ITHACA — An updated plan on how to clean up environmental contamination at Emerson Power Transmission on Ithaca's South Hill should be available for public comment next month.
Gregg Townsend, regional hazardous waste remediation engineer with the Department of Environmental Conservation, said the plan — an amendment to the Department's 1994 Record of Decision — is “the next big step in the process” and will include alternative strategies to remove or neutralize the extensive contamination in and around the factory.
The factory's previous owner, BorgWarner, used degreasers containing trichloroethylene, or TCE, until the late 1970s. Under BorgWarner, TCE spilled into the factory's fire water reservoir and was dumped directly into municipal sewers, according to the final alternatives analysis submitted by Emerson to the DEC in late September.
A likely carcinogen, TCE breaks down slowly in soil and groundwater and can migrate into indoor air through soil vapor intrusion.
The strategy Emerson has tried for the last 14 years, pumping and treating contaminated groundwater, has proven largely ineffective, according to reports by Emerson's consultants, which show continued high readings of TCE and other contaminants in soil, water, and vapor in and near the factory.
According to the final report, Emerson will have to conduct tests to evaluate other potential technologies to eliminate contamination, such as “in-situ bioremediation,” a process by which microbes are added to contamination to help it break down, and “in-situ chemical oxidation,” a process by which oxidizing chemicals such as hydrogen peroxide or potassium permanganate are added to contamination to turn it to mineral.
Potassium permanganate has been used successfully on the same type of contamination up the street at the South Hill Business Campus, the site of the former Axiohm factory, Townsend said, and it or another oxidizer could work at Emerson, too.
“It's the same type of geology, the fractured bedrock. It's the same types of contaminants, the chlorinated solvents, so I think that that is one technology they are going to evaluate,” he said.
In the end, Emerson may need to try a variety of approaches at various locations, depending on factors such as geology, accessibility and cost, he said.
“Some technologies may be more effective than others, and may result in a quicker cleanup, but the cost associated with that may be more, too, so they really have to take all of those factors into account when they make a recommendation to us,” Townsend said. “They would like to have the treatment complete as quickly as possible — within a couple years would be great.”
The DEC would likely issue its amended Record of Decision in December, Townsend said. Emerson would conduct pilot tests of various technologies and construction on a new cleanup system would begin next summer, he said.
