PREPARED FOR:

PARIKH CONSULTANTS

1497 NORTH MILPITAS BOULEVARD

MILPITAS, CA 95035

PREPARED BY:

GEOCON CONSULTANTS, INC.

6671 BRISA STREET

LIVERMORE, CA 94550

GEOCON PROJECT NO. E9453-02-01 MARCH 2026

SR-50 Hazel Ave Interchange

Soil Investigation Report

TABLE OF CONTENTS

SOIL INVESTIGATION REPORT Page REPORT LIMITATIONS ............................................................................................................................. i

1.0 INTRODUCTION

1.1 Project Description and Proposed Improvements

1.2 General Objectives

2.0 BACKGROUND

2.1 Hazardous Waste Determination Criteria

2.2 Soil Management Agreement for ADL-Contaminated Soils

2.3 Environmental Screening Levels

3.0 SCOPE OF SERVICES

4.0 INVESTIGATIVE METHODS

4.1 Sampling Procedures

4.2 Laboratory Analyses

4.3 Laboratory QA/QC

5.0 INVESTIGATIVE RESULTS

5.1 Soil Descriptions

5.2 Laboratory Analysis Results

5.3 Statistical Evaluation for Lead Detected in Soil Samples

5.3.1 Calculating the UCLs for the Arithmetic Mean

5.3.2 Correlation of Total and Soluble Lead

6.0 CONCLUSIONS

6.1 Lead in Soil

6.1.1 Group 1 – EB SR-50 Shoulder and Exit Ramp to Hazel Avenue (Borings B1 to B6)

6.1.2 Group 2 – Southbound Hazel Avenue Loop Ramp to EB SR-50 (Borings B7 to B13)

6.1.3 Group 3 – Hazel Avenue Shoulders South of Folsom Boulevard (Borings B14 to B17)

6.1.4 Group 4 – Northbound (NB) Hazel Avenue Shoulder and

Onramp Area to EB SR-50 (Borings B18 to B23)

6.1.5 Group 5 - Eastbound SR-50 Shoulder East of Hazel Avenue (Borings B24 to B33)

6.1.6 Location 6 – Hazel Avenue Area North of SR-50 (Borings B34 to B45)

6.1.7 Location 7 – Westbound SR-50 Shoulder West of Hazel Avenue

(Borings B46 and B47)

6.2 CAM 17 Metals in Soil

6.3 Petroleum Hydrocarbons in Soil

6.4 Organic Compounds in Soil

6.5 Worker Protection

TABLE OF CONTENTS

(continued)

FIGURES

1. Vicinity Map

2. Site Plan

TABLES

1. Summary of DTSC Agreement – Conditions for Soil Reuse and Management

2. Summary of Lead and pH Results

3. Summary of CAM 17 Metals Results

4. Summary of Petroleum Hydrocarbon Results

5. Summary of Organic Compounds Results 6a to 6c. Summary of Lead Statistical Analysis

APPENDICES

A. Soil Management Agreement for ADL-Contaminated Soils B. Encroachment Permits C. Laboratory Reports and Chain-of-Custody Documentation D. Statistical Analyses

SR-50 Hazel Ave Interchange Parikh Consultants Geocon Project No. E9453-02-01 - i - March 19, 2026

REPORT LIMITATIONS

This report has been prepared exclusively for Parikh Consultants. The information contained herein is only valid as of the date of the report and will require an update to reflect additional information obtained.

This report is not a comprehensive site characterization and should not be construed as such. The findings as presented in this report are predicated on the results of the limited sampling and laboratory testing performed. In addition, the information obtained is not intended to address potential impacts related to sources other than those specified herein. Therefore, the report should be deemed conclusive with respect to only the information obtained. We make no warranty, express or implied, with respect to the content of this report or any subsequent reports, correspondence or consultation.

Geocon Consultants, Inc. strived to perform the services summarized herein in accordance with the local standard of care in the geographic region at the time the services were rendered.

The contents of this report reflect the views of the author who is responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the State of California or the Federal Highway Administration. This report does not constitute a standard, specification, or regulation.

GEOCON CONSULTANTS, INC.

Luann Beadle Richard Day, CEG, CHG Senior Project Scientist Senior Geologist

Geocon Project No. E9453-02-01 - 1 - March 19, 2026

SOIL INVESTIGATION REPORT

1.0 INTRODUCTION

This Soil Investigation Report for the State Route 50 (SR-50)/Hazel Avenue Interchange in Rancho Cordova, Sacramento County, California was prepared by Geocon Consultants, Inc. (Geocon) for Parikh Consultants on behalf of Mark Thomas and Company and County of Sacramento.

1.1 Project Description and Proposed Improvements

The Sacramento County Department of Transportation proposes improvements at the SR-50/Hazel Avenue Interchange in Rancho Cordova to improve safety and traffic flow. Planned improvements include:

• Extension of Hazel Avenue south to a proposed intersection with the future Atlanta Street;

• Grade separation of Hazel Avenue over Folsom Boulevard and the Sacramento Placerville Transportation Corridor – Joint Powers Authority rail corridor;

• Construction of a portion of an eastbound transition lane on SR-50 from Hazel Avenue to the gore of the eastbound off-ramp at the Folsom Boulevard interchange;

• Modification of the existing Aerojet Road off-ramp from SR-50;

• Construction of two lane on-ramps in each direction. On-ramps may include meters and carpool lanes;

• Reconstruction of the westbound loop on-ramp;

• Reconstruction of the eastbound diagonal off-ramp;

• Reconstruction of both eastbound on-ramps;

• Construction of eastbound auxiliary lanes for on-ramps and off-ramps, from west of the Hazel Avenue to the eastbound off-ramp, and from the loop on-ramp extending to the Folsom Boulevard interchange;

• Construction of approximately 2,300 feet of Folsom Boulevard roadway improvements including sidewalks, street lighting, and landscaping along the north side, and landscaping and lighting along the south side;

• Construction of Atlanta Street that would connect Folsom Boulevard and the southern extension of Hazel Avenue. This section of Atlanta Street has been referred to as the “jug handle” due to its shape from an aerial perspective; and

• Extension of Hazel Avenue over Folsom Boulevard and the Sacramento Placerville Transportation Corridor-Joint Powers Authority rail corridor.

The project location is depicted on the Vicinity Map, Figure 1.

Geocon Project No. E9453-02-01 - 2 - March 19, 2026

1.2 General Objectives

The purpose of our investigation was to evaluate concentrations of California Administrative Manual 17 (CAM 17) metals, including aerially deposited lead (ADL), total petroleum hydrocarbons as diesel (TPHd), as motor oil (TPHmo), and as gasoline (TPHg), semivolatile organic compounds (SVOCs), organochlorine pesticides (OCPs), and chlorinated herbicides in soil that may be encountered during intersection improvements.

The information obtained from this investigation will be used to evaluate soil handling practices, disposal/reuse options, and worker health and safety.

