|
I
<br /> Phase ll ESA —Work Plan
<br /> 2222&2244 S.Airport Way,
<br /> Stockton,California
<br /> October 27,2017
<br /> Page 4
<br /> eliminate all available head space, if possible, sealed, labeled and placed in a cooler chilled to 4 degrees
<br /> Celsius. The samples will be delivered following chain-of-custody procedures to BC Labs for organic
<br /> analyses. Well development and sampling will be completed in accordance with the California
<br /> Environmental Protection Agency, Department of Toxic Substances Control guidance manual Well
<br /> Design and Construction for Monitoring Groundwater at Contaminated Sites, June 2014.
<br /> 5.2 MONITORING WELL ELEVATION SURVEY
<br /> A licensed land surveyor will survey the wellhead elevations, referenced to NAVD88. The tops of the
<br /> well casings will be surveyed within a vertical accuracy of 0.01-foot and the horizontal position within
<br /> accuracy of 0.1-foot in order to comply with AB2886. The measuring point for water-level measurement
<br /> will be marked on the well collar. The surveyed wellhead elevations, along with depth to groundwater
<br /> measurements collected prior to well development/sampling, will allow calculation of the groundwater
<br /> gradient beneath the Site.
<br /> 6.0 LABORATORY ANALYSES
<br /> Soil gas samples will be analyzed for Volatile Organic Compounds (VOCs)by EPA Method TO-15. The
<br /> target constituents of concern for the former dry cleaner are tetrachloroethylene (PCE) and its associated
<br /> breakdown products, trichloroethylene (TCE); cis-1,2-dichloroethylene (DCE); trans-1,2-DCE, and vinyl
<br /> chloride. The constituents of potential concern in soil gas from former automobile fueling operations are
<br /> typically petroleum hydrocarbons gasoline (TPH-G), volatile organic compounds Benzene, Toluene,
<br /> Ethylbenzene, and Xylenes (BTEX), the oxygenated compound MTBE, and naphthalene. Laboratory
<br /> detection limits will be sufficient to determine whether a release exists and will be sufficient for
<br /> comparison to regulatory screening thresholds. 1,1-difluoroethane will be used during sampling as a leak
<br /> detection indicator and will also be analyzed in order to qualify sampling apparatus integrity.
<br /> Selected soil samples (up to three per boring) will be analyzed for potential constiuents of concern,
<br /> which may include the chlorinated solvents PCE, TCE, DCE, and vinyl chloride (by EPA Method
<br /> 8260B), petroleum hydrocarbon constituents TPH-D, TPH-G, BTEX, oxygenated gasoline additives,
<br /> including MTBE, and naphthalene (by EPA methods 8015M, 8260B), polynuclear aromatic
<br /> hydrocarbons (PAHs, by EPA Method 8270C), and fCAM 17 Metals (by appropriate EPA methods).
<br /> Laboratory detection limits will be sufficient to determine whether a release exists and will be sufficient
<br /> for comparison to regulatory screening thresholds.
<br /> Groundwater samples will be analyzed for the chlorinated solvents PCE, TCE, DCE, and vinyl chloride
<br /> by EPA Method 8260B, for petroleum hydrocarbon constituents (TPH-D, TPH-G, BTEX, oxygenated
<br /> gasoline additives, including MTBE, and naphthalene)by appropriate EPA methods(8015M, 8260B), for
<br /> PAHs by EPA Method 8270C, and for CAM 17 Metals (EPA methods vary). Laboratory detection limits
<br /> will be sufficient to determine whether a release exists and will be sufficient for comparison to regulatory
<br /> screening thresholds.
<br /> 7.0 REPORTING
<br /> Condor will evaluate the laboratory analytical results, qualify the data, and compare results to regulatory
<br /> screening thresholds. Condor will prepare a report detailing the investigation including: detailed geologic
<br /> logs, laboratory analytical results, and conclusions/recommendations. The deliverables will include one
<br /> electronic copy of the report and up to three hard copies, if requested. Additional hard copies can be
<br /> included for additional fees if requested.
<br /> A *&4.
<br /> to CONDOR
<br />
|