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Following the placement of the sand packs, Mitchell Drilling developed the wells by the surge and ' purge method Each well was surged for approximately 5 minutes using a wire-line surge block system Between surging cycles, approximately 5 gallons of groundwater were bailed from the wells Following well development, three feet of hydrated bentonite chips were placed within the ' annular spaces between the boreholes and the well casings Surface seals of neat cement grout were placed over the hydrated bentonite, under EHD observation The tops of the wells were ' secured with watertight caps and 8-inch diameter, traffic-rated, flush-mounted utility boxes On December 18, 2003, Morrow Surveying (California Licensed Land Surveyor#5161) surveyed the newly-installed wells into the existing monitoring well network Morrow Surveying located the wells using GPS coordinates, and measured the elevations of the tops of the well casings to the nearest 0 01 foot, referenced to the city of Stockton benchmark#113 (Elevation 19 51 feet) The surveyor's report is included as Appendix B 2 2 2 Soil Sampling and Analysis ' During all of the drilling, soil samples were collected at five-foot intervals using a modified California split-spoon sampler lined with 2-inch diameter by 6-inch long stainless steel sleeves A Ramage Environmental field geologist logged each of the soil samples for geologic and hydrogeologic characteristics, and screened each sample for organic vapors using a photoionization detector (PID) The monitoring well logs are included as Appendix C 1 After consulting with the EHD specialist, the soil samples collected at 45 and 55 feet bgs from all three well borings, plus the soil sample collected at 35 feet bgs from MW-6 were submitted for laboratory analysis, to further evaluate the extent of impacted soil These seven soil samples were sealed with Teflon®film and plastic end caps, and transported in an iced cooler with chain- of-custody documentation to Excelchem Environmental Labs (Excelchem), a state of California certified hazardous waste testing laboratory (Certification #2119) Excelchem analyzed each of the soil samples for TPH-as-gasoline and BTEX by EPA Method 8020/8015M, and for oxygenates ' (MTBE, DIPE, ETBE, TAME, TBA), and 1,2-dichloroethane (1,2-DCA) by EPA Method 8260B 2 2 3 Groundwater Monitoring, Sampling and Analysis ' On December 19, 2003, Ramage Environmental monitored and sampled groundwater from the new and existing wells Depth-to-groundwater was measured to within 0 01-foot in each of the wells using a water level indicator A 0 10-foot thick layer of separate-phase hydrocarbons (I e , ' free product) was observed in MW-1 8