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Stantec <br /> June 16,2010 <br /> Page 2 of 4 <br /> RE: Notification of Action -Soil Vapor Extraction Pilot Testing <br /> ❑ Well Permit – a completed well permit application and fee will be submitted to the San Joaquin <br /> County Department of Environmental Health for the proposed SVE test well and observation point <br /> locations. <br /> ❑ USA Notification and Utility Survey – Stantec will mark the locations of the proposed wells in white <br /> paint, and notify Underground Service Alert (USA) at least two days before drilling. In addition, <br /> Stantec will contract with a private utility locator to confirm that proposed drilling locations are free of <br /> detectable subsurface utilities. <br /> TASK 2—SVE PILOT TEST PROCEDURES <br /> The borings for the six-inch diameter PVC SVE test well and six associated observation points will be <br /> advanced by Woodward Drilling, a California C-57 licensed driller. The following summarized the installation <br /> and testing program. <br /> Extraction Well Installation <br /> A single six-inch PVC SVE extraction test well will be installed directly into the former oil tank, in close <br /> proximity to previous boring SB-6. The test well will be installed to the base of (but not through) the former <br /> tank, estimated to be about 12 feet in total depth (i.e., to the total depth of the tank) (Figure 1). The boring for <br /> the extraction well will be advanced using hollow stem auger methods, and the well will be constructed with <br /> screen from approximately 7 to 12 feet below ground surface (bgs). The well screen interval has been <br /> selected based on observations at boring SB-6 with regards to the presence of volatile contaminants, and to <br /> minimize the potential for introduction of atmospheric air into the well during extraction (i.e., too shallow of a <br /> screen interval could introduce air from the surface into the well). <br /> To facilitate SVE testing, the well will be completed at the ground surface with neat cement and approximately <br /> one to two feet of PVC blank casing will extend above the ground surface. A well box will not be installed. <br /> Upon completion of testing, the well will be secured with a locking plug. Based on the result of the SVE <br /> testing, the well will either be properly destroyed or converted to facilitate a full-scale SVE system. <br /> Observation Point Installation <br /> Up to six (6) Yz-inch to one-inch diameter PVC observation wells will be installed outside the estimated tank <br /> boundaries, to be used during SVE testing to observe radius of influence. Conceptual observation well point <br /> locations are depicted on Figure 1; final locations will be determined in the field. Boreholes for the <br /> observation wells will be advanced using direct push Geoprobe rig, and the PVC wells will be installed and <br /> constructed directly in the open borehole. Well depths will vary, generally ranging from 5 to 15 feet bgs with <br /> the intent of measuring both lateral and vertical influence of applied vacuum at the SVE test well. <br /> Observation well screen lengths will be 5 feet(i.e., intervals will generally be 5 to 10 or 10 to 15 feet bgs). <br /> The observation wells will be completed at the ground surface with neat cement and approximately one to two <br /> feet of PVC blank casing will extend above the ground surface. A well box will not be installed. Upon <br /> completion of testing, the wells will be secured with a locking plug. Based on the result of the SVE testing, <br /> the wells will either be properly destroyed or fitted with flush mounted locking well boxes to facilitate collection <br /> of additional data during operation of a full-scale SVE system. <br /> LNPG&EIodi MGP�SVE Pilot Test\NOA Letter FNL-06 16 10.doc <br />