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VkTc <br /> ATC Associates Inc. <br /> 1117 Lone Palm Avenue, Suite B <br /> Modesto,California 95351 <br /> 209-579-2221 <br /> A s s o c i A T E S I N C . fax:209-579-2225 <br /> SCOPE OF WORK <br /> Planning and Permits <br /> ATC has prepared the drilling permit applications for the proposed subsurface investigation. <br /> The permits and associated fees will be submitted separately from this document. ATC will also <br /> schedule field personnel and equipment, notify Underground Services Alert to locate <br /> underground utilities as required, utilize a private locator, and perform other necessary field <br /> preparation and job start-up activities. <br /> Installation of a Vapor Extraction Well <br /> This phase will include the installation of one additional vapor extraction well at the location <br /> shown on Figure 2. ATC proposes to locate the well as close to the locations of borings SBA <br /> and SB-2 while avoiding utilities and other underground objects as these borings were <br /> immediately adjacent to the former USTs. Historically, the soil samples collected from borings <br /> SB-1 and SB-2 have contained the highest detectable concentrations of petroleum hydrocarbons. <br /> The well will be installed by a State C57-licensed drilling company utilizing hollow-stem auger <br /> 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 <br /> be collected at five-foot intervals. 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 well 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. A well screen <br /> length in the vapor extraction well will extend from a depth of 20 to 30 feet bgs. ATC is <br /> proposing a limited screen interval in an attempt to improve vapor recovery at the site and limit <br /> circumventing through the former tank pit. Above the screen will be a sand layer from 18 to 20 <br /> feet bgs, a bentonite layer from 16 to 18 feet bgs, and grout filling from 0 to 16 feet bgs. A <br /> traffic-rated well box will be installed flush with the surface. <br /> sA14885\workp1ans\wkp1n 11-20-06.doc 4 <br />