United States Environmental Protection Agency
Region I
POLLUTION REPORT

Subject: 

The Wells G & H Superfund Site covers approximately 330 acres in Woburn, Middlesex County, Massachusetts.  The Site includes the aquifer and land area located within the zone of contribution to the City of Woburn’s two municipal drinking water wells known as Wells G & H.  The Olympia Property is one of the five primary source areas of contamination within the Federal Superfund Site.

At a former drum disposal area at the Site, PCB-contaminated surface soils posed a direct contact threat and TCE-contaminated subsurface soils are acting as a continuing source of ground water contamination.  See previous polreps for additional background information.

The Olympia Nominee Trust (Olympia) has been identified as a potentially responsible party (PRP) as the owner of the site.  Olympia is performing the removal action under an Administrative Order on Consent (AOC) issued by EPA.  In order to address TCE contamination in subsurface soils at the Site, Olympia has installed and is now operating an in situ permanganate injection treatment system.  See previous polreps for prior activities conducted by Olympia.

Olympia completed the initial 8 rounds of permanganate injection in December 2005.  A total of 8,464 gallons of sodium permanganate solution has been injected to date.  Monitoring data collected since that time indicates that the permanganate reagent has been effectively delivered throughout much of the treatment cell.  However, several areas within the cell may need additional reagent.  In addition, two areas outside and adjacent to the cell require additional assessment and possible treatment.  

Olympia conducted a comprehensive ground water monitoring event from April 24-26, 2007.

Planned removal activities include continued monitoring to ensure compliance with cleanup standards established in the Record of Decision (ROD).  Future injections will be conducted on an as-needed basis to achieve the cleanup standards.

Olympia plans to remobilize on May 14, 2007 to address areas which may need additional reagent.  Olympia plans to install additional soil borings/monitoring wells to assess these areas and install additional injections wells.