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Report for Monitor Weh-.91mpling and Groundwater Investigation Pilkington North America July 23,2003 Page 3 Following the well collar survey activities, Condor conducted a water level survey at the four monitor wells. At each monitor well, Condor measured the depth to groundwater from the monitor well collar with a flat tape, electrical sounding device to 0.01 foot. Following the water level survey activities, groundwater sampling activities at MW-17 and MW-18 were initiated. For each monitor well, a single-use, disposable bailer was used to collect a field inspection sample. The field inspection sample was observed for a potential floating product layer, petroleum hydrocarbon odor, and general appearance. Following this initial groundwater inspection, the well was purged with the disposable bailer of three times the initial volume of groundwater in the well. The purge water was tested several times during the purging for pH, conductivity, and temperature with field instruments calibrated to manufacturer recommended standards to monitor the completeness of the purge. Each groundwater sample was collected by carefully draining the disposable bailer with a bottom- emptying device into three laboratory-supplied volatile organic analysis vials containing hydrochloric acid(HCl) as a preservative. The sample containers were stored in a cooler chilled with ice and delivered under chain-of-custody procedures to Argon Laboratories of Ceres, California, for analyses. All field observations and measurements were recorded on field logs during the surveying and sampling process (Attachment B). The groundwater samples were analyzed for TPH-G by EPA Method 8015B and for BTEX and gasoline oxygenates by EPA Method 8260B. The gasoline oxygenates included MTBE, ethanol, TBA, ETBE, DIPE, TAME, 1,2-DCA, and EDB. The detection limit for TPH-G was 50 gg/L and ranged from 0.5 to 5.0 µg/L for BTEX and the gasoline oxygenates. Soil and Groundwater Investigation Condor conducted a soil and groundwater investigation at the 1997 UST removal site on July 2, 2003. Four direct push borings (GP-1 through GP-4) were advanced at the site for the purpose of collecting a soil sample at approximately 12 feet below grade and a shallow groundwater grab sample. The locations of the borings are shown in Figure 4, Attachment A. For each boring, the soil encountered was logged in accordance with the Unified Soil Classification System. Soil was sampled continuously for logging purposes with four foot long acetate sleeves removed from the direct push core barrel. Each soil sample for laboratory analysis was collected by cutting the acetate core barrel at the appropriate depth. The soil sample was then capped, labeled, stored in a cooler chilled with ice, and delivered to Argon Laboratories of Ceres, California for analyses. Logs for the borings with sampling depths, soil type encountered and other pertinent information are included in Attachment B. The soil samples were analyzed for TPH-G by EPA Method 8015B and for BTEX and gasoline oxygenates by EPA Method 8260B. The gasoline oxygenates included MTBE, ethanol, TBA, ETBE, DIPE, TAME, 1,2-DCA, and EDB. The detection limit for TPH-G was 1.0 mg/kg and ranged from 0.005 to 0.05 mg/kg for BTEX and the gasoline oxygenates. Groundwater was encountered in the borings at approximately 14 feet below grade. For each boring, the direct push tool was advanced to approximately two feet below the groundwater table (approximately 16 feet below grade). Once that depth was reached, the direct push tool was removed from the borehole and one-inch diameter PVC pipe with 0.020 slot screen was placed in the borehole to the total depth of the boring. Once groundwater entered the temporary well, groundwater was collected with a small-diameter, polypropylene bailer and gently poured into the appropriate sampling containers. The direct push sampling equipment was decontaminated between use at each boring by steam cleaning and rinsing with de-ionized water. Sample handling and laboratory analyses of the groundwater samples were in accordance with the procedures described above for the monitor well sampling. iM� CONDOR