chloride content and pH
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 4 -
The laboratory test results are presented in Appendix C.

• Engineering Analysis: Data obtained from our background review, field exploration, and geotechnical laboratory testing was evaluated and analyzed to develop geotechnical conclusions and provide preliminary recommendations presented in this report by a Professional Engineer and Certified Engineering Geologist in accordance with the standard of care provided by our industry in this area for this type of project.

• Report Preparation: Results of our preliminary geotechnical investigation have been summarized in this report, presenting our findings, conclusions and preliminary geotechnical recommendations for earthwork and remedial grading, fill placement, foundation design parameters, retaining wall, pavement design, and cement type.

PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 5 -

2.0 FINDINGS

2.1 Regional Geologic Setting

The site is located in the northern Peninsular Ranges geomorphic province of southern California along the southern margin of the Chino Basin. Cretaceous igneous rocks of the southern California Batholith underlie and crop out in this area of the Peninsular Ranges. Northwest-trending, right-lateral, strike-slip faults dominate the structure of the Peninsular Ranges. Major structural features within this region include: the Whittier-Elsinore fault zone and the Santa Ana Mountains to the southwest, the Chino- Central Avenue f ault and Puente Hills to the west, and the San Jacinto fault zone to the northeast. The closest active fault to the site is related to the San Jacinto fault zone located approxim ately 11.1 miles northeast of the project site.

The site rests on generally flat terrain underlain by late to middle Pleistocene old alluvial fan soils (Morton et al., 2002). These deposits ty pically consist of sandy sediment. Regional geologic conditions are depicted on Figure 3, Regional Geology Map.

2.2 Subsurface Soil Conditions

The site has been mapped as being underlain by Quaternary old alluvial fan deposits (Qof; see Figure 3, Regional Geology Map). We encountered artificial fill in the upper 1 to 2 ½ feet in our borings underlain by native old alluvial fan deposits. Because a geotechnical report of rough grading summarizing grading observations and testing of the previously placed fill was not available at the time of this report, existing onsite fill materials have been considered undocumented.

Based on our observation during drilling, undocumented artificial fill encountered consisted of scattered gravel on the surface over very loose to loose silty sands and very stiff sandy silts. Native old al luvial fan deposits observed i n our borings to explored depths primarily consisted of silty sands with interbedded layers of clean sands, silts, clayey sands, and clays. Sands in the upper 10 feet were generally described as very loose to medium dense soils and light brown to brown in color. In general, the native old alluvial fan deposits became denser with depth. D eeper native sands encountered w ere generally described as medium dense to very dense, light brown to orang ish brown to explored depths. The PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 6 -
interbedded layers of native clays and silts were generally described as stiff to hard with layer thicknesses as much as 10 feet in vertical dimension.

Soils within the upper 10 feet generally had in situ moisture contents ranging from 2 to 15 percent by weight, with in situ dry densities of 111 to 122 pcf.

2.2.1 Compressible and Collapsible Soil

Soil compressibility refers to a soil’s potential for settlement when subjected to increased loads as from a fill surcharge. Based on our investigation, the near surface alluvial soil encountered is generally considered slightly to moderately compressible. Partial removal and recompaction of this material under shallow foundations is recommended to reduce the potential for adverse total and differential settlem ent of the proposed improvements to acceptable levels.

Collapse potential refers to the potential settlement of a soil under existing stresses upon being wetted. A collapse test performed on a near -surface sample resulted in a moderate collapse potential. Based on the relatively dense nature of the underlying soils encountered below 5 feet in our borings, and our recommendations to remove both artificial fill and loose native alluvium to at least 5 feet from the existing surface, the potential for significant soil collapse upon completion of grading is considered low.

2.2.2 Expansive Soil

Expansive soils contain significant amounts of clay particles that swell considerably when wetted and shrink when dried. Foundations constructed on these soils are subject to large uplifting forces caused by the swelling. Without proper measures taken, heaving and cracking of both building foundations and slabs-on-grade could result.

Based on results from representative sample collected at the site during exploration drilling, the onsite soils are anticipated to have a very low expansion potential.

PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 7 -

2.2.3 Sulfate Content

Water-soluble sulfates in soil can react adversely with concrete. However, concrete in contact with soil containing sulfate concentrations of less than

0.1 percent by weight is considered to have negligible sulfate exposure based on the American Concrete Institute (ACI) provisions, adopted by the 2019 CBC (CBC, 2019 and ACI, 2014).

A near-surface soil sample w as tested during this investigation for soluble sulfate content. The results of this test indicate a sulfate content less than

0.01 percent by weight, indicating negligible sulfate exposure (Exposure Class S0).

2.2.4 Resistivity, Chloride and pH

Soil corrosivity to ferrous metals can be estimated by the soil’s electrical resistivity, chloride content, and pH level. In general, soil having a minimum resistivity less than 1,000 ohm -cm is considered severely corrosive, while soil having a minimum resistivity of 1,000 to 2,000 is considered corrosive. Soil with a chloride content of 500 ppm or greater is considered corrosive to ferrous metals.

As a screening for potentially corrosive soil, a representative soil sample was tested during this investigation to estimate minimum resistivity, chloride content, and pH. This test indicated a minimum resistivity 1,100 ohm-cm, chloride content of 40 ppm, and pH of 7. 6. Based on these results, the onsite soil is considered corrosive to ferrous metals.

2.3 Groundwater

Groundwater was not encountered in our borings drilled onsite to a maximum explored depth of 51½ feet bgs. Historical data from groundwater elevation contour maps dating back to 1933 (CDWR, 1970) indicate groundwater levels in the area of the site on the order of approximately 775 above mean sea level, which correlates to a depth of about 82 feet bgs from the lowest elevation at the site. Recent groundwater data from the Western Municipal Water District (CDWR, 2022) indicated the shallowest groundwater historically measured from State Well No. 03S05W09E001S, located approximately 0.5 mile southwest from PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 8 -
the site, was 91 feet below ground surface (bgs) in 2012. Based on these, groundwater levels at this project site are expected to be deeper than 50 feet bgs.

2.4 Infiltration

Well permeameter i nfiltration testing was performed within borings IT-1 through IT-3 to evaluate infiltration characteristics of tested subsurface soils in those test zones. Out test zones were selected to target pockets of more granular layers with lower percent fines. Infiltration testing was conducted in general accordance with County of Riverside guidelines.

A well permeameter infiltration test is useful for field measurements of the infiltration rate of soils and is suited for testing when the design depth of the infiltration device is deeper than current existing grades, especially in areas where excavating a test pit is difficult, or where the depth of a test pit would be considerably deep. At this project site, testing consisted of advancing the borings at the locations indicated in the KMZ file provided by Psomas.

The three tests conducted at the subject site consisted of excavating a boring to the test depths of approximately 15, 20, and 48½ feet bgs. A layer of clean sand/gravel was placed in each boring bottom to support temporary perforated well casing pipe. In addition, No. 3 Monterey sand was poured around the outside of the well casing within each test zone to prevent the boring from caving/collapsing or eroding when water was added. A water hydrant with hose attached added water to the boring as water infiltrated into the soil. These tests were performed either by measuring the volume of water needed to maintain a constant water head in the boring or measuring the water level in the boring as it fell and the time that the water level t ook to decrease. The volume of water percolated during timed intervals was converted into an incremental infiltration rate, in inches per hour (in. /hr.). These tests were conducted based on the USBR 7300-89 test method.

Results of the infiltration testing are summarized below and are provided in Appendix A. The infiltration rates presented below are raw and a Factor of Safety has not been applied. Infiltration recommendations are included in Section 3.10 of this report.

PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 9 -
Table 1 – Minimum (Unfactored) Infiltration Rate
Boring Soil Type Approx. Test Zone Percent Fines
Unfactored
Infiltration Rate
(ft.), bgs (in./hr.)
IT-1 SM & ML 17 to 20 28 to 80 0.6
IT-2 SM 10 to 13 30 1.6
IT-3 SC,ML,SM 43 to 48 15 to 70 0.2

2.5 Faulting and Seismicity

Our review of available in- house literature indicates that there are no known active faults traversing or trending towards the site. The closest known active or potentially active fault is related to the San Jacinto f ault zone, located approximately 11.1 miles northeast of the site (see Figure 4, Regional Fault and Historical Seismicity Map).

The principal seismic hazard that could affect the site is ground shaking resulting from an earthquake occurring along several major active or potentially active faults in southern California. K nown regional faults that could produce the most significant ground shaking at the site include those associated with the San Jacinto and San Andreas fault zones as well as the Elsinore fault zone.

Site seismic parameters are included in Section 3.4 of this report.

2.6 Secondary Seismic Hazards

In general, secondary seismic hazards for sites in the region could include soil liquefaction, earthquake- induced settlement, lateral displacement, landslides , and earthquake-induced flooding. The potential for secondary seismic hazards at the site is discussed below.

2.6.1 Liquefaction Potential

Liquefaction is the loss of soil strength or stiffness due to a b uildup of pore-water pressure during severe ground shaking. Liquefaction is associated primarily with loose (low density), saturated, fine- to-medium grained, cohesionless soils. As the shaking action of an earthquake progresses, the soil grains are rearranged, and the soil densifies within a short period of time. Rapid densification of the soil results in a buildup of PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 10 -
pore-water pressure. When the pore- water pressure approaches the total overburden pressure, the soil reduces greatly in strength and temporarily behaves similarly to a fluid. Effects of liquefaction can include sand boils, settlement, and bearing capacity failures below structural foundations.

The site is mapped as being in a zone of low liquefaction susceptibility by County of Riverside’s Map My County database (RCIT, 2022). Due to the historical groundwater level at the site being deeper than 50 feet and the relatively dense nature of the underlying soils, liquefaction is not a concern for this site.

2.6.2 Seismically Induced Settlement

During a strong seismic event, seismically induced settlement can occur within loose to moderately dense, dry or saturated granular soil.

Settlement caused by ground shaking is often nonuniformly distributed, which can result in differential settlement.

We have performed analyses to estimate the potential for seismically induced settlement using the method of Tokimatsu and Seed (1987), and based on Martin and Lew ( 1999), considering the maximum considered earthquake (MCE) peak ground acceleration (PGA M). Design/historic high groundwater levels of 82 feet below ground surface were used in the analysis. Based on our analysis, a potential for approximately 1. 1 inches of seismic settlement is estimated at the site. Based on the implementation of our overexcavation recommendations presented later in this report, the estimated potential seismic settlement is reduced to approximately 0. 9 inch. Results of our seismic settlement analysis is presented in Appendix D.

If the potential differential settlement is estimated as half of the total seismic settlement over a horizontal distance of 30 feet, this would result in a maximum 0. 5 inch differential settlement in 30 feet, or angular distortion of 0. 0012L. This would be within the differential settlement threshold of 0.010L for “other multistory structures” of Risk Category II, as listed in Table 12.13- 3 of ASCE 7 -16. “Other” buildings are those not constructed with concrete or masonry wall systems (i.e. wood- or steel - framed). The structural engineer should determ ine Structure Type and PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 11 -
Risk Category and evaluate whether the differential settlement estimates described above are tolerable. A copy of ASCE 7- 16 Table 12.13- 3 is provided as follows for reference.

Table 12.13-3 Differential Settlement Threshold
Structure Type Risk Category
I or II III IV
Single-story structures with concrete or
masonry wall systems 0.0075L 0.005L 0.002L
Other single-story structures 0.015L 0.010L 0.002L
Multistory structures with concrete or
masonry wall systems 0.005L 0.003L 0.002L
Other multistory structures 0.010L 0.006L 0.002L

2.6.3 Slope Stability and Seismically Induced Landslides

The site and its immediate surroundings are generally level without significant slopes. This site is not considered susceptible to static slope instability or seismically induced landslides.

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3.0 CONCLUSIONS AND RECOMMENDATIONS

Based on this investigation, construction of the proposed development is feasible from a geotechnical standpoint. No severe geologic or soils related issues were identified that would preclude development of the site for the proposed improvements. The most significant geotechnical issues at the site are those related to the potential for strong seismic shaking and potentially compressible near -surface soils. Good planning and design of the project can limit the impact of these constraints. Remedial recommendations for these and other geotechnical issues are provided in the following sections.

Although not identified during this investigation, seepage pits, or other buried structures, trash pits, buried utilities, or items related to past site are likely present, though not encountered during our exploration. If such items are encountered during grading, they would require further evaluation and special consideration b ased on actual conditions encountered.

3.1 General Earthwork and Grading

All grading should be performed in accordance with the General Earthwork and Grading Specifications presented in Appendix E , unless specifically revised or amended below or by future recommendations based on final development plans.

3.1.1 Site Preparation

Prior to construction, the site should be cleared of vegetation, trash and debris, which should be disposed of offsite. Any underground obstructions should be removed, as should large tree s and their root systems.

Resulting cavities should be properly backfilled and compacted. Efforts should be made to locate existing utility lines. Those lines should be removed or rerouted if they interfere with the proposed construction, and the resulting cavities should be properly backfilled and compacted.

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3.1.2 Overexcavation and Recompaction

To reduce the potential for adverse differential settlement of the proposed improvements, the underlying subgrade soil should be prepared in such a manner that a uniform response to the applied loads is achieved.

Prior to overexcavation and recompaction of onsite native soils, any clean undocumented artificial fill should be removed and may be used as compacted fill for the project. Undocumented artificial fill has been estimated, based on observations of our borings, to reach depths of approximately 1 f oot to 2 ½ feet below the current ground surface.

Localized areas of deeper undocumented artificial fill may be encountered during grading.

In addition to the complete removals of undocumented artificial fill onsite and f or structures with shallow foundations, we recommend that onsite alluvial soils be overexcavated and recompacted to a minimum depth of 3 feet below the bottom of the proposed footings or 5 feet be low exist ing grade, whichever is deeper . Overexcavation and recompaction should extend a minimum horizontal distance of 5 feet from perimeter edges of the proposed footings (including columns connected to the buildings), or a distance equal to the depth of overexcavation below the footings , where feasible.

Local conditions may require that deeper overexcavation be performed; such areas should be evaluated by Leighton during grading.

Areas outside these overexcavation limits planned for asphalt or concret e pavement, flatwork, low retaining walls (3 feet or less; taller walls should be overexcavated per the recommendations for buildings ), and site walls, and areas to receive fill should be overexcavated to a minimum depth of 24 inches below the existing ground surface or 12 inches below the proposed subgrade (or bottom of footing), whichever is deeper. In addition, all undocumented artificial fill should be overexcavated.

After completion of the overexcavation, and prior to fill placement, the exposed surf aces should be scarified to a minimum depth of 6 inches, PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 14 -
moisture conditioned to or slightly above optimum moisture content, and recompacted to a minimum 90 percent relative compaction, relative to the ASTM D 1557 laboratory maximum density.

3.1.3 F ill Placement and Compaction

Onsite soil to be used for compacted structural fill should also be free of debris, organic material and oversized material (greater than 8 inches in largest dimension). Any soil to be placed as fill, whether onsite or imported material, should be reviewed and possibly tested by Leighton.

All fill soil should be placed in thin, loose lifts, moisture conditioned, as necessary, and compacted to a minimum 90 percent relative compaction.

The soils should be placed at or above optimum moisture content.

Relative compaction should be determined in accordance with ASTM Test Method D1557. The upper 8 inches of subgrade soils for pavement areas should be compacted to 95 percent relative compaction. Aggregate base for pavement should be compacted to a minimum of 95 percent relative compaction.

3.1.4 Import Fill Soil

Import soil to be placed as fill should be geotechnically accepted by Leighton. Preferably at least 3 working days prior to proposed import to the site, the contractor should provide Leighton pertinent information of the proposed import soil, such as location of the soil, whether stockpiled or native in place, and pertinent geotechnical reports if available. We recommend that a Leighton representative visit the proposed import site to observe the soil conditions and obtain representative soil samples.

Potential issues may include soil that is more expansive than onsite soil, soil that is too wet, soil that is too rocky or too dissimilar to onsite soils, oversize material, organics, debris, etc.

3.1.5 Shrinkage and Subsidence

The change in volume of excavated and recompacted soil varies according to soil type and location. This volume change is represented as PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 15 -
a percentage increase (bulking) or decrease (shrinkage) in volume of fill after removal and recompaction. Subsidence occurs as in- place soil (e.g., natural ground) is moisture- conditioned and densified to receive fill, such as in processing an overexcavation bottom. Subsidence is in addition to shrinkage due to recompaction of fill soil. Field and laboratory data used in our calculations included laboratory -measured maximum dry densities for soil types encountered at the subject site, the measured in- place densities of soils encountered and our experience. We preliminarily estimate the following earth volume changes will occur during grading:

Shrinkage Approximately 15 +/- 4 percent
Subsidence
(overexcavation bottom processing) Approximately 0.15 foot

The level of fill compaction, variations in the dry density of the existing soils and other factors influence the amount of volume change. Some adjustments to earthwork volume should be anticipated during grading of the site.

3.1.6 Rippability and Oversized Material

Generally, rock or rock fragments observed during our field investigation were less than 2 inches in dimension and generally located near the surface. Oversized rock (greater than 8 inches) encountered during earthwork activities should be placed in deeper fill areas or in non- structural areas (parking lots).

3.2 Shallow Foundation Recommendations

The proposed two- and three- story multifamily buildings can be supported on conventional spread or strip footing shallow foundation systems. Maximum column loading and wall loading is not available at the time of this report. We have anticipated that the proposed residential buildings will be wood- framed and lightly loaded. We assume a maximum column load of 50 kips and maximum wall load of 2.5 kips per lineal foot are generally applicable for the relatively light residential structural loads. Structural loading information should be provided to us when available for review.

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Overexcavation and recompaction of the footing subgrade soil should be performed as detailed in Section 3.1. The following recommendations are based on the onsite soil conditions and soils with a “very low” expansion potential.

3.2.1 Minimum Embedment and Width

Based on our preliminary investigation, footings should have a minimum embedment per code requirements, with a minimum width of 24 inches for isolated and continuous footings.

3.2.2 Allowable Bearing

An allowable bearing pressure of 2,000 pounds -per-square-foot (psf) may be used, based on the minimum embedment depth and width above. This allowable bearing value may be increased by 250 psf per foot increase in depth or width to a maximum allowable bearing pressure of 3,000 psf. If higher bearing pressures are required, this should be reviewed on a case- by-case basis and may include additional overexcavation and/or soil reinforcement. These allowable bearing pressures are for total dead load and sustained live loads. Footing reinforcement should be designed by the structural engineer.

3.2.3 Lateral Load Resistance

Soil resistance available to withstand lateral loads on a shallow foundation is a function of the frictional resistance along the base of the footing and the passive resistance that may develop as the face of the structure tends to move into the soil. The frictional resistance between the base of the foundation and the subgrade soil may be computed using a coefficient of friction of 0. 30. The passive resistance may be computed using an allowable equivalent fluid pressure of 240 pounds per cubic foot (pcf), assuming there is constant contact between the footing and undisturbed soil. The coefficient of frict ion and passive resistance may be combined without further reduction.

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3.2.4 Increase in Bearing and Friction - Short Duration Loads

The allowable bearing pressure and coefficient of friction values may be increased by one- third when considering loads of short duration, such as those imposed by wind and seismic forces.

3.3 Recommendations for Slabs-On-Grade

Concrete slabs -on-grade should be designed by the structural engineer in accordance with the current CBC for a soil with a very low expansion potential.

Where conventional light floor loading conditions exist, the following minimum recommendations should be used. More stringent requirements may be required by local agencies, the structural engineer, the architect, or the CBC. Laboratory testing should be conducted at finish grade to evaluate the expansion index of near-surface subgrade soils. In a ddition, slabs -on-grade should have the following minimum recommended components:

Subgrade Moisture Conditioning : The subgrade soil should be moisture conditioned to at least 2 percent above optimum moisture content to a minimum depth of 12 inches prior to placing steel or concrete.

Moisture Retarder: A minimum of 10-mil polyethelene moisture retarder (such as Stego Wrap) should be placed below slabs where moisture -sensitive floor coverings or equipment is planned. The structural engineer should specify pertinent concrete design parameters and moisture migration prevention measures, such as whether a sand blotter layer should be placed over the vapor retarder. G ravel or other protruding objects that could puncture the moisture retarder should be removed from the subgrade prior to placing the vapor retarder.

Concrete Thickness : Slabs -on-grade should be at least 4 inches thick.

Reinforcing steel should be designed by the structural engineer, but as a minimum should be No. 3 rebar placed at 18 inches on center, each direction, mid-depth in the slab.

Minor cracking of the concrete as it cures, due to drying and shrinkage is normal and should be expected. However, cracking is often aggravated by a high PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 18 -
water/cement ratio, high concrete temperature at the time of placement, small nominal aggregate size, and rapid moisture loss due to hot, dry, and/or windy weather conditions during placement and curing. Cracking due to temperature and moisture fluctuations can also be expected. Low slump concrete can reduce the potential for shrinkage cracking. Additionally, our experience indicates that reinforcement in slabs and foundations can generally reduce the potential f or concrete cracking. The structural engineer should consider these components in slab design and specifications.

Moisture retarders can reduce, but not eliminate moisture vapor rise from the underlying soils up through the slab. Floor covering manufacturers should be consulted for specific recommendations.

Leighton does not practice in the field of moisture vapor transmission evaluation, since this is not specifically a geotechnical issue. Therefore, we recommend that a qualified person, such as the f looring subcontractor and/or structural engineer, be consulted with to evaluate the general and specific moisture vapor transmission paths and any impact on the proposed construction. That person should provide recommendations for mitigation of potential adverse impact of moisture vapor transmission on various components of the structures as deemed appropriate.

