Laserfiche WebLink
1 <br /> 26 February 1996 <br />' AGE-NC Project No 95-0125 <br /> Page 2 of 6 <br />' 2 3 MONITORING WELL INSTALLATION AND SAMPLING <br />' Between 1987 and 1992, a total of ten ground water monitoring wells were installed at the site by <br /> Groundwater Technology, Inc (GTI) No petroleum hydrocarbons were detected in soil samples <br /> collected during installation of the wells <br /> Ground water was sampled on eight occasions between 1987 and 1995 Field observation of selected <br /> monitoring wells were performed on an infrequent basis between 1993 and 1994 by representatives <br />' of LSD Historical groundwater depth at the site has varied between 5 and 10 feet below surface <br /> grade (bsg) Ground water flows toward the northwest <br />' Petroleum hydrocarbons have been detected in ground water only in the vicinity of the former <br /> dispensers Previous sampling events have established an ellipse-shaped ground water plume, <br /> extending from MW-2 at the south to near MW-5 at the north The center of the plume has <br />' apparently remained near MW-6 (GTI report dated 3 March 1992) <br /> 2 4 LIMITED SUBSURFACE INVESTIGATION <br />' On 26 June 1995, five soil probe borings were advanced at the site to a depth of ten feet bsg <br /> Discrete soil samples were collected at depths of five, seven and ten feet bsg In addition to soil <br /> samples, a grab ground water sample was obtained from one probe boring Petroleum hydrocarbons <br />' were detected in soil samples collected during the investigation Results of the investigation were <br /> detailed in a report dated 25 September 1995, prepared by AGE <br /> 3.0. PROCEDURES <br /> 3 1 MONITORING WELL PURGE PROCEDURES <br /> On 19 October 1995, the depth to ground water in each well at the site was measured relative to the <br /> casing top using a Solinst water level meter The relative ground water elevation in each well and <br /> prevailing hydraulic gradient were deternuned from these data Ground water depth data is presented <br /> in Table 1 <br /> After depth to water measurements were collected, a submersible pump was used to remove <br /> approximately 5 gallons of standing water from wells MW-5 and MW-6 to stabilize temperature, pH <br /> rand conductivity Stabilization of these parameters demonstrates proper purging of the well Due to <br /> a low volume of standing water in MW-2, only one gallon of water was removed Stabilization <br /> I parameters were measured at one-gallon intervals using an ICM Water Analyzer Purged water was <br /> stored on-site in DOT drums Ground water stabilization and field data sheets are included in <br /> Appendix A <br />