DUBUQUE—During a follow-up check at the site of a fertilizer spill Monday, the DNR found elevated ammonia levels and dead fish in the southeast corner of Bee Branch Pond in Dubuque.
When inspecting the site June 22, DNR staff found high ammonia levels in rainwater running off the Gavilon Grain parking lot. While the main site of a 32 percent nitrogen fertilizer spill that occurred June 18 is contained, DNR staff think recent rains may have washed fertilizer into the pond.
Gavilon staff is working with an environmental contractor to ensure storm water is contained and pumped up. They are also checking for underground piping that may drain to the pond.
DNR fisheries and law enforcement staff are on site to conduct a fish count. So far, they’ve found mostly game fish including dead bluegill, walleye, largemouth bass, northern pike and channel catfish. Other dead species noted were various minnows, common carp and several giant floater mussels.
The original spill occurred after a pump was left running while transferring fertilizer from a barge on June 18. Initially, an estimated 1 million gallons of liquid fertilizer overflowed from above ground storage tanks near 1200 Kerper Boulevard. Based on company records and fertilizer remaining in storage tanks, 432,000 gallons is a more accurate estimate.
The DNR will continue to monitor cleanup and consider appropriate enforcement action, including fish restitution.