3.4 Seismic Design Parameters

The site will experience strong ground shaking after the proposed project is developed resulting from an earthquake occurring along one or more of the major active or potentially active faults in southern California. Accordingly, the project should be designed in accordance with all applicable current codes and standards utilizing the appropriate seismic design parameters to reduce seismic risk as defined by California Geological Survey (CGS) Chapter 2 of Special Publication 117a (CGS, 2008). Through compliance with these regulatory requirements and the utilization of appropriate seismic design parameters selected by the design professionals, potential effects relating to seismic shaking can be reduced.

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The following parameters should be considered for design under the 2019 CBC:

Table 2 – Mapped 2019 CBC Seismic Parameters
2019 CBC Parameters (CBC or ASCE 7-16 reference) Value
2019 CBC
Site Latitude and Longitude (degrees): 33.9323, -117.4055 Site Class Definition (1613.2.2, ASCE 7-16 Ch 20) D ** Mapped Spectral Response Acceleration at 0.2s Period (1613.2.1), Ss 1.500 g Mapped Spectral Response Acceleration at 1s Period (1613.2.1), S1 0.572 g Short Period Site Coefficient at 0.2s Period (T1613.2.3(1)), Fa 1.000 g Long Period Site Coefficient at 1s Period (T1613.2.3(2)), Fv 1.728 g * Adjusted Spectral Response Acceleration at 0.2s Period (1613.2.3), SMS 1.500 g Adjusted Spectral Response Acceleration at 1s Period (1613.2.3), SM1 0.988 g * Design Spectral Response Acceleration at 0.2s Period (1613.2.4), SDS 1.000 g Design Spectral Response Acceleration at 1s Period (1613.2.4), SD1 0.659 g * Mapped MCEG peak ground acceleration (11.8.3.2, Fig 22-9 to 13), PGA 0.500 g Site Coefficient for Mapped MCEG PGA (11.8.3.2), FPGA 1.100 Site-Modified Peak Ground Acceleration (1803.5.12; 11.8.3.2), PGAM 0.550 g * Per Table 11.4-2 of Supplement 1 of ASCE 7-16, this value of Fv may only be used to calculate Ts [that note is not included in Table 1613A.2.3(2)]; note that SD1 and SM1 are functions of Fv. In addition, per Exception 2 of 11.4.8 of ASCE 7-16, special equations for Cs are required. This is in lieu of a site-specific ground motion hazard analysis per ASCE 7-16 Chapter 21.2. ** Site Class D, and all of the resulting parameters in this table, may only be used for structures without seismic isolation or seismic damping systems.

Based on the 2019 CBC Table 1613.2.3(2) footnote c., F v should be determined in accordance with Section 11.4.8 of ASCE 7- 16, since the mapped spectral response acceleration at 1 second is greater than 0.2g for Site Class D; in accordance with Section 11.4.8 of ASCE 7-16, a site-specific seismic analysis is required. However, the values provided in the table above may be utilized if design is performed in accordance with Exception (2) in Section 11.4.8 of ASCE 7-16, with special requirements for the seismic response coefficient (C s), and F v
is only used for calculation of T s. This exception does not apply (and the values in the table above would not be applicable) for proposed structures with seismic isolation or seismic damping systems. The project structural engineer should PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 20 -
review the seismic parameters. A site- specific seismic ground motion analysis can be performed upon request.

Based on ASCE 7 -16 Equation 11.8- 1, the F PGA is 1.1, the PGA is 0.500g and the PGAM is 0.550g. As an added check, PGA and haz ard deaggregation were also estimated using the United States Geological Survey’s (USGS) 2008 Interactive Deaggregations utility. The results of this analysis indicate that the predominant mo dal earthquake has a PGA of 0.75g wit h a magnitude of approximately 8.1 (MW) at a distance on the order of 17.9 kilometers for the Maximum Considered Earthquake (2% probability of exceedance in 50 y ears); 2/3 of this value is 0.42g. Deaggregation results are included in Appendix C.

3.5 Retaining Walls

We are not aware that retaining walls will be constructed at the project site. The following retaining wall recommendations are included for design consideration of walls a height less than 6 feet. Taller walls should be reviewed on a case- by- case basis. We recommend that retaining walls be backfilled with low expansive soil and constructed with a back drain in accordance with the recommendations provided on Figure 5 (rear of text). Based on these recommendations, the following parameters may be used for the design of conventional retaining walls:

Static Equivalent Fluid Pressure (pcf)
Condition Level Backfill
Active 40 pcf
At-Rest 60 pcf
Passive 240 pcf (allowable)
(Maximum of 3,000 psf)

The above values do not contain an appreciable factor of safety unless noted, so the structural engineer should apply the applicable factors of safety and/or load factors during design, as specified by the California Building Code.

Cantilever walls that are designed to yield at least 0.001H, where H is equal to the wall height, may be designed using the active condition. Rigid walls and walls braced at the top should be designed using the at-rest condition.

Passive pressure is used to compute soil resistance to lateral structural PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 21 -
movement. In addition, for sliding resistance, a frictional resistance coefficient of

0.30 may be used at the concrete and soil interface. The lateral passive resistance should be taken into account only if it is ensured that the soil providing passive resistance, embedded against the foundation elements, will remain intact with time.

In addition to the above lateral forces due to retained earth, surcharge due to improvements, such as an adjacent structure or traffic loading, should be considered in the design of the retaining wall. Loads applied within a 1:1 projection from the surcharging structure on the stem of the wall should be considered in the design.

We recommend that the wall designs for walls 6 feet tall or taller be checked seismically using an additive seismic Equivalent Fluid Pressure (EFP) of 20 pcf of level backfill, which is added to the equivalent fluid pressure.

A soil unit weight of 120 pcf may be assumed for calculating the actual weight of the soil over the wall footing.

Retaining wall footings should have a minimum width of 24 inches and a minimum embedment of 18 inches below the lowest adjacent grade. An allowable bearing capacity of 2,000 pcf may be used for retaining wall footing design, based on the minimum footing width and depth.

3.6 Pavement Design

Based on the design procedures outlined in the 2017 Caltrans Highway Design Manual and using a design R -value of 35 based on near surface soils laboratory testing and our experience with nearby sites, flexible pavement sections may consist of the following for the traffic ind ex indicated. Final pavement design should be based on the Traffic Index determined by the project civil engineer and R-value testing provided near the end of grading.

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Traffic Index Asphaltic Concrete (AC)
Thickness (inches)
Class 2 Aggregate Base
Thickness (inches)
5 or less (auto access) 3.0 4.5
7 (truck access and fire lanes) 4.0 8.5

If asphalt pavement is to be constructed prior to construction, the full pavement thickness should be placed to support heavy construction traffic.

In areas where rigid concrete pavement is planned with auto and light truck access, we recommend 5 inches of Portland Cement Concrete (PCC) over 4 inches of aggregate base placed on prepared subgrade soil. For heavy truck access, we recommend a minimum of 6 inches of PCC over 6 inches of aggregate base. The PCC should have a 28- day compressive strength of 4,000 psi. Reinforcement should be specified by the structural engineer. The PCC pavement sections should be provided with crack -control joints spaced no more than 8 feet on center each way. If sawcuts are used, they should have a minimum depth of ¼ of the slab thickness and made within 24 hours of concrete placement. We recommend that sections be as nearly square as possible.

PCC sidewalks should be at least 4 inches thick over prepared subgrade soil, with construction joints no more than 8 feet on center each way, with sections as nearly square as possible. Use of reinforcing will help reduce severity of cracking.

For concrete trash aprons, ADA stalls and ADA cross -walks, we recommend that a minimum 5 inches of concrete over prepared subgrade soil.

All pavement construction should be performed in accordance with the Standard Specifications for Public Works Construction. Field observations and periodic testing, as needed during placement of the base course materials, should be undertaken to ensure that the requirements of the standard specifications are fulfilled. Prior to placement of aggregate base, the subgrade soil should be processed to a minimum depth of 6 inches, moisture- conditioned, as necessary, and recompacted to a minimum of 95 percent relative compaction. Aggregate base should be moisture conditioned, as necessary, and compacted to a minimum of 95 percent relative compaction.

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3.7 Temporary Excavations

All temporary excavations, including utility trenches, retaining wall excavations and other excavations should be performed in accordance with project plans, specifications and all OSHA requirements.

No surcharge loads should be permitted within a horizontal distance equal to the height of cut or 5 feet, whichever is greater from the top of the slope, unless the cut is shored appropriately. Excavations that extend below an imaginary plane inclined at 45 degrees below the edge of any adjacent existing site foundation should be properly shored to maintain support of the adjacent structures.

Cantilever shoring should be designed based on an active equivalent fluid pressure of 40 pcf. If excavations are braced at the top and at specific design intervals, the active pressure may then be approximated by a rectangular soil pressure distribution with the pressure per foot of width equal to 26 H, where H is equal to the depth of the excavation being shored.

During construction, the soil conditions should be regularly evaluated to verify that conditions are as anticipated. The contractor should be responsible for providing the "competent person" required by OSHA, standards to evaluate soil conditions. Close coordination between the competent person and the geotechnical engineer should be maintained to facilitate construction while providing safe excavations.

3.8 Trench Backfill

Utility-type trenches onsite can be backfilled with the onsite material, provided it is free of debris, organic and oversized material. Prior to backfilling the trench, pipes should be bedded and shaded in a granular material that has a sand equivalent of 30 or greater and will allow water to readily permeate. Gravel or rock should not be used for trench backfill without written approval by Leighton. If gravel or open- graded rock is approved and used as bedding or shading, it should be wrapped in Mirafi 140N filter fabric, or equivalent, to prevent surrounding soil from washing into the pore spaces in the gap gr aded rock.

Shading should extend at least 12 inches above the top of the pipe. The bedding/shading materials should be densified in- place by mechanical means, or in accordance with Greenbook specifications.

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Subsequent to pipe bedding and shading, backfi ll soils should be placed in loose layers, moisture conditioned, as necessary, and mechanically compacted using a minimum standard of 90 percent relative compaction (ASTMS D1557). The thickness of layers should be based on the compaction equipment used in accordance with the Standard Specifications for Public Works Construction (Greenbook). The upper 6 inches in pavement areas should be compacted to 95 percent compaction.

3.9 Surface Drainage

Inadequate control of runoff water and/or poorly controlled irrigation can cause the onsite soils to expand and/or shrink, producing heaving and/or settlement of foundations, flatwork, walls, and other improvements. Maintaining adequate surface drainage, proper disposal of runoff water, and control of irrigation should help reduce the potential for future soil moisture problems.

Positive surface drainage should be designed to be directed away from foundations and toward approved drainage devices, such as gutters, paved drainage swales, or watertight area drains and collector pipes.

Surface drainage should be provided to prevent ponding of water adjacent to the structures. In general, the area around the buildings should slope away from the building. We recommend that unpaved landscaped areas adjacent to the buildings be avoided. Roof runoff should be carried to suitable drainage outlets by watertight drain pipes or over paved areas.

3.10 Infiltration Recommendations

Although variability was encountered in the soils throughout the site, with soils below 20 feet containing large amounts of variation with clays, silts, and both silty and clayey sands with high amounts of fines (silt and clay), which yielded low infiltration rates during our testing, a mostly continuous silty sand layer with lower percent fines was encountered from approximately 10 to 15 feet bgs at the infiltration test locations. For the underlying alluvial soils that are granular with a low fines content, we recommend an unfactored (small -scale) infiltration rate of

0.7 inch per hour (reduced due to presence of finer -grained soils below) , for depths of at least 10 feet below current grade on the southwestern half of the site. Dry well systems may be feasible to infiltrate into the deeper granular layers PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 25 -
in some areas of the site. We recommend that infiltration systems extend a minimum of 10 feet below current grades.

Based on our testing, infiltration appears to b e feasible in the southern region of the project site, but dependent upon location and depth of infiltration due to the variances in soil composition encountered at the site and the results of percolation testing. Additional testing to confirm the location, depth of invert and type of device should be anticipated if locations differ from areas and depths tested.

We recommend that a correction factor/safety factor be applied to the infiltration rate in conformance with Riverside County guidelines, since monitoring of actual facility performance has shown that actual infiltration rates are lower than measured in small -scale tests. Infiltration basins are subject to siltation, which can result in reduced infiltration rates. This small -scale infiltration rate should be divided by a design factor of at least 3 for buried chambers and dry wells, and at least 4 for open basins; although the design/safety factor may be higher based on project-specific aspects. It should be noted that during periods of prolonged precipitation, underlying soils tend to become saturated to greater depths/extent.

Therefore, infiltration rates tend to decrease with prolonged rainfall.

Some design considerations are presented in the following paragraphs:

 Adjacent Structure Impact : As infiltrating water can seep within soil strata partially horizontally, it is important to consider impact that infiltration facilities can play on nearby subterranean structures, such as basement walls or open excavations, whether onsite or o ffsite, and whether existing or planned. Any such nearby features should be identified and evaluated as to whether infiltrating water can impact these facilities. Infiltration facilities should not be constructed adjacent to or under buildings. Setbacks should be discussed with Leighton during the planning process, but a building setback of at least 15 feet horizontally is initially suggested.

 Dry Well Locations and Depths: Further testing may be required depending on final design of infiltration dry wells. Infiltration rates are anticipated to vary based on location and depth. Infiltration concepts should be discussed with Leighton as infiltration plans are being developed. We should review all PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 26 -
infiltration plans, including locations and depths of proposed facilities. Further testing may be required depending on infiltration facilities design details, particularly considering type, depth and location.

 Siltation and Soil Changes: These infiltration rates are for a clean, un- silted infiltration surface in native, sandy alluvial soil. These values may be reduced over time as silting of the basin or chamber occurs. Furthermore, if the basin or chamber bottom is allowed to be compacted by heavy equipment, this value is expected to be reduced. Infiltration of water through soil is highly dependent on such factors as grain size distribution of soil particles, gradation (uniform versus well graded), particle shape, fines content and density. Small changes in soil conditions, including density, can cause large differences in observed infiltration rates. Infiltration is not suitable in compacted fill. For open basins and swales, vegetation within the basin bottoms and sides is expected to help reduce erosion and help maintain infiltration rates.

 De-silting Weir/Facilities: Periodic flow of water carrying sediments into the basin or chamber, plus deposition of fine wind- blown sediments and sediments from erosion of basin side walls, will eventually cause the basin bottom or chamber to accumulate a layer of silt, which has the potential to significantly reducing the overall infiltration rate of the basin or chamber.

Therefore, we recommend that significant amounts of silt/sediment not be allowed to flow into the facility within stormwater, especially duri ng construction of the project and prior to achieving a mature landscape onsite.

We recommend that an easily maintained, robust silt/sediment removal system be installed to pretreat storm water before it enters the infiltration facility. Infiltration fac ilities should be constructed with spillways or other appropriate means that would prevent overfilling that could damage the facility or adjacent improvements.

 Drainage/Infiltration Time Cycle : In general, the rate of infiltration reduces as the head of water in the infiltration facility reduces, and it also reduces with prolonged periods of infiltration. As such, water typically infiltrates much faster near the beginning of and/or immediately after storm events than at times well after a storm when the water level in the facility has receded, since the infiltration rate is then slower due to both lower head and longer overall duration of infiltration. In open basins with compacted or silty bottoms, this PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 27 -
could be problematic, in that even if the basin had already infiltrated significant amounts of storm water, the lower several inches or feet of water could remain in the basin for an extended period of time, creating prolonged open-water safety concern (such as potential for mosquitos and waterborne diseases, algae odor, etc.). In a buried/cover infiltration chamber, these conditions would be of less concern.

 Maintenance: Infiltration facilities should be routinely monitored, especially before and during the rainy season, and corrective measures should be implemented if and as needed. Things to check for include removal of trash or dumping, proper infiltration, absence of accumulated silt, and that de- silting filters/features are clean and functioning. Pretreatment desilting features should be cleaned and maintained as recommended by the manufacturer or designer. Even with measures to prevent silt from flowing into the infiltration facility, accumulated silt may need to be removed.

3.11 Sulfate Attack and Corrosion Protection

Based on the results of laboratory testing, concrete structures in contact with the onsite soil will have negligible exposure to water -soluble sulfates in the soil (Exposure Class S0) . Typ e II cement may be used for concrete construction.

The concrete should be designed in accordance with Table 4.3.1 of the American Concrete Institute ACI 318-14 provisions (ACI, 2014).

Based on our laboratory testing, the onsite soil is considered corrosive to ferrous metals. Corrosion protection of underground metallic utilities should be provided.

Corrosion information presented in this report should be provided to your underground utility contractors.

3.12 Additional Geotechnical Services

The preliminary geotechnical recommendations presented in this report are based on subsurface conditions as interpreted from limited subsurface explorations and limited laboratory testing. Our preliminary geotechnical recommendations provided in this report are based on information available at the time the report was prepared and may change as plans are developed .

Additional geotechnical investigation and analysis may be required based on final improvement plans. Leighton should review the site and grading plans when PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 28 -
available and comment further on the geotechnical aspects of the project.

Geotechnical observat ion and testing should be conducted during excavation and all phases of grading operations. Our conclusions and preliminary recommendations should be reviewed and verified by Leighton during construction and revised accordingly if geotechnical conditions encountered vary from our preliminary findings and interpretations.

Geotechnical observation and testing should be provided:

• After completion of site clearing.
• During overexcavation of compressible soil.
• During compaction of all fill materials.
• After excavation of all footings and prior to placement of concrete. • During utility trench backfilling and compaction.
• During pavement subgrade and base preparation.
• When any unusual conditions are encountered.

PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Proposed Madison Flats Multifamily Residential Development Riverside, CA 13693.001 - 29 -

4.0 LIMITATIONS

This report was based in part on data obtained from a limited number of observations, site visits, soil excavations, samples, and tests. Such information is, by necessity, incomplete. The nature of many sites is such that differing soil or geologic conditions can be present within small distances and under varying climatic conditions. Changes in subsurface conditions can and do occur over time. Therefore, our findings, conclusions, and recommendations presented in this report are based on the assumption that Leighton and Associates, Inc. will provide geotechnical observation and testing during construction.

This report was prepared for the sole use of the Gilbane Development Company for application to the design of the proposed residential development in accordance with generally accepted geotechnical engineering practices at this time in California.

See the GBA insert on the following page for important information about this geotechnical engineering report.

PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices ?ÆE
?ÆE
³
0 2,000 4,000
Feet
Scale:1 " = 2,000 '
Project: 13693.001 Eng/Geol: JDH/SGO
Map Saved as J:\Drafting\13693\001\Maps\13693.001_F01_SLM_2022-11-09.mxd on 11/9/2022 1:16:03 PM Author: KVM (btran) Date: November 2022

SITE LOCATION MAP
Proposed Multi-Family Residential Development
Southwest of Madison Street and Railroad Avenue
Riverside, California
Approximate
Site Location
FIGURE 1
Reference: Copyright:© 2013 National
Geographic Society, i-cubed
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Map Saved as J:\Drafting\13693\001\Maps\13693.001_F02_BLM_2022-11-09.mxd on 11/9/2022 1:10:33 PM Author: KVM (btran)

BORING LOCATION MAP
Proposed Multi-Family Residential Development
Southwest of Madison Street and Railroad Avenue
Riverside, California
LEGEND
&< Approximate location of
boring
&( Approximate location of
infiltration test
Approximate Site
Boundary
³
01 5 0 3 0 0
Feet
Scale:1 " = 150 '
Project: 13693.001 Eng/Geol: JDH/SGO
Date: November 2022
LB-7
FIGURE 2
Reference: © 2022 Microsoft Corporation © 2022
Maxar ©CNES (2022) Distribution Airbus DS © 2022
Tom Tom
IT-3
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Qof
gr
Qyf
Qvof
Scale:

Reference: Southern California USGS Geology in GIS Format served by California Geological Survey, 2018.
1 " = 2,000 '
Project: 13693.001 Eng/Geol: JDH/SGO
Map Saved as J:\Drafting\13693\001\Maps\13693.001_F03_RGM_2022-11-09.mxd on 11/9/2022 1:29:08 PM Author: KVM (btran) Date: November 2022

REGIONAL GEOLOGY MAP
Approximate
Site Location
Proposed Multi-Family Residential Development
Southwest of Madison Street and Railroad Avenue
Riverside, California
FIGURE 3
³
0 2,000 4,000
Feet
LEGEND
Qyf, Young Alluvial Fan Deposits
! Qyw, Young Alluvial Wash Deposits
Qof, Old Alluvial Fan Deposits
Qvof, Very Old Alluvial Fan Deposits
gr, Granitic and other intrusive crystalline
rocks of all ages
pKm, Cretaceous and Pre-Cretaceous
metamorphic formations of sedimentary and
volcanic origin
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices ³
0 5 10
Miles
Scale: 1 " = 5 miles
Project: 13693.001 Eng/Geol: JDH/SGO
Map Saved as J:\Drafting\13693\001\Maps\13693.001_F04_RFHSM_2022-11-09.mxd on 11/9/2022 1:18:06 PM Author: KVM (btran) Date: November 2022

REGIONAL FAULTS AND

HISTORICAL SEISMICITY MAP
Proposed Multi-Family Residential Development
Southwest of Madison Street and Railroad Avenue
Riverside, California
Approximate
Site Location
Basemap Reference: © 2022 Microsoft Corporation
Earthstar Geographics SIO © 2022 TomTom
Seismicity Data Reference: maps.conservation.ca.gov
L E G E N D
F a u l t a c t i v i t y
R e c e n c y o f M o v e me n t
Holocene (<11,700 years)
Late Quaternary (last 700,000 years)
Quaternary (<1.6M years)
H i s t o r i c a l E a r t h q u a k e s ( "e M 3 . 5 ) ! 3.5 - 3.99
! 4.0 - 4.99
! 5.0 - 5.99
! 6.0 - 6.99
F I G U R E 4
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices

APPENDIX A

REFERENCES
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices 13693.001
A-1

APPENDIX A

References

American Concrete Institute (ACI), 2014, Building Code Requirements for Structural Concrete (ACI 318-14) and Commentary (ACI 318R-14), an ACI Standard, 2014.

