SR2501523 - Laserfiche WebLink

Home Browse Search

Cleanup in Vulnerable Communities'Initiative Discovery Project Reference:Favorite Cleaners and Enforcement Discovery Investigation Work Plan Project Number:60688620 Soil Vapor and Sub-Slab Vapor Samples Collection Protocols for collecting soil vapor samples from the soil vapor probes and sub-slab vapor pins will generally follow Section 4.0 of the DTSC's Soil Gas Advisory(DTSC 2015b). Sub-slab vapor samples will be collected concurrently with indoor air samples. Sub-slab vapor samples will be collected shortly after indoor air samples to provide indoor air/sub-slab vapor data.This protocol will minimize the potential for VOCs to be released to indoor air during sub-slab vapor sampling. In addition,the following activities will be performed. 1. Three purge volumes will be removed prior to sample collection using a pump(handheld battery operated Gilian GilAir Plus pump or similar)prior to sample collection. 2. Shut-in testing will be conducted. 3. Leak checking will be conducted with liquid tracers, such as isopropyl alcohol.A shroud will be placed over the canisters and filled with the tracer gas.Any detection of the tracer compound above 5% is considered a leak, and re-sampling is warranted. 4. A soil vapor/sub-slab vapor field sampling sheet,for the recording of all field parameters upon sampling, will be completed for each soil vapor sample collected. 5. Soil vapor and sub-slab vapor samples will be analyzed via USEPA Method TO-15 as indicated in the Programmatic QAPP. USEPA Method TO-15 SIM analysis will be National Environmental Laboratory Accreditation Program (NELAP)-certified, and USEPA Method 8260 will be certified for groundwater.The laboratory protocols for USEPA Methods 8260 and TO-15 SIM should follow the recommendations in Appendix F of the DTSC's Soil Gas Advisory(DTSC 2015b)and the guidelines in USEPA Method SW-846. 6. Summa®canisters will be batch-certified for cleanliness. 7. The soil vapor and sub-slab vapor samples will be analyzed for the full suite of analytes including, but not limited to benzene,toluene, ethylbenzene, xylenes(BTEX); naphthalene;freons; PCE2;trichloroethylene(TCE)3; and their breakdown products. 8. Analytical reporting limits will meet appropriate and applicable risk-based screening levels for each analyte reported. 9. Soil vapor samples will not be collected within 5 days of a rainfall event of more than a half-inch of precipitation. Note that this protocol may be Iithologically dependent, i.e.,tighter soils may require longer wait times. 10. If the analytical results of the soil vapor sampling are below vapor intrusion screening levels,then an additional round of sampling will be conducted before risk-based decisions are made.The additional round of sampling will be collected in the opposite season(rainy versus dry). 3.2.5.3 Soil Sampling No soil matrix samples will be collected for laboratory analyses for this investigation. 3.2.5.4 Groundwater Sampling According to information provided by the SWRCB online GeoTracker database,depth to groundwater measured at the TEXACO(T0601995911)site located at 3089 East Tulare Avenue, approximately 1,230 feet to the south of the Subject Property,was measured at depth of approximately 100 feet bgs in 2002, and the groundwater flow direction was noted in the northwestern direction. More recent groundwater depths were not found during the Phase I ESA for the Subject Property, and actual groundwater depths cannot be determined without further evaluation. Groundwater samples will be collected following the HydropunchT"^sampling technique(or equivalent). When collecting groundwater grab samples for the evaluation of potential impact of contaminant releases,the following should be considered: • The uppermost section of the shallowest water-bearing unit should be subject to grab sampling. 2 Can be defined as perch loroethyl ene,tetrachloroethene,or tetrachloroethylene 3 Can be defined as trichloroethene or trichloroethylene Prepared for: California Department of Toxic Substances Control AECOM 16