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(YVAT-C A S S O C I A T E S I N C . feet below ground surface (bgs) to groundwater at a depth of approximately eet gs an within a radius of 35 feet from the former UST pit. In August 1993, wells MW-1, MW-2, and MW-3 were monitored and sampled. Analytical results showed that MW-1 had no measurable concentrations of petroleum hydrocarbons in the groundwater. Wells MW-2 and MW-3 contained detectable levels of petroleum hydrocarbons. A program of quarterly groundwater monitoring and sampling was begun in March 1994. In August 1995, Smith Technology conducted a subsurface site investigation to further define the extent of contamination in groundwater at the site. Smith Technology supervised the installation of monitoring wells MW-4, MW-5 and MW-6. These three new wells were developed and sampled along with monitoring wells MW-1, MW-2, and MW-3. Analytical results of groundwater samples from the six monitoring wells indicated the presence of elevated concentrations of petroleum hydrocarbons in the vicinity of wells MW-3 and MW-6, on the northeast comer of the site. In November 1998, ATC conducted a subsurface site investigation to evaluate the vertical and horizontal extent of hydrocarbon impacted soil. ATC supervised the installation of three soil borings SBI, S132, and SB3 from approximately 30 to 50 feet bgs. Analytical results of soil samples indicated the vertical extent of soil contamination had been defined, but the horizontal extent of impacted soil was not fully defined on the northeast corner of the site. Site activities are summarized in ATC's Summary Report of Additional Subsurface Investigation, dated January 27, 1999. WORKPLAN FOR GROUNDWATER EXTRACTION PILOT TEST Objectives and Scoae of Work ATC proposes to perform a 48-hour, low-rate pump test from monitoring well MW3. The objective of the pump test is to determine whether or not groundwater extraction will lower the concentrations of petroleum hydrocarbon constituents to acceptable levels over a reasonable time period. 48-Hour Groundwater Extraction Test ATC will notify PHS/EHD at least 48 hours prior to performing any fieldwork. Prior to beginning the pump test, ATC personnel will measure depth to water in all on-site wells and will collect one groundwater sample from well MW3. ATC will also collect one groundwater sample from well MW3 at the beginning of the test, mid-way through the test, and after the 48-hour pump test has been completed. The groundwater samples will be placed on ice and transported under chain-of-custody to a State-certified laboratory. Samples will be analyzed for TPHg and BTEX by EPA method 8015/8020 and for MTBE by EPA Method 8020. If MTBE is detected in any groundwater samples by EPA Method 8020, the sample will be analyzed for oxygenate fuel additives by EPA Method 8260 to confirm the results. W:\62605\REPORTS\WPPUMP.DOC 2