April 9, 2012
This March, Prairie Rivers Network joined our Mississippi River Collaborative partners in launching two lawsuits against US EPA for their failure to regulate nutrient pollution.
Too many nutrients – a problem
Most people know that nitrogen and phosphorus are important nutrients for plants and animals. At high levels in water, however, the beneficial effects of these nutrients become problematic, and the nutrients are considered pollution.
Nitrate, a form of nitrogen, is toxic to people and other animals at high levels. A decade ago, Georgetown, Illinois had to abandon its drinking water reservoir because of high nitrate levels. Water suppliers for Decatur, Danville, and Streator had to install expensive ion exchange systems costing millions of dollars to remove nitrate from polluted reservoir water. Ongoing operation and maintenance expenses cost ratepayers tens to hundreds of thousands of dollars per year.
In rivers and lakes, nitrogen and phosphorus pollution stimulates excessive growth of algae, creating ugly mats or pea-soup scummy water. When the algae die, they rot. The bacteria that decompose them use up most or even all of the oxygen in the water, choking aquatic life. An enormous example of this problem is the “Dead Zone” that forms in the Gulf of Mexico every summer.
Especially in lakes and reservoirs, nutrient pollution can stimulate the growth of blue-green algae. This “pond scum” is unsightly and smells like vomit when it rots – enough to keep people from enjoying boating and swimming. The algae also sometimes release toxic chemicals into the water. Each summer, local communities throughout Minnesota, Wisconsin, Iowa, and Illinois are forced to officially close beaches because of the potential presence of blue-green algae toxins. The toxins can sicken or even kill people, pets, and livestock.