Phosphorus Dispute Flares Up Again as Tulsa Fights Arkansas Plant Expansion
Phosphorus
10 December 2025 at 12:00
Phosphorus
10 December 2025 at 12:00
Tulsa, Oklahoma has launched a formal challenge against an Arkansas environmental agency's decision to allow a significant expansion of a wastewater treatment plant that discharges into the upstream watershed supplying Tulsa's drinking water. The core of the dispute centers on fears of increased phosphorus pollution flowing into the sensitive lake system that provides water for the Oklahoma city.
The plant, located in Decatur, Arkansas, would see its permitted capacity rise by over 1.5 million gallons per day. Tulsa officials argue this expansion should be blocked until the facility, which has a history of regulatory violations, can prove it will handle the increased flow without sending more pollutants downstream. Their primary concern is phosphorus, a nutrient that can fuel harmful algal blooms and degrade water quality in the lakes Tulsa relies on.
This conflict is the latest chapter in a decades-long battle over water quality. In 2001, Tulsa sued Decatur and several poultry companies, alleging their discharges polluted Lakes Eucha and Spavinaw with phosphorus. A 2003 federal court settlement resulted from that lawsuit. Tulsa now contends that approving the plant's expansion violates the terms of that old agreement, as the increased volume will likely lead to more phosphorus entering the shared watershed.
Environmental data underscores Tulsa's concerns. According to the U.S. Environmental Protection Agency, the amount of phosphorus discharged from the Decatur plant nearly tripled between 2010 and 2024. While incomplete 2025 figures show a recent decrease, Tulsa points to its own monitoring data from late 2025, which indicates a "substantial increase" in phosphorus concentrations in the creek receiving the plant's outflow.
In its legal challenge, Tulsa accuses the Arkansas Department of Energy and Environment (the parent agency of the permitting body) of acting "arbitrarily and capriciously" by not adequately explaining how the higher wastewater flow would prevent additional phosphorus pollution. The city has threatened new litigation if the permit modification is not revoked.
This local permit fight is set against the backdrop of a much larger, ongoing interstate legal battle. Oklahoma has sued poultry companies in federal court over phosphorus pollution in the neighboring Illinois River watershed—a separate but related case that has dragged on for over 15 years. An Arkansas state official recently criticized that lawsuit, framing it as an attack on the state's farmers and economy.
The outcome of Tulsa's appeal will test the enforcement of historical environmental settlements and highlight the ongoing tension between upstream economic activity and downstream water security, with the element phosphorus remaining the central point of contention.
Source:
