Weekly Update Ending: March 18, 2011

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. The Remediation Contractor demobilized the Casagrande Drill Rig elements loaded on flatbed trucks from the Site. In addition, the Remediation Contractor performed additional repairs of the wind-damaged perimeter privacy screen and general maintenance activities at the Site. No intrusive remediation construction activities were conducted at the Site. 

Maintenance of the imported backfill material (i.e., clean fill) stockpile covers 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 March 14, 2011 through March 18, 2011, six fixed base 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. 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 week of March 21, 2011 through March 25, 2011, general site maintenance and housekeeping will be performed, as necessary. No intrusive remediation construction activities are scheduled at the Site. Dust suppression activities will be conducted, as necessary. CAMP operation monitoring activities will continue. The specialty contractor procurement for the 120-foot deep Composite DNAPL Migration Barrier Wall Installation is scheduled to continue.