2.0 BACKGROUND

2.1 Hazardous Waste Determination Criteria

Regulatory criteria to classify a waste as California hazardous for handling and disposal purposes are contained in the CCR, Title 22, Division 4.5, Chapter 11, Article 3, §66261.24. Criteria to classify a waste as Resource, Conservation, and Recovery Act (RCRA) hazardous are contained in Chapter 40 of the Code of Federal Regulations (40 CFR), Section 261.

For waste containing metals, the waste is classified as California hazardous when: 1) the representative total metal content equals or exceeds the respective Total Threshold Limit Concentration (TTLC);

or 2) the representative soluble metal content equals or exceeds the respective Soluble Threshold Limit Concentration (STLC) based on the standard Waste Extraction Test (WET). A waste has the potential of exceeding the STLC when the waste’s total metal content is greater than or equal to 10 times the respective STLC value since the WET uses a 1:10 dilution ratio. Hence, when a total metal is detected at a concentration greater than or equal to 10 times the respective STLC, and assuming that 100 percent of the total metals are soluble, soluble metal analysis is required. A material is classified as RCRA hazardous, or Federal hazardous, when the representative soluble metal content equals or exceeds the Federal regulatory level based on the Toxicity Characteristic Leaching Procedure (TCLP).

The above regulatory criteria are based on chemical concentrations. Wastes may also be classified as hazardous based on other criteria such as ignitability and corrosivity; however, for the purposes of this investigation, toxicity (i.e., representative lead concentrations) is the primary factor considered for waste classification since waste generated during the construction activities would not likely warrant testing for ignitability or other criteria. Waste that is classified as either California hazardous or RCRA hazardous requires management as a hazardous waste.

Geocon Project No. E9453-02-01 - 3 - March 19, 2026

2.2 Soil Management Agreement for ADL-Contaminated Soils

On June 29, 2016, the Department of Toxic Substances Control (DTSC) and Caltrans entered into the Soil Management Agreement for Aerially Deposited Lead-Contaminated Soils (DTSC Agreement) for the management of ADL-contaminated soils generated by Caltrans during State highway projects in all Caltrans districts, statewide.

“Clean soil” is defined as soil, based on a 95 percent upper confidence limit (95% UCL), containing total lead less than or equal to 80 milligrams per kilogram (mg/kg) and soluble WET lead less than 5 milligrams per liter (mg/l), and not containing other constituents at concentrations that pose an unacceptable threat to human health or the environment.

“ADL-contaminated soil” is defined in the DTSC Agreement as excavated soil, based on a 95% UCL, that contains total lead greater than 80 mg/kg and/or soluble WET lead greater than or equal to 5 mg/l.

ADL-contaminated soil reused under the DTSC Agreement must always be at least five feet above the highest groundwater elevation and, depending on lead concentrations, may need to be covered with at least one foot of clean soil or a pavement structure. ADL-contaminated soil may not be placed in areas where it might contact groundwater or surface water (such as streams and rivers) and must be buried in locations that are protected from erosion that may result from storm water run-on and run-off. Additionally, ADL-contaminated soil shall not be placed in or covered by soil with a pH less than 5.0.

ADL-contaminated soil having a pH less than or equal to 5.0 may not be reused and must be properly disposed of.

The DTSC Agreement conditions regarding the reuse and management of soil for construction and maintenance operations are summarized in Table 1, and a copy of the DTSC Agreement is in Appendix A.

2.3 Environmental Screening Levels

The San Francisco Bay Regional Water Quality Control Board (SFRWQCB) has published Environmental Screening Levels (ESLs) for commonly found contaminants in soil, groundwater, soil gas, and surface water, to assist in evaluating sites impacted by releases of hazardous chemicals. The ESLs are commonly used by contractors, soil trucking companies, and private and commercial landowners as default acceptance criteria to evaluate suitability of import soil material. The respective ESLs are listed at the end of Tables 3 through 5 for comparative purposes.

Geocon Project No. E9453-02-01 - 4 - March 19, 2026

3.0 SCOPE OF SERVICES

Geocon performed work under a encroachments permit issued to County of Sacramento by the State of California Department of Transportation (Caltrans Permit 03-25-N-SV-1352) (Appendix A) Geocon also retained the services of Asset Laboratories (Asset) in Las Vegas, Nevada, to perform chemical analyses of soil samples.

On January 26, and 27, 2026, we mobilized to the site and collected samples from 47 borings advanced in unpaved areas of the project using hand auger drilling methods. The samples were submitted to Asset for chemical analysis. This report documents the field sampling and provides recommendations based on the analytical results.

4.0 INVESTIGATIVE METHODS

4.1 Sampling Procedures

Geocon collected soil samples using hand augers. Samples were transferred into stainless steel tubes, and sealed with Teflon tape and plastic end caps, or into resealable plastic bags (total lead analysis only). The Site Plan, Figure 2, shows the approximate boring locations. Sample containers were labeled, placed in a chest cooled with ice as necessary, and transported to Asset using standard Chain-of- Custody (COC) documentation.

4.2 Laboratory Analyses

The samples were analyzed under standard turnaround-times. The laboratory reports and COC documentation are presented in Appendix B. Samples were analyzed as follows:

• 35 samples for CAM 17 metals using EPA Test Methods 6010B and 7471A.

• 61 samples for total lead using EPA Test Method 6010B.

• 9 samples were further analyzed for WET chromium using EPA Test Method 6010B.

• 16 samples were further analyzed for WET lead using EPA Test Method 6010B.

• 6 samples for DI-WET lead using EPA Test Method 6010B.

• 6 samples were further analyzed for TCLP lead using EPA Test Method 6010B.

• 35 samples for TPHd using EPA Test Method 8015B.

• 35 samples for TPHmo using EPA Test Method 8015B.

• 19 samples for TPHg using EPA Test Method 8015B.

• 7 samples for SVOCs using EPA Test Method 8270.

• 14 samples for OCPs using EPA Test Method 8081A.

• 9 samples for organochlorine pesticides using EPA Test Method 8151A.

Geocon Project No. E9453-02-01 - 5 - March 19, 2026

• 6 samples for pH using EPA test method 9045C.

4.3 Laboratory QA/QC

QA/QC procedures were performed for each method of analysis with specificity for each analyte listed in the test method’s QA/QC. The laboratory QA/QC procedures included the following:

• One method blank for every 10 samples, batch of samples or type of matrix, whichever was more frequent.

• One sample analyzed in duplicate for every 10 samples, batch of samples or type of matrix, whichever was more frequent.

• One spiked sample for every 10 samples, batch of samples or type of matrix; whichever was more frequent, with the spike made at 10 times the detection limit or at the analyte level.

Prior to submitting the samples to the laboratories, the COC documentation was reviewed for accuracy and completeness.

5.0 INVESTIGATIVE RESULTS

5.1 Soil Descriptions

Borings were advanced by Geocon within the unpaved areas to a maximum depth of 2.5 feet. Soil encountered generally consisted of brown to dark brown silty sandy to clay with pea gravel and medium to large rocks to the maximum depth of 2.5 feet. Groundwater was not encountered. Refusal was encountered in multiple location as summarized below:

Boring ID Depth of Refusal

(feet) B11, B22, B27, B33, B44, B45, and B47 0.5 B7, B21, B23, and B43 1.0 B1 to B6, B9, B13, B15, B16, B18 to B20, B24 to B26, B28 to B30, B35 to B35, and B38 to B42 1.5 B17 and B46 2.0

5.2 Laboratory Analysis Results

The laboratory analysis results are presented in Tables 2 through 5 and summarized below. Laboratory reports and COC documentation are in Appendix B.

