Following are the steps most often required by the New York State Department of Environmental Conservation in the investigation and remediation of a former MGP site.
Remedial Investigation/Feasibility Study
Interim Remedial Measures
Record of Decision (or Decision Document)
Design and Construction
The Williamsburg former Manufactured Gas Plant site project is now in the Remedial Investigation phase. The field work for the Remedial Investigation phase will begin in Spring 2009 with the implementation of a sampling program throughout the site. National Grid has reached Access Agreements with owners of the privately owned properties to conduct sampling activities.
Remedial Investigation Activities Summary:
The NYSDEC determined that a Remedial Investigation of the site was required to determine the full nature and extent of contamination at this site.
The objectives of the Remedial Investigation are to complete the delineation of the horizontal and vertical extent of MGP impacts, determine the surface and subsurface characteristics of the site, identify sources of contamination, and identify migration pathways and potential human and ecological receptors at the site and in surrounding off-site areas. The field work will include sediment sampling, surface soil sampling, soil borings for subsurface soil sampling, installation of monitoring wells, groundwater sampling, aquifer testing, and collection of sub-slab soil vapor and indoor air samples.
The field work will be completed during normal business hours, and is not expected to disrupt any activities on neighboring properties. Field work will be supervised by representatives of the NYSDEC and, as necessary, the New York State Department of Health. A Community Air Monitoring Plan will be in effect to detect any airborne contaminants that could be released during the field activities, and to require prompt protective measures if they are detected. All samples will be sent to independent NYSDOH-accredited (ELAP) laboratories for analysis.
Remedial Investigation Report:
At the completion of the field work, a Remedial Investigation Report will be produced, which will include an Executive Summary, a description of the field activities, analytical results compared to NYSDEC guidance and standards, geological findings, Qualitative Human Health Exposure and Fish and Wildlife Impact Assessments. Appendices will include all of the pertinent data. Once the report is approved by NYSDEC and NYSDOH, the entire report and a summary Fact Sheet will be made available to the public.
All of this information and analyses will be used to ensure that National Grid and the NYSDEC have a full understanding of the nature and extent of the impacts to the environment of the former MGP operations. This information, in turn, will be used in the development of a Feasibility Study, which is an evaluation of technologies and activities to address the impacts as necessary.