At the Environmental Protection Agency website, there's this on the page Basic Information about Nonpoint Source (NPS) Pollution:
NPS pollution generally results from land runoff, precipitation, atmospheric deposition, drainage, seepage or hydrologic modification. NPS pollution, unlike pollution from industrial and sewage treatment plants, comes from many diffuse sources. NPS pollution is caused by rainfall or snowmelt moving over and through the ground. As the runoff moves, it picks up and carries away natural and human-made pollutants, finally depositing them into lakes, rivers, wetlands, coastal waters and ground waters.
Nonpoint source pollution can include:
- Excess fertilizers, herbicides and insecticides from agricultural lands and residential areas
- Oil, grease and toxic chemicals from urban runoff and energy production
- Sediment from improperly managed construction sites, crop and forest lands, and eroding streambanks
- Salt from irrigation practices and acid drainage from abandoned mines
- Bacteria and nutrients from livestock, pet wastes and faulty septic systems
- Atmospheric deposition and hydromodification
States report that nonpoint source pollution is the leading remaining cause of water quality problems. The effects of nonpoint source pollutants on specific waters vary and may not always be fully assessed. However, we know that these pollutants have harmful effects on drinking water supplies, recreation, fisheries and wildlife. . . .
That seems to describe circumstances behind a large fish kill last summer in Winona County, if we correctly read a news release just out from the Minnesota DNR.
Back in September, Bluestem posted in Winona County citizens, LSP give Walz letter about July 26 Upper Rush Creek fish kill:
Two news reports jumped out in our feed yesterday: Dené K. Dryden's Winona County residents ask Gov. Walz for investigation on recent fish kills at the Rochester Post Bulletin and Bill Strande's Letter to Gov. Walz demands action on fish kills at KARE-11.
Dryden outlines the problem:
Winona County residents and Land Stewardship Project members on Wednesday delivered a letter to Gov. Tim Walz in St. Paul calling for action on fish kills in the county over the past several years.
"It's kind of becoming an annual pattern, based on what our members in the area are telling us," said Matthew Sheets, a policy organizer with Land Stewardship Project. "These fish kills keep happening in the region around Lewiston and Winona County, but folks are consistently not getting answers when things are investigated."
As previously reported by the Post Bulletin , an estimated 2,500 fish were found dead in the upper end of Rush Creek north of Interstate 90 near Lewiston on July 26. An estimated 2,500 fish were killed; most were brown trout.
Fish kills have occurred in other water bodies around the area in 2021, 2019, 2018, 2017 and 2015.
On Thursday, the Minnesota Department of Natural Resources issued the following press release, Investigation finds rainfall-driven runoff likely to blame for summertime fish kill in Rush Creek near Lewiston:
According to a multi-agency investigation led by the Minnesota Pollution Control Agency (MPCA), several factors likely contributed to the July 2022 death of 2,500 fish in Winona County, including storm runoff, warm temperatures, and water conditions in the creek. Investigators from the MPCA, Department of Natural Resources, Department of Agriculture, and Winona County determined that the fish kill did not occur naturally, but could not pinpoint the exact cause, which is frequently the case with fish kills.
The incident which was discovered on July 26, 2022, occurred within a two-mile stretch of Rush Creek south of Lewiston, between Winona County Roads 29 and 90. Seventy-five percent of fish killed were brown trout while the remaining species included white sucker and mottled sculpin.
During the course of the investigation, field crews conducted visual observations, took field measurements, and collected water chemistry samples as well as macroinvertebrates at multiple locations near the fish kill. The investigation team also contacted more than 100 landowners located within a 10-square mile area upstream of the fish kill and conducted extensive review of manure land application records, as well as in-field land application inspections.
Investigators did not find evidence of a direct discharge of pollutants to Rush Creek.
They concluded that recent upstream applications of manure and pesticides combined with low-flow conditions in the creek prior to rainfall on July 23 may have led to the fish kill.
“We share the public’s frustration around events like this that impact hundreds of fish and oftentimes don’t point to any one cause,” said Dana Vanderbosch, assistant commissioner for water policy and agriculture. “We often hear of fish kills several hours, or even days, after they occurred and the pollution in the water has diluted and washed downstream. We have had numerous meetings with members of the community to explain challenges around these investigations, and we will continue to work with residents, businesses, and landowners on strategies to reduce the risk of future fish kills.”
While there is no direct cause determined for this event, inspections completed during the investigation uncovered violations of rules by facilities within the Rush Creek watershed. The MPCA issued notices of violation to two facilities in Lewiston for incomplete recordkeeping and violating setback requirements from sinkholes, including applying manure within 50 feet of a sinkhole and within 300 feet of a special protection area.
In 2022, state agencies received reports of approximately 150 fish kills, most of which were much smaller in scale than the Rush Creek event. Additional fish kills likely went unnoticed or unreported. Unfortunately, the exact cause of most fish kills cannot be determined, but environmental factors including those caused by human activities often contribute. Poor environmental conditions can lead to a higher incidence of disease in otherwise healthy fish populations.
To reduce the potential for fish kills, state agencies will soon launch proactive communication efforts aimed at local businesses, farmers, communities, stakeholders, and residents. The campaign will include sharing information about how to consider weather forecasts in advance of applying manure, fertilizers, and pesticides. Agencies will also work with landowners in sensitive areas and watersheds to better implement best management practices to reduce runoff to rivers, streams, and creeks.
It is critical for anyone that observes a fish kill to report it immediately to increase the chances of identifying the cause or source for a fish kill. If you see something, contact the State Duty Officer at 800-422-0798. If there is an immediate threat to life or property, call 911 first.
The Rochester Post Bulletin has more in Last summer's fish kill near Lewiston likely caused by rainfall runoff, MPCA says. Dryden reports:
“We share the public’s frustration around events like this that impact hundreds of fish and oftentimes don’t point to any one cause,” said Dana Vanderbosch, MPCA assistant commissioner for water policy and agriculture. “We have had numerous meetings with members of the community to explain challenges around these investigations, and we will continue to work with residents, businesses, and landowners on strategies to reduce the risk of future fish kills.”
Well, that'll work.
Photo: Trout washed up dead in Rush Creek. A fish kill beginning July 26, 2022, on the creek has led to the death of more than 2,500 fish. Contributed to Rochester Post Bulletin/ Carl Berberich. Dryden report
If you appreciate Bluestem Prairie, you can mail contributions (payable to Sally Jo Sorensen, 600 Maple Street, Summit SD 57266) or use the paypal button in the upper right hand corner of this post.
Or you can contribute via this link to paypal; use email [email protected] as recipient.
I'm on Venmo for those who prefer to use this service: @Sally-Sorensen-6
Comments