Sub-Appendix D-A. Technical Memorandum Cover Soil Sampling, Sanitation Districts, August 2008

Transcription

1 Sub-Appendix D-A Technical Memorandum Cover Soil Sampling, Sanitation Districts, August 2008

2 Technical Memorandum Cover Soil Sampling Palos Verdes Landfill Torrance, California Prepared by: County Sanitation Districts of Los Angeles County 1955 Workman Mill Road Whittier, California August 2008

3 Technical Memorandum Cover Soil Sampling at Palos Verdes Landfill TABLE OF CONTENTS 1.0 INTRODUCTION SITE BACKGROUND DETERMINATION OF ARSENIC BACKGROUND CONCENTRATION SOIL SAMPLING PROCEDURES SUMMARY OF ANALYTICAL RESULTS DISCUSSION CONCLUSION REFERENCES... 6 LIST OF FIGURES Figure 1 Figure 2 Figure 3 Remedial Investigation Soil Sampling Locations 2004 Soil Cover Sampling Locations 2008 Soil Cover Sampling Locations LIST OF TABLES Table 1 Table 2 Summary of Soil Sampling Results, Palos Verdes Landfill 2008 Analytical Results of Cover Soil Samples, Palos Verdes Landfill LIST OF APPENDICES Appendix A Appendix B Background Cover Soil Calculations, Nexus Environmental Services Laboratory Reports

4 Technical Memorandum Cover Soil Sampling at Palos Verdes Landfill 1.0 INTRODUCTION This Technical Memorandum presents analytical results of recent surface soil samples collected at the Palos Verdes Landfill (Site) to further evaluate background concentrations of arsenic that were detected in previous sampling events at the landfill. Original cover soil sampling was conducted during the Remedial Investigation (RI) (Sanitation Districts, 1995). Sampling described herein was requested by the California Department of Toxic Substances Control (DTSC) to confirm previous arsenic detections obtained during the RI, assess the lateral extent of any confirmed detections, and re-evaluate background levels within the cover soil for the Five- Year Review process. 2.0 SITE BACKGROUND Landfilling operations began in 1952, conducted by a private operator (Ben K. Kazarian and Sons later to become BKK). The County Sanitation Districts of Los Angeles County (Sanitation Districts) acquired the facility in 1957 and continued operations through The Site was previously operated as a diatomite mine by other parties not associated with the Sanitation Districts. In December 1980, the landfill ceased accepting waste because the design capacity of the landfill had been reached. A small portion of the waste (approximately 3 to 4 percent) that was accepted was hazardous. Final cover soils were placed over completed portions of the landfill at various stages of development. All areas of the landfill are covered with a layer of soil, which is regularly inspected and maintained. The source of cover soils at the Site is a combination of native onsite soils 1 and imported soils from offsite. As normal landfill settlement occurs, any depressions are filled with additional soil to prevent ponding of water over the landfill. During the RI, arsenic was analyzed in 56 soil samples that were collected from final cover materials (SC-1 through SC-56, see Figure 1). These sample locations were randomly selected and located across the entire landfill footprint. Sample locations included various areas of the Site including heavily used areas such as the equestrian center, the horse trail, and the South Coast Botanic Garden s lake and stream area. Arsenic concentrations in these samples ranged from 0.47 to 27.9 milligrams per kilogram (mg/kg) (Sanitation Districts, 1995). Arsenic concentrations detected in the final cover soils where within the range of background arsenic concentrations established in the RI. This is based on the analysis of 53 offsite background soil and rock formation samples, unaffected by the landfill, which were collected 1 In general, native onsite soils were obtained from alluvium and bedrock excavated at the Site. 1

5 Technical Memorandum Cover Soil Sampling at Palos Verdes Landfill and analyzed during the RI (see Figure 1). Detections of arsenic in the soil and rock formation samples ranged from 0.17 to 58 mg/kg (see Table 1). Therefore, in accordance with DTSC guidance at this time, the arsenic detections in the final cover soils were considered to be below or within background values evaluated during the RI. During the Five-Year Review, an additional 46 soil samples were collected from final cover materials at the Site (SC-57 through SC-102 as shown in Figures 2 and 3). Specifically, two cover soil investigations were performed during the Five-Year Review. The first, conducted in 2004, had two goals including (1) verification of PAH detections in one area of the landfill identified during the RI, and (2) assessment of recently imported soil to address concerns raised by the Palos Verdes Landfill Citizens Advisory Board (CAB). The second investigation was conducted in 2008 at the request of DTSC to verify detections and lateral extent of arsenic in areas sampled during the RI.. Pursuant to DTSC s request, the Sanitation Districts re-evaluated the arsenic detections in cover soils based on guidelines developed for evaluating background levels and cleanup guidelines for arsenic in soils at Los Angeles Unified School District School Sites (DTSC, 2007). This methodology has been specifically designed to address the background arsenic concentrations at schools sites and the methodology is more stringent than what has been applied at the Site during the RI. Nevertheless, DTSC requested that the Sanitation Districts follow this method to estimate background concentration for arsenic at the Site. 3.0 DETERMINATION OF ARSENIC BACKGROUND CONCENTRATION The method used to estimate background arsenic concentrations in the cover soil at the Site followed Cleanup Goals for Proposed and Existing School Sites (DTSC, 2007). This conservative method applies graphical and statistical methods based on a dataset of arsenic concentrations in soil to arrive at an estimated background concentration. Nexus Environmental Services (Nexus) was retained by the Sanitation Districts to estimate the background concentration of arsenic in final cover soils at the Site using DTSC s Cleanup Goals for Proposed and Existing School Sites methodology. Nexus initially tested the background data set (i.e., the 53 offsite background samples obtained during the RI) for outliers; these are values which appear to be statistically greater then the remainder of the data set. Based on this outlier analysis a single analytical result, sample RFB-22 at 58 mg/kg, was removed from further consideration as background. The remaining detections of arsenic in the soil and rock formation sampled in the RI ranged from 0.17 to 18 mg/kg. Next, Nexus created normal and lognormal 2

