Ukiah City Council
June 21, 2023

DRAFT GEOTECHNICAL REPORT (Revision 2) Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California February 3, 2023

APPENDIX I
Figure 1 – Vicinity Map
Figure 2 – Exploration Location Map
Figure 3 – Geologic Map
Figure 4 – Fault Map

APPENDIX II
2022 Crawford Boring Legend and Logs
2017 Crawford Boring Logs
2014 LACO Boring Logs

APPENDIX III
Laboratory Test Results
Hazardous Materials Laboratory Results

APPENDIX IV
Site-Specific Ground Motion Hazard Analysis
Appendix B-6 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT (Revision 2) Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California February 3, 2023
1 1 INTRODUCTION

1.1 PURPOSE
Crawford & Associates, Inc. (Crawford) prepared this Geotechnical Report for the City of Ukiah Wastewater Treatment Plant (WWTP) Improvements as part of the Recycled Water Pipeline – Phase 4 Design Project. This report is intended to provide geotechnical and geologic data and provide conclusions and recommendations addressing the planned basin, wet well, and electrical improvements at the WWTP.

1.2 GEOTECHNICAL SERVICES
To prepare this report, Crawford:
• Discussed the project with Jason Benson, PE, with the City of Ukiah, Alan Hodge with the City of Ukiah WWTP and Brian Avon, PE and Craig Andrews with Carollo Engineers (Carollo);
• Attended a kick-off meeting at the site to meet with the design team and Alan Hodge to discuss project needs and objectives;
• Reviewed historical geotechnical data in the LACO report “Ukiah Recycled Water Pipeline, Geotechnical Report” dated October 17, 2014.
• Reviewed historical geotechnical data in the Crawford Geotechnical Report “City of Ukiah Chlorine Contact Basin Expansion, Geotechnical Report” dated November 4, 2017. • Reviewed the Carollo 60% design submittal “Storage Pond Grading Plan” dated August 2022;
• Reviewed available geologic and seismic maps;
• Drilled and sample two test borings to a maximum depth of 31.5 feet (ft) below ground surface (bgs);
• Performed laboratory tests on representative soil samples from the exploratory borings; • Performed a site-specific ground motions hazard analysis; • Performed geotechnical engineering analysis for design and construction of the proposed concrete lined basin, pump station and electrical component improvements; and • Developed conclusions and recommendations.
2 PROJECT DESCRIPTION
The City of Ukiah WWTP plans to upgrade their wastewater treatment facility by demolishing two of their existing sludge basins that are currently not in use. Following demolition of the two sludge basins, the WWTP plans to construct a new lined basin covering the area of both existing basins. In addition, the project proposes to install a wet well and electrical equipment supported on a mat foundation.

Based on the Storage Pond Grading Plan (August 2022), we understand that the current planned finished grade for the bottom of the basin is at elevation 570 ft, however we understand this elevation is flexible. The plan sheet shows that one embankment will surround the new basin. The embankment crest elevation is 581 ft and will be 13 ft wide, and the embankment slopes will be 3 horizontal to 1 vertical (3H:1V) for the inner slopes and 3H:1V for the outer Appendix B-7 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT (Revision 2) Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California February 3, 2023
2 slopes. We understand the new embankment will be constructed by generally adding new fill to the old embankment. The new inner slopes will extend into the existing basin and sludge area.

An access road leading inside the basin is planned along the east embankment, as well as around the crown of the basin. Two inlets are planned to be on the north and east inner slopes.

We understand the new wet well will be constructed at the center of the north embankment.

The wet well is planned to be 180 sq. ft. with a planned inlet elevation of 570 ft. The wet well is planned to be founded on a mat foundation. Additionally, a shallow mat foundation will likely support the electrical components of the wet well. The electric components are proposed to be located approximately 30 ft northeast of the basin next to an existing electric panel. The details of the electric components were not established at the time of this report. 3 SITE DESCRIPTION
The existing sludge basins are located within the City of Ukiah WWTP at 391 Plant Road in Ukiah, CA. The site coordinates used for the project site are approximate latitude 39.1117° and longitude -123.1900°. We understand that the two sludge basins were originally constructed in the 1950’s as one large basin, however a berm was later constructed in the center of the basin which separated the large basin into two basins (see Photo 1 below). The basins combined measure approximately 500 ft wide by 300 ft long.

The existing ground surface within the basins range from elevation 572 ft to 574 ft. The existing berm surrounding the two basins has a surface elevation of approximately 581 ft, and the existing center berm separating the two basins has a surface elevation of approximately 576 ft.

The basin neighbors the City of Ukiah WWTP’s percolation ponds to the east, recycled water storage ponds to the south, railroads tracks to the west, and the City of Ukiah WWTP to the north.

We provide a Vicinity Map shown on Figure 1 in Appendix I.

Appendix B-8 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT (Revision 2) Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California February 3, 2023
3 Photo 1: Central Berm Showing Both Basins Facing South 4 SITE GEOLOGY
The project site lies within the Coast Ranges Geomorphic Province, characterized by a series of northwest trending mountain ranges sub-parallel to the San Andres Fault. The Coast Ranges is composed of thick Mesozoic and Cenozoic sedimentary strata. The northern Coast Ranges are dominated by the irregular, knobby, landslide-topography of the Franciscan Complex. The project site is located within the Ukiah Valley, an alluvial valley situated within the Coast Ranges.

The Geologic Map of California: Ukiah Sheet1 shows the site as being underlain by Quaternary (Recent) alluvium. The alluvium consists of predominately unconsolidated gravel, sand, silt, and clay deposited in channels and on floodplains of the Russian River (located adjacent to the facility property). Quaternary (Pleistocene) age non-marine terrace deposits are also mapped on site, which consist of gravelly clay to sandy/silty gravel.2

We provide a Geologic Map on Figure 3 in Appendix I.
5 SUBSURFACE CONDITIONS

5.1 FIELD EXPLORATION

5.1.1 SOIL BORINGS
Crawford retained Geo-Ex Subsurface Exploration to drill two exploratory borings on August 30, 2022 within the sludge basin, and Taber Drilling to drill two exploratory borings on September 27, 2017 for the nearby chlorine contact basin project. LACO retained Clear Heart Drillers to drill four borings within the existing basin embankments on September 11, 2014 for the Ukiah Recycled Water Project. Table 1 provides a subsurface exploration summary for the borings considered for this study.
1 Jennings, C.W. and Strand, R.G., (1960), Geologic Map of California: Ukiah Sheet 2 California Department of Water Resources (2004), Ukiah Valley Ground Water Basin, California groundwater Bulletin 118
Appendix B-9 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT (Revision 2) Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California February 3, 2023
4 Table 1: Subsurface Exploration Summary
Boring
Number
Completion
Date
Drill Rig Type/
Drilling
Equipment
Type
Hammer
Type
Hammer
Efficiency
(%)
Approx.

Ground
Surface
Elevation (ft)
Boring
Depth
(ft)
Crawford Exploratory Borings (2022)
A-22-001 9/30/2022 D50(Track
Mounted) Auto 101.91 581 31.5
A-22-002 9/30/2022 576 26.5
DCP-22-
001 9/22/2022
N/A
35 lb
18-in
drop
N/A
573 10.0
DCP-22-
002 9/22/2022 573 9.6
Crawford Exploratory Borings (2017)
B1 9/27/2017 CME 55 (Truck
Mounted) Auto 822 --4 50.0
B2 9/27/2017 --4 26.5
LACO Exploratory Borings (2014)
B-15 9/11/2014
CME 75 (Track
Mounted) Auto N/A3
587 21.5
B-16 9/11/2014 586 21.5
B-17 9/11/2014 576 21.5
B-19 9/11/2014 588 21.5

1. A hammer energy calibration test was not performed specifically for this project/site; however, a previous hammer energy testing result provided by Geo-Ex found the hammer to have an energy efficiency of 101.9%.

2. A hammer energy calibration test was not performed specifically for this project/site; however, a previous hammer energy testing result provided by Taber Drilling found the hammer to have an energy efficiency of 82%.

3. A hammer energy calibration test was not recorded in the boring logs.

4. Elevations were not recorded at the time of the published report.

Soil samples were recovered by means of a 2.0-inch O.D. “Standard Penetration” split-spoon sampler without 1.4-inch stainless steel liners and a 3.0-inch O.D. “Modified California” splitspoon sampler with 2.4-inch stainless steel liners. Relatively undisturbed samples were also recovered by means of a 3-inch OD thin-walled Shelby sampler. The shelby samples were “pushed” in to recover sample and the “resistance” was measured (in psi). Drive samplers were advanced with standard 350 ft-lb striking force using a 140 lb. automatic hammer and a drop height of 30 inches. Sampler penetration resistance was recorded to provide a field measure of relative densities and can be correlated to soils strength and bearing characteristics.

Consistency of cohesive soils were obtained in the field by means of pocket penetrometer and field pocket torvanes. The field-recorded (uncorrected) blow counts and down pressure used to insert the Shelby tubes are shown on our 2022 boring logs in Appendix II. 2017 Crawford and 2014 LACO boring logs are attached in Appendix II. Boring locations are shown on the Exploration Map on Figure 2 in Appendix I.

Crawford’s project engineers and geologists logged the exploratory borings consistent with the Unified Soil Classification System (USCS) and the 2010 Caltrans Logging Manual. Crawford retained samples from the borings in sealed constrainers for laboratory testing and reference.

Groundwater observations were recorded during drilling operations when encountered. At Appendix B-10 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT (Revision 2) Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California February 3, 2023
5 completion, the exploratory borings were backfilled following Mendocino County Environmental Health requirements.

5.1.2 DYNAMIC CONE PENETROMETER
The Dynamic Cone Penetrometer (DCP) test provides an approximate quantification of a material’s apparent density or stiffness. For this project, DCP testing was completed using manual equipment as described below. The purpose of the test was to aid in understanding the thickness of the soft/loose sludge sediments and soil, and the depth to more competent bearing materials within the existing basins.

Crawford project engineers completed a total of two DCP tests on September 22, 2022. The DCP tests were completed using a hand-operated tool called a “Wildcat DCP,” manufactured by Triggs Technology, Inc. The test consists of continuously driving a 1.4-inch O.D. steel cone tip attached to a lead rod until refusal (50 blows per approximately 4-inches) is reached. The rods are advanced using a hand-actuated, 35-lb safety drop hammer falling a distance of 15-inches.

5.2 SUBSURFACE SOIL/ROCK
The subsurface soils encountered in the 2022 borings are generally consistent with the materials encountered in the 2017 Crawford and 2014 LACO borings and published mapping for the site vicinity. We summarize the encountered materials as described below.

Sludge Basin – The explorations completed within the existing sludge basin and center berm indicate that very soft deleterious material (likely sludge) is present to an elevation of about 566.5 ft to 567.5 ft, or about 5.5 ft to 6.5 ft below existing basin grade.

Perimeter Berm – Embankment fill consisting of tan, medium dense, silty sand was encountered from berm grade (approximate elevation 581 ft) to elevation 576 ft. The embankment fill was underlain by soft to hard lean clay and loose to medium dense clayey sand, encountered between elevations 576 ft to 550 ft. Gravelly lean clay was encountered beneath this layer at elevation 550 ft. and based on nearby borings performed for the Chlorine Contact Basin Project, this layer extends to the maximum depth explored, likely between elevations3 520 ft and 530 ft.

We present more detailed descriptions of the subsurface soils on the boring logs in Appendix II.

5.3 GROUNDWATER
We encountered groundwater in boring A-22-001 at approximate elevation 560 ft (21 ft bgs) and we did not encounter groundwater in boring A-22-002. Our 2017 borings encountered groundwater at approximate elevations 572.2 ft and 563.6 ft for borings B1 and B2, respectively.

LACO encountered groundwater in their boring B-17 at an approximate elevation of 565 ft on September 11, 2014. Based on our conversations with the city, groundwater was not encountered at the time the Chlorine Contact Basin was constructed.

The WWTP staff provided historical groundwater elevations for two monitoring wells (GW-01 and GW-02) in the vicinity of the plant for the 2017 Chlorine Content Basin report. According to 3 Actual boring elevations were not recorded for the 2017 Crawford borings. Elevations were estimated from current topographic information provided by Carollo.

Appendix B-11 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT (Revision 2) Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California February 3, 2023
6 WWTP staff, GW-1 and GW-2 were relocated from their previous location referenced in the 2017 report. The new locations for Monitoring wells GW-01 and GW-02 are located about 50 to 100 feet south and 1,500 to 1600 feet east of the southern embankment, respectively. To supplement the data from 2017, Table 2 below shows groundwater data previously measured, as well as recent groundwater measurements from the relocated monitoring wells.

Table 2: Summary of Subsurface Exploration
Date
2017 CCB Report 2023 Sludge Basin Report
GW-021 GW-012 GW-01 GW-02
Elevation3 Elevation4
Mar-04 554.22 564.23 N/A N/A
Oct-04 550.56 559.63 N/A N/A
Mar-05 559.05 564.22 N/A N/A
Oct-05 550.53 561.8 N/A N/A
Mar-06 556.1 565.24 N/A N/A
Oct-06 550.14 559.71 N/A N/A
Apr-07 553.64 563.58 N/A N/A
Oct-07 551.932 557.29 N/A N/A
Mar-08 555.9 563.87 N/A N/A
Oct-08 551.66 563.12 N/A N/A
Mar-09 554.8 554.18 N/A N/A
Oct-09 550.65 564.67 N/A N/A
Mar-10 555.25 557.57 N/A N/A
Oct-10 550.33 563.91 N/A N/A
Apr-11 550.72 557.07 N/A N/A
Oct-11 550.7 550.68 N/A N/A
Jul-12 N/A 565.27 N/A N/A
Aug-12 N/A 563.27 N/A N/A
May-21 N/A N/A 561.81 551.36
Feb-21 N/A N/A 564.11 561.52
Aug-21 N/A N/A 557.17 550.02
Oct-21 N/A N/A 561.97 563.96
Feb-22 N/A N/A 564.58 556.0
Jul-22 N/A N/A 559.78 550.63
May-22 N/A N/A 563.42 553.62
Oct-22 N/A N/A 557.94 551.77 1Formally MW-1, 2Formally MW-2 3Well elevations provided by the Rau & Associates, Inc. 2017 4 Elevations provided by City of Ukiah WWTP Appendix B-12 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT (Revision 2) Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California February 3, 2023
7 Based on our understanding of the site conditions, flooding occurs throughout the winter months and the buoyancy forces should be estimated based on historical and/or expected high water events at the site. The recent groundwater data, from the WWTP, show the design groundwater elevation fluctuates between elevation 565 ft and 560 ft. 6 LABORATORY TESTS
The following laboratory tests were completed on representative soil samples obtained from the 2022 exploratory borings complete by Crawford:
• Grain Size Analysis (ASTM D6913)
• Moisture Content-Dry Density (ASTM D2216, ASTM D2937) • No. 200 Wash (ASTM D1140)
• Plasticity Index (ASTM D4318)
• pH and Minimum Resistivity (CTM 643)
• Redox Potential (ASTM G-200m)
• Sulfate Content (CTM 417)
• Sulfides (AWWA C105/A25.5)
• Unconfined Compression (ASTM D2166)
The following laboratory testing was completed on the soil/sludge samples obtained from the 2022 exploratory borings completed by Crawford:
• CAM 17 Heavy Metals (EPA 6010/7470)
• Purgeable Aromatics and Total Petroleum Hydrocarbons (EPA 8015) • Total Concentrations (TTLC)
• Volatile Organic Content (EPA 8260)
We present the laboratory test results in Appendix III. 7 CORROSION CONSIDERATIONS
A soils corrosivity analysis is important for estimating and mitigating the deterioration of buried ferrous metals and concrete. Soil corrosivity tests were completed on four samples obtained from the field exploration. Results of the soil corrosion tests are summarized in Table 4. Detailed laboratory results are included in Appendix III. Table 4 summarizes the results of soil corrosivity tests on samples from our test borings.

Table 3: Soil Corrosion Test Summary
BoringSample
Number
Depth
(ft)
Minimum
Resistivity
(Ohm-cm)
Soil
pH
Chloride
Content
(ppm)
Sulfate
Content
(ppm)
Redox
Potential
(mv)
Sulfides
Presence
A-22-001-3B 5.0 2,950 6.84 4.8 27.5 + 212 NEGATIVE
A-22-002-4A 6.0 1,470 7.05 15.3 31.6 N/A N/A
Appendix B-13 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT (Revision 2) Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California February 3, 2023
8 To evaluate the potential for external corrosion potential on ductile iron pipe from soil, the 10- point system in C105/A21.5 (ANSI/AWWA 1999) was used. The 10-point system is a methodology used to determine the corrosive nature of a soil to ferrous metals based on the resistivity, pH, redox potential, sulfides presence, and drainage characteristics. The results of the 10-point system analysis showed a maximum of two points; which indicates a non-corrosive environment (AWWA 2005).

According to the American Concrete Institute (ACI) 318, a sulfate concentration less than 1,000 parts per million (ppm) is considered negligible. A chloride content of less than 600 ppm is generally non-corrosive to reinforced concrete.

Based on the results of tested samples, the soil may be generally characterized as “noncorrosive” to concrete and ferrous metals. The tests results are only an indicator of soil corrosivity and the designer should consult with a corrosion engineer if these values are considered significant.
8 BASIN CONTENTS
Soil samples were collected from the sludge basin on September 30, 2022, between elevations 567 ft to 565 ft (7.5 to 9.5 ft bgs) in boring A-22-002 (collected using a Shelby tube) and submitted to Pace Analytical (ELAP #2961) for preliminary analysis on October 25, 2022.

Samples were was analyzed for Volatile Organics (EPA Method 8260B), Purgeable Aromatics and Total Petroleum Hydrocarbons (EPA Method 8015B), and CAM 17 Metals (EPA Methods 6010B and 7471A). We summarize the results below and attach a copy of the Pace report in Appendix III.

Volatile Organics – Tetrachloroethene (0.011 milligrams/kilogram[mg/kg]), toluene (0.0051 mg/kg), and xylenes (0.0016 mg/kg) were reported in the sample; the laboratory noted that the sample was analyzed outside of hold time. These reported concentrations do not exceed applicable hazardous waste limits.

Purgeable Aromatics and Total Petroleum Hydrocarbons – Gasoline Range Organics were reported in this sample at a concentration of 0.78 mg/kg; the laboratory noted that the sample was analyzed outside of hold time. This reported concentration does not exceed applicable hazardous waste limits.

CAM 17 Metals – None of the reported metal concentrations exceeded their respective Total Threshold Limit Concentrations (TTLC), nor did any of the reported metals concentrations exceed ten times their respective Soluble Threshold Limit Concentration (STLC); further analysis of this sample for soluble concentrations is not warranted. Reported metals concentrations do not exceed applicable hazardous waste limits.

Based on the analytical data from the soil sample from boring A-22-002, it does not appear that concentrations of Volatile Organics, Purgeable Aromatics and Total Petroleum Hydrocarbons, or CAM 17 metals exceed applicable hazardous waste limits. The soil samples collected were not preserved and delivered within the specified time limit (‘hold time”). As a result, the above results are meant to be preliminary and proper testing and sampling should be performed during construction prior to excavation or disposal.
9 SEISMIC DESIGN PARAMETERS
Appendix B-14 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT (Revision 2) Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California February 3, 2023
9 Crawford completed a site-specific ground motion hazard analysis in accordance with ASCE 7- 16 Section 11.4.8 and a summary of the seismic design parameters are presented in Table 5.

Table 4: Seismic Design Parameters
Design Parameter Value (g)
Design Spectral Acceleration for Short Period (SDS) 1.004 Design Spectral Acceleration for 1 sec Period (SD1) 0.959 MCE Spectral Response Acceleration for short Period (SMS) 1.506 MCE Spectral Response Acceleration Parameter for 1 sec Period (SM1) 1.438 See Appendix IV for the detailed site-specific ground motion hazard analysis.

9.1 SURFACE FAULT RUPTURE
No known active faults are mapped within or through the project area. The California Geologic Survey (CGS) considers a fault to be active if it has shown movement one or more times during the Holocene period, defined as the last 11,700 years. According to the CGS, the closest active fault is the Maacama Fault about 1.8 miles east of the site. Based on this mapping we consider the potential for fault rupture at the site low.

We present a fault activity map as Figure 4.

9.2 LIQUEFACTION POTENTIAL AND SEISMICALLY INDUCED SETTLEMENT Soil liquefaction can occur when saturated, relatively loose sand and specific soft, fine-grained saturated soils are subject to ground shaking strong enough to create soil particle separation that results from increased pore pressure. This separation and subsequent pore pressure dissipation can lead to decreased soil shear strength and settlement. Liquefaction is known to occur in soils ranging from low plasticity silts to gravels. However, soils most susceptible to liquefaction are clean sands to silty sands and non-plastic silts.

To evaluate the potential for soil liquefaction to occur at the site, Crawford used the simplified procedure outlined by Youd et al. (2001)4
, the 2022 and 2017 Crawford boring data, the 2014
LACO boring data, laboratory test results, design groundwater level of elevation 565 ft, and seismicity data from our site-specific hazards analysis summarized in Section 9 above and attached in Appendix IV.

The 2014 LACO borings were not deep enough to accurately perform liquefaction analysis, however the LACO borings indicate the potential for liquefaction is considered low due to primarily encountering clayey soils. Based on the soil conditions encountered in the 2017 Crawford borings, our analysis indicates a liquefaction potential index of 2.3 categorizing the site as low risk with a liquefaction induced settlement of less than 1 inch, within the silty sand layer located about 25 ft bgs at the chlorine contact basin location. However, this sand layer was not encountered in our 2022 Crawford borings. Therefore, this sand layer is likely discontinuous across the site. Based on the encountered soil conditions, we expect the potential 4 Youd & Idriss: Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils, April 2001 Appendix B-15 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT (Revision 2) Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California February 3, 2023
10 for liquefaction within the proposed sludge basin and wet well to be low but may still result in up to 1 inch of settlement.

LATERAL SPREADING AND seismic SLOPE inSTABILITY
Site topography is relatively flat, with predominately clayey soils, and the liquefaction potential is low therefore, we consider lateral spreading and seismic slope instability not to be a concern at this site.
10 CONCLUSIONS AND RECOMMENDATIONS
We conclude that the site is suitable from a Geotechnical standpoint for the proposed improvements. Key Geotechnical considerations include groundwater near the base of the basin excavation (which may cause difficult construction conditions), presence of soft deleterious materials (i.e. sludge) within the basin, and the presence of saturated soils.

10.1 GRADING
We understand that the WWTP is seeking design alternatives for both concrete liner and plastic liner systems. The grading recommendations below should provide adequate support for both liner alternatives. Excessively soft sediments should be prepared following the recommendations below, regardless of liner type selection.

10.1.1 ORIGINAL GROUND & SUBGRADE PREPARATION
Prior to site grading, clear the site to remove vegetation, debris, unneeded utilities, and other deleterious materials. Process and compact the exposed subgrade in new structure and/or fill areas as follows:
• Scarify the subgrade to a depth of approximately 10 inches. • Moisture condition subgrade soil to at least 2% over optimum moisture content and compact to a minimum 90% relative compaction per ASTM D1557.

We encountered saturated (saturation ranging between 90 to 99%) lean clays and clayey sands near the expected bottom of excavation which will likely require drying back. Should difficult construction conditions be encountered, we recommend alternative methods of subgrade preparation. Based on the expected size of exposed subgrade, chemical treatment is likely an economic option. Alternatively, the subgrade could be replaced with fabric wrapped crushed rock and/or aggregate base with and without geosynthetics and/or geogrids could potentially provide a stable working platform.

10.1.2 EXCAVATABILITY
Based on the data collected during this and previous exploration programs, soils should be excavatable with typical grading equipment such as backhoes, excavators, and scrapers.

10.1.3 OVEREXCAVATION
The DCP tests completed within the basin and borings within the embankments indicate very soft sludge sediments to about elevation 567 ft. To reduce settlement and to create a firm, unyielding surface, the soft sediments within the existing basin should be removed within the planned lined basin area. Within the proposed lined basin area, overexcavate the near surface Appendix B-16 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT (Revision 2) Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California February 3, 2023
11 very soft sludge sediments to elevation5 566 ft. Extend overexcavation 5 ft laterally beyond the edge of the basin bottom, this will require some reworking of the existing embankment.

10.1.4 FILL PLACEMENT & COMPACTION
Place fill in maximum 8-inch-thick loose lifts, moisture condition to at least optimum moisture content and compact to a minimum 90% relative compaction per ASTM D1557. Native materials, minus organics, debris and other deleterious materials, are suitable for engineered fill if not exceeding a maximum particle size of 4 inches. Excavated materials unsuitable for use as structural fill can be placed outside the structure limits, or disposed off-site.

10.1.5 IMPORT FILL
Import fill should be free of deleterious debris and meet the following requirements:
• Plasticity Index of less than 15
• Organic content of less than 2%
• Sieve Size Percentage Passing
If imported soil is required for construction, Crawford must review and approve the soils for use prior to transport to the site.

10.1.6 OVER-OPTIMUM SOIL MOISTURE
Excessively over-optimum (wet) soil conditions can make proper compaction difficult or impossible. Due to the shallow groundwater at the site wet soil will likely be encountered during construction. In general, wet soil can be mitigated by:
• Discing the soil during prolonged periods of dry weather, • Overexcavating and replacing with drier material,
• Stabilizing using aggregate and/or stabilization fabric or grid.

Crawford should observe the conditions and provide more specific mitigation recommendations during construction.

10.1.7 BENCHING
Bench fill into the existing embankment at a minimum of one foot horizontally for every one foot of fill placed, or as necessary to remove loose material and provide proper compaction along the zone of transition.

10.2 BASIN
5 This elevation is estimated based on the provided topographic survey and limited subsurface exploration information. Crawford must observe the bottom of the excavation to confirm the presence of firm, unyielding native materials prior to placing fill, rebar or concrete.
3-inch 100
No. 4 35 - 100
No. 30 20 - 100
No. 200 10 – 45
Appendix B-17 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT (Revision 2) Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California February 3, 2023
12 Based on our conversations with the City and Carollo, the planned finished grade for the bottom of the basin is elevation 570 ft. Our DCP tests completed within the existing basin area indicate the very soft sludge materials extend to about elevation 566.5 ft to 567.5 ft (about 5.5 to 6.5 ft bgs). To improve support and reduce settlement, the very soft sludge materials within the existing basin should be removed to about elevation 567 ft (See Section 10.1.3), and replaced with engineered fill or the basin bottom be lowered to achieve support within the more competent native soil below an elevation of 567 ft. Following the overexcavation of the very soft sludge sediments, the exposed subgrade at about elevation 567 ft should be scarified, moisture conditioned and compacted per Section 10.1. The designer should consider the potential for buoyancy forces when designing the bottom of the basin elevation.

10.2.1 FOUNDATION DESIGN PARAMETERS
Support for the proposed reconstructed sludge basin can achieve support for the foundation elements in compacted engineered fill or firm processed native soils below an elevation of 567 ft.

Use a modulus of subgrade reaction of 15 k/ft3 (corresponds to an allowable 1,250 psf for 1 inch of settlement). The proposed sludge basin is expected to settle on the order of 1 inch with a differential settlement of about ½ inch over a distance of about 50 ft. We expect this settlement to occur during construction.

Resistance to lateral loads (including those due to wind or seismic forces) may be determined using a coefficient of friction of 0.40 between the bottom of cast-in-place concrete foundations and the underlying soils. Lateral resistance for foundations is also available from passive soil pressure acting against the vertical face of the footings and the structure. The allowable passive pressures available may be taken as equivalent to pressures exerted by fluids weighing 220 psf per foot of embedment depth, up to a maximum of 2,000 psf. The passive pressure is only applicable if the retained earth is allowed to strain at least 0.02H.

These two modes of resistance can be combined; however, since horizontal movement is required to mobilize passive resistance, decrease the passive pressure by one-half if both friction and passive pressures are used.

Clean foundation excavations of debris and loose soil/rock prior to placing structural concrete.

Slope the ground surface away from the structures to direct surface water away from the facility.

10.2.2 BUOYANCY RESISTANCE
If buoyancy uplift will be a design consideration, buoyancy forces can be counter balanced using thickened slabs or pressure relief valves.

10.3 WET WELL

10.3.1 FOUNDATION DESIGN PARAMETERS
We understand that the wet well is planned to be supported on a mat foundation between elevations 567 ft to 568 ft. Based on information from our A-22-001 boring, loose clayey sand was encountered to an elevation of 568 ft. Provided the cast-in-place structure achieves uniform support within the underlying loose clayey sands at about elevation 568 ft, a modulus of subgrade reaction of 18 k/ft3 (corresponds to an allowable 1,500 psf for 1 inch of settlement) can Appendix B-18 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT (Revision 2) Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California February 3, 2023
13 be used for design. Total and differential foundation settlement is expected to be less than 1 inch and ½ inch, respectively.

Lateral forces may be resisted by friction developed between the base of the footing and the underlying soil. Use a coefficient of friction of 0.45 for concrete cast against soil to resist sliding.

Additional lateral resistance may be provided by assuming a passive pressure based on an equivalent fluid weight of 270 pcf. The passive capacity reduces to an equivalent fluid weight of 150 pcf during a seismic event. In designing the structure to resist lateral loads, the upper 12 inches of soil should be ignored.

Clean foundation excavations of debris and loose soil/rock prior to placing structural concrete.

Slope the ground surface away from the structures to direct surface water away from the facility.

10.3.2 BUOYANCY RESISTANCE
We expect buoyancy uplift will not be a design consideration for the wet well. However, buoyancy forces can be counter balanced using thickened slabs or base extensions. If base extensions are used, uplift resistance is provided by the effective unit weight of the soil column directly above the base extension and wedge of soil extending outward and upward at a rate of 1:2 (H:V) from the edge of the base extension. Assuming an effective unit weight of 58 pcf for base extension uplift resistance below groundwater.

10.3.3 LATERAL EARTH PRESSURES
Use the equivalent fluid weights (EFWs) shown in the table below for design of permanent structures. We assume in-place native materials with level backfill conditions.

Table 5: Soil Equivalent Fluid Weights
Condition Groundwater
Condition
Static EFW
(pcf)
Additional
Seismic EFW
(pcf)
At-Rest Above
Groundwater
67 30
Active 46 20
At-Rest Below
Groundwater
34 15
Active 23 10
The EFW values above were calculated using an average unit weight of approximately 125 pcf (63 pcf below groundwater) and an angle of internal friction (𝝓) of 28°. Include full hydrostatic pressure (buoyant + hydrostatic) for walls designed to be in services below the water table.

For static design, apply the resultant of the static at-rest earth pressure at a depth of 0.33H from the base of the wall where H equals the wall height. The at-rest earth pressure does not include a factor of safety.

We estimate the EFW for seismic loading using the Mononabe-Okabe equation. Apply the additional seismic pressures separately at a depth 0.5H from the base of the wall, where H equals the wall height. For seismic design, reduce the allowable passive pressure from 270 pcf to 150 pcf. We provided a general pressure diagram below.

Appendix B-19 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT (Revision 2) Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California February 3, 2023
14 For surcharge loads, apply an additional uniform lateral load behind the wall equivalent to the greater of 0.45-times the design surcharge pressure.

10.4 CONSTRUCTION CONSIDERATIONS

10.4.1 SHORING/TEMPORARY SLOPES
The contractor is responsible for the safety of all temporary excavations and must provide trench sloping and shoring design/construction in accordance with current CalOSHA requirements. In general, we encountered OSHA Type C soils at the site.

If temporary slopes are used in lieu of shoring, they must comply with OSHA standards.

10.4.2 DEWATERING
Based on the observed groundwater levels during our current and previous subsurface explorations and discussions with the WWTP personnel (see Section 5.3), groundwater was observed as high as elevation 565 ft. Therefore, groundwater may adversely affect the project Appendix B-20 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT (Revision 2) Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California February 3, 2023
15 during construction. The contractor will be responsible for designing and implementing a dewatering system to meet the requirements of the project. Dewatering operations will need to draw the groundwater down to a minimum of 3 ft below the planned excavation during construction.
11 RISK MANAGEMENT
Our experience and that of our profession clearly indicates that the risks of costly design, construction, and maintenance problems can be significantly lowered by retaining the Geotechnical Engineer of Record to provide additional services during design and construction.

For this project, Crawford should be retained as the Geotechnical Engineer of Record to:
• Review and provide comments on the civil plans and specifications prior to construction. • Observe foundation excavations.
• Update this report if design changes occur, 2 years or more lapse between this report and construction, and/or site conditions have changed.

If Crawford is not retained to perform the above applicable services, we are not responsible for any other party’s interpretation of our report, and subsequent addendums, letters, and discussions.
12 LIMITATIONS
Crawford performed services in accordance with generally accepted geotechnical engineering principles and practices currently used in this area. Do not use this report for different locations and/or projects without the written consent of Crawford. Where referenced, we used ASTM or Caltrans standards as a general (not strict) guideline only.