California Building Standards Commission, 2019, 2019 California Building Code, California Code of Regulations, Title 24, Part 2, Volume 2 of 2, Based on 2018 International Building Code, Effective January 1, 2020.

California Department of Water Resources (CDWR), 1970, Meeting Water Demands in the Chino-Riverside Area, Bulletin No. 104-3, dated September 1970 _____, 2022a, Sustainable Groundwater Management Act Data Viewer Tool, Website:
https://sgma.water.ca.gov/webgis/?appid=SGMADataViewer#gwlevels; accessed October 28, 2022.

California Geologic Survey, 2008, Guidelines for Evaluating and Mitigating Seismic Hazards in California, Special Publication 117A, Revised and Re -Adopted on September 11, 2008, Laguna Beach, California.

Dibblee, T.W., Minch, J.A., 2003, Geologic Map of the Riverside East/ South ½ of San Bernardino South Quadrangles, San Bernardino and Riverside County, California, Dibblee Foundation Map DF-109, scale 1:24,000.

Public Works Standard, Inc., 2018, Greenbook, Standard Specifications for Public Works Construction: BNI Building News, Anaheim, California Office of Statewide Health Planning and Development (OSHPD) and Structural Engineers Association of California (SEAOC), 2021, Seismic Design Maps website: https://seismicmaps.org, accessed November 7, 2022.

Morton, D.M., Cox, B.F., Dawson, M., O’Brien, T., 2002, Geologic Map of the Riverside East 7.5’Quadrangle, Riverside County, California, U.S. Geological Survey Open-File Report OF-2001-452, scale 1:24,000.

PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices 13693.001
A-2
Nationwide Historical Environmental Title Research (NETR) 2022, Historical Aerial website: https://www.historicaerials.com/, accessed on November 28, 2022 Riverside Cou nty Information Technology (RCIT), 2022 Map My County website:
https://gis1.countyofriverside.us , accessed November 28, 2022.

United States Geologic Survey (USGS), 2021, Earthquake Hazards Program, Unified Hazard Tool, website: https://earthquake.usgs.gov/hazards/interactive, accessed October 31, 2022.

Youd, T.L., Idriss, I.M., Andrus, R.D., Arango, I., Castro, G., Christian, J.T., Dobry, R., Finn, L., Harder, L.F., Hynes, M.E., Ishihara, K., Koester, J.P., Liao, S.C., Marcuson, W.F. III, Martin, G.R., Mitchell, J.K., Moriwaki, Y., Power, M.S., Robertson, P.K., Seed, R.B., Stokoe, K.H. II, 2001, “Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils”, Journal of Geotechnical and Geoenvironmental Engineering, Vol. 127, No. 10, October 2001.

PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices

APPENDIX B
GEOTE

CHNICAL EXPLORATION LOGS
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices SM
SM
SM
SM
SM
SP
CL
SM
ML
115
114
117
115
127
5 6
7 10
8 B-1
R-1
R-2
R-3
R-4
S-1
R-5
S-2
-200
7 6
6 4
6 7
7 10
11 7
8 13
4 5
6 12
18 24
4 3
4 Artificial Fill (Afu):
@Surface: SILTY SAND WITH GRAVEL (SM), brown, dry, fine to coarse sand, 20% fines, 10% gravel (field estimate)
Old Alluvial Fan Deposits (Qof):
@2.5': SILTY SAND (SM), loose, brown, dry, fine to medium sand, 45% fines (field estimate)
@5': SILTY SAND (SM), loose, brown, dry, fine to medium sand, 35% fines (field estimate)
@7.5': SILTY SAND (SM), medium dense, brown, dry, fine to coarse sand, 35% fines (field estimate)
@10': SILTY SAND (SM), medium dense, brown, dry, fine to coarse sand, 35% fines (field estimate)
@15': POORLY GRADED SAND (SP), medium dense, light brown, slightly moist, fine to coarse sand, 5% fines (lab)
@20': SANDY LEAN CLAY (CL), very stiff, brown, slightly moist, 70% medium plasticity fines (field estimate)
@21.25': SILTY SAND (SM), medium dense, brown, slightly moist, medium to coarse sand, 15% fines (field estimate)
@25': SANDY SILT (ML), medium stiff, brown, slightly moist, fine to medium sand, 70% low plasticity fines (field estimate) Project No.

Ground Elevation
Depth
Blows
Elevation
Per 6 Inches

Attitudes
SAMPLE TYPES:
2R Drilling
Content, %
Logged By
Date Drilled
860
855
850
845
840
835
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * * AA
Feet
S
(U.S.C.S.)
Log
Type of Tests
Graphic
pcf
861'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
AA
Hollow Stem Auger - Autohammer
0 5
10 15
20 25
30 Soil Class.
11-3-22

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Location See Figure 2 - Boring Location Map
Gilbane Development - Madison Flats
13693.001
Drilling Method
8"
Feet
Hole Diameter
Moisture
Dry Density
N
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC
Sample No.

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE

STRENGTH
GEOTECHNICAL BORING LOG LB-1
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices CL
CL
ML
SC
SC
R-6
S-3
R-7
S-4
R-8
11 16
22 8
12 17
28 50/5"
27 50/6"
@30': LEAN CLAY WITH SAND (CL), very stiff, brown, slightly moist, 80% medium plasticity fines (field estimate)
-Soil stuck on auger, difficult to drill
@35': LEAN CLAY WITH SAND (CL), brown, slightly moist, slow dilatency, 80% medium plasticity fines (field estimate) @40': SANDY SILT (ML), very stiff, brown, slightly moist, fine to medium sand, 70% low plasticity fines (field estimate)
@45': CLAYEY SAND (SC), very dense, orangish brown, slightly moist, medium to coarse sand, 40% fines (field estimate) @50': CLAYEY SAND (SC), very dense, orangish brown, slightly moist, medium to coarse sand, 20% fines (field estimate) TOTAL DEPTH = 51 FEET

NO GROUNDWATER ENCOUNTERED

BACKFILLED TO SURFACE WITH SOIL CUTTINGS
Project No.

Ground Elevation
Depth
Blows
Elevation
Per 6 Inches

Attitudes
SAMPLE TYPES:
2R Drilling
Content, %
Logged By
Date Drilled
830
825
820
815
810
805
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * * AA
Feet
S
(U.S.C.S.)
Log
Type of Tests
Graphic
pcf
861'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
AA
Hollow Stem Auger - Autohammer
30 35
40 45
50 55
60 Soil Class.
11-3-22

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Location See Figure 2 - Boring Location Map
Gilbane Development - Madison Flats
13693.001
Drilling Method
8"
Feet
Hole Diameter
Moisture
Dry Density
N
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC
Sample No.

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE

STRENGTH
GEOTECHNICAL BORING LOG LB-1
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices SM
SM
SC
SC
SM
SM
SM
113
116
5 8
B-1
R-1
R-2
R-3
R-4
S-1
R-5
AL, -200
4 7
10 4
6 7
5 7
9 7
11 15
3 6
5 5
9 17
Artificial Fill (Afu):
@Surface: SILTY SAND WITH GRAVEL (SM), brown, dry, fine to coarse sand, 20% fines, 10% gravel (field estimate)
Old Alluvial Fan Deposits (Qof):
@2.5': SILTY SAND (SM), medium dense, brown, slihgtly moist, fine to medium sand, 45% fines (field estimate)
@5': CLAYEY SAND (SC), loose, brown, slightly moist, low toughness, 41% fines (lab)
@7.5': CLAYEY SAND (SC), medium dense, brown, slightly moist, low toughness, 45% low plasticity fines (field estimate) @10': SILTY SAND (SM), medium dense, brown, slightly moist, fine sand, 45% fines (field estimate)
@15': SILTY SAND (SM), medium dense, brown, slightly moist, fine sand, 40% fines (field estimate)
@20': SILTY SAND (SM), medium dense, brown, slightly moist, fine sand, 30% fines (field estimate)
TOTAL DEPTH = 21.5 FEET

NO GROUNDWATER ENCOUNTERED

BACKFILLED TO SURFACE WITH SOIL CUTTINGS
Project No.

Ground Elevation
Depth
Blows
Elevation
Per 6 Inches

Attitudes
SAMPLE TYPES:
2R Drilling
Content, %
Logged By
Date Drilled
860
855
850
845
840
835
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * * AA
Feet
S
(U.S.C.S.)
Log
Type of Tests
Graphic
pcf
862'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
AA
Hollow Stem Auger - Autohammer
0 5
10 15
20 25
30 Soil Class.
11-3-22

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Location See Figure 2 - Boring Location Map
Gilbane Development - Madison Flats
13693.001
Drilling Method
8"
Feet
Hole Diameter
Moisture
Dry Density
N
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC
Sample No.

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE

STRENGTH
GEOTECHNICAL BORING LOG LB-2
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices SM
SM
ML
SC
ML
SP
SC
CL
117
111
122
115
116
3 10
6 13
7 B-1
R-1
R-2
R-3
R-4
S-1
R-5
S-2

MD, SA,
CR
CO
-200, AL
-200
6 7
8 3
5 10
5 9
10 4
9 12
3 7
6 8
14 18
5 9
10 Artificial Fill (Afu):
@Surface: SILTY SAND WITH GRAVEL (SM), brown, slightly
moist, fine to coarse sand, 20% fines, 30% gravel (field estimate)
Old Alluvial Fan Deposits (Qof):
@2.5': SILTY SAND (SM), loose, brown, dry, fine to coarse sand, 40% fines (field estimate)
@5': LEAN CLAY WITH SAND (CL), stiff, brown, slightly moist, 85% medium plasticity fines (field estimate)
@7.5': CLAYEY SAND (SC), medium dense, brown, slightly moist, 42% fines (lab)
@10': SANDY SILT (ML), stiff, brown, slightly moist, 75% medium plasticity fines (field estimate)
@15': POORLY GRADED SAND (SP), medium dense, brown,
slightly moist, fine to coarse sand, 5% fines (lab)
@20': CLAYEY SAND (SC), medium dense, brown, slightly moist, 45% medium plasticity fines (field estimate)
@25': LEAN CLAY (CL), very stiff, brown, slightly moist, 90% medium plasticity fines (field estimate)
Project No.

Ground Elevation
Depth
Blows
Elevation
Per 6 Inches

Attitudes
SAMPLE TYPES:
2R Drilling
Content, %
Logged By
Date Drilled
860
855
850
845
840
835
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * * AA
Feet
S
(U.S.C.S.)
Log
Type of Tests
Graphic
pcf
861'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
AA
Hollow Stem Auger - Autohammer
0 5
10 15
20 25
30 Soil Class.
11-3-22

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Location See Figure 2 - Boring Location Map
Gilbane Development - Madison Flats
13693.001
Drilling Method
8"
Feet
Hole Diameter
Moisture
Dry Density
N
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC
Sample No.

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE

STRENGTH
GEOTECHNICAL BORING LOG LB-3
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices CL
ML
SC
SM
ML
R-6
S-3
R-7
S-4
R-8
8 13
23 8
9 13
26 50/5"
10 12
17 13
28 32
@30': LEAN CLAY (CL), very stiff, brown, slightly moist, 90% medium plasticity fines (field estimate)
@35': SILT WITH SAND (ML), very stiff, brown, slightly moist, 80% low plasticity fines (field estimate)
@40': CLAYEY SAND (SC), very dense, brown and white, slightly moist, fine to coarse sand, cemented, 30% fines (field estimate) @45': SILTY SAND (SM), medium dense, brown, slightly moist, fine to medium sand, 35% fines (field estimate)
@50': SANDY SILT (ML), hard, brown, slightly moist, fine to medium sand, 60% low plasticity fines (field estimate)
TOTAL DEPTH = 51.5 FEET

NO GROUNDWATER ENCOUNTERED

BACKFILLED TO SURFACE WITH SOIL CUTTINGS
Project No.

Ground Elevation
Depth
Blows
Elevation
Per 6 Inches

Attitudes
SAMPLE TYPES:
2R Drilling
Content, %
Logged By
Date Drilled
830
825
820
815
810
805
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * * AA
Feet
S
(U.S.C.S.)
Log
Type of Tests
Graphic
pcf
861'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
AA
Hollow Stem Auger - Autohammer
30 35
40 45
50 55
60 Soil Class.
11-3-22

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Location See Figure 2 - Boring Location Map
Gilbane Development - Madison Flats
13693.001
Drilling Method
8"
Feet
Hole Diameter
Moisture
Dry Density
N
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC
Sample No.

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE

STRENGTH
GEOTECHNICAL BORING LOG LB-3
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices ML
SM
SM
SM
CL
SC
120
118
9 9
R-1
R-2
R-3
R-4
S-1
R-5
5 4
5 6
8 9
12 15
17 9
8 11
6 7
9 13
15 19
Artificial Fill (Afu):
@Surface: SILTY SAND WITH GRAVEL (SM), brown, slightly
moist, fine to coarse sand, 15% fines, 10% gravel (field estimate)
Old Alluvial Fan Deposits (Qof):
@2.5': SANDY SILT (ML), medium stiff, brown, slightly moist, fine sand, 65% low plasticity fines (field estimate)
@5': SILTY SAND (SM), medium dense, brown, slightly moist, medium to coarse sand, 30% fines (field estimate)
@7.5': SILTY SAND (SM), medium dense, brown, slightly moist, medium to coarse sand, 30-45% fines (field estimate)
@10': SILTY SAND (SM), medium dense, brown, slightly moist, fine sand, 30% fines (field estimate)
@15': CLAY with SAND (CL), stiff, brown, slightly moist, 80% medium plasticity fines (field estimate)
@20': CLAYEY SAND (SC), medium dense, brown, slightly moist, fine to coarse sand, 45% medium plasticity fines (field estimate) TOTAL DEPTH = 21.5 FEET

NO GROUNDWATER ENCOUNTERED

BACKFILLED TO SURFACE WITH SOIL CUTTINGS
Project No.

Ground Elevation
Depth
Blows
Elevation
Per 6 Inches

Attitudes
SAMPLE TYPES:
2R Drilling
Content, %
Logged By
Date Drilled
855
850
845
840
835
830
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * * AA
Feet
S
(U.S.C.S.)
Log
Type of Tests
Graphic
pcf
857'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
AA
Hollow Stem Auger - Autohammer
0 5
10 15
20 25
30 Soil Class.
11-3-22

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Location See Figure 2 - Boring Location Map
Gilbane Development - Madison Flats
13693.001
Drilling Method
8"
Feet
Hole Diameter
Moisture
Dry Density
N
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC
Sample No.

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE

STRENGTH
GEOTECHNICAL BORING LOG LB-4
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices CL
SM
SM
SM
ML
ML
113 5
R-1
R-2
R-3
R-4
S-1
R-5
CO
5 9
10 10
13 12
6 10
12 6
7 13
5 5
6 8
14 19
Artificial Fill (Afu):
@Surface: SILTY SAND WITH GRAVEL (SM), brown, slightly
moist, fine to coarse sand, 15% fines, 10% gravel (field estimate)
Old Alluvial Fan Deposits (Qof):
@2.5': LEAN CLAY WITH SAND (CL), stiff, brown, slightly moist, 85% medium plasticity fines (field estimate)
@5': SILTY SAND (SM), medium dense, brown, slightly moist, fine to medium sand, 30% fines (field estimate)
@7.5': SILTY SAND (SM), medium dense, brown, slightly moist, fine to coarse sand, 15% fines (field estimate)
@10': SANDY SILT (ML), stiff, brown, slightly moist, fine to coarse sand, 70% low to medium plasticity fines (field estimate) @15': SILT WITH SAND (ML), stiff, brown, slightly moist, fine sand, 85% low plasticity fines (field estimate)
@20': SILT WITH SAND (ML), very stiff, brown, slightly moist, fine sand, 85% low plasticity fines (field estimate)
TOTAL DEPTH = 21.5 FEET

NO GROUNDWATER ENCOUNTERED

BACKFILLED TO SURFACE WITH SOIL CUTTINGS
Project No.

Ground Elevation
Depth
Blows
Elevation
Per 6 Inches

Attitudes
SAMPLE TYPES:
2R Drilling
Content, %
Logged By
Date Drilled
855
850
845
840
835
830
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * * AA
Feet
S
(U.S.C.S.)
Log
Type of Tests
Graphic
pcf
857'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
AA
Hollow Stem Auger - Autohammer
0 5
10 15
20 25
30 Soil Class.
11-3-22

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Location See Figure 2 - Boring Location Map
Gilbane Development - Madison Flats
13693.001
Drilling Method
8"
Feet
Hole Diameter
Moisture
Dry Density
N
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC
Sample No.

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE

STRENGTH
GEOTECHNICAL BORING LOG LB-5
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices SM
ML
SM
SM
SM
ML
ML
SM
119
122
117
119
6 2
2 5
B-1
R-1
R-2
R-3
R-4
S-1
R-5
S-2
EI, RV
-200, AL
7 10
20 10
10 17
7 10
11 7
23 26
5 8
10 9
13 25
4 8
9 Artificial Fill (Afu):
@Surface: SILTY SAND WITH GRAVEL (SM), brown, slightly
moist, fine to coarse sand, 15% fines, 10% gravel (field estimate)
Old Alluvial Fan Deposits (Qof):
@2.5': SILT (ML), very stiff, brown, slightly moist, 90% low plasticity fines (field estimate)
@5': SILTY SAND (SM), medium dense, brown, slightly moist, fine to coarse sand, 30% fines (field estimate)
@7.5': SILTY SAND (SM), medium dense, brown, slightly moist, fine to medium sand, 40% low plasticity fines (field estimate) @10': SILTY SAND (SM), medium dense, brown, slightly moist, fine to medium sand, 45% low plasticity fines (lab)
@15': SANDY SILT (ML), very stiff, brown, slightly moist, fine to medium sand, 75% low plasticity fines (field estimate)
@20': SILT (ML), very stiff, brown, slightly moist, medium toughness, 90% low plasticity fines (field estimate)
@25': SILTY SAND (SM), medium dense, brown, slightly moist, fine to coarse sand, 40% fines (field estimate)
Project No.

Ground Elevation
Depth
Blows
Elevation
Per 6 Inches

Attitudes
SAMPLE TYPES:
2R Drilling
Content, %
Logged By
Date Drilled
855
850
845
840
835
830
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * * AA
Feet
S
(U.S.C.S.)
Log
Type of Tests
Graphic
pcf
858'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
AA
Hollow Stem Auger - Autohammer
0 5
10 15
20 25
30 Soil Class.
11-3-22

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Location See Figure 2 - Boring Location Map
Gilbane Development - Madison Flats
13693.001
Drilling Method
8"
Feet
Hole Diameter
Moisture
Dry Density
N
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC
Sample No.

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE

STRENGTH
GEOTECHNICAL BORING LOG LB-6
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices SP
ML
SM
SM
SM
SP-SM
R-6
S-3
R-7
S-4
R-8
AL13
27 27
6 10
17 14
26 40
6 18
22 24
38 46
@30': POORLY GRADED SAND (SP), medium dense, light brown, slightly moist, medium to coarse sand, 5% fines (field estimate) @30.5': SILT WITH SAND (ML), hard, brown, slightly moist, 80% low plasticity fines, (field estimate)
@35': SILTY SAND (SM), medium dense, brown, slightly moist, fine to coarse sand, 20% fines (field estimate)
@40': SILTY SAND (SM), dense, brown, slightly moist, medium to coarse sand, 15% fines (field estimate)
@45': SILTY SAND (SM)), dense, light brown, slightly moist, medium to coarse sand, 15% fines (field estimate)
@50': POORLY GRADED SAND with SILT (SP), very dense, light brown, slightly moist, medium to coarse sand, 10% fines (field estimate)
TOTAL DEPTH = 51.5 FEET

NO GROUNDWATER ENCOUNTERED

BACKFILLED TO SURFACE WITH SOIL CUTTINGS
Project No.

Ground Elevation
Depth
Blows
Elevation
Per 6 Inches

Attitudes
SAMPLE TYPES:
2R Drilling
Content, %
Logged By
Date Drilled
825
820
815
810
805
800
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * * AA
Feet
S
(U.S.C.S.)
Log
Type of Tests
Graphic
pcf
858'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
AA
Hollow Stem Auger - Autohammer
30 35
40 45
50 55
60 Soil Class.
11-3-22

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Location See Figure 2 - Boring Location Map
Gilbane Development - Madison Flats
13693.001
Drilling Method
8"
Feet
Hole Diameter
Moisture
Dry Density
N
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC
Sample No.

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE

STRENGTH
GEOTECHNICAL BORING LOG LB-6
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices ML
SM
SP
ML
ML
SM
SP
118
117
5 3
R-1
R-2
R-3
R-4
S-1
S-2
-200
10 13
14 6
4 2
6 8
11 11
23 28
4 7
7 6
8 9
Artificial Fill (Afu):
@Surface: SILTY SAND WITH GRAVEL (SM), brown, slightly
moist, fine to coarse sand, 15% fines 10% gravel (field estimate)
Old Alluvial Fan Deposits (Qof):
@2.5': SANDY SILT (ML), very stiff, brown, slightly moist, fine to coarse sand, 60% low plasticity fines (field estimate)
@5': SILTY SAND (SM), very loose, brown, slightly moist, medium to coarse sand, 18% fines (lab)
@7.5': POORLY GRADED SAND (SP), loose, light brown, slightly moist, fine to coarse sand, 5% fines (field estimate)
@8': SANDY SILT (ML), medium stiff, brown, slightly moist, fine sand, 70% low plasticity fines (field estimate)
@10': SILT WITH SAND (ML), very stiff, brown, slightly moist, 85% low plasticity fines (field estimate)
@15': SILTY SAND (SM), medium dense, brown, slightly moist, fine to coarse sand, 30% fines (field estimate)
@20': POORLY GRADED SAND (SP), loose, light brown, slightly moist, fine to coarse sand, 5% fines (field estimate)
TOTAL DEPTH = 21.5 FEET

NO GROUNDWATER ENCOUNTERED

BACKFILLED TO SURFACE WITH SOIL CUTTINGS
Project No.