6 Technical Memorandum Cover Soil Sampling at Palos Verdes Landfill plots of the arsenic background concentrations minus the outlier value. The results of the calculations by Nexus are presented in Appendix A. Based on this analysis, an apparent background arsenic concentration of 12 mg/kg was identified. This validated background concentration will be utilized for the Palos Verdes Landfill Five-Year Review process. Of the 56 cover soil samples collected during the RI, six soil samples (SC-10, SC-26, SC-27, SC- 38, SC-43 and SC-45) contained concentrations of arsenic greater than 12 mg/kg (see Figure 1). At the request of DTSC, the Sanitation Districts conducted a sampling program at these locations to confirm and establish the lateral extent of these detections. 4.0 SOIL SAMPLING PROCEDURES Soil cover samples obtained during 2004 and 2008 were collected in accordance with a work plan that was approved by DTSC for the Five-Year Review. The work plan was prepared by Todd Engineers and Risk-Based Decisions, Inc (2004) and revised in August 2004 based on comments received from DTSC. During the 2004 investigation, soil samples were collected on October 26, 2004 following the protocols described below. During the 2008 investigation, samples were collected on February 21, March 20, and April 8, On February 21, 2008, locations of RI soil samples (SC-10, SC-26, SC-27, SC-38, SC-43, and SC-45) were determined in the field. They were determined by overlaying a current topographic map upon the soil sample location map contained in the RI Report. Coordinates for the RI sample locations were obtained from the topographic map and subsequently located in the field using a hand-held GPS unit. Sanitation Districts staff collected three soil cover samples at each RI sampling location for a total of twenty-seven soil samples (SC-76 through SC-102). Soil sample locations are shown in Figure 3. The soil cover samples were located at a distance of 5 feet, in a radial pattern, from the original RI sampling location. A field log notebook was kept during each soil sampling event, documenting field sampling activities, measurements, and environmental conditions. Evidence of odors and visual indications of contamination at the sampling locations were documented in the field notebook. No visual indications of contamination were observed and no odors were detected during the recent soil cover sampling investigations. Relatively undisturbed shallow soil samples were collected using a hand-driven core sampler. The core sampler was lined with a stainless steel liner. Prior to taking the samples, surficial materials including grass and plant material, wood chips, and other extraneous material were 3

7 Technical Memorandum Cover Soil Sampling at Palos Verdes Landfill removed from each sampling site. The core sampler and sample liner were hammered into the ground to a depth approximately 6 to 18 inches below ground surface (bgs). Once the intended depth was reached, the core sampler was twisted to shear the sampler off the bottom of the core hole. The core sampler was removed from the ground and the lower sample liner was removed from the sampler. The ends of the sample liner were sealed with Teflon film, capped with plastic caps, and sealed with electrical tape. The tubes were labeled with the site name, sample number, sample depth, sampler, and sample date. Soil samples were stored in an ice chest and transported Weck Laboratories, Inc. in City of Industry, California for analyses. Weck Laboratories is a California certified laboratory. To establish the documentation necessary to trace sample possession, a chain of custody form was used. Every sample collected for analysis was logged on this form along with the requested analyses, time and data of sample collection, and sample media. The chain of custody form accompanied the sample throughout the custody process. Prior to sampling at each location, all sampling equipment was washed in a solution of Alconox and distilled water and rinsed in two separate distilled water baths. Duplicate samples were collected at sample location SC-73 and SC-93. Duplicate samples were collected immediately adjacent to SC-73 and SC-93. Soil was removed from each of the lower two liners, placed together in a stainless steel container, and mixed with a stainless steel spoon to homogenize or composite the samples. Then the mixed samples were placed back into the liners and sealed and labeled. 5.0 SUMMARY OF ANALYTICAL RESULTS The cover soil samples were analytically tested for arsenic using U.S. EPA Method 6010B. Table 1 provides a summary of all cover soil results obtained from the Site, while Table 2 presents a summary of the 2008 results. Included in Table 2 is the concentration of arsenic at the six original RI sampling locations (SC-10, SC-26, SC-27, SC-38, SC-43 and SC-45). Copies of analytical reports are included in Appendix B. Based on the 2008 analytical results, arsenic detections in the cover soils ranged from less than 2.7 to 26 mg/kg. Except for RI sample location area around SC-45, average arsenic concentrations were consistent with or below DTSC s Cleanup Goals for Proposed and Existing School Sites (see Table 2). However, at location SC-45, average arsenic detections were slightly greater than this very conservative background level. Therefore, an attempt was made to better characterize and arsenic detections in this area. On March 20, 2008 and on April 8, 2008, nine additional soil samples (SC-94 through SC-102) were collected and analyzed. Three rows of 4