Crawford based this report on the current site conditions. We assumed the soil and groundwater conditions are representative of the subsurface conditions on the site. Actual conditions between explorations and other data points could be different.

Our scope did not include evaluation of on-site hazardous materials.

Logs of our explorations are presented in Appendix A. The lines designating the interface between soil types are approximate. The transition between soil types may be abrupt or gradual. Our recommendations are based on the final logs, which represent our interpretation of the field logs and general knowledge of the site and geological conditions.

Modern design and construction are complex, with many regulatory sources/restrictions, involved parties, construction alternatives, etc. It is common to experience changes and delays.

The owner should set aside a reasonable contingency fund based on complexities and cost estimates to cover changes and delays.

Appendix B-21 8660F10 April 2023

Appendix B-22 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT (Revision 2) Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California February 3, 2023

APPENDIX I
Figure 1 – Vicinity Map
Figure 2 – Exploration Location Map
Figure 3 – Geologic Map
Figure 4 – Fault Map

Appendix B-23 8660F10 April 2023

Appendix B-24 8660F10 April 2023

PROJECT

LOCATION
Prj. No:

Date:

City of Ukiah Recycled Water
Pipeline - Phase 4 Design Project
Ukiah, CA 19-503.1 NORTH
0' 3,000'
1"=3,000'
Figure 1
Vicinity Map
Source:

USGS 7.5' Topographic Maps, Elledge Peak
Quadrangle, Mendocino County, California, 2021,
1:24,000.
11/09/2022
Appendix B-25 8660F10 April 2023

Appendix B-26 8660F10 April 2023

Prj. No:

Date:

City of Ukiah Recycled Water
Pipeline - Phase 4 Design Project
Ukiah, CA
19-503.1 NORTH
Legend
CRAWFORD 2022

BORING LOCATION
CRAWFORD 2022

DCP LOCATION
CRAWFORD 2017

BORING LOCATION
LACO 2014

BORING LOCATION
Figure 2
Exploration
Location
Map
Source:

Basemap: AutoCAD Civil3D Geolocation Tool, using
Bing Maps
Topographic Data: Topographic Data provided by
Carollo via electronic transfer on 10/31/22.
11/09/2022
1"=50'
0' 50'
A-22-001
A-22-002
DCP-22-001
DCP-22-002
B-15
B2
B1
B-17
B-16
B-19
Appendix B-27 8660F10 April 2023

Appendix B-28 8660F10 April 2023

Prj. No: Date: 19-503.1 NORTH City of Ukiah Recycled Water Pipeline - Phase 4 Design Project Ukiah, CA Qal Alluvium Qt Quaternary nonmarine terrace deposits QP Plio-Pleistocene nonmarine Qc Description K Undivided Cretaceous marine KJf Franciscan Formation KJfv Franciscan Volcanic and metavolcanic rocks PROJECT LOCATION Figure 3 Geologic Map Source: Charles W. Jennings, Rudolph G Strand; Geologic Map of California, Ukiah Sheet; Olaf P. Jenkins Edition; 1:250,000; State of California, Department of Natural Resources; 1992. 11/09/2022 0' 10,000' 1"=10,000' Appendix B-29 8660F10 April 2023

Prj. No: Date: 19-503.1 NORTH City of Ukiah Recycled Water Pipeline - Phase 4 Design Project Ukiah, CA LEGEND Quaternary Fault (Age) <150 years <15,000 years <130,000 years <750,000 years <1.6 million years Location Well Constrained Moderately Constrained Inferred PROJECT LOCATION Figure 4 Fault Map Source: Basemap: National Geographic, Esri, Garmin, HERE, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, increment P Corp. Fault Data: USGS GIS Data 11/09/2022 1"=25,000' 0' 25,000' Maacama Fault Zone Unnamed Fault Clover Valley Fault Zone Bartlett Springs Fault System Wright Way Fault Collayomi Fault Zone Appendix B-30 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT (Revision 2) Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California February 3, 2023

APPENDIX II
2022 Crawford Boring Legend and Logs
2017 Crawford Boring Logs
2014 LACO Boring Logs
Appendix B-31 8660F10 April 2023

Appendix B-32 8660F10 April 2023

C Consolidation
CL Collapse Potential
CP Compaction Curve
CR Corrosion, Sulfates, Chlorides
CU Consolidated Undrained Triaxial
DR Drained Residual Shear Strength
DS Direct Shear
EI Expansion Index
M Moisture Content
OC Organic Content
P Permeability
PA Particle Size Analysis
PI Liquid Limit, Plastic Limit, Plasticity Index
PL Point Load Index
PM Pressure Meter
PP Pocket Penetrometer
R R-Value
SE Sand Equivalent
SG Specific Gravity
SW Swell Potential
TV Pocket Torvane
UC Unconfined Compression - Soil
Unconfined Compression - Rock
UU Unconsolidated Undrained Triaxial
UW Unit Weight
Appendix B-33 8660F10 April 2023

Appendix B-34 8660F10 April 2023

FIELD

ELEVATION
(ft)
580
579
578
577
576
575
574
573
572
571
570
569
568
567
566
565
564
563
562
561
560
559
558
557
556
555
554
553
552
551
550
549
548
DEPTH (ft)
1 2
3 4
5 6
7 8
9 10
11 12
13 14
15 16
17 18
19 20
21 22
23 24
25 26
27 28
29 30
31 32
33 SAMPLE

SAMPLE NO
Bulk
1 1
2 3
4 5
6 7
8 BLOWS
PER 6 IN.
9 7
9 3
5 12
8 5
12 7
7 3
8 16
9 6
16 6
2 4
12 20
12 10
BLOWS

PER FOOT
28 13
9 7
20 36
21 16
POCKET
PEN. (TSF)
+4.5
+4.5

4.00 1.50

GRAPHIC LOG

DESCRIPTION
SILTY SAND (SM); medium dense; tan/gray;
dry to moist; mostly fine SAND; little to some
low plasticity fines.

Lean CLAY with SAND (CL); hard; brown;
moist; mostly low plasticity fines; little fine
SAND.

CLAYEY SAND (SC); loose; gray; moist;
mostly fine SAND; some low plasticity fines.
moist to wet
medium dense; brown; moist
Lean CLAY (CL); very stiff; brown; moist;
mostly low plasticity fines; trace coarse to
fine SAND.

CLAYEY SAND with GRAVEL (SC); medium
dense; brown; wet; mostly coarse to fine
SAND; some low plasticity fines; few fine
GRAVEL.

Lean CLAY (CL); mostly low plasticity fines;
few fine SAND.

Bottom of borehole at 31.5 ft bgs
RECOVERY(%)
100
100
100
78 78
67 100
0 83
RQD (%)

LABORATORY

PLASTIC
LIMIT
20 23
19 LIQUID
LIMIT
31 38
28 MOISTURE
(%)

17.5 15.4

23.2 18.9
D. DENSITY
(PCF)
110.4
116.2
103.0
110.6
% PASSING
200 SIEVE
79 32
44 DRILL METHOD

CASING DEPTH

REMARKS
Embankment material
Corrosivity Analysis
Soil pH: 6.84
Min. Resistivity: 2,950
ohm-cm
Chloride: 4.8 ppm
Sulfate: 27.5 ppm
Redox Potential: (+) 212
mv
Sulfides Presence:

Negative
Tv = 1.34 tsf
Unconfined
Compressive Strength:
8050 psf
sand catcher
Tv = 0.875 tsf
little fine GRAVEL in
shoe
LOG OF BORING A-22-001
PROJECT NO: 19-503.1 BEGIN DATE: 09/30/2022 DRILLING CONTRACTOR: Geo-Ex Subsurface Exploration PROJECT: Ukiah Recycled Water Pipeline COMPLETION DATE: 09/30/2022 DRILLING METHOD: Solid-Stem Auger LOCATION: Ukiah, CA SURFACE ELEVATION: 581.0 (ft) DRILL RIG: D50 COUNTY: Mendocino SURFACE CONDITION: Soil HAMMER TYPE: Automatic; 140 (lbs); 30 (in) drop CLIENT: Carollo Engineers, Inc. WATER DEPTH: 21.0 ft SAMPLER TYPE & SIZE: MCAL (2.4" ID), SPT (1.4" ID), Bulk LOGGED BY: ABC READING TAKEN: 09/30/22 BOREHOLE DIAMETER: 4.0 (in) DEPTH OF BORING: 31.5 (ft) HAMMER EFFICIENCY: 101.9 (%) BACKFILL METHOD: Neat Cement Grout Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NO: 19-503.1
PROJECT: Ukiah Recycled Water Pipeline
BORING: A-22-001
ENTRY BY: OMR
CHECKED BY: ABC SHEET # 1 of 1
Appendix B-35 8660F10 April 2023

FIELD

ELEVATION
(ft)
576
575
574
573
572
571
570
569
568
567
566
565
564
563
562
561
560
559
558
557
556
555
554
553
552
551
550
549
DEPTH (ft)
1 2
3 4
5 6
7 8
9 10
11 12
13 14
15 16
17 18
19 20
21 22
23 24
25 26
27 28
SAMPLE

SAMPLE NO
1 2
3 4
5 6
BLOWS
PER 6 IN.
8 3
4 3
7 8
9 5
6 12
13 8
BLOWS

PER FOOT
13 400 psi
250 psi
20 22
13 POCKET
PEN. (TSF)

0.25 1.00

0.50 3.50

3.50 2.00

GRAPHIC LOG

DESCRIPTION
SILTY SAND (SM); medium dense; brown;
moist; mostly fine SAND; few fines.

Lean CLAY (CL); soft; gray; moist; mostly
low plasticity to medium plasticity fines.
stiff
medium stiff
very stiff
Bottom of borehole at 26.5 ft bgs
RECOVERY(%)
67 100
100
83 83
39 RQD (%)

LABORATORY

PLASTIC
LIMIT
25 LIQUID
LIMIT
43 MOISTURE
(%)

21.0 24.0
D. DENSITY
(PCF)
103.7
102.9
% PASSING
200 SIEVE
96 92

DRILL METHOD

CASING DEPTH

REMARKS
rig chatter at 2.5'
Tv = 0.4 tsf
Corrosivity Analysis
Soil pH: 7.05
Min. Resistivity: 1,470
ohm-cm
Chloride: 15.3 ppm
Sulfate: 31.6 ppm
concrete in sampler;
moved 5' north
Tv = 0.55 tsf
Tv = 0.5 tsf
Tv = 1.5 tsf
Unconfined
Compressive Strength:
6912 psf
Tv = 1.5 tsf
Tv = 0.625 tsf
LOG OF BORING A-22-002
PROJECT NO: 19-503.1 BEGIN DATE: 09/30/2022 DRILLING CONTRACTOR: Geo-Ex Subsurface Exploration PROJECT: Ukiah Recycled Water Pipeline COMPLETION DATE: 09/30/2022 DRILLING METHOD: Hollow-Stem Auger LOCATION: Ukiah, CA SURFACE ELEVATION: 577.0 (ft) DRILL RIG: D50 COUNTY: Mendocino SURFACE CONDITION: Soil HAMMER TYPE: Automatic; 140 (lbs); 30 (in) drop CLIENT: Carollo Engineers, Inc. WATER DEPTH: Not Encountered SAMPLER TYPE & SIZE: MCAL (2.4" ID), SH LOGGED BY: ABC READING TAKEN: N/A BOREHOLE DIAMETER: 6.0 (in) DEPTH OF BORING: 26.5 (ft) HAMMER EFFICIENCY: 101.9 (%) BACKFILL METHOD: Neat Cement Grout Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NO: 19-503.1
PROJECT: Ukiah Recycled Water Pipeline
BORING: A-22-002
ENTRY BY: OMR
CHECKED BY: ABC SHEET # 1 of 1
Appendix B-36 8660F10 April 2023

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Appendix B-37 8660F10 April 2023

16.5 SILTY SAND (SM) (continued).

Lean CLAY with SAND (CL); stiff; mottled brown and
gray; moist; about 15% coarse to fine GRAVEL;
about 15% fine SAND; about 70% medium plasticity,
medium toughness fines.

CLAYEY GRAVEL with SAND (GC); very dense;
brown; wet; about 60% coarse to fine GRAVEL; about
20% coarse to fine SAND; about 20% medium
plasticity fines.

Subangular to subrounded GRAVEL.

Bottom of borehole at 50.0 ft bgs
0 100
39 39
17 1.0 116.2
7 8
9 10
11 11
16 14
8 9
12 8
15 39
13 16
18 8
11 18
No sample recovery.

Chased with SPT sampler
to recover material with
about 67% recovery.

Sand catcher used,
sample disturbed.

Gravel chatter.

Sand catcher used,
sample disturbed.

Took a sample of the shoe
as the tubes looked like
sluff (Poorly graded
Gravel). Shoe was a clayey
gravel.

Loosing a lot of drilling
fluid.

Sand catcher used and
broke. Took a sample of
the shoe as the tubes
looked like sluff (Poorly
graded Gravel). Shoe was
a clayey gravel. Gravel
pieces were greater than 2
in.

The hole caved more than
2 ft.

The hole caved in 7 ft and
could not get sampler to
required depth.

FIELD LABORATORY
DEPTH ( ft)
PLASTICLIMITLIQUIDLIMITMOISTURE(%)

DESCRIPTION

ELEVATION
SAMPLESAMPLE NOPOCKETPEN. (TSF)GRAPHIC LOGRECOVERY(%)D. DENSITY(PCF) (ft)
BLOWSPER 6 IN.BLOWSPER FOOTRQD (%)DRILL METHODCASING DEPTH

REMARKS
% PASSING200 SIEVE
PROJECT: Ukiah WWTP CCB Replacement
PROJECT NUMBER: 17-414.1
ENTRY BY: KKL
SHEET 2 of 2
BORING: B1
CHECKED BY:

Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
30 21
54 34
29 26
27 28
29 30
31 32
33 34
35 36
37 38
39 40
41 42
43 44
45 46
47 48
49 50
51 52
53 54
55 Appendix B-38 8660F10 April 2023

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9/27/17
15 (ft)
Appendix B-39 8660F10 April 2023

SILTY SAND (SM) (continued).

Lean CLAY (CL); stiff; brown; moist; trace fine
GRAVEL; about 5% fine SAND; about 95% medium
plasticity fines.

Bottom of borehole at 26.5 ft bgs
89 1.5
7 6
9 14

FIELD LABORATORY
DEPTH ( ft)
PLASTICLIMITLIQUIDLIMITMOISTURE(%)

DESCRIPTION

ELEVATION
SAMPLESAMPLE NOPOCKETPEN. (TSF)GRAPHIC LOGRECOVERY(%)D. DENSITY(PCF) (ft)
BLOWSPER 6 IN.BLOWSPER FOOTRQD (%)DRILL METHODCASING DEPTH

REMARKS
% PASSING200 SIEVE
PROJECT: Ukiah WWTP CCB Replacement
PROJECT NUMBER: 17-414.1
ENTRY BY: KKL
SHEET 2 of 2
BORING: B2
CHECKED BY:

Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
23 26
27 28
29 30
31 32
33 34
35 36
37 38
39 40
41 42
43 44
45 46
47 48
49 50
51 52
53 54
55 Appendix B-40 8660F10 April 2023

WILDCAT DYNAMIC CONE LOG Page 1 of 1
Crawford & Associates, Inc.
1100 Corporate Way Suite 230 PROJECT NUMBER: 19-503.1
Sacramento, CA 95831 DATE STARTED: 09-22-2022
DATE COMPLETED: 09-22-2022
HOLE #: DCP-1 (Eastern Pond)
CREW: ABC/OMR SURFACE ELEVATION: 573
PROJECT: Ukiah WWTP Sludge Lagoon WATER ON COMPLETION: N/A ADDRESS: ( 39.111770°, -123.190679°) HAMMER WEIGHT: 35 lbs.

LOCATION: Ukiah, CA CONE AREA: 10 sq. cm

BLOWS RESISTANCE GRAPH OF CONE RESISTANCE TESTED CONSISTENCY DEPTH PER 10 cm Kg/cm² 0 50 100 150 N' NON-COHESIVE COHESIVE - 0 0.0 0 VERY LOOSE VERY SOFT
- 0 0.0 0 VERY LOOSE VERY SOFT
- 1 ft 0 0.0 0 VERY LOOSE VERY SOFT
- 0 0.0 0 VERY LOOSE VERY SOFT
- 0 0.0 0 VERY LOOSE VERY SOFT
- 2 ft 0 0.0 0 VERY LOOSE VERY SOFT
- 0 0.0 0 VERY LOOSE VERY SOFT
- 0 0.0 0 VERY LOOSE VERY SOFT
- 3 ft 0 0.0 0 VERY LOOSE VERY SOFT
- 1 m 0 0.0 0 VERY LOOSE VERY SOFT
- 0 0.0 0 VERY LOOSE VERY SOFT
- 4 ft 0 0.0 0 VERY LOOSE VERY SOFT
- 0 0.0 0 VERY LOOSE VERY SOFT
- 0 0.0 0 VERY LOOSE VERY SOFT
- 5 ft 0 0.0 0 VERY LOOSE VERY SOFT
- 0 0.0 0 VERY LOOSE VERY SOFT
- 0 0.0 0 VERY LOOSE VERY SOFT
- 6 ft 0 0.0 0 VERY LOOSE VERY SOFT
- 2 7.7 •• 2 VERY LOOSE SOFT
- 2 m 1 3.9 • 1 VERY LOOSE VERY SOFT
- 7 ft 14 47.9 ••••••••••••• 13 MEDIUM DENSE STIFF
- 23 78.7 •••••••••••••••••••••• 22 MEDIUM DENSE VERY STIFF - 14 47.9 ••••••••••••• 13 MEDIUM DENSE STIFF
- 8 ft 13 44.5 •••••••••••• 12 MEDIUM DENSE STIFF
- 10 34.2 ••••••••• 9 LOOSE STIFF
- 10 34.2 ••••••••• 9 LOOSE STIFF
- 9 ft 13 44.5 •••••••••••• 12 MEDIUM DENSE STIFF
- 13 44.5 •••••••••••• 12 MEDIUM DENSE STIFF
- 14 47.9 ••••••••••••• 13 MEDIUM DENSE STIFF
- 3 m 10 ft 15 51.3 •••••••••••••• 14 MEDIUM DENSE STIFF -
-
-
- 11 ft
-
-
- 12 ft
-
-
- 4 m 13 ft
19-503.1 Ukiah Recycled Water Pipeline
Appendix B-41 8660F10 April 2023

WILDCAT DYNAMIC CONE LOG Page 1 of 1
Crawford & Associates, Inc.
1100 Corporate Way Suite 230 PROJECT NUMBER: 19-503.1
Sacramento, CA 95831 DATE STARTED: 09-22-2022
DATE COMPLETED: 09-22-2022
HOLE #: DCP-2 (Western Pond)
CREW: ABC/OMR SURFACE ELEVATION: 573
PROJECT: Ukiah WWTP Sludge Lagoon WATER ON COMPLETION: N/A ADDRESS: ( 39.111694°, -123.191467°) HAMMER WEIGHT: 35 lbs.

LOCATION: Ukiah, CA CONE AREA: 10 sq. cm

BLOWS RESISTANCE GRAPH OF CONE RESISTANCE TESTED CONSISTENCY DEPTH PER 10 cm Kg/cm² 0 50 100 150 N' NON-COHESIVE COHESIVE - 0 0.0 0 VERY LOOSE VERY SOFT
- 0 0.0 0 VERY LOOSE VERY SOFT
- 1 ft 0 0.0 0 VERY LOOSE VERY SOFT
- 0 0.0 0 VERY LOOSE VERY SOFT
- 0 0.0 0 VERY LOOSE VERY SOFT
- 2 ft 0 0.0 0 VERY LOOSE VERY SOFT
- 0 0.0 0 VERY LOOSE VERY SOFT
- 0 0.0 0 VERY LOOSE VERY SOFT
- 3 ft 0 0.0 0 VERY LOOSE VERY SOFT
- 1 m 0 0.0 0 VERY LOOSE VERY SOFT
- 0 0.0 0 VERY LOOSE VERY SOFT
- 4 ft 0 0.0 0 VERY LOOSE VERY SOFT
- 0 0.0 0 VERY LOOSE VERY SOFT
- 0 0.0 0 VERY LOOSE VERY SOFT
- 5 ft 0 0.0 0 VERY LOOSE VERY SOFT
- 0 0.0 0 VERY LOOSE VERY SOFT
- 3 11.6 ••• 3 VERY LOOSE SOFT
- 6 ft 8 30.9 •••••••• 8 LOOSE MEDIUM STIFF
- 14 54.0 ••••••••••••••• 15 MEDIUM DENSE STIFF
- 2 m 12 46.3 ••••••••••••• 13 MEDIUM DENSE STIFF
- 7 ft 9 30.8 •••••••• 8 LOOSE MEDIUM STIFF
- 9 30.8 •••••••• 8 LOOSE MEDIUM STIFF
- 14 47.9 ••••••••••••• 13 MEDIUM DENSE STIFF
- 8 ft 16 54.7 ••••••••••••••• 15 MEDIUM DENSE STIFF
- 16 54.7 ••••••••••••••• 15 MEDIUM DENSE STIFF
- 20 68.4 ••••••••••••••••••• 19 MEDIUM DENSE VERY STIFF - 9 ft 19 65.0 •••••••••••••••••• 18 MEDIUM DENSE VERY STIFF - 18 61.6 ••••••••••••••••• 17 MEDIUM DENSE VERY STIFF
-
- 3 m 10 ft
-
-
-
- 11 ft
-
-
- 12 ft
-
-
- 4 m 13 ft
19-503.1 Ukiah Recycled Water Pipeline
Appendix B-42 8660F10 April 2023

579.5
574.5
565.5
SPT
B15-S1
SPT
B15-S2
MC
B15-S3
B15-S4
SPT
B15-S5
SPT
B15-S6
37 100
60 20-26-19
(45)
12-13-17
(30)
17-50
3-4-5
(9)
1-3-6
(9)
CL
GW
CH

7.5 12.5

21.5 (CL) Lean clay with sand (fill), dark to medium brown, fine sand, trace gravel, moist, low plasticity, hard.
(GW) Well graded gravel with sand, dark gray, trace fines, subangular to subrounded gravel, trace cobbles, moist, very dense.
(CH) Fat clay with sand, medium brown with dark gray mottling, fine sand, contains trace gravel, moist, stiff, medium to high plasticity. Light brown, saturated, and very sandy (fine to coarse) with no gravel below 17.5'.

Bottom of borehole at 21.5 feet.

LOGGED BY DAC
DRILLING METHOD Rotary Hollow Stem Auger
DRILLING CONTRACTOR Clear Heart Drilling GROUND WATER LEVELS:

CHECKED BY EAW
DATE STARTED 9/11/14 COMPLETED 9/11/14

AT END OF DRILLING ---
HOLE SIZE 6 inches

AT TIME OF DRILLING ---
GROUND ELEVATION 587 feet
NOTES Backfilled with neat cement grout ATD DEPTH (ft)
0 5
10 15
20 SAMPLE TYPE NUMBER
PROJECT NAME Ukiah Recycled Water
PROJECT LOCATION Ukiah, CA
CLIENT Carollo Engineers
PROJECT NUMBER 7986.00
PAGE 1 OF 1
BORING B-15 GENERAL BH / TP / WELL - GINT STD US LAB.GDT - 9/30/14 17:00 - P:\GINT FILES\PROJECTS\7986.00 UKIAH RECYCLED WATER.GPJ RECOVERY % BLOW COUNTS (N VALUE) U.S.C.S. GRAPHIC LOG

MATERIAL DESCRIPTION
Appendix B-43 8660F10 April 2023

583.0
578.5
564.5
MC
B16-S1
MC
B16-S2
B16-S3
SPT
B16-S4
SPT
B16-S5
SPT
B16-S6
83 83
100
6-10-16
(26)
12-14-26
(40)
4-4-6
(10)
6-10-17
(27)
12-17-19
(36)
ML
CL
CL

3.0 7.5

21.5 (ML) Sandy silt (fill), medium brown, contains trace gravel, moist, very stiff. (CL) Sandy lean clay with gravel, medium brown with dark gray mottling, fine to coarse rounded to subrounded gravel, moist, low to medium plasticity, very stiff.

Plasticity Index: 7.7
Direct Shear: C = 2300 psf, Phi = 21.3 degrees
(CL) Lean clay with sand and gravel, dark gray with trace light gray mottling, moist, medium plasticity, stiff. Very stiff with trace gravel below 12.5'. Hard below 17.5'.

Bottom of borehole at 21.5 feet.

LOGGED BY DAC
DRILLING METHOD Rotary Hollow Stem Auger
DRILLING CONTRACTOR Clear Heart Drilling GROUND WATER LEVELS:

CHECKED BY EAW
DATE STARTED 9/12/14 COMPLETED 9/12/14

AT END OF DRILLING ---
HOLE SIZE 6 inches

AT TIME OF DRILLING ---
GROUND ELEVATION 586 feet
NOTES Backfilled with neat cement grout ATD DEPTH (ft)
0 5
10 15
20 SAMPLE TYPE NUMBER
PROJECT NAME Ukiah Recycled Water
PROJECT LOCATION Ukiah, CA
CLIENT Carollo Engineers
PROJECT NUMBER 7986.00
PAGE 1 OF 1
BORING B-16 GENERAL BH / TP / WELL - GINT STD US LAB.GDT - 9/30/14 17:00 - P:\GINT FILES\PROJECTS\7986.00 UKIAH RECYCLED WATER.GPJ RECOVERY % BLOW COUNTS (N VALUE) U.S.C.S. GRAPHIC LOG

MATERIAL DESCRIPTION
Appendix B-44 8660F10 April 2023

568.5
563.5
554.5
MC
B17-S1
SPT
SPT
SPT
SPT
12-17-21
(38)
9-10-11
(21)
4-10-7
(17)
5-8-12
(20)
9-14-15
(29)
CL
CH
CL

7.5 12.5

21.5 (CL) Sandy lean clay with gravel (fill), medium brown, fine sand, fine to coarse subangular to subrounded gravel, moist, low plasticity, very stiff. Dark brown below 3'. Dark gray and stiff below

7.5'.
(CH) Fat clay with gravel (fill), dark gray with light gray and orange mottling, moist, medium plasticity, very stiff. Changes lighter brown 17.5'.
(CL) Lean clay, dark brown with dark gray and orange mottling, trace gravel, moist medium plasticity, very stiff.

Bottom of borehole at 21.5 feet.

LOGGED BY DAC
DRILLING METHOD Rotary Hollow Stem Auger
DRILLING CONTRACTOR Clear Heart Drilling GROUND WATER LEVELS:

CHECKED BY EAW
DATE STARTED 9/12/14 COMPLETED 9/12/14
AT END OF DRILLING 12.00 feet / Elevation 564.00 feet
HOLE SIZE 6 inches
AT TIME OF DRILLING 17.00 feet / Elevation 559.00 feet
GROUND ELEVATION 576 feet
NOTES Backfilled with neat cement grout ATD DEPTH (ft)
0 5
10 15
20 SAMPLE TYPE NUMBER
PROJECT NAME Ukiah Recycled Water
PROJECT LOCATION Ukiah, CA
CLIENT Carollo Engineers
PROJECT NUMBER 7986.00
PAGE 1 OF 1
BORING B-17 GENERAL BH / TP / WELL - GINT STD US LAB.GDT - 9/30/14 17:00 - P:\GINT FILES\PROJECTS\7986.00 UKIAH RECYCLED WATER.GPJ BLOW COUNTS (N VALUE) U.S.C.S. GRAPHIC LOG

MATERIAL DESCRIPTION
Appendix B-45 8660F10 April 2023

585.0
566.5
MC
B19-S1
MC
B19-S2
B19-S3
SPT
B19-S4
SPT
B19-S5
SPT
B19-S6
30-22-24
(46)
18-20-28
(48)
3-3-8
(11)
4-9-14
(23)
10-12-14
(26)
CL
CL

3.0 21.5
(CL) Gravelly clay with sand (fill), dark brown to dark purple gray, fine sand, fine to coarse subangular to subround gravel, moist, very dense.
(CL) Lean clay with gravel and sand, medium brown to dark gray with orange mottling, fine to coarse subangular to subrounded gravel, moist, low plasticity, hard. Dark gray to black and stiff below 7.5'. Bluish gray between 12.5' and 15.75'. Sand is fine to coarse below 12.5'. Light to medium brown and very stiff with less gravel below 15.75'.

Plasticity Index: 7.5
Direct Shear: C = 2225 psf, Phi = 34.2 degrees
Bottom of borehole at 21.5 feet.

LOGGED BY DAC
DRILLING METHOD Rotary Hollow Stem Auger
DRILLING CONTRACTOR Clear Heart Drilling GROUND WATER LEVELS:

CHECKED BY EAW
DATE STARTED 9/11/14 COMPLETED 9/11/14

AT END OF DRILLING ---
HOLE SIZE 6 inches

AT TIME OF DRILLING ---
GROUND ELEVATION 588 feet
NOTES Backfilled with neat cement grout ATD DEPTH (ft)
0 5
10 15
20 SAMPLE TYPE NUMBER
PROJECT NAME Ukiah Recycled Water
PROJECT LOCATION Ukiah, CA
CLIENT Carollo Engineers
PROJECT NUMBER 7986.00
PAGE 1 OF 1
BORING B-19 GENERAL BH / TP / WELL - GINT STD US LAB.GDT - 9/30/14 17:00 - P:\GINT FILES\PROJECTS\7986.00 UKIAH RECYCLED WATER.GPJ BLOW COUNTS (N VALUE) U.S.C.S. GRAPHIC LOG

MATERIAL DESCRIPTION
Appendix B-46 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT (Revision 2) Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California February 3, 2023

APPENDIX III
Laboratory Test Results
Hazardous Materials Laboratory Results
Appendix B-47 8660F10 April 2023

Appendix B-48 8660F10 April 2023

Project Name:

CAInc File No: 19-503.1
Date: 10/21/22
Technician: AC/LAD/KVL
1 2 3 4 5
USCS Symbol CL SC CL CL CL
Depth (ft.) 6 11 16 21 6
Sample Length (in.) 5.333 4.524 5.908 4.820 5.686
Diameter (in.) 2.399 2.398 2.399 2.393 2.394
Sample Volume (ft3) 0.01395 0.01182 0.01545 0.01255 0.01481 Total Mass Soil+Tube (g) 1100.1 993.0 1165.7 748.2 1121.3 Mass of Tube (g) 279.1 274.1 276.0 0.0 278.5
Tare No. B3 2036 G12 C15 B19
Tare (g) 13.7 124.2 13.4 13.7 13.6
Wet Soil + Tare (g) 66.0 459.9 72.1 61.5 61.3
Dry Soil + Tare (g) 58.2 415.0 61.0 53.9 53.0
Dry Soil (g) 44.5 290.8 47.7 40.2 39.4
Water (g) 7.8 44.9 11.1 7.6 8.3
Moisture (%) 17.5 15.4 23.2 18.9 21.0
Dry Density (pcf) 110.4 116.2 103.0 110.6 103.7
Notes:

City of Ukiah Recycled Water Pipeline - Phase 4 Design Project MOISTURE-DENSITY TESTS - D2216/D7263
Sample No. A-22-001-
3A
A-22-001-
4A
A-22-001-
5A
A-22-001-
6A
A-22-002-
1A
Appendix B-49 8660F10 April 2023

Project Name:

CAInc File No: 19-503.1
Date: 10/21/22
Technician: AC/LAD/KVL
1 2 3 4 5
USCS Symbol CL CL
Depth (ft.) 10 16
Sample Length (in.) 6.494 5.620
Diameter (in.) 2.838 2.390
Sample Volume (ft3) 0.02376 0.01459
Total Mass Soil+Tube (g) 1800.0 844.8
Mass of Tube (g) 455.0 0.0
Tare No. G11 C7
Tare (g) 13.4 13.7
Wet Soil + Tare (g) 81.4 60.0
Dry Soil + Tare (g) 66.9 51.1
Dry Soil (g) 53.5 37.4
Water (g) 14.5 9.0
Moisture (%) 27.1 24.0
Dry Density (pcf) 98.2 102.9
Notes:

City of Ukiah Recycled Water Pipeline - Phase 4 Design Project MOISTURE-DENSITY TESTS - D2216/D7263
Sample No. A-22-002- 3 A-22-002-
4A
Appendix B-50 8660F10 April 2023

Project Name: City of Ukiah Recycled Water Pipeline - Phase 4 Design Project CAInc File No: 19-503.1
Date: 10/31/22
Technician: CAP
Method A
Max Particle
Size (100%
Passing)
Standard Sieve
Size
Recommended
Min Mass of
Test
Specimens
2 mm or less No. 10 20 g

4.75 mm No. 4 100 g

9.5 mm 3/8 " 500 g

19.0 mm 3/4 " 2.5 kg

37.5 mm 1 1/2 " 10 kg

75.0 mm 3 " 50 kg
Sample No. A-22-001-2 A-22-001-4A A-22-001-7A A-22-002-4B A-22-002-6A USCS Symbol CL SC SC CL CL
Depth (ft.) 5 11 26 15.5 26
Tare No. 1016 2030 1002 3020 X21
Tare (g) 126.7 124.2 125.6 121.9 114.7
Dry Soil + Tare (g) 310 415 473.2 343.1 321.5
Dry Mass before (g) 183.3 290.8 347.6 221.2 206.8
Dry Mass after (g) 38.2 197.6 194.5 8.4 16.7
Percent Fines (%) 79 32 44 96 92
Notes:
200 Wash - ASTM D1140
Table from 6.2 of ASTM D1140
Appendix B-51 8660F10 April 2023

City of Ukiah Recycled Water Pipeline
19-503.1
11/10/22
zzz
A-22-001-Bulk
Depth (ft): 0-2.5
% Fines
Coarse Fine Coarse Medium Fine Silt/Clay
7 7 4 6 19
0 57
Sieve # Opening Cummulative % Passing
mm Mass Retained (g) %
3" 75 0.0 100%
2" 50 0.0 100%
1-1/2" 37.5 0.0 100%
1" 25.0 54.7 94%
3/4" 19.0 65.5 93%
1/2" 12.5 80.7 92%
3/8" 9.50 90.0 91%
#4 4.75 131.6 86%
#10 2.00 171.3 82%
#20 0.825 205.8 79%
#40 0.425 234.9 76%
#60 0.250 271.5 72%
#100 0.150 329.3 66%
#200 0.075 422.4 57%
Cu = NA Cc = NA
Fine
Coefficient of Uniformity Coefficient of Curvature
Cobbles
Coarse
Gravel
Sand
Coarse
Fine
Medium
14 29
Silt/Clay
% Gravel % Sand
ASTM 6913 - Method A
Project Name:

Technician:
% Cobble
CAInc File No:

Date:

Sample ID:

USCS Classification: Sandy Silt (ML)
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
100 10 1 0.1 0.01
Percent Passing by Weight
Grain Size (mm)
Particle Size Distribution
Appendix B-52 8660F10 April 2023

City of Ukiah Recycled Water Pipeline
19-503.1
11/10/22
zzz
A-22-002-1B
Depth (ft): 5.5
% Fines
Coarse Fine Coarse Medium Fine Silt/Clay
0 0 1 11 28
0 60
Sieve # Opening Cummulative % Passing
mm Mass Retained (g) %
3" 75 0.0 100%
2" 50 0.0 100%
1-1/2" 37.5 0.0 100%
1" 25.0 0.0 100%
3/4" 19.0 0.0 100%
1/2" 12.5 0.0 100%
3/8" 9.50 0.0 100%
#4 4.75 0.1 100%
#10 2.00 2.9 99%
#20 0.825 15.1 93%
#40 0.425 27.8 88%
#60 0.250 38.8 83%
#100 0.150 61.4 73%
#200 0.075 89.5 60%
Cu = NA Cc = NA
Sample ID:

USCS Classification: Sandy Silt (ML)
CAInc File No:

Date:
% Gravel % Sand
ASTM 6913 - Method A
Project Name:

Technician:
% Cobble
Fine
Coefficient of Uniformity Coefficient of Curvature
Cobbles
Coarse
Gravel
Sand
Coarse
Fine
Medium
0 40
Silt/Clay
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
100 10 1 0.1 0.01
Percent Passing by Weight
Grain Size (mm)
Particle Size Distribution
Appendix B-53 8660F10 April 2023

Project Name: Ukiah WWTP Sludge Pond Sampled By: Client Project No. : 220328 (19-503.1) Date Sampled: 10/21/2022 Client: Crawford & Associates Sample: 2A
Lab Number: L223499 Depth: 5 - 7.5 ft.

