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LOF Glass I idward-Clyde Consultants May 6, 1985 Page 3 surface and subsurface, and electrical interference from power lines precluded the use of the technique over much of the area although some anomalies were noted to the south of the leak which could represent the presence of oil. On April 4 and 5, twelve groundwater monitoring wells were installed at the site. Ten of the wells were situated in the spill area while the other two were located in front of the facility. Four of the wells in the spill area (Wells 7 through 10) were completed to a depth of 20 ft. with the screened interval located from 5 to 20 ft. below grade. The remaining eight wells were completed to a depth of 15 ft. with the screened interval located from 5 to 15 ft. The wells were installed with a water rotary drill rig using water only. The wells were completed with 1/4 inch semi-rounded pea gravel as the well pack extending to 1 1/2 ft. above the screened interval and followed by a 1 ft. bentonite plug and concrete over the remaining 2 to 3 ft. to the surface. An 8 in. concrete Christy Box was used to cover the well at the surface. Additional well construction data is given in Figure 2. The locations of the wells are given in Figure 3. Following completion, the wells were developed by pumping for 5 to 6 minutes with a flow rate of approximately 7 gpm (35 to 40 gallons total) . During well development, and also during the drilling, some oil was observed in the development and drilling water from Wells 9 and 10. On Monday, April 8 the wells were pumped again for approximately 3 minutes to purge the equivalent of 3 casing volumes of water prior to sampling. Water quality samples were then taken from Wells 1, 2, and 6 through 11 with a teflon bailer. The samples were sent to EAL, an independent lab, to be analyzed for oil in water (e.g. , suspended droplets) and dissolved hydrocarbons. Water level measurements were also taken before pumping and the relative elevations of the top of each well casing were surveyed. An additional site visit was made on Monday, April 15 to take a second set of water level measurements and visually inspect the wells for the presence of oil.