State officials say Lawton not at fault for East Cache Creek fish kill

The Oklahoma Department of Environmental Quality (ODEQ) has officially cleared the City of Lawton of responsibility for the July 7 fish kill that occurred in East Cache Creek at Sultan Park in Walters.

The fish kill was initially linked to Lawton’s wastewater treatment plant in an anonymous report submitted to ODEQ on July 8. It prompted the agency to issue a Notice of Violation to Lawton for the discharge of partially-treated wastewater during upgrades to the treatment plant.

The city’s Aug. 13 response to the Notice of Violation provided evidence to show other environmental factors contributed to the fish kill. The plant’s discharge passed required toxicity tests in June, indicating it was not harmful to aquatic life at the time, city officials said.

Heavy rainfall occurred on July 4, causing East Cache Creek to flood and then recede, stranding larger fish. High temperatures over 100 degrees further stressed the fish by reducing oxygen levels in the water, ODEQ and city officials said.

Additionally, Lawton received reports that the prison east of the wastewater plant had an ongoing sanitary sewer overflow, which lasted for months and may have entered Nine Mile Creek, potentially contributing to further stress on the fish, city officials said.

The city took proactive steps to mitigate the situation by releasing water from Lake Ellsworth into Nine Mile Creek, increasing the flow of fresh water to East Cache Creek during July.

“We are pleased with ODEQ’s findings, which confirm that the fish kill was not the result of our wastewater treatment processes,” said City Manager John Ratliff. “I am also happy to report that the wastewater treatment plant has been in full compliance since July 26, 2024. We remain committed to continuing the rehabilitation of the WWTP and to ensuring full compliance with environmental standards moving forward.”

City officials said work also continues at the plant to further enhance the treatment process and ensure redundant operations are in place in the future.