As a precaution, recreation on the Mill Creek and Ohio River downstream of Cincinnati should be avoided

MSD’s Mill Creek Wastewater Treatment plant in Lower Price Hill lost all electrical power the morning of March 5, 2023 after a high voltage substation transformer failure. As a result, untreated or partially treated wastewater is being discharged to the Mill Creek and Ohio River.

The discharges are downstream of the Ohio River intake for Greater Cincinnati Water Works. Thus, there is no impact to local drinking water. However, recreation on the lower Mill Creek and the Ohio River downstream of Cincinnati should be avoided as a precaution.

MSD is working to restore power as quickly as possible. The Ohio EPA and other agencies have been notified, and MSD’s operations are being modified to limit discharges. MSD is also installing several megawatts of portable backup generators to provide as much wastewater treatment as possible, as quickly as possible.

The incident occurred around 7:30 a.m. after a brief power outage and a subsequent power surge caused a high voltage substation transformer to fail catastrophically. No one was injured, but initial inspections indicate that some large and specialized high-voltage equipment sustained irreparable damage.