Fish Kill Event - Unnamed Tributary to Floyd River
West Floyd Park, Le Mars
- Event ID
- 969
- Date of Kill
- 5/31/2018
- Waterbody Type
- River/Stream
- Cause Origin
- Anthropogenic
- Cause
- Ammonia/Fertilizer
- Mode
- Spill
- Magnitude
- 1 (1 - 100 fish killed)
- Kill Length
- not enumerated
- County
- Plymouth
- ESD Field Office
- FO 3
- Fisheries Office
- Spirit Lake Hatchery
- LongDD
- -96.18113
- LatDD
- 42.79108
- Created Date
- 3/28/2019 8:54:02 AM
- Last Update
- 3/28/2019 8:54:02 AM
We were notified of an ammonia release from a cooling unit from NOR-AM Cold Storage in Le Mars that occurred at about 5:00 P.M. on 5/31/18. The ammonia, mixed with water, went down a roof drain, to the storm sewer and to a small tributary to the Floyd River.
Upon investigation, about 50 dead fish were observed in the tributary/storm sewer outlet near West Floyd Park in Le Mars. In fact, people observing ball games last night reported an ammonia odor to the City, hence the discovery.
An employee of NOR-AM was performing maintenance on an evaporator unit. An open valve allowed ammonia to escape the unit. It is estimated that 21 pounds ammonia, in total, was release. This was enough to cause the small fish kill of minnows and chubs.
ES staff measure a high of 7.5 ppm ammonia near the ball park. There was no detectable impact on the Floyd River, nor is there expected to be. The contaminated water (about 440 gallons) was pumped from the storm sewer/tributary.