• The following metals were not detected above their respective laboratory reporting limits:

antimony, beryllium, cadmium, selenium, and thallium.

Geocon Project No. E9453-02-01 - 6 - March 19, 2026

• Total chromium was reported at concentrations ranging from 31 milligrams per kilogram (mg/kg) to 64 mg/kg.

• WET chromium was reported at concentrations ranging from not detected (laboratory reporting limit of 0.25 mg/l) to 0.60 mg/l.

• Total lead was reported at concentrations ranging from 3.3 mg/kg to 1,500 mg/kg.

• WET lead was reported at concentrations ranging from 1.9 mg/l to 28 mg/l.

• DI-WET lead was reported at concentrations ranging from 0.12 mg/l to 6.7 mg/l.

• TCLP lead was reported at concentrations ranging from not detected (laboratory reporting limit of 0.050 mg/l) to 2.5 mg/l.

• Remaining CAM 17 metals were reported at concentrations less than 10 times their respective STLC values.

• TPHd was reported at concentrations ranging from not detected (minimum laboratory reporting limit of 10 mg/kg) to 320 mg/kg.

• TPHmo was reported at concentrations ranging from not detected (laboratory reporting limit of 10 mg/kg) to 1,300 mg/kg.

• TPHg was not detected (minimum laboratory reporting limit of 1.0 mg/kg).

• SVOCs were not detected at or above the laboratory reporting limits (minimum laboratory reporting limit of 0.33 mg/kg).

• OCP 4,4´-DDE was detected in one sample at a concentration of 0.290 mg/kg and not detected in the remaining samples.

• Chlorinated herbicides were not detected at or above the laboratory reporting limits (minimum laboratory reporting limit of 0.10 mg/kg).

5.3 Statistical Evaluation for Lead Detected in Soil Samples

Statistical methods were applied to the total lead data to evaluate: 1) the upper confidence limits (UCLs) of the arithmetic means of the total lead concentrations for boring groups at the site; and 2) if an acceptable correlation between total and WET lead concentrations exists that would allow the prediction of WET lead concentrations based on calculated UCLs.

5.3.1 Calculating the UCLs for the Arithmetic Mean

The upper one-sided 95% UCL of the arithmetic mean is defined as the value that, when calculated repeatedly for randomly drawn subsets of site data, equals or exceeds the true mean 95% of the time.

Statistical confidence limits are the classical tool for addressing uncertainties of a distribution mean.

The UCL of the arithmetic mean concentration is used as the mean concentration because it is not possible to know the true mean due to the essentially infinite number of soil samples that could be collected from a site. The UCL therefore accounts for uncertainties due to limited sampling data. As data

Geocon Project No. E9453-02-01 - 7 - March 19, 2026 become less limited at a site, uncertainties decrease and the UCL moves closer to the true mean. ProUCL software was used to calculate the 95% UCLs.

The statistical results are included in Appendix C and summarized in the following tables organized by statistical sample groups:

Group 1 – Eastbound (EB) SR-50 Shoulder and Exit Ramp to Hazel Avenue (Borings B1 to B6)

Sample Interval

(feet)

Total Lead

95% UCL

(mg/kg)

Total Lead Mean

(mg/kg)

Total Lead Minimum (mg/kg)

Total Lead Maximum

(mg/kg) 0 to 0.5 31 20 6.2 41 1 to 1.5 119 78 10 120

Group 2 – Southbound Hazel Avenue Loop Ramp to EB SR-50

(Borings B7 to B13)

Sample Interval

(feet)

Total Lead

95% UCL

(mg/kg)

Total Lead Mean

(mg/kg)

Total Lead Minimum (mg/kg)

Total Lead Maximum

(mg/kg) 0 to 0.5 26 20 6.7 28 1 to 1.5 25 20 12 30 2 to 2.5 19 12 7.1 16

Group 3 – Hazel Avenue Shoulders South of Folsom Boulevard

(Borings B14 to B17)

Sample Interval

(feet)

Total Lead

95% UCL

(mg/kg)

Total Lead Mean

(mg/kg)

Total Lead Minimum (mg/kg)

Total Lead Maximum

(mg/kg) 0 to 0.5 NC 15 5.9 38 1 to 1.5 28 12 3.3 32 2 to 2.5 NC 23 21 25

NC – Not calculated due to insufficient sample population

Group 4 – Northbound (NB) Hazel Avenue Shoulder and Onramp Area to EB SR-50 (Borings B18 to B23)

Sample Interval

(feet)

Total Lead

95% UCL

(mg/kg)

Total Lead Mean

(mg/kg)

Total Lead Minimum (mg/kg)

Total Lead Maximum

(mg/kg) 0 to 0.5 290 154 46 470 1 to 1.5 88 59 25 95

Geocon Project No. E9453-02-01 - 8 - March 19, 2026

Group 5 - Eastbound SR-50 Shoulder East of Hazel Avenue (Borings B24 to B33)

Sample Interval

(feet)

Total Lead

95% UCL

(mg/kg)

Total Lead Mean

(mg/kg)

Total Lead Minimum (mg/kg)

Total Lead Maximum

(mg/kg) 0 to 0.5 30 23 4.2 42 1 to 1.5 26 18 6.8 41 2 to 2.5 NC NC 6.1 6.1

Group 6 – Hazel Avenue Area North of SR-50 (Borings B34 to B45)

Sample Interval

(feet)

Total Lead

95% UCL

(mg/kg)

Total Lead Mean

(mg/kg)

Total Lead Minimum (mg/kg)

Total Lead Maximum

(mg/kg) 0 to 0.5 31 25 9.9 47 1 to 1.5 27 19 6.9 50

2 to 2.5 NC 23 18 28

Group 7 - Westbound SR-50 Shoulder West of Hazel Avenue

(Borings B46 and B47)

Sample Interval

(feet)

Total Lead Mean

(mg/kg)

Total Lead Minimum (mg/kg)

Total Lead Maximum

(mg/kg) 0 to 0.5 810 120 1,500 1 to 1.5 NC 130 130

1.5 to 2 NC 130 130

5.3.2 Correlation of Total and Soluble Lead

Total and corresponding WET lead concentrations are bivariate data with linear structures. These linear structures should allow for the prediction of WET lead concentrations based on the 95% UCL total lead concentrations presented in the tables above.

To estimate the degree of interrelation between total and corresponding WET lead values (x and y, respectively), the correlation coefficient [r] is used. The correlation coefficient is a ratio that ranges from +1 to –1. A correlation coefficient of +1 indicates a perfect direct relationship between two variables; a correlation coefficient of –1 indicates that one variable changes inversely with relation to the other. Between the two extremes is a spectrum of less-than-perfect relationships, including zero, Geocon Project No. E9453-02-01 - 9 - March 19, 2026 which indicates the lack of any sort of linear relationship at all. The correlation coefficient was calculated for 16 (x, y) data points (i.e., soil samples analyzed for both total lead [x] and WET lead [y]). The resulting coefficient of determination (r2) equaled 0.8394, which yields a corresponding correlation coefficient (r) of 0.9162.

