DUBUQUE—Wednesday afternoon, DNR fisheries staff found freshly killed fish at the site of a fertilizer spill in Dubuque, indicating there is ongoing pollution going into Bee Branch pond.
Working with an environmental contractor, Gavilon Grain has developed a three-pronged plan to end ammonia contamination at the site.
First, they plan to pump air into the southeast corner of the pond, to help volatilize remaining ammonia. Second, they plan to recirculate water in the affected area, which should help dilute the ammonia concentration. Finally, they’ve asked permission from DNR to flush the storm drain to mobilize any ammonia left in the system.
The original spill occurred after a pump was left running while transferring fertilizer from a barge on June 18. An estimated 432,000 gallons of liquid fertilizer overflowed from above ground storage tanks near 1200 Kerper Boulevard.
During a follow up inspection on June 22, DNR found elevated ammonia levels and dead fish in the southeast corner of Bee Branch Pond. DNR fisheries staff conducted a fish count and 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.
Yesterday, June 24, fisheries staff found additional dead fish and evidence of a larger mussel die-off.
The DNR will conduct another fish count, continue to monitor cleanup and consider appropriate enforcement action, including fish restitution.