Laserfiche WebLink
13 April 2001 <br /> AGE-NC Project No 96-0232 <br />' Page 13 of 14 <br />' in First Zone ground water at the site <br /> AGE estimates the arithmetic average concentration of MTBE in ground water extracted between <br />' 01 January and 31 March 2001 was 164 ,ccg/l The total volume of water processed through the <br /> ground water pump and treat system was recorded at 2,474,726 gallons (equivalent to 20,631,791 <br /> pounds) of water extracted yields 3 4 pounds of MTBE (equivalent to 1,542 grams) removed from <br />' the plume of impacted ground water(Appendix E), or approxunately 17 grams per day <br />' Analytical results from the March 2001 quarterly monitoring event indicates the most intense on-site <br /> MTBE impact is in the First Zone near EW-4(540/.cg/1) and in the Second Zone near MW-9A (680 <br /> ,ug/l),the most intense offsite MTBE impact is in Second Zone of MW-11A(210,ug/l) and Rocky's <br />' Upper Zone of MW-11B (240 yg/1),probably influenced by the pumping operation of RDW-1 <br /> Significant concentrations of MTBE were quantified west of the site in the area of Three B's Truck <br /> Plaza wells MW-4, MW-6 and Flag City Chevron wells MW-7 MW-13A which suggest the <br /> possibility of separate MTBE plumes being pulled towards domestic drinking water wells RDW-1 <br /> and DW-1 (Figure 7) <br /> Ground water elevations versus ground water monitoring dates (hydrograph) were plotted for <br /> monitoring wells MW-2, MW-6A and MW-6B, generally, all three plots depicted a trend of <br /> decreasing ground water elevations from May 2000 to August 200, however ground water elevations <br /> did show an mcrease from August 2000 to March 2001 (Appendix J) <br /> 6.0 RECOMMENDATIONS <br /> IBased upon data collected from the site, AGE recommends <br /> • Continued quarterly ground water monitoring and sampling of monitoring wells MW-1 <br /> through MW-13, municipal water wells CSA-1 and CSA-2 and domestic water wells DW-1 <br /> and RDW-1 <br /> a Continued coordinated quarterly ground water sampling events with Three B's Truck Plaza <br /> • Installation of fuel-dispenser containment pans beneath each fuel dispenser at the Flag City <br /> I Chevron site <br /> • Continued selective ground water extraction in alternating weekly shifts from extraction <br /> wells located in the south trench-line (EW-2, EW-4, EW-6 and EW-9) and wells located in <br /> the north trench-line (EW-5, EW-7, EW-8 and EW-10) <br /> • Elimination of analysis for methanol, ethanol, 1,2-DCA and EDB from the quarterly ground <br /> Advanced GeoEnv=ronmental,Inc. <br /> I <br />