Sample Description: CL

PLASTIC LIMIT LIQUID LIMIT
TEST NO. 1 2 1 2 3 4
Number of Blows [N] 32 25 18
Container No. A B C D E
Wet Wt. of Soil + Cont.(gm) 23.83 23.76 42.01 43.62 44.39 Dry Wt. of Soil + Cont. (gm) 23.33 23.27 37.06 38.15 38.60 Weight of Container (gm) 20.83 20.78 20.80 20.70 20.94
Weight of Water (gm) 0.50 0.49 4.95 5.47 5.79
Weight of Dry Soil (gm) 2.50 2.49 16.26 17.45 17.66
Moisture Content (%) [Wn] 20.0 19.7 30.4 31.3 32.8

PROCEDURES USED
Wet Preparation x
x Dry Preparation
31 20
Plasticity Index 12
PI at "A" - Line = 0.73(LL-20) =
One - Point Liquid Limit Calculation
LL =Wn(N/25)
Wt. Ret. #40
Wt. Total Smpl.
% Ret. #40
Plastic and Liquid Limits of Soils
Liquid Limit
Plastic Limit
USCS Classification
ASTM D4318
Procedure A Procedure B
(Single Point) (Multi-Point)

0.121

0.0 5.0

10.0 15.0

20.0 25.0

30.0 35.0

40.0 45.0

50.0 0 10 20 30
Moisture Content (%)
Number of Blows
Appendix B-54 8660F10 April 2023

Project Name: Ukiah WWTP Sludge Pond Sampled By: Client Project No. : 220328 (19-503.1) Date Sampled: 10/21/2022 Client: Crawford & Associates Sample: 5A
Lab Number: L223499 Depth: 16 - 16.5 ft.

Sample Description: CL

PLASTIC LIMIT LIQUID LIMIT
TEST NO. 1 2 1 2 3 4
Number of Blows [N] 29 25 18
Container No. A B C D E
Wet Wt. of Soil + Cont.(gm) 23.80 23.75 47.05 47.79 48.82 Dry Wt. of Soil + Cont. (gm) 23.23 23.18 39.89 40.37 40.90 Weight of Container (gm) 20.72 20.64 20.63 20.69 20.84
Weight of Water (gm) 0.57 0.57 7.16 7.42 7.92
Weight of Dry Soil (gm) 2.51 2.54 19.26 19.68 20.06
Moisture Content (%) [Wn] 22.7 22.4 37.2 37.7 39.5

PROCEDURES USED
Wet Preparation x
x Dry Preparation
38 23
Plasticity Index 15
PI at "A" - Line = 0.73(LL-20) =
One - Point Liquid Limit Calculation
LL =Wn(N/25)
Wt. Ret. #40
Wt. Total Smpl.
% Ret. #40
Liquid Limit
Plastic Limit
USCS Classification
ASTM D4318
Procedure A Procedure B
(Single Point) (Multi-Point)
Plastic and Liquid Limits of Soils

0.121

0.0 5.0

10.0 15.0

20.0 25.0

30.0 35.0

40.0 45.0

50.0 0 10 20 30
Moisture Content (%)
Number of Blows
Appendix B-55 8660F10 April 2023

Project Name: Ukiah WWTP Sludge Pond Sampled By: Client Project No. : 220328 (19-503.1) Date Sampled: 10/21/2022 Client: Crawford & Associates Sample: 8A
Lab Number: L223499 Depth: 30 - 31.5 ft.

Sample Description: CL

PLASTIC LIMIT LIQUID LIMIT
TEST NO. 1 2 1 2 3 4
Number of Blows [N] 31 23 19
Container No. A B C D E
Wet Wt. of Soil + Cont.(gm) 23.73 23.62 40.55 43.43 45.22 Dry Wt. of Soil + Cont. (gm) 23.27 23.15 36.30 38.43 39.69 Weight of Container (gm) 20.82 20.67 20.93 20.84 20.74
Weight of Water (gm) 0.46 0.47 4.25 5.00 5.53
Weight of Dry Soil (gm) 2.45 2.48 15.37 17.59 18.95
Moisture Content (%) [Wn] 18.8 19.0 27.7 28.4 29.2

PROCEDURES USED
Wet Preparation x
x Dry Preparation
28 19
Plasticity Index 9
PI at "A" - Line = 0.73(LL-20) =
One - Point Liquid Limit Calculation
LL =Wn(N/25)
Wt. Ret. #40
Wt. Total Smpl.
% Ret. #40
Liquid Limit
Plastic Limit
USCS Classification
ASTM D4318
Procedure A Procedure B
(Single Point) (Multi-Point)
Plastic and Liquid Limits of Soils

0.121

0.0 5.0

10.0 15.0

20.0 25.0

30.0 35.0

40.0 45.0

50.0 0 10 20 30
Moisture Content (%)
Number of Blows
Appendix B-56 8660F10 April 2023

Project Name: Ukiah WWTP Sludge Pond Sampled By: Client Project No. : 220328 (19-503.1) Date Sampled: 10/21/2022 Client: Crawford & Associates Sample: 4A
Lab Number: L223499 Depth: 16 - 16.5 ft.

Sample Description: CL

PLASTIC LIMIT LIQUID LIMIT
TEST NO. 1 2 1 2 3 4
Number of Blows [N] 35 30 23
Container No. A B C D E
Wet Wt. of Soil + Cont.(gm) 23.54 23.54 37.02 42.48 48.51 Dry Wt. of Soil + Cont. (gm) 22.99 22.96 32.31 35.89 39.94 Weight of Container (gm) 20.70 20.65 20.69 20.49 20.80
Weight of Water (gm) 0.55 0.58 4.71 6.59 8.57
Weight of Dry Soil (gm) 2.29 2.31 11.62 15.40 19.14
Moisture Content (%) [Wn] 24.0 25.1 40.5 42.8 44.8

PROCEDURES USED
Wet Preparation x
x Dry Preparation
43 25
Plasticity Index 19
PI at "A" - Line = 0.73(LL-20) =
One - Point Liquid Limit Calculation
LL =Wn(N/25)
Wt. Ret. #40
Wt. Total Smpl.
% Ret. #40
Liquid Limit
Plastic Limit
USCS Classification
ASTM D4318
Procedure A Procedure B
(Single Point) (Multi-Point)
Plastic and Liquid Limits of Soils

0.121

0.0 5.0

10.0 15.0

20.0 25.0

30.0 35.0

40.0 45.0

50.0 0 10 20 30
Moisture Content (%)
Number of Blows
Appendix B-57 8660F10 April 2023

Project Name:

CAInc File No: 19-503.1
Date: 10/21/22
Technician: LAD
Sample ID: A-22-001-6A Depth (ft): 21.0
USCS Classification: Lean Clay (CL)
Dry Density (pcf) 110.6
Water Content (%) 18.9
Unconfined Compressive
Strength (psi) 55.9
Unconfined Compressive
Strength (psf) 8050
Average Height (in) 4.820
Average Diameter (in) 2.393
Rate of strain (%) 0.7
Strain at Failure (%) 10.8
Notes:

City of Ukiah Recycled Water Pipeline - Phase 4 Design Project UNCONFINED COMPRESSION TEST - D2166

0.0 10.0

20.0 30.0

40.0 50.0

60.0 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0
Compressive Strength (psi)
Axial Strain (%)
Appendix B-58 8660F10 April 2023

Project Name:

CAInc File No: 19-503.1
Date: 10/21/22
Technician: LAD
Sample ID: A-22-002-4A Depth (ft): 16.0
USCS Classification: Lean Clay (CL)
Dry Density (pcf) 102.9
Water Content (%) 24.0
Unconfined Compressive
Strength (psi) 48.0
Unconfined Compressive
Strength (psf) 6912
Average Height (in) 5.620
Average Diameter (in) 2.390
Rate of strain (%) 0.7
Strain at Failure (%) 10.2
Notes:

City of Ukiah Recycled Water Pipeline - Phase 4 Design Project UNCONFINED COMPRESSION TEST - D2166

0.0 10.0

20.0 30.0

40.0 50.0

60.0 0.0 2.0 4.0 6.0 8.0 10.0 12.0
Compressive Strength (psi)
Axial Strain (%)
Appendix B-59 8660F10 April 2023

Appendix B-60 8660F10
April 2023

Appendix B-61 8660F10
April 2023

Summary of Chemical Analytical Data
Ukiah Recycled Water Pipeline - Phase 4 Design Project
Project 19-503.1
Sample ID: A-22-002-2
Date collected: 9/30/22
Date Analyzed: 10/25/22
Volatile Organics - EPA Method 8260B
Concentration
(mg/kg)
Tetrachloroethene 0.011
Toluene 0.0051
Xylenes 0.0016 J
Purgeable Aromatics and Total Petroleum Hydrocarbons (EPA Method 8015B) Concentration
(mg/kg)
GRO (C4-C12) 0.78 J
Metals - Total Concentrations (EPA Methods 6010,7471A)
Concentration TTLC STLC 10X STLC
(mg/kg) (mg/kg) (mg/l) (mg/l)
Antimony 7.8 J 500 15 150
Arsenic 5.7 J 50 5 50
Barium 410 10,000 100 1,000
Berylliuym <0.47 75 0.75 7.5
Cadmium 0.88 J 100 1 10
Chromium 47 2,500 5 50
Cobalt 5.2 J 8,000 80 800
Copper 280 2,500 25 250
Lead 26 1,000 5 50
Mercury 1.1 J 20 0.2 2
Molybdenum 0.8 3,500 350 3,500
Nickel 33 2,000 20 200
Selenium <9.8 100 1 10
Silver 13 500 5 50
Tahllium <6.4 700 7 70
Vanadiam 29 2,400 24 240
Zinc 1,300 5,000 250 2,500
Explanation
J - estimated value
mg/kg - milligram/kilogram
mg/l - milligram/liter
TTLC - Total Threshold Limit Concentration
STLC - Soluble Threshold Limit Concentration
Appendix B-62 8660F10 April 2023

Date of Report: 11/03/2022
Armando Castro
Crawford & Associates, Inc.
4701 Freeport Blvd
Sacramento, CA 95822
Client Project: 19-503.1 WWTP Sludge Pod
BCL Project:

BCL Work Order:

Enclosed are the results of analyses for samples received by the laboratory on 10/26/2022. If you have any questions concerning this report, please feel free to contact me.

Invoice ID:
2225679
Sludge
B462077
Contact Person: Vanessa Sandoval
Sincerely,
Client Service Rep
Stuart Buttram
Operations Manager
Certifications: CA ELAP #1186; NV #CA00014; OR ELAP #4032-001; AK UST101 The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 1 of 23 Appendix B-63 8660F10 April 2023

Table of Contents
Sample Information
Chain of Custody and Cooler Receipt form.............................................................................................................................................. 3 Laboratory / Client Sample Cross Reference........................................................................................................................................... 6 Sample Results
2225679-01 - LEAN CLAY TRANSITION FROM SEWAGE SLUDGE
Volatile Organic Analysis (EPA Method 8260B)........................................................................................................................ 7 Purgeable Aromatics and Total Petroleum Hydrocarbons........................................................................................................ 10 Total Concentrations (TTLC)..................................................................................................................................................... 11 Quality Control Reports
Volatile Organic Analysis (EPA Method 8260B)
Method Blank Analysis.............................................................................................................................................................. 12 Laboratory Control Sample........................................................................................................................................................ 14 Precision and Accuracy.............................................................................................................................................................. 15 Purgeable Aromatics and Total Petroleum Hydrocarbons
Method Blank Analysis.............................................................................................................................................................. 16 Laboratory Control Sample........................................................................................................................................................ 17 Precision and Accuracy.............................................................................................................................................................. 18 Total Concentrations (TTLC)
Method Blank Analysis.............................................................................................................................................................. 19 Laboratory Control Sample........................................................................................................................................................ 20 Precision and Accuracy.............................................................................................................................................................. 21 Notes
Notes and Definitions................................................................................................................................................................ 23 The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 2 of 23 Appendix B-64 8660F10 April 2023

Chain of Custody and Cooler Receipt Form for 2225679 Page 1 of 3 The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 3 of 23 Appendix B-65 8660F10 April 2023

Chain of Custody and Cooler Receipt Form for 2225679 Page 2 of 3 The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 4 of 23 Appendix B-66 8660F10 April 2023

Chain of Custody and Cooler Receipt Form for 2225679 Page 3 of 3 The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 5 of 23 Appendix B-67 8660F10 April 2023

Crawford & Associates, Inc.
4701 Freeport Blvd
Sacramento, CA 95822
Project:

Project Number:

Project Manager:

Sludge
19-503.1 WWTP Sludge Pod
Armando Castro
Reported: 11/03/2022 15:30
Laboratory / Client Sample Cross Reference
Laboratory Client Sample Information
2225679-01
Sampling Point:

Sampling Location:

Project Number:

COC Number: ---
---
--- LEAN CLAY TRANSITION FROM SEWAGE SLUDGE
Receive Date:

Sampling Date:

Sample Depth:

Lab Matrix: --- 10/26/2022 09:49
09/30/2022 12:00
Solids
Sampled By: Shelby Tube Sample Type: Soil
The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 6 of 23 Appendix B-68 8660F10 April 2023

Crawford & Associates, Inc.
4701 Freeport Blvd
Sacramento, CA 95822
Project:

Project Number:

Project Manager:

Sludge
19-503.1 WWTP Sludge Pod
Armando Castro
Reported: 11/03/2022 15:30
BCL Sample ID: 2225679-01 Client Sample Name:

Constituent Result Units Method Bias Quals
MB Lab
Volatile Organic Analysis (EPA Method 8260B)
DCN
LEAN CLAY TRANSITION FROM SEWAGE SLUDGE, 9/30/2022 12:00:00PM, Shelby Tube

PQL MDL
Benzene ND mg/kg 0.0050 0.00067 EPA-8260B ND A26 1
Bromobenzene ND mg/kg 0.0050 0.00087 EPA-8260B ND A26 1 Bromochloromethane ND mg/kg 0.0050 0.00081 EPA-8260B ND A26 1 Bromodichloromethane ND mg/kg 0.0050 0.00078 EPA-8260B ND A26 1 Bromoform ND mg/kg 0.0050 0.00070 EPA-8260B ND A26 1
Bromomethane ND mg/kg 0.0050 0.0017 EPA-8260B ND A26 1
n-Butylbenzene ND mg/kg 0.0050 0.00076 EPA-8260B ND A26 1 sec-Butylbenzene ND mg/kg 0.0050 0.00071 EPA-8260B ND A26 1 tert-Butylbenzene ND mg/kg 0.0050 0.00085 EPA-8260B ND A26 1 Carbon tetrachloride ND mg/kg 0.0050 0.00078 EPA-8260B ND A26 1 Chlorobenzene ND mg/kg 0.0050 0.00077 EPA-8260B ND A26 1 Chloroethane ND mg/kg 0.0050 0.0011 EPA-8260B ND A26 1
Chloroform ND mg/kg 0.0050 0.00090 EPA-8260B ND A26 1
Chloromethane ND mg/kg 0.0050 0.0011 EPA-8260B ND A26 1 2-Chlorotoluene ND mg/kg 0.0050 0.00087 EPA-8260B ND A26 1 4-Chlorotoluene ND mg/kg 0.0050 0.00070 EPA-8260B ND A26 1 Dibromochloromethane ND mg/kg 0.0050 0.00080 EPA-8260B ND A26 1 1,2-Dibromo-3-chloropropane ND mg/kg 0.0050 0.00096 EPA-8260B ND A26 1 1,2-Dibromoethane ND mg/kg 0.0050 0.00082 EPA-8260B ND A26 1 Dibromomethane ND mg/kg 0.0050 0.0014 EPA-8260B ND A26 1 1,2-Dichlorobenzene ND mg/kg 0.0050 0.00079 EPA-8260B ND A26 1 1,3-Dichlorobenzene ND mg/kg 0.0050 0.00073 EPA-8260B ND A26 1 1,4-Dichlorobenzene ND mg/kg 0.0050 0.00073 EPA-8260B ND A26 1 Dichlorodifluoromethane ND mg/kg 0.0050 0.00079 EPA-8260B ND A26 1 1,1-Dichloroethane ND mg/kg 0.0050 0.00064 EPA-8260B ND A26 1 1,2-Dichloroethane ND mg/kg 0.0050 0.00073 EPA-8260B ND A26 1 1,1-Dichloroethene ND mg/kg 0.0050 0.0011 EPA-8260B ND A26 1 cis-1,2-Dichloroethene ND mg/kg 0.0050 0.00054 EPA-8260B ND A26 1 trans-1,2-Dichloroethene ND mg/kg 0.0050 0.0037 EPA-8260B ND A26 1 1,2-Dichloropropane ND mg/kg 0.0050 0.00080 EPA-8260B ND A26 1 1,3-Dichloropropane ND mg/kg 0.0050 0.00067 EPA-8260B ND A26 1 2,2-Dichloropropane ND mg/kg 0.0050 0.00067 EPA-8260B ND A26 1 1,1-Dichloropropene ND mg/kg 0.0050 0.00067 EPA-8260B ND A26 1 The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 7 of 23 Appendix B-69 8660F10 April 2023

Crawford & Associates, Inc.
4701 Freeport Blvd
Sacramento, CA 95822
Project:

Project Number:

Project Manager:

Sludge
19-503.1 WWTP Sludge Pod
Armando Castro
Reported: 11/03/2022 15:30
BCL Sample ID: 2225679-01 Client Sample Name:

Constituent Result Units Method Bias Quals
MB Lab
Volatile Organic Analysis (EPA Method 8260B)
DCN
LEAN CLAY TRANSITION FROM SEWAGE SLUDGE, 9/30/2022 12:00:00PM, Shelby Tube

PQL MDL
cis-1,3-Dichloropropene ND mg/kg 0.0050 0.00058 EPA-8260B ND A26 1 trans-1,3-Dichloropropene ND mg/kg 0.0050 0.00066 EPA-8260B ND A26 1 Ethylbenzene ND mg/kg 0.0050 0.00069 EPA-8260B ND A26 1 Hexachlorobutadiene ND mg/kg 0.0050 0.00067 EPA-8260B ND A26 1 Isopropylbenzene ND mg/kg 0.0050 0.00080 EPA-8260B ND A26 1 p-Isopropyltoluene ND mg/kg 0.0050 0.00059 EPA-8260B ND A26 1 Methylene chloride ND mg/kg 0.010 0.0011 EPA-8260B ND A26 1 Methyl t-butyl ether ND mg/kg 0.0050 0.00056 EPA-8260B ND A26 1 Naphthalene ND mg/kg 0.0050 0.00099 EPA-8260B ND A26 1
n-Propylbenzene ND mg/kg 0.0050 0.00071 EPA-8260B ND A26 1 Styrene ND mg/kg 0.0050 0.00062 EPA-8260B ND A26 1
1,1,1,2-Tetrachloroethane ND mg/kg 0.0050 0.00095 EPA-8260B ND A26 1 1,1,2,2-Tetrachloroethane ND mg/kg 0.0050 0.00084 EPA-8260B ND A26 1 Tetrachloroethene 0.011 mg/kg 0.0050 0.00097 EPA-8260B ND A26 1 Toluene 0.0051 mg/kg 0.0050 0.00069 EPA-8260B ND A26 1
1,2,3-Trichlorobenzene ND mg/kg 0.0050 0.0015 EPA-8260B ND A26 1 1,2,4-Trichlorobenzene ND mg/kg 0.0050 0.0014 EPA-8260B ND A26 1 1,1,1-Trichloroethane ND mg/kg 0.0050 0.00067 EPA-8260B ND A26 1 1,1,2-Trichloroethane ND mg/kg 0.0050 0.00094 EPA-8260B ND A26 1 Trichloroethene ND mg/kg 0.0050 0.00074 EPA-8260B ND A26 1 Trichlorofluoromethane ND mg/kg 0.0050 0.0015 EPA-8260B ND A26 1 1,2,3-Trichloropropane ND mg/kg 0.0050 0.0019 EPA-8260B ND A26 1 1,1,2-Trichloro-1,2,2-trifluoroethane ND mg/kg 0.0050 0.0010 EPA-8260B ND A26 1 1,2,4-Trimethylbenzene ND mg/kg 0.0050 0.00080 EPA-8260B ND A26 1 1,3,5-Trimethylbenzene ND mg/kg 0.0050 0.00066 EPA-8260B ND A26 1 Vinyl chloride ND mg/kg 0.0050 0.00059 EPA-8260B ND A26 1 Total Xylenes ND mg/kg 0.010 0.0025 EPA-8260B ND A26 1
p- & m-Xylenes 0.0016 mg/kg 0.0050 0.0015 EPA-8260B ND J,A26 1 o-Xylene ND mg/kg 0.0050 0.00093 EPA-8260B ND A26 1
1,2-Dichloroethane-d4 (Surrogate) 113 % 70 - 121 (LCL - UCL) EPA-8260B 1 Toluene-d8 (Surrogate) 88.0 % 81 - 117 (LCL - UCL) EPA-8260B 1 4-Bromofluorobenzene (Surrogate) 80.4 % 74 - 121 (LCL - UCL) EPA-8260B 1 The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 8 of 23 Appendix B-70 8660F10 April 2023

Crawford & Associates, Inc.
4701 Freeport Blvd
Sacramento, CA 95822
Project:

Project Number:

Project Manager:

Sludge
19-503.1 WWTP Sludge Pod
Armando Castro
Reported: 11/03/2022 15:30
BCL Sample ID: 2225679-01 Client Sample Name:

Method Prep Date Date/Time
Run
Analyst Instrument Dilution Batch ID
QC
Volatile Organic Analysis (EPA Method 8260B)
DCN
LEAN CLAY TRANSITION FROM SEWAGE SLUDGE, 9/30/2022 12:00:00PM, Shelby Tube 1 EPA-8260B 10/27/22 11:30 10/27/22 17:34 EAB MS-V17 1 B152390 EPA 5030 Soil MS DCN = Data Continuation Number
The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 9 of 23 Appendix B-71 8660F10 April 2023

Crawford & Associates, Inc.
4701 Freeport Blvd
Sacramento, CA 95822
Project:

Project Number:

Project Manager:

Sludge
19-503.1 WWTP Sludge Pod
Armando Castro
Reported: 11/03/2022 15:30
BCL Sample ID: 2225679-01 Client Sample Name:

Constituent Result Units Method Bias Quals
MB Lab
Purgeable Aromatics and Total Petroleum Hydrocarbons
DCN
LEAN CLAY TRANSITION FROM SEWAGE SLUDGE, 9/30/2022 12:00:00PM, Shelby Tube

PQL MDL
Gasoline Range Organics (C4 - C12) 0.78 mg/kg 1.0 0.20 EPA-8015B ND J,A26 1 a,a,a-Trifluorotoluene (FID Surrogate) 50.0 % 70 - 130 (LCL - UCL) EPA-8015B A20,S09 1 QC
Date/Time Analyst Instrument Dilution Batch ID
Run
DCN Method Prep Date Prep Method
1 EPA-8015B 10/27/22 08:37 10/27/22 12:36 SEM GC-V8 1 B152311 EPA 5030 Soil GC DCN = Data Continuation Number
The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 10 of 23 Appendix B-72 8660F10 April 2023

Crawford & Associates, Inc.
4701 Freeport Blvd
Sacramento, CA 95822
Project:

Project Number:

Project Manager:

Sludge
19-503.1 WWTP Sludge Pod
Armando Castro
Reported: 11/03/2022 15:30
BCL Sample ID: 2225679-01 Client Sample Name:

Constituent Result Units Method Bias Quals
MB Lab
Total Concentrations (TTLC)
DCN
LEAN CLAY TRANSITION FROM SEWAGE SLUDGE, 9/30/2022 12:00:00PM, Shelby Tube

PQL MDL
Antimony 7.8 mg/kg 50 3.3 EPA-6010B ND J,A10 1
Arsenic 5.7 mg/kg 10 4.0 EPA-6010B ND J,A10 1
Barium 410 mg/kg 5.0 1.8 EPA-6010B ND A10 1
Beryllium ND mg/kg 5.0 0.47 EPA-6010B ND A10 1
Cadmium 0.88 mg/kg 5.0 0.52 EPA-6010B ND J,A10 1
Chromium 47 mg/kg 5.0 0.50 EPA-6010B ND A10 1
Cobalt 5.2 mg/kg 25 0.98 EPA-6010B ND J,A10 1
Copper 280 mg/kg 10 0.50 EPA-6010B 2.5 A10 1
Lead 26 mg/kg 25 4.1 EPA-6010B ND A10 1
Mercury 1.1 mg/kg 0.16 0.016 EPA-7471A 0.061 S05 2
Molybdenum 0.80 mg/kg 25 0.50 EPA-6010B ND J,A10 1
Nickel 33 mg/kg 5.0 1.5 EPA-6010B 1.8 A10 1
Selenium ND mg/kg 10 9.8 EPA-6010B ND A10 1
Silver 13 mg/kg 5.0 0.67 EPA-6010B ND A10 1
Thallium ND mg/kg 50 6.4 EPA-6010B ND A10 1
Vanadium 29 mg/kg 5.0 1.1 EPA-6010B ND A10 1
Zinc 1300 mg/kg 25 0.87 EPA-6010B 5.0 A10 1
QC
Date/Time Analyst Instrument Dilution Batch ID
Run
DCN Method Prep Date Prep Method
1 EPA-6010B 11/01/22 19:25 11/02/22 11:33 JCC PE-OP3 9.259 B152776 EPA 3050B 2 EPA-7471A 11/03/22 08:05 11/03/22 10:16 TMT CETAC3 1.008 B152995 EPA 7471A DCN = Data Continuation Number
The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 11 of 23 Appendix B-73 8660F10 April 2023

Crawford & Associates, Inc.
4701 Freeport Blvd
Sacramento, CA 95822
Project:

Project Number:

Project Manager:

Sludge
19-503.1 WWTP Sludge Pod
Armando Castro
Reported: 11/03/2022 15:30
Quality Control Report - Method Blank Analysis
Constituent QC Sample ID MB Result Units Lab Quals
Volatile Organic Analysis (EPA Method 8260B)

PQL MDL
QC Batch ID: B152390
Benzene B152390-BLK1 ND mg/kg 0.0050 0.00067
Bromobenzene B152390-BLK1 ND mg/kg 0.0050 0.00087
Bromochloromethane B152390-BLK1 ND mg/kg 0.0050 0.00081 Bromodichloromethane B152390-BLK1 ND mg/kg 0.0050 0.00078 Bromoform B152390-BLK1 ND mg/kg 0.0050 0.00070
Bromomethane B152390-BLK1 ND mg/kg 0.0050 0.0017
n-Butylbenzene B152390-BLK1 ND mg/kg 0.0050 0.00076
sec-Butylbenzene B152390-BLK1 ND mg/kg 0.0050 0.00071
tert-Butylbenzene B152390-BLK1 ND mg/kg 0.0050 0.00085
Carbon tetrachloride B152390-BLK1 ND mg/kg 0.0050 0.00078 Chlorobenzene B152390-BLK1 ND mg/kg 0.0050 0.00077
Chloroethane B152390-BLK1 ND mg/kg 0.0050 0.0011
Chloroform B152390-BLK1 ND mg/kg 0.0050 0.00090
Chloromethane B152390-BLK1 ND mg/kg 0.0050 0.0011
2-Chlorotoluene B152390-BLK1 ND mg/kg 0.0050 0.00087
4-Chlorotoluene B152390-BLK1 ND mg/kg 0.0050 0.00070
Dibromochloromethane B152390-BLK1 ND mg/kg 0.0050 0.00080 1,2-Dibromo-3-chloropropane B152390-BLK1 ND mg/kg 0.0050 0.00096 1,2-Dibromoethane B152390-BLK1 ND mg/kg 0.0050 0.00082
Dibromomethane B152390-BLK1 ND mg/kg 0.0050 0.0014
1,2-Dichlorobenzene B152390-BLK1 ND mg/kg 0.0050 0.00079 1,3-Dichlorobenzene B152390-BLK1 ND mg/kg 0.0050 0.00073 1,4-Dichlorobenzene B152390-BLK1 ND mg/kg 0.0050 0.00073 Dichlorodifluoromethane B152390-BLK1 ND mg/kg 0.0050 0.00079 1,1-Dichloroethane B152390-BLK1 ND mg/kg 0.0050 0.00064 1,2-Dichloroethane B152390-BLK1 ND mg/kg 0.0050 0.00073 1,1-Dichloroethene B152390-BLK1 ND mg/kg 0.0050 0.0011
cis-1,2-Dichloroethene B152390-BLK1 ND mg/kg 0.0050 0.00054 trans-1,2-Dichloroethene B152390-BLK1 ND mg/kg 0.0050 0.0037 1,2-Dichloropropane B152390-BLK1 ND mg/kg 0.0050 0.00080 1,3-Dichloropropane B152390-BLK1 ND mg/kg 0.0050 0.00067 2,2-Dichloropropane B152390-BLK1 ND mg/kg 0.0050 0.00067 1,1-Dichloropropene B152390-BLK1 ND mg/kg 0.0050 0.00067 cis-1,3-Dichloropropene B152390-BLK1 ND mg/kg 0.0050 0.00058 The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 12 of 23 Appendix B-74 8660F10 April 2023

Crawford & Associates, Inc.
4701 Freeport Blvd
Sacramento, CA 95822
Project:

Project Number:

Project Manager:

