Floating weed harvesters have opened passages through Dane County Wisconsin’s dense tangles of underwater plants for about 50 years. The barges wield rotating cutting bars like those on farm combines to cut a submerged crop that is fertilized too well by runoff of nutrients like dairy manure. Each spring, the county launches a flotilla of
The dead zone in the Gulf of Mexico, which is believed to have been around since the 1970’s, is now an estimated 6,474 square miles of water unable to support marine life. Government and independent scientists believe nutrient runoff is the main cause of the dead zone. Pollutants such as nitrogen and phosphorus flow into
Chicago officials boast that the Stickney Water Reclamation Plant is one of the world’s largest sewer treatment plants, handling the waste of 2.3 million people. The Stickney Water Reclamation is the biggest single source of phosphorus in the entire region that drains into the Mississippi River. Combined with other sewage plant releases a state task
An estimated 9 to 10 percent of Wisconsin wells have tested over safe limits for nitrate. Studies have estimated that 90% of nitrate in groundwater comes from spreading of synthetic fertilizers and dairy manure on farm fields, with most of the remainder from septic systems. Nitrate behaves differently. Relatively little lingers near roots where it
