Materials being delivered

National Grid’s contractor and Project Team continued to construct the composite 120-foot deep dense non-aqueous phase liquid (DNAPL) Migration Barrier Wall (i.e., jet grouted barrier). The contractor continued the Production Jet Grouted Column Barrier Wall Installation Program. The contractor continued the management of jet grouting derived wastes within the Waste Management Facility (WMF). The WMF, which manages wastes (e.g., soils, cement mix and water) that are generated from jet grouting activities, is operated inside the tent with an active Vapor Management System (VMS). Jet grouting wastes were managed in accordance with NYSDEC approved procedures and wastes were disposed of off-site at a licensed and permitted disposal facility. General maintenance and security activities also continued at the Site. Attached are progress site photographs of the daily set-up of the waste tub and the delivery of the grout mix materials (e.g., slag and cement).

Waste Tub being set up

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 January 30 2012 through February 5, 2012, 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. On Friday, February 3, 2012 at approximately 15:19 Hours (3:19 PM), an elevated PM10 reading was observed at FAM5 and was attributed to an unknown off-site source and the site remained in the Operational Condition. 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 February 6, 2012 through February 10, 2012, the contractor is scheduled to continue the Jet Grouting Production Program and conduct the load-out of the jet grouting derived wastes. Dust suppression activities will be conducted, as necessary. The contractor will perform general maintenance activities and housekeeping at the Site, as necessary.