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CVATC <br /> A S S O C I A T E S I N C <br /> Installation of Vapor Extraction and Groundwater Monitorin! Wells <br /> This phase will include the installation of three vapor extraction wells and two groundwater <br /> monitoring wells at the locations shown on Figure 2. The wells will be installed by a State C57- <br /> licensed drilling company utilizing hollow-stem auger drilling methods. <br /> A field geologist will be present to log drill cuttings and soil samples. Descriptions of soil types <br /> encountered and sample collection intervals will be recorded on boring logs. Soil samples will be <br /> collected at five-foot intervals. All soil samples will be field screened with a photo ionization <br /> detector (PID) for volatile organic compounds (VOCs). Soil cuttings generated from drilling <br /> activities will be stored on site in 55-gallon drums. Once the soil cuttings have been profiled for <br /> disposal, the drums will be transported to the Forward Landfill in Stockton, California. <br /> Well Construction Procedures <br /> The vapor extraction wells will be constructed of 2-inch diameter, schedule 40 PVC casing and <br /> 0.010" slot size screen. The bottom of the screen interval will be fitted with an end plug and the <br /> top of the casing will be fitted with an expandable, water-tight, locking cap. It is anticipated the <br /> well screen length in the vapor extraction wells will extend from a depth of 25 to 35 feet bgs. <br /> The groundwater monitoring wells will be installed downgradient from the former tank pit and <br /> will be utilized to monitor the downgradient concentrations of petroleum hydrocarbons in a lower <br /> water bearing zone. The wells will be constructed of 2-inch diameter schedule 40 PVC and will <br /> be completed to a depth of approximately 140 feet bgs. The groundwater wells will have 0.020" <br /> slot size screen from approximately 120 to 140 feet bgs. <br /> Sample Analysis <br /> Selected soil samples will be immediately placed on ice and delivered under chain-of-custody <br /> documentation to a State-certified laboratory for analysis. Samples will be analyzed for total <br /> petroleum hydrocarbons as gasoline (TPHg) by EPA Method 801513, BTEX by EPA Method <br /> 8021 B, and for fuel oxygenates by EPA Method 8260B. <br /> Groundwater Sampling <br /> Groundwater samples collected from the groundwater monitoring wells will be submitted using <br /> chain-of-custody record to a State-certified laboratory. Groundwater samples will be analyzed for <br /> TPHg by EPA Method 801513, BTEX by EPA Method 8021 B, and for fuel oxygenates by EPA <br /> Method 8260B. <br /> w:\14885\workplan\wkpin2005.doe 4 <br />