8 Technical Memorandum Cover Soil Sampling at Palos Verdes Landfill samples spaced approximately 5 feet apart were located west of SC-82. Detections from these samples ranged from less than 2.7 to 19 mg/kg. 6.0 DISCUSSION As described in the RI Report, cover soils were placed at various stages of landfill development using onsite and imported materials. Arsenic has been documented in soil and rock formations in the general vicinity of the Site at concentrations ranging from 0.17 to 58 mg/kg (Sanitation Districts, 1995). Arsenic concentrations within the final soil cover at the landfill were evaluated during the RI. As described in the RI Report, concentrations of arsenic present in the final cover soils are within the range of arsenic concentrations that can be found naturally occurring in the vicinity of the Site. Therefore, the arsenic concentrations present in the final soil cover were considered background during the RI. Nevertheless, DTSC, for this Five-Year Review, requested the Sanitation Districts re-evaluate arsenic detections in cover soils based on more recent guidelines developed to evaluate the background levels and cleanup guidelines for arsenic in soils at Los Angeles Unified School District School Sites (DTSC, 2007). Due to the heterogeneous alluvial and bedrock materials utilized for soil cover, this school methodology is not directly applicable to this Site. Using this methodology a background arsenic concentration of 12 mg/kg was calculated for the Site with a range of valid background detections from 0.17 to 18 mg/kg. Except for the area immediately surrounding SC-45 at the Botanic Garden, average arsenic concentrations were consistent with or below DTSC s Cleanup Goals for Proposed and Existing School Sites. At location SC-45, average arsenic detections were slightly greater than this very conservative school site background level but within the range of valid detected background in the surrounding area. The average arsenic concentration from these soil samples obtained in the Botanic Garden (SC-82 through SC-84 and SC-95 through SC-102) is 13.3 mg/kg 2. Average arsenic concentration for all samples obtained from the Botanic Garden is 9.8 mg/kg (see Table 1). The variation in background concentrations is consistent with naturally occurring heterogeneous soils associated with fill materials and the geologic units from which it was obtained. Moreover, detections are at or below valid background soil values established for surrounding soil and rock formations. 2 One-half of the detection limit for soil sample SC-102 was assumed when averaging arsenic concentrations. 5

9 Technical Memorandum Cover Soil Sampling at Palos Verdes Landfill 7.0 CONCLUSION Background arsenic concentrations for the Site were re-evaluated using DTSC s Cleanup Goals for Proposed and Existing School Sites methodology (DTSC, 2007). Analytical results indicate that a heterogeneous composition of natural bedrock and alluvium was used to construct the final soil cover at the Site. Detections greater than the alternate school background level were isolated and not laterally extensive. With the exception of the SC-45 area, average cover soils at SC-10, SC-26, SC-27, SC-38 and SC-43 areas were within the alternate school background levels. Although the SC-45 area yielded average levels slightly higher than school background levels, these detections are well within the range of valid background levels for the Site. Accordingly, arsenic detections identified within the final soil cover at the Site are naturally occurring. 8.0 REFERENCES County Sanitation Districts of Los Angeles County, Remedial Investigation Report Palos Verdes Landfill; prepared for the Department Toxic Substances Control Cal/EPA, June Department of Toxic Substances Control, Arsenic Strategies, Determination of Arsenic Remediation, Development of Arsenic Cleanup Goals for Proposed and Existing School Sites, March, Todd Engineers and Risk-Based Decisions, Inc., Palos Verdes Landfill Five-Year Review Workplan Rolling Hills Estates, California, May,

10 Technical Memorandum Cover Soil Sampling at Palos Verdes Landfill Table 1 Summary of Soil Sampling Results a Palos Verdes Landfill Location No. Analyzed Range (mg/kg) b Average (mg/kg) b,c Main Site Ernie Howlett Park Botanic Garden Remedial Investigation Background Data Five-Year Review Background Data d Notes: a. Data from Remedial Investigation (Sanitation Districts, 1995) and 2004 and 2008 Cover Soil Sampling Investigations b. mg/kg - milligrams per kilogram c. Maximum values from duplicate samples were used to calculate average concentrations d. Using DTSC s Cleanup Goals for Proposed and Existing School Sites methodology, a single analytical result, sample RFB-22 at 58 mg/kg, was removed from the background data set used during the Remedial Investigation

