Smithfield Foods Wastewater Treatment Discharge Exceeded Limits Aug. 15

On Aug. 15, Smithfield Foods reported its wastewater treatment plant had an upset. Consequently, ammonia concentrations in the discharge from their Sioux Falls facility are higher than the regulatory limits in their Surface Water Discharge Permit. Levels could pose threats to fish life, but no risks to human health.

In response, the South Dakota Department of Environment and Natural Resources (DENR) has dispatched staff to investigate and collect water quality samples. No impacts to fish or the aquatic system have been observed, but DENR will continue to monitor the river through the weekend. The specific cause of the increased ammonia concentrations remains under investigation; however, Smithfield Foods is taking steps to reduce the concentrations discharging to the Big Sioux River.

“At this point, it appears Smithfield Foods is responding appropriately to the situation,” said DENR Secretary Steve Pirner. “However, DENR will continue to monitor the situation as Smithfield works to bring the wastewater treatment facility back to normal operation.”

Smithfield Foods operates a pork production facility in Sioux Falls, employing about 3,500 people. Smithfield produces fresh pork, bacon, deli meats, hot dogs, and smoked meats marketed under brand names such as Smithfield®, Eckrich®, Nathan’s Famous®, Farmland®, Armour®, Cook’s®, and John Morrell®.

Smithfield operates a wastewater treatment plant in Sioux Falls to treat the wastewater generated by its operations. DENR requires Smithfield to sample its discharge and report any violations. For more information about DENR’s Surface Water Discharge permitting program visit