The objectives listed in Table 1.1 were accomplished with the exception of one well.  All wells scheduled to be sampled for the September event were sampled with the exception of LS-1.  This well is offline due to well owners� complaints of cloudy water.

Twenty of the twenty-six wells sampled reported detections of VOCs in September 2004.  Of the wells with VOC detections, one well had concentrations above the MCL for PCE and TCE.  Well RFR-10 had a detection of 18.76 �g/L PCE, which exceeds the MCL of 5.0 �g/L.  Well RFR‑10 also had a detection of TCE at a concentration of 7.99 �g/L, also above the MCL, and cis-1,2-DCE at a concentration 0.43 �g/L, below the RL.  This well was previously equipped with a GAC filtration system.

Six wells had detections of VOCs reported at concentrations below the MCL, but above the RL for one or more of PCE, TCE and toluene.  PCE and TCE were detected above the RL in OFR-3 and RFR-11; PCE was detected above the RL in wells LS-2, LS-3, LS‑6, and LS-7; toluene above the RL in LS-3.  Wells LS-2/LS-3, LS-6, LS‑7, RFR-11, and OFR-3 have been equipped with GAC filtration systems.

Twelve wells reported concentrations of VOCs above the MDL, but below the RL for one or more of the following analytes:  PCE, TCE, cis-1-2-DCE, bromodichloromethane, chloroform, dibromo-chloromethane, dichlorodifluoromethane, and toluene.  These analytes were detected in samples FO-J1, HS-2, I10-2, I10-2 (FD), I10-4, JW-8, JW-14, JW-28, JW-28 (FD), LS-4, LS-5, OFR-1, OFR-1 (FD), OFR-2, and RFR-12.

Six wells had no detections from the short list of VOCs:  JW-9, JW-26, JW‑29, JW-30, RFR-3, and RFR-9.

PCE concentrations decreased between June 2004 and September 2004 in wells FO-J1, JW-7, LS-2, LS-4, OFR-1, and OFR-3.

TCE concentrations decreased in wells I10-2, LS-6, OFR-3, and RFR‑12.

PCE concentrations increased in wells HS-2, I10-4, JW-8, JW-14, LS-3, S-2/LS-3-A1, LS-6, LS-7, OFR-2, RFR-10, and RFR-11.

TCE concentrations increased in wells LS-3, LS-2/LS-3-A1, LS-5, LS-7, RFR-10, and RFR-11.

Post GAC samples were collected from wells (LS-2/LS-3, LS-6, LS-7, OFR-3, RFR-10, and RFR-11).  All post GAC samples reported no VOC with the exception of the post GAC samples collected from wells LS-2/LS-3.  The samples collected between the canisters (LS-2/LS-3-A1) reported PCE and TCE below the RL and the samples collected after both carbon canisters reported chloroform below the RL.  Due to the slight VOC breakthrough maintenance is scheduled to be preformed on this GAC unit.

In accordance with Plan requirements, wells with historical detections above 90 percent of the applicable MCL (LS‑2, LS-3, LS-6, LS-7, OFR‑3, RFR-10, and RFR‑11) will continue to be sampled on a quarterly basis, including the December 2004 event.

Wells without GAC systems and with detections above 80 percent of the applicable MCLs are required to be sampled on a monthly basis in accordance with the Plan.  No wells sampled during the September 2004 event will be sampled monthly.  All wells with VOC detections greater than 80 percent of the applicable MCLs have GAC filtration systems installed and are already included in the quarterly monitoring.

Wells with detections of VOCs at less than 80 percent of the MCLs (FO-J1, HS-2, I10-2, I10-4, JW-7, JW-8, JW-14, JW-28, LS-2, LS-3, LS-4, LS-5, LS-6, LS-7, OFR-1, OFR‑2, OFR-3, RFR-10, RFR-11, and RFR-12) in September 2004 will continue to be sampled on a quarterly basis, including the December 2004 event in accordance with Plan requirements.  Depending on concurrence by regulatory agencies, the sampling frequency may be reduced.

Post-GAC confirmation samples will be collected at all off-post wells with GAC systems during the March 2005 sampling event.  This will include wells LS-2, LS‑3, LS-6, LS-7, OFR‑3, RFR-10, and RFR-11.

For future sampling events, including December 2004, wells where no VOCs were detected may be sampled as needed, depending on historical detections.  September 2004 wells with no VOCs detected include JW-9, JW-26, JW-29, JW-30, RFR-3, and RFR-9.

In the event additional wells are located to the west and southwest of CSSA, they may be added to future sampling events.  Future sampling events will continue to include wells to the west of CS-D and CS-MW16-LGR (Fair Oaks and Jackson Woods areas) to confirm they continue to meet drinking water standards.

In accordance with project DQOs, the rationale for selection of wells to be sampled in December 2004 is provided in Table 4.1.