The objectives listed in Table 1.1 were accomplished with the exception of one well.  All wells scheduled to be sampled for the June event were sampled with the exception of FO-J1.  This well could not be sampled because of an electrical malfunction of the breaker box at the well.

Fifteen of the thirty-two wells sampled reported detections of VOCs in June 2004.  Of the wells with VOC detections, two wells had concentrations above the MCL for PCE.  Well RFR-10 had a detection of 6.31 �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 2.93 �g/L, above the RL, and cis-1,2-DCE at a concentration 0.55 �g/L, below the RL.  Well OFR-3 reported PCE above the MCL at a concentration of 5.02 �g/L, TCE above the RL at a concentration of 2.48 �g/L, and dichlorodifluoromethane above the MDL at a concentration of 0.80 �g/L.  Both of these wells were previously equipped with GAC filtration systems.

Six wells had detections of VOCs reported at concentrations below the MCL, but above the RL for one or more of chloroform, PCE, and TCE/PCE was detected above the RL in LS-2, LS‑6, and LS-7; TCE above the RL in OFR-3 and RFR-10; and chloroform above the RL in JW-14.  Wells LS-2/LS-3, LS-6, LS‑7, RFR-11, and OFR-3 have been equipped with GAC filtration systems.  Well JW-14 had concentrations of chloroform above the RL and bromodichloromethane below the RL.  These concentrations were below the applicable MCLs.

Fifteen 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, dibromo-chloromethane, dichlorodifluoromethane, and toluene.  These analytes were detected in samples I10-2, JW-7, JW-14, JW-28, LS-2, LS-3, LS-4, LS-6, LS-7, OFR-1, OFR-2, OFR-3, RFR-10, RFR-11, RFR-12, and the field duplicate, collected at RFR-12.

Seventeen wells had no detections from the short list of VOCs:  FO-17, the field duplicate of FO-17, HS-2, HS-3, I10-4, I10-7, JW-6, JW-8, JW-9, JW-13, JW-26, JW-27, JW‑29, JW-30, LS-1, the field duplicate of LS-1, LS-5, RFR-3, and RFR-8.

PCE concentrations decreased between March 2004 and June 2004 in wells HS-2, I10-4, JW-8, JW-9, LS-1, LS-6, LS-7, OFR-1, OFR-2, and RFR-10.

TCE concentrations decreased in wells I10-4, LS-5, LS-6, LS-7, RFR-10, and RFR‑11.

PCE concentrations increased in wells I10-2, JW-7, LS-2, LS-3, LS-4, OFR-3, and RFR-11.

TCE concentrations increased in wells I10-2, LS-2, LS-3, OFR-3, and RFR-12.

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 September 2004 event.

Wells 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 June 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 (I10-2, JW-7, JW-14, JW-28, LS-2, LS-3, LS-4, LS-6, LS-7, OFR-1, OFR‑2, OFR-3, RFR-10, RFR-11, and RFR-12) in June 2004 will continue to be sampled on a quarterly basis, including the September 2004 event in accordance with Plan requirements.  Depending on concurrence by regulatory agencies, the sampling frequency may then be reduced.

Post-GAC confirmation samples will be collected at all off-post wells with GAC systems during the September 2004 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 September 2004, wells where no VOCs were detected may be sampled as needed, depending on historical detections.  June 2004 wells with no VOCs detected include FO-17, HS-2, HS-3, I10-4, I10-7, JW-6, JW-8, JW-9, JW-13, JW-26, JW-27, JW-29, JW-30, LS-1, LS-5, RFR-3, and RFR-8.

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 September 2004 is provided in Table 4.1.