11 Technical Memorandum Cover Soil Sampling at Palos Verdes Landfill Table Analytical Results of Cover Soil Samples Palos Verdes Landfill RI Sample ID (Arsenic Concentration) Laboratory ID Sample ID Date Arsenic Concentration (mg/kg) a Average Concentration (mg/kg) b SC-10 (20 mg/kg) SJ02660 SC-76 2/21/ SJ02661 SC-77 2/21/ SJ02662 SC-78 2/21/ SC-38 (14.2 mg/kg) SJ02663 SC-79 2/21/ SJ02664 SC-80 2/21/08 14 SJ02665 SC-81 2/21/ SC-45 (14.1 mg/kg) SJ02666 SC-82 2/21/08 26 SJ02667 SC-83 2/21/08 10 SJ02668 SC-84 2/21/ SJ04736 SC-94 3/20/08 18 SJ04737 SC-95 3/20/ SJ04738 SC-96 3/20/08 15 SJ05709 SC-97 4/8/08 12 SJ05710 SC-98 4/8/08 18 SJ05711 SC-99 4/8/08 19 SJ06068 SC-100 4/8/08 18 SJ06069 SC-101 4/8/08 12 SJ06070 SC-102 4/8/08 ND (2.7) c 13.3 SC-43 (27.9 mg/kg) SJ02669 SC-85 2/21/ SJ02670 SC-86 2/21/ SJ02671 SC-87 2/21/ SC-26 (15 mg/kg) SJ02672 SC-88 2/21/08 11 SJ02673 SC-89 2/21/08 10 SJ02674 SC-90 2/21/ SC-27 (15 mg/kg) SJ02675 SC-91 2/21/ SJ02676 SC-92 2/21/ SJ02677 SC-93 2/21/ SJ02678 SC-93D d 2/21/ e Notes: a. mg/kg = milligrams per kilogram b. Data from SC-10, SC-26, SC-27, SC-38, SC-43 and SC-45 not included in average c. ND = not detected above the detection limit in parentheses. One-half of the detection limit was assumed d. Duplicate sample of SC-93 e. The maximum value from the duplicate sample was used to calculate the average concentration

12 Technical Memorandum Cover Soil Sampling at Palos Verdes Landfill FIGURES

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16 Technical Memorandum Cover Soil Sampling at Palos Verdes Landfill APPENDIX A BACKGROUND COVER SOIL CALCULATIONS NEXUS EVIRONMENTAL SERVICES

17 Offsite Background Arsenic Data arsenic Log-Transf Outliers Removed Source: County Sanitation Districts of Los Angeles County, Remedial Investigation Report Palos Verdes Landfill, June 1995 Table 3-5.1

18 Test Arsenic Background Concentrations Normal Data Set Variable RI Onsite Soils Results Performed by Chris Stoker Date 22 January 2008 Frequency n 53 Mean % CI to Variance SD SE CV 171% Median % CI to Range IQR Percentile 2.5th th th th th Normal Quantile arsenic Coefficient p Shapiro-Wilk < Skewness < Kurtosis < Normality Plot Fit Graphic Inflection No Page 2 of 4

19 Test Arsenic Background Concentrations Log-Transformed Data Set Variable RI Onsite Soils Results Performed by Chris Stoker Date 22 January 2008 Frequency n 53 Mean % CI to Variance SD SE CV 150% Median % CI to Range IQR Percentile 2.5th th th th th Normal Quantile Coefficient p Shapiro-Wilk Skewness Kurtosis Lognormality Plot Fit Yes Graphic Inflection mg/kg arsenic - R Page 3 of 4

20 Test Arsenic Background Concentrations Log-Transformed Data Set (Outliers Removed) Variable RI Onsite Soils Results Performed by Chris Stoker Date 22 January 2008 Frequency n 52 Mean % CI to Variance SD SE CV 153% Median % CI to Range IQR Percentile 2.5th th th th th Normal Quantile Coefficient p Shapiro-Wilk Skewness Kurtosis Outliers Removed Lognormality Plot Fit Yes Graphic Inflection mg/kg Page 4 of 4

21 Technical Memorandum Cover Soil Sampling at Palos Verdes Landfill APPENDIX B LABORATORY REPORTS

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98 Report Date: Friday, February 29, 2008 Received Date: Friday, February 22, 2008 Received Time: 2:30 pm Turnaround Time: 5 days Client: San Jose Creek Water Quality Laboratory 1965 S. Workman Mill Road Whittier, CA Phone: (562) FAX: (562) Attn: Lavern Tamoria Project: SJ02660-SJ02678 Certificate of Analysis P.O.#: Work Order No: Sample ID: SJ02660 Matrix: Solid Sampled by: CM Sampled: 02/21/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 02/25/08 02/29/08 jba W8B0930 % Solids % by Weight Gravimetric 02/27/08 02/27/08 ppy W8B1028 Work Order No: Sample ID: SJ02661 Matrix: Solid Sampled by: CM Sampled: 02/21/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 02/25/08 02/29/08 jba W8B0930 % Solids % by Weight Gravimetric 02/27/08 02/27/08 ppy W8B1028 Work Order No: Sample ID: SJ02662 Matrix: Solid Sampled by: CM Sampled: 02/21/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 02/25/08 02/29/08 jba W8B0930 % Solids % by Weight Gravimetric 02/27/08 02/27/08 ppy W8B1028 Work Order No: Sample ID: SJ02663 Matrix: Solid Sampled by: CM Sampled: 02/21/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 02/25/08 02/29/08 jba W8B0930 % Solids % by Weight Gravimetric 02/27/08 02/27/08 ppy W8B1028 Work Order No: Sample ID: SJ02664 Matrix: Solid Sampled by: CM Sampled: 02/21/08 00:00 Sample Note: PVLF Analyte Result Qualifier Reporting Units Limit Dil Method Prepared Analyzed Batch Lab#: Page 1 of East Clark Avenue, City of Industry, California (626) FAX (626)