For the correlation coefficient that indicates a linear relationship between total and WET lead concentrations, it is possible to compute the line of dependence or a best-fit line between the two variables. A least squares method was used to find the equation of a best-fit line (regression line).

The equation of the regression line for the site was determined to be y = 0.0568(x)-1.1981, where x represents total lead concentrations, y represents predicted WET lead concentrations, 0.0568 is the slope of the line, and -1.1981 is the y intercept.

The equation was used to estimate the WET lead concentrations for the total lead UCLs for the boring groups listed in Section 5.3.1. Regression analysis results and a scatter plot depicting the (x, y) data points along with the regression line are included in Appendix C. The predicted WET lead concentrations are summarized in Tables 6a to 6c.

Geocon Project No. E9453-02-01 - 10 - March 19, 2026

6.0 CONCLUSIONS

6.1 Lead in Soil

6.1.1 Group 1 – EB SR-50 Shoulder and Exit Ramp to Hazel Avenue (Borings B1 to B6)

The following table summarizes the predicted waste classification for excavated soil based on the 95% UCL total lead concentrations for each sample depth, the calculated total lead for the data set as a whole, and the predicted WET lead concentrations for data collected from this portion of the site.

The total and WET lead calculations are summarized below and in Table 6a.

Excavation Depth

95% UCL

Total Lead (mg/kg)

Predicted WET Lead

(mg/l) Waste Classification 0 to 0.5 ft 31 0.6 Non-hazardous (non-regulated) Underlying soil (0.5 to 1.5 ft) 119 5.6 California hazardous (Type R-1)

0 to 1.5 ft 90 3.9 Non-hazardous (Type Com)

In accordance with the DTSC Agreement, soil from 0.5 to 1.5 feet would be considered a regulated material (Type R-1) because the WET lead concentrations are predicted to be greater than the STLC of 5 mg/l and the DI-WET lead concentrations are less than 1.5 mg/l . Soil excavated from this depth interval may be used within Caltrans ROW if placed at least 5 feet above maximum historical water table elevation, covered with at least 1 foot of Type Com or non-regulated material or pavement, and in compliance with the ADL Agreement . Based on TCLP lead concentrations, soil would not be classified as a Federal RCRA waste.

If soil is excavated from 0 to 1.5 ft or deeper and managed as a whole, soil would be considered a regulated material (Type Com) because the predicted 95% total lead concentration is greater than 80 mg/kg and the predicted WET lead concentration is less than the STLC of 5 mg/l. Type Com soil may be re-used within Caltrans ROW with no cover requirement. Soil may also be disposed 1) at an appropriately permitted California Class II or California Class III disposal facility, or 2) on a commercial/industrial property by submitting to DTSC a completed agreement between a contractor and a real property owner for disposing of construction-related material on property owner's property.

6.1.2 Group 2 – Southbound Hazel Avenue Loop Ramp to EB SR-50 (Borings B7 to B13)

In accordance with the DTSC Agreement, soil would be considered non-regulated material for unrestricted use because the maximum total lead concentration of 30 mg/kg is less than 80 mg/kg and

Geocon Project No. E9453-02-01 - 11 - March 19, 2026 less than 50 mg/kg (i.e., less than 10 times the STLC of 5 mg/l). Soil excavated from this location would be classified as non-hazardous to a depth of 2.5 feet based on lead concentrations because the total lead concentrations are less than the TTLC of 1,000 mg/kg and less than 50 mg/kg.

6.1.3 Group 3 – Hazel Avenue Shoulders South of Folsom Boulevard (Borings B14 to B17)

In accordance with the DTSC Agreement, soil would be considered non-regulated material for unrestricted use because the maximum total lead concentration of 38 mg/kg is less than 80 mg/kg and less than 50 mg/kg (i.e., less than 10 times the STLC of 5 mg/l). Soil excavated from this location would be classified as non-hazardous to a depth of 2.5 feet based on lead concentrations because the total lead concentrations are less than the TTLC of 1,000 mg/kg and less than 50 mg/kg.

6.1.4 Group 4 – Northbound (NB) Hazel Avenue Shoulder and Onramp Area to EB SR-50 (Borings B18 to B23)

The following table summarizes the predicted waste classification for excavated soil based on the 95% UCL total lead concentrations for each sample depth, the calculated total lead for the data set as a whole, and the predicted WET lead concentrations for data collected from this portion of the site.

The total and WET lead calculations are summarized below and in Table 6b.

Excavation Depth

95% UCL

Total Lead

(mg/kg)

Predicted WET Lead

(mg/l) Waste Classification 0 to 1 ft 290 15 California hazardous (Type R-2) Underlying soil (1 to 1.5 ft) 88 3.8 Non-hazardous (Type Com)

0 to 1.5 ft 223 11 California hazardous (Type R-2)

In accordance with the DTSC Agreement, soil to a depth of 1 foot would be considered a regulated material (Type R-2) because the WET lead concentrations are predicted to be greater than the STLC of 5 mg/l and the DI-WET lead concentrations are between 1.5 mg/l and 150 mg/l. Type R-2 soil may be used within Caltrans ROW if placed at least 5 feet above maximum historical water table elevation, covered with pavement, and in compliance with the ADL Agreement based on lead concentrations.

Based on TCLP lead concentrations, soil to 1 foot would not be classified as a Federal RCRA waste.

Geocon Project No. E9453-02-01 - 12 - March 19, 2026

Underlying soil would be considered a regulated material (Type Com) that may be used within Caltrans ROW with no cover requirement. Soil may also be disposed 1) at an appropriately permitted California Class II or California Class III disposal facility, or 2) on a commercial/industrial property by submitting to DTSC a completed agreement between a contractor and a real property owner for disposing of construction-related material on property owner's property.

6.1.5 Group 5 - Eastbound SR-50 Shoulder East of Hazel Avenue (Borings B24 to B33)

In accordance with the DTSC Agreement, soil would be considered non-regulated material for unrestricted use because the maximum total lead concentration of 42 mg/kg is less than 80 mg/kg and less than 50 mg/kg (i.e., less than 10 times the STLC of 5 mg/l). Soil excavated from this location would be classified as non-hazardous based on lead concentrations because the total lead concentrations are less than the TTLC of 1,000 mg/kg and less than 50 mg/kg.

6.1.6 Location 6 – Hazel Avenue Area North of SR-50 (Borings B34 to B45)

In accordance with the DTSC Agreement, soil to a depth of 2.5 feet would be considered non-regulated material for unrestricted use because the maximum total lead concentration of 50 mg/kg is less than 80 mg/kg the WET lead concentration of 1.9 mg/l is less than the STLC of 5 mg/l. Soil excavated from this location would be classified as non-hazardous to a depth of 2.5 feet based on lead concentrations because the total lead concentrations are less than the TTLC of 1,000 mg/kg and the maximum STLC concentration is less than 5 mg/l.

