ARCHIVED REPORTS_2019 SOIL MGMT PLAN (MAY)

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metal analyses are performed, only those metals (CAM 17 /Title 22) to which risk levels have been assigned need to be evaluated. At present, the DTSC is working to establish California Screen- ing Levels (CSL) to determine whether some com- pounds of concern pose a risk. Until such time as these CSL values are established, DTSC recom- mends that the DTSC PEA Guidance Manual or an equivalent process be referenced. This guid- ance may include the Regional Water Quality Control Board's (RWQCB) guidelines for reuse of non -hazardous petroleum hydrocarbon con- taminated soil as applied to Total Petroleum Hy- drocarbons (TPH) only. The RWQCB guidelines should not be used for volatile organic compounds (VOCs) or semi -volatile organic compounds (SVOCS). In addition, a standard laboratory data package, including a summary of the QA/QC (Quality Assurance/Quality Control) sample re- sults should also accompany all analytical reports. When possible, representative samples should be col- lected at the borrow area while the potential fill ma- terial is still in place, and analyzed prior to removal from the borrow area. In addition to performing the appropriate analyses of the fill material, an ap- propriate number of samples should also be deter- mined based on the approximate volume or area of soil to be used as fill material. The table above can be used as a guide to determine the number of samples needed to adequately characterize the fill material when sampled at the borrow site. Alternative Sampling A Phase I or PEA may be conducted prior to sam- pling to determine whether the borrow area may have been impacted by previous activities on the property. After the property has been evaluated, any sampling that may be required can be determined during a meeting with DTSC or appropriate regu- latory agency. However, if it is not possible to ana- lyze the fill material at the borrow area or deter- mine that it is appropriate for use via a Phase I or PEA, it is recommended that one (1) sample per truckload be collected and analyzed for all com- pounds of concern to ensure that the imported soil is uncontaminated and acceptable. (See chart on Potential Contaminants Based on the Fill Source Area for appropriate analyses). This sampling fre- quency may be modified upon consultation with the DTSC or appropriate regulatory agency if all of the fill material is derived from a common borrow area. However, fill material that is not characterized at the borrow area will need to be stockpiled either on or off-site until the analyses have been completed. In addition, should contaminants exceeding accep- tance criteria be identified in the stockpiled fill material, that material will be deemed unacceptable and new fill material will need to be obtained, sampled and analyzed. Therefore, the DTSC rec- ommends that all sampling and analyses should be completed prior to delivery to the site to ensure the soil is free of contamination, and to eliminate un- necessary transportation charges for unacceptable fill material. Composite sampling for fill material characteriza- tion may or may not be appropriate, depending on quality and homogeneity of source/borrow area, and compounds of concern. Compositing samples for volatile and semivolatile constituents is not accept- able. Composite sampling for heavy metals, pesti- cides, herbicides or PAH's from unanalyzed stock- piled soil is also unacceptable, unless it is stockpiled at the borrow area and originates from the same source area. In addition, if samples are composited, they should be from the same soil layer, and not from different soil layers. When very large volumes of fill material are antici- pated, or when larger areas are being considered as borrow areas, the DTSC recommends that a Phase I or PEA be conducted on the area to ensure that the borrow area has not been impacted by previous activities on the property. After the property has been evaluated, any sampling that may be required can be determined during a meeting with the DTSC. Forfurtherinformation, callShahir Haddad, P.E. at (714) 484-5368.