The city of Tulsa is challenging an Arkansas agency’s modification of a Northwest Arkansas treatment plant’s permit that discharges into the watershed that supplies the Oklahoma city’s drinking water.
The city of Decatur’s wastewater plant receives waste from Centerton and a nearby Simmons Food plant and discharges into streams that feed Lakes Eucha and Spavinaw, from which Tulsa draws its water. Decatur entered into a consent order with the Arkansas Division of Environmental Quality last year over numerous violations of its federal Clean Water Act permit. Tulsa said the violations, which have continued since the order was signed, are reason enough to reject expanding the plant until Decatur complies with its original permit.
Tulsa has additional concerns: that the modified permit could result in higher levels of pollutants discharged into the watershed that supplies its drinking water.
The modified permit increases the plant capacity by just over 1.5 million gallons per day (MGD), to 5.36 MGD, reflecting the construction of additional capacity at the plant due to “rapidly increasing” waste flows. But Tulsa says modification shouldn’t be approved until plans for unaddressed “choke points” within the treatment plant are submitted and approved, or until a survey is completed to determine what waste pretreatment, if any, should be required.
“Decatur has no plans to increase pre-treatment or reduce the amount of wastewater which it takes from sources outside of Decatur,” Tulsa wrote in public comments on the permit in October. “The increase in flow via the permit modification should be denied until such time as Decatur can increase flow while also decreasing the total amount of phosphorus which Decatur discharges into the watershed.”
Decatur and Tulsa are parties to a 2003 federal court settlement that came after Tulsa sued Decatur and six poultry companies in 2001, alleging that discharges by the companies and the city’s wastewater plant contained phosphorus that polluted Lakes Eucha and Spavinaw, where Tulsa gets its drinking water.
Tulsa argued in its request for an administrative hearing with the Arkansas Pollution Control and Ecology Commission that the modified permit violates the 2003 settlement and that the city is “directly and negatively impacted by the issuance of [Decatur’s modified permit].” Tulsa wrote the permit is unable “to address Decatur’s long history of numerous violations of the Settlement Agreement between Tulsa and Decatur,” nor was it able to address violations under the current permit and “ADEQ’s own water quality standards.”
Administrative permit appeals are an uncommon event in recent years — this is the first filed with the commission since 2023.
A spokesperson with the city of Tulsa on Friday was unable to provide further information without speaking with Tulsa’s water utility board and the lawyers representing them in the challenge.
Tulsa’s 2001 lawsuit was separate from ongoing efforts by successive Oklahoma attorneys general to hold Arkansan poultry companies responsible in court for phosphorus pollution in the Illinois River watershed.
When contacted Friday afternoon, the mayor of Decatur said he was unable to get an Advocate reporter in touch with someone from the wastewater department by the end of the day, and that he couldn’t comment until next week.
“In Tulsa’s view increased flow into the Waste Water Treatment Plant (“WWTP”) and discharge from the Decatur WWTP will only result in greater pollution to the watershed Tulsa utilizes for clean water and result in damage to the people of Oklahoma and Northwest Arkansas,” the city wrote in its Nov. 26 hearing request.
The city wrote that DEQ did not explain how any additional phosphorus that enters the watershed as a result of the higher flow would not harm water quality in the agency’s response to Tulsa’s comments on the permit modification. It asks the pollution control commission to vacate the permit changes and find that DEQ acted “arbitrarily and capriciously and contrary to law” when it granted the change.
A spokesperson for the Department of Energy and Environment, DEQ’s parent agency, did not respond to a request for comment on the permit appeal.
Decatur has a documented history of permit violations, with two consent orders with DEQ in the last ten years. Tulsa alleges in its appeal request that “Decatur is not actively working to address any of its exceedances or deficiencies.” DEQ’s 2024 consent order “came only after years of ignoring exceedances and Decatur as yet to reach compliance. Furthermore, it confounds logic to increase the flow into the plant without the existing plant coming into full compliance,” Tulsa wrote to DEQ.
According to data from the EPA, the amount of phosphorus discharged by the plant nearly tripled between 2010 and 2024. The majority of those increases have occurred since 2020. Incomplete 2025 data shows lower amounts of phosphorus compared to 2024. That data does not yet include November or December discharge data.
But Tulsa says there are still problems. Data collected by the city from Columbia Hollow Creek, where the Decatur plant discharges treated wastewater, showed “a substantial increase in the concentration of total phosphorus and the abundance of E. coli in samples” between April 2025 and September 2025 that indicate an existing, unaddressed issue at the Decatur plant. That data was not provided in the request.
In its October comments on the DEQ modification consent order, Tulsa threatened another lawsuit if Decatur’s permit modification was not overturned.
“Granting the permit as written will absolutely result in more phosphorus in the Eucha-Spavinaw watershed, a greatly enhanced risk of harm to the City Water Supply and will also result in litigation with Decatur and ADEQ,” the city wrote, asserting later that the communications from the Arkansas Department of Health amounted to concerns that “show the project is marginal on a good day, and at worst presents a potential for environmental disaster for the people of Northwest Arkansas and Northeast Oklahoma.”
Phosphorus flowing from Arkansas poultry growers into Oklahoma’s waters has remained a cause of contention throughout the 21st century — Attorney General Tim Griffin published an op-ed Friday blasting the long-running Illinois River watershed lawsuit in Talk Business and Politics.
“Arkansas will continue to oppose Oklahoma’s attempt to threaten our farmers, weaken our economy, and limit our sovereignty,” Griffin wrote in the op-ed, which was published days after Tyson said it may not enter into contracts with poultry growers in the watershed going forward unless Oklahoma backs off its demands in the long-running lawsuit.
A federal judge ruled in favor of Oklahoma in 2023, but still has not issued a final decision in the case — though he ruled earlier this year that the watershed still remained polluted, fifteen years after it went to trial. Oklahoma’s attorney general said at the time that the final decision could come by the end of 2025.
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Arkansas Advocate is part of States Newsroom, a nonprofit news network supported by grants and a coalition of donors as a 501c(3) public charity. Arkansas Advocate maintains editorial independence. Contact Editor Sonny Albarado for questions: info@arkansasadvocate.com.