EPA Reports 98% Drop in Toxic Vapors at CTS of Asheville Superfund Site

Toxic vapor levels at the CTS of Asheville Superfund Site have fallen by 98%, according to the U.S. Environmental Protection Agency. The figure, released by the agency, marks one of the sharpest documented reductions in vapor intrusion at a Superfund cleanup in the region.

The announcement concerns the contaminated former CTS Corporation plant site in Asheville, North Carolina, where chlorinated solvents in soil and groundwater have driven years of remediation work and property disputes. Vapor intrusion — the migration of chemical vapors from subsurface contamination into overlying buildings — has been the central exposure pathway regulators have worked to shut down.

What does the 98% reduction mean?

The EPA statement quantifies the cumulative effect of the site's vapor mitigation and source-control measures. A reduction of this scale indicates that the systems installed to capture and vent subsurface vapors, and the treatment of the contamination driving them, are performing as designed.

For a Superfund site, vapor data of this kind serves a specific regulatory function. It feeds into the five-year review process, informs decisions on whether land use restrictions can be adjusted, and determines when mitigation systems can be scaled back or retired. EPA has not, in this release, tied the figure to a specific deadline for delisting or for lifting institutional controls on the property.

Which material stream drove the contamination?

The CTS of Asheville site is a legacy industrial facility. The plant, which manufactured electronic components, left behind chlorinated solvent contamination — the classic trichloroethylene-family groundwater plume profile familiar from decades of American electronics manufacturing. Those solvents persist in subsurface soil and groundwater, partition into vapor, and migrate through soil gas into buildings, which is why vapor intrusion dominates the risk picture at such sites.

This places Asheville in a wide cohort of former electronics and metal-finishing sites where the remediation currency is not tonnage of recycled material but mass of solvent extracted, destroyed or isolated — measured over decades rather than fiscal quarters.

What happens next?

The 98% figure sets a benchmark, not an endpoint. Superfund cleanups at solvent sites typically require sustained monitoring to confirm that vapor reductions hold once active systems are throttled back. Regulators will track whether the number survives long-term verification, and EPA's next formal review of the site will determine whether the remedy is judged protective for unrestricted future use.

For the surrounding community, the decisive milestone remains the agency's finding of long-term protectiveness — the regulatory step that converts a favorable vapor reading into a land-use decision. Until EPA issues that finding, the site stays on the National Priorities List with its restrictions intact.

The EPA's stated 98% reduction is the number to watch. Its confirmation in subsequent monitoring rounds is what decides what happens next.