Tent frame being removed from site

National Grid’s contractor and Project Team completed the construction of the composite 120-foot deep dense non-aqueous phase liquid (DNAPL) Migration Barrier Wall (i.e., jet grouted barrier) in April 2012. The Jet Grouting Contractor (JGC) completed the decommissioning and demobilization of construction equipment, supplies and materials, while the Waste Management (WM) contractor continued this process. In addition, the WM contractor completed the decommissioning of the Waste Management Facility (WMF) and Vapor Management System (VMS), and the disassembly and load out / demobilization of the temporary enclosure structure (tent). Further, the WM contractor completed the load-out of the remaining jet grouting derived solids (scrapes), wastewater, and storage tanks during this period. The air handling system (four TIGG units) was partially demobilized, as two of the four TIGG units were demobilized from the site.

General maintenance and security activities also continued at the Site. Contractor demobilization of construction equipment and materials commenced. Maintenance of the imported backfill material (i.e., clean fill) stockpile covers 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 4, 2012 through June 10, 2012, six fixed base CAMP units were in operation and measured particulates (PM10). Fifteen-minute averages for PM10 data remained in the Operational Condition. There were no elevated readings for PM10 for this monitoring period. The Weekly Report that summarizes the CAMP data can be found as a separate tab in the Weekly Report Archive section. Since site intrusive work has been completed and as approved by NYSDEC, future CAMP operations will only measure PM10 and the total volatile organic compound (TVOC) measurements were suspended on June 3, 2012.

For the week of June 11, 2012 through June 15, 2012, the WM contractor will continue conducting general Site maintenance, decommissioning and demobilization of the of the air handling system (remaining two TIGG Units), construction equipment, supplies and materials associated with the on-site waste management operation. Further, the WM contractor is scheduled to continue the removal of the jet grouting working asphalt platforms. The asphalt platform materials will be recycled at a NGRID approved off-site hot mix asphalt plant (the WM’s facility). Six fixed base CAMP units will be in operation to measure PM10. Dust suppression activities will be conducted, as necessary. The contractor will perform general maintenance activities and housekeeping at the Site, as necessary.