Ground Elevation
Depth
Blows
Elevation
Per 6 Inches

Attitudes
SAMPLE TYPES:
2R Drilling
Content, %
Logged By
Date Drilled
855
850
845
840
835
830
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * * AA
Feet
S
(U.S.C.S.)
Log
Type of Tests
Graphic
pcf
858'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
AA
Hollow Stem Auger - Autohammer
0 5
10 15
20 25
30 Soil Class.
11-3-22

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Location See Figure 2 - Boring Location Map
Gilbane Development - Madison Flats
13693.001
Drilling Method
8"
Feet
Hole Diameter
Moisture
Dry Density
N
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC
Sample No.

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE

STRENGTH
GEOTECHNICAL BORING LOG LB-7
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices SM
SM
SM
ML
SM
SP-SM
SM
ML
S-1
S-2
S-3
-200
-200
4 5
7 4
6 7
2 3
3 Artificial Fill (Afu):
@Surface: SILTY SAND WITH GRAVEL (SM), brown, slightly
moist, fine to coarse sand, 15% fines, 10% gravel (field estimate)
Old Alluvial Fan Deposits (Qof):
@5': SILTY SAND (SM), brown, dry, fine to medium sand, 40% fines (field estimate)
@10': SILTY SAND (SM), brown, dry, fine to coarse sand, 40% fines (field estimate)
@15': SANDY SILT (ML), stiff, brown, slightly moist, fine to coarse sand, 70% low plasticity fines (field estimate)
@17': SILTY SAND (SM), medium dense, brown, slightly moist, fine sand, 28% fines (lab)
@18.25': POORLY GRADED SAND WITH SILT (SP-SM), medium
dense, brown, slightly moist, fine sand, 10% fines (field estimate)
@20': SILTY SAND (SM), loose, brown, slightly moist, fine sand, 38% fines (lab)
@21': SANDY SILT (ML), medium stiff, brown, slightly moist, fine sand, 80% low plasticity fines (field estimate)
TOTAL DEPTH = 21.5 FEET

NO GROUNDWATER ENCOUNTERED
INFILTRATION TEST PERFORMED FROM 16 TO 21 FEET
Project No.

Ground Elevation
Depth
Blows
Elevation
Per 6 Inches

Attitudes
SAMPLE TYPES:
2R Drilling
Content, %
Logged By
Date Drilled
860
855
850
845
840
835
830
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * * AA
Feet
S
(U.S.C.S.)
Log
Type of Tests
Graphic
pcf
860'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
AA
Hollow Stem Auger - Autohammer
0 5
10 15
20 25
30 Soil Class.
11-4-22

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Location See Figure 2 - Boring Location Map
Gilbane Development - Madison Flats
13693.001
Drilling Method
8"
Feet
Hole Diameter
Moisture
Dry Density
N
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC
Sample No.

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE

STRENGTH
GEOTECHNICAL BORING LOG IT-1
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices SM
SC
SM
ML
S-1
S-2 -200
2 2
4 3
3 4
Artificial Fill (Afu):
@Surface: SILTY SAND WITH GRAVEL (SM), brown, slightly
moist, fine to coarse sand, 15% fines, 10% gravel (field estimate)
Old Alluvial Fan Deposits (Qof):
@5': CLAYEY SAND (SC), brown, slightly moist, 35% fines (field estimate)
@10': SILTY SAND (SM), loose, brown, slightly moist, fine sand, 30% fines (field estimate)
4-inch lense of SP @10.25'
@13.5': SILTY SAND (SM), loose, brown, slightly moist, fine sand, 55% fines (lab)
TOTAL DEPTH = 15 FEET

NO GROUNDWATER ENCOUNTERED
INFILTRATION TEST PERFORMED FROM 10 TO 15 FEET
Project No.

Ground Elevation
Depth
Blows
Elevation
Per 6 Inches

Attitudes
SAMPLE TYPES:
2R Drilling
Content, %
Logged By
Date Drilled
860
855
850
845
840
835
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * * AA
Feet
S
(U.S.C.S.)
Log
Type of Tests
Graphic
pcf
862'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
AA
Hollow Stem Auger - Autohammer
0 5
10 15
20 25
30 Soil Class.
11-4-22

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Location See Figure 2 - Boring Location Map
Gilbane Development - Madison Flats
13693.001
Drilling Method
8"
Feet
Hole Diameter
Moisture
Dry Density
N
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC
Sample No.

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE

STRENGTH
GEOTECHNICAL BORING LOG IT-2
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices SM
SM
SM
ML
SM
Artificial Fill (Afu):
@Surface: SILTY SAND WITH GRAVEL (SM), brown, slightly
moist, fine to coarse sand, 15% fines, 30% gravel (field estimate)
Old Alluvial Fan Deposits (Qof):
@5': SILTY SAND (SM), brown, slightly moist, fine to medium sand @5': SILTY SAND (SM), brown, slightly moist, fine to coarse sand @15': SANDY SILT (ML), brown, dry to moist, fine sand, 60% fines (field estimate)
@25': SILTY SAND (SM), brown, slightly moist, fine to medium sand, 40% fines (field estimate)
Project No.

Ground Elevation
Depth
Blows
Elevation
Per 6 Inches

Attitudes
SAMPLE TYPES:
2R Drilling
Content, %
Logged By
Date Drilled
855
850
845
840
835
830
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * * AA
Feet
S
(U.S.C.S.)
Log
Type of Tests
Graphic
pcf
857'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
AA
Hollow Stem Auger - Autohammer
0 5
10 15
20 25
30 Soil Class.
11-4-22

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Location See Figure 2 - Boring Location Map
Gilbane Development - Madison Flats
13693.001
Drilling Method
8"
Feet
Hole Diameter
Moisture
Dry Density
N
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC
Sample No.

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE

STRENGTH
GEOTECHNICAL BORING LOG IT-3
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices SM
SM
SC
ML
SP
S-1
S-2
S-3 -200
13 19
32 10
19 21
5 10
11 @30': SILTY SAND (SM), brown, slightly moist, fine to medium sand, 40% fines (field estimate)
@40': SILTY SAND (SM), brown, slightly moist, fine to coarse sand, 40% fines (field estimate)
@43': SILTY CLAYEY SAND (SC-SM), very dense, brown, slightly moist, fine to coarse sand, 45% fines (field estimate)
@45': SANDY SILT (ML), hard, brown, slightly moist, fine to coarse sand, 70% low plasticity fines (field estimate)
-Small lenses of SP
@47': SILTY SAND (SM), medium dense, brown, slightly moist, medium to coarse sand, 15% fines (lab)
TOTAL DEPTH = 48.5 FEET

NO GROUNDWATER ENCOUNTERED
INFILTRATION TEST PERFORMED FROM 43 TO 48 FEET
Project No.

Ground Elevation
Depth
Blows
Elevation
Per 6 Inches

Attitudes
SAMPLE TYPES:
2R Drilling
Content, %
Logged By
Date Drilled
825
820
815
810
805
800
* * * This log is a part of a report by Leighton and should not be used as a stand-alone document. * * * AA
Feet
S
(U.S.C.S.)
Log
Type of Tests
Graphic
pcf
857'

BULK SAMPLE

CORE SAMPLE

GRAB SAMPLE

RING SAMPLE

SPLIT SPOON SAMPLE

TUBE SAMPLE
B
C
G
R
S
T
AA
Hollow Stem Auger - Autohammer
30 35
40 45
50 55
60 Soil Class.
11-4-22

SOIL DESCRIPTION
Sampled By
Drilling Co.Drilling Co.

Project
Location See Figure 2 - Boring Location Map
Gilbane Development - Madison Flats
13693.001
Drilling Method
8"
Feet
Hole Diameter
Moisture
Dry Density
N
This Soil Description applies only to a location of the exploration at the time of sampling. Subsurface conditions may differ at other locations and may change with time. The description is a simplification of the actual conditions encountered. Transitions between soil types may be gradual.

TYPE OF TESTS:
-200
AL
CN
CO
CR
CU
% FINES PASSING

ATTERBERG LIMITS

CONSOLIDATION

COLLAPSE

CORROSION

UNDRAINED TRIAXIAL
DS
EI
H
MD
PP
RV

DIRECT SHEAR

EXPANSION INDEX

HYDROMETER

MAXIMUM DENSITY

POCKET PENETROMETER

R VALUE
SA
SE
SG
UC
Sample No.

SIEVE ANALYSIS

SAND EQUIVALENT

SPECIFIC GRAVITY

UNCONFINED COMPRESSIVE

STRENGTH
GEOTECHNICAL BORING LOG IT-3
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Results of Falling Head Infiltration Test
Project: 13693.001 Initial estimated Depth to Water Surface (in.): 210 Exploration #/Location: IT-1 Average depth of water in well, "h" (in.): 29 Cross‐sectional area for flow calcs based on h Depth Boring drilled, bgs (ft): 21 approx. h/r: 7.2 Well pack sand porosity  0.3 Tested by: AA Tu (Fig. 8) (ft): 82.5 Casing outer diameter, in. 2.3 USCS Soil Type in test zone: SM/ML Tu>3h?: yes, OK Casing inner diameter, in. 2.1 Weather (start to finish): Sunny Cross‐sectional area, in.^2 17.3 Water Source/pH: H2O Hydrant
Measured boring diameter: 8 in. 4 in. Well Radius
Depth to GW or aquitard, bgs: 100 ft
Well Prep: Drilled to 21 feet bgs ,pipe set at 20.14 ft bgs, bottom 10 foo t screened and #3 sand placed around anulus to 10 ft bgs Use of Barrels: No ft in. Total (in.) Use of Flow Meter: No
Depth to bottom of well measured from top of a 20. ft 0. in. 240 Depth of well bottom below top of casing (in): 241 Test Type: Falling Head Casing stickup measured above top of auger (or ground 1. in. 1 Depth to top of sand from top of casing 10. ft
Field Data Calculations
Refilled?
Start Date Start time: Total
11/7/2022 12:00 ft in.
11/7/22 12:10 17.0 10 203.1 36.9 #### ###### ##### ####### #VALUE! 11/7/22 12:12 17.2 2 12 204.8 35.2 -1.68 36 0 29 29 15 872 0.9 0.21 0.84 11/7/22 12:15 17.3 3 15 206.6 33.4 -1.8 34 0 31 31 10 623 0.9 0.16 0.63 11/7/22 12:20 17.56 5 20 209.7 30.3 -3.12 32 0 54 54 11 648 0.9 0.20 0.70 11/7/22 12:25 17.75 5 25 212.0 28.0 -2.28 29 0 39 39 8 473 0.9 0.16 0.56 11/7/22 12:35 18.13 10 35 216.6 23.4 -4.56 26 0 79 79 8 473 0.9 0.22 0.63 11/7/22 12:45 18.5 10 45 221.0 19.0 -4.44 21 0 77 77 8 461 0.9 0.29 0.73 11/7/22 12:55 19.24 10 55 229.9 10.1 -8.88 15 0 154 154 15 922 0.9 1.64 2.04 11/7/22 13:00 19.37 5 60 231.4 8.6 -1.56 9 0 27 27 5 324 0.9 0.60 1.05 Refilled 60 231.4 8.6 #### ###### ##### ####### #VALUE! 11/7/22 13:01 16.35 61 195.2 44.8 #### ###### ##### ####### #VALUE! 11/7/22 13:03 16.60 2 63 198.2 41.8 -3 43 0 52 52 26 1557 0.9 0.28 1.26 11/7/22 13:05 16.69 2 65 199.3 40.7 -1.08 41 0 19 19 9 560 0.9 0.11 0.48 11/7/22 13:10 16.93 5 70 202.2 37.8 -2.88 39 0 50 50 10 598 0.9 0.13 0.53 11/7/22 13:20 17.32 10 80 206.8 33.2 -4.68 36 0 81 81 8 486 0.9 0.13 0.48 11/7/22 13:30 17.63 10 90 210.6 29.4 -3.72 31 0 64 64 6 386 0.9 0.12 0.43 11/7/22 13:40 17.89 10 100 213.7 26.3 -3.12 28 0 54 54 5 324 0.9 0.12 0.40 11/7/22 13:50 18.18 10 110 217.2 22.8 -3.48 25 0 60 60 6 361 0.9 0.17 0.50 11/7/22 14:00 18.48 10 120 220.8 19.2 -3.6 21 0 62 62 6 374 0.9 0.23 0.59 11/7/22 14:10 19.09 10 130 228.1 11.9 -7.32 16 0 127 127 13 760 0.9 1.01 1.59 11/7/22 14:15 19.3 5 135 230.6 9.4 -2.52 11 0 44 44 9 523 0.9 0.88 1.52 Refilled 135 230.6 9.4 #### ###### ##### ####### #VALUE! 11/7/22 14:17 16.37 137 195.4 44.6 #### ###### ##### ####### #VALUE! 11/7/22 14:20 16.56 3 140 197.7 42.3 -2.28 43 0 39 39 13 789 0.9 0.14 0.64 11/7/22 14:25 16.78 5 145 200.4 39.6 -2.64 41 0 46 46 9 548 0.9 0.11 0.47 11/7/22 14:35 17.15 10 155 204.8 35.2 -4.44 37 0 77 77 8 461 0.9 0.11 0.43 11/7/22 14:40 17.52 5 160 209.2 30.8 -4.44 33 0 77 77 15 922 0.9 0.27 0.97 11/7/22 15:00 17.88 20 180 213.6 26.4 -4.32 29 0 75 75 4 224 0.9 0.08 0.27 11/7/22 15:10 18.08 10 190 216.0 24.0 -2.4 25 0 42 42 4 249 0.9 0.11 0.34 11/7/22 15:20 18.32 10 200 218.8 21.2 -2.88 23 0 50 50 5 299 0.9 0.16 0.45 Refilled 200 218.8 21.2 #### ###### ##### ####### #VALUE! 11/7/22 15:23 17.1 203 204.2 35.8 #### ###### ##### ####### #V ALUE! 11/7/22 15:25 17.21 2 205 205.5 34.5 -1.32 35 0 23 23 11 685 0.9 0.17 0.68 11/7/22 15:37 17.61 12 217 210.3 29.7 -4.8 32 0 83 83 7 415 0.9 0.13 0.45 11/7/22 15:45 17.82 8 225 212.8 27.2 -2.52 28 0 44 44 5 327 0.9 0.12 0.39 11/7/22 15:55 18.05 10 235 215.6 24.4 -2.76 26 0 48 48 5 286 0.9 0.12 0.38 11/7/22 16:05 18.3 10 245 218.6 21.4 -3 23 0 52 52 5 311 0.9 0.16 0.46 11/7/22 16:10 18.4 5 250 219.8 20.2 -1.2 21 0 21 21 4 249 0.9 0.14 0.40 250 219.8 20.2 #### ###### ##### ####### #VALUE!
250 219.8 20.2 #### ###### ##### ####### #VALUE!
250 219.8 20.2 #### ###### ##### ####### #VALUE!
250 219.8 20.2 #### ###### ##### ####### #VALUE!
250 219.8 20.2 #### ###### ##### ####### #VALUE!
250 219.8 20.2 #### ###### ##### ####### #VALUE!
250 219.8 20.2 #### ###### ##### ####### #VALUE!
250 219.8 20.2 #### ###### ##### ####### #VALUE!
250 219.8 20.2 #### ###### ##### ####### #VALUE!
Minimum Rate: 0.27
Raw Rate for design, prior to application of adjustment factors : 0.58 Date Time Depth to WL in
Boring
(measured
from top of
casing)
Water
Temp
(deg F)
Average
Infiltration
Surface
Area,
(in^2)
V
(Fig 9)
K20,
Coef. Of
Perme-
ability at
20 deg C
(in./hr)
Infiltration
Rate
[flow/surf
area] (in./hr)
(FS=1)
Vol Change (in.^3)
(or
Comments)
from
supply
from
h
Flow
(in^3/
min)
q,
Flow
(in^3/ hr)
Depth to
WL in
well (in.)
h,
Height of
Water in
Well (in.)
h (in.) Avg. hΔt
(min)
Total
Elapsed
Time
(min)
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Results of Well Permeameter, from USBR 7300-89 Method
Project: 13693.001 Initial estimated Depth to Water Surface (in.): 117 Exploration #/Location: IT-2 Average depth of water in well, "h" (in.): 63 Cross‐sectional area for flow calcs based on  h Depth Boring drilled, bgs (ft): 15 approx. h/r: 15.8 Well pack sand porosity  0.3 Tested by: AA Tu (Fig. 8) (ft): 90.2 Casing outer diameter, in. 2.3 USCS Soil Type in test zone: SM Tu>3h?: yes, OK Casing inner diameter, in. 2.1 Weather (start to finish): Rain Cross‐sectional area, in.^2 17.3 Water Source/pH: H2O
Measured boring diameter: 8 in. 4 in. Well Radius
Depth to GW or aquitard, bgs: 100 ft
Well Prep: Drilled to 15 feet bgs ,pipe set at 15.15ft bgs, bottom 10 foot screened and #3 sand placed around anulus to 5 ft bgs Use of Barrels: No ft in. Total (in.) Use of Flow Meter: Yes
Depth to bottom of well measured from top of auger (or ground surface) 15.1 ft 0. in. 181 Depth of well bottom below top of casing (in): 182 Test Type: Constant Head Casing stickup measured above top of auger (or ground surface) (+ is up) 0. ft 1. in. 1 Depth to top of sand from top of casing 5. ft 0. in.

Flow Meter ID: 2497 Meter Units: Gallons 0.05 gallons/pulse Data logger ID:

Field Data Calculations
Refilled?
Start Date Start time: Total
11/7/2022 7:30 Gallons ft in.
11/7/22 7:49 1786.97 10.3 19 122.6 58.6 #### ###### ##### ####### #VALUE! 11/7/22 7:51 1787.82 10.19 2 21 121.3 59.9 1.32 59 196 -23 174 87 5206 0.9 0.52 3.12 11/7/22 Adjusted Flow 21 121.3 59.9 #### ###### ##### ####### #VALUE! 11/7/22 7:54 1788.66 10.06 24 119.7 61.5 #### ###### ##### ####### #VALUE! 11/7/22 7:56 1789.41 9.96 2 26 118.5 62.7 1.2 62 173 -21 152 76 4575 0.9 0.43 2.62 11/7/22 7:58 1790.07 9.93 2 28 118.2 63.0 0.36 63 152 -6 146 73 4387 0.9 0.41 2.48 11/7/22 8:00 1790.66 9.88 2 30 117.6 63.6 0.6 63 136 -10 126 63 3777 0.9 0.34 2.12 11/7/22 Adjusted Flow 30 117.6 63.6 #### ###### ##### ####### #VALUE! 11/7/22 8:05 1791.44 10.33 35 123.0 58.2 #### ###### ##### ####### #VALUE! 11/7/22 8:08 1792.11 10.51 3 38 125.1 56.1 -2.16 57 155 37 192 64 3843 0.9 0.43 2.38 11/7/22 8:10 1792.73 10.18 2 40 121.2 60.0 3.96 58 143 -68 75 37 2242 0.9 0.22 1.37 11/7/22 8:15 1793.74 10.23 5 45 121.8 59.4 -0.6 60 233 10 244 49 2924 0.9 0.30 1.74 11/7/22 8:20 1794.18 10.22 5 50 121.6 59.6 0.12 60 102 -2 100 20 1195 0.9 0.12 0.71 11/7/22 8:30 1796.32 10.14 10 60 120.7 60.5 0.96 60 494 -17 478 48 2866 0.9 0.28 1.69 11/7/22 8:40 1798.37 10.07 10 70 119.8 61.4 0.84 61 474 -15 459 46 2754 0.9 0.27 1.61 11/7/22 8:50 1800.54 10.01 10 80 119.1 62.1 0.72 62 501 -12 489 49 2933 0.9 0.28 1.69 11/7/22 9:00 1802.68 9.97 10 90 118.6 62.6 0.48 62 494 -8 486 49 2916 0.9 0.27 1.66 11/7/22 9:10 1804.8 9.91 10 100 117.9 63.3 0.72 63 490 -12 477 48 2864 0.9 0.26 1.62 11/7/22 9:20 1806.95 9.89 10 110 117.7 63.5 0.24 63 497 -4 492 49 2955 0.9 0.27 1.66 11/7/22 9:30 1809.09 9.87 10 120 117.4 63.8 0.24 64 494 -4 490 49 2941 0.9 0.27 1.64 11/7/22 9:40 1811.23 9.83 10 130 117.0 64.2 0.48 64 494 -8 486 49 2916 0.9 0.26 1.62 11/7/22 9:50 1813.38 9.82 10 140 116.8 64.4 0.12 64 497 -2 495 49 2967 0.9 0.27 1.64 11/7/22 10:00 1815.53 9.79 10 150 116.5 64.7 0.36 65 497 -6 490 49 2943 0.9 0.26 1.62 11/7/22 10:11 1817.89 9.76 11 161 116.1 65.1 0.36 65 545 -6 539 49 2940 0.9 0.26 1.61 11/7/22 10:20 1819.81 9.75 9 170 116.0 65.2 0.12 65 444 -2 441 49 2943 0.9 0.26 1.61 11/7/22 10:30 1821.9 9.74 10 180 115.9 65.3 0.12 65 483 -2 481 48 2884 0.9 0.25 1.57 11/7/22 10:40 1824.03 9.72 10 190 115.6 65.6 0.24 65 492 -4 488 49 2927 0.9 0.25 1.59 11/7/22 10:50 1826.17 9.69 10 200 115.3 65.9 0.36 66 494 -6 488 49 2929 0.9 0.25 1.59 11/7/22 11:00 1828.31 9.68 10 210 115.2 66.0 0.12 66 494 -2 492 49 2954 0.9 0.25 1.59 11/7/22 11:10 1830.46 9.67 10 220 115.0 66.2 0.12 66 497 -2 495 49 2967 0.9 0.25 1.60 11/7/22 11:20 1832.57 9.64 10 230 114.7 66.5 0.36 66 487 -6 481 48 2887 0.9 0.25 1.55 11/7/22 11:30 1834.7 9.63 10 240 114.6 66.6 0.12 67 492 -2 490 49 2940 0.9 0.25 1.57 240 114.6 66.6 #### ###### ##### ####### #VALUE!
240 114.6 66.6 #### ###### ##### ####### #VALUE!
240 114.6 66.
6 #### ###### ##### ####### #VALUE!
0 0.0 181.2 #### ###### ##### ####### #VALUE!
0 0.0 181.2 #### ###### ##### ####### #VALUE!
0 0.0 181.2 #### ###### ##### ####### #VALUE!
0 0.0 181.2 #### ###### ##### ####### #VALUE!
0 0.0 181.2 #### ###### ##### ####### #VALUE!
0 0.0 181.2 #### ###### ##### ####### #VALUE!
0 0.0 181.2 #### ###### ##### ####### #VALUE!
Minimum Rate: 0.71
Raw Rate for design, prior to application of adjustment factors : 1.57 Water
Temp
(deg F)Reading
(gallons)
Interval
Pulse
Count
(or
Comments)
Date Time Water
Level in
Supply
Barrel
(in.)
Data from Flow
Meter Depth to WL
in Boring
(measured
from top of
casing)
Average
Infiltratio
n Surface
Area,
(in^2)
V
(Fig 9)
K20,
Coef. Of
Perme-
ability at
20 deg C
(in./hr)
Infiltration
Rate
[flow/surf
area] (in./hr)
(FS=1)
Vol Change (in.^3)
from
supply
from
h
Flow
(in^3/
min)
q,
Flow
(in^3/
hr)
Δt
(min)
Total
Elapsed
Time
(min)
Depth to
WL in
well (in.)
h,
Height of
Water in
Well (in.)
h
(in.) Avg. h
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Results of Falling Head Infiltration Test
Project: 13693.001 Initial estimated Depth to Water Surface (in.): 514 Exploration #/Location: IT-3 Average depth of water in well, "h" (in.): 39 Cross‐sectional area for flow calcs based on h Depth Boring drilled, bgs (ft): 48 approx. h/r: 9.7 Well pack sand porosity  0.3 Tested by: AA Tu (Fig. 8) (ft): 57.2 Casing outer diameter, in. 2.3 USCS Soil Type in test zone: SP/ML Tu>3h?: yes, OK Casing inner diameter, in. 2.1 Weather (start to finish): Sunny Cross‐sectional area, in.^2 17.3 Water Source/pH: H2O Hydrant
Measured boring diameter: 8 in. 4 in. Well Radius
Depth to GW or aquitard, bgs: 100 ft
Well Prep: Drilled to 48 feet bgs ,pipe set at 48.3 ft bgs, bottom 10 foot screened and #3 sand placed around anulus to 38 ft bgs Use of Barrels: No ft in. Total (in.) Use of Flow Meter: No
Depth to bottom of well measured from top of a 48.3 ft 0. in. 580 Depth of well bottom below top of casing (in): 607 Test Type: Falling Head Casing stickup measured above top of auger (o 2. ft 3. in. 27 Depth to top of sand from top of casing 38. ft
Flow Meter ID: 0.05 gallons/pulse Data logger ID:

