The Minnesota Pollution Control Agency released new information regarding its ongoing efforts to determine what caused a massive fish kill in Duluth’s Tischer Creek in August.
MPCA Communications Specialist Beverly Godfrey says the city of Duluth drained an estimated 1.7 million gallons of chloraminated water into the creek from the Woodland Reservoir over a 15-hour period as part of a maintenance operation for the city’s drinking water system. Chloraminated water is drinking water that has been treated with chloramine, a disinfectant that’s made by combining chlorine and ammonia.
Chloramine is more stable than chlorine, so it can protect water from bacterial regrowth for longer, it produces fewer disinfection byproducts than chlorine and has a less noticeable chlorine odor and taste.