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Li 1.001, 20 November 2003 AGE-NC Project No. 96-0263 Page 9 of 11 9.0. FIELD PROCEDURES All field procedures will be overseen by an AGE representative under the supervision of a California Registered Geologist. Procedures for installation of ozone sparge wells, soil sampling sampling of ground water monitoring wells are outlined below. 9.1. IOS WELL INSTALLATION The proposed wells will be installed utilizing a truck-mounted drill rig equipped with 8.25-inch L, diameter hollow stem augers. The hollow stem augers will be cleaned prior to advancement of each borehole.The shallow and deep ozone sparge wells will be advanced to depths of approximately 20 and 44 feet bsg, respectively. The ozone sparge wells will be completed with manufacturer-assembled 2-inch by 30-inch microporous sparge points and casings. The sparge points will be installed at a depth of E- approximately 20 feet bsg in the shallow water zone and at approximately 44 feet bsg in the deeper water bearing zone. The well materials will be placed into the borehole through the interior of the hollow-stem augers. After installing the sparge point and casing, filter pack material consisting of pre-washed #2/16 sand will be added from the bottom of the borehole to approximately two feet above the sparge point. A nominal two-foot thick bentonite seal will be placed above the filter pack of each well to minimize the potential of grout penetration into the filter pack or screened section of the well. The bentonite seal will be formed by pouring bentonite chips into the annulus and allowing them to settle on the filter pack. Bentonite chips will be hydrated using five gallons of water. The bentonite chips will be allowed to hydrate for a minimum of one-half hour prior to grouting. w. Following hydration of the bentonite chips,the remaining annular space will be filled to within one foot of the ground surface with a cement grout. The grout mixture will consist of type LE portland ,r neat cement and not more than 6 gallons of water per 94-pound sack of cement. The grout will be placed by pumping through a tremmie pipe or the hollow stem augers.For inspection purposes, the EHD will be notified at least 48 hours prior to conducting grouting procedures. A3/4-inch PVC riser �. will connect the sparge points to the distribution system and ozone generator. A traffic-rated well box will be installed over each sparge well. +- Soil samples will be collected, preserved, logged and analyzed as specified in Section 8.3. Soil samples will be collected at 5 and 10 feet bsg. Soil cuttings will be temporarily stored in DOT- approved 55-gallon drums pending laboratory analyses for proper disposal. LM Advanced GeoE nvi ron mental,Inc.