Field Data Calculations
Refilled?
Start Date Start time: Total
11/4/2022 11:00 ft in.
11/4/22 11:33 45.67 33 521.0 58.6 #### ###### ##### ####### #VALUE! 11/4/22 11:35 45.9 2 35 523.7 55.9 -2.64 57 0 46 46 23 1370 0.9 0.16 0.85 11/4/22 11:37 46.08 2 37 526.0 53.6 -2.28 55 0 39 39 20 1183 0.9 0.14 0.76 11/4/22 11:40 46.34 3 40 529.1 50.5 -3.12 52 0 54 54 18 1079 0.9 0.14 0.73 11/4/22 11:42 46.46 2 42 530.5 49.1 -1.44 50 0 25 25 12 747 0.9 0.10 0.53 11/4/22 11:45 46.68 3 45 533.2 46.4 -2.64 48 0 46 46 15 913 0.9 0.14 0.67 11/4/22 11:48 46.86 3 48 535.3 44.3 -2.16 45 0 37 37 12 747 0.9 0.12 0.58 11/4/22 11:51 47.07 3 51 537.8 41.8 -2.52 43 0 44 44 15 872 0.9 0.16 0.71 11/4/22 11:55 47.30 4 55 540.6 39.0 -2.76 40 0 48 48 12 716 0.9 0.15 0.62 11/4/22 12:00 47.59 5 60 544.1 35.5 -3.48 37 0 60 60 12 722 0.9 0.17 0.67 11/4/22 12:05 47.92 5 65 548.0 31.6 -3.96 34 0 68 68 14 822 0.9 0.23 0.85 11/4/22 12:09 48.31 4 69 552.7 26.9 -4.68 29 0 81 81 20 1214 0.9 0.45 1.43 11/4/22 12:15 49.15 6 75 562.8 16.8 -10.08 22 0 174 174 29 1744 0.9 1.42 2.68 11/4/22 12:20 49.75 5 80 570.0 9.6 -7.2 13 0 125 125 25 1494 0.9 2.78 3.61 Refilled 80 570.0 9.6 #### ###### ##### ####### #VALUE! 11/4/22 12:25 44.77 85 510.2 69.4 #### ###### ##### ####### #VALUE! 11/4/22 12:30 45.55 5 90 519.6 60.0 -9.36 65 0 162 162 32 1943 0.9 0.20 1.07 11/4/22 12:37 45.7 7 97 521.4 58.2 -1.8 59 0 31 31 4 267 0.9 0.03 0.16 11/4/22 12:40 45.75 3 100 522.0 57.6 -0.6 58 0 10 10 3 208 0.9 0.02 0.13 11/4/22 12:45 45.88 5 105 523.6 56.0 -1.56 57 0 27 27 5 324 0.9 0.04 0.20 11/4/22 12:49 45.97 4 109 524.6 55.0 -1.08 55 0 19 19 5 280 0.9 0.03 0.18 11/4/22 12:55 46.12 6 115 526.4 53.2 -1.8 54 0 31 31 5 311 0.9 0.04 0.20 11/4/22 13:05 46.3 10 125 528.6 51.0 -2.16 52 0 37 37 4 224 0.9 0.03 0.15 11/4/22 13:15 46.46 10 135 530.5 49.1 -1.92 50 0 33 33 3 199 0.9 0.03 0.14 11/4/22 13:25 46.64 10 145 532.7 46.9 -2.16 48 0 37 37 4 224 0.9 0.03 0.16 11/4/22 13:35 46.78 10 155 534.4 45.2 -1.68 46 0 29 29 3 174 0.9 0.03 0.13 11/4/22 13:45 46.89 10 165 535.7 43.9 -1.32 45 0 23 23 2 137 0.9 0.02 0.11 11/4/22 13:58 47.05 13 178 537.6 42.0 -1.92 43 0 33 33 3 153 0.9 0.03 0.13 11/4/22 14:08 47.17 10 188 539.0 40.6 -1.44 41 0 25 25 2 149 0.9 0.03 0.13 11/4/22 14:15 47.24 7 195 539.9 39.7 -0.84 40 0 15 15 2 125 0.9 0.02 0.11 11/4/22 14:25 47.35 10 205 541.2 38.4 -1.32 39 0 23 23 2 137 0.9 0.03 0.12 11/4/22 14:40 47.5 15 220 543.0 36.6 -1.8 37 0 31 31 2 125 0.9 0.03 0.12 11/4/22 14:50 47.59 10 230 544.1 35.5 -1.08 36 0 19 19 2 112 0.9 0.03 0.11 11/4/22 15:00 47.7 10 240 545.4 34.2 -1.32 35 0 23 23 2 137 0.9 0.03 0.14 11/4/22 15:10 47.77 10 250 546.2 33.4 -0.84 34 0 15 15 1 87 0.9 0.02 0.09 11/4/22 15:20 47.87 10 260 547.4 32.2 -1.2 33 0 21 21 2 125 0.9 0.03 0.13 11/4/22 15:30 47.97 10 270 548.6 31.0 -1.2 32 0 21 21 2 125 0.9 0.04 0.14 11/4/22 15:40 48.07 10 280 549.8 29.8 -1.2 30 0 21 21 2 125 0.9 0.04 0.14 11/4/22 15:50 48.15 10 290 550.8 28.8 -0.96 29 0 17 17 2 100 0.9 0.03 0.12 11/4/22 16:00 48.25 10 300 552.0 27.6 -1.2 28 0 21 21 2 125 0.9 0.04 0.15 11/4/22 16:10 48.36 10 310 553.3 26.3 -1.32 27 0 23 23 2 137 0.9 0.05 0.17 11/4/22 16:20 48.51 10 320 555.1 24.5 -1.8 25 0 31 31 3 187 0.9 0.08 0.25 11/4/22 16:30 48.77 10 330 558.2 21.4 -3.12 23 0 54 54 5 324 0.9 0.17 0.48 11/4/22 16:40 49 10 340 561.0 18.6 -2.76 20 0 48 48 5 286 0.9 0.18 0.48 11/4/22 16:50 49.18 10 350 563.2 16.4 -2.16 18 0 37 37 4 224 0.9 0.17 0.42 11/4/22 17:00 49.35 10 360 565.2 14.4 -2.04 15 0 35 35 4 212 0.9 0.19 0.45 11/4/22 17:10 49.54 10 370 567.5 12.1 -2.28 13 0 39 39 4 237 0.9 0.28 0.57 Minimum Rate: 0.09
Raw Rate for design, prior to application of adjustment factors: 0.20 Δt
(min)
Total
Elapsed
Time
(min)
Depth to
WL in
well (in.)
h,
Height of
Water in
Well (in.)
h (in.) Avg. h
Average
Infiltration
Surface
Area,
(in^2)
V
(Fig 9)
K20,
Coef. Of
Perme-
ability at
20 deg C
(in./hr)
Infiltration
Rate
[flow/surf
area] (in./hr)
(FS=1)
Vol Change (in.^3)
from
supply
from
h
Flow
(in^3/
min)
q,
Flow
(in^3/ hr)
Water
Temp
(deg F) (or
Comments)
Date Time Depth to WL in
Boring
(measured
from top of
casing)
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices

APPENDIX C

LABORATO

RY TEST RESULTS
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Compaction; LB-3, B-1 (11-03-22)
Tested By: F. Mina Date: 11/16/22
Input By: M. Vinet Date: 11/17/22
LB-3 Depth (ft.): 0 - 5.0
X Moist Mechanical Ram
Dry Manual Ram
Mold Volume (ft³) 0.03340 Ram Weight = 10 lb.; Drop = 18 in. 1 2 3 4 5 6
5590 5700 5745 5652
3528 3528 3528 3528
2062 2172 2217 2124
1518.4 1427.4 1485.8 1395.4
1463.8 1355.8 1390.0 1288.4
279.9 277.6 278.9 276.5

4.6 6.6 8.6 10.6
136.1 143.4 146.3 140.2
130.1 134.4 134.7 126.8
135.3 7.8

PROCEDURE USED
Procedure A
Soil Passing No. 4 (4.75 mm) Sieve
Mold : 4 in. (101.6 mm) diameter
Layers : 5 (Five)
Blows per layer : 25 (twenty-five)
May be used if +#4 is 20% or less
X Procedure B
Soil Passing 3/8 in. (9.5 mm) Sieve
Mold : 4 in. (101.6 mm) diameter
Layers : 5 (Five)
Blows per layer : 25 (twenty-five)
Use if +#4 is >20% and +3/8 in. is
20% or less
Procedure C
Soil Passing 3/4 in. (19.0 mm) Sieve
Mold : 6 in. (152.4 mm) diameter
Layers : 5 (Five)
Blows per layer : 56 (fifty-six)
Use if +3/8 in. is >20% and +¾ in.
is <30%
Particle-Size Distribution:
7:52:41
GR:SA:FI
Atterberg Limits:

LL,PL,PI
Optimum Moisture Content (%) Maximum Dry Density (pcf) Net Weight of Soil (g)
Wet Density (pcf)
Dry Density (pcf)
Moisture Content (%)
Wet Weight of Soil + Cont. (g)
Dry Weight of Soil + Cont. (g)
Weight of Container (g)
Weight of Mold (g)
Preparation Method:

Wt. Compacted Soil + Mold (g)
B-1
13693.001
TEST NO.

Soil Identification:

Sample No.:

Silty Sand (SM), Yellowish Brown.

MODIFIED PROCTOR COMPACTION TEST
ASTM D 1557
Project No.:

Boring No.:

Madison Flats/GeoProject Name:
120.0
125.0
130.0
135.0
140.0

0.0 5.0 10.0 15.0 20.

Dry Density (pcf)
Moisture Content (%)
SP. GR. = 2.70
SP. GR. = 2.75
SP. GR. = 2.80
XX
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Project Name: Tested By: MRV Date: 11/16/22
Project No.: 13693.001 Checked By: MRV Date: 11/17/22
Boring No.: LB-3 Depth (feet): 0 - 5.0
Sample No.: B-1
Soil Identification: Silty Sand (SM), Yellowish Brown.

Whole Sample Sample Passing
#4 Whole Sample Sample
passing #4
BA BA Wt. of Air-Dry Soil + Cont.(g) 1382.5 589.7
1382.5 589.7 Wt. of Dry Soil + Cont. (g) 1334.3 589.7 278.7 278.7 Wt. of Container No._____(g) 278.7 278.7
1055.3 311.0 Moisture Content (%) 4.6 0.0
BA
467.1
278.7
188.4
(mm.)
1 1/2"
1"
3/4"
1/2"
3/8"
#4
#8
#16
#30
#50
#100
#200
GRAVEL: 7 %
SAND: 52 %
FINES: 41 %
GROUP SYMBOL: SM N/A
N/A
Remarks:
175.0

52.0 80.6
111.4
142.1

0.075
PAN

22.9 36.3

71.04.750

2.360

1.180

0.600

0.300

0.150
Passing #4 Material After Wet Sieve

37.500
U. S. Sieve Size

25.000

19.000

12.500

9.500
Whole Sample

96.6 100.0

93.3 87.8

40.8 100.0

59.9 50.7
Wt. Air-Dried Soil + Cont.(g)

97.8 Cumulative Weight of Dry Soil Retained (g)
Sample Passing #4

PARTICLE-SIZE DISTRIBUTION (GRADATION)
ASTM D 6913
Container No.:

Madison Flats/Geo
Moisture ContentsCalculation of Dry Weights
of SOILS USING SIEVE ANALYSIS
Dry Wt. of Soil (g)

0.0 Wt. of Container (g)
Container No.
100.0

77.7 69.1
Percent Passing
(%)
Wt. of Dry Soil + Container (g)
Wt. of Container (g)
Dry Wt. of Soil Retained on # 200 Sieve (g)

18.2 Cu = D60/D10 =
Cc = (D30)²/(D60*D10) =
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices 7 : 52 : 41
B-1
Nov-22
Boring No.:

Depth (feet): 0 - 5.0 Soil Type :

Project Name:

PARTICLE - SIZE

DISTRIBUTION
ASTM D 6913
Soil Identification: Silty Sand (SM), Yellowish Brown.

SM
GR:SA:FI : (%)
Madison Flats/Geo
Project No.:

LB-3 Sample No.:
13693.001
SAND

SILT FINE

HYDROMETER

3.0" 1 1/2" 3/4" 3/8" #4 #8 #16 #30 #50 #100 #200 U.S. STANDARD SIEVE OPENING U.S. STANDARD SIEVE NUMBER

GRAVEL FINES

FINE CLAY COARSE COARSE MEDIUM
0 10
20 30
40 50
60 70
80 90
100

0.0010.0100.1001.00010.000100.000

PERCENT FINER BY WEIGHT
PARTICLE - SIZE (mm)
"
Sieve; LB-3, B-1 (11-03-22)
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices LB-1 LB-2 LB-3 LB-3 LB-6 LB-7 IT-1 IT-1
S-1 R-2 R-3 S-1 R-4 R-2 S-2 S-3

15.0 5.0 7.5 15.0 10.0 5.0 17.0 20.0

SPT RING RING SPT RING RING SPT SPT
10 10 10 10 10 10 10 10
634.1 609.5 606.9 629.7 622.2 616.0 609.4 550.0
628.6 595.0 587.1 624.6 605.0 607.0 593.6 528.7
279.5 280.5 276.4 280.2 278.0 278.2 278.1 278.1

1.6 4.6 6.4 1.5 5.3 2.7 5.0 8.5
PO WO R2 M MA 86 K2 BA
628.6 595.0 587.1 624.6 605.0 607.0 593.6 528.7
279.5 280.5 276.4 280.2 278.0 278.2 278.1 278.1
349.1 314.5 310.7 344.4 327.0 328.8 315.5 250.6
PO WO R2 M MA 86 K2 BA
609.8 467.6 456.7 607.1 458.1 549.2 521.6 432.4
279.5 280.5 276.4 280.2 278.0 278.2 278.1 278.1
330.3 187.1 180.3 326.9 180.1 271.0 243.5 154.3
5 41 42 5 45 18 23 38
95 59 58 95 55 82 77 62
Project Name:

Project No.:

Client Name:

Tested By: M. Vinet Date: 11/15/22
Madison Flats/Geo
13693.001
Gilbane Development Company
Boring No.

Sample No.

Container No.:

Wet Weight of Soil + Container (gm.)
Container No.:

Weight of Sample + Container (gm.)
Sample Dry Weight Determination
Depth (ft.)
Dry Weight of Soil + Container (gm.)
Moisture Correction
Sample Type
Soil Classification
Soak Time (min)
After Wash
% Retained No. 200 Sieve
Dry Weight of Sample (gm)
Dry Weight of Sample + Container (gm)
Weight of Container (gm)
Weight of Container (gm)
Moisture Content (%)
Weight of Container (gm.)
Weight of Dry Sample (gm.)
% Passing No. 200 Sieve

SM SM SM SMSP

PERCENT PASSING
No. 200 SIEVE
ASTM D 1140

SC SC SP
200 Wash (11-03-22)
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices IT-2 IT-3
S-2 S-3

13.5 47.0

SPT SPT
10 10
615.1 606.2
581.7 593.6
278.1 278.2

11.0 4.0
BL AB
581.7 593.6
278.1 278.2
303.6 315.4
BL AB
414.0 545.2
278.1 278.2
135.9 267.0
55 15
45 85
Project Name:

Project No.:

Client Name:

Tested By: M. Vinet Date: 11/15/22

PERCENT PASSING
No. 200 SIEVE
ASTM D 1140
Madison Flats/Geo
13693.001
Gilbane Development Company
Dry Weight of Sample + Container (gm)
Weight of Container (gm)
Dry Weight of Sample (gm)
% Passing No. 200 Sieve
% Retained No. 200 Sieve
Sample Dry Weight Determination
Weight of Sample + Container (gm.)
Weight of Container (gm.)
Weight of Dry Sample (gm.)
Container No.:

After Wash
Moisture Correction
Wet Weight of Soil + Container (gm.)
Dry Weight of Soil + Container (gm.)
Weight of Container (gm)
Moisture Content (%)
Container No.:

Soak Time (min)
Boring No.

Sample No.

Depth (ft.)
Sample Type
Soil Classification s(ML) SM
200 Wash (11-03-22)
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Project Name: Tested By: F. Mina Date: 11/16/22
Project No. : Input By: M. Vinet Date: 11/17/22
Boring No.: Checked By: M. Vinet
Sample No.: Depth (ft.) 5.0
Soil Identification:
1 2 1 2 3 4
15 23 35

23.53 23.59 21.89 23.04 24.99

22.42 22.44 20.30 21.34 23.00

13.74 13.81 13.66 13.80 13.67

12.79 13.33 23.95 22.55 21.33
22 13
9 CL
PI at "A" - Line = 0.73(LL-20) 1.46
One - Point Liquid Limit Calculation
LL =Wn(N/25)

PROCEDURES USED
Wet Preparation
Multipoint - Wet
X Dry Preparation
Multipoint - Dry
X Procedure A
Multipoint Test
Procedure B
One-point Test
Clayey Sand (SC), Dark Yellowish Brown.

ATTERBERG LIMITS
ASTM D 4318
13693.001
LB-2
R-2
Madison Flats/Geo
Dry Wt. of Soil + Cont. (g)
Wt. of Container (g)
Moisture Content (%) [Wn]
TEST
NO.

Liquid Limit
Plastic Limit
Plasticity Index
Classification
Number of Blows [N]
Wet Wt. of Soil + Cont. (g)

LIQUID LIMIT PLASTIC LIMIT
0 10
20 30
40 50
60 0 10 20 30 40 50 60 70 80 90 100
Plasticity Index (PI)
Liquid Limit (LL)

0.121
CL or OL
ML or OL
MH or OH
For classification of fine-
grained soils and fine-
grained fraction of coarse-
grained soils
"A" Line
7 4
CH or OH
CL- ML
19 20
21 22
23 24
25 26
10 100
Moisture Content (%)
Number of Blows
20 25 30 40 50 60 70 80 90 PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Project Name: Tested By: F. Mina Date: 11/16/22
Project No. : Input By: M. Vinet Date: 11/17/22
Boring No.: Checked By: M. Vinet
Sample No.: Depth (ft.) 7.5
Soil Identification:
1 2 1 2 3 4
15 25 35

23.40 24.81 21.51 22.21 24.26

22.16 23.31 19.78 20.38 22.11

13.69 13.69 13.69 13.60 13.78

14.64 15.59 28.41 26.99 25.81
27 15
12 CL
PI at "A" - Line = 0.73(LL-20) 5.11
One - Point Liquid Limit Calculation
LL =Wn(N/25)

PROCEDURES USED
Wet Preparation
Multipoint - Wet
X Dry Preparation
Multipoint - Dry
X Procedure A
Multipoint Test
Procedure B
One-point Test
Clayey Sand (SC), Dark Yellowish Brown.

