This week, scientists from the Louisiana Universities Marine Consortium completed their annual measurement of the Gulf of Mexico’s Dead Zone, which measured 5,800 square miles, larger than the state of Connecticut.
The Dead Zone is an area of water at the mouth of the Mississippi River which is oxygen-deprived due to excess nitrogen and phosphorus pollution coming primarily from agricultural sources throughout the Basin as far north as the River’s source in Minnesota, and including the state of Iowa.
In addition to causing the Dead Zone in the Gulf, nitrogen and phosphorus pollution harms waters throughout the Mississippi River Basin and its tributaries, threatening wildlife and recreation as well as the safety of drinking water.
“Record-high nitrate pollution levels in May through July have forced the Des Moines Water Works to use a nitrate removal system and blend water from other sources just to deliver safe drinking water to over 500,000 Iowans,” said Susan Heathcote, water program director for the Iowa Environmental Council, a member of the Mississippi River Collaborative.
The annual Dead Zone measurement makes the size of the nitrogen and phosphorous pollution problem in the Mississippi River Basin clear, and Iowa’s contribution of nitrogen and phosphorous that feeds this problem is among the largest of any state.
“Giving a voice to the majority of Iowans who share this concern, we have repeatedly called on state leaders to set clear, measurable goals for reducing Iowa’s contribution to the Dead Zone,” said Ralph Rosenberg, the Council’s executive Director. “Iowa’s Nutrient Reduction Strategy, state government’s proposed plan, does not currently explain how this will take place, when it will take place, and when many stakeholders–those who drink from Iowa’s waters or fish or canoe–will know that progress is being made.”
The consequences of nitrogen and phosphorous pollution are not limited to the Dead Zone; they pose a serious problem in Iowa’s waters. This year, significant threats to safe drinking water, high rates of soil erosion, and the presence of harmful algae blooms in Iowa’s lakes all suggest additional conservation action would benefit Iowans as well as those living downstream.
Despite voluntary initiatives to reduce nutrient pollution which have been encouraged by EPA and other states, the Dead Zone has only grown bigger. This lack of effective action forced members of the Mississippi River Collaborative to file suit against EPA in 2012 in an attempt to get the agency to set and enforce numeric standards for nitrogen and phosphorus pollution.
Although the EPA called on states to develop numeric nitrogen and phosphorous limits 15 years ago, the agency has repeatedly pushed back deadlines for reducing Dead Zone-causing pollution.
Nitrogen and phosphorus pollution is a key concern for the Mississippi River Collaborative, a partnership of environmental organizations and legal centers including the Iowa Environmental Council that works to protect the Mississippi River and its tributaries.