FIELD DOCUMENTS - Laserfiche WebLink

Home Browse Search

GEoENVIRO SERVICES, INC. ATTACHMENT A Soil Vapor Survey Sampling Procedures Former EZ-Serve 100966, 2531 Waterloo Road Stockton, California Soil Vapor Survey Scope GESI will conduct a soil vapor survey to evaluate vapor intrusion risk to indoor air in the building onsite. The survey will include the collection of shallow soil vapor samples in the vicinity of the building onsite. The data collected will be used to evaluate potential human health risks associated with exposure to hydrocarbons in soil vapor at the site. GEST will complete two temporary soil gas probes for collection of vapor samples. Vapor sampling will be completed in accordance with the Department of Toxic Substances Control (DTSC's) and Los Angeles Regional Water Quality Control Board's (LARWQCB's) "Advisory — Active Soil Gas Investigation" (DTSC and LARWQCB, 2003) and DTSC's "Interim Final Guidance for the Evaluation and Mitigation of Subsurface Vapor Intrusion of Indoor Air" (DTSC, 2005). Installation of Vapor Probes Each vapor probe will be completed by advancing 1.25-inch diameter steel rods equipped with a hardened steel tip. The probe will be advanced to 5-feet using hydraulic push methods. Once driven to total depth, the tip will be retracted to expose the vapor sampling port. A %-inch diameter nylon tube will extend from the sampling port to above ground surface. The probe will be sealed at the surface with granular hydrated bentonite for a minimum of 20 minutes prior to sampling. Soil Gas Sampling Following probe installation, a leak test and a purge volume test will be conducted according to DTSC protocol. Purging and sampling will be times so that the flow rate does not exceed 200 ml/minute. The probe tip and sampling tubing will be purged of 3 to 5 casing volumes, or a pre-determined volume based upon the purge volume test. Laboratory prepared Summa canisters containing a check valve to ensure the flow rate is less than 200 ml/min will be used to withdraw a soil gas sample from each probe location. Soil Gas Sample Analysis The soil gas samples will be collected in Summa canisters and submitted to a State-certified testing facility according to EPA Method TO-3. The samples will be analyzed within 72 hours of collection for total petroleum hydrocarbons as gasoline(TPHg), benzene, toluene, ethylbenzene, and xylenes (BTEX), and fuel oxygenates. 5529 Kailas Street - Ventura - CA - 93003 - T 805 . 642 . 1668 - F 805 . 642 . 9331 PO Box 7330 - Ventura - CA - 93006- 7330