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 were completed on December 8, 2009 at Tent Position #7 with off-site transport and disposal of impacted soils at approved and permitted disposal facilities. Placement of imported clean backfill material and compaction were completed on December 10, 2009 within the Tent Position #7 Shallow Excavation Area.  Installation of temporary sheet piles continued at planned tent positions along the northern perimeter 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 December 7, 2009 through December 13, 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. PM10 measurements above the Action Level were reported on December 10, 2009 and December 11, 2009; where these PM10 measurements were not associated with ground intrusive activities. Weekly Reports of the CAMP data can be found as a separate tab in the Weekly Report Archive section.

For the week of December 14, 2009 through December 18, 2009, Tent Position #7 will be relocated west to Tent Position #8. Tent relocation activities will include the temporary disassembly and staging of tent anchors and the vapor management system (VMS), temporary removal of the central panel, end panels and access doors, followed by the relocation of the two tent sections and replacement of the central panel, access doors, and end panels.  The temporary fabric enclosure supports, tent anchors, and VMS will be reset as the final phase of the tent position relocation. Tent Position #8 Shallow Excavation activities are scheduled to commence this week 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 #8 are scheduled to commence.  On-site concrete demolition, crushing, and reuse operations are scheduled to continue at the Site, as necessary. Installation of temporary sheet piles will continue at planned tent positions along the northern perimeter of the Site.  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.