Appendix M - Sediment Testing Sample Report Format.pdf

Contractor or Sub-Contractor May Vary the Example Report Format but the Contents of the Report must Contain at a Minimum Those Items Covered in the Example as Deliverables to be Reviewed by USACE for Approval Purposes.

Firm Name i

TABLE OF CONTENTS

Page

1.0 INTRODUCTION

2.0 BACKGROUND

3.0 PURPOSE

3.1 SCOPE OF WORK

3.2 SUMMARY OF INVESTIGATION APPROACH

4.0 PREFIELD ACTIVITIES

5.0 FIELD ACTIVITIES

5.1 FIELD SAMPLING

5.2 SEDIMENT SAMPLING, COLLECTION LOCATIONS, AND DEVIATIONS

5.2.1 Composite Sediment Sampling for Chemical Analyses and Collection Locations

5.2.2 Targeted Sediment Sample for Chemical Analyses

5.2.3 Discrete Sediment Samples for Geotechnical Testing

5.2.4 Field Sampling Deviation

5.3 DOCUMENTATION AND LITHOLOGIC LOGGING

6.0 LABORATORY TESTING

6.1 SAMPLES FOR CHEMICAL ANALYSES

6.2 CHEMICAL TESTING AND DEVIATIONS

6.2.1 Chemical Testing

6.2.2 Analytical Program Deviations

6.3 GEOTECHNICAL TESTING AND DEVIATIONS

6.3.1 Geotechnical Testing

6.3.2 Geotechnical Testing Deviations

7.0 RESULTS AND DATA EVALUATION

7.1 SUMMARY OF CHEMICAL ANALYTICAL RESULTS

7.2 DATA QUALITY REVIEW OF CHEMICAL DATA

7.3 CHEMICAL DATA EVALUATION

7.3.1 Regional Screening Levels

7.3.2 Waste Characterization Criteria

7.4 GEOTECHNICAL RESULTS

8.0 DISCUSSION OF DISPOSAL OPTIONS

9.0 SUMMARY AND CONCLUSIONS

10.0 REFERENCES

TABLE OF CONTENTS

(Continued)

Firm Name ii

TABLES

Table 1 Sample Locations and Depths for Composite and Targeted Sediment Samples Table 2 Sediment Sample Chemical Composites Table 3 Analytical Results for TRPH, PCBs, VOCs, Organochlorine Pesticides, and

PAHs in Sediment Samples Table 4 Analytical Results for pH and Metals in Sediment Samples Table 5 Analytical Results for Soluble Lead in Sediment Samples

FIGURES

Figure 1 Site Location Map Figure 2 Sediment Sample Locations

APPENDIXES

Appendix A USACE’s Scope of Work – Per Level II Project Request Appendix B Sampling and Analysis Plan Appendix C Photo Log Appendix D Trench Logs Appendix E Analytical Chemical Testing Laboratory Report and Chain-of-Custody

Documentation Appendix F Geotechnical Testing Laboratory Reports Appendix G Summary Data Quality Review Appendix H Disposal Option Forms and ROM Cost Estimate

Firm Name

DATA TRANSMITTAL REPORT

Location Sediment Sampling and Analysis

Los Angeles, California

1.0 INTRODUCTION

Firm Name has prepared this Data Transmittal Report (Report) on behalf of the United States Army Corps of Engineers, Los Angeles District (USACE) to present the findings of the sediment sampling, chemical testing, and geotechnical testing of sediments at the (Example) Location, between Fletcher Drive and the Glendale Freeway (California State Route 2), located in Los Angeles, California (the Site or Reach 5C; Figure 1). This Report was prepared in general accordance with the USACE’s Scope of Work dated February 14, 2017 (SOW;

Appendix A) and the April 4, 2017 Sampling and Analysis Plan prepared by Firm Name (SAP;

Appendix B).