ATTERBERG LIMITS
ASTM D 4318
13693.001
LB-3
R-3
Madison Flats/Geo
Dry Wt. of Soil + Cont. (g)
Wt. of Container (g)
Moisture Content (%) [Wn]
TEST
NO.

Liquid Limit
Plastic Limit
Plasticity Index
Classification
Number of Blows [N]
Wet Wt. of Soil + Cont. (g)

LIQUID LIMIT PLASTIC LIMIT
0 10
20 30
40 50
60 0 10 20 30 40 50 60 70 80 90 100
Plasticity Index (PI)
Liquid Limit (LL)

0.121
CL or OL
ML or OL
MH or OH
For classification of fine-
grained soils and fine-
grained fraction of coarse-
grained soils
"A" Line
7 4
CH or OH
CL- ML
23 24
25 26
27 28
29 30
31 10 100
Moisture Content (%)
Number of Blows
20 25 30 40 50 60 70 80 90 PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Project Name: Tested By: F. Mina Date: 11/16/22
Project No. : Input By: M. Vinet Date: 11/17/22
Boring No.: Checked By: M. Vinet
Sample No.: Depth (ft.) 10.0
Soil Identification:
1 2 1 2 3 4
NP
NP
NP
SM
PI at "A" - Line = 0.73(LL-20) #VALUE!
One - Point Liquid Limit Calculation
LL =Wn(N/25)

PROCEDURES USED
Wet Preparation
Multipoint - Wet
X Dry Preparation
Multipoint - Dry
X Procedure A
Multipoint Test
Procedure B
One-point Test
Silty Sand (SM), Dark Yellowish Brown.

ATTERBERG LIMITS
ASTM D 4318
13693.001
LB-6
R-4
Madison Flats/Geo
Dry Wt. of Soil + Cont. (g)
Wt. of Container (g)
Moisture Content (%) [Wn]
TEST
NO.

Liquid Limit
Plastic Limit
Plasticity Index
Classification
Number of Blows [N]
Wet Wt. of Soil + Cont. (g)

LIQUID LIMIT PLASTIC LIMIT
Non-Plastic (NP)
Non-Plastic (NP)
0 10
20 30
40 50
60 0 10 20 30 40 50 60 70 80 90 100
Plasticity Index (PI)
Liquid Limit (LL)

0.121
CL or OL
ML or OL
MH or OH
For classification of fine-
grained soils and fine-
grained fraction of coarse-
grained soils
"A" Line
7 4
CH or OH
CL- ML
23 24
25 26
27 28
29 30
31 10 100
Moisture Content (%)
Number of Blows
20 25 30 40 50 60 70 80 90 PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices

Project Name: Tested By: M. Vinet Date: 11/15/22
Project No.: Checked By: M. Vinet Date: 11/17/22
Boring No.: LB-5 Sample Type: IN SITU
Sample No.: R-2 Depth (ft.) 5.0
Sample Description:

Source and Type of Water Used for Inundation: Arrowhead ( Distilled ) ** Note: Loading After Wetting (Inundation) not Performed Using this Test Method.

Initial Dry Density (pcf): 110.9 Final Dry Density (pcf): 113.5 Initial Moisture (%): 6.1 Final Moisture (%) : 14.5
Initial Height (in.): 1.0000 Initial Void ratio: 0.5194 Initial Dial Reading (in): 0.0000 Specific Gravity (assumed): 2.70 Inside Diameter of Ring (in): 2.416 Initial Degree of Saturation (%): 31.5

0.375 0.9988 0.00 -0.12 -0.12

0.750 0.9971 0.00 -0.29 -0.29
H2O 0.9777 0.00 -2.23 -2.23

Rev. 01-10
Swell (+)
Settlement (-)
% of Sample
Thickness
One-Dimensional Swell or Settlement
Corrected
Deformation
(%)
Pressure (p)
(ksf)

0.5176

0.5150
Apparent
Thickness
(in)
Void Ratio
Madison Flats/Geo

0.0012

0.0029
Final Reading
(in)
Load
Compliance
(%)
-1.95 Percent Swell / Settlement After Inundation =
(ASTM D 4546) -- Method 'B'
Potential of Cohesive Soils

0.48550.0223
Silty Sand (SM), Dark Yellowish Brown.
13693.001
-5.00
-4.00
-3.00
-2.00
-1.00

0.00 1.00

2.00 3.00

4.00 5.00

0.010 0.100 1.000 10.000
Deformation %
Log Pressure (ksf)
Deformation % - Log Pressure Curve
Inundate With
Distilled Water
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Project Name: Tested By: M. Vinet Date: 11/14/22
Project No.: Checked By: M. Vinet Date: 11/23/22
Boring No.: Depth (ft.):

Sample No.: Sample Type:

Soil Identification:

Sample Diameter (in.): 2.415
Sample Thickness (in.): 1.000
Weight of Sample + ring (g): 189.40
Weight of Ring (g): 42.46
Height after consol. (in.): 0.9332
Wt. of Wet Sample+Cont. (g): 347.58
Wt. of Dry Sample+Cont. (g): 321.41
Weight of Container (g): 49.88
Initial Moisture Content (%) 9.6
Initial Dry Density (pcf) 111.5
Initial Saturation (%): 50
Initial Vertical Reading (in.) 0.0000
Wt. of Wet Sample+Cont. (g): 247.00
Wt. of Dry Sample+Cont. (g): 226.26
Weight of Container (g): 50.44
Final Moisture Content (%) 15.55
Final Dry Density (pcf): 118.8
Final Saturation (%): 100
Final Vertical Reading (in.) 0.0668
Specific Gravity (assumed): 2.71
Water Density (pcf): 62.43

0.10 0.0000 1.0000 0.00 0.00 0.518 0.00

0.25 0.0010 0.9990 0.00 0.10 0.516 0.10

0.50 0.0048 0.9952 0.00 0.48 0.511 0.48

1.00 0.0102 0.9898 0.00 1.02 0.502 1.02

1.00 0.0265 0.9735 0.00 2.65 0.478 2.65

2.00 0.0353 0.9647 0.00 3.53 0.464 3.53

4.00 0.0466 0.9534 0.00 4.66 0.447 4.66

8.00 0.0638 0.9362 0.00 6.38 0.421 6.38

16.00 0.0845 0.9155 0.00 8.45 0.390 8.45

4.00 0.0819 0.9181 0.00 8.19 0.394 8.19

1.00 0.0742 0.9258 0.00 7.42 0.405 7.42

0.25 0.0668 0.9332 0.00 6.68 0.416 6.68

ONE-DIMENSIONAL CONSOLIDATION
ASTM D 2435
13693.001
Madison Flats/Geo
Deformation
% of Sample
Thickness Square
Root of
Time
Final
Reading
(in.)
Apparent
Thickness
(in.)
Load
Compliance
(%)
PROPERTIES of SOILS
Ring
Void
Ratio
Sandy Silt s(ML), Brown.

No Time Readings Taken
Elapsed
Time (min)

5.0 Pressure
(p)
(ksf) Dial Rdgs.
(in.)Date
LB-3
R-2
Time
Corrected
Deforma-
tion (%)
Before Test
After Test

0.370

0.390

0.410

0.430

0.450

0.470

0.490

0.510

0.530

0.10 1.00 10.00 100.00
Void Ratio
Pressure, p (ksf)
Inundate with
Tap water
Consolidation; LB-3, R-2 (11-03-22)
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Initial Final Initial Final Initial Final Initial Final Soil Identification:

Boring
No.

Sample
No.

Depth
(ft.)
Moisture
Content (%)

ONE-DIMENSIONAL CONSOLIDATION
PROPERTIES of SOILS
ASTM D 2435

15.6 118.8LB-3 R-2 9.6
Sandy Silt s(ML), Brown.

Project No.:

Madison Flats/Geo
11-22
13693.001
No Time Readings Taken

0.416 50 100111.5
Degree of
Saturation (%)Dry Density (pcf)

0.518
Void Ratio
5 0.0000

0.1000

0.2000

0.3000

0.4000

0.5000

0.6000

0.7000

0.8000

0.9000

1.0000

0.1 1.0
Deformation Dial Reading (in.)
Log of Time (min.)

0.00 1.00

2.00 3.00

4.00 5.00

6.00 7.00

8.00 9.00

0.10 1.00 10.00 100.00
Deformation (%)
Pressure, p (ksf)

0.0000

0.2000

0.4000

0.6000

0.8000

1.0000

1.2000

0.0 10.0
Square Root of Time (min.1/2)
Inundate with
Tap water
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Project Name: Tested By: M. Vinet Date: 11/16/22
Project No. : Checked By: M. Vinet Date: 11/17/22
Boring No.: Depth: 0 - 5.0
Sample No. : Location:

Sample Description:

Dry Wt. of Soil + Cont. (gm.)
Wt. of Container No. (gm.)
Dry Wt. of Soil (gm.)
Weight Soil Retained on #4 Sieve
Percent Passing # 4
in distilled water for the period of 24 h or expansion rate < 0.0002 in./h.

Rev. 03-08

0.508211/17/22
0 1295
Expansion Index (EI meas) = ((Final Rdg - Initial Rdg) / Initial Thick.) x 1000 8:00
1355 0.5082

8.2 1.0
8 Expansion Index ( Report ) = Nearest Whole Number or Zero (0) if Initial Height is > than Final Height Add Distilled Water to the Specimen
Wt. of Container (gm.)
115.7

0.5000
10 0.5000
11/17/22 9:00

1.0 1.0
10:25 1.011/16/22
11/16/22
116.7
Moisture Content (%)
Date
10:15
Void Ratio
Pore Volume (cc)
Degree of Saturation (%) [ S meas]
126.6
Time
After TestBefore Test
Wet Wt. of Soil + Cont. (gm.)
7 0.457
Dry Density (pcf)
Wet Density (pcf)
Specific Gravity (Assumed)
Specimen Height (in.)
Wt. of Mold (gm.)

97.7 4.01

2.70 3522.2

0.0 597.4
3522.2

80.2 1.0082
619.6
N/A
Madison Flats/Geo
13693.001
LB-6
B-1
ASTM D 4829
EXPANSION INDEX of SOILS
Sandy Silt s(ML), Dark Reddish Brown.

MOLDED SPECIMEN

4.01 1.0000
7Container No.

Specimen Diameter (in.)
Wt. Comp. Soil + Mold (gm.)
177.7

2.70 386.8
177.7

14.2 0.313

65.4 177.7
619.6
132.2
Elapsed Time
(min.)
Dial Readings
(in.)

84.251.6
Pressure
(psi)

0.308Total Porosity

SPECIMEN INUNDATION

63.7 Dry Wt. of Soil + Cont. (gm.)

8.5 629.3
605.8

0.445
329.3
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Project Name: Tested By : M. Vinet Date: 11/17/22
Project No. : 13693.001 Data Input By: M. Vinet Date: 11/17/22 Boring No. LB-3
Sample No. B-1
Sample Depth (ft) 0 - 5.0
100.0
100.0

0.0 0.0
100.0
Dilution : 1 3
Water Fraction (ml) 25
Tube Reading 60
PPM Sulfate 180
% Sulfate 0.0180
ml of Extract For Titration (B) 30
ml of AgNO3 Soln. Used in Titration (C) 0.6
PPM of Chloride (C -0.2) * 100 * 30 / B 40
PPM of Chloride, Dry Wt. Basis 40

7.60 21.0
pH Value
Temperature °C
pH TEST, DOT California Test 643
SULFATE CONTENT, Hach Kit Method
Weight of Container (g)
CHLORIDE CONTENT, DOT California Test 422
Moisture Content (%)
Madison Flats/Geo
Weight of Soaked Soil (g)
Soil Identification: Silty Sand (SM)
TESTS for SULFATE CONTENT
CHLORIDE CONTENT and pH of SOILS
Wet Weight of Soil + Container (g)
Dry Weight of Soil + Container (g)
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Project Name: Tested By : Date:

Project No. : Data Input By: M. Vinet Date:

Boring No.: Depth (ft.) :

Sample No. : B-1
Container No.

Initial Soil Wt. (g) (Wt)
Box Constant1200 1200
Silty Sand (SM)
Resistance
Reading
(ohm)

16.60 Soil
Resistivity
(ohm-cm)
Madison Flats/Geo 11/17/22
11/17/22
0 - 5.0
13693.001
LB-3
M. Vinet

SOIL RESISTIVITY TEST
DOT CA TEST 643
Temp. (°C)pH
Soil pH
1300
1100
100.00

0.00 MC =(((1+Mci/100)x(Wa/Wt+1))-1)x100
1100 23.2 180 40 7.60 21.0
4 83
116
149
A
500.003 110023.20
1300
Min. Resistivity
DOT CA Test 643Hach Kit DOT CA Test 422
(%) (ppm) (ppm)
DOT CA Test 643

1.000
Chloride Content
(ohm-cm)

29.80 Moisture Content Sulfate Content
5 1
2 Water
Added (ml)
(Wa)
50 Adjusted
Moisture
Content
(MC) Dry Wt. of Soil + Cont. (g)
2400
Soil Identification:*
*California Test 643 requires soil specimens to consist only of portions of samples passing through the No. 8 US Standard Sieve before resistivity testing.  Therefore, this test method may not be representative for coarser materials.

Wt. of Container (g)10.00 2400

0.00 100.00
Moisture Content (%) (MCi)
Wet Wt. of Soil + Cont. (g)
Specimen
No.
0 500
1000
1500
2000
2500
3000

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0
Soil Resistivity (ohm-cm)
Moisture Content (%)
Minimum resistivity
read here
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Project Name: Date: 6/15/22
Project Number: 13693.001 Technician: F. Mina
Boring Number: LB-6 Depth (ft.): 0 - 5.0
Sample Number: B-1
Sample Description:

TEST SPECIMEN A B C
MOISTURE AT COMPACTION % 8.7 10.3 11.4
HEIGHT OF SAMPLE, Inches 2.54 2.55 2.50
DRY DENSITY, pcf 118.7 117.8 114.1
COMPACTOR AIR PRESSURE, psi 200 175 150
EXUDATION PRESSURE, psi 574 309 203
EXPANSION, Inches x 10exp-4 0 0 0
STABILITY Ph 2,000 lbs (160 psi) 35 71 110
TURNS DISPLACEMENT 4.90 5.72 5.95
R-VALUE UNCORRECTED 65 35 16
R-VALUE CORRECTED 65 35 16
DESIGN CALCULATION DATA a b c
GRAVEL EQUIVALENT FACTOR 1.0 1.0 1.0
TRAFFIC INDEX 5.0 5.0 5.0
STABILOMETER THICKNESS, ft. 0.57 1.03 1.34
EXPANSION PRESSURE THICKNESS, ft. 0.00 0.00 0.00

EXPANSION PRESSURE CHART EXUDATION PRESSURE CHART R-VALUE BY EXPANSION: N/A
R-VALUE BY EXUDATION: 35
EQUILIBRIUM R-VALUE: 35

R-VALUE TEST RESULTS
ASTM D 2844
Madison Flats/Geo
Sandy Silt s(ML), Dark Reddish Brown. N/ASample Location:

0.00 0.50

1.00 1.50

2.00 2.50

3.00 3.50

4.00 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00
COVER THICKNESS BY EXPANSION in
feet
COVER THICKNESS BY STABILOMETER in
feet
0 10
20 30
40 50
60 70
80 90
0100200300400500600700800

R-VALUE
EXUDATION PRESSURE (psi)
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices

APPENDIX D

SUMMARY OF

SEISMIC ANALYSIS
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Latitude, Longitude: 33.932279, -117.405463
Date 11/7/2022, 10:16:24 AM
Design Code Reference Document ASCE7-16
Risk Category II
Site Class D - Stiff Soil
Type Value Description
SS 1.5 MCER ground motion. (for 0.2 second period)
S1 0.572 MCER ground motion. (for 1.0s period)
SMS 1.5 Site-modified spectral acceleration value
SM1 null -See Section 11.4.8 Site-modified spectral acceleration value SDS 1 Numeric seismic design value at 0.2 second SA
SD1 null -See Section 11.4.8 Numeric seismic design value at 1.0 second SA Type Value Description
SDC null -See Section 11.4.8 Seismic design category
Fa 1 Site amplification factor at 0.2 second
Fv null -See Section 11.4.8 Site amplification factor at 1.0 second PGA 0.5 MCEG peak ground acceleration
FPGA 1.1 Site amplification factor at PGA
PGAM 0.55 Site modified peak ground acceleration
TL 8 Long-period transition period in seconds
SsRT 1.565 Probabilistic risk-targeted ground motion. (0.2 second) SsUH 1.656 Factored uniform-hazard (2% probability of exceedance in 50 years) spectral acceleration SsD 1.5 Factored deterministic acceleration value. (0.2 second) S1RT 0.572 Probabilistic risk-targeted ground motion. (1.0 second) S1UH 0.622 Factored uniform-hazard (2% probability of exceedance in 50 years) spectral acceleration.

S1D 0.6 Factored deterministic acceleration value. (1.0 second) PGAd 0.5 Factored deterministic acceleration value. (Peak Ground Acceleration) PGAUH 0.648 Uniform-hazard (2% probability of exceedance in 50 years) Peak Ground Acceleration CRS 0.945 Mapped value of the risk coefficient at short periods CR1 0.92 Mapped value of the risk coefficient at a period of 1 s CV 1.4 Vertical coefficient
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices

DISCLAIMER
While the information presented on this website is believed to be correct, SEAOC /OSHPD and its sponsors and contributors assume no responsibility or liability for its accuracy. The material presented in this web application should not be used or relied upon for any specific application without competent examination and verification of its accuracy, suitability and applicability by engineers or other licensed professionals. SEAOC / OSHPD do not intend that the use of this information replace the sound judgment of such competent professionals, having experience and knowledge in the field of practice, nor to substitute for the standard of care required of such professionals in interpreting and applying the results of the seismic data provided by this website. Users of the information from this website assume all liability arising from such use. Use of the output of this website does not imply approval by the governing building code bodies responsible for building code approval and interpretation for the building site described by latitude/longitude location in the search results of this website.

PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Liquefaction Susceptibility Analysis: SPT Method Leighton Youd and Idriss (2001), Martin and Lew (1999)
Description: Madison Flats - Riverside ; Case 1; PGAm 0.55; design GW 82; No overex 0 Project No.: 13693.001
Nov 2022
General Boring Information:

Existing Design Design Overex. Ground design Boring Location General Parameters:

Boring GW GW Fill Height depth bgs Surface gw Coordinates amax = 0.55g No. Depth (ft) Depth (ft) (ft) (ft) Elev (ft) elve X (ft) Y (ft) MW = 8.1 LB-1 91 82 0 861 779 163.77 209.61 MSF eq: 1
LB-2 91 82 0 862 780 370.95 384.13 MSF = 0.82
LB-3 91 82 0 861 779 634.46 612.69 Hammer Efficiency = 84 LB-4 91 82 0 857 775 783.36 756.48 CE = 1.40
LB-5 91 82 0 857 775 1031.9 962.3 CB = 1
LB-6 91 82 0 858 776 1117.5 1042.1 CS for SPT? TRUE
LB-7 91 82 0 858 776 1231.4 1108.7 Unlined, but room for liner 0 Rod Stickup (feet) = 3
0 Ring sample correction = 0.65
0 0
0 0
0 0
0 0
Leighton Page 1 of 1
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Summary of Liquefaction Susceptibility Analysis: SPT Method Leighton Liquefaction Method: Youd and Idriss (2001). Seismic Settlement Method: Tokimatsu and Seed (1987) and Martin and Lew (1999).

Project: Madison Flats - Riverside ; Case 1; PGAm 0.55; design GW 82; No overex 0 Project No.: 13693.001
Boring
No.