Sludge
19-503.1 WWTP Sludge Pod
Armando Castro
Reported: 11/03/2022 15:30
Quality Control Report - Method Blank Analysis
Constituent QC Sample ID MB Result Units Lab Quals
Volatile Organic Analysis (EPA Method 8260B)

PQL MDL
QC Batch ID: B152390
trans-1,3-Dichloropropene B152390-BLK1 ND mg/kg 0.0050 0.00066 Ethylbenzene B152390-BLK1 ND mg/kg 0.0050 0.00069
Hexachlorobutadiene B152390-BLK1 ND mg/kg 0.0050 0.00067 Isopropylbenzene B152390-BLK1 ND mg/kg 0.0050 0.00080
p-Isopropyltoluene B152390-BLK1 ND mg/kg 0.0050 0.00059 Methylene chloride B152390-BLK1 ND mg/kg 0.010 0.0011
Methyl t-butyl ether B152390-BLK1 ND mg/kg 0.0050 0.00056 Naphthalene B152390-BLK1 ND mg/kg 0.0050 0.00099
n-Propylbenzene B152390-BLK1 ND mg/kg 0.0050 0.00071
Styrene B152390-BLK1 ND mg/kg 0.0050 0.00062
1,1,1,2-Tetrachloroethane B152390-BLK1 ND mg/kg 0.0050 0.00095 1,1,2,2-Tetrachloroethane B152390-BLK1 ND mg/kg 0.0050 0.00084 Tetrachloroethene B152390-BLK1 ND mg/kg 0.0050 0.00097
Toluene B152390-BLK1 ND mg/kg 0.0050 0.00069
1,2,3-Trichlorobenzene B152390-BLK1 ND mg/kg 0.0050 0.0015 1,2,4-Trichlorobenzene B152390-BLK1 ND mg/kg 0.0050 0.0014 1,1,1-Trichloroethane B152390-BLK1 ND mg/kg 0.0050 0.00067 1,1,2-Trichloroethane B152390-BLK1 ND mg/kg 0.0050 0.00094 Trichloroethene B152390-BLK1 ND mg/kg 0.0050 0.00074
Trichlorofluoromethane B152390-BLK1 ND mg/kg 0.0050 0.0015 1,2,3-Trichloropropane B152390-BLK1 ND mg/kg 0.0050 0.0019 1,1,2-Trichloro-1,2,2-trifluoroethane B152390-BLK1 ND mg/kg 0.0050 0.0010 1,2,4-Trimethylbenzene B152390-BLK1 ND mg/kg 0.0050 0.00080 1,3,5-Trimethylbenzene B152390-BLK1 ND mg/kg 0.0050 0.00066 Vinyl chloride B152390-BLK1 ND mg/kg 0.0050 0.00059
Total Xylenes B152390-BLK1 ND mg/kg 0.010 0.0025
p- & m-Xylenes B152390-BLK1 ND mg/kg 0.0050 0.0015
o-Xylene B152390-BLK1 ND mg/kg 0.0050 0.00093
1,2-Dichloroethane-d4 (Surrogate) B152390-BLK1 98.4 % 70 - 121 (LCL - UCL) Toluene-d8 (Surrogate) B152390-BLK1 99.6 % 81 - 117 (LCL - UCL) 4-Bromofluorobenzene (Surrogate) B152390-BLK1 99.2 % 74 - 121 (LCL - UCL) The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 13 of 23 Appendix B-75 8660F10 April 2023

Crawford & Associates, Inc.
4701 Freeport Blvd
Sacramento, CA 95822
Project:

Project Number:

Project Manager:

Sludge
19-503.1 WWTP Sludge Pod
Armando Castro
Reported: 11/03/2022 15:30
Quality Control Report - Laboratory Control Sample
Constituent
Control Limits
Spike Percent Percent
QC Sample ID Type Result Level Units Recovery RPD Recovery RPD Quals Volatile Organic Analysis (EPA Method 8260B)
Lab
QC Batch ID: B152390
Benzene B152390-BS1 LCS 0.13708 0.12500 mg/kg 110 70 - 130 Bromodichloromethane B152390-BS1 LCS 0.14381 0.12500 mg/kg 115 70 - 130 Chlorobenzene B152390-BS1 LCS 0.13978 0.12500 mg/kg 112 70 - 130 Chloroethane B152390-BS1 LCS 0.14427 0.12500 mg/kg 115 70 - 130 1,4-Dichlorobenzene B152390-BS1 LCS 0.14223 0.12500 mg/kg 114 70 - 130 1,1-Dichloroethane B152390-BS1 LCS 0.13597 0.12500 mg/kg 109 70 - 130 1,1-Dichloroethene B152390-BS1 LCS 0.14655 0.12500 mg/kg 117 70 - 130 Toluene B152390-BS1 LCS 0.14644 0.12500 mg/kg 117 70 - 130 Trichloroethene B152390-BS1 LCS 0.15456 0.12500 mg/kg 124 70 - 130 1,2-Dichloroethane-d4 (Surrogate) B152390-BS1 LCS 0.045020 0.050000 mg/kg 90.0 70 - 121 Toluene-d8 (Surrogate) B152390-BS1 LCS 0.048760 0.050000 mg/kg 97.5 81 - 117 4-Bromofluorobenzene (Surrogate) B152390-BS1 LCS 0.049490 0.050000 mg/kg 99.0 74 - 121 The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 14 of 23 Appendix B-76 8660F10 April 2023

Crawford & Associates, Inc.
4701 Freeport Blvd
Sacramento, CA 95822
Project:

Project Number:

Project Manager:

Sludge
19-503.1 WWTP Sludge Pod
Armando Castro
Reported: 11/03/2022 15:30
Quality Control Report - Precision & Accuracy
Constituent Type Sample ID Result Result Added Units RPD Recovery RPD Recovery Quals Source Spike Percent Percent
Control Limits
Volatile Organic Analysis (EPA Method 8260B)
Source Lab
QC Batch ID: B152390 Used client sample: N
Benzene MS 2224765-22 ND 0.14902 0.12500 mg/kg 119 70 - 130 MSD 2224765-22 ND 0.14447 0.12500 mg/kg 3.1 116 20 70 - 130 Bromodichloromethane MS 2224765-22 ND 0.15677 0.12500 mg/kg 125 70 - 130 MSD 2224765-22 ND 0.14188 0.12500 mg/kg 10.0 114 20 70 - 130 Chlorobenzene MS 2224765-22 ND 0.15099 0.12500 mg/kg 121 70 - 130 MSD 2224765-22 ND 0.14167 0.12500 mg/kg 6.4 113 20 70 - 130 Chloroethane MS 2224765-22 ND 0.14009 0.12500 mg/kg 112 70 - 130 MSD 2224765-22 ND 0.13792 0.12500 mg/kg 1.6 110 20 70 - 130 1,4-Dichlorobenzene MS 2224765-22 ND 0.15418 0.12500 mg/kg 123 70 - 130 MSD 2224765-22 ND 0.14521 0.12500 mg/kg 6.0 116 20 70 - 130 1,1-Dichloroethane MS 2224765-22 ND 0.14913 0.12500 mg/kg 119 70 - 130 MSD 2224765-22 ND 0.14578 0.12500 mg/kg 2.3 117 20 70 - 130 1,1-Dichloroethene MS 2224765-22 ND 0.15412 0.12500 mg/kg 123 70 - 130 MSD 2224765-22 ND 0.14789 0.12500 mg/kg 4.1 118 20 70 - 130 Toluene MS 2224765-22 ND 0.16058 0.12500 mg/kg 128 70 - 130 MSD 2224765-22 ND 0.14508 0.12500 mg/kg 10.1 116 20 70 - 130 Trichloroethene MS 2224765-22 ND 0.16861 0.12500 mg/kg 135 70 - 130 Q03 MSD 2224765-22 ND 0.14995 0.12500 mg/kg 11.7 120 20 70 - 130 1,2-Dichloroethane-d4 (Surrogate) MS 2224765-22 ND 0.045010 0.050000 mg/kg 90.0 70 - 121 MSD 2224765-22 ND 0.045300 0.050000 mg/kg 0.6 90.6 70 - 121 Toluene-d8 (Surrogate) MS 2224765-22 ND 0.049360 0.050000 mg/kg 98.7 81 - 117 MSD 2224765-22 ND 0.048210 0.050000 mg/kg 2.4 96.4 81 - 117 4-Bromofluorobenzene (Surrogate) MS 2224765-22 ND 0.051680 0.050000 mg/kg 103 74 - 121 MSD 2224765-22 ND 0.051340 0.050000 mg/kg 0.7 103 74 - 121 The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 15 of 23 Appendix B-77 8660F10 April 2023

Crawford & Associates, Inc.
4701 Freeport Blvd
Sacramento, CA 95822
Project:

Project Number:

Project Manager:

Sludge
19-503.1 WWTP Sludge Pod
Armando Castro
Reported: 11/03/2022 15:30
Quality Control Report - Method Blank Analysis
Constituent QC Sample ID MB Result Units Lab Quals
Purgeable Aromatics and Total Petroleum Hydrocarbons

PQL MDL
QC Batch ID: B152311
Gasoline Range Organics (C4 - C12) B152311-BLK1 ND mg/kg 1.0 0.20 a,a,a-Trifluorotoluene (FID Surrogate) B152311-BLK1 80.0 % 70 - 130 (LCL - UCL) The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 16 of 23 Appendix B-78 8660F10 April 2023

Crawford & Associates, Inc.
4701 Freeport Blvd
Sacramento, CA 95822
Project:

Project Number:

Project Manager:

Sludge
19-503.1 WWTP Sludge Pod
Armando Castro
Reported: 11/03/2022 15:30
Quality Control Report - Laboratory Control Sample
Constituent
Control Limits
Spike Percent Percent
QC Sample ID Type Result Level Units Recovery RPD Recovery RPD Quals Purgeable Aromatics and Total Petroleum Hydrocarbons
Lab
QC Batch ID: B152311
Gasoline Range Organics (C4 - C12) B152311-BS1 LCS 5.1770 5.0000 mg/kg 104 85 - 115 a,a,a-Trifluorotoluene (FID Surrogate) B152311-BS1 LCS 0.038000 0.040000 mg/kg 95.0 70 - 130 The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 17 of 23 Appendix B-79 8660F10 April 2023

Crawford & Associates, Inc.
4701 Freeport Blvd
Sacramento, CA 95822
Project:

Project Number:

Project Manager:

Sludge
19-503.1 WWTP Sludge Pod
Armando Castro
Reported: 11/03/2022 15:30
Quality Control Report - Precision & Accuracy
Constituent Type Sample ID Result Result Added Units RPD Recovery RPD Recovery Quals Source Spike Percent Percent
Control Limits
Purgeable Aromatics and Total Petroleum Hydrocarbons
Source Lab
QC Batch ID: B152311 Used client sample: N
Gasoline Range Organics (C4 - C12) MS 2224765-02 ND 5.1980 5.0000 mg/kg 104 70 - 130 MSD 2224765-02 ND 5.1910 5.0000 mg/kg 0.1 104 20 70 - 130 a,a,a-Trifluorotoluene (FID Surrogate) MS 2224765-02 ND 0.038000 0.040000 mg/kg 95.0 70 - 130 MSD 2224765-02 ND 0.038000 0.040000 mg/kg 0 95.0 70 - 130 The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 18 of 23 Appendix B-80 8660F10 April 2023

Crawford & Associates, Inc.
4701 Freeport Blvd
Sacramento, CA 95822
Project:

Project Number:

Project Manager:

Sludge
19-503.1 WWTP Sludge Pod
Armando Castro
Reported: 11/03/2022 15:30
Quality Control Report - Method Blank Analysis
Constituent QC Sample ID MB Result Units Lab Quals
Total Concentrations (TTLC)

PQL MDL
QC Batch ID: B152776
Antimony B152776-BLK1 ND mg/kg 5.0 0.33
Arsenic B152776-BLK1 ND mg/kg 1.0 0.40
Barium B152776-BLK1 ND mg/kg 0.50 0.18
Beryllium B152776-BLK1 ND mg/kg 0.50 0.047
Cadmium B152776-BLK1 ND mg/kg 0.50 0.052
Chromium B152776-BLK1 0.052190 mg/kg 0.50 0.050 J
Cobalt B152776-BLK1 ND mg/kg 2.5 0.098
Copper B152776-BLK1 0.26533 mg/kg 1.0 0.050 J
Lead B152776-BLK1 ND mg/kg 2.5 0.41
Molybdenum B152776-BLK1 ND mg/kg 2.5 0.050
Nickel B152776-BLK1 0.19101 mg/kg 0.50 0.15 J
Selenium B152776-BLK1 ND mg/kg 1.0 0.98
Silver B152776-BLK1 ND mg/kg 0.50 0.067
Thallium B152776-BLK1 ND mg/kg 5.0 0.64
Vanadium B152776-BLK1 ND mg/kg 0.50 0.11
Zinc B152776-BLK1 0.54072 mg/kg 2.5 0.087 J
QC Batch ID: B152995
Mercury B152995-BLK1 0.060160 mg/kg 0.16 0.016 J
The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 19 of 23 Appendix B-81 8660F10 April 2023

Crawford & Associates, Inc.
4701 Freeport Blvd
Sacramento, CA 95822
Project:

Project Number:

Project Manager:

Sludge
19-503.1 WWTP Sludge Pod
Armando Castro
Reported: 11/03/2022 15:30
Quality Control Report - Laboratory Control Sample
Constituent
Control Limits
Spike Percent Percent
QC Sample ID Type Result Level Units Recovery RPD Recovery RPD Quals Total Concentrations (TTLC)
Lab
QC Batch ID: B152776
Antimony B152776-BS1 LCS 105.08 100.00 mg/kg 105 75 - 125 Arsenic B152776-BS1 LCS 19.457 20.000 mg/kg 97.3 75 - 125 Barium B152776-BS1 LCS 106.13 100.00 mg/kg 106 75 - 125 Beryllium B152776-BS1 LCS 10.057 10.000 mg/kg 101 75 - 125 Cadmium B152776-BS1 LCS 10.630 10.000 mg/kg 106 75 - 125 Chromium B152776-BS1 LCS 108.63 100.00 mg/kg 109 75 - 125 Cobalt B152776-BS1 LCS 109.49 100.00 mg/kg 109 75 - 125 Copper B152776-BS1 LCS 103.60 100.00 mg/kg 104 75 - 125 Lead B152776-BS1 LCS 114.12 100.00 mg/kg 114 75 - 125
Molybdenum B152776-BS1 LCS 107.53 100.00 mg/kg 108 75 - 125 Nickel B152776-BS1 LCS 113.63 100.00 mg/kg 114 75 - 125 Selenium B152776-BS1 LCS 18.784 20.000 mg/kg 93.9 75 - 125 Silver B152776-BS1 LCS 10.308 10.000 mg/kg 103 75 - 125 Thallium B152776-BS1 LCS 121.11 100.00 mg/kg 121 75 - 125 Vanadium B152776-BS1 LCS 103.96 100.00 mg/kg 104 75 - 125 Zinc B152776-BS1 LCS 106.54 100.00 mg/kg 107 75 - 125
QC Batch ID: B152995
Mercury B152995-BS1 LCS 0.83680 0.80000 mg/kg 105 80 - 120 The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 20 of 23 Appendix B-82 8660F10 April 2023

Crawford & Associates, Inc.
4701 Freeport Blvd
Sacramento, CA 95822
Project:

Project Number:

Project Manager:

Sludge
19-503.1 WWTP Sludge Pod
Armando Castro
Reported: 11/03/2022 15:30
Quality Control Report - Precision & Accuracy
Constituent Type Sample ID Result Result Added Units RPD Recovery RPD Recovery Quals Source Spike Percent Percent
Control Limits
Total Concentrations (TTLC)
Source Lab
QC Batch ID: B152776 Used client sample: N
Antimony DUP 2226003-01 3.1699 2.8378 mg/kg 11.1 20 J
MS 2226003-01 3.1699 27.446 100.00 mg/kg 24.3 16 - 119
MSD 2226003-01 3.1699 28.774 100.00 mg/kg 4.7 25.6 20 16 - 119 Arsenic DUP 2226003-01 49.659 52.349 mg/kg 5.3 20
MS 2226003-01 49.659 66.009 20.000 mg/kg 81.7 75 - 125
MSD 2226003-01 49.659 66.334 20.000 mg/kg 0.5 83.4 20 75 - 125 Barium DUP 2226003-01 81.456 84.850 mg/kg 4.1 20
MS 2226003-01 81.456 140.93 100.00 mg/kg 59.5 75 - 125 Q03 MSD 2226003-01 81.456 144.17 100.00 mg/kg 2.3 62.7 20 75 - 125 Q03 Beryllium DUP 2226003-01 0.34819 0.35475 mg/kg 1.9 20 J MS 2226003-01 0.34819 8.6702 10.000 mg/kg 83.2 75 - 125 MSD 2226003-01 0.34819 8.8178 10.000 mg/kg 1.7 84.7 20 75 - 125 Cadmium DUP 2226003-01 0.75360 0.74293 mg/kg 1.4 20
MS 2226003-01 0.75360 9.9102 10.000 mg/kg 91.6 75 - 125 MSD 2226003-01 0.75360 9.9587 10.000 mg/kg 0.5 92.1 20 75 - 125 Chromium DUP 2226003-01 9.5226 9.9237 mg/kg 4.1 20
MS 2226003-01 9.5226 95.956 100.00 mg/kg 86.4 75 - 125
MSD 2226003-01 9.5226 96.117 100.00 mg/kg 0.2 86.6 20 75 - 125 Cobalt DUP 2226003-01 4.1017 4.3320 mg/kg 5.5 20
MS 2226003-01 4.1017 94.204 100.00 mg/kg 90.1 75 - 125
MSD 2226003-01 4.1017 89.162 100.00 mg/kg 5.5 85.1 20 75 - 125 Copper DUP 2226003-01 9.6953 9.5397 mg/kg 1.6 20
MS 2226003-01 9.6953 102.40 100.00 mg/kg 92.7 75 - 125
MSD 2226003-01 9.6953 103.70 100.00 mg/kg 1.3 94.0 20 75 - 125 Lead DUP 2226003-01 3.1428 3.3825 mg/kg 7.3 20
MS 2226003-01 3.1428 90.280 100.00 mg/kg 87.1 75 - 125
MSD 2226003-01 3.1428 90.606 100.00 mg/kg 0.4 87.5 20 75 - 125 Molybdenum DUP 2226003-01 ND ND mg/kg 20
MS 2226003-01 ND 84.174 100.00 mg/kg 84.2 75 - 125
MSD 2226003-01 ND 85.211 100.00 mg/kg 1.2 85.2 20 75 - 125 Nickel DUP 2226003-01 7.0980 7.2357 mg/kg 1.9 20
MS 2226003-01 7.0980 93.441 100.00 mg/kg 86.3 75 - 125
MSD 2226003-01 7.0980 93.723 100.00 mg/kg 0.3 86.6 20 75 - 125 Selenium DUP 2226003-01 ND ND mg/kg 20
MS 2226003-01 ND 17.017 20.000 mg/kg 85.1 75 - 125
MSD 2226003-01 ND 15.841 20.000 mg/kg 7.2 79.2 20 75 - 125 Silver DUP 2226003-01 ND ND mg/kg 20
MS 2226003-01 ND 8.8415 10.000 mg/kg 88.4 75 - 125
MSD 2226003-01 ND 8.9242 10.000 mg/kg 0.9 89.2 20 75 - 125 The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 21 of 23 Appendix B-83 8660F10 April 2023

Crawford & Associates, Inc.
4701 Freeport Blvd
Sacramento, CA 95822
Project:

Project Number:

Project Manager:

Sludge
19-503.1 WWTP Sludge Pod
Armando Castro
Reported: 11/03/2022 15:30
Quality Control Report - Precision & Accuracy
Constituent Type Sample ID Result Result Added Units RPD Recovery RPD Recovery Quals Source Spike Percent Percent
Control Limits
Total Concentrations (TTLC)
Source Lab
QC Batch ID: B152776 Used client sample: N
Thallium DUP 2226003-01 ND ND mg/kg 20
MS 2226003-01 ND 87.788 100.00 mg/kg 87.8 75 - 125
MSD 2226003-01 ND 88.225 100.00 mg/kg 0.5 88.2 20 75 - 125 Vanadium DUP 2226003-01 20.042 20.682 mg/kg 3.1 20
MS 2226003-01 20.042 109.35 100.00 mg/kg 89.3 75 - 125
MSD 2226003-01 20.042 109.54 100.00 mg/kg 0.2 89.5 20 75 - 125 Zinc DUP 2226003-01 28.891 29.104 mg/kg 0.7 20
MS 2226003-01 28.891 118.51 100.00 mg/kg 89.6 75 - 125
MSD 2226003-01 28.891 118.61 100.00 mg/kg 0.1 89.7 20 75 - 125 QC Batch ID: B152995 Used client sample: N
Mercury DUP 2225805-01 0.46825 0.46984 mg/kg 0.3 20
MS 2225805-01 0.46825 1.3667 0.79365 mg/kg 113 80 - 120 MSD 2225805-01 0.46825 1.3603 0.79365 mg/kg 0.5 112 20 80 - 120 The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 22 of 23 Appendix B-84 8660F10 April 2023

Crawford & Associates, Inc.
4701 Freeport Blvd
Sacramento, CA 95822
Project:

Project Number:

Project Manager:

Sludge
19-503.1 WWTP Sludge Pod
Armando Castro
Reported: 11/03/2022 15:30
Notes And Definitions
J Estimated Value (CLP Flag)
MDL Method Detection Limit
ND Analyte Not Detected
PQL Practical Quantitation Limit
A10 Detection and quantitation limits were raised due to matrix interference.

A20 Surrogate is low due to matrix interference. Interference verified through second extraction/analysis.

A26 Sample received past holding time.

Q03 Matrix spike recovery(s) was(were) not within the control limits.

S05 The sample holding time was exceeded.

S09 The surrogate recovery for this compound was not within the control limits.

The results in this report apply to the samples analyzed in accordance with the chain of custody document . This analytical report must be reproduced in its entirety.

All results listed in this report are for the exclusive use of the submitting party. Pace Analytical assumes no responsibility for report alteration, separation, detachment or third party interpretation. 4100 Atlas Court Bakersfield, CA 93308 (661) 327-4911 FAX (661) 327-1918 www.pacelabs.com Report ID: 1001363273 Page 23 of 23 Appendix B-85 8660F10 April 2023

Appendix B-86 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT (Revision 2) Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California February 3, 2023

APPENDIX IV
Site-Specific Ground Motion Hazard Analysis
Appendix B-87 8660F10 April 2023

Appendix B-88 8660F10 April 2023

1 Corporate Office: 1100 Corporate Drive, Suite 230 | Sacramento, CA 95831 | (916) 455-4225 Modesto: 1165 Scenic Drive, Suite A | Modesto, CA 95350 | (209) 312-7668 Pleasanton: 6200 Stoneridge Mall Road, Suite 330 | Pleasanton, CA 94588 | (925) 401-3515 Rocklin: 4220 Rocklin Road, Suite 1 | Rocklin, CA 95677 | (916) 455-4225 Ukiah: 100 North Pine Street | Ukiah, CA 95482| (707) 240-4400

APPENDIX IV

DRAFT SITE-SPECIFIC GROUND MOTION HAZARD MEMORANDUM
CITY OF UKIAH RECYCLED WATER PIPELINE – PHASE 4 DESIGN PROJECT

SLUDGE BASIN

UKIAH, CALIFORNIA
1 INTRODUCTION
Crawford completed two borings in 2022 at the City of Ukiah Wastewater Treatment Plant to supplement the two Crawford borings completed in 2017 and a site-specific ground motion hazard analysis for compliancy with ASCE 7-16 (with Supplement 1) and 2019 CBC. 2 SITE SPECIFIC ANALYSIS
The following sections describe the site-specific ground motion analysis.

2.1 INITIAL SEISMIC HAZARD ANALYSIS

2.1.1 SEISMIC DESIGN CRITERIA
Seismic design criteria are included in Section 11 of ASCE 7-16 (Sections referenced hereafter refer to ASCE 7-16), including mapped acceleration parameters. These mapped parameters are available online through the SEAOC/OSHPD1 Seismic Design website, which interpolates values from the ASCE 7-16 maps using the site location.

2.1.2 SITE CLASS AND RISK CATEGORY
The site was classified as Site Class D according to Section 20.3.13. Boring A-22-001 and B-1 (2017) shows discontinuous potentially liquefiable layers from 28 to 33 feet below ground surface (bgs); based on the discontinuous layers of loose and we consider the liquefaction risk to be low and classify the site as Site Class D.

The shear wave velocity of 210 meters per second (m/s) in the upper 30 meters or 100 feet (VS30) used for the site was developed from 2017 boring data. Crawford used correlations with SPT blow count N-values corrected for hammer efficiency to determine VS values in soil per Caltrans correlations2
. The Risk Category for the structure was assumed to be III.

2.1.3 MAPPED ACCELERATION PARAMETERS
Crawford accessed the SEAOC/OSHPD Seismic Design Map website considering the site location latitude 37.1117°N and longitude 123.1900°W, Site Class D, and Risk Category III to determine the Mapped Maximum Considered Earthquake (MCE) Spectral Response Short Period (SS), Mapped MCE Spectral Response at 1 second period (S1), Long Period (TL), and mapped risked coefficients (CRS and CR1). The SS, S1, TL, CRS, and CR1 are coordinate specific and are taken from ASCE 7-16 figures independently of site class. The mapped acceleration parameters are based on an MCE which is roughly equivalent to an earthquake with a 2% chance of 1 https://seismicmaps.org
2 Caltrans "Methodology for Developing Design Response Spectrum for Use in Seismic Design Recommendations", Appendix A, pgs 15-18, November 2012.

Appendix B-89 8660F10 April 2023

Appendix IV
SITE-SPECIFIC HARZARD MEMORANDUM Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California November 9, 2022
2 exceedance in 50 years (2,475-year return period). Table 1 summarizes the mapped acceleration parameters.

Table 1: Mapped Acceleration Parameters

2.2 HORIZONTAL GROUND MOTION HAZARD ANALYSIS
A ground motion hazard analysis accounts for the regional tectonic setting, geology, and seismicity of a specific site as well as the expected recurrence of the maximum magnitudes of the earthquakes on known faults and source zones, considering ground motion attenuation and near source effects. The methodology included in ASCE 7-16 was used to determine the site-specific ground motions of the project site, generally consisting of the following steps:

Determine the probabilistic MCE ground motions
Determine the deterministic MCE ground motions
Adjust MCE ground motions to maximum horizontal response Adjust probabilistic MCE ground motions to risk-targeted maximum considered earthquake ground motions (MCER)
Compare and scale the site-specific deterministic MCE ground motion with minimum spectral responses to ASCE 7-16 Supplement 1 Section 21.2.2 Calculate design spectral response ground motion (2/3 of MCER) Compare the Section 21.2 design spectral response ground motion to the Section 11.4.6 design spectral response ground motion (cannot be lower than 80% Section 11.4.6 design spectral response ground motion)
Determine the design spectral response spectrum and design acceleration parameters Calculate peak ground acceleration (PGAM)

2.2.1 GROUND MOTION HAZARD ANALYSIS
Crawford performed a seismic hazard analyses and site response analyses using EZ-FRISK software Version 8.07. Crawford used the following next generation attenuation relationships (NGA) all equally weighted for the nearby strike-slip and reverse faults:

Boore-et al (2014)
Campbell and Bozorgnia (2014)
Chiou and Youngs (2014)
Mapped Acceleration Parameter Value Source
Mapped MCER Spectral Response Short Period (SS) 1.88 Figure 21-1 Mapped MCER Spectral Response at 1 Second Period (S1) 0.719 Figure 21-2 Long Period (TL) 8 Figure 21-14
Mapped Risk Coefficient at Short Period (CRS) 0.887 Figure 22-17 Mapped Risk Coefficient at 1 Second Period (CR1) 0.881 Figure 22-18 Appendix B-90 8660F10 April 2023

Appendix IV
SITE-SPECIFIC HARZARD MEMORANDUM Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California November 9, 2022
3 Table 2: Summary of Seismic Sources
Attenuation
Relationship
Type
Source Distance
(km)
Maximum
Magnitude Mechanism Dip Angle(degree)
Dips
Direction
Site
Lies
NGA
California
Gridded 0 7 SS|R 90 -- Above
Great Valley
2 11.16 6.501 Reverse 15 W E
Great Valley
3, Mysterious
Ridge

11.25 7.1 Reverse 20 SW NE
Great Valley
1 22.01 6.8 Reverse 15 W S
Hunting
CreekBerryessa

33.58 7.1 Strike Slip 90 -- NE
Bartlett
Springs 33.76 7.3 Strike Slip 90 -- NE
Great Valley
4a, Trout
Creek

48.67 6.6 Reverse 20 SW N
Collayomi 55.80 6.7 Strike Slip 90 -- NE
Shear 1
Gridded 61.34 7.6 Strike Slip 90 -- SW
Great Valley
4b, Gordon
Valley

66.59 6.8 Reverse 20 W N
MaacamaGerberville 71.53 7.4 Strike Slip 90 -- NE
HaywardRodgers
Creek

78.97 7.334 Strike Slip 90 -- NE
West Napa 79.32 6.7 Strike Slip 90 -- N
Great Valley
Connected 81.12 6.8 Strike Slip 90 -- N
Great Valley
5, Pittsburg
Kirby Hills

94.36 6.7 Strike Slip 90 -- N
Northern San
Andreas 110.96 8.05 Strike Slip 90 -- NE
Shear 3
Gridded 121.95 7.6 Strike Slip 90 -- SW
Shear 2
Gridded 124.76 7.6 Strike Slip 90 -- SW
Point Reyes 130.47 6.9 Reverse 50 NE NE
Appendix B-91 8660F10 April 2023

Appendix IV
SITE-SPECIFIC HARZARD MEMORANDUM Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California November 9, 2022
4 The following parameters were common to all analyses for each of the attenuation relationships:

The VS30 of the site of 210 m/s
Depth to soil with a VS of 1,000 m/s was calculated to be 336 meters based on the methodology proposed by Chiou and Youngs (2008)
Depth to soil with a VS of 2,500 m/s was calculated to be 1.72 kilometers based on the methodology proposed by Campbell and Bozorgnia (2008)

2.2.2 PROBABILISTIC MCER GROUND MOTION
Seismic sources within 200 kilometers were used to determine the site-specific ground motions.

The NGA analyses considered the following faults in Table 2.

EZ-FRISK software was used to determine geometric mean spectral response acceleration predicted using NGA from a 5% damped response spectrum with a 2% in 50-year exceedance Attenuation
Relationship
Type
Source Distance
(km)
Maximum
Magnitude Mechanism Dip Angle(degree)
Dips
Direction
Site
Lies
Mount Diablo
Thrust 131.91 6.7 Reverse 38 NE N
Greenville
Connected 139.94 7 Strike Slip 90 -- N
Greenville
Connected U 139.94 7 Strike Slip 90 -- N
Shear 4
Gridded 140.52 7.6 Strike Slip 90 -- W
Battle Creek 141.30 6.7 Normal 75 S S
Calaveras 144.71 7.025 Strike Slip 90 -- N
Mendocino
Gridded,
Reverse
150.45 7.3 Reverse 90 -- SE
Mendocino
Gridded,
Strike Slip
150.45 7.3 Reverse 90 -- SE
San Gregorio
Connected 153.85 7.5 Strike Slip 90 -- N
Great Valley
7 163.82 6.9 Reverse 15 SW N
Hat CreekMcArthurMayfield
178.61 7.2 Normal 60 W S
West Tahoe 179.06 7.1 Normal 50 E W
North Tahoe 184.55 6.7 Normal 50 E W
Monte VistaShannon 186.13 6.501 Reverse 45 SW N
Honey Lake 194.33 7 Strike Slip 90 -- SW
Appendix B-92 8660F10 April 2023

Appendix IV
SITE-SPECIFIC HARZARD MEMORANDUM Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California November 9, 2022
5 probability. Crawford scaled the NGA geometric mean spectral response to the maximum rotated spectral using the scale factors in Section 21.1.

A. RISK COEFFICIENTS
Method 1 of Section 21.2 was used to determine the probabilistic MCER ground motion Mapped risk coefficients (CRS and CR1) were used to adjust the response accelerations to a 1% chance of collapse in 50 years per Section 21.2.1.1. The risk coefficients are summarized in Table 1, along with the source figure from ASCE 7-16.

CRS was applied to accelerations at spectral periods less than or equal to 0.2 seconds. CR1 was applied accelerations at spectral periods greater than or equal to 1 second. For spectral periods between 0.2 and 1 seconds, the CR value was linearly interpolated.

B. PROBABILISTIC MCER GROUND MOTION
Figure IV-1 shows the geometric mean spectral response for the 2% in 50-year event developed using EZ-FRISK for each of the attenuation relationships described above. Also shown is the risk-adjusted response spectrum adjusting the response to a 1% in 50-year probability of collapse, which is equivalent to the site-specific probabilistic ground motion MCER.

