National Grid’s Remediation Contractor and Project Team continued to plan for the composite 120-foot deep dense non-aqueous phase liquid (DNAPL) Migration Barrier Wall (i.e., jet grouted barrier) installation. The Remediation Contractor continued with general maintenance of the Site, excavated into the clean backfill material and constructed the foundations for the proposed Phase 3 Grout Plant silos. The Remediation Contractor continued with the mobilization of personnel and equipment, and conducted Site preparations and detailed layout efforts for the Phase 3 Composite 120-foot deep DNAPL Migration Barrier Wall Installation project.  No intrusive remediation construction activities were conducted at the Site. The jet grouting contractor (JGC) and waste management and emergency response (WM/ER) contractor were involved with the final procurement, preparation of pre-mobilization submittals, and scheduling activities for the project.

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 September 12, 2011 through September 18, 2011, six fixed base CAMP units were in operation 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.