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HomeMy WebLinkAboutSoils 5/21/2012CALIFORNIA Water Boards Central Valley Regional Water Quality Control Board 21 May 2012 Mr. Drew Squyres Pacific Gas and Electric Company 4325 S. Higuera Street San Luis Obispo, CA 93401 EDMUND G. BROWN JR. GOVERNOR < MATTHEW RomoUEZ SECRETARY FOR ENVIRONMENTAL PROTECTION REVIEW OF TECHNICAL MEMORANDUM, S * ITE-SPECIFIC SOIL MANAGEMENT SCREENING PROCESS FOR DEMOLITION-RELATED ACTIVITIES, FORMER PG&E KERN POWER PLANT, 2401 COFFEE ROAD, BAKERSFIELD, KERN COUNTY (SITE ID — 2050001) Jacobson James & Associates, Inc. (JJ&A) prepared and submitted on your behalf a technical memorandum Site-Specific Soil Management Screening Process For Demolition-Related Activities, Kern Power Plant, -Bakersfield, California, dated 9 April 2012. Central Valley Water Board staff (Staff) has reviewed the technical memorandum (Tech Memo). The Tech Memo proposes a soil management screening process for "waste soil" generated during complete demolition of Site facilities including the power plant building, cooling towers, fuel tanks and pipelines, and support buildings. Waste soil classification will be determined through chemical analyses of soil samples and comparison of those analytical results to regulatory classification threshold concentrations and selected site screening levels. The analyses performed will be those constituents of concern (COCs) associated with the area of origin at the, Site based upon prior facility operations, the data generated through prior Site investigations and remediation, and the on-going remediation work for the fuel related plume in groundwater, associated with the former Sunland Oil Refinery. The concentrations of COCs are used to determine if the waste soil is classified as Resource. Conservation and Recovery. Act (RCRA) hazardous waste, is a non-RCRA hazardous waste, or if it exceeds onsite reuse screening criteria. A Soil Management Process Diagram, Figure 1, from the Tech Memo is enclosed. Soil management option's will include. on-site reuse, on-site treatment for reuse either on-site or off-site, and off-site disposal., If the "waste soil" is determined not to be hazardous waste, it will be screened for possible on- site reuse by comparing COC concentrations to a "Selected Site Screening Level" (SSSL). Each COC specific SSSL was determined by selecting the lowest screening value from the US EPA Regional Screening Levels (RSLs); the California H ' uman Health Screening Levels (CHHSLs); and the California Regional Water Quality Control Board, Region 2 Environmental Screening Level's (ESLs); but not lower than background conditions, if applicable. If the lowest screening level was below background conditions for that COC, then the background concentration would be the SSSL. KARL E. LONGLEY ScD, P.E., CHAIR PAMELA C.,CREEDON P.E., BCEE, EXECUTIVE OFFICER 1685 E Street, Fresno, CA 93706 1 www.waterboards.ca.gov/centrai.valley RECYCLED PAPER Mr. Drew Squyres - 2 - 21 May 2012 Site-specific background concentrations, of 19 metals in soil were previously reported in the Phase 11 Environmental Site Assessment (Phase 11 Report) by IT Corporation (10 August 2000). During the Phase 11 assessment, thirteen soil samples from various areas of the Site, purportedly unaffected by facility operations, were collected and analyzed, and the results used to calculate statistical parameters for each constituent, including the 95% Upper Tolerance Limit (UTL) (log normal) value. Censored data, data where the laboratory result was "none detected" or ND, was addressed by using "one half the reporting limit)) value for the statistical analysis. The Tech Memo utilizes the 95% UTL values from the Phase 11 Report, as "Site Specific Ambient Thresholds" (concentrations) for metals in soils. These "Site Specific Ambient Thresholds" are used as background conditions and compared to the screening levels in determining the SSSL. If the background condition value is above the lowest screening level, the background condition concentration is chosen as the SSSL. The Tech Memo states that all information pursuant to soil management will be documented for on-Site, on-Site Treatment, and off-Site disposal. Documentation will include the source, volume, and ultimate soil disposition of the managed soil. Copies of all sample collection records, analytical data, and manifest/bills of lading will be retained and accessible in the project file. The. locations and quantities of soil treated and/or reused at the Site will be field documented and included in the Site records. The Tech Memo states that the demolition activities may occur over a multi-year period and that it is anticipated that project status reports will be prepared by PG&E (or its contractors) during the demolition- project.. Soil management activities will be documented in the project status reports, which will identify the volume, source, and chemistry of soil managed during the project, and its final disposition. COMMENTS Staff generally agrees with the soil screening process methodology proposed. However, staff has the following comments regarding the Tech Memo: 1. JJ&A needs to define "waste soils", how "waste soils" will be identified in the field, and how "waste soils" will be handled on Site until final disposition is determined. 