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with new 2-such diameter brass and/or stainless steel sleeves, which enabled soil identification and ' subjective evaluation of contamination A flame ionization detector (FID) was used to monitor for the presence of flammable volatile compounds in the soil Soil samples collected from the ' capillary fringe and bottom of the bonngs from wells MW5 through MW8 were sealed, labeled, and immediately placed in an ice chest at a temperature of approximately 4 degrees Centigrade ' for transport to Argon under chain of custody protocol ' All down-hole drilling equipment was decontaminated using a steam cleaner Sampling equipment I was decontaminated by washing in a solution of water and Alconox(D and rinsing twice with water ' Soil cuttings were stockpiled on-site, placed on and covered with 6-msI plastic sheeting Rinsate from decontamination activities was placed in labeled 55-gallon drums approved by the California ' Department of Transportation(DOT) for storage of hazardous waste ' Based on stratigraphy and initial depth to groundwater observed in the borings, wells MWS through MW8 were screened from approximately 52 to 72 feet bgs with 0 010 Inch slotted screen The wells were constructed of 2-inch diameter, Schedule 40 PVC casing from the bottom of the well to approximately two feet above the ground surface The filter pack consisted of 2/16 silica sand and was placed from the bottom of the well to approximately 50 feet bgs The annular seal contained two feet of bentonite overlain by neat cement grout to the ground surface The grout was pumped ' into the annulus and emplaced using a tremae pipe The monitoring wells were secured at the ground surface with expandable, locking plugs and locking, stovepipe well monuments Well tconstruction details are depicted on the bonngs logs contained in Appendix I I4.3 Mud Rotary Drilling and Installation of Intermediate Zone Monitoring Well Between October 17 and October 23, 2000, Spectrum advanced one boring to a depth of approximately 135 feet bgs using a Gardner-Denver mud rotary ng under the supervision of field geologists Sean Garvey and Justin Power The boring was subsequently competed as well (MW9B) rin the 120-foot aquifer Well locations are presented on Figure 3 IA bentonite based drilling mud was maintained to an overbalanced condition {9 1-9 4 lbs/gal) to \� prevent fluid entry into the borehole The relative percentage of sand in the upper 70 feet of soil 7 datalgroundzeAuleburg/reports/mud_has_wel lrepwtdoc I l �