BOSTON, Mass. — Cleanups completed at two superfund sites in Maine have reduced the chances of the public being exposed to contaminants in groundwater, according to reports issued recently by the Environmental Protection Agency.
Superfund is the name of the federal environmental program established to address abandoned hazardous waste sites. It is also the name of the fund established by law that allows the EPA to clean up such sites. The law allows the EPA to compel responsible parties to perform cleanups or reimburse the government.
The EPA conducts evaluations every five years of previously completed cleanup and remediation sites to determine whether the implemented remedies are protecting human health and the environment. The two Maine sites — the McKin Co. in Gray and Hows Corner in Plymouth — were among 22 listed in New England as having been recently reviewed by the EPA, according to a Jan. 30 news release.
The McKin Co. site’s fifth review was conducted in August 2013, and states cleanup efforts are working to protect residents in Gray, according to the 41-page EPA report.
Approximately 320 schools, government agencies, hospitals and private businesses in Maine that shipped waste oil and spent solvents to the landfill in Gray have spent in excess of $18 million to clean up contamination over the years.
The review of the West-Hows Corner site in Plymouth, its second five-year review, states a groundwater containment system was installed in 2011 and long-term groundwater monitoring already in place is needed to determine its effectiveness, the 116-page EPA report states. Early indications are that volatile organic compound contaminants are decreasing.
Some 250 potentially responsible parties allegedly disposed of thousands of gallons of used motor oil, degreasers and solvents at the Hows Corner site, and have been paying for the cleanup for the last 20 years.
A consent decree issued in U.S. District Court in Bangor in 2010 settled the federal lawsuit against the responsible parties for $14 million. That included $11.2 million for the groundwater hydraulic containment system to capture and filter contaminated groundwater at the site.
Residents in the area of both cleanup sites in Maine were connected or have been offered the ability to connect to public water systems, according to the EPA.
The 7-acre McKin Co. site is located on the west side of Mayall Road in Gray. It operated between 1965 and 1978 as a storage and dumping ground for waste oil and industrial process waste. The former waste collection, transfer and disposal facility at the time operated in a former sand and gravel pit.
The plant handled and disposed of millions of gallons of solvents, oils, and other chemicals, including waste recovered in 1972 when a Norwegian tanker ran aground on a ledge in Hussey Sound, spilling 100,000 gallons of industrial fuel.
Odors in well water and discoloration of laundry were reported as early as 1973, and in 1977, the EPA confirmed that contaminated groundwater had reached many of the local private wells.
A total of 16 private wells were capped and public water was extended to the area the following year. The soil was remediated, groundwater was pumped out until 2001, and a spring along the Royal River was capped to stop and contain any harmful effects of the contaminants.
There is no known current exposure of Gray residents to the groundwater, since all residents are connected to the public water supply, and the town has passed rules banning the use of groundwater from the area, the EPA’s five-year report states.
“Regression analysis of groundwater data through Spring 2013 indicates the contaminant concentrations are continuing to decrease and drinking water standards may be attained more quickly in some locations than was originally calculated during the mediation process,” the report states.
“Based on the updated regression analysis through the 2012 monitoring data, the drinking water standards may be attained in about 2035,” the report later states.
The Hows Corner site, also known as the West site, was a waste oil facility owned and operated by George West from 1965 to 1980 in affiliation with the Portland/Bangor Waste Oil Co.
The business’s aboveground storage tanks were removed in 1980 after the Portland/Bangor Waste Oil Co. ceased operations at the Plymouth site. A chain link fence was partially installed by the Maine Department of Environmental Protection in 1988 and completed by the EPA in 1990.
From 1990 to 1991, EPA removed approximately 850 tons of contaminated soil from the center of the site and disposed of it at a federally approved toxic waste facility. An alternate water line was installed in 1993-’94 for residents with or determined to be at risk of having contaminated groundwater, the EPA report states.
Seven of these 14 properties are connected to public water but are not protected by a recorded covenant, the report states.
“While no one is currently being exposed to contaminated groundwater, continued use of existing private wells or the installation of new private wells could result in people being exposed to unsafe levels of contamination at some time in the future,” the EPA report states.
Plymouth leaders passed a 2003 zoning ordinance that prevents the use of groundwater for the area around the Hows Corner site.
A groundwater containment system was installed in 2011. It includes a bedrock well that pumps the contaminated groundwater up through an aboveground treatment system; then the clean water is pumped back into the bedrock, the EPA report states.
“Based on a review of the long-term monitoring groundwater data from 2012, the extent of the VOC [volatile organic compounds] groundwater plume in both shallow and deep bedrock groundwater has been reduced,” the report states.
Next on the list of five-year superfund reviews for Maine is the Saco Tannery waste pits, which will start this year, Emily Zimmerman, EPA spokeswoman, said Tuesday.
“In addition to a careful evaluation of technical work at the sites, during the five-year review process EPA also provides the public with an opportunity to evaluate preliminary findings and to provide input on potential follow up activity that may be required following the review process,” she said about the evaluation process.
Messages left with Maine environmental groups seeking comment on the reports were not immediately returned Tuesday.
Watch Bangordailynews.com for updates.