EPA sets cleanup plan for Ohio Superfund chemical site

Chicago, IL— U.S. Environmental Protection Agency Region 5 has reached a decision on a cleanup plan for the Nease Chemical Superfund site in Columbiana County, Ohio.

The 44-acre site is northwest of Salem on the Columbiana-Mahoning county line. Between 1961 and 1973, Nease Chemical produced household cleaning products, fire retardants and pesticides at the site.

EPA is most concerned about mirex, which was used in pesticide production and disposed of in soil and unlined ponds at the property. EPA is also concerned about ground water contamination beneath the site. The site was placed on the Superfund National Priorities List in 1983.

The $19 million plan includes a mix of innovative pond-chemical removal methods, soil capping and ground water treatment methods. EPA, working in consultation with Ohio EPA, evaluated five cleanup options addressing four distinct areas of the site and held a 30-day public comment period on its proposed option before selecting the cleanup plan.

The plan calls for ponds 1 and 2 to be treated with a combination of methods in which a device with rotating metal blades is sunk beneath the surface of the ponds to churn up chemicals and bring them to the surface for capture, treatment and disposal before they can evaporate in the air.

When most of the contamination has been removed, the device will be used to mix a cement-like substance into the ground to prevent any remaining contamination from spreading.

Ponds 1, 2 and 7 and exclusion areas A and B will be covered with thick plastic sheets and a layer of clean soil to prevent rain from soaking through and spreading remaining contaminants. Other areas, such as ponds 3 and 4, will be covered with clean soil only to prevent contact with contaminants.

Shallow ground water on the eastern side of the site will be collected in a trench, pumped above the ground and treated to remove contamination. Deep ground water and the southern area will be treated by injecting a substance known as “nanoscale zero-valent iron.” This cutting-edge process uses microscopic particles of specially treated iron to clean the ground water chemically.