National Grid’s Remediation Contractor continued with site remediation activities, which included the delivery of construction materials, imported backfill material (stone and common fill), and construction equipment and supplies. Shallow Excavation Area remedial activities continued at Tent Position #5 with off-site transport and disposal of impacted soils at approved and permitted disposal facilities. Placement of imported clean backfill material also continued within the Tent Position #5 Shallow Excavation Area. On-site concrete crushing operations continued in the western part of the Site with reuse as backfill for the Tent Position # 5 Shallow Excavation Area.  Installation of the 120-foot deep section of the On-Site DNAPL Barrier Wall continued along the northern part of the site.  National Grid’s consulting engineer conducted noise and vibration monitoring activities, as necessary.

Maintenance of the decontamination areas, work zones, on-site gravel access roads, parking areas and material staging areas, the 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 fixed base community air monitoring program (CAMP) equipment, as well as with noise and vibration monitors.

During the period from October 19, 2009 through October 25, 2009, 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. No elevated TVOC and PM10 measurements were reported for the weekly CAMP monitoring period. Weekly Reports of the CAMP data can be found as a separate tab in the Weekly Report Archive section.

For the week of October 26, 2009 through October 30, 2009, Tent Position #5 Shallow Excavation activities are scheduled to be completed with off-site transport and disposal of impacted soils at approved and permitted disposal facilities. Delivery of imported clean backfill material (stone and common fill) and backfill material placement inside Tent Position #5 will continue. On-site concrete crushing operations will continue in the western part of the Site with reuse as backfill for Tent Position # 5 and future tent positions Shallow Excavation Area.   Installation of the 120-foot deep section of the On-Site DNAPL Barrier Wall is scheduled to continue.  Odor and dust suppression activities will be conducted as necessary. Work zone delineation, site maintenance activities, CAMP operation, and noise and vibration monitoring activities will continue.

In response to requests from the community, National Grid has instructed its trucking contractors to reinforce directions to all drivers that they must comply with local speed limits and refrain from using air brakes while transporting materials along the approved truck route.