2.0 BACKGROUND

(Example) As part of the emergency flood risk management associated with the forecasted 2016 El Nino winter storm season (Regional General Permit No. 63, Regulatory Memorandum For Record Dates 07JAN2016), a Categorical Exclusion plan dated February 2016 was prepared by the USACE. This Categorical Exclusion plan proposes to remove exotic-invasive vegetation from the Site. Sediment deposition within Reach 5C has resulted in a sediment bar that contains a high percentage of cobble-sized clasts, extends across approximately 215 feet of the channel, and covers an area of approximately 4.0 acres. The bar limits flow conveyance and confines the current thalweg to widths ranging from approximately 12 to 30 feet near the south side of the river embankment (USACE, 2016).

The USACE proposes to remove and transport off-site for disposal/reuse approximately Number cubic yards (CY) of sediment accumulated in the sediment bar of Reach 5C. Based on our review of the approximate elevations and the design elevation provided by the USACE for this project, the sediments to be removed range in thickness from approximately 2 to 8 feet.

The area within which sediments are to be characterized was identified as approximately 174,500 square feet, or approximately 4 acres. The USACE has not identified the location for disposal/reuse of the sediments. The chemical and geotechnical properties of the sediments were evaluated to assess their suitability for potential disposal/reuse at offsite locations.

This project was authorized as follows: “IAW Memorandum for the Record dated 28 Jan 2016, Recommended Repair of Levee Toe Erosion Damage and Other O&M Work, Los Angeles

River, paragraph 7- Los Angeles River sediment needs to be removed and disposed of properly based on sediment contamination.”

3.0 PURPOSE

The purpose of this project was to obtain data for use in identifying and evaluating potential disposal/reuse options for the sediment.

3.1 SCOPE OF WORK

The SOW for investigation of the site closely followed the SOW issued to Firm Name by the USACE and included the following:

• prepared a SAP;

• performed a bird nesting survey prior to sampling each day (completed by a biologist with the USACE);

• collected sediment samples at various depths from 25 locations at the Site using a backhoe;

• performed chemical analyses on composite, targeted, and discrete sediment samples;

• performed geotechnical testing of discrete sediment samples;

• prepared lithologic logs of all trenches;

• evaluated the results of the chemical and geotechnical testing to identify potential disposal/reuse options for the sediment proposed for removal from location;

• maintained quality assurance and quality control; and

• prepared this report.

3.2 SUMMARY OF INVESTIGATION APPROACH

Based on the Site area (approximately 174,500 square feet) and estimated volume (50,000 CY) of sediments to be removed, the sampling program included the collection of 50 sediment samples from 25 locations (Firm Name, 2017). The sampling program was based on a sampling grid of approximately 85 by 85 feet. The actual sampling locations were selected in the field based on logistical conditions and access available during field work. In addition, one targeted sample was collected from sediments that exhibited slight discoloration and an elevated photoionization detector (PID) measurement relative to other sediment samples collected from the Site.

Sediment samples for chemical analysis, except for the targeted sample, were composited by the analytical laboratory for analyses in accordance with the SAP. The targeted sediment sample was analyzed for the same constituents as the composite samples. Three discrete sediment samples were collected for geotechnical testing in accordance with the SAP.

Results for total lead in the composite samples indicated concentrations of total lead that exceeded10 times the soluble threshold limit concentration (STLC) and/or 20 times the toxicity characteristic leaching procedure (TCLP) for lead. Consequently, soluble lead analyses were performed on composite samples and total and soluble lead analyses were performed on discrete sediment samples selected based on the total lead concentrations of their corresponding composite samples. Soluble lead results for several of these discrete sediment samples exceeded the STLC for lead. To provide a more representative data set for soluble lead, with USACE’s approval, the remaining discrete sediment samples collected during this investigation were analyzed for STLC for lead.

To evaluate the sediment proposed for removal from the Site, Firm Name completed the following.

• Chemical results were compared to their respective United States Environmental Protection Agency (EPA) Region 9 Regional Screening Levels (RSLs) for Chemical Contaminants at Superfund Sites (EPA, 2016), California Department of Toxic Substances Control (DTSC)-modified screening levels (DTSC-SLs) for residential and commercial/industrial soils (DTSC, 2016), and/or waste characterization criteria (STLC, TCLP and total threshold limit concentration [TTLC]). Arsenic concentrations in sediment were compared to the DTSC Los Angeles County upper bound limits (DTSC, 2008), rather than the RSLs or DTSC-SLs. Consistent with DTSC screening level policy (DTSC, 2016), lead concentrations in sediment were compared to the DTSC LeadSpread 8 screening levels for residential and commercial/industrial land use (DTSC, 2011), rather than the RSLs.

