CAFO Harms Fact Sheets
Nutrient pollution is a serious concern in an agricultural state like Missouri. Anyone who has tried to nuture a garden knows that phosphorus and nitrogen are necessary to sustain life and grow healthy food. However, too much of a good thing can cause serious problems in our waterways.
Excess phosphorus in our streams and lakes causes algae blooms (which look like green gunk in the water), reduces water clarity, and depletes the water of dissolved oxygen. These effects not only make water bodies less appealing for human recreation, but also can cause fish kills and other ecosystem disruptions.
Nitrogen and phosphorus pollution comes from farm animals, fertilizers, human sewage, cars, and storm-water runoff from highways and parking lots. In general, runoff from farms and urban areas causes the greatest problem, although sewage treatment plants are significant contributors as well.
When excess nitrogen and phosphorus enter waters from discharges, fertilizer run off, and other sources, they cause an explosion of algae or phytoplankton in the water. The algae quickly deplete the dissolved oxygen in the water and then die themselves. Fish and other water creatures leave the polluted area, if they can, or die, if they cannot escape. The resulting dead zone is known as a hypoxic zone. These dead zones occur in lakes and even in streams.
Nitrogen pollution from Midwestern farms contributes to the massive annual “dead zone” in the Gulf of Mexico . In 2007, the dead zone covered 7,900 square miles, an area comparable to the size of New Jersey . At high levels, nitrogen in drinking water can even threaten human health, by interfering with the blood’s ability to transfer oxygen to cells. Nitrogen pollution of well water is responsible for “blue baby” syndrome, a life threatening condition present.
Technologies exist to remove nitrogen and phosphorus from sewage plant discharges, and best management practices such as buffer strips and wetland restoration can reduce pollution from farm runoff.
MCE has been working with the Mississippi River Collaborative and the Interdisciplinary Environmental Clinic at Washington University School of Law to secure the adoption of nitrogen and phosphorus pollution limits in our state.
