Weekly Update Ending: June 11, 2010

Filled truck leaving Tent Position 10A

National Grid’s Remediation Contractor continued with site remediation activities, which included the delivery of construction materials, imported backfill material (stone and common fill), as well as construction equipment and supplies. Site preparations continued for the installation of the 120-foot deep Composite DNAPL Migration Wall (Phase 3) in accordance with the NYSDEC-approved Field Change Request, FCR-06. Decontamination of the drill rig and equipment used in support of the FCR-06 designated Phase 1b pre-drill operations was completed. Installation of the upper 65-foot Waterloo BarrierTM interlocking steel sheet piling to the Site-Wide Cap subgrade elevation was also completed. On-site Waterloo BarrierTM interlocking steel sheet piling flushing and grouting operations continued. Site preparation activities continued in support of the Phase 1b Pre-Drill Activities waste management at Tent Position #10a which included the setup of the load-out stations (truck lining, scale, tarping, and decontamination pad).  Management of Phase 1b Pre-Drill Activities waste stockpiled inside Tent Position #10a commenced and included the off-site transport and disposal of impacted soils at approved and permitted disposal facilities. Common fill material deliveries and final grading and cap installation activities continued to progress in the central, eastern, and southeastern parts of the Site. Temporary sheet piling continued to be decontaminated, staged, and then loaded for demobilization from the Site. Additional 60-foot long Waterloo BarrierTM interlocking steel sheet piling was relocated and staged in the southwest corner 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, 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 June 7, 2010 through June 13, 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.

For the week of June 14, 2010 through June 18, 2010, cap material deliveries along with final grading and cap installation activities are scheduled to continue in the southeast part of the Site.  Site preparations will continue for the installation of the 120-foot deep Composite DNAPL Migration Wall (Phase 3) in accordance with the NYSDEC-approved FCR-06. Management of the Phase 1b Pre-Drill activities waste stockpiled inside Tent Position #10a and Tent Position #10a Shallow Excavation activities are scheduled for completion with off-site transport and disposal of impacted soils at approved and permitted disposal facilities. Flushing and grouting operations of the on-site Waterloo BarrierTM interlocking steel sheet piling will continue. Temporary sheet piling will continue to be demobilized from the Site. 

Odor and dust suppression activities will be conducted, as necessary.  Work zone delineation, site maintenance activities, CAMP operation monitoring activities as well as noise and vibration monitoring activities will continue.