• Performed a statistical analysis of the soluble (STLC) lead data, in general accordance with Chapter 9 of the EPA publication SW-846, Test Methods for Evaluating Solid Waste, Physical/Chemical Methods (SW-846). Using these methods the 95 percent (%) upper confidence limit (UCL) of the mean for soluble (STLC) lead in discrete sediment samples collected at the Site was calculated.

4.0 PREFIELD ACTIVITIES

Prefield activities performed by Firm Name included: (1) preparing a SAP specific to this project; (2) subcontracting with a backhoe operator and laboratories capable of performing the required chemical and geotechnical testing of the sediment samples; (3) notifying Underground Service Alert of our planned activities.

Firm Name prepared the SAP in accordance with the USACE’s SOW. The SAP was submitted to and approved by the USACE before commencing the field work. A copy of the SAP is included in Appendix B.

Firm Name subcontracted IO Environmental & Infrastructure Inc. (IOEI) of San Diego, California to perform the trenching. Firm Name subcontracted American Scientific Laboratories, LLC (ASL) of Los Angeles, California to perform the chemical analyses of the sediment samples. Firm Name’s soil testing laboratory in Irvine, California performed the geotechnical testing of the sediment samples.

5.0 FIELD ACTIVITIES

Field activities performed by Firm Name during the sediment sampling program included overseeing the trenching, preparing daily field logs, lithologic logging, and photographing of the trenches, and collecting and documenting geotechnical and chemical samples. The Site field activities were conducted on April 19 through 21, 2017. All field activities were completed in general accordance with the SAP.

5.1 FIELD SAMPLING

The field sampling program included collecting sediment samples for chemical and geotechnical testing in accordance with the SAP. Prior to field sampling, the USACE’s biologist performed a bird and bird nesting survey in compliance with the Clean Water Act (CWA) Section 404 Compliance Documentation, U. S. Army Corps of Engineers – Los Angeles District LA River Reach 5C Sediment Sampling January 2017” and “Record of Environmental Consideration” provided in the supporting documents in Attachment C. Bird nesting surveys were conducted prior to sampling each day. No Federally-listed avian species were observed by the USACE’s biologist during the field work. Woody vegetation within the Site was avoided per the instruction of the USACE’s biologist.

Best management practices employed during sampling as identified in the Record of Environmental Consideration, provided in the supporting documents in Attachment C of the SAP were followed during the implementation of the field activities, except as noted in Section

5.2.4 - Field Sampling Deviations.

5.2 SEDIMENT SAMPLING, COLLECTION LOCATIONS, AND DEVIATIONS

Sediment sampling, collection locations, and field sampling deviations are summarized in the sections below.

5.2.1 Composite Sediment Sampling for Chemical Analyses and Collection Locations

Twenty-five sample locations are identified on Figure 2. These locations were selected based on accessibility, absence of woody vegetation, thickness of sediment to be removed, and spatial distribution in the sampling area. Given similar accessibility and absence of woody vegetation, a priority was placed on locations interpreted to have thicker accumulation of sediments. Actual sampling locations were selected in the field based on logistical conditions and access available during field work. The prefix for these sediment samples was “LARR5C2017-##” for Location 2017. The coordinates, approximate channel floor elevations, and sampling elevations and depths for the sediment sample locations are provided in Table 1.

A backhoe equipped with rubber tires was used to excavate to the total depth of each exploratory trench. Sediments removed from the excavation were temporarily stockpiled adjacent to the excavation. During this process, sediment samples were collected from the backhoe bucket. A PID was used to field-screen sediments for volatile organic compounds (VOCs) at each sampling depth. Sampling depths ranged from 1 to 7.5 feet below ground surface (bgs) and are specified in Table 1. All trenches remained open to total depth and no water was encountered during sampling.