Approx. Layer
Depth
SPT
Depth
Approx
Layer
Thick-
ness
Plasticity
("n"=non
susc. to
liq.)
Estimated
Fines Cont t
Nm
or B
Sampler
Type
(enter 2 if
mod CA
Ring) Cs
Nm
(corrected
for Cs and
ring->SPT)
Exist
vo'( N 1)60 (N1)60CS CRR7.5
Design
vo' CSR 7.5 CSRM
Liquefaction
Factor of
Safety
(N1)60CS
(for Settle-
ment)
Dry Sand
Strain (%)
(Tok/ Seed
87)
Sat Sand
Strain (%)
(Tok/ Seed
87)
Seismic
Sett. of
Layer
Cummulative
Seismic
Settlement
(ft) (ft) (ft) (%) (pcf) (blows/ft) (blows/ft) (psf) (psf) (blows/ft) (%) (%) (in.) (in.) LB-1 0 to 3.8 2.5 3.8 45 120 12 2 1 7.8 300 13.9 21.7 0.238 300 0.36 0.43 NonLiq 21.7 0.06 0.03 0.8 LB-1 3.8 to 6.3 5 2.5 35 120 13 2 1 8.5 600 15.1 23.1 0.259 600 0.35 0.43 NonLiq 23.1 0.18 0.05 0.8 LB-1 6.3 to 8.8 7.5 2.5 35 120 21 2 1 13.7 900 23.3 32.9 >Range 900 0.35 0.43 NonLiq 32.9 0.05 0.01 0.7 LB-1 8.8 to 12.5 10 3.8 30 120 21 2 1 13.7 1200 21.4 29.4 0.433 1200 0.35 0.43 NonLiq 29.4 0.15 0.07 0.7 LB-1 12.5 to 17.5 15 5.0 5 120 11 1 1.16 12.8 1800 16.4 16.4 0.175 1800 0.34 0.42 NonLiq 16.4 0.32 0.19 0.6 LB-1 17.5 to 22.5 20 5.0 15 120 42 2 1 27.3 2400 33.9 38.0 >Range 2400 0.34 0. 42 NonLiq 38.0 0.08 0.05 0.5 LB-1 22.5 to 27.5 25 5.0 70 120 25 1 1.3 32.5 3000 36.1 48.3 >Range 3000 0.34 0.41 NonLiq 48.3 0.03 0.02 0.4 LB-1 27.5 to 32.5 30 5.0 80 120 38 2 1 24.7 3600 26.3 36.6 >Range 3600 0.33 0. 41 NonLiq 36.6 0.07 0.04 0.4 LB-1 32.5 to 37.5 35 5.0 80 120 11 1 1.12 12.3 4200 12.2 19.6 0.211 4200 0.32 0.39 NonLiq 19.6 0.36 0.22 0.3 LB-1 37.5 to 42.5 40 5.0 70 120 29 2 1 18.9 4800 17.4 25.9 0.311 4800 0.30 0.37 NonLiq 25.9 0.19 0.11 0.1 LB-1 42.5 to 47.5 45 5.0 40 120 100 1 1.3 130.0 5400 113.2 140.8 >Range 5400 0.29 0.35 NonLiq 140.8 0.01 0.01 0.0 LB-1 47.5 to 52.0 50 4.5 20 120 100 2 1 65.0 6000 53.7 61.6 >Range 6000 0.27 0 .33 NonLiq 61.6 0.02 0.01 0.0 LB-2 0 to 3.8 2.5 3.8 45 120 17 2 1 11.1 300 19.7 28.7 0.395 300 0.36 0.43 NonLiq 28.7 0.05 0.02 0.3 LB-2 3.8 to 6.3 5 2.5 41 120 13 2 1 8.5 600 15.1 23.1 0.259 600 0.35 0.43 NonLiq 23.1 0.18 0.05 0.3 LB-2 6.3 to 8.8 7.5 2.5 45 120 16 2 1 10.4 900 17.7 26.3 0.320 900 0.35 0.43 NonLiq 26.3 0.10 0.03 0.2 LB-2 8.8 to 12.5 10 3.8 45 120 26 2 1 16.9 1200 26.5 36.8 >Range 1200 0.35 0.43 NonLiq 36.8 0.06 0.03 0.2 LB-2 12.5 to 17.5 15 5.0 40 120 11 1 1.16 12.8 1800 16.4 24.7 0.286 1800 0.34 0.42 NonLiq 24.7 0.14 0.08 0.2 LB-2 17.5 to 22.0 20 4.5 30 120 26 2 1 16.9 2400 21.0 28.9 0.406 2400 0.34 0.42 NonLiq 28.9 0.17 0.09 0.1 LB-3 0 to 3.8 2.5 3.8 40 120 15 2 1 9.8 300 17.4 25.9 0.310 300 0.36 0.43 NonLiq 25.9 0.05 0.02 0.5 LB-3 3.8 to 6.3 5 2.5 85 120 15 2 1 9.8 600 17.4 25.9 0.310 600 0.35 0.43 NonLiq 25.9 0.16 0.05 0.5 LB-3 6.3 to 8.8 7.5 2.5 42 120 19 2 1 12.4 900 21.1 30.3 >Range 900 0.35 0.43 NonLiq 30.3 0.05 0.02 0.5 LB-3 8.8 to 12.5 10 3.8 75 120 21 2 1 13.7 1200 21.4 30.7 >Range 1200 0.35 0.43 NonLiq 30.7 0.08 0.04 0.4 LB-3 12.5 to 17.5 15 5.0 5 120 13 1 1.2 15.6 1800 20.0 20.0 0.215 1800 0.34 0.42 NonLiq 20.0 0.27 0.16 0.4 LB-3 17.5 to 22.5 20 5.0 45 120 32 2 1 20.8 2400 25.8 36.0 >Range 2400 0.34 0. 42 NonLiq 36.0 0.08 0.05 0.2 LB-3 22.5 to 27.5 25 5.0 90 120 19 1 1.27 24.1 3000 26.7 37.0 >Range 3000 0.3 40 . 4 1 NonLiq 37.0 0.10 0.06 0.2 LB-3 27.5 to 32.5 30 5.0 90 120 36 2 1 23.4 3600 24.9 34.9 >Range 3600 0.33 0. 41 NonLiq 34.9 0.08 0.05 0.1 LB-3 32.5 to 37.5 35 5.0 80 120 22 1 1.28 28.1 4200 27.7 38.3 >Range 4200 0.3 20 . 3 9 NonLiq 38.3 0.08 0.05 0.1 LB-3 37.5 to 42.5 40 5.0 30 120 100 2 1 65.0 4800 60.0 74.0 >Range 4800 0.30 0 .37 NonLiq 74.0 0.02 0.01 0.0 LB-3 42.5 to 47.5 45 5.0 35 120 29 1 1.3 37.7 5400 32.8 44.4 >Range 5400 0.29 0.35 NonLiq 44.4 0.02 0.01 0.0 LB-3 47.5 to 52.0 50 4.5 60 120 60 2 1 39.0 6000 32.2 43.7 >Range 6000 0.27 0. 33 NonLiq 43.7 0.03 0.01 0.0 LB-4 0 to 3.8 2.5 3.8 65 120 9 2 1 5.9 300 10.4 17.5 0.187 300 0.36 0.43 NonLiq 17.5 0.12 0.05 0.3 LB-4 3.8 to 6.3 5 2.5 30 120 17 2 1 11.1 600 19.7 27.5 0.352 600 0.35 0.43 NonLiq 27.5 0.14 0.04 0.2 LB-4 6.3 to 8.8 7.5 2.5 35 120 32 2 1 20.8 900 35.5 47.6 >Range 900 0.35 0.43 NonLiq 47.6 0.01 0.00 0.2 LB-4 8.8 to 12.5 10 3.8 30 120 19 2 1 12.4 1200 19.4 27.1 0.341 1200 0.35 0.43 NonLiq 27.1 0.16 0.07 0.2 Leighton Page 1 of 2
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Boring
No.

Approx. Layer
Depth
SPT
Depth
Approx
Layer
Thick-
ness
Plasticity
("n"=non
susc. to
liq.)
Estimated
Fines Cont t
Nm
or B
Sampler
Type
(enter 2 if
mod CA
Ring) Cs
Nm
(corrected
for Cs and
ring->SPT)
Exist
vo'( N 1)60 (N1)60CS CRR7.5
Design
vo' CSR 7.5 CSRM
Liquefaction
Factor of
Safety
(N1)60CS
(for Settle-
ment)
Dry Sand
Strain (%)
(Tok/ Seed
87)
Sat Sand
Strain (%)
(Tok/ Seed
87)
Seismic
Sett. of
Layer
Cummulative
Seismic
Settlement
(ft) (ft) (ft) (%) (pcf) (blows/ft) (blows/ft) (psf) (psf) (blows/ft) (%) (%) (in.) (in.) LB-4 12.5 to 17.5 15 5.0 80 120 16 1 1.26 20.1 1800 25.8 35.9 >Range 1800 0.3 40 . 4 2 NonLiq 35.9 0.06 0.04 0.1 LB-4 17.5 to 22.0 20 4.5 45 120 34 2 1 22.1 2400 27.4 37.9 >Range 2400 0.34 0. 42 NonLiq 37.9 0.08 0.04 0.0 LB-5 0 to 3.8 2.5 3.8 85 120 19 2 1 12.4 300 22.0 31.5 >Range 300 0.36 0.43 NonLiq 31.5 0.02 0.01 0.2 LB-5 3.8 to 6.3 5 2.5 30 120 25 2 1 16.3 600 29.0 38.2 >Range 600 0.35 0.43 NonLiq 38.2 0.05 0.02 0.2 LB-5 6.3 to 8.8 7.5 2.5 15 120 22 2 1 14.3 900 24.4 28.1 0.372 900 0.35 0.43 NonLiq 28.1 0.10 0.03 0.2 LB-5 8.8 to 12.5 10 3.8 70 120 20 2 1 13.0 1200 20.4 29.5 0.435 1200 0.35 0.43 NonLiq 29.5 0.15 0.07 0.2 LB-5 12.5 to 17.5 15 5.0 85 120 11 1 1.16 12.8 1800 16.4 24.7 0.286 1800 0.34 0.42 NonLiq 24.7 0.14 0.08 0.1 LB-5 17.5 to 22.0 20 4.5 85 120 33 2 1 21.5 2400 26.6 36.9 >Range 2400 0.34 0. 42 NonLiq 36.9 0.08 0.04 0.0 LB-6 0 to 3.8 2.5 3.8 90 120 30 2 1 19.5 300 34.8 46.8 >Range 300 0.36 0.43 NonLiq 46.8 0.01 0.00 0.2 LB-6 3.8 to 6.3 5 2.5 30 120 27 2 1 17.6 600 31.3 40.9 >Range 600 0.35 0.43 NonLiq 40.9 0.02 0.00 0.2 LB-6 6.3 to 8.8 7.5 2.5 40 120 21 2 1 13.7 900 23.3 32.9 >Range 900 0.35 0.43 NonLiq 32.9 0.05 0.01 0.2 LB-6 8.8 to 12.5 10 3.8 45 120 49 2 1 31.9 1200 50.0 65.0 >Range 1200 0.35 0.43 NonLiq 65.0 0.01 0.01 0.2 LB-6 12.5 to 17.5 15 5.0 75 120 18 1 1.3 23.4 1800 30.0 41.0 >Range 1800 0.34 0.42 NonLiq 41.0 0.02 0.01 0.2 LB-6 17.5 to 22.5 20 5.0 90 120 38 2 1 24.7 2400 30.6 41.8 >Range 2400 0.34 0. 42 NonLiq 41.8 0.02 0.01 0.2 LB-6 22.5 to 27.5 25 5.0 40 120 17 1 1.23 20.9 3000 23.2 32.9 >Range 3000 0.3 40 . 4 1 NonLiq 32.9 0.11 0.07 0.1 LB-6 27.5 to 32.5 30 5.0 80 120 54 2 1 35.1 3600 37.4 49.9 >Range 3600 0.33 0. 41 NonLiq 49.9 0.02 0.01 0.1 LB-6 32.5 to 37.5 35 5.0 20 120 27 1 1.3 35.1 4200 34.6 41.0 >Range 4200 0.32 0.39 NonLiq 41.0 0.02 0.01 0.1 LB-6 37.5 to 42.5 40 5.0 15 120 66 2 1 42.9 4800 39.6 44.0 >Range 4800 0.30 0. 37 NonLiq 44.0 0.02 0.01 0.0 LB-6 42.5 to 47.5 45 5.0 15 120 40 1 1.3 52.0 5400 45.3 49.9 >Range 5400 0.29 0.35 NonLiq 49.9 0.02 0.01 0.0 LB-6 47.5 to 52.0 50 4.5 10 120 84 2 1 54.6 6000 45.1 46.9 >Range 6000 0.27 0. 33 NonLiq 46.9 0.02 0.01 0.0 LB-7 0 to 3.8 2.5 3.8 60 120 27 2 1 17.6 300 31.3 42.6 >Range 300 0.36 0.43 NonLiq 42.6 0.01 0.00 1.1 LB-7 3.8 to 6.3 5 2.5 18 120 6 2 1 3.9 600 7.0 10.7 0.119 600 0.35 0.43 NonLiq 10.7 1.52 0.46 1.1 LB-7 6.3 to 8.8 7.5 2.5 70 120 19 2 1 12.4 900 21.1 30.3 >Range 900 0.35 0.43 NonLiq 30.3 0.05 0.02 0.6 LB-7 8.8 to 12.5 10 3.8 85 120 51 2 1 33.2 1200 52.0 67.4 >Range 1200 0.35 0.43 NonLiq 67.4 0.01 0.01 0.6 LB-7 12.5 to 17.5 15 5.0 30 120 14 1 1.22 17.1 1800 21.9 29.9 0.463 1800 0.34 0.42 NonLiq 29.9 0.12 0.07 0.6 LB-7 17.5 to 22.0 20 4.5 5 120 17 2 1 11.1 2400 13.7 13.7 0.147 2400 0.34 0.42 NonLiq 13.7 0.98 0.53 0.5 Leighton Page 2 of 2
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Liquefaction Susceptibility Analysis: SPT Method Leighton Youd and Idriss (2001), Martin and Lew (1999)
Description: Madison Flats - Riverside ; Case 3; PGAm 0.55; design GW 82; Overex./scarify 5 Project No.: 13693.001
Nov 2022
General Boring Information:

Existing Design Design Overex. Ground design Boring Location General Parameters:

Boring GW GW Fill Height depth bgs Surface gw Coordinates amax = 0.55g No. Depth (ft) Depth (ft) (ft) (ft) Elev (ft) elve X (ft) Y (ft) MW = 8.1 LB-1 91 82 5 861 779 163.77 209.61 MSF eq: 1
LB-2 91 82 5 862 780 370.95 384.13 MSF = 0.82
LB-3 91 82 5 861 779 634.46 612.69 Hammer Efficiency = 84 LB-4 91 82 5 857 775 783.36 756.48 CE = 1.40
LB-5 91 82 5 857 775 1031.9 962.3 CB = 1
LB-6 91 82 5 858 776 1117.5 1042.1 CS for SPT? TRUE
LB-7 91 82 5 858 776 1231.4 1108.7 Unlined, but room for liner 0 Rod Stickup (feet) = 3
0 Ring sample correction = 0.65
0 0
0 0
0 0
0 0
Leighton Page 1 of 1
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Summary of Liquefaction Susceptibility Analysis: SPT Method Leighton Liquefaction Method: Youd and Idriss (2001). Seismic Settlement Method: Tokimatsu and Seed (1987) and Martin and Lew (1999).

Project: Madison Flats - Riverside ; Case 3; PGAm 0.55; design GW 82; Overex./scarify 5 Project No.: 13693.001
Boring
No.

Approx. Layer
Depth
SPT
Depth
Approx
Layer
Thick-
ness
Plasticity
("n"=non
susc. to
liq.)
Estimated
Fines Cont t
Nm
or B
Sampler
Type
(enter 2 if
mod CA
Ring) Cs
Nm
(corrected
for Cs and
ring->SPT)
Exist
vo'( N 1)60 (N1)60CS CRR7.5
Design
vo' CSR 7.5 CSRM
Liquefaction
Factor of
Safety
(N1)60CS
(for Settle-
ment)
Dry Sand
Strain (%)
(Tok/ Seed
87)
Sat Sand
Strain (%)
(Tok/ Seed
87)
Seismic
Sett. of
Layer
Cummulative
Seismic
Settlement
(ft) (ft) (ft) (%) (pcf) (blows/ft) (blows/ft) (psf) (psf) (blows/ft) (%) (%) (in.) (in.) LB-1 0 to 3.8 2.5 3.8 OX 45 120 50 1 1.3 65.0 300 116.0 144.2 >Range 300 0.36 0.43 NonLiq 144.2 0.00 0.00 0.8 LB-1 3.8 to 5.0 5 1.3 OX 35 120 50 1 1.3 65.0 600 116.0 144.2 >Range 600 0.35 0.43 NonLiq 144.2 0.00 0.00 0.8 LB-1 5.0 to 6.3 5 1.3 35 120 13 2 1 8.5 600 15.1 23.1 0.259 600 0.35 0.43 NonLiq 23.1 0.18 0.03 0.8 LB-1 6.3 to 8.8 7.5 2.5 35 120 21 2 1 13.7 900 23.3 32.9 >Range 900 0.35 0.43 NonLiq 32.9 0.05 0.01 0.7 LB-1 8.8 to 12.5 10 3.8 30 120 21 2 1 13.7 1200 21.4 29.4 0.433 1200 0.35 0.43 NonLiq 29.4 0.15 0.07 0.7 LB-1 12.5 to 17.5 15 5.0 5 120 11 1 1.16 12.8 1800 16.4 16.4 0.175 1800 0.34 0.42 NonLiq 16.4 0.32 0.19 0.6 LB-1 17.5 to 22.5 20 5.0 15 120 42 2 1 27.3 2400 33.9 38.0 >Range 2400 0.34 0. 42 NonLiq 38.0 0.08 0.05 0.5 LB-1 22.5 to 27.5 25 5.0 70 120 25 1 1.3 32.5 3000 36.1 48.3 >Range 3000 0.34 0.41 NonLiq 48.3 0.03 0.02 0.4 LB-1 27.5 to 32.5 30 5.0 80 120 38 2 1 24.7 3600 26.3 36.6 >Range 3600 0.33 0. 41 NonLiq 36.6 0.07 0.04 0.4 LB-1 32.5 to 37.5 35 5.0 80 120 11 1 1.12 12.3 4200 12.2 19.6 0.211 4200 0.32 0.39 NonLiq 19.6 0.36 0.22 0.3 LB-1 37.5 to 42.5 40 5.0 70 120 29 2 1 18.9 4800 17.4 25.9 0.311 4800 0.30 0.37 NonLiq 25.9 0.19 0.11 0.1 LB-1 42.5 to 47.5 45 5.0 40 120 100 1 1.3 130.0 5400 113.2 140.8 >Range 5400 0.29 0.35 NonLiq 140.8 0.01 0.01 0.0 LB-1 47.5 to 52.0 50 4.5 20 120 100 2 1 65.0 6000 53.7 61.6 >Range 6000 0.27 0 .33 NonLiq 61.6 0.02 0.01 0.0 LB-2 0 to 3.8 2.5 3.8 OX 45 120 50 1 1.3 65.0 300 116.0 144.2 >Range 300 0.36 0.43 NonLiq 144.2 0.00 0.00 0.3 LB-2 3.8 to 5.0 5 1.3 OX 41 120 50 1 1.3 65.0 600 116.0 144.2 >Range 600 0.35 0.43 NonLiq 144.2 0.00 0.00 0.3 LB-2 5.0 to 6.3 5 1.3 41 120 13 2 1 8.5 600 15.1 23.1 0.259 600 0.35 0.43 NonLiq 23.1 0.18 0.03 0.3 LB-2 6.3 to 8.8 7.5 2.5 45 120 16 2 1 10.4 900 17.7 26.3 0.320 900 0.35 0.43 NonLiq 26.3 0.10 0.03 0.2 LB-2 8.8 to 12.5 10 3.8 45 120 26 2 1 16.9 1200 26.5 36.8 >Range 1200 0.35 0.43 NonLiq 36.8 0.06 0.03 0.2 LB-2 12.5 to 17.5 15 5.0 40 120 11 1 1.16 12.8 1800 16.4 24.7 0.286 1800 0.34 0.42 NonLiq 24.7 0.14 0.08 0.2 LB-2 17.5 to 22.0 20 4.5 30 120 26 2 1 16.9 2400 21.0 28.9 0.406 2400 0.34 0.42 NonLiq 28.9 0.17 0.09 0.1 LB-3 0 to 3.8 2.5 3.8 OX 40 120 50 1 1.3 65.0 300 116.0 144.2 >Range 300 0.36 0.43 NonLiq 144.2 0.00 0.00 0.5 LB-3 3.8 to 5.0 5 1.3 OX 85 120 50 1 1.3 65.0 600 116.0 144.2 >Range 600 0.35 0.43 NonLiq 144.2 0.00 0.00 0.5 LB-3 5.0 to 6.3 5 1.3 85 120 15 2 1 9.8 600 17.4 25.9 0.310 600 0.35 0.43 NonLiq 25.9 0.16 0.02 0.5 LB-3 6.3 to 8.8 7.5 2.5 42 120 19 2 1 12.4 900 21.1 30.3 >Range 900 0.35 0.43 NonLiq 30.3 0.05 0.02 0.5 LB-3 8.8 to 12.5 10 3.8 75 120 21 2 1 13.7 1200 21.4 30.7 >Range 1200 0.35 0.43 NonLiq 30.7 0.08 0.04 0.4 LB-3 12.5 to 17.5 15 5.0 5 120 13 1 1.2 15.6 1800 20.0 20.0 0.215 1800 0.34 0.42 NonLiq 20.0 0.27 0.16 0.4 LB-3 17.5 to 22.5 20 5.0 45 120 32 2 1 20.8 2400 25.8 36.0 >Range 2400 0.34 0. 42 NonLiq 36.0 0.08 0.05 0.2 LB-3 22.5 to 27.5 25 5.0 90 120 19 1 1.27 24.1 3000 26.7 37.0 >Range 3000 0.3 40 . 4 1 NonLiq 37.0 0.10 0.06 0.2 LB-3 27.5 to 32.5 30 5.0 90 120 36 2 1 23.4 3600 24.9 34.9 >Range 3600 0.33 0. 41 NonLiq 34.9 0.08 0.05 0.1 LB-3 32.5 to 37.5 35 5.0 80 120 22 1 1.28 28.1 4200 27.7 38.3 >Range 4200 0.3 20 . 3 9 NonLiq 38.3 0.08 0.05 0.1 LB-3 37.5 to 42.5 40 5.0 30 120 100 2 1 65.0 4800 60.0 74.0 >Range 4800 0.30 0 .37 NonLiq 74.0 0.02 0.01 0.0 LB-3 42.5 to 47.5 45 5.0 35 120 29 1 1.3 37.7 5400 32.8 44.4 >Range 5400 0.29 0.35 NonLiq 44.4 0.02 0.01 0.0 LB-3 47.5 to 52.0 50 4.5 60 120 60 2 1 39.0 6000 32.2 43.7 >Range 6000 0.27 0. 33 NonLiq 43.7 0.03 0.01 0.0 LB-4 0 to 3.8 2.5 3.8 OX 65 120 50 1 1.3 65.0 300 116.0 144.2 >Range 300 0.36 0.43 NonLiq 144.2 0.00 0.00 0.2 Leighton Page 1 of 2
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices Boring
No.

