CHILLICOTHE, Ohio — Six new groundwater monitoring wells are planned around the former WearEver facility in Chillicothe as state regulators and Howmet Aerospace continue evaluating what could happen to the site’s contaminated groundwater plume following major changes in groundwater pumping at the neighboring paper mill.
A Sept. 11 Monitoring Well Installation Work Plan prepared for Howmet Aerospace by Key Environmental Inc. says Ohio EPA and Howmet have agreed on the locations of six additional monitoring wells.
The expansion comes after more than a year of heightened scrutiny surrounding the contaminated groundwater beneath and beyond the former WearEver property.
The six wells will not remove or treat the contamination. Their purpose is monitoring — giving regulators additional points from which to measure groundwater conditions and track whether the plume changes direction or expands.
The distinction is important.
The groundwater remedy established for the site calls for controlling access to contaminated groundwater, monitoring the plume and ultimately achieving federal Maximum Contaminant Levels for certain volatile organic compounds. Ohio EPA’s longstanding remedy also contains specific contingencies for changes in operation of industrial wells along the Scioto River that could cause the contaminated plume to change in size or direction.
Four shallow wells, two deeper wells
According to the Sept. 11 work plan, four of the new wells — H-S, OS-2-S, OS-4-S and OS-5-S — will monitor the shallow groundwater zone and extend to approximately 32 feet below ground.
Two additional wells, OS-4-I and OS-5-I, will reach the intermediate groundwater zone at approximately 60 feet.
The shallow and intermediate zones consist primarily of sand and gravel and are hydraulically connected, according to the plan, although the shallow zone contains more fine material.
Howmet is working to obtain access agreements from neighboring property owners before drilling begins.
Once access is secured, Key Environmental estimates drilling, installation, development and surveying of all six wells can be completed within approximately two weeks.
Results and construction details are expected to be incorporated into quarterly reports submitted to Ohio EPA.
Why the additional monitoring matters
The new wells are the latest development in a groundwater problem that has existed for decades.
Historical manufacturing at the former WearEver facility contaminated groundwater with volatile organic compounds.
For years, groundwater pumping at the neighboring paper mill influenced groundwater beneath the area.
That became particularly important when the mill’s future changed.
In a July 2025 letter, Ohio EPA raised concerns about the anticipated cessation of pumping from the paper mill’s Collector Wells 17 and 18. The state’s existing remedy specifically anticipated circumstances in which changes to industrial wells along the Scioto River could cause the contaminated groundwater plume to change in size or direction.
Historical monitoring documented groundwater flowing northeast, east and southeast at different times. Howmet’s consultant reported that changes in the paper mill’s pumping had previously altered groundwater flow for extended periods, including southeastward shifts between 2008 and 2013 and again between 2020 and 2021.
Earlier proposal included additional sentinel locations
Documents from August 2025 also provide important context for how the current monitoring network developed.
At that time, Howmet agreed to install wells at two locations proposed by Ohio EPA beyond the southeastern property boundary, identified as OS-4 and OS-5.
But Howmet pushed back on two other proposed monitoring locations.
According to the company’s Aug. 1, 2025 response to Ohio EPA, Howmet said there was not a “clear benefit” to installing proposed wells OS-6 and OS-7 because those locations were east-northeast of the facility and would not be downgradient if groundwater returned to its natural southeastward flow direction.
Howmet instead proposed using statistical trend analysis at perimeter wells to identify possible plume expansion or migration and said increasing contaminant trends could be used to determine whether additional wells or remediation were necessary.
Contamination remains
The expanded monitoring comes as recent sampling continues to document significant groundwater contamination at the site.
A fourth-quarter 2025 report showed TCE at 390 micrograms per liter in shallow monitoring well MW-D-S — 78 times the federal drinking-water Maximum Contaminant Level of 5 micrograms per liter. Other volatile organic compounds have also continued to be detected in the groundwater.
The paper mill’s shutdown brought renewed attention to that contamination because its high-capacity wells had influenced groundwater movement for decades.
That uncertainty is precisely what the expanded monitoring network is intended to address.
Once groundwater conditions without the historical influence of the paper mill’s pumping are characterized, Howmet has said an updated conceptual model will be developed and a revised remedial approach will be submitted to Ohio EPA for evaluation and approval.
For residents living around one of Chillicothe’s longest-running environmental contamination sites, the six new wells should provide regulators with more information about where the plume is moving.
But they are monitoring wells — not a cleanup system.
And more than three decades after contamination beneath the former WearEver property became an environmental concern, the central question remains unresolved:
WHEN WILL THEY CLEANUP WEAR-EVER!
