Pending lab results, it appears the likely source of the discharge causing the fish kill is Sioux-Preme Packing Company, located just south of Sioux Center. The DNR continues to investigate the reason for the discharge.
The fish kill was reported to the DNR on Monday after a resident noticed stressed fish in the stream over the Oct. 27th weekend.
DNR staff found elevated ammonia levels and thousands of dead fish, including game fish, for at least nine miles downstream of the plant. Fisheries staff conducted a second count of dead fish after fish continued to die on Tuesday and Wednesday, and were back on the site Thursday.
Sioux-Preme Packing Company has hired a contractor to pump and land apply water pooled in a tributary to the stream where ammonia has concentrated. The DNR will continue to monitor cleanup, and will pursue appropriate enforcement action and fish restitution.