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 performed repairs to the Site perimeter screen to address damage resulting from the Hurricane Irene storm event, and conducted general maintenance and housekeeping activities. In addition, the Contractor commenced the mobilization of personnel and equipment to conduct initial 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 5, 2011 through September 11, 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.

For the week of September 12, 2011 through September 16, 2011, Phase 3 remediation construction activities are scheduled to commence at the Site. The remediation contractor is scheduled to excavate into the clean backfill material and construct the foundations for the proposed Phase 3 Grout Plant silos. The Remediation Contractor will continue with the mobilization of personnel and equipment, and will conduct Site preparations and detailed layout efforts for the Phase 3 Composite 120-foot deep DNAPL Migration Barrier Wall Installation project. In addition, the contractor will conduct general maintenance activities and housekeeping at the Site, as necessary. Dust suppression activities will be conducted, as necessary.   CAMP operation monitoring activities will continue.