Extracting Temporary Sheeting from excavated area.

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. Further, placement of imported clean backfill material was completed within the Tent Position #4 Shallow Excavation Area. On-site concrete crushing operations continued and temporary steel sheeting installations continued in the southwest corner of the site. After Tent Position #4 backfill placement activities were completed, the temporary fabric enclosure and Vapor Management System (VMS) system was relocated to the west from Tent Position #4 to Tent Position #5. 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 September 28, 2009 through October 4, 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 or 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 5, 2009 through October 9, 2009, Tent Position #5 Shallow Excavation activities are scheduled to commence 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 commence. On-site concrete crushing operations are scheduled to continue this week in the western part of the Site. Installation of the 120 foot deep On-Site DNAPL Barrier Wall will commence on October 5, 2009.   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.