CHILLICOTHE, Ohio — US Paper Mill LLC, the company operating Chillicothe’s paper plant, reported its own wastewater discharge to Ohio EPA as over the plant’s pH limit on nine separate days in October 2025 — and told the agency the readings were the fault of a malfunctioning monitoring probe, not the discharge itself.
The disclosure is in a Non-compliance Notification the company filed with Ohio EPA’s Division of Surface Water, dated Nov. 24, 2025, and available in the agency’s eDocs public records portal. J News Network reviewed the filing as part of The Fallout Files, its ongoing examination of the plant’s environmental record.
Under the plant’s Ohio NPDES permit, No. 0IA00002*LD, the daily maximum pH of the plant’s final effluent is 9.0 standard units. The company’s continuous pH monitor recorded daily maximums above that cap on Oct. 5, 7, 12, 20, 21, 23, 25, 26 and 27, 2025, with the highest reading — 9.8 — recorded on Oct. 27, according to the filing.
The company, however, told Ohio EPA the over-limit readings did not reflect the actual discharge. In the filing, US Paper Mill states that its daily grab samples — physical samples collected and tested separately from the continuous monitor — measured between 8.1 and 8.3 on each of those same days, below the 9.0 limit.
“Continuous pH monitoring indicated a maximum daily pH above 9.0; however, this was due to a pH instrument issue,” the company wrote in the notification.
“Maximum readings were short in duration and daily grab samples were below 9.0, which indicated an pH instrument issue, rather than a true high level pH,” the filing states.
The company reported the total period of exceedance as 0.20 hours on Oct. 5, 2025. It said its electrical and instrumentation technicians cleaned and calibrated the pH probe on Oct. 31, 2025, and that readings since the calibration have run between 8.3 and 8.5 — consistent, the company said, with the grab sample data. The filing lists Kimberly Lute as the company’s primary contact on the report.
The notification is a self-report, the form facilities use to disclose permit non-compliance to Ohio EPA under Part III, Section 12 of an NPDES permit. On the form, the company answered “No” to whether it was also reporting non-compliance with any other permit condition. The filing does not state whether Ohio EPA accepted the company’s instrument-error explanation or took any action in response, and no agency response appears in the document.
pH measures how acidic or alkaline water is, on a scale of 0 to 14. Discharge limits in an NPDES permit are the enforceable conditions under which a facility may release treated wastewater, and permit holders are required to report exceedances to Ohio EPA whether or not they believe a monitoring error caused the reading.
The Chillicothe plant, the city’s longtime paper mill, operates under US Paper Mill LLC following the site’s earlier life as the Pixelle and Glatfelter mill. Its discharge record — and the record of the neighboring former WearEver aluminum site — has been the subject of continuing Fallout Files reporting.
This story is based on US Paper Mill LLC’s Non-compliance Notification filed with Ohio EPA’s Division of Surface Water (NPDES permit 0IA00002*LD), dated Nov. 24, 2025, obtained from Ohio EPA’s eDocs portal, document ID 4304747. J News Network will update this story with any response from Ohio EPA or US Paper Mill LLC.
