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1 In August 1993, wells MW-1, MW-2, and MW-3 were monitored and sampled. Analytical results <br /> showed that MW-i had no measurable concentrations of ,petroleum hydrocarbons in the <br /> groundwater. Wells MW-2 and MW-Tcontained detectable levels of petroleum hydrocarbons. A <br /> p program of quarterly groundwater monitoring and sampling was begun in March 1994. <br /> In August 1995, Smith Environmental conducted a subsurface site investigation to further define the <br /> extent of contamination in groundwater at the site. Smith Environmental supervised the installation of <br /> monitoring wells MW4, MW-5 and MW-6. These three new wells were developed and sampled <br /> along with monitoring wells MW-I, MW-2, and MW-3. Analytical resultsof groundwater samples <br /> from the six monitoring wells indicated the presence of elevated concentrations of petroleum <br /> hydrocarbons in the vicinity of wells MW-3 and MW-6, on the northeast comer of the site. <br /> PROPOSED SCOPE OF WORK <br /> Smith Environmental proposes the following scope of work to evaluate uate potential groundwater <br /> contamination at the subjecb site. <br /> Installation of Two Groundwater Wells and Three Vapor Wells <br /> This task includes mobilization to the site, advancing two soil borings off-site and completing <br /> them as groundwater monitoring .wells, and then advancing .three soil borings on-site and <br /> completing them as vapor wells. The proposed locations of the groundwater and vapor wells are <br /> shown on Figure 2. <br /> The two off-site borings will be advanced to depths of 40 feet below ground surface (bgs), and <br /> the three on-site borings will be advanced to depths of 30 feet bgs using 8-inch O.D. hollow stem <br /> augers. Drilling will be conducted by Spectrum Exploration, Inc., a State-licensed (C57) drilling <br /> company. A field geologist will be present to log all drill cuttings and soil samples. Descriptions <br /> of soil types encountered, sample collection intervals, and well construction details will be <br /> recorded on boring/well logs. Soil samples will be collected at five foot intervals and up to two <br /> samples from each boring will be submitted for laboratory analysis of total petroleum <br /> hydrocarbons as gasoline(TPHg) and benzene, toluene, ethylbenzene, and xylenes (BTEX). <br /> Selected soil samples will be sent using chain-of-custody record to a State-certified laboratory for <br /> analysis of TPHg and BTEX. The two off-site borings, will be completed as groundwater <br /> monitoring wells with screened intervals from approximately 25 to 40 feet bgs, and the three on- <br /> site borings will be completed as vapor wells with screened intervals from approximately 10 to 30 <br /> feet bgs. The wells will be constructed of 2-inch inside diameter PVC well screen and casing. To <br /> protect the integrity of the wells,locking, water-tight well plugs will be installed on each well, and <br /> water-tight, traffic rated, wellheads labeled "monitoring well" will be concreted over each well. <br /> All drill cuttings will be drummed and stored on-site pending,laboratory results. <br /> w:\94373\,epoRc\wp0496.dM 2 <br /> SMTH <br />