CTS site's soil and groundwater contaminated with trichloroethene and other VOCs
The U.S. Environmental Protection Agency (EPA) has selected an interim cleanup plan to address contamination beneath the former plant at the CTS of Asheville Inc. Superfund site. The North Carolina Department of Environmental Quality concurred with EPA’s decision.
Historical use of solvents in the manufacturing of electronic components at the CTS Site contaminated the soil and groundwater with trichloroethene (TCE) and other volatile organic compounds (VOCs). TCE has been linked to various illnesses in humans, ranging from effects on the central nervous system, liver, kidneys and immune and endocrine systems to certain types of cancer. The extent and nature of potential health effects depend on many factors, including the contaminant levels and the length of exposure to the pollution.
EPA held a public meeting on Oct. 13, 2015; took public comment for 60 days; and considered public input before finalizing the plan. The majority of the comments received encouraged EPA to expand the 1-acre treatment area originally proposed to include approximately two additional acres to the north. As a result, CTS submitted an evaluation of treatment options for this expanded area for EPA’s consideration.
Under the final cleanup plan, 3.1 acres will be treated to address non-aqueous phase liquid (NAPL) and TCE in the groundwater beneath the former CTS plant site, located at 235 Mills Gap Road. Approximately 208,250 cu yd of material in the saturated zone between the observed water table and top of competent bedrock will be cleaned up using a combination of electrical resistance heating (ERH) and in-situ chemical oxidation (ISCO).
ERH is a technology that heats the ground in order to vaporize contaminants. Contaminated vapor then is recovered using vents and treated above ground before being discharged to the air. ISCO involves the injection of chemicals into the ground. The chemicals oxidize and break down the contaminants into harmless byproducts like carbon dioxide and water.
The major components of the selected interim remedy include:
- ERH to treat the mixed NAPL and TCE plume in an approximately 1.2-acre area. ERH will address about 47,250 cu yd of saturated material contaminated by NAPL/TCE.
- ISCO to treat the TCE-only contamination in an area to the north of the area being treated by ERH. The volume of this 1.9-acre treatment area is approximately 161,000 cu yd.
- Monitoring will be conducted while the remedy is implemented to ensure adequate protection of onsite workers and the surrounding community.
The technologies are expected to reduce TCE concentrations in the treated areas by 95%, and performance data will be collected to demonstrate the effectiveness in meeting this objective. Groundwater also will be monitored to evaluate the anticipated decreasing concentration of TCE in the deeper bedrock aquifer over time.
The total estimated cost of the interim remedy is $9,035,000. The Superfund program operates on the principle that polluters should pay for cleanups. EPA expects to work with the potentially responsible parties to reach a legal agreement to implement the work specified.
EPA anticipates that design and implementation of the interim remedy will begin later in 2016. It will continue to keep the community updated throughout this process. The interim remedy will be followed by a final site-wide cleanup decision that is not expected for several years.