
Weekly Update Ending: Week October 28, 2011
National Grid Report on MGP site remediation
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![]() Tent repairs continue |
National Grid’s contractor and Project Team continued to plan for the composite 120-foot deep dense non-aqueous phase liquid (DNAPL) Migration Barrier Wall (i.e., jet grouted barrier) installation. The contractor continued Phase 3 remediation construction activities and general maintenance of the Site. The contractor also completed the assembly and commenced the start-up and testing of the jet grouting system. The contractor continued to conduct Site preparations including the construction of the Waste Management Facility (WMF) and fabric repairs to the temporary fabric enclosure (i.e., tent). The WMF, which manages wastes (e.g., soils, cement mix and water) that are generated from jet grouting activities, will be operated inside the tent with an active Vapor Management System (VMS). All jet grouting wastes will be managed in accordance with NYSDEC approved procedures. The jet grouting contractor (JGC) and waste management and emergency response (WM/ER) contractors prepared pre-mobilization submittals and scheduled activities for the project. Attached are photographs of the site preparation activities.
![]() Grout plant nearing completion |
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 October 24, 2011 through October 30, 2011, six fixed base CAMP units were in operation and measured total volatile organic compounds (TVOC) and particulates (PM10). Fifteen-minute averages for both TVOC and PM10 data remained in the Operational Condition. There were no elevated readings for TVOC or PM10 for this monitoring period. The Weekly Reportthat summarizes the CAMP data can be found as a separate tab in the Weekly Report Archive section.
For the week of October 31, 2011 through November 4, 2011, Phase 3 remediation construction activities are scheduled to continue at the Site. The contractor is scheduled to complete the start-up and testing of the Jet Grout Plant system and commence the Pre-Production Program. The contractor is scheduled to complete the site preparations including the WMF, and fabric repairs to the temporary fabric enclosure (i.e., tent), and setup of the VMS. In addition, the contractor will conduct general maintenance activities and housekeeping at the Site, as necessary. Dust suppression activities will be conducted, as necessary.