 Interior view of tent under construction in Position 1 |
National Grid’s Remediation Contractor continued with site remediation activities, which included the delivery of construction materials, imported backfill material (clean fill), construction equipment and supplies. Installation of the on-site Waterloo Barrier Wall continued to progress from east to west across the northern part of the site. Record of construction surveys and construction stake-out surveys continued as site remediation activities progress. Assembly and construction of the Tent Position #1 (southeast corner of the site) continued and included the erection of the structural members and fabric panels plus the installation of the vapor management system (VMS). Noise and vibration monitoring activities were conducted during the sheet piling operations of the on-site barrier wall (Waterloo DNAPL Migration Barrier Wall).
Personnel and equipment decontamination pads were utilized throughout site operations. Further delineation of work zones (i.e., exclusion, decontamination, and support) continued, as required. Maintenance of the on-site gravel access roads, parking areas and material staging areas, the imported backfill material (i.e., clean fill) stockpile covers, and repair of the perimeter privacy screen continued. Imported clean fill materials continued to be staged in the central part of the site and utilized as backfill material for the construction of a stabilized working platform for the Waterloo DNAPL Migration Barrier Wall sheet piling rig. Maintenance of engineering controls and soil erosion and sediment control (SESC) measures continued. Odor and dust suppression activities were conducted, as necessary. National Grid’s consulting engineer continued to monitor the site activities with the fixed base community air monitoring program (CAMP) equipment.
CAMP data is reviewed and compared to specific NYSDEC/NYSDOH approved criteria, known as “Action Limits.” As a result of this evaluation process, site conditions are categorized into two categories, “Operational Condition” and “Action Condition.” The “Operational Condition” is applicable when the data is below the “Action Limits”, and means that normal operations can continue. The “Action Condition” occurs when one or more of the fifteen minute average measurements for Dust (PM10), Total Volatile Organic Compounds (TVOC), Naphthalene or Odor Intensity are greater than the background or upwind measurement by the specified “Action Limits.” Reaching an Action Level requires corrective action or stopping work until the condition is addressed or abates. During the period from April 20, 2009 through April 26, 2009, sixed base CAMP units and one portable CAMP unit were in-use and measured TVOC and PM10. Fifteen-minute averages for TVOC and PM10 data remained in the Operational Condition. Weekly Reports of the CAMP data can be found as a separate tab in the Weekly Report Archive section.
For the week of April 27, 2009 through May 1, 2009, installation of the on-site Waterloo Barrier Wall will continue from east to west across the northern part of the site. Final assembly of the temporary fabric enclosure at Tent Position #1 including the erection of the structural members, fabric panels, and the installation of the VMS is scheduled for completion. After the temporary fabric enclosure is erected and the VMS determined to be operational, shallow excavation activities will commence inside at Tent Position # 1. Upgrade and maintenance of the on-site gravel access roads, truck lining and tarping stations, and personal and equipment decontamination pads will continue. National Grid’s consulting engineer will continue to monitor the site activities with noise and vibration monitoring equipment. Odor and dust suppression activities will be conducted as necessary. National Grid’s consulting engineer will continue to monitor the site activities with CAMP equipment.
On April 22, 2009 NYSDEC approved Field Change Requests FCR-01 through FCR-03; FCR-01 through FCR-03 have also been posted to the website.