99 Certificate of Analysis Work Order No: Sample ID: SJ02664 Matrix: Solid Sampled by: CM Sampled: 02/21/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 02/25/08 02/29/08 jba W8B0930 % Solids % by Weight Gravimetric 02/27/08 02/27/08 ppy W8B1028 Work Order No: Sample ID: SJ02665 Matrix: Solid Sampled by: CM Sampled: 02/21/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 02/25/08 02/29/08 jba W8B0930 % Solids % by Weight Gravimetric 02/27/08 02/27/08 ppy W8B1028 Work Order No: Sample ID: SJ02666 Matrix: Solid Sampled by: CM Sampled: 02/21/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 02/25/08 02/29/08 jba W8B0930 % Solids % by Weight Gravimetric 02/27/08 02/27/08 ppy W8B1028 Work Order No: Sample ID: SJ02667 Matrix: Solid Sampled by: CM Sampled: 02/21/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 02/25/08 02/29/08 jba W8B0930 % Solids % by Weight Gravimetric 02/27/08 02/27/08 ppy W8B1028 Work Order No: Sample ID: SJ02668 Matrix: Solid Sampled by: CM Sampled: 02/21/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 02/25/08 02/29/08 jba W8B0930 % Solids % by Weight Gravimetric 02/27/08 02/27/08 ppy W8B1028 Work Order No: Sample ID: SJ02669 Matrix: Solid Sampled by: CM Sampled: 02/21/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 02/25/08 02/29/08 jba W8B0930 % Solids % by Weight Gravimetric 02/27/08 02/27/08 ppy W8B1028 Lab#: Page 2 of East Clark Avenue, City of Industry, California (626) FAX (626)

100 Certificate of Analysis Work Order No: Sample ID: SJ02670 Matrix: Solid Sampled by: CM Sampled: 02/21/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 02/25/08 02/29/08 jba W8B0930 % Solids % by Weight Gravimetric 02/27/08 02/27/08 ppy W8B1028 Work Order No: Sample ID: SJ02671 Matrix: Solid Sampled by: CM Sampled: 02/21/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 02/25/08 02/29/08 jba W8B0930 % Solids % by Weight Gravimetric 02/27/08 02/27/08 ppy W8B1028 Work Order No: Sample ID: SJ02672 Matrix: Solid Sampled by: CM Sampled: 02/21/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 02/25/08 02/29/08 jba W8B0930 % Solids % by Weight Gravimetric 02/27/08 02/27/08 ppy W8B1028 Work Order No: Sample ID: SJ02673 Matrix: Solid Sampled by: CM Sampled: 02/21/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 02/25/08 02/29/08 jba W8B0930 % Solids % by Weight Gravimetric 02/27/08 02/27/08 ppy W8B1028 Work Order No: Sample ID: SJ02674 Matrix: Solid Sampled by: CM Sampled: 02/21/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 02/25/08 02/29/08 jba W8B0930 % Solids % by Weight Gravimetric 02/27/08 02/27/08 ppy W8B1028 Work Order No: Sample ID: SJ02675 Matrix: Solid Sampled by: CM Sampled: 02/21/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 02/25/08 02/29/08 jba W8B0930 % Solids % by Weight Gravimetric 02/27/08 02/27/08 ppy W8B1028 Lab#: Page 3 of East Clark Avenue, City of Industry, California (626) FAX (626)

101 Certificate of Analysis Work Order No: Sample ID: SJ02676 Matrix: Solid Sampled by: CM Sampled: 02/21/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 02/25/08 02/29/08 jba W8B0930 % Solids % by Weight Gravimetric 02/27/08 02/27/08 ppy W8B1028 Work Order No: Sample ID: SJ02677 Matrix: Solid Sampled by: CM Sampled: 02/21/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 02/25/08 02/29/08 jba W8B0930 % Solids % by Weight Gravimetric 02/27/08 02/27/08 ppy W8B1028 Work Order No: Sample ID: SJ02678 Matrix: Solid Sampled by: CM Sampled: 02/21/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 02/25/08 02/29/08 jba W8B0930 % Solids % by Weight Gravimetric 02/27/08 02/27/08 ppy W8B1028 Lab#: Page 4 of East Clark Avenue, City of Industry, California (626) FAX (626)

