Lawton cited for high ammonia levels in wastewater discharge

The City of Lawton has a new Notice of Violation against its wastewater treatment plant.

City officials confirmed Tuesday they had received a Notice of Violation from the Oklahoma Department of Environmental Quality (ODEQ) citing “discharge without a permit” as the primary issue, with data specifying high ammonia concentrations.

The notice references an incident on July 7, when a Walters resident reported eight fish found dead in East Cache Creek near Sultan Park, located 25 miles south of the wastewater plant. The notice includes plant data from June 22 to July 8, indicating effluent (discharged water) ammonia concentrations ranged from 14.3 mg/L to 21.5 mg/L, exceeding the ammonia toxicity threshold for fish.

City officials said they have 15 days to respond to the notice and will provide ODEQ with a detailed written plan outlining the city’s commitment and steps to correct the violation and ensure compliance with environmental regulations.

Despite the recent Notice of Violation, city officials say they continue to make significant progress in improving the wastewater treatment plant.

Staff has completed reseeding the activated sludge basins and biological activity is thriving on its own, plant officials said of the treatment process that is essential for breaking down solids and ensuring effective nitrification (breaking down ammonia), settling and disinfection in downstream processes. Continuous maintenance also is being performed on upstream processes, including grit removal and hauling, primary clarifier repairs, and replacing the trickling filter tower rotating mechanisms, all crucial for sustaining the activated sludge’s food source.

City officials said further enhancements are underway, including installation of a new influent pump station with upgraded pumps, coarse and fine screens, vortex grit removal, to ensure complete solids removal. Aeration blowers also will be replaced with redundancy to ensure proper aeration of the activated sludge process.