All samples were placed in containers in accordance with the directions of the laboratory. The sample containers were sealed to reduce the potential for cross-contamination. All the samples had their containers physically marked as to the sample location. Sediment samples were placed in precleaned containers and stored immediately in coolers chilled to 4 degrees Celsius (o C). Chain-of-custody procedures were followed and documented. The laboratory formed 27 composite samples using the 50 primary and four duplicate sediment samples in accordance with Firm Name’s compositing instructions (Table 2).

After sampling of a trench was completed, the trench was backfilled with the excavated material. This material was placed back into the excavation by the backhoe but was not compacted.

Documentation of the sample locations was accomplished using a Trimble global positioning system (GPS) system with a positioning accuracy of approximately 3 feet. The locations were recorded in Geographic coordinates (North American Datum 1983 [NAD 83] latitude/ longitude) and are listed in Table 1.

5.2.2 Targeted Sediment Sample for Chemical Analyses

The SAP specified that targeted samples would be collected to evaluate sediments found to exhibit field evidence of potential contamination, such as discoloration or elevated PID readings. Sediment from a depth of 1 foot bgs at trench location X exhibited a PID reading of 10 parts per million (ppm) and slight discoloration. A targeted sample (LARR5C2017-X1) of this soil was collected.

5.2.3 Discrete Sediment Samples for Geotechnical Testing

Three discrete sediment samples (LARR5C2017-F5, -P3.5 and -Y2) were collected and tested for selected geotechnical parameters to provide data to support evaluation of potential re-use or disposal alternatives.

5.2.4 Field Sampling Deviation

The SAP specified that sediments excavated from a trench would be placed on plastic sheeting near the trench. At the first trench location, plastic sheeting was utilized but the cobbly and irregular terrain made the plastic sheeting highly susceptible to tearing and becoming mixed with the sediments when backfilling the trench. To avoid the risk of inadvertently including plastic sheeting in backfilled trenches, sediments excavated from the other 24 trenches, which did not exhibit potential contamination though field observation, were temporarily stockpiled directly on the ground surface near the trenches before being placed back into the trenches. Trench X had sediment that exhibited slight discoloration and an elevated PID measurement relative to other sediment samples collected from the Site. This sediment was very limited in volume, and all of it was removed from the trench and placed in a sample container for analyses.

5.3 DOCUMENTATION AND LITHOLOGIC LOGGING

Documentation by Firm Name staff during the investigation activities included summarizing the daily field activities in a daily field log and photographing selected activities. Firm Name also photographed and prepared a field trench log for each trench location. Documentation was performed in general accordance with the SAP.

Photographs of the trenches are included in Appendix C.

In accordance with the SAP, sediments were logged by an Firm Name geologist using visual manual procedures of American Society for Testing of Materials (ASTM) Standard D2488-09a (ASTM, 2009) for guidance, which is based on the Unified Soil Classification System (USCS).

Firm Name recorded additional comments (e.g., descriptions of trash, if present) on the trench logs. Copies of the trench logs are provided in Appendix D. The trench logs also include information such as the equipment used for excavation, sampling depths, PID measurements, and depth of trench.

The lithology observed in the trenches consisted of boulders (diameter exceeding 12 inches);

cobbles (diameter greater than 3 inches and up to 12 inches); and materials with diameters of 3 inches or less including gravel, sand, and trace fines.

6.0 LABORATORY TESTING

The following subsections summarize the chemical and geotechnical testing completed for this investigation.

6.1 SAMPLES FOR CHEMICAL ANALYSES

Sediment samples collected from the trenches were composited by the analytical laboratory for chemical analyses in accordance with Firm Name proposed compositing instructions (Table 2). Each composite sample consist of two individual samples from similar depths (relative to ground surface) from two trenches near each other, where feasible. Compositing all 50 samples in groups of two resulted in 25 composited samples for laboratory analysis. Two of the composited samples were selected for duplicate analyses. In addition, one targeted sample was collected from sediments that exhibited slight discoloration and an elevated PID measurement relative to other sediment samples collected from the Site.

6.2 CHEMICAL TESTING AND DEVIATIONS

Chemical testing and deviations are summarized in the sections below.