102 Certificate of Analysis Weck Laboratories, Inc Conventional Chemistry/Physical Parameters by APHA/EPA/ASTM Methods - Quality Control Analyte Sample Result QC Result Qualifier Units Spike Level %REC %REC Limits RPD RPD Limit Batch W8B *** DEFAULT PREP *** Duplicate (W8B1028-DUP1) Source: Prepared & Analyzed: 02/27/08 % Solids % by Weight Weck Laboratories, Inc Metals (Non-Aqueous) by EPA 6000/7000 Series Methods - Quality Control Analyte Sample Result QC Result Qualifier Units Spike Level %REC %REC Limits RPD RPD Limit Batch W8B EPA 3050B Blank (W8B0930-BLK1) Prepared: 02/25/08 Analyzed: 02/29/08 Total Arsenic... ND mg/kg wet LCS (W8B0930-BS1) Prepared: 02/25/08 Analyzed: 02/29/08 Total Arsenic mg/kg wet LCS Dup (W8B0930-BSD1) Prepared: 02/25/08 Analyzed: 02/29/08 Total Arsenic mg/kg wet Matrix Spike (W8B0930-MS1) Source: Prepared: 02/25/08 Analyzed: 02/29/08 Total Arsenic mg/kg dry Matrix Spike Dup (W8B0930-MSD1) Source: Prepared: 02/25/08 Analyzed: 02/29/08 Total Arsenic mg/kg dry Lab#: Page 5 of East Clark Avenue, City of Industry, California (626) FAX (626)

103 Certificate of Analysis Contact: Hai Van Nguyen Authorized Signature (Project Manager) ELAP # 1132 LACSD # NELAC # 04229CA The results in this report apply to the samples analyzed in accordance with the chain of custody document. Weck Laboratories certifies that the test results meet all requirements of NELAC unless noted in the Case Narrative. This analytical report must be reproduced in its entirety. Notes: The Chain of Custody document is part of the analytical report. Any remaining sample(s) for testing will be disposed of one month from the final report date unless other arrangements are made in advance. All results are expressed on wet weight basis unless otherwise specified. ND = NOT DETECTED at or above the Reporting Limit. If J-value reported, then NOT DETECTED at or above the Method Detection Limit (MDL). Sub = Subcontracted analysis, original report enclosed. Dil = Dilution Factor MDL = Method Detection Limit MDA = Minimum Detectable Activity An Absence of Total Coliform meets the drinking water standards as established by the State of California Department of Health Services. The Reporting Limit (RL) is referenced as laboratory's Practical Quantitation Limit (PQL). For Potable water analysis, the Reporting Limit (RL) is referenced as Detection Limit for reporting purposes (DLRs) defined by EPA. If sample collected by Weck Laboratories, sampled in accordance to lab SOP MIS002 Flags for Data Qualifiers: Lab#: Page 6 of East Clark Avenue, City of Industry, California (626) FAX (626)

104 Report Date: Wednesday, April 2, 2008 Received Date: Friday, March 21, 2008 Received Time: 2:00 pm Turnaround Time: Normal Client: San Jose Creek Water Quality Laboratory 1965 S. Workman Mill Road Whittier, CA Phone: (562) FAX: (562) Attn: Lavern Tamoria Project: SJ04736-SJ04738 Certificate of Analysis P.O.#: 1037 Work Order No: Sample ID: SJ04736 Matrix: Solid Sampled by: CM Sampled: 03/20/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 03/26/08 04/01/08 jba W8C1039 % Solids % by Weight Gravimetric 04/02/08 04/02/08 ppy W8D0066 Work Order No: Sample ID: SJ04737 Matrix: Solid Sampled by: CM Sampled: 03/20/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 03/26/08 04/01/08 jba W8C1039 % Solids % by Weight Gravimetric 04/02/08 04/02/08 ppy W8D0066 Work Order No: Sample ID: SJ04738 Matrix: Solid Sampled by: CM Sampled: 03/20/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 03/26/08 04/01/08 jba W8C1039 % Solids % by Weight Gravimetric 04/02/08 04/02/08 ppy W8D0066 Lab#: Page 1 of East Clark Avenue, City of Industry, California (626) FAX (626)

105 Certificate of Analysis Weck Laboratories, Inc Conventional Chemistry/Physical Parameters by APHA/EPA/ASTM Methods - Quality Control Analyte Sample Result QC Result Qualifier Units Spike Level %REC %REC Limits RPD RPD Limit Batch W8D *** DEFAULT PREP *** Duplicate (W8D0066-DUP1) Source: Prepared & Analyzed: 04/02/08 % Solids % by Weight Weck Laboratories, Inc Metals (Non-Aqueous) by EPA 6000/7000 Series Methods - Quality Control 1 20 Analyte Sample Result QC Result Qualifier Units Spike Level %REC %REC Limits RPD RPD Limit Batch W8C EPA 3050B Blank (W8C1039-BLK1) Prepared: 03/26/08 Analyzed: 04/01/08 Total Arsenic... ND mg/kg wet LCS (W8C1039-BS1) Prepared: 03/26/08 Analyzed: 04/01/08 Total Arsenic mg/kg wet LCS Dup (W8C1039-BSD1) Prepared: 03/26/08 Analyzed: 04/01/08 Total Arsenic mg/kg wet Matrix Spike (W8C1039-MS1) Source: Prepared: 03/26/08 Analyzed: 04/01/08 Total Arsenic mg/kg dry Matrix Spike Dup (W8C1039-MSD1) Source: Prepared: 03/26/08 Analyzed: 04/01/08 Total Arsenic mg/kg dry Lab#: Page 2 of East Clark Avenue, City of Industry, California (626) FAX (626)