Approx. Layer
Depth
SPT
Depth
Approx
Layer
Thick-
ness
Plasticity
("n"=non
susc. to
liq.)
Estimated
Fines Cont t
Nm
or B
Sampler
Type
(enter 2 if
mod CA
Ring) Cs
Nm
(corrected
for Cs and
ring->SPT)
Exist
vo'( N 1)60 (N1)60CS CRR7.5
Design
vo' CSR 7.5 CSRM
Liquefaction
Factor of
Safety
(N1)60CS
(for Settle-
ment)
Dry Sand
Strain (%)
(Tok/ Seed
87)
Sat Sand
Strain (%)
(Tok/ Seed
87)
Seismic
Sett. of
Layer
Cummulative
Seismic
Settlement
(ft) (ft) (ft) (%) (pcf) (blows/ft) (blows/ft) (psf) (psf) (blows/ft) (%) (%) (in.) (in.) LB-4 3.8 to 5.0 5 1.3 OX 30 120 50 1 1.3 65.0 600 116.0 138.6 >Range 600 0.35 0.43 NonLiq 138.6 0.00 0.00 0.2 LB-4 5.0 to 6.3 5 1.3 30 120 17 2 1 11.1 600 19.7 27.5 0.352 600 0.35 0.43 NonLiq 27.5 0.14 0.02 0.2 LB-4 6.3 to 8.8 7.5 2.5 35 120 32 2 1 20.8 900 35.5 47.6 >Range 900 0.35 0.43 NonLiq 47.6 0.01 0.00 0.2 LB-4 8.8 to 12.5 10 3.8 30 120 19 2 1 12.4 1200 19.4 27.1 0.341 1200 0.35 0.43 NonLiq 27.1 0.16 0.07 0.2 LB-4 12.5 to 17.5 15 5.0 80 120 16 1 1.26 20.1 1800 25.8 35.9 >Range 1800 0.3 40 . 4 2 NonLiq 35.9 0.06 0.04 0.1 LB-4 17.5 to 22.0 20 4.5 45 120 34 2 1 22.1 2400 27.4 37.9 >Range 2400 0.34 0. 42 NonLiq 37.9 0.08 0.04 0.0 LB-5 0 to 3.8 2.5 3.8 OX 85 120 50 1 1.3 65.0 300 116.0 144.2 >Range 300 0.36 0.43 NonLiq 144.2 0.00 0.00 0.2 LB-5 3.8 to 5.0 5 1.3 OX 30 120 50 1 1.3 65.0 600 116.0 138.6 >Range 600 0.35 0.43 NonLiq 138.6 0.00 0.00 0.2 LB-5 5.0 to 6.3 5 1.3 30 120 25 2 1 16.3 600 29.0 38.2 >Range 600 0.35 0.43 NonLiq 38.2 0.05 0.01 0.2 LB-5 6.3 to 8.8 7.5 2.5 15 120 22 2 1 14.3 900 24.4 28.1 0.372 900 0.35 0.43 NonLiq 28.1 0.10 0.03 0.2 LB-5 8.8 to 12.5 10 3.8 70 120 20 2 1 13.0 1200 20.4 29.5 0.435 1200 0.35 0.43 NonLiq 29.5 0.15 0.07 0.2 LB-5 12.5 to 17.5 15 5.0 85 120 11 1 1.16 12.8 1800 16.4 24.7 0.286 1800 0.34 0.42 NonLiq 24.7 0.14 0.08 0.1 LB-5 17.5 to 22.0 20 4.5 85 120 33 2 1 21.5 2400 26.6 36.9 >Range 2400 0.34 0. 42 NonLiq 36.9 0.08 0.04 0.0 LB-6 0 to 3.8 2.5 3.8 OX 90 120 50 1 1.3 65.0 300 116.0 144.2 >Range 300 0.36 0.43 NonLiq 144.2 0.00 0.00 0.2 LB-6 3.8 to 5.0 5 1.3 OX 30 120 50 1 1.3 65.0 600 116.0 138.6 >Range 600 0.35 0.43 NonLiq 138.6 0.00 0.00 0.2 LB-6 5.0 to 6.3 5 1.3 30 120 27 2 1 17.6 600 31.3 40.9 >Range 600 0.35 0.43 NonLiq 40.9 0.02 0.00 0.2 LB-6 6.3 to 8.8 7.5 2.5 40 120 21 2 1 13.7 900 23.3 32.9 >Range 900 0.35 0.43 NonLiq 32.9 0.05 0.01 0.2 LB-6 8.8 to 12.5 10 3.8 45 120 49 2 1 31.9 1200 50.0 65.0 >Range 1200 0.35 0.43 NonLiq 65.0 0.01 0.01 0.2 LB-6 12.5 to 17.5 15 5.0 75 120 18 1 1.3 23.4 1800 30.0 41.0 >Range 1800 0.34 0.42 NonLiq 41.0 0.02 0.01 0.2 LB-6 17.5 to 22.5 20 5.0 90 120 38 2 1 24.7 2400 30.6 41.8 >Range 2400 0.34 0. 42 NonLiq 41.8 0.02 0.01 0.2 LB-6 22.5 to 27.5 25 5.0 40 120 17 1 1.23 20.9 3000 23.2 32.9 >Range 3000 0.3 40 . 4 1 NonLiq 32.9 0.11 0.07 0.1 LB-6 27.5 to 32.5 30 5.0 80 120 54 2 1 35.1 3600 37.4 49.9 >Range 3600 0.33 0. 41 NonLiq 49.9 0.02 0.01 0.1 LB-6 32.5 to 37.5 35 5.0 20 120 27 1 1.3 35.1 4200 34.6 41.0 >Range 4200 0.32 0.39 NonLiq 41.0 0.02 0.01 0.1 LB-6 37.5 to 42.5 40 5.0 15 120 66 2 1 42.9 4800 39.6 44.0 >Range 4800 0.30 0. 37 NonLiq 44.0 0.02 0.01 0.0 LB-6 42.5 to 47.5 45 5.0 15 120 40 1 1.3 52.0 5400 45.3 49.9 >Range 5400 0.29 0.35 NonLiq 49.9 0.02 0.01 0.0 LB-6 47.5 to 52.0 50 4.5 10 120 84 2 1 54.6 6000 45.1 46.9 >Range 6000 0.27 0. 33 NonLiq 46.9 0.02 0.01 0.0 LB-7 0 to 3.8 2.5 3.8 OX 60 120 50 1 1.3 65.0 300 116.0 144.2 >Range 300 0.36 0.43 NonLiq 144.2 0.00 0.00 0.9 LB-7 3.8 to 5.0 5 1.3 OX 18 120 50 1 1.3 65.0 600 116.0 127.0 >Range 600 0.35 0.43 NonLiq 127.0 0.00 0.00 0.9 LB-7 5.0 to 6.3 5 1.3 18 120 6 2 1 3.9 600 7.0 10.7 0.119 600 0.35 0.43 NonLiq 10.7 1.52 0.23 0.9 LB-7 6.3 to 8.8 7.5 2.5 70 120 19 2 1 12.4 900 21.1 30.3 >Range 900 0.35 0.43 NonLiq 30.3 0.05 0.02 0.6 LB-7 8.8 to 12.5 10 3.8 85 120 51 2 1 33.2 1200 52.0 67.4 >Range 1200 0.35 0.43 NonLiq 67.4 0.01 0.01 0.6 LB-7 12.5 to 17.5 15 5.0 30 120 14 1 1.22 17.1 1800 21.9 29.9 0.463 1800 0.34 0.42 NonLiq 29.9 0.12 0.07 0.6 LB-7 17.5 to 22.0 20 4.5 5 120 17 2 1 11.1 2400 13.7 13.7 0.147 2400 0.34 0.42 NonLiq 13.7 0.98 0.53 0.5 Leighton Page 2 of 2
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices

APPENDIX E

GENERAL EA

RTHWORK AND GRADING SPECIFICATIONS
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices 1 3030.495
LEIGHTON AND AS SOCIATES, INC.

GENERAL EARTHWORK AND GRADING SPECIFICATIONS FOR ROUGH GRADING Table of Contents
Section Page

1.0 GENERAL 1

1.1 Intent 1

1.2 The Geotechnical Consultant of Record 1

1.3 The Earthwork Contractor 2

2.0 PREP
ARATION OF AREAS TO BE FILLED 2

2.1 Clea
ring and Grubbing 2

2.2 Processing 3

2.3 Overexcavation 3

2.4 Benching 3

2.5 Evaluation/Acceptance of Fill Areas 3

3.0 FILL M
ATERIAL 4

3.1 General 4

3.2 Oversize 4

3.3 Import 4

4.0 FILL
PLACEMENT AND COMPACTION 4

4.1 Fill La
yers 4

4.2 Fill Moisture Conditioning 4

4.3 Compaction of Fill 5

4.4 Compaction of Fill Slopes 5

4.5 Compaction Testing 5

4.6 Frequency of Compaction Testing 5

4.7 Compaction Test Locations 5

5.0 SUBDRAI
N INSTALLATION 6

6.0 EXCAVATI
ON 6

7.0 TRENC
H BACKFILLS 6

7.1 Safety 6

7.2 Bedding and Backfill 6

7.3 Lift Thickness 6

7.4 Observation and Testing 6
PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices 1 3030.495
LEIGHTON AND ASSOCIATES, INC.

General Earthwork and Grading Specifications

1.0 General

1.1 Intent: These General Earthwork and Grading Specifications are for the grading and earthwork shown on the approved grading plan(s) and/or indicated in the geotechnical report(s). These Specifications are a part of the recommendations contained in the geotechnical report(s). In case of conflict, the specific recommendations in the geotechnical report shall supersede these more general Specifications. Observations of the earthwork by the project Geotechnical Consultant during the course of grading may result in new or revised recommendations that could supersede these specifications or the recommendations in the geotechnical report(s).

1.2 The Geotechnical Consultant of Record: Prior to commencement of work, the owner shall employ the Geotechnical Consultant of Record (Geotechnical Consultant). The Geotechnical Consultants shall be responsible for reviewing the approved geotechnical report(s) and accepting the adequacy of the preliminary geotechnical findings, conclusions, and recommendations prior to the commencement of the grading.

Prior to commencement of grading, the Geotechnical Consultant shall review the "work plan" prepared by the Earthwork Contractor (Contractor) and schedule sufficient personnel to perform the appropriate level of observation, mapping, and compaction testing.

During the grading and earthwork operations, the Geotechnical Consultant shall observe, map, and document the subsurface exposur es to verify the geotechnical design assumptions. If the observed conditions are found to be significantly different than the interpreted assumptions during the design phase, the Geotechnical Consultant shall inform the owner, recommend appropriate change s in design to accommodate the observed conditions, and notify the review agency where required.

Subsurface areas to be geotechnically observed, mapped, elevations recorded, and/or tested include natural ground after it has been cleared for receiving fill but before fill is placed, bottoms of all "remedial removal" areas, all key bottoms, and benches made on sloping ground to receive fill.

The Geotechnical Consultant shall observe the moisture -conditioning and processing of the subgrade and fill materials and perform relative compaction testing of fill to determine the attained level of compaction. The Geotechnical Consultant shall provide the test results to the owner and the Contractor on a routine and frequent basis.

PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices 2 3030.495
LEIGHTON AND ASSOCIATES, INC.

General Earthwork and Grading Specifications

1.3 The Earthwork Contractor : The Earthwork Contractor (Contractor) shall be qualified, experienced, and knowledgeable in earthwork logistics, preparation and processing of ground to receive fill, moisture -conditioning and processing of fill, and compacting fill. The Contractor shall review and accept the plans, geotechnical report(s), and these Specifications prior to commencement of grading. The

Contractor shall be solely responsible for performing the grading in accordance with the plans and specifications.

The Contractor shall prepare and submit to the owner and the Geotechnical Consultant a work plan that indicates the sequence of earthwork grading, the number of "spreads" of work and the estimated quantities of daily earthwork contemplated for the site prior to commencement of grading. The Contractor shall inform the owner and the Geotechnical Consultant of changes in work schedules and updates to the work plan at least 24 hours in advance of such changes so that appropriate observations and tests can be planned and accomplished. The Contractor shall not assume that the Geotechnical Consultant is aware of all grading operations.

The Contractor shall have the sole responsibility to provide adequate equipment and methods to accomplish the earthwork in accordance with the applicable grading codes and agency ordinances, these Specifications, and the recommendations in the approved geotechnical report(s) and grading plan(s). If, in the opinion of the Geotechnical Consultant, unsatisfactory conditions, such as unsuitable soil, improper moisture condition, inadequate compaction, insufficient buttress key size, adverse weather, etc., are resulting in a quality of work less than required in these specifications, the Geotechnical Consultant shall reject the work and may recommend to the owner that construction be stopped until the conditions are rectified.

2.0 Preparation of Areas to be Filled

2.1 Clearing and Grubbing: Vegetation, such as brush, grass, roots, and other deleterious material shall be sufficiently removed and properly disposed of in a method acceptable to the owner, governing agencies, and the Geotechnical Consultant.

The Geotechnical Consultant shall evaluate the extent of these removals depending on specific site conditions. Earth fill material shall not contain more than 1 percent of organic materials (by volume). No fill lift shall contain more than 5 percent of organic matter. Nesting of the organic materials shall not be allowed.

PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices 3 3030.495
LEIGHTON AND ASSOCIATES, INC.

General Earthwork and Grading Specifications

If potentially hazardous materials are encountered, the Contractor shall stop work in the affected area, and a hazardous material specialist shall be informed immediately for proper evaluation and handling of these materials prior to continuing to work in that area.

As presently defined by the State of California, most refined petroleum products (gasoline, diesel fuel, motor oil, grease, coolant, etc.) have chemical constituents that are considered to be hazardous waste. As such, the indiscriminate dumping or spillage of these fluids onto the ground may constitute a misdemeanor, punishable by fines and/or imprisonment, and shall not be allowed.

2.2 Processing: Existing ground that has been declared satisfactory for support of fill by the Geotechnical Consultant shall be scarified to a minimum depth of 6 inches.

Existing ground that is not satisfactory shall be overexcavated as specified in the following section. Scarification shall continue until soils are broken down and free of large clay lumps or clods and the working surface is reasonably uniform, flat, and free of uneven features that would inhibit uniform compaction.

2.3 Overexcavation: In addition to removals and overexcavations recommended in the approved geotechnical report(s) and the grading plan, soft, loose, dry, saturated, spongy, organic-rich, highly fractured or otherwise unsuitable ground shall be overexcavated to competent ground as evaluated by the Geotechnical Consultant during grading.

2.4 Benching: Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal to vertical units), the ground shall be stepped or benched. Please see the Standard Details for a graphic illustration. The lowest bench or key shall be a minimum of 15 feet wide and at least 2 feet deep, into competent material as evaluated by the Geotechnical Consultant. Other benches shall be excavated a minimum height of 4 feet into competent material or as otherwise recommended by the Geotechnical Consultant. Fill placed on ground sloping flatter than 5:1 shall also be benched or otherwise overexcavated to provide a flat subgrade for the fill.

2.5 Evaluation/Acceptance of Fill Areas: All areas to receive fill, including removal and processed areas, key bottoms, and benches, shall be observed, mapped, elevations recorded, and/or tested prior to being accepted by the Geotechnical Consultant as suitable to receive fill. The Contractor shall obtain a written acceptance from the Geotechnical Consultant prior to fill placement. A licensed surveyor shall provide the survey control for determining elevations of processed areas, keys, and benches.

PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices 4 3030.495
LEIGHTON AND ASSOCIATES, INC.

General Earthwork and Grading Specifications

3.0 Fill Material

3.1 General: Material to be used as fill shall be essentially free of organic matter and other deleterious substances evaluated and accepted by the Geotechnical Consultant prior to placement. Soils of poor quality, such as those with unacceptable gradation, high expansion potential, or low strength shall be placed in areas acceptable to the Geotechnical Consultant or mixed with other soils to achieve satisfactory fill material.

3.2 Oversize: Oversize material defined as rock, or other irreducible material with a maximum dimension greater than 8 inches, shall not be buried or placed in fill unless location, materials, and placement methods are specifically accepted by the Geotechnical Consultant. Placement operations shall be such that nesting of oversized material does not occur and such that oversize material is completely surrounded by compacted or densified fill. Oversize material shall not be placed within 10 vertical feet of finish grade or within 2 feet of future utilities or underground construction.

3.3 Import: If importing of fill material is required for grading, proposed import material shall meet the requirements of Section 3.1. The potential import source shall be given to the Geotechnical Consultant at least 48 hours (2 working days) before importing begins so that its suitability can be determined and appropriate tests performed.

4.0 Fill Placement and Compaction

4.1 Fill Layers: Approved fill material shall be placed in areas prepared to receive fill (per Section 3.0) in near-horizontal layers not exceeding 8 inches in loose thickness.

The Geotechnical Consultant may accept thicker layers if testing indicates the grading procedures can adequately compact the thicker layers. Each layer shall be spread evenly and mixed thoroughly to attain relative uniformity of material and moisture throughout.

4.2 Fill Moisture Conditioning: Fill soils shall be watered, dried back, blended, and/or mixed, as necessary to attain a relatively uniform moisture content at or slightly over optimum. Maximum density and optimum soil moisture content tests shall be performed in accordance with the American Society of Testing and Materials (ASTM Test Method D1557-91).

PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices 5 3030.495
LEIGHTON AND ASSOCIATES, INC.

General Earthwork and Grading Specifications

4.3 Compaction of Fill: After each layer has been moisture- conditioned, mixed, and evenly spread, it shall be uniformly compacted to not less than 90 percent of maximum dry density (ASTM Test Method D1557- 91). Compaction equipment shall be adequately sized and be either specifically designed for soil compaction or of proven reliability to efficiently achieve the specified level of compaction with uniformity.

4.4 Compaction of Fill Slopes: In addition to normal compaction procedures specified above, compaction of slopes shall be accomplished by backrolling of slopes with sheepsfoot rollers at increments of 3 to 4 feet in fill elevation, or by other methods producing satisfactory results acceptable to the Geotechnical Consultant. Upon completion of grading, relative compaction of the fill, out to the slope face, shall be at least 90 percent of maximum density per ASTM Test Method D1557-91.

4.5 Compaction Testing: Field tests for moisture content and relative compaction of the fill soils shall be performed by the Geotechnical Consultant. Location and frequency of tests shall be at the Consultant's discretion based on field conditions encountered. Compaction test locations will not necessarily be selected on a random basis. Test locations shall be selected to verify adequacy of compaction levels in areas that are judged to be prone to inadequate compaction (such as close to slope faces and at the fill/bedrock benches).

4.6 Frequency of Compaction Testing: Tests shall be taken at interv als not exceeding 2 feet in vertical rise and/or 1,000 cubic yards of compacted fill soils embankment.

In addition, as a guideline, at least one test shall be taken on slope faces for each 5,000 square feet of slope face and/or each 10 feet of vertical height of slope. The Contractor shall assure that fill construction is such that the testing schedule can be accomplished by the Geotechnical Consultant. The Contractor shall stop or slow down the earthwork construction if these minimum standards are not met.

4.7 Compaction Test Locations : The Geotechnical Consultant shall document the approximate elevation and horizontal coordinates of each test location. The Contractor shall coordinate with the project surveyor to assure that sufficient grade stakes are established so that the Geotechnical Consultant can determine the test locations with sufficient accuracy. At a minimum, two grade stakes within a horizontal distance of 100 feet and vertically less than 5 feet apart from potential test locations shall be provided.

PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices 6 3030.495
LEIGHTON AND ASSOCIATES, INC.

General Earthwork and Grading Specifications

5.0 Subdrain Installation

Subdrain systems shall be installed in accordance with the approved geotechnical report(s), the grading plan, and the Standard Details. The Geotechnical Consultant may recommend additional subdrains and/or changes in subdrain extent, location, grade, or material depending on conditions encountered during grading. All subdrains shall be surveyed by a land surveyor/civil engineer for line and grade after installation and prior to burial.

Sufficient time should be allowed by the Contractor for these surveys.

6.0 Excavation

Excavations, as well as over -excavation for remedial purposes, shall be evaluated by the Geotechnical Consultant during grading. Remedial removal depths shown on geotechnical plans are estimates only. The actual extent of removal shall be determined by the Geotechnical Consultant based on the field evaluation of exposed conditions during grading. Where fill-over-cut slopes are to be graded, the cut portion of the slope shall be made, evaluated, and accepted by the Geotechnical Consultant prior to placement of materials for construction of the fill portion of the slope, unless otherwise recommended by the Geotechnical Consultant.

7.0 Trench Backfills

7.1 Safety: The Contractor shall follow all OHSA and Cal/OSHA requirements for safety of trench excavations.

7.2 Bedding and Backfill: All bedding and backfill of utility trenches shall be done in accordance with th e applicable provisions of Standard Specifications of Public Works Construction. Bedding material shall have a Sand Equivalent greater than 30 (SE>30). The bedding shall be placed to 1 foot over the top of the conduit and densified by jetting. Backfill shall be placed and densified to a minimum of 90 percent of maximum from 1 foot above the top of the conduit to the surface.

The Geotechnical Consultant shall test the trench backfill for relative compaction.

At least one test should be made for every 300 feet of trench and 2 feet of fill.

7.3 Lift Thickness: Lift thickness of trench backfill shall not exceed those allowed in the Standard Specifications of Public Works Construction unless the Contractor can demonstrate to the Geotechnical Consultant that the fill lift can be compacted to the minimum relative compaction by his alternative equipment and method.

7.4 Observation and Testing: The jetting of the bedding around the conduits shall be observed by the Geotechnical Consultant.

PR-2022-001434 (GP, RZ, DR, VC-S) Exhibit 10 - Draft Mitigated Negative Declaration and Appendices