Posted March 19, 2017
Water pollution regulations in the U.S. may change following a recent White House executive order, a shift that could have an impact on river ecology and agricultural practices in River Falls.
The Clean Water Act has been around since 1948 and establishes the basic structure for regulating water pollutants in the U.S. Specifically, it protects waters defined as “navigable.” According to the U.S. Army Corps of Engineers, navigable waters are those that are used or can be used for transport, and which are subject to the ebb and flow of the tide.
The concern, however, is that there are non-navigable waters in the U.S. that also need protection. In response to this concern, the “Waters of the United States” rule was adopted in 2015 during the Obama Administration as a way of expanding the water types that qualify for protection under the Clean Water Act.
Included under the “Waters of the United States” rule are tributaries (defined by the presence of a water bed, banks and an ordinary high water mark), adjacent waters (bordering waters such as wetlands and lakes), and case-specific waters that have a significant impact on nearby navigable systems. It does not include groundwater, erosional features or stormwater control. It also does not include ditches, unless the ditches are in fact tributaries that have been relocated or excavated.
The executive order signed Feb. 28 by President Donald Trump opens up the possibility that the definition of protected water in the U.S. will change. As of yet, no decisions have been made. Kathy Bartilson from the Wisconsin Department of Natural Resources (DNR) said that, “So far, we haven’t really had time to assess the impact of the most recent proposals.”
In River Falls, any changes to the rule would most likely be felt in the agricultural community, as well as in the ecology of the Kinnickinnic River. Agriculture and river ecology are very closely connected, particularly during large storm events.
Under normal circumstances, said UW-River Falls Professor Kerry Keen, the River Falls area has an effective natural filtration system. River Falls sits on a layer of rock called the Jordan aquifer, which is about 100 feet below the surface. The layer is made of porous sandstone, and surface water can slowly seep through it and filter out most contaminants before it’s released back into the Kinni. Local wells are typically sunk into this layer, and so the drinking water in River Falls, Keen said, is relatively clean.
The problem, said UWRF Assistant Professor Jill Coleman-Wasik, is that this sandstone layer doesn’t work quickly enough when there’s a large rain event. Contaminants such as phosphorous and sediment are usually relatively low in the Kinni, she said, but during storms, “it’s way out of bounds.” The most common and most impactful contaminants that typically work their way into the Kinni are phosphorous and nitrogen, she said, and both are typically spread onto fields as fertilizers.
Phosphorous, when it gets into a watershed, can set off a domino reaction up the food chain. In a lake, algae will feed on it and go rampant, causing large blooms of scummy green goop on the surface of the water that can potentially shade out plant species on the bottom. When the algae dies, it is then fed upon by bacteria, which in turn suck the oxygen from the water and suffocate the local fish populations. In rivers, however, this is less of a problem because of the constant movement of the water. However, food chains can be affected as the phosphorous allows certain algae communities to take off, which can be harmful in the long term.
Nitrogen, of the two pollutants, is the more directly harmful to humans, Coleman-Wasik said. Nitrate is a form of nitrogen that, when ingested into the human body, tends to bind to hemoglobin in the blood. Hemoglobin’s job is to deliver oxygen to the cells of the body, but if nitrate binds to it and leaves no room for oxygen, a person can effectively suffocate. For adults, the amount of nitrate that can be safely consumed is around 10 milligrams per liter of water, according to a 1977 report from the National Academy of Science. In the Kinni, Coleman-Wasik said, the nitrate concentration is hovering right around that level. It is a doable level for healthy adults who get their water from multiple sources, she said, but the effects can be more pronounced in infants who drink nothing but baby formula.
Phosphorous and nitrate most often make their way into the Kinni when a big storm washes them off agricultural fields, into streambeds that are otherwise dry, and on into the river. The fear in the agricultural world, Coleman-Wasik said, is that these dry-run streambeds will be included under the Clean Water Rule, and that farmers will be subjected to more intensive regulation.
Sue Porter, a nutrient management specialist with the Wisconsin Department of Agriculture in Madison, said that U.S. Environmental Protection Agency rules are often very difficult to work with in the agricultural industry because the federal laws are often layered on top of state-level laws. Sometimes the rules are contradictory, or are inconsistently applied from state to state.
“If we all had the same message it would be a lot easier to implement and much easier for everyone to know what to do,” Porter said.
However, it is in the best interests of farmers to be mindful of how pollutants run off their crops, Porter said. The chemicals that ultimately wash into a water system are expensive, and they don’t serve their purpose when they’re being carried off into a river. Topsoil, similarly, is very valuable, and maintaining green buffers to keep it in place is a practice that can benefit both the farmer and the local river systems.
“I don’t think that producers are interested in getting rid of all their grassed waterways,” said Coleman-Wasik. “They’re not necessarily doing that because the Clean Water Act tells them to.”