Weekly Update Ending: April 08, 2011

National Grid’s Remediation Contractor and Project Team continued to plan for the third phase 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 performed perimeter privacy screen repairs, general maintenance activities and housekeeping 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 April 4, 2011 through April 10, 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.