6.2.1 Chemical Testing

ASL conducted chemical testing of the composite samples and targeted sediment sample as indicated in the SAP. Results of the chemical testing and chain-of-custody documentation are provided in Appendix E. The samples were analyzed for one or more of the following:

• total recoverable petroleum hydrocarbons (TRPH) using EPA Method 418.1;

• organochlorine pesticides using EPA Method 8081A;

• polychlorinated biphenyls (PCBs) using EPA Method 8082;

• pH using EPA Method 9045D;

• VOCs using EPA Method 8260B;

• polynuclear aromatic hydrocarbons (PAHs) using EPA Method 8270SIM;

• Title 22 metals using EPA Method 6010B/7471A;

• solubility in lead (STLC and/or TCLP) using EPA Method 6010B; and

• 96-hour Acute Aquatic Toxicity using the California Department of Fish and Game method/ California Department of Health Services (DOHS) (Title 22) Hazardous Waste Bioassay.

6.2.2 Analytical Program Deviations

Laboratory analysis for the soluble component for metals was not included in the proposed SOW. Results for total lead in some of the composite samples, however, indicated concentrations of total lead that exceeded 10 times the STLC and/or 20 times the TCLP for lead. Waste characterization for these levels of total lead requires additional analyses for the soluble component of lead. Consequently, soluble lead analyses were performed using the STLC method on seven composite samples and total and soluble lead analyses were performed on the 14 discrete sediment samples corresponding to those seven composite samples. Soluble lead results for several of these discrete sediment samples exceeded the STLC for lead. To provide a more representative data set for soluble lead, with USACE’s approval, the remaining discrete sediment samples collected during this investigation were analyzed for soluble lead using the STLC method.

6.3 GEOTECHNICAL TESTING AND DEVIATIONS

Geotechnical testing and deviations are summarized in the sections below.

6.3.1 Geotechnical Testing

Firm Name conducted geotechnical testing on three discrete sediment samples (LARR5C2017-F5, -P3.5 and -Y2) following guidelines in accordance to ASTM D3740:

Standard Practice for Minimum Requirements for Agencies Engaged in the Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction (ASTM, 2012).

Geotechnical testing included sieve (ASTM D6913) and hydrometer analyses (ASTM D422), and specific gravity (ASTM D854 and ASTM C127) and/or expansion index (ASTM D4829).

Results of the geotechnical testing and chain-of-custody documentation are provided in Appendix F.

6.3.2 Geotechnical Testing Deviations

Due to the predominantly coarse grained nature of the material sampled and the general similarity of the fines observed, the expansion index test was performed only on sample

LARR5C2017-F5.

7.0 RESULTS AND DATA EVALUATION

The following subsections provide a summary of the chemical analytical results, data quality review, chemical data evaluation, and geotechnical results for this investigation.

7.1 SUMMARY OF CHEMICAL ANALYTICAL RESULTS

The chemical results for composite, targeted, and discrete sediment samples collected from the Site are summarized in Tables 3 through 5. If applicable or available, sediment screening values are provided in the tables. Laboratory analytical reports and chain-of-custody documentation are presented in Appendix E. A summary of the sediment sample results is provided below.

• No VOCs were detected above the laboratory reporting limits, except for acetone in sample LARR5C2017-X1 (232 micrograms per kilogram [µg/kg]).

• TRPH was detected in all but two sediment samples, at concentrations ranging from

11.6 to 107J (estimated value) milligrams per kilogram (mg/kg).

• PCBs were not detected above the laboratory reporting limits in any of the sediment samples, except for Arcolor 1254 in duplicate composite sample LARR5C2017- DUP3_DUP4 (139J µg/kg).

• Organochlorine pesticides, including 4,4´-DDD, 4,4´-DDT, alpha-chlordane and/or gamma-chlordane, were detected above the laboratory reporting limits in 6 of 28 samples, at concentrations ranging from 2.17 to 20.6 µg/kg.

• PAHs, including anthracene, benzo(a) anthracene, chrysene, fluoranthene, indeno (1,2,3-cd) pyrene, phenanthrene and/or pyrene, were detected above the laboratory reporting limits in 21 of 28 sediment samples, at concentrations ranging from 5.00 to 186 µg/kg.