2.2.3 DETERMINISTIC MCER GROUND MOTION
The deterministic spectral response acceleration is defined as the 84th-percentile 5% damped spectral response in the direction of maximum horizontal response for the characteristic earthquake on all known active faults within the region. EZ-FRISK was used to calculate the deterministic ground motion per Section 21.2.2. The NGA controlled deterministic spectral response was taken as the largest amplitude of ground motion considering all sources using the weighted mean of NGA attenuation relationships stated in Section 2.2.1 of this memorandum.

Crawford scaled the deterministic 84th-percentile 5% damped spectral response to the maximum rotated spectral using the scale factors in Section 21.1. The controlling seismic source for the project site is the California Gridded fault from periods 0 through 10 seconds. Figure IV-2 shows the 84th-percentile 5% damped spectral response for the NGA attenuation relationships.

DETERMINISTIC MCER GROUND MOTION SCALING
Per the Exception within ASCE 7-16 Supplement 1 Section 21.2.2, the deterministic ground motion response spectrum need not be calculated when the largest spectral response acceleration of the probabilistic ground motion response spectrum of 21.2.1 is less than 1.2Fa.

Fa was taken as 1.0 using Table 11.4.1 with a SS of 1.5 according to Supplement 1 Section 21.2.2.

Figure 3 in Appendix IV compares the 1.2 Fa with the probabilistic ground motion from 21.2.1 (MCER ground motion). The largest response acceleration of the probabilistic ground motion (1.15g) is less than the 1.2Fa (1.2g), therefore, the deterministic ground motion response spectrum was not further calculated.

2.2.4 SITE-SPECIFIC SPECTRAL RESPONSE ACCELERATION MCER The site-specific spectral response acceleration is defined as the lower of the probabilistic and deterministic ground motions in Section 21.2.3, however, per the Exemption within Supplement 1 Appendix B-93 8660F10 April 2023

Appendix IV
SITE-SPECIFIC HARZARD MEMORANDUM Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California November 9, 2022
6 Section 21.2.3, the site-specific MCRR ground motion response spectrum was taken as the probabilistic ground motion response spectrum of 21.2.1.

2.2.5 DESIGN RESPONSE SPECTRUM
The design response spectrum is defined in Section 21.3 as the higher of two values:

Two-thirds of the site-specific design spectral response acceleration per Section 21.2 80% of the design spectral response acceleration per Section 11.4.6 where Fa is calculated in Table 11.4-1 and Fv = 2.5 for S1 > 0.2 for Site Class D Crawford first calculated the design spectral response acceleration by taking 2/3 of the sitespecific response acceleration MCER as shown in Figure IV-4.

Crawford then calculated the design response accelerations per Section 11.4.6 with Fa = 1.0 and Fv = 2.5 and reduced the spectral accelerations by 80% to adjust for the minimum design spectral accelerations for Site Class D. We then compared Section 11.4.6 design spectral accelerations for Site Class D with our site-specific design spectral response accelerations (Figure IV-6). The reduced design spectral response accelerations based on Chapter 11.4 controlled at all periods.

The design response spectrum is shown on Figure IV-5 and Table 3.

Appendix B-94 8660F10 April 2023

Appendix IV
SITE-SPECIFIC HARZARD MEMORANDUM Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California November 9, 2022
7 Table 3: Design Response Spectrum
Period, s Sa, g

0.005 0.42

0.05 0.56

0.1 0.72

0.19 1

0.2 1

0.3 1

0.4 1

0.5 1

0.75 1

0.96 1

1.0 0.96

2.0 0.48

3.0 0.32

4.0 0.24

5.0 0.19

6.0 0.16

7.0 0.14

8.0 0.12

9.0 0.1

10.0 0.08

2.2.6 DESIGN ACCELERATION PARAMETERS
Design acceleration parameters were calculated in accordance with Section 21.4. The SDS value was taken as 90% the peak spectral acceleration value from periods 0.2 to 5 seconds. The SD1 value was taken as the maximum product of T*Sa (period * spectral acceleration) from periods 1 to 5 seconds. Per Section 21.4, the SDS and SD1 values cannot be less than 80% of the SDS and SD1 calculated from Section 11.4.5. The SDS and SD1 values in Section 11.4.5 were calculated from using Fa = 1.0 and Fv = 2.5 for a Site Class D, as given in Section 21.3.

SMS and SM1 were calculated as 1.5 times SDS and SD1, respectively. Per Section 21.4, the SMS and SM1 values cannot be less than 80% of the SMS and SM1 calculated from Section 11.4.3. The SMS and SM1 values in Section 11.4.3 was calculated from using Fa = 1.0 and Fv = 2.5 for a Site Class D, as given in Section 21.3.

The design acceleration parameters are summarized in Table 4.

Appendix B-95 8660F10 April 2023

Appendix IV
SITE-SPECIFIC HARZARD MEMORANDUM Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California November 9, 2022
8 Table 4: Preliminary Horizontal Site-Specific Spectral Accelerations

2.2.7 MAXIMUM CONSIDERED EARTHQUAKE MCEG PEAK GROUND

ACCELERATION (PGA)
A. PROBABILISTIC MCEG PGA
Per Section 21.5.1, the probabilistic geometric mean PGA shall be taken as geometric mean peak ground acceleration with a 2% probability of exceedance within a 50-year period. The probabilistic MCEG PGA is 0.46g.

B. DETERMINISTIC MCEG PGA
Per Section 21.5.2, the deterministic geometric mean PGA shall be taken as the largest 84thpercentile geometric mean peak PGA but not lower than 0.5*FPGA where FPGA is determined using ASCE 7-16 Table 11.8-1 and PGA is taken as 0.5g. The deterministic MCEG PGA was taken as

0.55g.

C. SITE-SPECIFIC MCEG PGA
The site-specific MCEG PGA (PGAM) taken as the lesser of the probabilistic MCEG PGA and deterministic MCEG PGA but not less than 80% of the PGAM determined from Equation 11.8-1 in ASCE 7-16. The site-specific PGAM was taken as 0.7g.

ATTACHMENTS
Figure IV-1: Probabilistic Response Spectra
Figure IV-2: Deterministic Response Spectra
Figure IV-3: Site-Specific Probabilistic MCER Spectrum
Figure IV-4: Risk Targeted MCER vs. Design Response Spectrum Figure IV-5: Design Response Spectrum
Design Acceleration Parameter Value (g)
Design Spectral Acceleration for Short Period
(SDS) 1.004
Design Spectral Acceleration for 1 Second
Period (SD1) 0.959
MCE Spectral Response Acceleration for
Short Period (SMS) 1.506
MCE Spectral Response Acceleration for 1
Second Period (SM1) 1.438
Appendix B-96 8660F10 April 2023

Prj. No: Date: 19-503.1 City of Ukiah Recycled Water Pipeline - Phase 4 Design Project Ukiah, CA Figure IV-1 11/10/2022 Probablistic Response Spectra Horizontal Ground Motions Appendix B-97 8660F10 April 2023

Prj. No: Date: 19-503.1 City of Ukiah Recycled Water Pipeline - Phase 4 Design Project Ukiah, CA Figure IV-2 11/10/2022 Deterministic Response Spectra Horizontal Ground Motions Appendix B-98 8660F10 April 2023

Site-Specific Probabilistic MCEr Spectrum Horizontal Ground Motions 1.5 1.0 0.5 0.0 0.0 1.0 2.0 3.0 4.0 5.0 Period (s) Probabilistic Ground Motion MCEr Minimum Probabilistic Peak Spectral Acceleration (1.2Fa) Site Class D 6.0 7.0 8.0 9.0 10.0 Figure C-3 Spectral Acceleration (g)
Prj. No: Date: 19-503.1 City of Ukiah Recycled Water Pipeline - Phase 4 Design Project Ukiah, CA Figure IV-3 11/10/2022 Site Specific Deterministic MCEr Spectrum HorizontalGround Motions Appendix B-99 8660F10 April 2023

Prj. No: Date: 19-503.1 City of Ukiah Recycled Water Pipeline - Phase 4 Design Project Ukiah, CA Figure IV-4 11/10/2022 Site Specific Risk Targeted Maximum Considered Earthquake (MCEr) vs. Site Specific Design Response Spectrum Appendix B-100 8660F10 April 2023

Prj. No: Date: 19-503.1 City of Ukiah Recycled Water Pipeline - Phase 4 Design Project Ukiah, CA Figure IV-5 11/10/2022 Design Spectral Response Appendix B-101 8660F10 April 2023

Appendix B-102 8660F10 April 2023

APPENDIX C

RECYCLED WATER PIPELINE GEOTECHNICAL REPORT

DRAFT GEOTECHNICAL REPORT
City of Ukiah Recycled Water Pipeline -
Phase 4 Design Project
Ukiah, California
Prepared by:

Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
August 2021
Prepared for:

Carollo Engineers, Inc.
2700 Ygnacio Valley Road, Suite 300
Walnut Creek, CA 94598
DRAFT Appendix C-1 8660F10 April 2023

Appendix C-2 8660F10 April 2023

Corporate Office: 1100 Corporate Drive, Suite 230 | Sacramento, CA 95831 | (916) 455-4225 Modesto: 1165 Scenic Drive, Suite A | Modesto, CA 95350 | (209) 312-7668 Pleasanton: 6200 Stoneridge Mall Road, Suite 330 | Pleasanton, CA 94588 | (925) 401-3515 Rocklin: 4220 Rocklin Road, Suite 1 | Rocklin, CA 95677 | (916) 455-4225 Ukiah: 100 North Pine Street | Ukiah, CA 95482| (707) 240-4400 August 20, 2021
Crawford File No. 19-503.1
Mr. Mike Lonergan, PE
Carollo Engineers, Inc.
2700 Ygnacio Valley Road, Suite 300
Walnut Creek, CA 94598
Subject: DRAFT GEOTECHNICAL REPORT
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project Ukiah, California
Dear Mr. Lonergan,
Attached is our DRAFT Geotechnical Report for the City of Ukiah Recycled Water Pipeline – Phase 4 Design Project in Ukiah, California. We prepared this report to provide geotechnical data, conclusions, and recommendations for advancing the project to final design. Crawford & Associates, Inc. (Crawford) completed this report in accordance with our agreement dated January 18, 2019. This Draft Geotechnical Report supersedes our January 29, 2020 Draft Geotechnical Report. We will issue a final report after receiving your comments on this draft.

Please call if you have questions or require additional information.

Sincerely,
Crawford & Associates, Inc.,
Keiko Lewis, PE Benjamin Crawford, PE, GE
Project Manager Principal Geotechnical Engineer
Hailey Wagenman
Project Engineer
DRAFT Appendix C-3 8660F10 April 2023

Appendix C-4 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021

TABLE OF CONTENTS
1 INTRODUCTION .................................................................................................................... 1

1.1 PURPOSE ..................................................................................................................... 1

1.2 SCOPE OF SERVICES................................................................................................. 1 2 PROJECT DESCRIPTION ..................................................................................................... 1 3 SITE GEOLOGY .................................................................................................................... 3 4 EXPLORATION...................................................................................................................... 4 5 SURFACE AND SUBSURFACE CONDITIONS.................................................................... 6

5.1 EXISTING PAVEMENT THICKNESSES ...................................................................... 6

5.2 SOIL CONDITIONS....................................................................................................... 6

5.2.1 OPEN CUT PIPELINE ALIGNMENT ................................................................. 6

5.2.2 TRENCHLESS CROSSINGS ............................................................................ 7

5.2.3 WATER TANK AND PUMP STATION............................................................... 7

5.2.4 PEDESTRIAN BRIDGE ..................................................................................... 7

5.3 GROUNDWATER.......................................................................................................... 8 6 SCOUR CONSIDERATIONS................................................................................................. 9 7 LABORATORY TESTING...................................................................................................... 9

7.1 GEOTECHNICAL SOILS TESTING.............................................................................. 9

7.2 CORROSION TESTING RESULTS ............................................................................ 10 8 SITE SEISMICITY ................................................................................................................ 11

8.1 FAULT RUPTURE....................................................................................................... 11

8.2 SHEAR WAVE VELOCITY AND CLASSIFICATION OF SOILS................................ 11

8.3 SEISMIC DESIGN PARAMETERS............................................................................. 11

8.4 LIQUEFACTION.......................................................................................................... 11

8.4.1 PIPELINE ALIGNMENT................................................................................... 12

8.4.2 CONCRETE TANK AND PUMP STATION...................................................... 12

8.4.3 PEDESTRIAN BRIDGE OVER ORR CREEK.................................................. 12 9 CONCLUSIONS AND RECOMMENDATIONS.................................................................... 12

9.1 FOUNDATION RECOMMENDATIONS ...................................................................... 13

9.1.1 CONCRETE TANK .......................................................................................... 13

9.1.2 PUMP STATION .............................................................................................. 13

9.1.3 BRIDGE FOUNDATIONS................................................................................ 14

9.1.3.1 COMPRESSIVE RESISTANCE....................................................................... 15

9.1.3.2 LATERAL RESISTANCE................................................................................. 15

9.1.3.3 TENSION RESISTANCE................................................................................. 16

9.1.3.4 SETTLEMENT ................................................................................................. 16

9.1.3.5 NEGATIVE SKIN FRICTION ........................................................................... 17

9.1.3.6 GROUP EFFECTS .......................................................................................... 17

9.1.3.7 CONSTRUCTION CONSIDERATIONS ........................................................... 17

9.2 LATERAL EARTH PRESSURES ............................................................................... 19

9.3 GRADING.................................................................................................................... 20

9.3.1 CLEARING....................................................................................................... 20

9.3.2 SUBGRADE..................................................................................................... 20

9.3.3 OVEREXCAVATION – TANK PAD.................................................................. 20

9.3.4 OVER-OPTIMUM SOIL MOISTURE ............................................................... 21

9.3.5 BACKFILL ........................................................................................................ 21 DRAFT Appendix C-5 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021

9.3.6 IMPORT MATERIAL ........................................................................................ 21

9.4 OPEN-CUT PIPELINE RECOMMENDATIONS.......................................................... 21

9.4.1 SOIL LOADS ON RIGID BURIED PIPES........................................................ 22

9.4.2 SOIL LOADS ON FLEXIBLE BURIED PIPES ................................................. 22

9.4.3 THRUST RESTRAINT..................................................................................... 23

9.4.4 COMPOSITE MODULUS OF SOIL REACTION.............................................. 24

9.5 TRENCHLESS PIPELINE RECOMMENDATIONS .................................................... 26

9.5.1 SHAFTS........................................................................................................... 27

9.6 PAVEMENT................................................................................................................. 28

9.7 CONSTRUCTION CONSIDERATIONS ...................................................................... 29

9.7.1 DEWATERING................................................................................................. 29

9.7.2 EXCAVATABILITY........................................................................................... 29

9.7.3 SHORING AND TEMPORARY CONSTRUCTION SLOPES .......................... 29 10 LIMITATIONS....................................................................................................................... 30

REPORT TABLES
Table 1: Recycled Water Pipeline Diameters........................................................................... 2 Table 2: Subsurface Exploration Summary ............................................................................. 4 Table 3: Existing Pavement Conditions ................................................................................... 6 Table 4: Soil Conditions............................................................................................................. 7 Table 5: Subsurface Soils.......................................................................................................... 8 Table 6: Groundwater Conditions............................................................................................. 8 Table 7: Soil Corrosion Test Summary .................................................................................. 10 Table 8: Horizontal Site-Specific Spectral Accelerations..................................................... 11 Table 9: Foundation Design Data............................................................................................ 14 Table 10: Pile Data Table ......................................................................................................... 15 Table 11: Bridge Idealized Geotechnical Parameters ........................................................... 16 Table 12: Abutment Pile Head Deflection vs. Lateral Load – Abut 1 & 2 ............................ 16 Table 13: Recommended Equivalent Fluid Weight (EFW).................................................... 19 Table 14: Recommended Passive Pressure Values.............................................................. 24 Table 15: Composite Modulus of Soil Reaction Values........................................................ 25 Table 16: Trenchless Locations Bearing Capacity................................................................ 27 Table 17: Trenchless Passive Pressures ............................................................................... 28 Table 18: Pavement Sections
DRAFT .................................................................................................. 28 Appendix C-6 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021

APPENDIX I - FIGURES
Figure 1: Vicinity Map
Figure 2: Exploration Location Map
Figure 3: Geologic Map
Figure 4: Fault Activity Map

APPENDIX II
Boring Log Legend
Boring Logs

APPENDIX III
Laboratory Test Results

APPENDIX IV
Site Specific Hazard Analysis

APPENDIX V
Settle 3D Results
CIDH Nominal Resistance Graphs
LPILE Output Graphs
DRAFT Appendix C-7 8660F10 April 2023

Appendix C-8 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
1 1 INTRODUCTION

1.1 PURPOSE
Crawford & Associates, Inc. (Crawford) prepared this DRAFT Geotechnical Report for the City of Ukiah Recycled Water Pipeline – Phase 4 Design Project in Ukiah, California. This report is to provide geotechnical and geologic data and provide conclusions and recommendations for design aspects of the project. This report supersedes our January 29, 2020 Draft Geotechnical Report. We will issue a final report after receiving comment on this draft report.

1.2 SCOPE OF SERVICES
To prepare this report, Crawford:
• Reviewed geologic, soils, and seismic maps pertaining to the alignment corridor; • Discussed the project with Carollo engineers Mike Lonergan, P.E., and Jason Benson, P.E.;
• Reviewed available historical subsurface data;
• Drilled, logged, and sampled 24 exploratory borings in 2019 along the proposed pipeline alignment, trenchless crossings, and structure locations to a maximum depth of about

51.5 feet below ground surface (bgs) in Borings R-19-004 and R-19-017; • Drilled, logged, and sampled three exploratory borings in 2020 at proposed structure locations to a maximum depth of about 81.5 feet bgs in Boring R-20-002; • Performed laboratory testing on soil samples recovered from the field explorations in 2019 and 2020;
• Reviewed “City of Ukiah Improvement Plans for Recycled Water Project Phase 4,” prepared by Carollo dated June 2019;
• Reviewed preliminary “Pump Station and Storage Site Plan” for the proposed water tank prepared by Carollo (undated);
• Performed geotechnical engineering analysis for design and construction of the pipeline alignments, site specific analysis for the proposed storage tank, and foundation elements for the proposed storage tank, and pedestrian bridge at Orr Creek; and • Developed conclusions and recommendations based on the data and test results. 2 PROJECT DESCRIPTION
The City of Ukiah plans to construct a recycled water system pipeline to serve agricultural and urban irrigation and frost protection demand throughout the city. The project will convey recycled water from local municipal treatment plants to the surrounding areas of Ukiah. The project vicinity and approximate alignment is shown on Figure 1 in Appendix I.

Currently, the overall recycled water pipeline project has been separated into four phases for design and construction. At the time of this report the first 3 phases have been designed.

Phase 4 of the project – the focus of this report – will collect (in a new storage tank) and convey recycled water from the City water treatment plant to the surrounding areas of Ukiah, west of Highway (Hwy) 101.

DRAFT Appendix C-9 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
2 More specifically, the Phase 4 portion of the project will tie into existing pipeline at the City Water Treatment Plant located about 1,000 feet east of Hwy 101. The pipeline alignment will:
• Travel west from the treatment plant, with a trenchless crossing underneath Hwy 101, towards Brush Street;
• Travel west along Brush Street for another 2,000 feet undergoing a second trenchless crossing along underneath a railroad crossing between Mazzoni Street and Orr Street; • Brush Street transitions into Low Gap Road after Mazzoni Street and the alignment heads west following Low Gap Road until Despina Drive;
• At Despina Drive, the pipeline travels north approximately 1,000 feet and terminates at the Ukiah High School;
• At the intersection of Low Gap Road and North Bush Street, the pipeline breaks away into two segments heading north and south along North Brush Street. The north segment turns east onto Arlington Drive to terminate at the Ukiah Fairgrounds Park. The south segment turns west through Pomolita Field and crosses over Orr Creek supported on a new single-span pedestrian bridge; and
• Travel through sections of the Ukiah Valley Golf Course and terminates near the Anton Stadium.

The pipeline will be about 20,000 linear feet of PVC pipe with the diameters below in Table 1 and constructed with a minimum of 4 feet of cover. Figure 2 in Appendix I shows the pipeline alignment with stationing.

Table 1: Recycled Water Pipeline Diameters
Pipeline Location Pipeline Stationing Pipeline Outer Diameter (in) Bush St and Low Gap Rd A10+00 to A58+00 18
Low Gap Rd and Despina Dr A58+00 to A90+20 10
N Bush St, Arlington Dr and
N Pine St B10+00 to B25+90 4
N Bush St, and the Golf
Course C10+00 to C31+20 12
The Golf Course, Maple Ave
and Club House Dr C31+20 to C52+40 6
Club House Dr and Park Blvd C52+40 to C66+50 4
N Bush St D10+00 to D15+40 4
The Golf Course E10+00 to E22+28 10
Key project components include:
• About 20,000 lineal feet of open-cut trench along Brush Street, Low Gap Road, North Bush Street, Arlington Drive, North Pine Street, Despina Drive, Maple Avenue, Clubhouse Drive, Park Boulevard, Pomolita Field, and through sections of the Ukiah Valley Golf Course;
DRAFT Appendix C-10 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
3 • Trenchless crossings at Hwy 101 and the railroad crossing along Brush Street, east of Mazzoni Street;
• 2 MG domed roof concrete reservoir tank (approximately 120 feet in diameter with a height of ±25 feet), partially buried, supported on a ring foundation located at the City water treatment plant;
• Pump station, partially buried, supported on mat foundation; • New single-span pedestrian bridge supported on cast-in-drilled-hole (CIDH) piles crossing over Orr Creek.

The new pedestrian bridge across Orr Creek is proposed to be 78 feet long by 12 feet wide, premanufactured rail car bridge along a similar alignment to the existing bridge. The new pedestrian bridge will clear span the channel with abutments set around 5 feet behind the existing bridge abutments and be supported on pile foundations. Each abutment will be supported on two 36-inch diameter cast-in-drilled-holes (CIDH) pile foundations spaced 9 feet.

The new bridge deck grade is planned to be 6-inches above the top of the existing bridge foundations. The new bridge approaches are anticipated to require only nominal new fill (1±foot). The new pedestrian bridge will carry the proposed pipeline over Orr Creek 3 SITE GEOLOGY
The project is within the Coast Ranges Geomorphic Province of California1, which is characterized by a series of northwest trending mountain ranges sub-parallel to the San Andres Fault. The Coast Ranges are composed of thick Mesozoic and Cenozoic sedimentary strata.

The northern Coast Ranges are dominated by the irregular, knobby, landslide-topography of the Franciscan Complex. The project site is located within the Ukiah Valley, an alluvial valley situated within the Coast Ranges.

Published regional geologic mapping2 shows surface materials as three distinct geologic units in the region that includes the project. These consist of:
• Quaternary age Alluvium,
• Quaternary (Pleistocene) age Non-marine Terrace Deposits, and • Undivided Cretaceous age Marine Sedimentary Rock.

Quaternary age Alluvium are the youngest deposits and are mapped to occur along the eastern portion of the project alignment (from the railroad crossing at Brush Street to the treatment plant) as well as the southeast portion of the Ukiah Municipal Golf Course. The alluvium consists of predominately unconsolidated gravel, sand, silt, and clay deposited in channels and on floodplains of the Russian River (located approximately 600 feet east of the project alignment). Recent alluvium is thickest in the central portion of the Ukiah basin and extends from the surface to depths of 50 to 80 feet.3

1 California Geologic Survey (2002), California Geomorphic Province, Note 36 2 Jennings, C.W. and Strand, R.G., Geologic Map of California: Ukiah Sheet, 1960, Division of Mines and Geology 3 California Department of Water Resources (2004), Ukiah Valley Ground Water Basin, California Groundwater Bulletin 118
DRAFT Appendix C-11 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
4 Quaternary (Pleistocene) age non-marine terrace deposits are the predominant surficial deposits mapped along the project alignment (west of the Railroad crossing on Brush Street).

These deposits generally consist of gravelly clay to sandy/silty gravel up to 200 feet thick4 .

Terrace deposits generally overlie older (Pliocene and Pleistocene-age) alluvium and occur discontinuously along the Ukiah Valley.

Undivided Cretaceous aged Marine Sedimentary Rock is mapped west of the project alignments. This unit is comprised predominantly of sandstone, shale, and conglomerate deposits.

We present a Geologic Map as Figure 3 in Appendix I.
4 EXPLORATION
Crawford retained Geo-Ex Subsurface Exploration (Geo-Ex) to drill twenty-four exploratory borings in 2019 and three exploratory borings in 2020 along the proposed pipeline alignment, trenchless crossings, and structure locations. Table 2 provides a subsurface exploration summary.

Table 2: Subsurface Exploration Summary
CAInc Exploratory Borings (2019)
Boring
Number
Completion
Date
Drill Rig Type/ Drilling
Equipment Type
Hammer
Type
Hammer
Efficiency
(%)
Approx.

Ground
Surface
Elevation
(ft)
Boring
Depth
(ft)
R-19-001 03/14/2021 CME 75 (Track Mounted)
Auto

70.01 608.0 50.5
R-19-002 03/22/2019 CME 55 (Truck Mounted) 77.02 603.2 41.5 A-19-003 03/20/2019 CME 75 (Track Mounted) 70.01 605.0 21.3 R-19-004 03/21/2019
CME 55 (Truck Mounted) 77.02
613.0 51.5
A-19-005 03/21/2019 638.5 21.6
A-19-006 03/20/2019 649.1 21.0
A-19-007 03/20/2019 654.3 21.5
A-19-008 03/20/2019 668.0 21.5
R-19-009 03/18/2019 CME 75 (Track Mounted) 70.01 600.0 35.5 A-19-010 03/20/2019
CME 55 (Truck Mounted) 77.02
687.3 21.5
A-19-011 03/20/2019 653.3 21.5
A-19-012 03/21/2019 654.9 21.5
A-19-013 03/21/2019
CME 75 (Track Mounted) 70.01
641.4 21.5
A-19-014 03/22/2019 638.2 21.3
A-19-015 03/21/2019 668.7 20.9
A-19-016 03/21/2019 680.2 21.5
4 California Department of Water Resources (2004), Ukiah Valley Ground Water Basin, California Groundwater Bulletin 118
DRAFT Appendix C-12 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
5 CAInc Exploratory Borings (2019)
Boring
Number
Completion
Date
Drill Rig Type/ Drilling
Equipment Type
Hammer
Type
Hammer
Efficiency
(%)
Approx.

Ground
Surface
Elevation
(ft)
Boring
Depth
(ft)
R-19-017 03/19/2019
CME 75 (Track Mounted) Auto 70.01
601.5 51.5
A-19-018 03/22/2019 704.7 20.8
A-19-019 03/22/2019 709.1 7.8
A-19-020 03/22/2019 632.5 21.5
R-19-021 03/18/2019 596.7 36.0
A-19-022 03/21/2019 695.1 21.5
A-19-023 03/21/2019 646.1 21.5
A-19-024 03/22/2019 CME 55 (Truck Mounted) 77.02 613.2 46.5 CAInc Exploratory Borings (2020)
A-20-001 11/30/2020
CME 75 (Track Mounted) Auto 89.13
799.5 60.0
R-20-002 12/02/2020 634.4 81.5
R-20-003 12/03/2020 636.2 76.5

1. A hammer energy calibration test was not performed specifically for this project/site; however, a previous hammer energy testing result provided by Geo-Ex found the hammer to have an energy efficiency of 70.1%.

2. A hammer energy calibration test was not performed specifically for this project/site; however, a previous hammer energy testing result provided by Geo-Ex found the hammer to have an energy efficiency of 77.0%.

3. A hammer energy calibration test was not performed specifically for this project/site; however, a previous hammer energy testing result provided by Geo-Ex found the hammer to have an energy efficiency of 89.1%.

Soil samples were recovered by means of a 2.0-inch O.D. “Standard Penetration” split-spoon sampler with 1.4-inch stainless steel liners and a 3.0-inch O.D. “Modified California” split-spoon sampler with 2.4-inch stainless steel liners. Both samplers were advanced with standard 350 ftlb striking force using a 140 lb. automatic hammer and a drop height of 30 inches. Sampler penetration resistance was recorded to provide a field measure of relative densities and can be correlated to soils strength and bearing characteristics. Consistency of cohesive soils were obtained in the field by means of pocket penetrometer. The field-recorded (uncorrected) blow counts are shown on our boring logs in Appendix II.

Crawford’s project engineers and geologists logged the exploratory borings consistent with the Unified Soil Classification System (USCS) and the 2010 Caltrans Logging Manual. Crawford retained samples from the borings in sealed constrainers for laboratory testing and reference.

Groundwater observations were recorded during drilling operations when encountered. At completion, the exploratory borings were backfilled following Mendocino County Environmental Health requirements.

The exploration boring locations were measured in the field with respect to existing site features. The boring elevations are referenced to project datum provided by Carollo. See Figure 1 in Appendix I for exploratory boring locations. The details of the borings are shown on the boring logs in Appendix II.

DRAFT Appendix C-13 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
6 5 SURFACE AND SUBSURFACE CONDITIONS

5.1 EXISTING PAVEMENT THICKNESSES
Crawford measured the pavement sections at various locations along the pipeline alignment.

We present pavement section data below.

Table 3: Existing Pavement Conditions
Boring
Number Approximate Station1 Asphalt Concrete Thickness (in) Aggregate Base
Thickness (in)
R-19-004 A34+37.6 Lt 1.3 5 6
A-19-005 A45+45.1 Lt 15.5 3 3
A-19-006 A54+40.8 Lt 53.0 3 3
A-19-007 A67+16.5 Lt 15.3 3 3
A-19-008 A74+10.6 Lt 12.0 2 3
A-19-010 A88+46.8 Rt 15.7 3 3
A-19-011 B24+50.3 Rt 15.4 3 5
A-19-012 B15+29.6 Rt 19.7 3 3
A-19-013 C15+62.3 Lt 17.8 3 3
A-19-016 C44+24.5 Lt 70.3 3 3
A-19-018 C58+94.6 Lt 10.4 2 2
A-19-019 C62+97.8 Lt 44.4 2 0
A-19-020 D16+34.8 Lt 10.3 3 3
A-19-022 C51+31.3 Lt 50.1 3 3
R-19-024 A32+87.8 Lt 34.4 4 3
1 Stations correlate with Figure 2 attached.

5.2 SOIL CONDITIONS
Based on our subsurface investigation, the soils encountered along the alignment seem to generally agree with published geologic maps. We summarize soil descriptions for sections of the project alignment below. Refer to the Boring Logs in Appendix II for more detailed soil conditions.

5.2.1 OPEN CUT PIPELINE ALIGNMENT
The table below describes the soil conditions encountered at the surface down to the total depths of the borings with exception to the Undivided Cretaceous Marine deposit which was encountered at 7 feet bgs in A-19-019.

DRAFT Appendix C-14 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
7 Table 4: Soil Conditions
Approximate Station1 Geologic Deposit Description
A12+00 to A42+00 Quaternary age Alluvium Gravel, sand, silt and clays A42+00 to A90+00;
B10+00 to B25+00;
C10+00 to C57+00;
D10+00 to D15+00; and
E10+00 to E27+00
Quaternary age non-marine
terrace Gravelly clay to sandy/silty gravel
C57+00 to C66+00 Undivided Cretaceous Marine Sedimentary rock (Claystone) 1 Stations correlate with Figure 2 attached.

5.2.2 TRENCHLESS CROSSINGS
In this portion of the alignment, we encountered Quaternary age alluvium that consists of unconsolidated gravel, sand, silt and clay. In general, soil conditions were as follows:
• At the trenchless crossing for Hwy 101, we encountered approximately 30 feet of stiff to very stiff lean clay. The clay is underlain by very dense, poorly graded gravel with clay and sand to the maximum depth of our borings (50.5 feet). • At the trenchless crossing for the railroad, we encountered approximately 19 feet of soft to hard, sandy, lean clay and lean clay with sand. In Boring R-19-024, we encountered a loose, poorly graded sand with clay and gravel at a depth of approximately 8 to 13 feet. This correlates with a soft, sandy, lean clay in our other boring for the crossing (R19-004) at a similar depth. Below a depth of approximately 19 feet, we encountered predominately dense to very dense, poorly graded gravel with sand to a depth of 38 to 41 feet. The gravel is underlain by stiff to very stiff, sandy, lean clay and dense, clayey sand to the maximum depth of our borings (51.5 feet).

5.2.3 WATER TANK AND PUMP STATION
Soils at the concrete tank and pump station at the City water treatment plant are variable. In general, we encountered a soil profile that consists of 28 to 30 feet of medium dense to dense, sand, silty sand, and gravel that is underlain by very dense, gravel, clayey sand, and sand to the maximum depth of our borings (51.5 feet). The water tank and pump station site have existing basins, with unknown depths, that fall within the footprint of the improvements. Fill material may be required to provide level pads around the proposed structures.