6.1.7 Location 7 – Westbound SR-50 Shoulder West of Hazel Avenue (Borings B46 and B47)

The following table summarizes the predicted waste classification for excavated soil based on the 95% UCL total lead or maximum concentrations for each sample depth, the calculated total lead for the data set as a whole, and the predicted WET lead concentrations for data collected from this portion of the site. The total and WET lead calculations are summarized below and in Table 6c.

Geocon Project No. E9453-02-01 - 13 - March 19, 2026

Excavation Depth

95% UCL

Or Maximum*

Total Lead (mg/kg)

Predicted WET Lead

(mg/l) Waste Classification 0 to 1 ft 810 45 California hazardous (Type R-2) Underlying soil (1 to 2 ft) 130 6.2 California hazardous (Type R-2)

0 to 1.5 ft 583 32 California hazardous (Type R-2) Underlying soil (1.5 to 2 ft) 130 6.2 California hazardous (Type R-2)

0 to 2 ft 470 25 California hazardous (Type R-2)

* 95% UCL total lead concentrations could not be calculated due to insufficient sample population

In accordance with the DTSC Agreement, soil would be considered a regulated material (Type R-2) that may be used within Caltrans ROW if placed at least 5 feet above maximum historical water table elevation, covered with pavement, and in compliance with the ADL Agreement based on lead concentrations because the WET lead concentrations are predicted to be greater than the STLC of 5 mg/l and the DI-WET lead concentration is between 1.5 mg/l and 150 mg/l. Based on TCLP lead concentrations, soil to 1 foot would not be classified as a Federal RCRA waste.

6.2 CAM 17 Metals in Soil

Except for lead and chromium, CAM 17 metals were reported in the samples at total concentrations below 10 times their respective STLCs. WET chromium was reported at a concentration of 0.60 mg/l, below its STLC of 5 mg/l. Accordingly, soil would be classified as non-hazardous based on CAM 17 metals concentrations, other than lead as discussed above in Section 6.1.

The CAM 17 metals concentrations in site soil were compared to ESLs. Arsenic and lead were reported at concentrations greater than one or more ESL value. Because concentrations of arsenic and lead exceeded one or more ESL, ProUCL software was used to calculate the 95% UCLs for the site data set as a whole.

The results are included in Appendix C. ESLs, UCLs, and published background concentrations for arsenic and lead are summarized in the following table.

Geocon Project No. E9453-02-01 - 14 - March 19, 2026

Metal Maximum 95%

UCL

Shallow Soil

Residential

ESL

Shallow Soil Commercial/ Industrial ESL

Worker Direct

Exposure

ESL

Published Background

Mean1

Published Background

Range1 Arsenic 9.9 6.1 0.067 0.31 0.98 3.5 0.6 to 11

Lead 1,500 79.6 80 320 160 23.9 12.4 to 97.1 Concentrations reported in mg/kg.

1 Kearney Foundation of Soil Science, March 1996.

Based on the maximum and/or the 95% UCL concentrations for arsenic and lead reuse or disposal of excavated soil may be restricted, depending on proposed use.

Metals results for soil samples are summarized in Table 2 and 3.

6.3 Petroleum Hydrocarbons in Soil

TPHd was reported at a maximum concentration of 320 mg/kg, above the residential exposure ESL of 200 mg/kg, but below the commercial/industrial ESL of 920 mg/kg.

TPHmo was reported at a maximum concentration of 1,300 mg/kg, below the ESLs.

TPHg was not detected at reporting limits below the ESLs.

Total petroleum hydrocarbon results are summarized in Table 4.

6.4 Organic Compounds in Soil

SVOCs were not detected in samples at reporting limits below the ESLs.

OCPs were reported at a maximum concentration of 0.290 mg/kg, below the ESLs.

OCPs were not detected in samples at reporting limits below the ESLs.

Organic Compound results are summarized in Table 5.

6.5 Worker Protection

The contractor(s) should prepare a project-specific health and safety plan to prevent or minimize worker exposure to metals and TPHd. The plan should include protocols for environmental and

Geocon Project No. E9453-02-01 - 15 - March 19, 2026 personnel monitoring, requirements for personal protective equipment, and other health and safety protocols and procedures for the handling of soil.

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TABLE 1

Summary of DTSC Agreement Conditions for Soil Reuse and Management

Material Type

WET Lead (mg/l)

Total Lead (mg/kg)

TCLP Lead (mg/l)

DI-WET Lead (mg/l) Description

<5.0 and ≤80 and <5.0 Non-regulated material for unrestricted use.

Com <5.0 and >80 and ≤320 and <5.0

Regulated material that may be used within Caltrans ROW with no cover requirement. May also be disposed 1) at an appropriately permitted California Class II or California Class III disposal facility, or 2) on a commercial/industrial property by submitting to DTSC a completed agreement between a contractor and a real property owner for disposing of construction-related material on property owner's property.

R-1 ≥5.0 or >320 and ≤1,600 and <5.0 and ≤1.5 Regulated material that may be used within Caltrans ROW if placed at least 5 feet above maximum historical water table elevation, covered with at least 1 foot of Type Com or non-regulated material or pavement, and in compliance with the ADL Agreement.

R-2 ≥5.0 or >1,600 and ≤3,200 and <5.0 and ≤150 Regulated material that may be used within Caltrans ROW if placed at least 5 feet above maximum historical water table elevation, covered with pavement, and in compliance with the ADL Agreement.

Z-0 <5.0 and >320 and <1,000 and <5.0 Regulated surplus material that must be transported to and disposed of at an appropriately permitted California Class II or California Class III disposal facility.

Z-2 ≥5.0 or ≥1,000 and <5.0 Caltrans-generated California hazardous waste that must be transported to and disposed of at a California Class I disposal facility.

Z-2 >3,200 and <5.0 or >150 Caltrans-generated California hazardous waste that must be transported to and disposed of at a California Class I disposal facility.

Z-3 ≥5.0 Caltrans-generated Federal hazardous waste that must be transported to and disposed of at a California Class I disposal facility.

Notes: ADL-contaminated soil shall not be placed in or covered by soil with pH less than 5.0.

ADL-contaminated soil having a pH less than or equal to 5.0 may not be reused and must be properly disposed of.