• pH results in sediment samples were generally neutral and ranged from 6.76 to 8.48 pH units.

• The metals arsenic, barium, cadmium, total chromium, cobalt, copper, lead, mercury, molybdenum, nickel, vanadium and zinc, were detected above their laboratory reporting limits in one or more sediment samples. The metals antimony, beryllium, selenium, silver and thallium were not detected above the reporting limit in any of the sediment samples collected.

• Total lead was the only metal that exceeded a threshold that required evaluation of the soluble component of the metal, which in the case of lead is 50 mg/kg or 10 times the STLC. Total lead concentrations in eleven sediment samples exceeded this threshold and ranged from 50.0 to 166 mg/kg.

• Soluble (STLC) lead was detected above the laboratory reporting limit in 53 of 61 sediment samples, at concentrations ranging from 0.506 to 9.37 milligrams per liter (mg/L).

• Soluble (TCLP) lead was not detected above the laboratory reporting limit in any of the six sediment samples analyzed using this method.

7.2 DATA QUALITY REVIEW OF CHEMICAL DATA

Firm Name and the analytical laboratory followed specific quality assurance/quality control (QA/QC) procedures to evaluate analytical data generated from the sediment samples (Appendix G). The laboratory quality control results indicate that the sampling and analyses performed in generating data presented in this report were generally consistent with the analytical methods. The results of the data quality review are reflected in the data summary tables. Where appropriate, soil data were qualified based on our review as recommended in the EPA National Functional Guidelines. The data, as qualified, are acceptable, and can be used for decision making purposes; however, the limitations identified by the applied qualifiers should be considered when using the data. Overall, the data generated during the investigation is suitable for use in determination of conditions at the site.

7.3 CHEMICAL DATA EVALUATION

When available, chemical results were compared to their respective EPA Region 9 RSLs for Chemical Contaminants at Superfund Sites (EPA, 2016), DTSC-SLs for residential and commercial/industrial soils (DTSC, 2016), and/or waste characterization criteria (STLC, TCLP and TTLC). Arsenic concentrations in sediment were compared to the DTSC Los Angeles County upper bound limits (DTSC, 2008), rather than the RSLs or DTSC-SLs. Consistent with DTSC screening level policy (DTSC, 2016), lead concentrations in sediment were compared to the DTSC LeadSpread 8 screening levels for residential and commercial/industrial land use (DTSC, 2011), rather than the RSLs.

Results of these comparisons are described in the sections below.

7.3.1 Regional Screening Levels

All chemical results were below the RSLs for residential and commercial/industrial soils, except for the following.

• In the one targeted sample (LARR5C2017-X1), indeno (1,2,3-cd) pyrene was detected at 162 µg/kg, which is above its RSL for residential soils but below its RSL for commercial/industrial soils (Table 3).

• Lead was detected at concentrations of 104 and 166 mg/kg in two composite samples (LARR5C2017-K4_L4 and LARR5C2017-O3.5_P3.5). These values are above the RSL for residential soils but below the RSL for commercial/industrial soils (Table 4).

Additional analyses of the four individual soil samples that comprised these composite samples (LARR5C2017-K4, LARR5C2017-L4, LARR5C2017-O3.5, and LARR5C2017-P3.5) indicated lead concentrations below the RSL for residential soils (Table 4).

7.3.2 Waste Characterization Criteria

Fifty-four discrete samples and seven composite samples were analyzed for soluble lead (STLC and/or TCLP). All results were below the STLC and TCLP for lead of 5 mg/L, except for the following (Table 5).

• Soluble (STLC) lead was detected at 9.37 mg/L in one composite sample

LARR5C2017-K4_L4.

• Soluble (STLC) lead was detected at 5.37, 7.18, and 8.49 mg/L in discrete samples LARR5C2017-W2, LARR5C2017-L4, and LARR5C2017-K4, respectively.