5.2.4 PEDESTRIAN BRIDGE
Based on the exploratory boring data, subsurface soils at the proposed pedestrian bridge crossing over Orr Creek can be divided into three general soil units, as follows in Table 5.

DRAFT Appendix C-15 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
8 Table 5: Subsurface Soils
Soil
Unit
Depth
(ft)
Elevation
(ft) Soil Description
1 0.0 –

10.0 636 – 627 Hard, brown, moist, lean clay (CL) and dense silty sand (SM) 2 10.0 –

38.0 627 – 598
Loose to very dense, yellowish brown to reddish brown, dry to wet, silty / clayey gravel (GC), silty / clayey sand (SC), and hard gravelly lean clay (CL)
3 38.0 –

81.5 598 – 553 Medium stiff to hard, yellowish brown to reddish brown, moist, lean clay to gravelly lean clay (CL) and very dense clayey gravel (GC)

5.3 GROUNDWATER
Table 6 depicts the groundwater conditions observed in the field. We also include data from California Department of Water Resources (DWR) wells in the vicinity below. DWR elevations reference NAVD88.

Table 6: Groundwater Conditions
Consultant/
Source Boring/Well Number Date Measured
Approximate
Location
Groundwater
Depth (ft)
Groundwater
Elevation (ft) 1
Crawford R-19-004 3/21/19 A34+37.6 Lt 1.3 7.6 605.4
Crawford R-19-009 3/17/19 In Water Treatment
Facility 14.0 586.0
Crawford A-19-012 3/21/19 B15+29.6 Rt 19.7 17.0 637.9
Crawford A-19-014 3/22/19 C25+10 Rt 76.7 12.0 626.2
Crawford A-19-015 3/21/19 C36+08.6 Rt 56.8 18.0 650.7
Crawford A-19-016 3/21/19 C44+24.5 Lt 70.3 9.0 671.2
Crawford A-19-020 3/22/19 D16+34.8 Lt 10.3 7.0 625.5
Crawford A-19-022 3/21/19 C51+31.3 Lt 50.1 15.0 680.1
Crawford A-19-023 3/21/19 E22+29.7 Lt 12.3 9.0 637.1
Crawford R-20-002 12/02/20 TBD 17.0 617.4
Crawford R-20-003 12/03/20 TBD 18.5 617.7
Taber Well WTP-1 5/15/2009 Southern Terminus
of City Well Rd 17.5 unknown
DWR 391586N1232003W002 5/7/19 (39.158611, -
123.200278) 65.4 542.62
DWR 391409N1231982W001 4/13/16 (39.140931, -
123.198165) 39.0 561.02
DWR 391411N1231983W001 5/7/19 (39.141111, -
123.198333) 49.8 544.22
1 Survey data provided by Carollo Engineering. 2
Using the Department of Water Resources; http://wdl.water.ca.gov/waterdatalibrary/. Accessed July 9, 2019.

DRAFT Appendix C-16 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
9 The above groundwater conditions are based on field observations during our exploration and published data. The water treatment plant is located adjacent to (west of) the Russian River with Orrs Creek located just south of the water treatment plant and nearby portions of the alignment.

The southernmost portion of the pipeline alignment is in the vicinity of Gibson Creek (south of Anton Stadium). Due to the close proximity of the pipeline to these features, groundwater elevation will likely be influenced by the water levels in the Russian River, Orrs Creek and Gibson Creek. Groundwater conditions will also fluctuate with seasonal precipitation and land use. The above data indicates that groundwater likely will not adversely impact the majority of pipeline construction but may adversely impact pump station construction and trenchless crossings. Dewatering is discussed in Section 8 of this report.

We recognize that the high groundwater levels encountered in our field exploration reflect groundwater conditions after a “heavy” wet season. Groundwater levels will drop during the dry season. Published data on DWR’s Water Data Library5 indicate groundwater readings historically fluctuate approximately 5 feet between wet and dry seasons. 6 SCOUR CONSIDERATIONS
A study was not conducted to evaluate the potential for scour within the limits of the bridge crossing at Orr Creek. For the purpose of this study, we assumed a scour elevation of 621 feet (approximately 2 feet below the bottom of the creek channel) at the proposed abutment locations for foundation analysis.
7 LABORATORY TESTING

7.1 GEOTECHNICAL SOILS TESTING
We completed the following laboratory tests on representative soil samples obtained from the exploratory borings:
• Moisture Content / Dry Density (ASTM D2216 / D2937)
• Particle Size Analysis (ASTM D422)
• No. 200 Sieve Wash (ASTM D1140)
• Atterberg Limits (ASTM D4318)
• Unconfined Compressive Strength (ASTM D2166)
• Direct Shear Strength (ASTM D3080)
• Sulfate/Chloride Content (CTM 417/422)
• pH/Minimum Resistivity (CTM 643)
• R-value (CTM 301)
We show test results on the logs of the borings and in Appendix III. 5 http://www.water.ca.gov/waterdatalibrary/index.cfm
DRAFT Appendix C-17 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
10 7.2 CORROSION TESTING RESULTS
The USDA Web Soil Survey6 estimates the project alignment to be moderately to highly corrosive to ferrous elements and low to moderately corrosive to cementitious elements. Table 7 summarizes the results of soil corrosivity tests on samples from our exploratory borings.

Table 7: Soil Corrosion Test Summary
Boring /
Sample
Number
Depth
(ft)
Approximate
Station pH
Minimum
Resistivity
(Ohm-cm)
Chloride
Content
(ppm)
Sulfate
Content
(ppm)
R-19-002 / 2 11.0 A13+98.8 Rt 35.8 6.14 2,650 1.5 5.7
R-19-004 Bulk 0-5.0 A34+37.6 Lt 1.3 6.89 3,480 1.4 15.0 A-19-008 / 1 6.0 A74+10.6 Lt 12.0 5.71 10,990 0.5 5.9
A-19-018 / 1 3.5 C58+94.6 Lt 10.4 4.90 2,950 1.7 17.6
A-20-001 / 1 3.5 TBD 4.52 4,820 4.3 1.0
R-20-003 / 3 8.5 TBD 6.06 780 120.1 169.7
According to Caltrans Corrosion Guidelines7
, a site is considered corrosive to foundation
elements if one or more of the following conditions exist:
• pH is 5.5 or less
• Chloride concentration is greater than or equal to 500 parts per million (ppm), • Sulfate concentration is greater than or equal to 1500 ppm Based on the soil types we encountered, test results, Caltrans guidelines, and USDA mapping, the soils in A-19-018-1A and A-21-001-1A are considered “corrosive” to ferrous materials. The soils along the project alignment are considered “non-corrosive” to cementitious materials.

According to Caltrans guidelines, with the exception to MSE wall design, minimum resistivity is not included as a parameter to define a corrosive environment for structures. MSE walls do include the resistivity parameter in defining a potentially corrosive backfill material. Resistivity can serve as an indicator parameter of the possible presence of soluble salts (chlorides and sulfates), with a minimum resistivity value of 1,100 ohm-cm or less indicating the potential presence of high quantities of soluble salts (higher propensity for corrosion), and thus requiring additional testing.

These tests are only an indicator of soil corrosion potential. Section 12 of the Caltrans Corrosion Guidelines provided information regarding corrosion mitigation measures for structural elements and lists additional Caltrans guidelines documents regarding corrosion mitigation if deemed appropriate by the designer. The designer should also consult with a corrosion engineer if these values are considered significant.
6 https://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx 7 California Department of Transportation, Corrosion Guidelines, Version 3.0, March 2018 DRAFT Appendix C-18 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
11 8 SITE SEISMICITY

8.1 FAULT RUPTURE
The site does not lie within an Alquist–Priolo Earthquake Fault Zone and no known active faults are mapped within or through the project area. The California Geologic Survey (CGS) considers a fault to be active if it has shown movement one or more times during the Holocene period, defined as the last 11,700 years. According to the CGS, the closest active fault is the Maacama Fault Zone north section (Maacama fault) located about one mile northeast of the eastern-most point of the project area in the water treatment plant where the tank and pump stations will be.

8.2 SHEAR WAVE VELOCITY AND CLASSIFICATION OF SOILS
For this site/project, a correlated shear wave velocity (VS30) in the upper 100 ft of the soil profile equal to 290 meters per second (about 950 ft/sec) is considered appropriate for use in design.

This value corresponds to a “soft/loose soil profile” with 180 m/s < Vs < 360 m/s (Soil Profile Type F) for the upper 100 feet of the soil profile.

The VS30 value was determined for this site based on the soil data obtained from our 2019 test boring data and correlations with SPT N-values (or equivalent SPT N-values) corrected for hammer efficiency using the equations outlined in Appendix A of Caltrans’ Methodology for Developing Design Response Spectrum for Use in Seismic Design Recommendations, November 2012.

8.3 SEISMIC DESIGN PARAMETERS
Crawford completed a site-specific hazard analysis according to ASCE 7-16 Section 11.4.8. We recommending using the following site-specific hazard values provided in Tables 8.

Table 8: Horizontal Site-Specific Spectral Accelerations Design Acceleration Parameter Value (g)
Design Spectral Acceleration for Short Period (SDS) 1.48 Design Spectral Acceleration for 1 Second Period (SD1) 1.58 MCE Spectral Response Acceleration for Short Period (SMS) 2.22 MCE Spectral Response Acceleration for 1 Second Period (SM1) 2.37 See Appendix IV for the detailed site-specific hazard analysis.

8.4 LIQUEFACTION
Soil liquefaction can occur when saturated, relatively loose sand and specific soft, fine-grained saturated soils are subject to ground shaking strong enough to create soil particle separation that results from increased pore pressure. This separation and subsequent pore pressure dissipation can lead to decreased soil shear strength and settlement. Liquefaction is known to DRAFT Appendix C-19 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
12 occur in soils ranging from low plasticity silts to gravels. However, soils most susceptible to liquefaction are clean sands to silty sands and non-plastic silts.

To evaluate the potential for soil liquefaction to occur at the site, Crawford used the simplified procedure outlined by Youd et al. (2001)8 and guidelines consistent with liquefaction evaluation outlined in the Caltrans Geotechnical Manual (December 2014), the 2019 and 2020 boring data, laboratory test results, a Magnitude (M) of 7.2, and a Peak Ground Acceleration (PGA) of 0.90g.

In our analysis, we modeled the groundwater elevation in each boring at the depth where we encountered it respectively. The maximum moment magnitude was determined using the USGS Deaggregation Unified Hazard Tool9
.

8.4.1 PIPELINE ALIGNMENT
Based on soil and groundwater conditions encountered and current industry accepted liquefaction evaluation methods the potential for liquefaction along the pipeline alignment is low.

8.4.2 CONCRETE TANK AND PUMP STATION
Based on the soil and groundwater conditions encountered, the potential for liquefaction exists within the upper 50 feet of soils at the site in borings R-19-009, R-19-017 and R-19-021 in the saturated gravels and sands. Based on our boring data, there is a trend that shows reduced liquefaction potential and less liquefaction induced settlement towards the south end of the site.

Our analysis shows that liquefaction induced settlement on the order of 1 to 2 inches can be expected at the tank location; with differential settlement on the order of ½ to 1 inch across the tank.

8.4.3 PEDESTRIAN BRIDGE OVER ORR CREEK
Based on the soil and groundwater conditions encountered the potential for liquefaction exists within the upper 50 feet of soils at the site in Boring R-20-002 and R-20-003 in the saturated gravels. Our analysis shows that liquefaction induced settlement on the order of 1 to 1.5 inches can be expected at this location; with differential settlement on the order of ½ to ¾-inches across the bridge. We account for the potential liquefaction settlement and associated downdrag in our pile analysis.
9 CONCLUSIONS AND RECOMMENDATIONS
We conclude that the alignment is suitable for construction of the proposed tank, pump station, pipeline, and pedestrian bridge crossing provided the recommendations presented below are included in design and construction. Based on the above information and our analysis, the key geotechnical considerations associated with design and construction of this project included presence of clayey sands and gravels along the alignment which may cause caving, heavy tank loads and potential for settlement, and the potential for liquefaction settlement at the concrete storage tank, pump station, and pedestrian bridge crossing over Orr Creek. 8 Youd, T. L., et al, 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, pp. 817-833. 9 https://earthquake.usgs.gov/hazards/interactive/ accessed July 29, 2021.

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DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
13 9.1 FOUNDATION RECOMMENDATIONS

9.1.1 CONCRETE TANK
We understand the tank will be supported by perimeter ring foundations, and concrete slab-ongrade floor. Based on the information provided by DN Tanks (loading distribution dated July 14, 2021), we understand tank loading will result in design bearing capacities of 2,000 psf uniformly distributed along the belly of the tank and a bearing capacity ranging from 4,400 psf to 1,200 psf along the inner and outer perimeter ring foundation; respectively. We also understand the tank will be partially buried, likely to at least the elevation of the bottom of the existing basin (elevation 597 feet). In addition, Crawford recommends a five-foot overexcavation and compaction (down to elevation 592 feet) to provide firm, uniform support to the tank (recommendations for the overexcavation and compaction is provided in Section 9.3.3 of this report). In general, the site is capable of supporting the tank design loads provided.

Crawford performed settlement analysis using RocScience 3D Settlement computer program and the provided bearing capacities, a tank diameter of 120-foot (based on “AWWA D110 Type I Cast In Place Concrete Storage Tank Plans,” undated), tank bottom installed near an elevation of 597 feet (existing grade at R-19-021), perimeter foundations embedded a minimum of 18 inches below lowest adjacent grade and 5 ft wide. The tank was analyzed using both borings R19-017 and R-19-021. We provide results of our settlement analysis in Appendix V. In general, consolidation settlement will be negligible due the presence of coarse-grained materials. We expect about 2 inches of immediate settlement below the tank with a differential settlement of about 1 inch from the center of the tank to the perimeter (about 60 feet). Based on the nature of the onsite soils, we expect 50% to 65% of the immediate settlement to occur during construction. However, with liquefaction we expect approximately 1 to 2 inches of additional liquefaction settlement below the tank with a differential settlement of about ½ to 1 inch.

Lateral forces may be resisted by friction developed between the base of the footing and the underlying soil. Use a coefficient of friction of 0.70 for concrete cast against cohesionless soil to resist sliding. Additional lateral resistance may be provided by assuming a passive pressure based on an equivalent fluid weight of 210 pcf. The passive capacity reduces to an equivalent fluid weight of 170 pcf during a seismic event. In designing the structure to resist lateral loads, the upper 12 inches of soil should be ignored.

9.1.2 PUMP STATION
We understand that the pump station foundation dimensions and loads are still being determined, however support of the new pump station is available using a mat foundation provided they are 12 inches wide and extend a minimum of 18 inches below lowest adjacent grade. Provided that the mat foundation is designed to evenly distribute the pump station contents, equipment, and structure, an allowable bearing capacity of 3,000 psf may be used for design. The bearing capacity value may be increased by one-third if wind and/or seismic loads are included. Total and differential foundation settlement is expected to be less than 1 inch and ½ inch, respectively.

Lateral forces may be resisted by friction developed between the base of the footing and the underlying soil. Use a coefficient of friction of 0.70 for concrete cast against cohesionless soil to DRAFT Appendix C-21 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
14 resist sliding. Additional lateral resistance may be provided by assuming a passive pressure based on an equivalent fluid weight of 210 pcf. The passive capacity reduces to an equivalent fluid weight of 170 pcf during a seismic event. In designing the structure to resist lateral loads, the upper 12 inches of soil should be ignored.

9.1.3 BRIDGE FOUNDATIONS
Based on the boring data generated for this study, site conditions are considered suitable for structure support by means of CIDH piles for the abutments established within competent soils.

Foundation support for the proposed bridge is available withing the underlying very dense and hard soil layers (Unit 2 and 3). CIDH piles can provide adequate axial capacity and minimize construction noise and vibrations.

Spread footing foundations for the bridge abutments is considered feasible, but would not be as secure as pile foundations due to the potential for liquefaction from medium dense, saturated gravels (Unit 2 materials), the potential for scour/erosion along the creek banks, and large excavations required near the creek channel. Due to the presence of dense to very dense gravel layers above specified design tip elevations, driven displacement-type concrete and steel pipe piles are likely not suitable for this site. Such piles would be expected to experience very hard driving that could result in short piles and/or pile damage. Therefore, we recommend the use of CIDH piles to support the proposed bridge structure.

The proposed bridge over Orr Creek will be supported at each abutment by two 36-inch diameter CIDH piles spaced 9 feet center-to-center (CTC). Such piles would require special installation measures due to the presence of groundwater and on-site gravely soils, including temporary casing, slurry drilling methods (with inspection tubes) and the use of minimum 24- inch diameter CIDH piles for tremie concrete placement. The foundation data and pile capacities for the 36-inch CIDH pile foundation were provided by Carollo and are presented in Table 9 below.

Table 9: Foundation Design Data
Support
No.

Design
Method Pile Type
Cut-off
Elev.
(ft)
Pile Cap
Size (ft)
Number
of Piles
per
Support
Lateral
(kips)
Compression
(kips)
B L Per
Support
Per
Pile
Abut 1 LRFD 36” CIDH Pile 633.75 6 12 2 27.7 85 42.5
Abut 2 LRFD 36” CIDH Pile 633.75 6 12 2 27.7 85 42.5
Our evaluation identifies the presence of local/isolated soil layers that are in the range of soil texture and consistency considered susceptible to liquefaction during a design earthquake event. The pile analysis and tip elevations presented below addresses the effects of liquefaction.

When using LRFD loading, we recommend applying a geotechnical resistance factor of 0.7 to the above compression loads when selecting the pile length. The foundation design recommendations for 36-inch diameter CIDH piles are summarized in Table 10 below.

DRAFT Appendix C-22 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
15 Table 10: Pile Data Table
Support
No. Pile Type
Cut-off
Elevation
(ft)
Nominal Resistance
(kips)
Design
Tip Elev.
(ft)
Specified
Tip Elev.

Compression Tension (ft)
Abut 1 36” CIDH Pile 633.75 70 NA (a) 579
(b) 588 579
Abut 2 36” CIDH Pile 633.75 70 NA (a) 579
(b) 588 579
1) Design Tip Elevations are controlled by: (a) Compression, (b) Lateral Load. 2) The Specified Tip Elevation shall not be raised above the design tip elevation. 3) The piles will be founded in competent dense/hard soils

9.1.3.1 COMPRESSIVE RESISTANCE
The side (compressive) resistance for the 36-inch CIDH pile foundations was evaluated using LRFD methods and factors from AASHTO LRFD Bridge Design Specifications10 (BDS) with Caltrans amendments to determine the design pile tip elevation. End bearing contributions to axial resistance were neglected, consistent with current Caltrans guidelines for CIDH pile design. Actual contributions to skin friction vary depending on load transfer along the pile shaft.

A geotechnical resistance factor (𝜑) of 0.7 was used to evaluate compressive resistance consistent with Caltrans amendments to AASHTO LRFD method for the CIDH piles.

Consistent with AASHTO LRFD BDS 10.8.3.5.1b and C10.8.3.5.1b (Side Resistance), the top 5 feet of the pile is excluded from contributing to geotechnical capacity. For our analysis, the bottom 5 feet of the pile is also excluded from contributing to geotechnical capacity.

We present the CIDH Pile Nominal Resistance (Axial Compression) graphs in Appendix V.

9.1.3.2 LATERAL RESISTANCE
The LPILE Version 2018.10.09 computer program was used to estimate lateral pile design loads for vertical piles which would produce approximately ¼-inch and ½-inch pile head deflection at the provided cut-off elevation assuming a fixed-head condition. For the proposed bridge, pile response in the longitudinal and transverse bridge directions was computed using elastic pile stiffness (basic modeling) with an axial compression value of 17.5 kips, approximately 1.6% steel, and a pile diameter of 36 inches. The idealized geotechnical parameters that were used in the lateral pile analysis are shown below in Table 11.
10 American Association of State Highway and Transportation Officials, AASHTO LRFD Bridge Design Specifications, 8th Edition, November 2017.

DRAFT Appendix C-23 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
16 Table 11: Bridge Idealized Geotechnical Parameters
Elevation
(ft) LPILE Soil Type
Unit
Weight
(lb/ft3)
Friction
Angle
(degrees)
Cohesion /
Residual
Strength
(psf)
Strain
Factor,
E50
(dim.)
p-y
Modulus,
k
(lb/in3)
636 to 627 Stiff Clay w/o Free Water 115 -- 4,000 0.004 -- 627 to 618 Sand (Reese) 115 36 -- -- 225
618 to 613 Sand (Reese) 53 36 -- -- 125
613 to 608 Soft Clay (Matlock) 68 -- 1,000 0.02 --
608 to 598 Sand (Reese) 68 38 -- -- 125
598 to 553 Stiff Clay w/o Free Water 63 -- 3,000 0.005 -- Notes:

1. Elevations are based on project datum.

2. Design groundwater at elev. 618 feet).

3. Unit Weight equals Total Unit Weight above the groundwater and the Buoyant Unit Weight below the groundwater.

4. Buoyant Unit Weight = Total Unit Weight - 62.4 pcf.

5. Liquefied layer modeled as soft clay with residual strength.

The results of our lateral pile analysis for both the longitudinal and transverse bridge directions for the abutments are presented in Table 12.

Table 12: Abutment Pile Head Deflection vs. Lateral Load – Abut 1 & 2 Condition Spacing Pile
Row P-multiplier Deflection, in Shear, kips
Longitudinal 3.0B 1 0.90

0.25 28.7

0.50 38.2
Transverse 3.0B
1 0.75

0.25 27.1

0.50 36.2
2 0.55

0.25 24.4

0.50 33.1
Note: B = pile diameter
The LPILE output graphs are presented in Appendix IV.

9.1.3.3 TENSION RESISTANCE
No tension demands are indicated for the pile foundations.

9.1.3.4 SETTLEMENT
For this project, the nominal resistance of the CIDH piles is designed to be derived through side resistance with no end-bearing contributions. All piles will be founded in competent materials DRAFT Appendix C-24 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
17 that consist of dense to very dense granular and medium stiff to hard cohesive layers.

Theoretically, the vertical load on the CIDH piles for this structure will not exceed the nominal side resistance of the pile shaft. Therefore, pile settlement is expected to be less than 1.0-inch for the CIDH piles. Since the piles will be embedded adequately into dense/hard soils, a detailed assessment of the pile group settlement is not considered warranted.

9.1.3.5 NEGATIVE SKIN FRICTION
We anticipate negative skin friction (downdrag) at the abutments as a result of the settlement due to liquified, saturated, medium dense granular soil layers encountered at the site.

9.1.3.6 GROUP EFFECTS
The foundation soils predominately consist of dense to very dense granular layers and medium stiff to hard cohesive layers. The pile center-to-center spacing is greater than 2.5 times the pile diameter.

According to AASHTO LRFD BDS (Section 10.7.3.9 – Resistance of Pile Groups in Compression) with California amendments:
• For Cohesive Soil – If the pile cap is in firm contact with the ground, no reduction in efficiency shall be required. If the pile cap is not in firm contact with the ground and if the soil is stiff, no reduction in efficiency shall be required. • For Granular Soil – The efficiency factor, 𝜂, shall be 1.0 where the pile cap is or is not in contact with the ground for a center-to-center pile spacing of 2.5 diameters or greater.

Therefore, no reduction in efficiency is required and a group efficiency factor (𝜂) of 1.0 was used in our compressive resistance pile analysis.

9.1.3.7 CONSTRUCTION CONSIDERATIONS
Consideration for CIDH pile installation/excavation for this site/project includes:
• Potential for caving soils due to presence of loose to medium dense soil layers within pile foundation depths,
• Presence of gravel layers withing pile foundation depths, and • Presence of groundwater within pile foundation depths.

Due to the anticipated presence of groundwater around elev. 618 feet, we recommend installing CIDH piles by the “wet” method, including slurry drilling and concrete placed under slurry using tremie pipe. We recommend constructing CIDH piles in conformance with Section 49-3 of the Caltrans Standard Specifications11, Revised Standard Specifications, and Standard Special Provisions. The slurry construction method (“wet” method) requires placement of inspection tubes to permit Gamma-Gamma Logging (GGL) and Cross-hole Sonic Logging (CSL) of the CIDH pile.

For CIDH piles with center-to-center spacing less than 4.0 diameters, the sequence of shaft installation should be specified in the contract documents (Section 10.8.1.2, California Amendments to AASHTO LRFD BDS).
11 California Department of Transportation, Standard Specifications, 2018.

DRAFT Appendix C-25 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
18 The contractor should anticipate variable drilling conditions in all CIDH pile excavations due to the presence of medium stiff to hard cohesive soils (lean clay) and loose to very dense noncohesive soils (sand and gravel) . Variable drilling conditions may include alternating between soft and hard drilling techniques.

To reduce the magnitude of downdrag, permanent casing for CIDH pile can be installed to/below the bottom of the liquefiable layer. At the abutment locations, permanent steel casing is permissible no lower than elev. 608 feet. The permanent steel casing may be specified as either a permanent smooth-wall casing or a Corrugated Metal Pipe (CMP). The permanent steel casing should be at least 8-inches greater than the CIDH pile to help prevent binding of the drilling tool. The permanent steel casing may be placed in drilled hole, and annual space backfilled with grout (Standard Specifications Section 49-3.02B(5), 49-3.02C(6). It is also permissible to drill/oscillate/rotate the permanent casing into place. Installation by driving or vibration is not recommended.

The contractor is responsible for the design and installation of temporary casing (if used), including actual length(s) and diameter(s), to install CIDH piles according to the above specifications without defects or damage to existing utilities/facilities.

Temporary casing (if used), should be noncorrugated steel with smooth surfaces and the casing diameter should be at least 8-inches greater than the CIDH pile to help prevent binding of the drilling tool. Install temporary casing below the specified pile tip elevation is not permissible.

Temporary casing should be removed during placement of concrete.

The project specifications should explicitly exclude vibration and impact installations methods if noise or vibrations are of concern or otherwise not allowed due to environmental constraints, proximity of nearby residences or to protect existing facilities (e.g., underground utilities potentially susceptible to vibration damage).

If an oscillator or rotator is used to construct the CIDH piles:
• The contractor should be prepared for subsurface conditions that include layers of clays and coarse granular materials (e.g., sand, gravel).
• The contractor should maintain a positive fluid head within the drill road at all times. The fluid should be mineral or polymer slurry; water is not permitted. • The contractor is to maintain a minimum 10-foot soil plug within the drill rod. The 10-foot plug is to be maintained until the drill rod reaches the specified tip elevation. It may be necessary to extend the casing below the bottom of the pile tip to maintain a soil plug to help maintain stability at the base.
• The contractor must provide access to the top of the oscillator/rotator drill rod, as requested by the Engineer, to verify the positive head and minimum soil plug are being maintained.
• It is important to maintain continuous rotation/oscillation and place rebar/concrete expeditiously to avoid lockup. The contractor should take into account the work window allowed by the project specifications to install foundations when proposing oscillator/ rotator method installation.

DRAFT Appendix C-26 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
19 The CIDH piles are designed to obtain their geotechnical capacity through side resistance.

Nonetheless, the bottom of drilled holes must be cleaned in accordance with Section 49-

3.02C(2), “Drilled Holes,” of Caltrans 2018 Standard Specifications. Prior to approval, the Engineer must verify the bottom of the drilled holes are cleaned before placement of the concrete.

Excavation of the CIDH piles, placement of the rebar cage, and concrete pour should be completed in one continuous operation.

Prior to mobilization to the site, the foundation contractor should prepare a Pile Installation Plan in accordance with Section 49-3.02A(3)(b) of the Caltrans Standard Specifications. The drilled shaft installation plane to be submitted by the contractor should include a description of the tools and equipment planned to be used by the contractor for CIDH pile installation. The actual tools and equipment used during CIDH pile excavation/installation should be documented in the construction records. If oscillator/rotator method is used, the contractor’s workplan should include/outline measures to extract a seized casing without compromising the integrity of the CIDH excavation.

9.2 LATERAL EARTH PRESSURES
We present equivalent fluid weights (EFWs) in the table below for the buried structures and bridge abutments. These values assume fully drained and level backfill conditions.

Table 13: Recommended Equivalent Fluid Weight (EFW)
Condition
Static Incremental Seismic
Coefficient k
(dim.) EFW (pcf) Coefficient Dk
(dim.) DEFWEQ (pcf)
Active 0.28 34 0.22 27
At-Rest 0.44 53 NA 43
The EFW values shown above assume:
• Level backfill condition;
• Structure Backfill with soil unit weight (g) = 120 pcf and minimum angle of internal friction (f) = 34°. This is considered to be achievable from the native silty sands; • Horizontal seismic acceleration coefficient (kh) ≤ 0.2; and • Vertical seismic acceleration coefficient (kv) = 0.0.

The passive fluid weight is only applicable if the retained earth is allowed to strain at least

0.02H.

For static design, apply the resultant of the static earth pressure at a depth of 0.33H from the base of the wall where H equals the wall height. At-rest and Active earth pressures do not DRAFT Appendix C-27 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
20 include a factor of safety. Use a static passive earth pressure of 210 pcf which has been reduced by a factor of safety of 2.0 and a coefficient of friction of 0.70 for lateral restraint.

For seismic design, calculate the resultant of incremental/additional lateral soil pressure due to seismic loading based on the equivalent fluid weights above and apply the magnitude of the resultant at 0.66H from the base of the wall where H equals the wall height. Add the resultant of the seismic earth pressure to the resultant of the static active or “at-rest” earth pressure.

Reduce the static passive pressure to 170 pcf for a seismic event.

For permanent surcharge loads, apply a uniform load to the wall equal to 0.45-times the surcharge load. Apply an additional 200 psf to accommodate transient and construction surcharge loading (comparable with AASHTO H-20).

9.3 GRADING

9.3.1 CLEARING
Prior to grading, demolish and clear the site to remove structures, fences, vegetation, tree roots, debris, abandoned utilities, soft or unstable areas, and other deleterious materials.

9.3.2 SUBGRADE
Scarify and compact the upper 10 inches of soil in areas to receive fill (outside of the tank pad) to at least 90 percent relative compaction with at least optimum moisture content per ASTM D1557. The excavation bottom must be firm and unyielding prior to placing concrete.

Place fill in maximum 8-inch-thick loose lifts, moisture condition to within 2% of optimum moisture content and compact to a minimum 90% relative compaction per ASTM D1557.

Increase the relative compaction to 95% in the upper 6-inches beneath the pavement areas.

Native materials, minus organics, debris, and other deleterious materials, are suitable for engineered fill with a maximum particle size of 4 inches. Excavated materials unsuitable for use as structural fill should be placed outside the structure limits.

9.3.3 OVEREXCAVATION – TANK PAD
To reduce the amount of settlement to within the required tolerances provided by DN Tanks, the near surface soils are recommended to be removed, processed and recompacted below the planned tank. Our analysis shows that an overexcavation to a depth of 5 feet below existing grade (to an elevation of approximately 592 feet) is recommended. In addition to the area below the tank, extend the overexcavation to a minimum of 5 feet laterally beyond the tank and foundation footprint in all directions.

Scarify the exposed subgrade to a depth of 10 inches and compact to at least 95% percent relative compaction with at least optimum moisture content per ASTM D1557. The excavation bottom is recommended to be firm and unyielding prior to placing concrete. Place and compact fill per Section 9.2.5 below.

DRAFT Appendix C-28 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
21 9.3.4 OVER-OPTIMUM SOIL MOISTURE
Excessively over-optimum (wet) soil conditions can make proper compaction difficult or impossible.

In general, wet soil can be mitigated by:
• Discing the soil during prolonged periods of dry weather, • Over-excavating and replacing with drier material,
• Stabilization using aggregate and stabilization fabric or grid.

Crawford should be consulted for further recommendations if these conditions are encountered during grading.

9.3.5 BACKFILL
Native silty sands or select import can be used as backfill. Moisture condition backfill to within 2 percent of optimum and place in maximum 8-inch thick, horizontal, loose lifts. Compact backfill to a minimum 95 percent relative compaction based on the ASTM D 1557 test procedure.

In order to minimize the residual lateral earth pressures on structure walls, compaction equipment used behind the walls must be restricted (by load and distance from wall) so that wall design values are not exceeded. For this reason, we recommend compaction within a horizontal distance equal to one-half of the wall height, up to a distance of 5 feet, to be completed with hand-operated equipment (i.e., jumping jack). To minimize the potential for significant settlement around deep walls, controlled low strength material (CLSM) can be used to backfill to the surface or to a manageable depth (e.g. 5 to 10 feet below grade).

9.3.6 IMPORT MATERIAL
Import fill shall be granular soil, free of organic material and debris, have an Expansion Index (per ASTM D4829) of less than 25, an R-value greater than XX, and conform to the following gradation:

Sieve Size Percentage Passing
2-inch 100
No. 4 35 – 100
No. 30 20 – 100
No. 200 10 – 45
Caltrans Class 2 aggregate base is considered acceptable and does not need to meet these gradation requirements. Import fill must be observed and tested by Crawford prior to its approval.

