ARCHIVED REPORTS XR0009496 - Laserfiche WebLink

Home Browse Search

1 y AZURE ENVIRONMENTAL ' Water table elevation data collected at the Site indicate the general direction of ground-water flow IS toward the northeast, with local variations of flow direction in the area adjacent to the former tank locations at the Site (Figure 3) These data are generally consistent with potentiometnc data ' and interpretations of ground-water flow direction at the Site presented in previous investigation reports Shallow ground water in the site vicinity flows toward the northeast under a hydraulic gradient of approximately 0 001 ft/ft ' 3.2 Ground-Water Sampling and Laboratory Analysis ' On February 13, 1997, ground-water samples were collected from two downgradient monitoring wells at the Site (MW-9 and MW-10) Historical laboratory analysis results are summarized in Table 3, laboratory certificates are included in Appendix A and field sampling data sheets are ' included in Appendix B Most recent ground-water monitoring data are illustrated in Figure 4 Morutoring data collected for wells MW-9 and MW-10 in March 1997 indicate petroleum ' hydrocarbons, including benzene (<0 5 ppb) and MTBE (<50 ppb), were not detected These data are generally consistent with lustorical monitoring results, which indicate benzene has not been detected at MW-9 since January 1995 (0 6 ppb) and at MW-10 since October 1994 (0 6 tppb) These data continue to indicate the petroleum hydrocarbon plume has stabilized and is restricted to shallow ground water in the area adjacent to the former tank locations at the Site 4.0 TECHNICAL STATUS REPORT ' Work Completed During the Januafy through March 1997 Work completed during the previous quarter included performance of the quarterly ground-water ' monitoring program In the report entitled"Soil Sampling Results and Recommendation for Soil Treatment Cell Closure" dated December 26, 1996, Azure recommended that no further remedial actions for treatment cell soil at the Site were necessary and that the treatment cell should be approved for closure In a telephone conversation with Mr Harlan Knoll of the SJCPHS on February 12, ' 1997, Mr Knoll indicated that he reviewed our sampling report and concurred with our plan to close the treatment cell Mr Knoll requested that we notify hum of plans to dismantle and grade the soil treatment cell area prior to conducting the work Mr Knoll indicated that he would send ' a confirming letter stating his concurrence with our recommendation within the next few weeks Work Expected to be Completed During the April through June 19�uarterly Period ' Work expected to be completed during the next quarter includes continued performance of the ' quarterly ground-water monitoring program A Workplan for Site Closure is expected to be submitted to the SJCPHS during the next quarterly period The Workplan will outline the work tasks and schedule for evaluating closure criteria and ' 2