A statistical evaluation of the soluble (STLC) lead data was performed in accordance with SW-846. Based on the reported results, the number of samples analyzed was sufficient to support statistical comparison to the STLC for lead. ProUCL software (EPA, 2015. ProUCL Version 5.1.002 User Guide, October) was used to statistically evaluate the discrete lead STLC results. As listed in Table 5, the 95% UCL result of the mean was 2.26 mg/L for soluble (STLC) lead, which is below its STLC of 5 mg/L.

All composite sample results, including LARR5C2017-A2_U2, LARR5C2017-G4.5_H5, LARR5C2017-K4_L4, LARR5C2017-O3.5_P3.5 and LARR5C2017-X1, passed the DOHS (Title 22) Hazardous Waste Bioassay using Fathead Minnows.

7.4 GEOTECHNICAL RESULTS

As indicated in Section 5.3 of the report, material encountered in the exploratory trenches consisted of boulders, cobbles, gravel, sand, and trace fines. The geotechnical laboratory tests were performed only on the “finer”, i.e., smaller than 3 inches, portion of the materials encountered in the trenches. As such, the soil classification provided on the laboratory test results does not purport to represent the sediments as a whole. An all-encompassing gradation analysis that incorporates cobbles and boulders would involve several thousand pounds of material, require special equipment, and would need to be performed in the field.

Such endeavor was beyond Firm Name’s scope of services. The laboratory tests performed indicate that the soil matrix consists primarily of granular material ranging from poorly graded sand with silt and gravel to poorly graded gravel with sand. The percentage of fines (particles smaller than 0.075mm) varies between 2.5 and 7.3 with more silt than clay particles. The specific gravity of the soils tested varies between 2.65 and 2.69, and the material has no expansion potential, according to the ASTM test method.

The coarse nature of the material is apparent though review of the Photo Log (Appendix C) and Trench Logs (Appendix D). As estimated during filed logging, cobbles and boulders make up a substantial portion of the material and ranged from 55 to 90% (by volume) of the material excavated during sampling. The largest of the boulders exceeded approximately 3 feet in diameter and typical clast size was estimated as a large cobble on the order of 9 inches in diameter.

8.0 DISCUSSION OF DISPOSAL OPTIONS

With the exception of lead, chemical analyses indicate the soil has favorable chemical results for various disposal options. Lead concentrations exceeded residential RSLs in two composite samples but analyses of the individual samples making up these composite samples yielded results that were below the residential RSL for lead. Receiving facilities will evaluate the laboratory results and will decide how they will classify materials. They may accept the material as non-hazardous material for disposal or reuse if they consider the 95% UCL of 2.26 mg/L for soluble (STLC) lead as representative of the overall volume of sediment; however, they may also require additional testing, information on source of material, and/or implementation of a soil management plan during removal to provide observation and monitoring of the material as it is removed. The samples collected and tested consisted of interstitial sediments between the cobbles and boulders. Elevated lead concentrations likely are associated with the finer materials in the samples (clays, silts, and mixtures of clay, silt, and sand) and we expect would be less likely to be associated with the cobbles and boulders.

One potential approach for disposal of the material would involve segregating the material and sampling the coarse and fined grained fractions separately. If sample results are favorable for the coarse fraction, this material, which may represent 60 to 70% or more of the total volume and mass of the material, could be disposed of without needing to address questions related to the elevated concentrations of soluble (STLC) lead detected in some of the samples of finer-grained material. If the USACE pursues this option, additional sampling and analyses should be done to confirm the viability of this approach.

Another potential issue for reuse is the coarseness of the material. That is, receiving facilities may require oversize materials to be crushed prior to use as backfill (e.g., materials greater than 10 inches). The receiving facility may offer to do this at a cost or require that it be done prior to receipt of the material.

The detection of elevated soluble lead above its STLC in some samples complicates the identification of disposal options for the sediment. Firm Name provided the summary analytical tables and statistical evaluations to two waste management contractors (American Integrated Services and IOEI) with experience in characterization, transportation, and disposal of soils, sediments, and other waste materials, to obtain their input on potential options for disposal of the sediment. American Integrated Services did not respond. A rough order of magnitude cost estimate from IOEI is provided in Appendix H. The general scope of work described by IOEI is as follows:

• Conduct additional sampling and analyses at a rate of one sample per 500 cubic yards, with analysis for TPH, VOCs, and metals, to confirm the viability of the subsequent steps.

