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• Mr Harlan Knoll Page 2 of 5 Soil samples collected at the depth of approximately 5 feet below ground surface (bgs) and 20 feet bgs from each boring were submitted for laboratory analyses The samples were sealed and labeled, then immediately placed in an ice chest cooled to a temperature of approximately 4° C The samples were transported under chain of custody to Argon Laboratory (Argon, ELAP #2359), and analyzed for total petroleum hydrocarbons as gasoline (TPHg) and diesel (TPHd) using EPA method 8015M, for benzene, toluene, ethylbenzene, and xylenes (BTEX) using EPA method 8020, and and for oxygenated gasoline additives including the lead scavengers 1,2-dichloroethane (1,2-DCA), and ethylene dibromide (EDB) using EPA Method 8260B All work conducted at the site was performed under the supervision of Ground Zero geologist Sean Garvey and project manager John Lane, who is a California Registered Geologist Mr Harlan Knoll of EHD was present to inspect the placement of the grout seals All drilling and sampling equipment was decontaminated prior to use and between sample collection to minimize cross contamination Soil generated during drilling activities was placed on and covered with plastic sheeting Wastewater generated was placed in a DOT approved 55-gallon drum Both waste streams are currently stored on site pending disposal 1.3 Well Construction • Based on the lithology and the initial depth to groundwater observed during drilling, wells MW5, MW6, and MW7 were screened from approximately 4 feet bgs to 19 feet bgs The wells were constructed of 2-mch diameter, Schedule 40 PVC casing The well intakes are comprised of Schedule 40 PVC casing with 0 010-inch slots The filter pack consists of#2/12 silica sand from the bottom of the well to approximately 15 feet above the slotted interval The annular seals consist of 15 feet of hydrated bentonite pellets overlain by 1 foot of concrete The wells were completed with traffic-rated, grade-level well boxes, and locking well caps Boring/well construction logs are included in Attachment A 1.4 Well Development and Groundwater Sampling Groundwater levels in all site wells were monitored and the newly installed wells were developed and sampled on November 4, 2002 The depth to groundwater ranged from 6 15 feet bgs in well MW6 to 8 73 feet bgs in well MW3 Field data sheets are included in Attachment B The newly installed wells were developed by surging and pumping until turbidity was minimized Groundwater physical parameters (temperature, pH, and electrical conductivity) were measured during well development Purged groundwater was placed into DOT approved 55-gallon drums, which are currently stored on site pending disposal Groundwater samples were collected the physical parameters stabilized and the water level in the well recovered to at least 80% of the pre- purged level The samples were submitted to Argon for analysis of TPHg and TPHd by EPA method 8015M, for BTEX by EPA method 8020, and for oxygenated gasoline additives and lead scavengers by EPA method 8260 Well development logs are included in Attachment B G\Data\GROUNDZE\Barnyard-Manser\Reports\WELLS RPT MW 5_6_7 doc