Site nearing start of jet grout process

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 completed the start-up and testing of the Jet Grout Plant system and commenced the Pre-Production Program. The contractor completed the site preparation activities which included the Waste Management Facility (WMF), and fabric repairs to the temporary fabric enclosure (i.e., tent), and setup of the Vapor Management System (VMS). 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 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.

Jet Grout Rig

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 31, 2011 through November 6, 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 Report that summarizes the CAMP data can be found as a separate tab in the Weekly Report Archive section.

For the week of November 7, 2011 through November 11, 2011, Phase 3 remediation construction activities are scheduled to continue at the Site. The contractor is scheduled to continue the Pre-Production Program. In addition, the contractor will conduct general maintenance activities and housekeeping at the Site, as necessary. Dust suppression activities will be conducted, as necessary.

                          

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.