• Remove soils at three locations where soil exceeded hazardous levels for soluble lead (sample locations LARR5C2017-W2, LARR5C2017-L4, and LARR5C2017-K4) as “hot spot removal” and dispose of this material (estimated 1,000 tons) as non-hazardous restricted waste at the Waste Management Facility in Simi Valley.

• Segregate materials by screening out clasts larger than 3-inches or 6-inches in diameter, resulting in an estimated 49,000 tons of cobbles and boulders and 25,000 tons of sub-cobble materials.

• Dispose of the cobbles and boulders as nonhazardous waste at the Waste Management Facility in Azusa, California.

• Dispose of sub-cobble material as non-hazardous special waste at the Waste Management Facility in Azusa, California.

In addition, Firm Name contacted Vulcan Materials to obtain its requirements for import of fill to its Durbin Landfill in Irwindale, California. A copy of the forms that would be used to submit information for consideration by Vulcan Materials is provided in Appendix H. For acceptance at this facility, soil or sediment must not contain any constituents with soluble concentrations that exceed drinking water standards; this criterion would preclude disposal at the Vulcan Materials facility of the materials tested for this project. Disposal at this facility might, however, be feasible for the coarse materials if they are segregated and tested separately as described above. IOEI also indicated that the cobbles and boulders may have additional disposal or reuse options for removal at a reduced cost, but these materials would need to be segregated and tested independently.

Finally, we recommend using the findings from this report to solicit bids for disposal from contractors who specialize in soils impacted with lead (e.g., contractors that work on Caltrans projects) to obtain additional information on options and estimated costs for soil disposal/reuse.

9.0 SUMMARY AND CONCLUSIONS

Firm Name collected and analyzed sediment samples for chemical and geotechnical testing from 25 exploratory trenches within Reach 5C of the Los Angeles River channel to provide data for use in identifying and evaluating potential offsite disposal/reuse options. All field activities were conducted in general accordance with the SAP. Although some samples exceeded the RSLs for residential soils and STLC for lead, none of the samples exceeded the RSLs for commercial/industrial soils and the 95% UCL of the mean for soluble (STLC) lead is below the STLC of 5 mg/L for lead. Subject to approval by an appropriate regulatory agency and disposal facility, it likely will be feasible to handle and transport the sediments as non-hazardous waste provided the entire volume of sediment is considered together. However, each receiving facility establishes its own acceptance criteria and must meet specific regulatory permit conditions, and may require additional testing, source history of the material, and/or monitoring during excavation. Options for reuse may be limited based on the lead concentrations. The occurrence of elevated lead is likely associated with the finer fraction of sediments (silt, clay, and silty sand/clayey sand mixtures). Segregation of the fines and coarse materials and resampling might eliminate lead as a constituent of concern in the coarse fraction. Another consideration for the coarse material is that some of this material exceeds diameters desirable for backfill and may need to be crushed for this use.

Preliminary inquiries into disposal options have identified a potential path for disposal of the material. This path includes segregation of specific areas for specific disposal as restricted non-hazardous waste based on lead concentrations (tentatively identified as three locations but subject to change based on additional sampling and analyses), segregation of the material into cobbles and boulders and sub-cobbles, additional analyses for confirmation of selected constituents, and disposal of the material as non-hazardous waste. This report may be used to solicit additional soil disposal/ reuse options from contractors that specialize in soil waste disposal.

10.0 REFERENCES

Firm Name (Firm Name), 2017, Sampling and Analysis Plan, Location Sediment Sampling and Analysis, Los Angeles, California, April 4.

American Society for Testing of Materials (ASTM), 2009, Standard Practice for Description and Identification of Soils (Visual-Manual Procedure), July.

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DTSC, 2011, User’s Guide to LeadSpread 8 and Recommendations for Evaluation of Lead Exposures in Adults, September.

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EPA, 2016, Regional Screening Levels for Chemical Contaminants at Superfund Sites, Region 9, <http://www.epa.gov/region9/superfund/prg/>, May.

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http://dtsc.ca.gov/upload/Background-Arsenic.pdf