Geocon, Revised 02-Aug-2017

TABLE 2

Summary of Lead and pH Results

US-50/Hazel Ave Interchange Rancho Cordova, California

Sample

ID

Sample Group

Sample Depth (feet)

Total Lead (mg/kg)

WET Lead (mg/l)

DI-WET

Lead (mg/l)

TCLP Lead (mg/l) pH

B1-0 1 0 to 0.5 8.5 --- --- --- --- B1-1 1 1 to 1.5 10 --- --- --- ---

B2-0 1 0 to 0.5 26 --- --- --- --- B2-1 1 1 to 1.5 120 4.2 --- --- ---

B3-0 1 0 to 0.5 10 --- --- --- --- B3-1 1 1 to 1.5 31 --- --- --- ---

B4-0 1 0 to 0.5 41 --- --- --- --- B4-1 1 1 to 1.5 120 6.2 1.4 0.20 6.8

B5-0 1 0 to 0.5 27 --- --- --- --- B5-1 1 1 to 1.5 120 2.8 --- --- ---

B6-0 1 0 to 0.5 6.2 --- --- --- --- B6-1 1 1 to 1.5 67 3.9 --- --- ---

B7-0 2 0 to 0.5 25 --- --- --- --- B7-0.5 2 0.5 to 1 17 --- --- --- ---

B8-0 2 0 to 0.5 13 --- --- --- --- B8-1 2 1 to 1.5 12 --- --- --- --- B8-2 2 2 to 2.5 12 --- --- --- ---

B9-0 2 0 to 0.5 28 --- --- --- --- B9-1 2 1 to 1.5 24 --- --- --- ---

B10-0 2 0 to 0.5 23 --- --- --- --- B10-1 2 1 to 1.5 20 --- --- --- --- B10-2 2 2 to 2.5 16 --- --- --- ---

B11-0 2 0 to 0.5 26 --- --- --- ---

B12-0 2 0 to 0.5 21 --- --- --- --- B12-1 2 1 to 1.5 17 --- --- --- --- B12-2 2 2 to 2.5 7.1 --- --- --- ---

B13-0 2 0 to 0.5 6.7 --- --- --- --- B13-1 2 1 to 1.5 30 --- --- --- ---

B14-0 3 0 to 0.5 6.2 --- --- --- --- B14-1 3 1 to 1.5 4.4 --- --- --- --- B14-2 3 2 to 2.5 25 --- --- --- ---

B15-0 3 0 to 0.5 5.9 --- --- --- --- B15-1 3 1 to 1.5 3.3 --- --- --- ---

E9453-02-01 Tables Page 1 of 3 March 2026

US-50/Hazel Ave Interchange Rancho Cordova, California

Sample

ID

Sample Group

Sample Depth (feet)

Total Lead (mg/kg)

WET Lead (mg/l)

DI-WET

Lead (mg/l)

TCLP Lead (mg/l) pH

B16-0 3 0 to 0.5 7.9 --- --- --- --- B16-1 3 1 to 1.5 7.6 --- --- --- ---

B17-0 3 0 to 0.5 38 --- --- --- --- B17-1 3 1 to 1.5 32 --- --- --- ---

B17-1.5 3 1.5 to 2 21 --- --- --- ---

B18-0 4 0 to 0.5 470 28 2.4 0.27 6.1 B18-1 4 1 to 1.5 29 --- --- --- ---

B19-0 4 0 to 0.5 98 4.7 --- --- --- B19-1 4 1 to 1.5 75 4.0 --- --- ---

B20-0 4 0 to 0.5 55 2.6 --- --- --- B20-1 4 1 to 1.5 69 4.7 --- --- ---

B21-0 4 0 to 0.5 46 --- --- --- --- B21-0.5 4 0.5 to 1 95 3.7 --- --- ---

B22-0 4 0 to 0.5 53 1.9 --- --- ---

B23-0 4 0 to 0.5 200 2.2 --- --- --- B23-0.5 4 0.5 to 1 25 --- --- --- ---

B24-0 5 0 to 0.5 22 --- --- --- --- B24-1 5 1 to 1.5 41 --- --- --- ---

B25-0 5 0 to 0.5 42 --- --- --- --- B25-1 5 1 to 1.5 27 --- --- --- ---

B26-0 5 0 to 0.5 4.2 --- --- --- --- B26-1 5 1 to 1.5 6.8 --- --- --- ---

B27-0 5 0 to 0.5 32 --- --- --- ---

B28-0 5 0 to 0.5 6.9 --- --- --- --- B28-1 5 1 to 1.5 15 --- --- --- ---

B29-0 5 0 to 0.5 20 --- --- --- --- B29-1 5 1 to 1.5 23 --- --- --- ---

B30-0 5 0 to 0.5 20 --- --- --- --- B30-1 5 1 to 1.5 13 --- --- --- ---

B31-0 5 0 to 0.5 31 --- --- --- --- B31-1 5 1 to 1.5 8.4 --- --- --- --- B31-2 5 2 to 2.5 6.1 --- --- --- ---

B32-0 5 0 to 0.5 23 --- --- --- --- B32-1 5 1 to 1.5 7.3 --- --- --- ---

B33-0 5 0 to 0.5 28 --- --- --- ---

B34-0 6 0 to 0.5 27 --- --- --- --- B34-1 6 1 to 1.5 31 --- --- --- --- B34-2 6 2 to 2.5 28 --- --- --- ---

E9453-02-01 Tables Page 2 of 3 March 2026

US-50/Hazel Ave Interchange Rancho Cordova, California

Sample

ID

Sample Group

Sample Depth (feet)

Total Lead (mg/kg)

WET Lead (mg/l)

DI-WET

Lead (mg/l)

TCLP Lead (mg/l) pH

B35-0 6 0 to 0.5 9.9 --- --- --- --- B35-1 6 1 to 1.5 12 --- --- --- ---

B36-0 6 0 to 0.5 44 --- --- --- --- B36-1 6 1 to 1.5 16 --- --- --- ---

B37-0 6 0 to 0.5 21 --- --- --- --- B37-1 6 1 to 1.5 24 --- --- --- --- B37-2 6 2 to 2.5 18 --- --- --- ---

B38-0 6 0 to 0.5 33 --- --- --- --- B38-1 6 1 to 1.5 50 1.9 --- --- ---

B39-0 6 0 to 0.5 22 --- --- --- --- B39-1 6 1 to 1.5 8.3 --- --- --- ---

B40-0 6 0 to 0.5 15 --- --- --- --- B40-1 6 1 to 1.5 18 --- --- --- ---

B41-0 6 0 to 0.5 14 --- --- --- --- B41-1 6 1 to 1.5 16 --- --- --- ---

B42-0 6 0 to 0.5 47 --- --- --- --- B42-1 6 1 to 1.5 6.9 --- --- --- ---

B43-0 6 0 to 0.5 16 --- --- --- --- B43-0.5 6 0.5 to 1 7.0 --- --- --- ---

B44-0 6 0 to 0.5 20 --- --- --- ---

B45-0 6 0 to 0.5 31 --- --- --- ---

B46-0 7 0 to 0.5 120 6.4 0.12 <0.050 6.2 B46-1 7 1 to 1.5 130 7.6 0.16 <0.050 6.5

B46-1.5 7 1.5 to 2 130 8.0 0.18 0.062 6.8

B47-0 7 0 to 0.5 1,500 --- 6.7 2.8 6.8

Hazardous Waste Criteria TTLC (mg/kg) 1,000 --- --- --- ---

STLC (mg/l) --- 5.0 --- --- --- TCLP (mg/l) --- --- --- --- 5.0

Notes:

mg/kg = Milligrams per kilogram mg/l = Milligrams per liter WET = Waste Extraction Test using citric acid as the extraction fluid

STLC = Soluble Threshold Limit Concentration TCLP = Toxicity Characteristic Leaching Procedure TTLC = Total Threshold Limit Concentration

