National Grid’s Remediation Contractor continued with the imported backfill material deliveries, grading activities, and Cap construction.  The remaining anchor ballasts and VMS were reset as part of the final phase of the tent position relocation activities prior to the start of the Phase 3 field operations. The National Grid Project Team continues to plan for the third phase (Phase 3) of the phased 120-foot deep dense non-aqueous phase liquid (DNAPL) Migration Barrier Wall installation. Phase 3 will consist of the installation of a deep soil-cement barrier wall to complete the 120-foot deep composite DNAPL Migration Barrier Wall installation. Temporary sheet piling removal, decontamination, and on-site staging for re-use or for future demobilization continued.

Maintenance of the decontamination areas, work zones, on-site gravel access roads, parking areas and material staging areas, imported backfill material (i.e., clean fill), stockpile covers, the perimeter privacy screen, and soil erosion and sediment control (SESC) measures continued. Odor and dust suppression activities were conducted, as necessary. National Grid’s consulting engineers continued to monitor the site activities with the community air monitoring program (CAMP) equipment.

During the period from September 27, 2010 through October 3, 2010, six fixed base CAMP units and two portable CAMP units were in use and measured total volatile organic compounds (TVOC) and particulates (PM10). Fifteen-minute averages for both TVOC and PM10 data remained in the Operational Condition during work activities.  On Sunday, October 3, 2010 there was a period of elevated PM10 concentrations at Fixed Air Monitoring Site 4 (FAM 4); where the cause of the elevated concentrations is unknown. No on-site work activity occurred during this short duration period of elevated concentration.  The Weekly Report that summarizes the CAMP data can be found as a separate tab in the Weekly Report Archive section.

For the week of October 4, 2010 through October 8, 2010, imported backfill material deliveries, grading activities, and Cap construction are scheduled to continue.  Odor and dust suppression activities will be conducted, as necessary.  Work zone delineation, site maintenance activities, CAMP operation monitoring activities will continue, as necessary.  The specialty contractor procurement for the 120-foot deep composite DNAPL Migration Barrier Wall installation is scheduled to continue.