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' 4mlogtralredudcslne. • Page Work Plan George's Service ' Project No.425.2 September 26,2007 Since only selected soil samples collected will be submitted for laboratory analysis, a screening process will be used to gather additional information through field observation. ' These observations include: • sediment type, especially grain size and clay content • moisture content ' • visible evidence of contamination, i.e., color change due to reduction of iron or discoloration from hydrocarbons and other pollutants • readings above background on a organic vapor meter(OVM) 1 The OVM is a portable photo ionization detector that uses a 10.0 eV lamp to detect compounds with ionization potential below 10.0 eV (hydrocarbon range). 1 2.1.2 Soil Laboratory Analyses Groundwater samples from each monitoring well will be submitted to a state certified ' laboratory for the following analysis: • BTEX by EPA method 8020 • MTBE by EPA method 8020 ' • TPH-G by EPA method 8015(m) ' 2.1.3 Monitoring Well Construction The monitoring wells will be constructed using 2.0-inch diameter PVC casing with flush threads. A short screen (2.5-feet in length) will be used. A #3 sand filter pack will surround and extend two feet above the 0.020 inch screened interval. A weighted bentonite pellet seal will be installed. A surface seal of neat cement grout (augmented with < 4% bentonite) will be installed via a tremie pipe. The wells will be secured with locking watertight caps encased ' in flush mounted traffic rated well boxes. Construction details are as follows: Well No. DiaJ'1'D Screen Slot Sand Pack Trans.Seal Grout Seal SW-101 2'/37.5' 32.5-35' 0.020" #3 sand 30-37.5' 28-30' 28-surface SW-102 2"/37.5' 32.5-35' 0.020" #3 sand 30-37.5' 28-30' 28-surface This is the same construction as MW-106. Figure 3 is a schematic of monitoring well ' construction. However, it is noted that if this sand unit is found at a different depth, we will adjust the well construction accordingly. ' After the well sealing materials have set (>24 hours) the well will be developed (using mechanical surging and pumping methods) until a clear stream of water is obtained. The well will be purged and groundwater samples collected no sooner than 48 hours after well development. All development and purge water will be containerized in 55-gallon DOT approved containers and stored on site until their disposition can be arranged.