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 acted 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 has completed nine rounds of permanganate injection from September 2005 to September 2007.  A total of 8,684 gallons of sodium permanganate solution has been injected into the treatment area to date.  Ongoing ground water monitoring indicates that the permanganate reagent has been delivered throughout much of the treatment cell.

Olympia is currently in the process of developing a scope of work to address two outstanding issues: (1) TCE contamination remaining in lower permeability soils within the treatment cell, and (2) a TCE plume in the downgradient area between the cell and the Aberjona River.  To collect data necessary for this scope of work, Olympia conducted a gauging and survey event on March 7, 2008 and a comprehensive permanganate distribution monitoring event on March 14, 2008.  The draft scope of work was submitted on March 14, 2008.  Based on this draft submittal, EPA provided comments back to Olympia on April 8, 2008.

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's final scope of work (for the lower permeability soils in the treatment cell and the plume between the cell and the Aberjona River) is due on April 30, 2008.  Field activities described in this scope of work will be conducted during this construction season.