In its investigation of the incident, the Missouri Department of Natural Resources found that Tyson’s pre-treatment plant in Monett received wastewater containing Alimet, a liquid poultry feed supplement from another Tyson operation in Aurora.
The waste was pre-treated at the Tyson plant and then discharged to the city’s sewage system. The compound killed the bacteria that process the wastewater effluent in Monett’s plant, causing virtually undiluted ammonia to flow into a nearby river.
Missouri’s Attorney General, Chris Koster, filed a six-count civil lawsuit against Tyson after the spill, seeking fines, compensation for damage to the stream and reimbursement for the costs of the state's investigation.
Under the terms of the agreement, Koster says Tyson has to pay $162,898 for natural resource damages and another $110,000 in civil penalties. Tyson will also pay to replace a bridge at an estimated cost of $210,000.
A spokesperson for Tyson Foods said: "We deeply regret the incident in Clear Creek, near Monett, Missouri, this past May. We’ve worked diligently and cooperatively with state and other authorities to make things right, including entering into a settlement agreement with the state.
Tyson Foods’ core values include serving as stewards of the environment - in Missouri and every community where we operate - and we take that obligation seriously.”
The attorney general added that Tyson has put procedures in place to avoid a repeat incident, including new practices to prevent and monitor animal feed discharges, adding more waste water training for employees and a company wide environmental operating system.
Koster also says the state will also have stricter oversight on the transportation of hazardous waste from Tyson's facilities. The state also retains the right to inspect the plants at any time.