106 Certificate of Analysis Contact: Hai Van Nguyen Authorized Signature (Project Manager) ELAP # 1132 LACSD # NELAC # 04229CA The results in this report apply to the samples analyzed in accordance with the chain of custody document. Weck Laboratories certifies that the test results meet all requirements of NELAC unless noted in the Case Narrative. This analytical report must be reproduced in its entirety. Notes: The Chain of Custody document is part of the analytical report. Any remaining sample(s) for testing will be disposed of one month from the final report date unless other arrangements are made in advance. All results are expressed on wet weight basis unless otherwise specified. ND = NOT DETECTED at or above the Reporting Limit. If J-value reported, then NOT DETECTED at or above the Method Detection Limit (MDL). Sub = Subcontracted analysis, original report enclosed. Dil = Dilution Factor MDL = Method Detection Limit MDA = Minimum Detectable Activity An Absence of Total Coliform meets the drinking water standards as established by the State of California Department of Health Services. The Reporting Limit (RL) is referenced as laboratory's Practical Quantitation Limit (PQL). For Potable water analysis, the Reporting Limit (RL) is referenced as Detection Limit for reporting purposes (DLRs) defined by EPA. If sample collected by Weck Laboratories, sampled in accordance to lab SOP MIS002 Flags for Data Qualifiers: Lab#: Page 3 of East Clark Avenue, City of Industry, California (626) FAX (626)

107 Report Date: Wednesday, April 2, 2008 Received Date: Friday, March 21, 2008 Received Time: 2:00 pm Turnaround Time: Normal Client: San Jose Creek Water Quality Laboratory 1965 S. Workman Mill Road Whittier, CA Phone: (562) FAX: (562) Attn: Lavern Tamoria Project: SJ04736-SJ04738 Certificate of Analysis P.O.#: 1037 Work Order No: Sample ID: SJ04736 Matrix: Solid Sampled by: CM Sampled: 03/20/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 03/26/08 04/01/08 jba W8C1039 % Solids % by Weight Gravimetric 04/02/08 04/02/08 ppy W8D0066 Work Order No: Sample ID: SJ04737 Matrix: Solid Sampled by: CM Sampled: 03/20/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 03/26/08 04/01/08 jba W8C1039 % Solids % by Weight Gravimetric 04/02/08 04/02/08 ppy W8D0066 Work Order No: Sample ID: SJ04738 Matrix: Solid Sampled by: CM Sampled: 03/20/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 03/26/08 04/01/08 jba W8C1039 % Solids % by Weight Gravimetric 04/02/08 04/02/08 ppy W8D0066 Lab#: Page 1 of East Clark Avenue, City of Industry, California (626) FAX (626)

108 Certificate of Analysis Weck Laboratories, Inc Conventional Chemistry/Physical Parameters by APHA/EPA/ASTM Methods - Quality Control Analyte Sample Result QC Result Qualifier Units Spike Level %REC %REC Limits RPD RPD Limit Batch W8D *** DEFAULT PREP *** Duplicate (W8D0066-DUP1) Source: Prepared & Analyzed: 04/02/08 % Solids % by Weight Weck Laboratories, Inc Metals (Non-Aqueous) by EPA 6000/7000 Series Methods - Quality Control 1 20 Analyte Sample Result QC Result Qualifier Units Spike Level %REC %REC Limits RPD RPD Limit Batch W8C EPA 3050B Blank (W8C1039-BLK1) Prepared: 03/26/08 Analyzed: 04/01/08 Total Arsenic... ND mg/kg wet LCS (W8C1039-BS1) Prepared: 03/26/08 Analyzed: 04/01/08 Total Arsenic mg/kg wet LCS Dup (W8C1039-BSD1) Prepared: 03/26/08 Analyzed: 04/01/08 Total Arsenic mg/kg wet Matrix Spike (W8C1039-MS1) Source: Prepared: 03/26/08 Analyzed: 04/01/08 Total Arsenic mg/kg dry Matrix Spike Dup (W8C1039-MSD1) Source: Prepared: 03/26/08 Analyzed: 04/01/08 Total Arsenic mg/kg dry Lab#: Page 2 of East Clark Avenue, City of Industry, California (626) FAX (626)

109 Certificate of Analysis Contact: Hai Van Nguyen Authorized Signature (Project Manager) ELAP # 1132 LACSD # NELAC # 04229CA The results in this report apply to the samples analyzed in accordance with the chain of custody document. Weck Laboratories certifies that the test results meet all requirements of NELAC unless noted in the Case Narrative. This analytical report must be reproduced in its entirety. Notes: The Chain of Custody document is part of the analytical report. Any remaining sample(s) for testing will be disposed of one month from the final report date unless other arrangements are made in advance. All results are expressed on wet weight basis unless otherwise specified. ND = NOT DETECTED at or above the Reporting Limit. If J-value reported, then NOT DETECTED at or above the Method Detection Limit (MDL). Sub = Subcontracted analysis, original report enclosed. Dil = Dilution Factor MDL = Method Detection Limit MDA = Minimum Detectable Activity An Absence of Total Coliform meets the drinking water standards as established by the State of California Department of Health Services. The Reporting Limit (RL) is referenced as laboratory's Practical Quantitation Limit (PQL). For Potable water analysis, the Reporting Limit (RL) is referenced as Detection Limit for reporting purposes (DLRs) defined by EPA. If sample collected by Weck Laboratories, sampled in accordance to lab SOP MIS002 Flags for Data Qualifiers: Lab#: Page 3 of East Clark Avenue, City of Industry, California (626) FAX (626)

