In Minnesota, warning flags are up because harmful nitrates are contaminating surface waters and private wells. See McVan, Agriculture pollutes underground drinking water in Minnesota. Well owners pay the price. In April a formal petition was submitted to the U.S. EPA by the Minnesota Center for Environmental Advocacy (MCEA) and other environmental groups raising the alarm that nitrate contamination in southeastern Minnesota waters is an “imminent and substantial endangerment to public health.” Land applications of manure from animal feedlots and excessive use of nitrate fertilizers in this area must be reduced to protect public health.
The state’s health standard for nitrates in drinking water is 10 mg/L. Many wells exceed this level, but the state does not test nor does it oversee water quality of private drinking water wells. Studies suggest the standard should be reduced to 2 mg/L. There is some good news: nitrate levels in 96.7 % of public drinking water supplies are in the 0-3 mg/L range; less than 1% of public water supplies have 5-10 mg/L; and none exceed 10.
What about other waters – lakes, wetlands, and streams where a diversity of awe-inspiring underwater creatures depend on clean water? To date, the Minnesota Pollution Control Agency (MPCA) has no water quality standard for nitrates in surface waters – yet they have documented elevated nitrates in some streams, lakes and urban ponds. In 2010, the agency was given a state grant by the Legislature to create a water quality standard for nitrates in surface waters, but they didn’t.
In 2012 MPCA and other agencies produced a major report on nitrogen in Minnesota, but not about its environmental impacts. A stunning 158 million pounds of nitrates flow every year from Minnesota landscapes into the Mississippi River, 73% of this coming from agricultural sources – crop land and feed lots.
In 2022, MPCA water quality scientists released a comprehensive report in which they assembled and analyzed information from national scientific studies that tested the impacts of nitrates on various aquatic species. The agency’s review lists aquatic invertebrates impaired by nitrates: caddisfly, mayfly, and midge larvae are the most sensitive, followed by a crustacean amphipod, a freshwater mussel, a fingernail clam, tiny crustacean daphnia (my favorite) and a stonefly. Nitrates can impact or kill lake trout and other cold water fish, disrupt fish hormonal systems, harm frogs and freshwater mussel reproduction.
MPCA proposes a water quality standard for protecting aquatic life at 8 mg./L for most surface waters and 5 mg./L for cold waters. Let’s hope the Agency moves forward in its rule-making process and monitors state waters sooner rather than later. Stay tuned.
Why isn’t agricultural runoff regulated under the Federal Clean Water Act (CWA)?
In my view, discharges from tiled farm land across the state should be regulated to protect all waters of the state. In many ways, industrial agriculture has been ‘off the hook,’ not responsible for its impacts. As said, 73% of Minnesota’s annual 150 million pounds of nitrates released into the Mississippi comes from agricultural land. The big elephant in the room is a clause in the Clean Water Act that states it regulates point source discharges of pollutants, namely wastewater treatment plants and industries that discharge into rivers, but not non-point pollutants that flow off the landscape. This ties the hands of state water pollution regulators. Nonpoint source pollution is the biggest threat to water quality in the United States today, said one scientist in the Ecology Law Quarterly article “Realigning the Clean Water Act. Comprehensive Treatment of Nonpoint Source Pollution.”
[image_caption]Judy Helgen[/image_caption]
Globally, excessive agricultural use of nitrogen has exceeded “planetary boundaries” (Nature, 2022); this continues to worsen the Dead Zone in the Gulf of Mexico, where tens of thousands of dead fish recently washed on shore in Texas. Action is needed on local, state and national levels because nitrates keep increasing in surface waters and in private drinking water wells. I applaud the dedicated people who are working hard to raise awareness and protect our waters.
Judy Helgen is a retired research scientist from the Minnesota Pollution Control Agency. She worked on biological monitoring of wetlands water quality based on aquatic invertebrate communities and led the investigation into widespread deformed frogs. She lives in Falcon Heights.
Regulate farmers? Heck no, we need to “Let Farmers Farm!”
Those wise rural folks, who’ve been on their land for generations, they love their land, and wouldn’t do anything short sighted. Amiright?
We need to reject this Freedom Last agenda.
The distinction between point-source and non-point pollution is a little slippery. It’s point-source when discharged from a wastewater treatment plant, but it’s non-point when applied by thousands of farmers, to then run down into streams, wetlands, rivers and lakes.
It’s point-source when it comes out of the fertilizer manufacturing plant, bit it isn’t yet pollution. Nitrates coming out of the fertilizer plant don’t become pollutants until they exit the particular farm’s property line. A farm could be a point-source polluter if you could measure and analyze its runoff, but that’s not usually practical, and may not even possible.
It’s a kind of shell game in which the EPA is charged with protecting our waters but is specifically disempowered from doing so. The belief that we have to put up with it is just learned helplessness.
The state can control nitrates in public waters. The question is will the state do so?
A lot of the nitrates from runoff comes from industrial “farms” a/k/a CAFOs. The waste generated by these livestock feeding operations generate more manure than many cities. But treatment of this waste usually consists of some relatively short term suspension in holding ponds before the waste is then spread on fields where the nitrates and other remaining pollutants become part of a “nonpoint source” of pollution. It’s becoming clear that some of this runoff also seeps into groundwater where it can and has contaminated rural wells.
There’s no question that the land is better cared for when there are people living on it and the agricultural land is not simply owned by passive, absentee corporations. But out government’s policies have brought us to this state where to farm is to be forced into a corporatized industrial business model, borrowing heavily for the latest technology and confining animals inhumanely in small feed operations for meat, eggs or dairy. It’s not healthy, it’s not sustainable and it’s terrible for the ecosystem. The state must control nitrates and it must end CAFO permitting.