ARCHIVED REPORTS XR0000667 - Laserfiche WebLink

Home Browse Search

' 09 May 2003 AGE-NC Project No 96-0232 Page 1 I of 16 ' xsoconcentration map displaying the estimated extent of dissolved MTBE In the area of the ground water extraction wells is depicted In Figure 8 ' No other constituents of concern were detected above laboratory reporting Ilmlts In the water samples collected during the first quarter 2003 sampling event Analytical results of ground water monitoring well samples are summarized m Tables 5 and 6 The laboratory reports (McCampbell ' Analytical Inc work order nos 0303416, 0303417 and 0303448) and chain-of-custody forms are presented in Appendix H ' 4.0. SUMMARY OF FINDINGS FROM QUARTERLY ACTIVITIES ' Previous soil characteristics data obtained by a CPT investigation enabled AGE to define five informal hydrologic units (Final Remediation Plan, dated 31 August 2000) The informal hydrogeologic units were defined as First Zone (10-35 feet bsg), Second Zone (40-60 feet bsg), ' Rocky's Upper Zone (65-75 feet bsg), Secondary Aquifer Zone (85-105 feet bsg), and Primary Aquifer Zone (130-150 feet bsg) The Rocky's Upper Zone was the shallowest ground water zone 10 screened In the destroyed Rocky's domestic drinking water well The results of pump and treat ground water remediation between 05 December 2002 and 25 March 2003 is as follows Approximately 2,871,250 gallons of MTBE-impacted ground water were extracted from wells EW-4, EW-5, EW-8, EW-9 and EW-10, which were completed in the First Zone ' aquifer(Appendix A, Table 8), due to a pump malfunction, well EW-8 was substituted for EW-5 between 27 January and 25 March 2003 A total volume of approximately 19,499,136 gallons of MTBE-impacted water has been treated at the site since the start-up period in ' November 2000 (Table 8) ® Dissolved MTBE was detected from grab samples collected at the Influent-end of the Itreatment system at concentrations between 21 µg/1 and 83 µg/l, laboratory analysis of grab water samples collected at the effluent-end of the pump and treat system did not detect any petroleum constituents of concern (Table 1) O Between 05 December 2002 and 25 March 2003, the mass of MTBE removed from the extracted ground water was calculated to be 0 86 pounds (Table 8, Appendix D) A plot of cumulative ground water pump and treat mass removal versus time and a plot of influent ground water MTBE concentrations versus time are included in Appendix E, during I the first quarter 2003, a general casual trend of increasing MTBE concentrations is evident for the first time since initiation of the ground water pump-and-treat system I Admneed GeoEuvsrenmenta3,Inc- 1