110 Report Date: Wednesday, April 23, 2008 Received Date: Wednesday, April 16, 2008 Received Time: 1:40 pm Turnaround Time: 5 days Client: San Jose Creek Water Quality Laboratory 1965 S. Workman Mill Road Whittier, CA Phone: (562) FAX: (562) Attn: Lavern Tamoria Project: SJ06068-SJ06070 Certificate of Analysis P.O.#: Work Order No: Sample ID: SJ06068 Matrix: Solid Sampled by: CM Sampled: 04/08/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 04/17/08 04/22/08 jba W8D0652 % Solids % by Weight Gravimetric 04/17/08 04/17/08 ppy W8D0654 Work Order No: Sample ID: SJ06069 Matrix: Solid Sampled by: CM Sampled: 04/08/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic mg/kg dry EPA 6010B 04/17/08 04/22/08 jba W8D0652 % Solids % by Weight Gravimetric 04/17/08 04/17/08 ppy W8D0654 Work Order No: Sample ID: SJ06070 Matrix: Solid Sampled by: CM Sampled: 04/08/08 00:00 Sample Note: PVLF Reporting Analyte Result Qualifier Units Limit Dil Method Prepared Analyzed Batch Total Arsenic... ND mg/kg dry EPA 6010B 04/17/08 04/22/08 jba W8D0652 % Solids % by Weight Gravimetric 04/17/08 04/17/08 ppy W8D0654 Lab#: Page 1 of East Clark Avenue, City of Industry, California (626) FAX (626)

111 Certificate of Analysis Weck Laboratories, Inc Conventional Chemistry/Physical Parameters by APHA/EPA/ASTM Methods - Quality Control Analyte Sample Result QC Result Qualifier Units Spike Level %REC %REC Limits RPD RPD Limit Batch W8D *** DEFAULT PREP *** Duplicate (W8D0654-DUP1) Source: Prepared & Analyzed: 04/17/08 % Solids % by Weight Weck Laboratories, Inc Metals (Non-Aqueous) by EPA 6000/7000 Series Methods - Quality Control Analyte Sample Result QC Result Qualifier Units Spike Level %REC %REC Limits RPD RPD Limit Batch W8D EPA 3050B Blank (W8D0652-BLK1) Prepared: 04/17/08 Analyzed: 04/22/08 Total Arsenic... ND mg/kg wet LCS (W8D0652-BS1) Prepared: 04/17/08 Analyzed: 04/22/08 Total Arsenic mg/kg wet LCS Dup (W8D0652-BSD1) Prepared: 04/17/08 Analyzed: 04/22/08 Total Arsenic mg/kg wet Duplicate (W8D0652-DUP1) Source: Prepared: 04/17/08 Analyzed: 04/22/08 Total Arsenic... ND ND mg/kg wet 200 Matrix Spike (W8D0652-MS1) Source: Prepared: 04/17/08 Analyzed: 04/22/08 Total Arsenic mg/kg dry Matrix Spike Dup (W8D0652-MSD1) Source: Prepared: 04/17/08 Analyzed: 04/22/08 Total Arsenic mg/kg dry Lab#: Page 2 of East Clark Avenue, City of Industry, California (626) FAX (626)

112 Certificate of Analysis Contact: Hai Van Nguyen Authorized Signature (Project Manager) ELAP # 1132 LACSD # NELAC # 04229CA The results in this report apply to the samples analyzed in accordance with the chain of custody document. Weck Laboratories certifies that the test results meet all requirements of NELAC unless noted in the Case Narrative. This analytical report must be reproduced in its entirety. Notes: The Chain of Custody document is part of the analytical report. Any remaining sample(s) for testing will be disposed of one month from the final report date unless other arrangements are made in advance. All results are expressed on wet weight basis unless otherwise specified. ND = NOT DETECTED at or above the Reporting Limit. If J-value reported, then NOT DETECTED at or above the Method Detection Limit (MDL). Sub = Subcontracted analysis, original report enclosed. Dil = Dilution Factor MDL = Method Detection Limit MDA = Minimum Detectable Activity An Absence of Total Coliform meets the drinking water standards as established by the State of California Department of Health Services. The Reporting Limit (RL) is referenced as laboratory's Practical Quantitation Limit (PQL). For Potable water analysis, the Reporting Limit (RL) is referenced as Detection Limit for reporting purposes (DLRs) defined by EPA. If sample collected by Weck Laboratories, sampled in accordance to lab SOP MIS002 Flags for Data Qualifiers: Lab#: Page 3 of East Clark Avenue, City of Industry, California (626) FAX (626)