Decontamination of truck prior to moving offsite

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 at Tent Position #13 with off-site transport and disposal of impacted soils at approved and permitted disposal facilities.  Placement of imported clean backfill material and compaction was completed within the Tent Position #13 Shallow Excavation Area.   Tent relocation activities from Tent Position #13 east to the next Tent Position (Tent Position #12) were completed. Tent relocation activities included 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 were reset as the final phase of the tent position relocation. Cap material deliveries and final grading and cap installation activities commenced in the western part of the site.    National Grid’s consulting engineer conducted noise and vibration monitoring activities, as necessary.

Compaction of backfill soil

During the period of March 12, 2010 through 13, 2010, the storm event damaged the temporary enclosure fabric panels, the site fence and power lines adjacent to the Site.  The National Grid project team is currently planning and scheduling the necessary repairs. Since remedial excavation activities in Tent Position #13 and the Tent Position # 12 relocation activities were completed on Friday, March 12, 2010, no contaminated soil was exposed.

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 community air monitoring program (CAMP) equipment.

During the period from March 8, 2010 through March 14, 2010, 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 readings were reported for the weekly monitoring period. The Weekly Report that summarizes the CAMP data can be found as a separate tab in the Weekly Report Archive section.