CHILLICOTHE — More than 27 years after Ohio regulators ordered cleanup measures at Chillicothe’s former WearEver manufacturing plant, new groundwater testing shows industrial chemicals remain beneath the property and have migrated beyond its boundaries, with some results far exceeding federal drinking-water standards. Two reports prepared for Howmet Aerospace and dated Oct. 10, 2026, document continuing contamination involving trichloroethylene, vinyl chloride and other chlorinated solvents.
Testing conducted June 23 found vinyl chloride at 230 micrograms per liter in one on-site monitoring well — about 115 times the federal drinking-water standard of 2 — and trichloroethylene at 260 micrograms per liter, 52 times its standard of 5. Another compound, cis-1,2-dichloroethylene, measured 2,300 micrograms per liter, about 33 times its standard, and a second on-site well recorded trichloroethylene at 44 times the federal limit.
The contamination is not confined to the former factory property. An off-site monitoring well documented cis-1,2-dichloroethylene at 300 micrograms per liter, along with trichloroethylene and vinyl chloride, all above their respective federal standards. One off-site well east of the property showed no site-related chemicals in the June sampling, but the reports describe a plume that has persisted under state oversight since 1999 and remains one of the most closely watched sites in Ohio.
Much of the containment strategy depends on the neighboring former paper mill. For decades, high-capacity industrial wells at the mill have pulled groundwater toward the east and northeast, helping control the direction of the plume. The June report says collector well 17, about 2,000 feet from the site, was not operating during the monitoring event, and it warns that if industrial pumping decreases substantially or stops, groundwater beneath the former plant would likely move east-southeast, generally toward the Scioto River.
That warning matters because the former mill property is undergoing major ownership and operational changes, with new industrial and digital infrastructure uses proposed for portions of its water and wastewater systems. Parties involved in the transition have said the wells will remain operational, but the reports caution that new uses are unlikely to require the same volume of pumping that paper manufacturing historically did, leaving the longer-term pumping plans of U.S. Paper Mill uncertain.
At the same time, a planned expansion of the monitoring network remains delayed. Ohio EPA raised concerns in July 2025 about reduced pumping and requested additional wells, and Howmet negotiated a revised plan — but an October progress report says access agreements sent to nearby property owners in October 2025 had not been returned signed, so the new wells have not been installed. Two existing wells also could not be sampled in June because dense vegetation, including poison ivy, created safety concerns; the area has since been cleared.
The filings also note that a vapor-protection system in an unoccupied warehouse area was repaired after a drive unit failed, and that 14 additional samples collected Aug. 19 and 20 await a separate third-quarter report. Howmet says enhanced quarterly monitoring begun in 2025 will continue until conditions are better understood. For Chillicothe residents, the next filings should show whether levels are changing — and whether the monitoring and pumping the cleanup depends on will stay in place.