Work on site week of January 25

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 commenced at the next Tent Position (i.e., Tent Position #14) with off-site transport and disposal of impacted soils at approved and permitted disposal facilities. In addition, the NYSDEC approved cut and cap operations were completed in the southwest part of the Site. Placement of imported clean backfill material commenced within the Tent Position #14 Shallow Excavation Area and continued at the two foot thick cap in the southwest 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. On January 27, 2010, the contractor placed the NYSDEC approved supplemental dust control measure, SoilTacTM, on non-traffic areas of the site. National Grid’s consulting engineers continued to monitor the site activities with the fixed base community air monitoring program (CAMP) equipment.

During the period from January 25, 2010 through January 31, 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. Elevated PM10 measurements were reported on January 25, 2010, January 28, 2010 and January 29, 2010; where these PM10 measurements were associated with high humidity readings on January 25, 2010 and gusty winds that transported imported clean backfill material from surface areas along the southern part of the site upwind of FAM 5 on January 28, 2010 and January 29, 2010. For all three events, the PM10 measurements were reported after remedial actions were completed for the day. Weekly Reports that summarize the CAMP data and the elevated measurements can be found as a separate tab in the Weekly Report Archive section.