Greenspace: State asking for best ideas on clean water
Know any good ways to clean our water? The Minnesota Pollution Control Agency would love to hear your ideas and add them to its nutrient reduction strategy.
Between now and Dec. 18, the MPCA is looking for help on its draft of how to keep polluting nutrients out of our waterways.
"There's nitrogen and phosphorous," said Wayne Anderson, nutrient strategy manager for the Minnesota Pollution Control Agency. "Those are the two that are driving us to problematic water quality conditions."
In addition to the big two culprits, Anderson said potassium and a whole system of micronutrients also contribute to damaging our lakes and rivers.
From waste water in the cities to agriculture in rural areas, there's a wide range of human activities that contribute nutrients to the water supply. Those nutrients end up promoting the growth of plants and algae, sucking the oxygen out of the water.
And that nutrient pollution, Anderson said, isn't just ending up in Minnesota waters. According to the MPCA, Minnesota rivers drain into three major drainage basins: the Mississippi River and Gulf of Mexico, the Great Lakes, and Lake Winnipeg. While all three have water quality issues, the Gulf of Mexico is home to a significant region of low oxygen.
Anderson said the MPCA has effective strategies for controlling phosphorous pollution. Those include taking care of leaves and other yard waste in urban areas.
"We are making progress on phosphorous reduction," he said. "Those we want to push farther. But with nitrogen, we need new efforts."
Most nitrogen pollution comes from agriculture, Anderson said, a result of growing crops.
"One of the bi-products of farming is excess nitrogen washing out of the system," he said.
Nitrogen, a major component of fertilizer, moves at ground level through rain washing excess fertilizer across the landscape and into streams. It also moves underground through rainwater moving through soil. Typical soil in southeast Minnesota, Anderson said, is coarse and extremely pervious. "It washes past the root zone and through the soil," he said. There, he added, it gets in wells and drinking water.
That said, farmers are doing better today than even just 10 years ago, Anderson said. The key is to use fertilizer more efficiently, placing it at the right time and at the right amount. That, he said, avoids the excess nitrogen in the first place.
One of the keys to stop water moving both on and below the surface, Anderson said, is creating root barriers. "Corn and soybeans are in soil for three months," he said. "We need more cover crops."
Another key is planning deep root buffers on the strips of land bordering crops. Native prairie grasses are ideal for slowing the movement of water.
"It really takes everyone doing their part," Anderson said. That means homeowners in the city and farmers in the field. Those, and everyone in between, are the people the MPCA is looking for to help it improve its nutrient reduction strategy.
"The draft is meant to be a conversation starter," Anderson said. "We don't have all the answers."
Brian Todd is a Rochester freelance writer.
To check out the Minnesota Pollution Control Agency's nutrient reduction strategy, visit http://www.pca.state.mn.us/6kf4qq6