9.4 OPEN-CUT PIPELINE RECOMMENDATIONS
Generally, the open-cut portions of the pipeline will have a minimum of 4 feet of cover along the all the segments of the pipeline.

DRAFT Appendix C-29 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
22 9.4.1 SOIL LOADS ON RIGID BURIED PIPES
Due to the lack of ductility of rigid pipelines, the dead loads and associated strain are important to analyze. The soil deadload (WD) on the rigid pipeline in a trench may be evaluated by Marston’s Formula:

𝑊! = 𝐶"𝛾𝐵"
#
Where:

𝐶" = load coefficient based on 𝐾$
%
𝛾 = moist unit weight of backfill material (pcf)
𝐵" = width of trench at top of pipe (ft)
Use a moist unit weight of 135 pcf for the above calculation.

Similar to Composite Modulus of Soil Reaction, the backfill material and compaction, trench width, and installation depth are components to designing the pipeline. For an open cut installation with a ratio of the backfill depth to trench width at the top of the pipe (𝐻/𝐵") of at least 1 (i.e. backfill depth is greater than the trench width) and for a trench width at top of pipe no greater than 3 times the pipe diameter, Cd
12 may be calculated by:

𝐶" = 1 − 𝑒&#'$!(
)
2𝐾𝜇%
Where:

𝐾 = rankine’s lateral earth pressure coefficient
𝜇% = friction coefficient between fill material and sides of trench 𝐻 = backfill height above the pipe crown (feet)
The combined 𝐾𝜇% value is dependent on backfill type, compaction, and moisture content. Using the backfill recommendations in this report, the estimated 𝐾𝜇% values are 0.120 for clay, 0.130 for silt, and 0.150 for sands and aggregate base.

9.4.2 SOIL LOADS ON FLEXIBLE BURIED PIPES
Soil loads on flexible buried pipes should be analyzed as well. Based on AWWA M11, if the flexible pipe is buried in a trench less than two times the width of the pipe, the load is computed as:

𝑊* = 𝐶"𝛾𝐵"
#(
𝐵*
𝐵"
)
Where:

𝑊* = dead load on the conduit (lb/lin ft)
𝐶" = load coefficient based on 𝐾$
% (presented in Section 9.4.1)
𝛾 = moist unit weight of backfill material (pcf)
𝐵" = width of trench at top of pipe (ft)
12 American Concrete Pipe Association (2000)
DRAFT Appendix C-30 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
23 𝐵* = diameter of pipe (ft)
If the flexible pipe is installed with trenchless techniques or a wide trench (i.e. trench width is greater than two times the width of the pipe):

𝑊* = 𝛾𝐻𝐵*
Where:

𝑊* = dead load on the conduit (lb/lin ft)
𝛾 = moist unit weight of backfill material (pcf)
𝐻 = height of fill above top of pipe (ft)
𝐵* = diameter of pipe (ft)

9.4.3 THRUST RESTRAINT
Unbalanced thrust forces develop in a pipeline due to internal pressures, particularly around change of direction in the pipeline alignment. For large diameter pipelines, these thrust forces are typically counteracted by frictional resistance along the pipe and restrained joints.

Restrained joints resist thrust forces through friction between the pipe and the soil surrounding it. Per AWWA M11, the length of pipeline required to restrain each side of an alignment bend is:

𝐿 = 𝑃𝐴(𝑐𝑜𝑠∆)
𝜇(𝑊+ + 𝑊, + 𝑊-)
Where:

𝐿 = length of restrained or harnessed joints on each side of the bend or elbow (ft) 𝑃 = internal pressure (psi)
𝐴 = cross-sectional area of the pipe (in2)
∆ = bend or elbow deflection (degrees), 0° to 90°
𝜇 = coefficient of friction between the pipe and the soil 𝑊+ = horizontal bends: two times the weight of the prism of soil over the pipe (lb/ft of pipe length)
= vertical bends: weight of the prism of soil over the pipe (lb/ft of pipe length) 𝑊- = weight of the pipe (lb/ft)
𝑊, = weight of the contained water (lb/ft)
The coefficient of friction between a steel pipe and the surrounding soil is modeled as: 𝜇 = 𝑡𝑎𝑛 (0.6𝜙), where 𝜙 is the soil friction angle. Assuming a soil friction angle of 36° for compacted coarse grained, angular backfill soil, we recommend using a coefficient of friction of 0.40.

Although likely unnecessary for the majority of this project, thrust blocks may also be used if additional thrust resistance is needed. Thrust block design is governed by two factors – the total thrust force and the allowable passive pressure of the soil. Allowable passive pressure will be variable throughout the alignment due to varying soil conditions. We calculated passive pressures at each of our boring locations to assess trending values along the alignment. Based on this trend, we recommend a passive pressure of 205 pcf for borings classified with clayey and 250 pcf for the borings classified with sandy materials for thrust block design; see the table DRAFT Appendix C-31 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
24 below for the recommended passive pressures associated with each boring. The upper 12 inches of soils should be ignored.

Table 14: Recommended Passive Pressure Values
Boring
Number
Approximate
Station1
Recommended Passive
Pressure (pcf)
A-19-003 A20+74.8 Lt 50.8 205
A-19-005 A45+45.1 Lt 15.5 250
A-19-006 A54+40.8 Lt 53.0 205
A-19-007 A67+16.5 Lt 15.3 250
A-19-008 A74+10.6 Lt 12.0 205
A-19-010 A88+46.8 Rt 15.7 250
A-19-011 B24+50.3 Rt 15.4 205
A-19-012 B15+29.6 Rt 19.7 250
A-19-013 C15+62.3 Lt 17.8 205
A-19-014 C25+10 Rt 76.7 250
A-19-015 C36+08.6 Rt 56.8 205
A-19-016 C44+24.5 Lt 70.3 250
A-19-018 C58+94.6 Lt 10.4 205
A-19-019 C62+97.8 Lt 44.4 205
A-19-020 D16+34.8 Lt 10.3 250
A-19-022 C51+31.3 Lt 50.1 205
A-19-023 E22+29.7 Lt 12.3 250
1Stations correlate with Figure 2 attached.

9.4.4 COMPOSITE MODULUS OF SOIL REACTION
Semi-rigid and flexible pipes are designed to withstand a certain amount of deflection from applied earth loads. One of the input parameters to pipe deflection equations is the Composite Modulus of Soil Reaction (CMSR). The CMSR value is influenced by native soil properties, backfill soil properties, and trench/pipe geometry. We calculated composite modulus of soil reaction values using the Howard (2011) and AWWA M11 and M45 method. This approach multiplies the modulus of soil reaction for the embedment soil (i.e. trench backfill) by a soil support combining factor, S. Using the above parameters, we selected our S values from Table 1 of “Amster Howard, TECH NOTE, A supplement to Pipeline Installation,” dated October 3, 2011. For these calculations, we assume the trench specifications provided by Carollo Engineers in the June 2019 plans page TP01. We provide a brief summary of the specifications below:
• Trench Geometry
• For pipe diameters, less than 24-inches, the trench width will be between 18 and 24- inches greater than the pipe diameter. We calculated the CMSR using a minimum trench width equal to 18-inches wider (9-inches per side) than the pipe diameter.

DRAFT Appendix C-32 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
25 • Backfill Material
• Sand or aggregate base course
• Compaction
• Pipe bedding will have a relative compaction (per ASTM D1557) greater than or equal to 90%
• Trench backfill will have a relative compaction (per ASTM D1557) greater than or equal to 95%
Below is the pipe trench profile geometry as provided by Carollo.

Using these assumptions, pipe depth, size, installation type, and the geotechnical information presented herein, we calculated Composite Modulus of Soil Reaction values at each exploration location. We present our CMSR values in Table 15.

Table 15: Composite Modulus of Soil Reaction Values
Boring
Number
Pipe Outer
Diameter (in)
Approximate
Station1
CMSR
(psi)
R-19-001 18 A10+95.2 Rt 21.9 4,000
R-19-002 18 A13+98.8 Rt 35.8 4,000
DRAFT Appendix C-33 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
26 Boring
Number
Pipe Outer
Diameter (in)
Approximate
Station1
CMSR
(psi)
A-19-003 18 A20+74.8 Lt 50.8 2,000
R-19-004 18 A34+37.6 Lt 1.3 4,000
A-19-005 18 A45+45.1 Lt 15.5 1,700
A-19-006 18 A54+40.8 Lt 53.0 1,450
A-19-007 10 A67+16.5 Lt 15.3 2,000
A-19-008 10 A74+10.6 Lt 12.0 1,950
A-19-010 10 A88+46.8 Rt 15.7 1,650
A-19-011 4 B24+50.3 Rt 15.4 1,600
A-19-012 4 B15+29.6 Rt 19.7 1,600
A-19-013 12 C15+62.3 Lt 17.8 2,100
A-19-014 12 C25+10 Rt 76.7 1,700
A-19-015 6 C36+08.6 Rt 56.8 1,550
A-19-016 6 C44+24.5 Lt 70.3 1,650
A-19-018 4 C58+94.6 Lt 10.4 1,600
A-19-019 4 C62+97.8 Lt 44.4 1,600
A-19-020 4 D16+34.8 Lt 10.3 1,600
A-19-022 6 C51+31.3 Lt 50.1 1,600
A-19-023 10 E22+29.7 Lt 12.3 1,900
R-19-024 18 A32+87.8 Lt 34.4 4,000
1 Stations correlate with Figure 2 attached.

To calculate the above results, we assumed a sand backfill and applied an Eb’ (trench backfill Modulus of Soil Reaction) value of 1,600 psi. Native Moduli of Soil Reaction varied from 800 in loose clayey sands to 5,000 in hard clays and dense gravels with silt. Final design values should be calculated based on actual backfill Modulus of Soil Reaction and trench/pipe dimensions.

9.5 TRENCHLESS PIPELINE RECOMMENDATIONS
There are two locations along the alignment where trenchless technology will be used to install the 18-inch OD pipeline where traditional open-cut trenching methods are not feasible. Many trenchless technologies are feasible for construction at these locations. The contractor is responsible for selecting appropriate trenchless installation methods. The chosen trenchless method should not cause differential settlement, surface soil heaving, or damage to existing facilities and utilities. The method and approach must maintain pipeline vertical and horizontal alignment within design tolerances.

Crawford completed four explorations at the following trenchless crossing locations:
• Trenchless Crossing 1 at Highway 101 (Borings R-19-001 and R-19-002) • Trenchless Crossing 2 at Bush Street (Borings R-19-004 and R-19-024) DRAFT Appendix C-34 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
27 Trenchless crossing locations are presented on Figure 2.

At each trenchless crossing, launching and receiving shafts (pits) will need to be excavated to house the trenchless installation equipment if direct access trenchless methods (e.g., horizontal auger bore, jack-and-bore, micro tunneling, etc.) are used instead of Horizontal Direction Drilling (HDD). Although the contractor would likely have launching and receiving pits for HDD to control hydraulic fracture of the drilling mud, the pits would be less significant and likely not require shoring. With the advantage of less expensive pits, HDD comes with the disadvantage of needing substantial staging area to lay out the pipe prior to installation.

9.5.1 SHAFTS
Shoring should be designed to prevent material from entering the shaft during all construction operations. Dewatering will likely be necessary during excavation of the launching and receiving shafts.

Based on our understanding of the project, the bottom of pipe elevation at Trenchless Crossing 1 will be about 592 feet. The bottom of pipe elevation at Trenchless Crossings 2 will be about 598 feet. We assume entry and receiving pit bottoms will be at elevation 590 feet at Trenchless Crossing 1 and 596 feet at Trenchless Crossing 2 to provide space for the installation equipment.

We provide the following bearing capacities and shallowest groundwater condition we anticipate at each crossing. The shallowest groundwater level was encountered in boring R-19-004 during our March 21, 2019 field exploration. We estimate approximately 1 inch of immediate and less than ¾ inches of differential settlement. The following bearing capacities are for the support of drilling/driving equipment at the base of the pit.

Table 16: Trenchless Locations Bearing Capacity
Trenchless Location Allowable Bearing Capacity, psf Static Groundwater Elevation, ft Crossing 1 2,500 600
Crossing 2 2,000 600
With proper shoring in place, the base of the shafts should be reviewed to see if the in-situ soil is suitable for the stability of the trenchless installation equipment. If the soil is found to be unstable, (excavate one foot of in-situ soil) place a 12” layer of aggregate base course compacted to at least 85% relative compaction on top of a nonwoven geotextile fabric layer (Mirafi S1000 or similar product).

We present the following passive pressure for the walls of the trenchless shafts assuming fully drained conditions.

DRAFT Appendix C-35 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
28 Table 17: Trenchless Passive Pressures
Trenchless Crossing 1
Passive Pressure 195 psf
Trenchless Crossing 2
Passive Pressure 200 psf
Once the trenchless portion of the pipe is installed, the launching and receiving shafts must be backfilled per Mendocino County or City of Ukiah requirements.

9.6 PAVEMENT
We completed two R-Value tests (CTM 301) on bulk samples of near surface soil. Test results indicate R-values of 21 to 35 by stabilometer. Therefore, we recommend using R-Value 21 for project pavement design.

Using varying Traffic Indices and Chapter 600 of the Caltrans Highway Design Manual (CHDM), 6th Edition, we recommend the sections shown in Table 18 below for pavement design.

Table 18: Pavement Sections
Traffic Index
Pavement Sections
R-Value 21
Hot Mix Asphalt (ft) Aggregate Base (ft)

5.0 0.20 0.70

5.5 0.25 0.75

6.0 0.25 0.90

6.5 0.30 0.90

7.0 0.30 1.05

7.5 0.35 1.10

8.0 0.40 1.15

8.5 0.40 1.25

9.0 0.45 1.30
*The upper 0.2 feet of HMA may be replaced with rubberized hot mix asphalt.

Design by the Caltrans method presumes materials and construction in accordance with Caltrans “Standard Specifications”, including 95% relative compaction on all materials within 30-inches of finished grade. Inability to achieve the required compaction on the scarified materials may be used as a field criterion to identify areas requiring additional removal and/or re-compaction.

DRAFT Appendix C-36 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
29 The subgrade soils should be field reviewed with respect to uniformity and suitability by the soils engineer. Any loose, disturbed or otherwise unsuitable materials should be removed to full depth and replaced with imported fill meeting the requirements of the Standard Specifications or Class 2 Aggregate Base compacted to at least 90% relative compaction.

The above pavement design assumes that free water will be absent from the structural section.

Suitable surface drainage is of particular importance to limit subgrade saturation and excess free water.

9.7 CONSTRUCTION CONSIDERATIONS

9.7.1 DEWATERING
Based on our observed groundwater levels in Spring 2019, we encountered groundwater within trench excavation limits in boring A-19-020 as well as at the Trenchless Crossing location in boring R-19-004. Groundwater will adversely affect construction of portions of the pipeline and trenchless crossings located near these borings. In addition, we encountered groundwater at an approximate elevation of 575 feet in R-19-009, potentially impacting the pump station and tank constructions. Isolated areas of groundwater seepage are likely to be encountered along other portions of the alignment.

The contractor will be responsible for designing and implementing a dewatering system to meet the requirements of the project. Dewatering operations will need to draw down the groundwater down to a minimum of 3 feet below the planned excavation during construction. Dewatering operations may enter into layers of clean sands that may yield significant water.

9.7.2 EXCAVATABILITY
Based on the conditions observed in our subsurface explorations and our experience, the onsite soil should be excavatable with typical equipment such as backhoes and excavators.

Depending on county easement dimensions and pavement configurations, the contractor may need to shore the existing roadway to accommodate traffic if there is insufficient room to properly slope the trench excavation.

9.7.3 SHORING AND TEMPORARY CONSTRUCTION SLOPES
At a minimum, all shoring and temporary construction slopes should be in accordance with current OSHA requirements. Our data indicates Cal OSHA Soil Type C will be encountered throughout the project alignment with the exception of the stiff fine-grained soil layers we encountered. Isolated locations of unstable soils can be encountered, particularly where the trench is adjacent to existing utilities or other improvements. Traffic and construction vibrations need to be considered in shoring applications.

The contractor is responsible for all shoring and temporary slope design based on actual excavation conditions encountered during construction. Shoring will need to be conducive to the contractor’s approach to managing groundwater (where needed) and the excavation.

DRAFT Appendix C-37 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021
30 10 LIMITATIONS
Crawford performed services in accordance with generally accepted geotechnical engineering principles and practices currently used in this area. Do not use this report for different locations and/or projects without the written consent of Crawford. Where referenced, we used ASTM or Caltrans standards as a general (not strict) guideline only.

Crawford based this report on the current site conditions. We assumed the soil and groundwater conditions are representative of the subsurface conditions on the site. Actual conditions between explorations will vary along the project alignment.

Our scope did not include evaluation of on-site hazardous materials.

Logs of our explorations are presented as Appendix II. The lines designating the interface between soil types are approximate. The transition between soil types may be abrupt or gradual. Our recommendations are based on the final logs, which represent our interpretation of the field logs and general knowledge of the site and geological conditions DRAFT Appendix C-38 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021

APPENDIX I - FIGURES
Figure 1: Vicinity Map
Figure 2: Exploration Location Map
Figure 3: Geologic Map
Figure 4: Fault Activity Map
DRAFT Appendix C-39 8660F10 April 2023

Appendix C-40 8660F10 April 2023

Project
Alignment
Figure 1
Vicinity Map
North 1"=3,000'
Proj. No: 19-503.1
Scale:

Date:

City of Ukiah Recycled
Water Pipeline
Ukiah, California
7/9/19
Source: USGS 7.5' Topographic Maps, Ukiah,
Mendocino County, California, 2018, Scale: 1:24,000
DRAFT Appendix C-41 8660F10 April 2023

A10+00 A10+00 A50+00 A42+00 A34+00 A26+00 A18+00 A58+00 A66+00
A74+00 A82+00 A90+00 R-19-002 R-19-001 A-19-003 A-19-005 R-19-004 A-19-006 A-19-007 A-19-008 A-19-009 A-19-010 A-19-011 A-19-012 A-19-013 A-19-015 A-19-014 A-19-016 R-19-017 A-19-018 A-19-019 A-19-023 R-19-024 A-19-022 A-19-020 R-19-021 B12+00 B20+00 C12+00 C18+00 C26+00 C34+00 C42+00 C50+00 C58+00 C66+00 D12+00 E12+00
E18+00A-20-001 R-20-002 R-20-003 BORING LOCATIONS LEGEND R-19-001 Figure 2 Site Map North 1"=1,000' Proj. No: 19-503.1 Scale: Date: City of Ukiah Recycled Water Pipeline Ukiah, California 12/14/19 PROJECT ALIGNMENT A10+00 DRAFT
Appendix C-42 8660F10 April 2023

Proj. No: 19-503.1 Scale: Date: City of Ukiah Recycled Water Pipeline Ukiah, California Qal Alluvium Qt Quaternary nonmarine terrace deposits QP Plio-Pleistocene nonmarine K Undivided Cretaceous marine KJf Franciscan Formation KJfv Franciscan volcanic and metavolcanic rocks ub Mesozoic ultrabasic intrusive rocks Fault (Dashed where approximately located) Project Location Figure 3 Geologic Map 1"=10,000' Source: Jennings, C.W., and Strand, R.G.. Geologic map of California : Ukiah sheet. Scale: 1:250,000. California: California Division of Mines and Geology, 1960. North 12/14/20 K K KJf KJf KJf QP QP QPQP QP QP Qt Qt Qt QtQt Qt Qt Qt Qal Qal ub ub ub KJfv KJfv KJfv Qt DRAFT
Appendix C-43 8660F10 April 2023

Proj. No: 19-503.1 Scale: Date: City of Ukiah Recycled Water Pipeline Ukiah, California LEGEND Quaternary Fault (Age) <150 years <15,000 years <130,000 years Quaternary Fault (Age) <1.6 million years Location Well Constrained Moderately Constrained Inferred Figure 4 Fault Activity Map Source: Basemap: AutoCAD Civil3D Geolocation Tool, using Bing Maps Fault Data: USGS GIS Data Project Location North 1"=30,000' Maacama fault zone San Andreas fault zone West Margin fault Bartlett Springs fault system
Clover Valley fault zone Konocti Bay fault zone 12/14/20 DRAFT
Appendix C-44 8660F10 April 2023

DRAFT GEOTECHNICAL REPORT Crawford
City of Ukiah Recycled Water Pipeline – Phase 4 Design Project File: 19-503.1 Ukiah, California August 20, 2021

APPENDIX II
Boring Log Legend
Boring Logs
DRAFT Appendix C-45 8660F10 April 2023

Appendix C-46 8660F10 April 2023

C Consolidation
CL Collapse Potential
CP Compaction Curve
CR Corrosion, Sulfates, Chlorides
CU Consolidated Undrained Triaxial
DR Drained Residual Shear Strength
DS Direct Shear
EI Expansion Index
M Moisture Content
OC Organic Content
P Permeability
PA Particle Size Analysis
PI Liquid Limit, Plastic Limit, Plasticity Index
PL Point Load Index
PM Pressure Meter
PP Pocket Penetrometer
R R-Value
SE Sand Equivalent
SG Specific Gravity
SW Swell Potential
TV Pocket Torvane
UC Unconfined Compression - Soil
Unconfined Compression - Rock
UU Unconsolidated Undrained Triaxial
UW Unit Weight
DRAFT Appendix C-47 8660F10 April 2023

DRAFT Appendix C-48 8660F10 April 2023

Lean CLAY (CL); very stiff; brown; moist; few SAND;
mostly medium plasticity, very high dry strength, low
toughness fines.

About 14% SAND; mostly medium plasticity fines.

Stiff.

Very stiff; trace fine GRAVEL.

Little fine SAND.

Stiff.

Some medium to fine SAND.

Very stiff.

Some SAND.

Poorly graded GRAVEL with CLAY and SAND
(GP-GC); very dense; brown; moist; mostly coarse to
fine GRAVEL; little medium SAND; few low to
medium plasticity fines.

Trace low to medium plasticity fines.
17 Unconfined Compressive
Strength
Unconfined = 5,069 psf
Proposed trenchless
crossing pipe invert
depth.

Unconfined Compressive
Strength
Unconfined = 6,840 psf
Switched to end discharge
(94mm) mud rotary.

Drill Chatter
5 10
10 5
7 8
8 15
15 6
9 13
12 19
21 5
6 8
9 12
12 4
9 5
7 24
50/5
24 50/5
22 50
20 15
30 22
40 14
24 14
74/11
50/5

2.50 1.50

3.50 3.50

2.75 2.00

1.50 2.00
30 19.5
18 17.9

20.4 19.8

22.7 22

97.9 109.7
111.9
108.7
106.6
107
107
LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: AC
DRILLING METHOD: Solid-Stem Auger & Rotary Wash
DRILL RIG: CME 75 Track
SAMPLER TYPE & SIZE: Bulk; CAL (2.4" ID); SPT (1.4" ID) BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 50.5 (ft) BACKFILL METHOD: Tremie Grout LOG OF BORING R-19-001

LABORATORY
CLIENT: Carollo Engineers
BEGIN DATE: 3/14/2019
COMPLETION DATE: 3/14/2019
SURFACE ELEVATION: 608 (ft)*
SURFACE CONDITION: Soil
WATER DEPTH: Not Established
READING TAKEN: N/A
HAMMER EFFICIENCY: 70 (%)
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 605
600
595
590
585
580
575
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 2
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: R-19-001
ENTRY BY: AC
CHECKED BY: KKL
Bulk
1 1
2 3
4 5
6 7
8 9
10 11
100
56 83
67 94
67 100
83 33
100
100
100
0 5
10 15
20 25
30 35
86 DRAFT Appendix C-49 8660F10 April 2023

Poorly graded GRAVEL with CLAY and SAND
(GP-GC) (continued).

Some medium to fine SAND; little low to medium
plasticity fines.

Bottom of borehole at 50.5 ft bgs
Groundwater not established due to drilling method.
30 35
31 44
50/4
50 66
50/4

FIELD LABORATORY

SAMPLECASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 570
565
560
555
550
545
540
535
530
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 2 of 2
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: R-19-001
ENTRY BY: AC
CHECKED BY: KKL
12 13
14 67
80 67
40 45
50 55
60 65
70 75
80 DRAFT Appendix C-50 8660F10 April 2023

Lean CLAY (CL); stiff; brown; moist; few medium to
fine SAND; mostly medium plasticity fines.

About 7% medium to fine SAND.

Very stiff; about 28% coarse to fine SAND; mostly
medium plasticity fines.

Few fine GRAVEL.

Stiff; mottled gray.

Soft to medium stiff; gray.

CLAYEY SAND (SC); medium dense; gray; wet;
mostly medium SAND; little nonplastic to low
plasticity fines.

Poorly graded GRAVEL with CLAY (GP-GC); very
dense; gray; moist; mostly fine GRAVEL; some
medium SAND; little nonplastic to low plasticity fines.

Unconfined Compressive
Strength
Unconfined = 2,016 psf
Proposed trenchless
crossing pipe invert depth.

Corrosion
pH = 6.14
Min. Resist. = 2,650 ohmcm
Chlorides = 1.5 ppm
Sulfates = 5.7 ppm
Switched to end discharge
(94mm) mud rotary.

Drill Chatter
3 5
6 5
7 12
PUSH
9 16
7 11
12 4
4 7
PUSH
2 20
27 46
40 11
19 25
23 11
22 86

1.50 3.00

3.00 1.00

0.50 25.2

18.6 25.9

23.4 24.1

98.1 111

98.5 105.4

98.1 LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: AC
DRILLING METHOD: Solid-Stem Auger & Rotary
DRILL RIG: CME 55 Truck
SAMPLER TYPE & SIZE: CAL (2.4" ID)
BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 41.5 (ft) BACKFILL METHOD: Tremie Grout LOG OF BORING R-19-002

LABORATORY
CLIENT: Carollo Engineers
BEGIN DATE: 3/22/2019
COMPLETION DATE: 3/22/2019
SURFACE ELEVATION: 603.2 (ft)*
SURFACE CONDITION: Soil
WATER DEPTH: Not Established
READING TAKEN: N/A
HAMMER EFFICIENCY: 77 (%)
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 600
595
590
585
580
575
570
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 2
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: R-19-002
ENTRY BY: AC
CHECKED BY: KKL
1 2
3 4
5 6
7 67
100
100
72 100
67 67
0 5
10 15
20 25
30 35
93 72
DRAFT Appendix C-51 8660F10 April 2023

Poorly graded GRAVEL with CLAY (GP-GC)
(continued). CLAYEY GRAVEL (GC); very dense; moist; mostly fine GRAVEL; little medium SAND; some low
plasticity fines.

Bottom of borehole at 41.5 ft bgs
Groundwater not established due to drilling method.
30 32
35 67

FIELD LABORATORY

SAMPLECASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 565
560
555
550
545
540
535
530
525
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 2 of 2
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: R-19-002
ENTRY BY: AC
CHECKED BY: KKL
8 83 40
45 50
55 60
65 70
75 80
DRAFT Appendix C-52 8660F10 April 2023

Lean CLAY (CL); stiff; brown; moist; mostly medium
plasticity, medium toughness fines.

Very stiff.

Few fine SAND; mottled orange brown and gray.

CLAYEY SAND (SC); medium dense; gray; moist;
little coarse to fine, subrounded GRAVEL; mostly
coarse to fine SAND; some medium plasticity fines.

Little medium plasticity fines.

Bottom of borehole at 21.3 ft bgs
Unconfined Compressive
Strength
Unconfined = 2,477 psf
4 7
10 4
4 7
5 10
14 4
7 9
8 15
31 36
41 50/4
17 11
24 16
46 91/10

1.75 2.00

2.50 2.00

3.75 32.1

25.4 25
89 104.4
101
LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: HFW
DRILLING METHOD: Solid-Stem Auger
DRILL RIG: CME 75 Track
SAMPLER TYPE & SIZE: CAL (2.4" ID)
BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 21.3 (ft) BACKFILL METHOD: Free Fall
LOG OF BORING A-19-003

LABORATORY
CLIENT: Carollo Engineers
BEGIN DATE: 3/20/2019
COMPLETION DATE: 3/20/2019
SURFACE ELEVATION: 605 (ft)*
SURFACE CONDITION: Soil
WATER DEPTH: Not Encountered
READING TAKEN: N/A
HAMMER EFFICIENCY: 70 (%)
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 600
595
590
585
580
575
570
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 1
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: A-19-003
ENTRY BY: AC
CHECKED BY: KKL
1 2
3 4
5 6
100
100
67 100
50 38
0 5
10 15
20 25
30 35
DRAFT Appendix C-53 8660F10 April 2023

ASPHALT.

Aggregate Base (AB).

SANDY lean CLAY (CL); soft; brown; moist; trace
GRAVEL; few fine SAND; mostly medium plasticity,
low to medium toughness fines.

About 3% fine GRAVEL; about 44% coarse to fine
SAND; mostly medium plasticity fines.

SANDY lean CLAY (CL); gray; some medium to fine
SAND.

Lean CLAY with SAND (CL); very stiff to hard; little
fine SAND; mostly medium to high plasticity, medium
toughness fines.

Poorly graded GRAVEL with SAND (GP); very dense;
light reddish brown; moist; mostly coarse to fine
GRAVEL; some medium SAND; few medium
plasticity fines.

Poorly graded SAND with GRAVEL (SP); very dense;
brown; moist; some fine GRAVEL; mostly coarse to
medium SAND; few fines.

Poorly graded GRAVEL with SAND (GP); very dense;
gray; moist; mostly coarse to fine GRAVEL; some
medium SAND; few fines.

Dense.
14 AC = 5"
AB = 6"
Corrosion
pH = 6.89
Min. Resist. = 3,480
ohm-cm
Chlorides = 1.4 ppm
Sulfates = 15.0 ppm
Unconfined Compressive
Strength
Unconfined = 749 psf
Switched to end discharge
(94mm) mud rotary.

Drill Chatter
Driller Note: Drilling
material became very soft.
3 3
8 PUSH
4 4
6 13
20 24
28 44
15 40
44 10
20 50/4
7 11
26 11
8 33
72 84
70/10
37 0.50

0.50 +4.50
25 23.5

19.9 22.8

23.5 106.9
101.7
103.8
106.9
LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: AC
DRILLING METHOD: Solid-Stem Auger & Rotary
DRILL RIG: CME 55 Truck
SAMPLER TYPE & SIZE: Bulk; CAL (2.4" ID)
BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 51.5 (ft) BACKFILL METHOD: Tremie Grout BEGIN DATE: 3/21/2019
COMPLETION DATE: 3/21/2019
SURFACE ELEVATION: 613.0 (ft)*
SURFACE CONDITION: Asphalt
HAMMER EFFICIENCY: 77 (%)
LOG OF BORING R-19-004

LABORATORY
CLIENT: Carollo Engineers WATER DEPTH: 7.6(ft.)
READING TAKEN: 3/21/19
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 610
605
600
595
590
585
580
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 2
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: R-19-004
ENTRY BY: AC
CHECKED BY: KKL
Bulk
1 1
2 3
4 5
6 7
100
83 100
72 78
89 100
0 0
5 10
15 20
25 30
35 53
DRAFT Appendix C-54 8660F10 April 2023

Poorly graded GRAVEL with SAND (GP) (continued). Poorly graded GRAVEL with CLAY (GP-GC); dense; gray; moist; mostly coarse to fine GRAVEL; little low
to medium plasticity fines.

Lean CLAY (CL); very stiff; brown; moist; trace
medium to fine SAND; mostly medium plasticity,
medium toughness fines; varigated gray.

CLAYEY SAND (SC); dense; gray; moist; trace fine
GRAVEL; mostly medium SAND; little low to
medium plasticity fines.

Lean CLAY (CL); very stiff; gray; moist; trace fine
SAND; mostly medium plasticity, medium toughness
fines.

Bottom of borehole at 51.5 ft bgs
11 22
13 11
16 21
10 16
24 35
37 40

3.00 3.00

FIELD LABORATORY

SAMPLECASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 575
570
565
560
555
550
545
540
535
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 2 of 2
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: R-19-004
ENTRY BY: AC
CHECKED BY: KKL
8 9
10 67
50 67
40 45
50 55
60 65
70 75
80 DRAFT Appendix C-55 8660F10 April 2023

ASPHALT.

Aggregate Base (AB).

CLAYEY SAND (SC); medium dense; brown; moist;
mostly medium to fine SAND; little low to medium
plasticity fines; weak cementation.

Very dense.

Dense.

Very dense; moderate cementation.

Poorly graded SAND with CLAY and GRAVEL
(SP-SC); dense; brown; moist; little coarse to fine
GRAVEL; mostly medium SAND; little low to
medium plasticity fines.

Lean CLAY (CL); medium stiff; brown; moist; mostly
medium plasticity, medium toughness fines.

