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Mr. Doug Schneeberger 2 May 17, 1995 Monitoring wells were purged a minimum of three static well volumes of water using dedi- cated, laboratory-cleaned, stainless steel bailers. The volume of water purged from each monitoring well and field measurements of pH, specific conductance, and temperature are documented in the well purging sheets presented in Attachment 1. Immediately following the purging of each monitoring well, a ground water sample was collected and placed in the ap- propriate containers in accordance with industry standard sampling protocols. The sample aliquot for dissolved metals analysis was field-filtered through a 0.45-micron filter prior to sample preservation. Quality assurance/quality control (QA/QC) samples, collected during this sampling round, consisted of one duplicate sample at Monitoring Well MW-1 (RTI- MW1D-0395), an equipment rinsate blank (RTI-RBO1-0395) and a trip blank (RTI-TB01- 0395). Ground water samples and QA/QC samples were submitted to the Pace, Inc., of Petaluma, California, laboratory for analysis of benzene, toluene, ethylbenzene, and total xylenes (BTEX) by U.S. Environmental Protection Agency (EPA) Method 602-8015M, total petroleum hydrocarbon (TPH)-purgeable fuels-as-gasoline range by EPA Method 602- 8015M, and dissolved lead and chromium by EPA Method 200.7. The trip blank sample was analyzed only for BTEX. GROUND WATER ANALYSIS RESULTS A summary of the ground water analytical results is presented in Table 2, and the laboratory analytical report is included as Attachment 2. BTEX and TPH-Gasoline Analyses The analysis of ground water samples collected during the first quarter indicated the presence of BTEX constituents in the samples collected from Monitoring Wells MW-1 and MW-6. The ground water sample collected from Monitoring Well MW-1 detected individual BTEX constituent concentrations of 8,600, 5,700, 1,800, and 5,600 micrograms per liter (µg1f), re- spectively (Table 2). The analysis of the ground water sample collected from Monitoring Well MW-6 indicated only the presence of ethylbenzene and total xylenes at concentrations of 8.1 and 17 jtg1C, respectively. The remaining ground water samples (i.e., samples from Monitoring Wells MW-2, MW-3, MW-4, and MW-5) indicated no detectable concentrations above practical quantitation limits (PQLs) of 0.3 µg/f for benzene, toluene, and ethylben- zene, and 0.6 µglf for total xylenes. The PQLs for the ground water sample collected from Monitoring Well MW-1 were elevated to 60 jcg/f for benzene, toluene, and ethylbenzene, and 120 µg1 f for total xylenes. TPH-purgeable fuels-as-gasoline were detected above the PQL of 500 µg11' only in the ground water samples collected from Monitoring Wells MW-1 and MW-6 at concentrations of 50,000 and 2,300 jsg/f, respectively (Table 2). The PQL for the sample from Monitoring :30091 - "REALISTIC SOLUTIONS FOR HAZARDOUS WASTE PROBLEMS"