2. In Table 2 of the Tech Memo, the Total Threshold Limit Concentration (TTLC) for the compound Endrin is listed as 2 milligrams per kilogram (mg/kg). This appears to be incorrect. The correct TTLC value for Endrin is 0.2 mg /kg. 3. In Table 4 of the Tech Memo, the Environmental Screening Level (ESL) for the constituent silver in soil in an industrial land use scenario is listed. as 10 mg/kg. This appears to be incorrect. The correct ESL value for silver in soil in an industrial scenario is 40 mg/kg. 4. In Figure 1, Soils Management Process Diagram, a rounded rectangle, near the lower- right corner, contains the statement, "Dispose of soil off Site as non-hazardous waste (landfill or recycling alternative to be...". This statement a . ppears to be incomplete. Figure 1 needs to be revised to complete this statement and Figure I resubmitted. 5. Table 3-1 and laboratory analytical data (Appendix B) of the Phase 11 Report indicates that sample results of ND (none detected) were incorrectly ctly entered into Table 3 as being less than the Practical Quantitation Limit (PQL) instead of being less than the Method Mr. Drew Squyres - 3 - 21 May 2012 Detection Limit (MDL), both of which are reported in the analytical data summary in Appendix B. This is apparent when data values above. the MDL but below the PQL are reported in Table 3. Although not directly incorporated into'the Tech Memo, it is believed these errors may be related to the issue identified in Comment No. 6 below. 6. Apparent errors were identified in data incorporated into the Tech Memo that originated from the Phase 11 Report. The previous statistical analyses, including the calculated 95% UTLs, reported in the Phase 11 Report appear to be incorrect. The statistical analyses in the Phase 11 Report incorrectly substituted one half the PQL for ND results (censored data) instead of one half the MDL, which was the actual detection limit. Therefore, the statistical analyses for any constituent that contained one or more samples with an ND result appear to be invalid. To remedy this, a new statistical analysis of the previous soil data will need to be performed that meets current statistical standards for environmental investigations, including the incorporation of censored data (ND results). For consistency,' it is recommended that a new statistical analysis of all the prior soils data be performed. This should not be too onerous a task due to the limited number of constituents and sample results. Once the new statistical data are generated, the SSSLs for metals constituents should be re-evaluated and modified if necessary. 7. A review of Table 3 of the Phase 11 Report also indicated what appeared to be outliers in the data. This is most apparent in sample KG021305-7029 for the constituent zinc. The reported result for zinc in this sample is 248 mg/kg, which is significantly higher than the results for zinc in the 12 remaining samples, which ranged from 23.7 to 53.2 mg/kg. Although not as pronounced, the concentrations of copper, lead, and nickel also appear to be noticeably higher in sample KG021305-7029 as compared to the other sample results for these same constituents. This sample was collected at the ground surface and in the general vicinity of identified "waste material" piles in the "Drainage Pond' Area", identified in the Phase 11 Report. Concentrations of zinc, copper, lead, and nickel in a soil sample collected in the same boring at a depth of 4.5 feet did not appear to be elevated and were consistent with the results of the remaining 12 soil samples. Based upon the above, soil sample KG021305-7029 may be affected by facility operations and not indicative of background soil conditions for the constituents of zinc, copper, lead, and nickel. JJ&A needs to re-evaluate the suitability of some if not all analytical results for sample KG021305-7029 to represent soil conditions not affected ,by facility operations. In addition, the new statistical analysis to be performed under Comment No. 6 above needs to include an outlier analysis to help identify sample results that may not be appropriate to include in the statistical analysis. 8. Quarterly project status reports, including copies of laboratory analytical reports, will need to be submitted when demolition activities are occurring and one project summary report after demolition activities are completed. To help reduce the volume of the status and summary reports, the associated laboratory analytical reports may be submitted as pdf file(s) on a compact disk with each project report. 9. Additional specific information regarding soil sampling is needed including the frequency, if composite samples will be utilized, etc. 10. The Tech Memo and all subsequent correspondence and. reports need to be uploaded into the State Water Resources Control Board's GeoTracker database. Mr. Drew Squyres - 4 - 21 May 2012 Please submit an addendum to the Tech Memo that addresses Staff comments above. ' If you have any questions or wish to discuss these comments, please contact me at- (559) 444 -2484 or by email at dcarlson(c-Dwaterboards.ca.gov. DANIEL L. CARLSON Senior Engineering Geologist PG 5379, CEG 1695, CHG 488 Enclosure DLC:RWW:dlc cc: Mr. Joel Bauman, Jacobson James and Associates, Roseville Mr. Howard Wines, Bakersfield Fire Department, Bakersfield Kern County Public Health Services Department, Environmental Health Division, Bakersfield FIGURE 1 SOIL MANAGEMENT PROCESS DIAGRAM Site- Spedfic Soil Management Screening Process for Demolition - Related. Activities Kern Power Plant Bakersfield, California Notes: CA WET = California Waste Extraction Test RCRA = Resource Conservation and Recovery Act STLC = Soluble Threshold Limit Concentration TCLP= Toxicity Characteristics Leaching Procedure JACOBSON I JAMES TTLC = Total Threshold Limit Concentration 1 of 1 & a s s c c i a i e s. i n c