ARCHIVED REPORTS XR0001191 - Laserfiche WebLink

Home Browse Search

Mr John Benedict Project No 880-039 IA July 25, 2002 Page 2 collected from subsurface investigations performed at the former ARCO Service Station, Chevron Station, and Texaco Station (located at the corners of Charter Way and Lincoln Street), residual and dissolved hydrocarbons have been detected beneath these facilities ' Between September 17 and October 11, 1996, EMCON/OWT observed the drilling of six soil borings (B-1 R through B-6R) One soil boring was converted to monitoring well MW-I R, three ' soil borings were converted to dual completion vapor extraction wells VW-1 through VW-3, and one soil boring was converted to a single vapor extraction well VW-4 (EMCON, Preliminary Investigation and Evaluation Report, February 5, 1997) The results of this investigation indicated the following 1 + With the exception of soil samples collected from boring B-6R, residual hydrocarbons were detected in each boring The highest concentrations were detected approximately 10 feet below ground surface (bgs) near the former USTs Total oil and grease were detected in the soil sample collected near the former UST cavity (located near the building) at a concentration of 10,000 parts per million Polychlorinated biphenyls, TPH-d, and chlorinated hydrocarbons were below laboratory detection limits in all soil samples analyzed from soil borings B-2R and MR ! • TPH-g, benzene, toluene, ethylbenzene, and total xylenes (BTEX), and methyl tert- butyl ether (MTBE) were detected in the groundwater sample collected from ! monitoring well MWAR TPH-g and benzene were detected at concentrations of 33,000 parts per billion (ppb) and 1,400 ppb, respectively MTBE was detected at a concentration of 550 ppb GROUNDWATER MONITORING SECOND QUARTER 2002 mai t3l� On 002 a Shaw E & I technician was on-site to measure depth to groundwater and collect groundwater samples from wells MW-1R, VW-2, VW3, and VW-4 for subjective and laboratory analyses Shaw E & I has attempted to coordinate Joint quarterly sampling with the former ARCO Facility 2168, located east and downgradient of the subject site, but has not gotten a response from their consultant Floating product has not observed in groundwater momtoring wells (see Table I and Appendix A) Shaw E& I used the second quarter 2002 data to evaluate changes in concentrations of dissolved gasoline hydrocarbons in the groundwater Shaw E & I sampling and analysis procedures are presented in Appendix B \\SAC RFP]1COM M ON1sac DP120021P RJNPJ 8188018800391 A 2ae doc