E9453-02-01 Tables Page 3 of 3 March 2026

TABLE 3

Summary of CAM 17 Metals Results

US-50/Hazel Ave Interchange Rancho Cordova, California

Sample

ID

Sample Depth (ft) A nt im on y

A rs en ic

Ba ri um

Be ry lli um

C ad m iu m

C hr om iu m

C ob al t

C op pe r

Le ad

M er cu ry

M ol yb de nu m

N ic ke l

Se le ni um

Si lv er

Th al liu m

V an ad iu m

Zi nc

B1-0 0 to 0.5 <2.0 5.7 110 <1.0 <1.0 41 8.1 46 8.5 <0.10 <1.0 30 <1.0 <1.0 <2.0 51 83

B2-1 1 to 1.5 <2.0 4.1 80 <1.0 <1.0 39 8.3 39 120 <0.099 <1.0 32 <1.0 <1.0 <2.0 44 99

B4-0 0 to 0.5 <2.0 4.1 110 <1.0 <1.0 34 9.0 45 41 <0.10 1.5 30 <1.0 <1.0 <2.0 47 130

B5-1 1 to 1.5 <2.0 6.0 180 <1.0 <1.0 50 0.44

13 49 120 <0.099 <1.0 44 <1.0 <1.0 <2.0 72 100

B7-0 0 to 0.5 <2.0 5.3 130 <1.0 <1.0 43 9.9 38 25 <0.098 <1.0 35 <1.0 <1.0 <2.0 53 92

B8-1 1 to 1.5 <2.0 6.7 140 <1.0 <1.0 56 <0.25

14 38 12 <0.10 <1.0 49 <1.0 <1.0 <2.0 69 61

B9-1 1 to 1.5 <2.0 5.6 180 <1.0 <1.0 40 14 49 24 <0.10 <1.0 38 <1.0 <1.0 <2.0 61 110

B10-0 0 to 0.5 <2.0 9.2 200 <1.0 <1.0 45 19 41 23 <0.10 <1.0 41 <1.0 1.0 <2.0 62 100

B12-1 1 to 1.5 <2.0 5.0 120 <1.0 <1.0 57 0.31

13 41 17 <0.10 <1.0 110 <1.0 <1.0 <2.0 59 120

B13-0 0 to 0.5 <2.0 3.4 66 <1.0 <1.0 40 7.1 32 6.7 <0.099 <1.0 24 <1.0 <1.0 <2.0 48 120

B14-1 1 to 1.5 <2.0 4.4 150 <1.0 <1.0 49 12 29 4.4 <0.099 <1.0 39 <1.0 <1.0 <2.0 69 45

B16-0 0 to 0.5 <2.0 7.6 140 <1.0 <1.0 51 0.26

13 46 7.9 <0.10 <1.0 41 <1.0 <1.0 <2.0 75 56

B17-1 1 to 1.5 <2.0 5.1 71 <1.0 <1.0 36 9.0 37 32 <0.099 <1.0 32 <1.0 <1.0 <2.0 52 52

B19-0 0 to 0.5 <2.0 4.8 120 <1.0 <1.0 44 11 57 98 0.13 <1.0 39 <1.0 <1.0 <2.0 50 270

B20-1 1 to 1.5 <2.0 5.6 130 <1.0 <1.0 45 10 51 69 <0.10 <1.0 39 <1.0 <1.0 <2.0 56 140

B21-0.5 0.5 to 1 <2.0 6.7 82 <1.0 <1.0 42 8.9 39 95 <0.10 <1.0 35 <1.0 <1.0 <2.0 45 72

B22-0 0 to 0.5 <2.0 5.4 160 <1.0 <1.0 43 10 53 53 <0.099 1.1 36 <1.0 <1.0 <2.0 54 230

B23-0.5 0.5 to 1 <2.0 5.0 82 <1.0 <1.0 37 8.7 40 25 <0.099 <1.0 32 <1.0 <1.0 <2.0 47 64

US-50/Hazel Ave Interchange Rancho Cordova, California

Sample

ID

Sample Depth (ft) A nt im on y

A rs en ic

Ba ri um

Be ry lli um

C ad m iu m

C hr om iu m

C ob al t

C op pe r

Le ad

M er cu ry

M ol yb de nu m

N ic ke l

Se le ni um

Si lv er

Th al liu m

V an ad iu m

Zi nc

B24-1 1 to 1.5 <2.0 8.2 170 <1.0 <1.0 45 14 40 41 <0.10 <1.0 39 <1.0 <1.0 <2.0 61 92

B25-0 0 to 0.5 <2.0 5.3 130 <1.0 <1.0 42 11 48 42 <0.10 <1.0 44 <1.0 <1.0 <2.0 59 80

B26-1 1 to 1.5 <2.0 5.7 120 <1.0 <1.0 64 <0.25

14 41 6.8 <0.10 <1.0 53 <1.0 <1.0 <2.0 72 64

B28-0 0 to 0.5 <2.0 4.9 110 <1.0 <1.0 43 10 39 6.9 <0.098 <1.0 29 <1.0 <1.0 <2.0 59 92

B29-1 1 to 1.5 <2.0 6.4 140 <1.0 <1.0 57 <0.25

15 40 23 0.19 <1.0 39 <1.0 <1.0 <2.0 78 55

B30-1 1 to 1.5 <2.0 4.3 110 <1.0 <1.0 39 9.8 34 13 <0.10 <1.0 37 <1.0 <1.0 <2.0 52 46

B31-0 0 to 0.5 <2.0 4.0 110 <1.0 <1.0 34 9.9 34 31 <0.10 <1.0 29 <1.0 <1.0 <2.0 55 84

B32-1 1 to 1.5 <2.0 3.7 93 <1.0 <1.0 33 9.9 32 7.3 <0.098 <1.0 32 <1.0 <1.0 <2.0 51 42

B34-0 0 to 0.5 <2.0 8.1 120 <1.0 <1.0 45 11 52 27 <0.098 1.2 39 <1.0 <1.0 <2.0 54 150

B35-1 1 to 1.5 <2.0 7.3 150 <1.0 <1.0 64 0.41

17 55 12 <0.10 <1.0 55 <1.0 <1.0 <2.0 89 69

B37-0 0 to 0.5 <2.0 4.3 110 <1.0 <1.0 36 8.7 74 21 <0.10 <1.0 31 <1.0 <1.0 <2.0 44 150

B38-1 1 to 1.5 <2.0 6.4 130 <1.0 <1.0 61 0.60

13 48 50 <0.10 <1.0 55 <1.0 <1.0 <2.0 65 130

B39-1 1 to 1.5 <2.0 4.4 80 <1.0 <1.0 31 8.2 38 8.3 <0.10 <1.0 33 <1.0 <1.0 <2.0 36 74

B40-0 0 to 0.5 <2.0 3.7 130 <1.0 <1.0 40 8.7 46 15 <0.10 2.0 31 <1.0 <1.0 <2.0 45 180

