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S E C 0 R 76(Former 8P)Service Station No. 11193 SJCEHD August 30,2007 Page 3 Each well will be completed such that the potentiometric surface penetrates the screened interval. The borehole for well MW-13 will be completed as a two-inch diameter, Schedule 80 PVC groundwater monitoring well. The depth of the well and the length of the 0.010-inch slotted screen interval will be determined based on the depth of the next encountered water-bearing zone consisting of coarse- grained sediments. For wells greater than 50 feet deep, stainless steel, collar- type centralizers will be attached to the well casing string,just above thetop of the M well screen and at every 50 feet of blank casing. In addition, straightness of the well casing string will be maintained by suspending the casing throughout the well b( construction process until the annular seal has set. • Monitoring Well DevelopmentfSampling/Analysis. The newly installed groundwater monitoring wells will be developed by rigorously surging the wells over the length of the screen interval, and by purging approximately 10 casing volumes of water. Unless recharge takes more than two hours,wells are sampled once the well is recharged to within 80 percent of the pre-purge groundwater elevation. For very slow recharging wells (wells pumped dry during purging), samples may be collected after two hours of recharge. Groundwater samples will be collected and analyzed for the presence of total petroleum hydrocarbons as gasoline(TPHg), diesel range organics(DRO)with and without silica gel cleanup - (SGCU) benzene, toluene, ethylbenzene, and xylenes (BTEX), fuel oxygenates (methyl tert-butyl ether[MtBE], di-isopropyl ether[DIPS],tertiary amyl methyl ether F [TAME], ethyl tertiary butyl ether[EtBE], tertiary butyl alcohol[TBA]and ethanol), and lead scavengers (1,2-dichloroethane [1,2-DCA] and 1,2-dibromoethane [EDB]) by EPA Method 8260B. r. i • Well Surveying. Following installation,the newly installed groundwater wells will 1 be surveyed by a licensed surveyor to a local benchmark relative to mean sea level. Survey data including elevation, longitude, and latitude will be included in information uploaded to the State Water Resources Control Board (SWRCB) Geotracker Database (www.swrcb.neotracker.ca.aov) in accordance with Assembly Bill (AB) 2886 requirements. • Compliance with AB 2886 Requirements. Also per AB 2886 requirements, SECOR will electronically upload the data obtained during this investigation into the SWRCB Geotracker Database (www.swrcb.geotracker.ca.�ov). Documentation of the electronic data format(EDF)submittals will be included in the final report. • Soil and Water Disposal. Soil cuttings and purgelrinsate water generated during well installation activities will temporarily be stored in California Department of I Transportation (DOT)-approved, 55-gallon steel drums on-site pending ; 4 1:113P-ARC0105 BP-COP Sites1111931Work Plans111193 Vertical Delineation WP.doc I