Bottom of borehole at 21.6 ft bgs
AC = 3"
AB = 3"
Soil classification at
bottom of boring classified
via shoe of sampler.
14 19
15 13
28 26
20 18
16 21
29 28
14 16
23 34
54 34
57 39

10.7 11.3
119.8
128.7
LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: AC
DRILLING METHOD: Solid-Stem Auger
DRILL RIG: CME 55 Truck
SAMPLER TYPE & SIZE: CAL (2.4" ID)
BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 21.6 (ft) BACKFILL METHOD: Free Fall
LOG OF BORING A-19-005

LABORATORY
CLIENT: Carollo Engineers
BEGIN DATE: 3/21/2019
COMPLETION DATE: 3/21/2019
SURFACE ELEVATION: 638.5 (ft)*
SURFACE CONDITION: Asphalt
WATER DEPTH: Not Encountered
READING TAKEN: N/A
HAMMER EFFICIENCY: 77 (%)
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 635
630
625
620
615
610
605
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 1
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: A-19-005
ENTRY BY: AC
CHECKED BY: KKL
1 2
3 4
5 89
94 94
100
100
0 5
10 15
20 25
30 35
18 DRAFT Appendix C-56 8660F10 April 2023

ASPHALT.

Aggregate Base (AB).

CLAYEY SAND with GRAVEL (SC); medium dense;
brown; moist; few fine GRAVEL; mostly fine SAND;
some low plasticity fines.

GRAVELLY lean CLAY (CL); very stiff to hard; brown;
moist; little coarse to fine GRAVEL; few fine SAND;
mostly medium plasticity, medium toughness fines.

Little medium to fine SAND.

Trace fine SAND.

Lean CLAY with GRAVEL (CL); very stiff; brown;
moist; little coarse to fine GRAVEL; mostly medium
plasticity, low toughness fines.

Bottom of borehole at 21.0 ft bgs
AC = 3"
AB = 3"
Coarse Gravel found in
shoe.
5 6
12 7
5 20
12 32
22 2
4 22
4 50/5
18 25
54 26
50/5
+4.50
+4.50
+4.50
+4.50

13.5 10
116.7
118.3
LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: AC
DRILLING METHOD: Solid-Stem Auger
DRILL RIG: CME 55 Truck
SAMPLER TYPE & SIZE: CAL (2.4" ID)
BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 21 (ft) BACKFILL METHOD: Free Fall
LOG OF BORING A-19-006

LABORATORY
CLIENT: Carollo Engineers
BEGIN DATE: 3/20/2019
COMPLETION DATE: 3/20/2019
SURFACE ELEVATION: 649.1 (ft)*
SURFACE CONDITION: Asphalt
WATER DEPTH: Not Encountered
READING TAKEN: N/A
HAMMER EFFICIENCY: 77 (%)
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 645
640
635
630
625
620
615
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 1
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: A-19-006
ENTRY BY: AC
CHECKED BY: KKL
1 2
3 4
5 100
56 72
67 100
0 5
10 15
20 25
30 35
21 DRAFT Appendix C-57 8660F10 April 2023

Poorly graded GRAVEL with CLAY and SAND
(GP-GC); dense; brown; moist; mostly GRAVEL;
some SAND; few low to medium plasticity, low to
medium toughness fines.

About 52% mostly coarse to fine GRAVEL; about
34% some coarse to fine SAND; few low to medium
plasticity fines.

Poorly graded GRAVEL with SILT (GP-GM); dense;
brown; moist; mostly GRAVEL; little low to medium
plasticity, low to medium toughness fines.

Lean CLAY with SAND (CL); hard; brown; moist;
trace fine GRAVEL; little medium to fine SAND;
mostly medium plasticity, medium toughness fines.

SANDY lean CLAY (CL); very stiff; few fine GRAVEL.

Little fine GRAVEL; some coarse to fine SAND.

Bottom of borehole at 21.5 ft bgs
13 18
23 22
24 20
5 9
16 8
15 20
7 6
7 41
44 25
35 13
+4.50

4.00 1.50

8.2 134.2
LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: AC
DRILLING METHOD: Solid-Stem Auger
DRILL RIG: CME 55 Truck
SAMPLER TYPE & SIZE: CAL (2.4" ID)
BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 21.5 (ft) BACKFILL METHOD: Free Fall
LOG OF BORING A-19-007

LABORATORY
CLIENT: Carollo Engineers
BEGIN DATE: 3/20/2019
COMPLETION DATE: 3/20/2019
SURFACE ELEVATION: 654.3 (ft)*
SURFACE CONDITION: Asphalt
WATER DEPTH: Not Encountered
READING TAKEN: N/A
HAMMER EFFICIENCY: 77 (%)
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 650
645
640
635
630
625
620
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 1
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: A-19-007
ENTRY BY: AC
CHECKED BY: KKL
1 2
3 4
5 83
83 83
100
61 0
5 10
15 20
25 30
35 14
DRAFT Appendix C-58 8660F10 April 2023

ASPHALT.

Aggregate Base (AB).

SANDY lean CLAY (CL); very stiff; reddish brown;
moist; little medium to fine SAND; mostly medium
plasticity, medium toughness fines.

Hard; some medium SAND.

Some fine GRAVEL.

Bottom of borehole at 21.5 ft bgs
15 AC = 3"
AB = 3"
Corrosion
pH = 5.71
Min. Resist. = 10,990
ohm-cm
Chlorides = 0.5 ppm
Sulfates = 5.9 ppm
3 5
8 7
13 20
17 27
30 16
32 43
12 21
40 13
33 57
75 61

3.50 +4.50
+4.50
+4.50
+4.50
23 13.3 118.9
LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: AC
DRILLING METHOD: Solid-Stem Auger
DRILL RIG: CME 55 Truck
SAMPLER TYPE & SIZE: CAL (2.4" ID)
BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 21.5 (ft) BACKFILL METHOD: Free Fall
LOG OF BORING A-19-008

LABORATORY
CLIENT: Carollo Engineers
BEGIN DATE: 3/20/2019
COMPLETION DATE: 3/20/2019
SURFACE ELEVATION: 668 (ft)*
SURFACE CONDITION: Asphalt
WATER DEPTH: Not Encountered
READING TAKEN: N/A
HAMMER EFFICIENCY: 77 (%)
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 665
660
655
650
645
640
635
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 1
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: A-19-008
ENTRY BY: AC
CHECKED BY: KKL
1 2
3 4
5 83
94 100
89 100
0 5
10 15
20 25
30 35
DRAFT Appendix C-59 8660F10 April 2023

Poorly graded GRAVEL with SILT (GP-GM); medium
dense; brown; moist; mostly GRAVEL; some coarse
to fine SAND; few low plasticity fines.

About 60% mostly coarse to fine GRAVEL; about
34% some coarse to fine SAND; few low plasticity
fines.

Dense.

Medium dense.

Dense.

Very dense; few fines.

Very dense.

Bottom of borehole at 35.5 ft bgs
Ground water encountered.

Switched to end discharge
(94mm) mud rotary.
9 10
13 13
17 19
5 8
11 13
9 8
20 22
25 28
35 42
50 23
36 19
17 47
77 3.4

9.3 17.5
115.9
135.2
LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: AC
DRILLING METHOD: Solid-Stem Auger & Rotary
DRILL RIG: CME 75 Track
SAMPLER TYPE & SIZE: Bulk; CAL (2.4" ID)
BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 35.5 (ft) BACKFILL METHOD: Tremie Grout BEGIN DATE: 3/18/2019
COMPLETION DATE: 3/18/2019
SURFACE ELEVATION: 600 (ft)*
SURFACE CONDITION: Soil
HAMMER EFFICIENCY: 70 (%)
LOG OF BORING A-19-009

LABORATORY
CLIENT: Carollo Engineers WATER DEPTH: 14(ft.)
READING TAKEN: 3/17/19
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 595
590
585
580
575
570
565
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 1
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: A-19-009
ENTRY BY: AC
CHECKED BY: KKL
Bulk
1 1
2 3
4 5
6 7
100
89 94
67 19
61 50
0 5
10 15
20 25
30 35
6 9
DRAFT Appendix C-60 8660F10 April 2023

ASPHALT.

Aggregate Base (AB).

CLAYEY SAND with GRAVEL (SC); dense; brown;
moist; about 31% mostly fine GRAVEL; about 46%
little medium SAND; some low to medium plasticity
fines.

SILT with GRAVEL (ML); dense; brown; moist; little
fine GRAVEL; mostly low to medium plasticity fines.

Poorly graded SAND with SILT (SP-SM); very dense;
brown; moist; some GRAVEL; few medium SAND;
mostly low to medium plasticity fines.

Poorly graded SAND with GRAVEL (SP); medium
dense; brown; moist; little fine GRAVEL; mostly
medium SAND; trace fines.

Poorly graded GRAVEL with CLAY (GP-GC);
medium dense; brown; moist; mostly GRAVEL; little
medium SAND; few fines.

Bottom of borehole at 21.5 ft bgs
AC = 3"
AB = 3"
11 16
21 18
13 17
8 23
29 3
8 21
5 14
13 37
30 52
29 27
+4.50

13.8 112.2
LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: AC
DRILLING METHOD: Solid-Stem Auger
DRILL RIG: CME 55 Truck
SAMPLER TYPE & SIZE: Bulk; CAL (2.4" ID)
BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 21.5 (ft) BACKFILL METHOD: Free Fall
LOG OF BORING A-19-010

LABORATORY
CLIENT: Carollo Engineers
BEGIN DATE: 3/20/2019
COMPLETION DATE: 3/20/2019
SURFACE ELEVATION: 687.3 (ft)*
SURFACE CONDITION: Asphalt
WATER DEPTH: Not Encountered
READING TAKEN: N/A
HAMMER EFFICIENCY: 77 (%)
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 685
680
675
670
665
660
655
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 1
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: A-19-010
ENTRY BY: AC
CHECKED BY: KKL
Bulk
1 1
2 3
4 5
100
83 83
94 83
100
0 5
10 15
20 25
30 35
23 DRAFT Appendix C-61 8660F10 April 2023

ASPHALT.

Aggregate Base (AB).

SANDY lean CLAY (CL); very stiff; brown; moist;
trace fine SAND; mostly medium plasticity, medium
toughness fines.

Lean CLAY with GRAVEL (CL); hard; brown; moist;
some fine GRAVEL; mostly medium plasticity fines.

Bottom of borehole at 21.5 ft bgs
23 AC = 3"
AB = 5"
Ground water encountered.

Sample came back
soaked. Large gravel found
in shoe. No recovery.
6 10
17 12
16 16
11 14
15 5
4 32
18 24
28 27
32 29
36 52

3.50 +4.50
+4.50
+4.50
35 20.7 106.2
LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: AC
DRILLING METHOD: Solid-Stem Auger
DRILL RIG: CME 55 Truck
SAMPLER TYPE & SIZE: CAL (2.4" ID)
BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 21.5 (ft) BACKFILL METHOD: Free Fall
BEGIN DATE: 3/20/2019
COMPLETION DATE: 3/20/2019
SURFACE ELEVATION: 653.3 (ft)*
SURFACE CONDITION: Asphalt
HAMMER EFFICIENCY: 77 (%)
LOG OF BORING A-19-011

LABORATORY
CLIENT: Carollo Engineers WATER DEPTH: 12(ft.)
READING TAKEN: 3/2019
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 650
645
640
635
630
625
620
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 1
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: A-19-011
ENTRY BY: AC
CHECKED BY: KKL
1 2
3 4
5 100
100
100
0 44
0 5
10 15
20 25
30 35
52 DRAFT Appendix C-62 8660F10 April 2023

CLAYEY SAND with GRAVEL (SC); dense; tan;
moist; some fine GRAVEL; mostly fine SAND; some
low plasticity fines; weak cementation.

About 26% fine GRAVEL; about 52% mostly fine
SAND; some low plasticity fines.

Very dense; moderate cementation.

Some fine GRAVEL.

Poorly graded GRAVEL with CLAY and SAND
(GP-GC); dense; brown; moist to wet; mostly coarse
to fine GRAVEL; some coarse to fine SAND; little low
to medium plasticity fines.

CLAYEY SAND (SC); very dense; tan; moist; few fine
GRAVEL; mostly medium SAND; some low to
medium plasticity, low to medium toughness fines.

Bottom of borehole at 21.5 ft bgs
AC=3"
AB=3"
Ground water
encountered.
7 14
20 21
30 35
19 25
26 15
15 16
15 30
33 34
65 51
31 63

12.3 120.4
LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: AC
DRILLING METHOD: Solid-Stem Auger
DRILL RIG: CME 55 Truck
SAMPLER TYPE & SIZE: CAL (2.4" ID)
BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 21.5 (ft) BACKFILL METHOD: Free Fall
BEGIN DATE: 3/21/2019
COMPLETION DATE: 3/21/2019
SURFACE ELEVATION: 654.9 (ft)*
SURFACE CONDITION: Asphalt
HAMMER EFFICIENCY: 77 (%)
LOG OF BORING A-19-012

LABORATORY
CLIENT: Carollo Engineers WATER DEPTH: 17(ft.)
READING TAKEN: 3/21/19
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 650
645
640
635
630
625
620
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 1
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: A-19-012
ENTRY BY: AC
CHECKED BY: KKL
1 2
3 4
5 89
100
100
94 100
0 5
10 15
20 25
30 35
22 DRAFT Appendix C-63 8660F10 April 2023

ASPHALT.

Aggregate Base (AB).

CLAYEY SAND with GRAVEL (SC); brown; moist;
little coarse to fine GRAVEL; mostly coarse to fine
SAND; some medium plasticity fines.

Lean CLAY (CL); hard; orange brown; moist; little fine
SAND; mostly medium plasticity fines.

GRAVELLY lean CLAY (CL); hard; brown; dry to
moist; some fine, rounded GRAVEL; little coarse to
fine SAND; mostly medium plasticity fines.

CLAYEY SAND with GRAVEL (SC); dense; moist;
little coarse to fine GRAVEL; mostly coarse to fine
SAND; some medium plasticity fines; weak
cementation; mottled brownish orange and brown.

Very dense.

Dense.

Bottom of borehole at 21.5 ft bgs
18 AC = 3"
AB = 3"
8 10
17 11
19 27
12 16
22 8
17 24
12 21
32 11
14 22
27 46
38 41
53 36
+4.50
+4.50
+4.50
29 21.3
19 104.3
111.1
LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: HFW
DRILLING METHOD: Solid-Stem Auger
DRILL RIG: CME 75 Track
SAMPLER TYPE & SIZE: CAL (2.4" ID)
BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 21.5 (ft) BACKFILL METHOD: Free Fall
LOG OF BORING A-19-013

LABORATORY
CLIENT: Carollo Engineers
BEGIN DATE: 3/21/2019
COMPLETION DATE: 3/21/2019
SURFACE ELEVATION: 641.4 (ft)*
SURFACE CONDITION: Asphalt
WATER DEPTH: Not Encountered
READING TAKEN: N/A
HAMMER EFFICIENCY: 70 (%)
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 640
635
630
625
620
615
610
605
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 1
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: A-19-013
ENTRY BY: AC
CHECKED BY:
1 2
3 4
5 6
89 78
83 83
100
100
0 5
10 15
20 25
30 35
KKL
79 DRAFT Appendix C-64 8660F10 April 2023

Poorly graded GRAVEL with CLAY and SAND
(GP-GC); medium dense; brown; moist; mostly
coarse to fine GRAVEL; mostly coarse to fine SAND;
some medium plasticity fines.

About 54% mostly coarse to fine GRAVEL; about
32% mostly coarse to fine SAND; some medium
plasticity fines.

Loose.

Medium dense.

CLAYEY GRAVEL with SAND (GC); dense; brown;
wet; mostly coarse to fine GRAVEL; little coarse to
fine SAND; some medium plasticity fines.

Very dense.

Bottom of borehole at 21.3 ft bgs
Ground water
encountered.

Cobbles coming up in
cuttings.
4 7
9 5
4 3
5 6
6 4
7 10
11 12
23 21
40 50/4
16 7
12 17
35 90/10

14.3 14.7
113.6
122.3
LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: HFW
DRILLING METHOD: Solid-Stem Auger
DRILL RIG: CME 75 Track
SAMPLER TYPE & SIZE: CAL (2.4" ID)
BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 21.33 (ft) BACKFILL METHOD: Free Fall
BEGIN DATE: 3/22/2019
COMPLETION DATE: 3/22/2019
SURFACE ELEVATION: 638.2 (ft)*
SURFACE CONDITION: Soil
HAMMER EFFICIENCY: 70 (%)
LOG OF BORING A-19-014

LABORATORY
CLIENT: Carollo Engineers WATER DEPTH: 12(ft.)
READING TAKEN: 3/22/19
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 635
630
625
620
615
610
605
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 1
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: A-19-014
ENTRY BY: AC
CHECKED BY: KKL
1 2
3 4
5 6
78 50
61 67
100
38 0
5 10
15 20
25 30
35 14
DRAFT Appendix C-65 8660F10 April 2023

CLAYEY SAND (SC); loose; brown; moist; trace fine
GRAVEL; mostly coarse to fine SAND; some medium
plasticity fines; weak cementation.

SANDY lean CLAY (CL); medium stiff; dark brown;
moist; trace fine, subrounded GRAVEL; some coarse
to fine SAND; mostly medium plasticity, very high dry
strength, medium toughness fines.

Very stiff.

GRAVELLY lean CLAY with SAND (CL); hard; dark
brown; dry to moist; some fine, subangular to
subrounded GRAVEL; little coarse to medium SAND;
mostly medium plasticity fines.

Dark brown, black; moderate cementation.

Bottom of borehole at 20.9 ft bgs
15 Driller note: Material was
very hard.

Ground water
encountered.

Decomposed Rock.
6 6
9 3
4 5
5 9
13 4
16 20
7 21
50/5.5
19 50/5
15 9
22 36
71/12
50/5

0.50 3.50
+4.50
+4.50
23 10.6
LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: HFW
DRILLING METHOD: Solid-Stem Auger
DRILL RIG: CME 75 Track
SAMPLER TYPE & SIZE: CAL (2.4" ID)
BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 20.92 (ft) BACKFILL METHOD: Free Fall
BEGIN DATE: 3/21/2019
COMPLETION DATE: 3/21/2019
SURFACE ELEVATION: 668.7 (ft)*
SURFACE CONDITION: Soil
HAMMER EFFICIENCY: 70 (%)
LOG OF BORING A-19-015

LABORATORY
CLIENT: Carollo Engineers WATER DEPTH: 19(ft.)
READING TAKEN: 3/21/19
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 665
660
655
650
645
640
635
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 1
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: A-19-015
ENTRY BY: AC
CHECKED BY: KKL
1 2
3 4
5 6
61 89
100
89 100
100
0 5
10 15
20 25
30 35
23 DRAFT Appendix C-66 8660F10 April 2023

ASPHALT.

Aggregate Base (AB).

Poorly graded SAND with CLAY and GRAVEL
(SP-SC); medium dense; brown; dry; little fine,
subrounded GRAVEL; mostly coarse to fine SAND;
few nonplastic fines.

Some coarse to fine GRAVEL.

Poorly graded GRAVEL with CLAY and SAND
(GP-GC); medium dense; brown; moist; mostly
coarse to fine, rounded GRAVEL; some coarse to
fine SAND; few nonplastic fines.

Lean CLAY (CL); stiff; orangish brown; moist to wet;
trace fine SAND; mostly medium plasticity fines.

Very stiff.

Bottom of borehole at 21.5 ft bgs
AC = 3"
AB = 3"
Ground water encountered.

Driller Note: Material
became very soft.
12 15
12 6
14 19
5 7
8 2
2 2
1 1
27 22
35 46
27 33
15 4
28 81

1.50 2.50

4.3 4.7

4.3 116.8
121.7
LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: HFW
DRILLING METHOD: Solid-Stem Auger
DRILL RIG: CME 75 Track
SAMPLER TYPE & SIZE: Bulk; CAL (2.4" ID)
BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 21.5 (ft) BACKFILL METHOD: Free Fall
BEGIN DATE: 3/21/2019
COMPLETION DATE: 3/21/2019
SURFACE ELEVATION: 680.2 (ft)*
SURFACE CONDITION: Asphalt
HAMMER EFFICIENCY: 70 (%)
LOG OF BORING A-19-016

LABORATORY
CLIENT: Carollo Engineers WATER DEPTH: 9(ft.)
READING TAKEN: 3/21/19
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 680
675
670
665
660
655
650
645
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 1
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: A-19-016
ENTRY BY: AC
CHECKED BY: KKL
Bulk
1 1
2 3
4 5
6 100
67 67
56 0
100
100
0 5
10 15
20 25
30 35
DRAFT Appendix C-67 8660F10 April 2023

Poorly graded SAND with CLAY and GRAVEL
(SP-SC); dense; gray; moist; mostly coarse to fine
GRAVEL; some medium SAND; trace fines.

SILTY SAND with GRAVEL (SM); dense; gray; moist;
about 36% some fine GRAVEL; about 45% mostly
medium SAND; little fines.

Medium dense; few fines.

Very dense; wet.

Poorly graded SAND with SILT and GRAVEL
(SP-SM); medium dense; brown; wet; some fine
GRAVEL; mostly medium SAND; little fines.

CLAYEY SAND with GRAVEL (SC); very dense; tan;
wet; little fine GRAVEL; mostly medium SAND; some
fines.

Switched to end discharge
(94mm) mud rotary.
6 17
18 6
10 17
15 24
27 15
15 18
11 15
7 15
12 7
30 33
38 35
27 51
33 22
19 71
5 3.6

8.2 10.9

9.8 124.6
141.9
139.2
140.7
LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: AC
DRILLING METHOD: Solid-Stem Auger & Rotary
DRILL RIG: CME 75 Track
SAMPLER TYPE & SIZE: Bulk; CAL (2.4" ID); SPT (1.4" ID) BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 51.5 (ft) BACKFILL METHOD: Tremie Grout LOG OF BORING R-19-017

LABORATORY
CLIENT: Carollo Engineers
BEGIN DATE: 3/19/2019
COMPLETION DATE: 3/19/2019
SURFACE ELEVATION: 601.5 (ft)*
SURFACE CONDITION: Soil
WATER DEPTH: Not Established
READING TAKEN: N/A
HAMMER EFFICIENCY: 70 (%)
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 600
595
590
585
580
575
570
565
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 2
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: R-19-017
ENTRY BY: AC
CHECKED BY: KKL
Bulk
1 1
2 3
4 5
6 7
100
72 67
22 50
17 17
47 0
5 10
15 20
25 30
35 19
13 10
DRAFT Appendix C-68 8660F10 April 2023

CLAYEY SAND with GRAVEL (SC) (continued).

Poorly graded GRAVEL with CLAY and SAND
(GP-GC); dense; tan; wet; mostly GRAVEL; some
medium SAND; few fines.

Very dense.

Bottom of borehole at 51.5 ft bgs
Groundwater not established due to drilling method.
17 21
28 37
50 20
33 35
49 68

FIELD LABORATORY

SAMPLECASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 560
555
550
545
540
535
530
525
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 2 of 2
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: R-19-017
ENTRY BY: AC
CHECKED BY: KKL
8 9
10 50
50 58
40 45
50 55
60 65
70 75
80 DRAFT Appendix C-69 8660F10 April 2023

ASPHALT.

Aggregate Base (AB).

Lean CLAY (CL); hard; brownish orange; moist;
some fine SAND; mostly medium plasticity fines.

Poorly graded SAND (SP); very dense; brown; moist;
few coarse to fine GRAVEL; mostly fine SAND; trace
nonplastic fines; weak cementation.

Lean CLAY (CL); hard; brownish orange; dry; little
fine SAND; mostly medium plasticity fines.

SEDIMENTARY ROCK (CLAYSTONE), intensely
weathered, very soft to soft, Friable, Dark brown,
moderately soft nodules.

Bottom of borehole at 20.8 ft bgs
17 AC = 2"
AB = 2"
Corrosion
pH = 4.90
Min. Resist. = 2,950
ohm-cm
Chlorides =1.7 ppm
Sulfates = 17.6 ppm
5 10
18 15
21 27
40 50
50 42
50/4
40 50/3
28 48
50/4
50/3
+4.50
+4.50
33 17.4

14.9 114.2
123.3
LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: HFW
DRILLING METHOD: Solid-Stem Auger
DRILL RIG: CME 75 Track
SAMPLER TYPE & SIZE: CAL (2.4" ID)
BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 20.75 (ft) BACKFILL METHOD: Free Fall
LOG OF BORING A-19-018

LABORATORY
CLIENT: Carollo Engineers
BEGIN DATE: 3/22/2019
COMPLETION DATE: 3/22/2019
SURFACE ELEVATION: 704.7 (ft)*
SURFACE CONDITION: Asphalt
WATER DEPTH: Not Encountered
READING TAKEN: N/A
HAMMER EFFICIENCY: 70 (%)
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 700
695
690
685
680
675
670
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 1
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: A-19-018
ENTRY BY: AC
CHECKED BY: KKL
1 2
3 4
5 6
100
83 100
100
100
100
0 5
10 15
20 25
30 35
DRAFT Appendix C-70 8660F10 April 2023

ASPHALT.

Lean CLAY (CL); hard; brownish orange; moist;
some fine SAND; mostly medium plasticity fines.

Poorly graded SAND (SP); dense; light gray; dry;
mostly fine SAND; trace nonplastic fines.

Very dense.

Bottom of borehole at 7.8 ft bgs
AC = 2"
10 14
19 13
17 23
50/3
33 40
REF
+4.50
17 115
LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: HFW
DRILLING METHOD: Solid-Stem Auger
DRILL RIG: CME 75 Track
SAMPLER TYPE & SIZE: CAL (2.4" ID)
BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 7.75 (ft) BACKFILL METHOD: Free Fall
BEGIN DATE: 3/22/2019
COMPLETION DATE: 3/22/2019
SURFACE ELEVATION: 709.1 (ft)*
SURFACE CONDITION: Asphalt
HAMMER EFFICIENCY: 70 (%)
LOG OF BORING A-19-019

LABORATORY
CLIENT: Carollo Engineers WATER DEPTH: Not Encountered(ft.) READING TAKEN: N/A
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 705
700
695
690
685
680
675
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 1
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: A-19-019
ENTRY BY: AC
CHECKED BY: KKL
1 2
3 83
83 100
0 5
10 15
20 25
30 35
DRAFT Appendix C-71 8660F10 April 2023

ASPHALT.

Aggregate Base (AB).

Poorly graded SAND with CLAY and GRAVEL
(SP-SC); medium dense; brown; dry; some fine
GRAVEL; mostly coarse to fine SAND; trace
nonplastic fines.

Dense; wet.

CLAYEY SAND with GRAVEL (SC); medium dense;
brown; wet; little coarse to fine GRAVEL; mostly
coarse to fine SAND; some medium plasticity fines.

Poorly graded GRAVEL with SAND (GP); medium
dense; brown; wet; mostly coarse to fine GRAVEL;
some coarse to fine SAND; trace nonplastic fines.

Dense.

Bottom of borehole at 21.5 ft bgs
AC = 3"
AB = 3"
Ground water encountered.
11 14
14 11
18 18
5 6
18 9
11 16
10 22
18 28
36 24
27 40

5.2 4.9

98.4 107.6
LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: HFW
DRILLING METHOD: Solid-Stem Auger
DRILL RIG: CME 75 Track
SAMPLER TYPE & SIZE: CAL (2.4" ID)
BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 21.5 (ft) BACKFILL METHOD: Free Fall
BEGIN DATE: 3/22/2019
COMPLETION DATE: 3/22/2019
SURFACE ELEVATION: 632.5 (ft)*
SURFACE CONDITION: Asphalt
HAMMER EFFICIENCY: 70 (%)
LOG OF BORING A-19-020

LABORATORY
CLIENT: Carollo Engineers WATER DEPTH: 7(ft.)
READING TAKEN: 3/22/19
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 630
625
620
615
610
605
600
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 1
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: A-19-020
ENTRY BY: AC
CHECKED BY: KKL
1 2
3 4
5 39
72 83
39 100
0 5
10 15
20 25
30 35
DRAFT Appendix C-72 8660F10 April 2023

SILTY SAND (SM); brown; moist.

Poorly graded SAND (SP); medium dense; brown;
moist; few fine GRAVEL; mostly medium to fine
SAND; few low plasticity fines.

CLAYEY GRAVEL with SAND (GC); medium dense;
brown; moist; mostly fine GRAVEL; little medium
SAND; little nonplastic to low plasticity fines.

Poorly graded GRAVEL with SAND (GP); dense;
brown; moist; mostly fine GRAVEL; some medium
SAND; trace low plasticity fines.

Poorly graded GRAVEL with CLAY and SAND
(GP-GC); wet.

Little fine SAND.

Poorly graded SAND with GRAVEL (SP); very dense;
brown; wet; some GRAVEL; mostly medium SAND;
few fines.

Bottom of borehole at 36.0 ft bgs Groundwater not established due to drilling method.

Boring caved. Switched to
side discharge mud rotary
with no ground water
measurement.

Push
7 7
9 17
9 13
23 23
17 18
22 20
25 24
27 40
50/5
38 50
14 26
46 40
49 90/11

15.9 12.1

13.1 LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: AC
DRILLING METHOD: Solid-Stem Auger & Rotary
DRILL RIG: CME 75 Track
SAMPLER TYPE & SIZE: Bulk; CAL (2.4" ID)
BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 36 (ft) BACKFILL METHOD: Tremie Grout
LOG OF BORING R-19-021

LABORATORY
CLIENT: Carollo Engineers
BEGIN DATE: 3/15/2019
COMPLETION DATE: 3/18/2019
SURFACE ELEVATION: 596.7 (ft)*
SURFACE CONDITION: Soil
WATER DEPTH: Not Established
READING TAKEN: N/A
HAMMER EFFICIENCY: 70 (%)
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 595
590
585
580
575
570
565
560
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 1
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: R-19-021
ENTRY BY: AC
CHECKED BY: KKL
Bulk
1 1
2 3
4 5
6 7
100
83 56
67 47
67 71
50 0
5 10
15 20
25 30
35 24
3 7
DRAFT Appendix C-73 8660F10 April 2023

ASPHALT.

Aggregate Base (AB).

CLAYEY SAND with GRAVEL (SC); medium dense;
brown; moist; few fine GRAVEL; mostly fine SAND;
some medium plasticity fines.

About 19% fine GRAVEL; about 52% mostly coarse
to fine SAND; some medium plasticity fines.

SANDY lean CLAY (CL); hard; orange brown; moist;
some fine SAND; mostly medium plasticity fines.

CLAYEY SAND (SC); dense; orange brown; moist;
few fine GRAVEL; mostly fine SAND; some medium
plasticity fines.

CLAYEY SAND with GRAVEL (SC); medium dense;
little fine, subangular to subrounded GRAVEL.

Bottom of borehole at 21.5 ft bgs
AC = 3"
AB = 3"
R-Value = 35
Ground water encountered.
6 12
13 11
16 27
6 16
25 15
22 27
7 8
8 25
43 41
49 16
+4.50
+4.50

15.5 18.1
116.2
113.9
LOCATION: Ukiah, CA
DRILLING CONTRACTOR: Geo-Ex Subsurface
HAMMER TYPE: Auto: 140 lb; 30 in Drop
PROJECT NO: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
FIELD
LOGGED BY: HFW
DRILLING METHOD: Solid-Stem Auger
DRILL RIG: CME 75 Track
SAMPLER TYPE & SIZE: Bulk; CAL (2.4" ID)
BOREHOLE DIAMETER: 4 in
DEPTH OF BORING: 21.5 (ft) BACKFILL METHOD: Free Fall
BEGIN DATE: 3/21/2019
COMPLETION DATE: 3/21/2019
SURFACE ELEVATION: 695.1 (ft)*
SURFACE CONDITION: Asphalt
HAMMER EFFICIENCY: 70 (%)
LOG OF BORING A-19-022

LABORATORY
CLIENT: Carollo Engineers WATER DEPTH: 15(ft.)
READING TAKEN: 3/21/19
COUNTY: Mendocino SAMPLE

CASING DEPTH

DESCRIPTION

PLASTICLIMIT

REMARKS
ELEV (ft)DEPTH (ft)
SAMPLE NOBLOWSPER 6 INCHBLOWSPER FOOTGRAPHIC LOGRECOVERY(%)DRILL METHOD 690
685
680
675
670
665
660
POCKETPEN. (TSF)RQD (%)LIQUIDLIMITMOISTURE(%)D. DENSITY(PCF)% PASSING200 SIEVE SHEET 1 of 1
Crawford & Associates, Inc.
1100 Corporate Way, Suite 230
Sacramento, CA 95831
(916) 455-4225
PROJECT NUMBER: 19-503.1
PROJECT: Ukiah RW Pipeline-Phase 4
BORING: A-19-022
ENTRY BY: AC
CHECKED BY: KKL
Bulk
1 1
2 3
4 5
100
100
83 94
100
50 0
5 10
15 20
25 30
35 29
DRAFT Appendix C-74 8660F10 April 2023