B41-1 1 to 1.5 <2.0 6.0 140 <1.0 <1.0 51 0.40

12 43 16 <0.10 <1.0 51 <1.0 <1.0 <2.0 64 61

B43-0 0 to 0.5 <2.0 5.3 85 <1.0 <1.0 36 11 38 16 <0.10 <1.0 35 <1.0 <1.0 <2.0 47 71

B46-0 0 to 0.5 <2.0 9.9 140 <1.0 <1.0 49 12 55 120 <0.098 <1.0 42 <1.0 <1.0 <2.0 60 150

US-50/Hazel Ave Interchange Rancho Cordova, California

Sample

ID

Sample Depth (ft) A nt im on y

A rs en ic

Ba ri um

Be ry lli um

C ad m iu m

C hr om iu m

C ob al t

C op pe r

Le ad

M er cu ry

M ol yb de nu m

N ic ke l

Se le ni um

Si lv er

Th al liu m

V an ad iu m

Zi nc

Hazardous Waste Criteria TTLC (mg/kg) 500 500 10,000 75 100 2,500 8,000 2,500 1,000 20 3,500 2,000 100 500 700 2,400 5,000

STLC (mg/l) 15 5.0 100 0.75 1.0 5.0 80 25 5.0 0.2 350 20 1.0 5.0 7.0 24 250 TCLP (mg/l) --- 5.0 100 --- 1.0 5.0 --- --- 5.0 0.2 --- --- 1.0 5.0 --- --- ---

ESLs Residential Direct Exposure 31 0.032 15,000 16 7.1 85,000* 23 3,100 80 0.67 390 820 390 390 0.78 390 23,000

Commercial/Industrial Direct Exposure 470 0.14 220,000 230 100 360,000* 350 47,000 500 2.9 5,800 11,000 5,800 5,800 12 5,800 350,000

Background Concentrations (1)

Minimum 0.15 0.6 133 0.25 0.05 23 2.7 9.1 12.4 0.10 0.1 9.0 0.015 0.10 0.17 39 88 Mean 0.60 3.5 509 1.28 0.36 122 14.9 28.7 23.9 0.26 1.3 57 0.058 0.80 0.56 112 149

Maximum 1.95 11 1,400 2.70 1.70 1,579 46.9 96.4 97.1 0.90 9.6 509 0.430 8.30 1.10 288 236

Notes:

TTLC = Total Threshold Limit Concentration --- = Not analyzed or no standard exists STLC = Soluble Threshold Limit Concentration * = ESL values shown are for chromium III. ESL values for total chromium have not been established TCLP = Toxicity Characteristic Leaching Procedure ESLs = Environmental Screening Levels, SFRWQCB, 2025 (Rev 4)

Results are shown in milligrams per kilogram (mg/kg) 1 = Background Concentrations of Trace and Major Elements in California Soils (Kearney Foundation < = Not detected at or above laboratory reporting limit of Soil Science, Division of Agricultural and Natural Resources, University of California, March 1996)

TABLE 4

Summary of Petroleum Hydrocarbon Results

US-50/Hazel Ave Interchange Rancho Cordova, California

Sample ID Sample

Depth (ft) TPHd TPHmo TPHg

B1-0 0 to 0.5 87 280 ---

B2-1 1 to 1.5 86 270 <1.0

B4-0 0 to 0.5 100 370 ---

B5-1 1 to 1.5 110 370 <1.0

B7-0 0 to 0.5 75 300 ---

B8-1 1 to 1.5 28 76 <1.0

B9-1 1 to 1.5 46 130 <1.0

B10-0 0 to 0.5 38 100 ---

B12-1 1 to 1.5 46 110 <1.0

B13-0 0 to 0.5 11 16 ---

B14-1 1 to 1.5 11 15 <50

B16-0 0 to 0.5 22 50 ---

B17-1 1 to 1.5 <10 14 <1.0

B19-0 0 to 0.5 55 190 ---

B20-1 1 to 1.5 120 460 <1.0

B21-0.5 0.5 to 1 54 150 <1.0

B22-0 0 to 0.5 100 370 ---

B23-0.5 0.5 to 1 54 160 <1.0

B24-1 1 to 1.5 13 16 <1.0

B25-0 0 to 0.5 39 110 ---

B26-1 1 to 1.5 <10 <10 <1.0

US-50/Hazel Ave Interchange Rancho Cordova, California

Sample ID Sample

Depth (ft) TPHd TPHmo TPHg

B28-0 0 to 0.5 110 450 ---

B29-1 1 to 1.5 <10 16 <1.0

B30-1 1 to 1.5 <10 <10 <1.0

B31-0 0 to 0.5 12 28 ---

B32-1 1 to 1.5 13 28 <1.0

B34-0 0 to 0.5 45 110 ---

B35-1 1 to 1.5 <10 12 <1.0

B37-0 0 to 0.5 83 330 ---

B38-1 1 to 1.5 21 55 <1.0

B39-1 1 to 1.5 32 91 <1.0

B40-0 0 to 0.5 320 1,300 ---

B41-1 1 to 1.5 240 890 <1.0

B43-0 0 to 0.5 130 710 ---

B46-0 0 to 0.5 62 200 ---

Residential Direct Exposure 200 12,000 460 Commercial/Industrial Direct Exposure 920 180,000 2,100

ESLs

US-50/Hazel Ave Interchange Rancho Cordova, California

Sample ID Sample

Depth (ft) TPHd TPHmo TPHg

Notes:

Results shown in milligrams per kilogram (mg/kg)

TPHd = Total petroleum hydrocarbons as diesel TPHmo = Total petroleum hydrocarbons as motor oil

TPHg = Total petroleum hydrocarbons as gasoline < = Not detected at or above shown laboratory reporting limit

--- = Not analyzed or no standard exists ESLs = Environmental Screening Levels, SFRWQCB, 2025 (Rev 4)

TABLE 5

Summary of Organic Compounds Results

US-50/Hazel Ave Interchange Rancho Cordova, California

Sample ID Sample

Depth (ft) SVOCs OCPs Chlorinated Herbicides

B1-0 0 to 0.5 --- ND ---

B4-0 0 to 0.5 --- ND ---

B7-0 0 to 0.5 --- ND ---

B10-0 0 to 0.5 --- ND ---

B13-0 0 to 0.5 ND ND ND

B14-0 0 to 0.5 ND --- ND

B15-0 0 to 0.5 ND --- ND

B16-0 0 to 0.5 ND ND ND

B17-0 0 to 0.5 ND --- ND

B18-0 0 to 0.5 ND --- ND

B19-0 0 to 0.5 ND ND ND

B22-0 0 to 0.5 --- ND ---

B25-0 0 to 0.5 --- ND ---

B28-0 0 to 0.5 --- ND ---

B31-0 0 to 0.5 --- ND ---

B34-0 0 to 0.5 --- 4,4-DDE = 0.290 ---

B37-0 0 to 0.5 --- ND ND

B40-0 0 to 0.5 --- ND ---

B42-0 0 to 0.5 --- --- ND

Residential Direct Exposure --- p,p-DDE = 2.0 --- Commercial/Industrial Direct Exposure --- p,p-DDE = 9.3 ---

ESLs

E9453-02-01 Tables Page 1 of 2 March 2026

TABLE 5

Summary of…