National Grid’s Remediation Contractor and Project Team continued to plan for the third phase (Phase 3) of the 120-foot deep dense non-aqueous phase liquid (DNAPL) Migration Barrier Wall installation. Phase 3 will consist of the installation of a deep jet grouted barrier wall to complete the 120-foot deep Composite DNAPL Migration Barrier Wall Installation.  No remediation construction activities were conducted at the Site.

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 December 13, 2010 through December 19, 2010, six fixed base CAMP units and one portable CAMP unit 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. There were no elevated readings for TVOC or PM10 for this monitoring period.   The Weekly Report that summarizes the CAMP data can be found as a separate tab in the Weekly Report Archive section.

For the holiday week of December 20, 2010 through December 24, 2010, no remediation construction activities are scheduled at the Site. Dust suppression activities will be conducted, as necessary. Site maintenance activities and 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.