Nutrient pollution | St. Louis Public Radio

Nutrient pollution

A view of Lake Taneycomo in February 2018.
Eli Chen | St. Louis Public Radio

On a bright, brisk winter day in Branson, Mo., several dedicated fishermen tried to catch trout in Lake Taneycomo, a fast-moving, ribbon-shaped lake that snakes around the city.

The water appeared clear, but the lake has some ongoing issues, said David Casaletto, executive director of Ozarks Water Watch, a water quality group. For example, heavy rains in the summer have caused low levels of dissolved oxygen, which has hurt the trout population.

Under a recently proposed water quality rule from the Environmental Protection Agency, Lake Taneycomo, Mark Twain Lake and Lake of the Ozarks are among 113 lakes and reservoirs in Missouri that would be defined as “impaired” or too polluted for human use.

An aerial view of Lake of the Ozarks.
Courtesy Lake of the Ozarks Convention & Visitor Bureau

The Environmental Protection Agency has released its proposal for tackling polluted runoff in Missouri's largest lakes.

But environmentalists say the EPA's plan, like the state's plan that was released in October, is not strong enough to address pollution. 

Missouri does not set limits for nitrogen and phosphorus, nutrients that can cause fish kills and create dead zones in excessive quantities. A Clean Water Act settlement last year with the Missouri Coalition for the Environment required the EPA to devise a rule to regulate nutrient pollution in Missouri's lakes by Dec. 15, unless the Missouri Department of Natural Resources filed its own proposal by that date. The state failed to submit a plan by the deadline. 

An aerial view of Lake of the Ozarks.
Courtesy Lake of the Ozarks Convention & Visitor Bureau

Missouri will soon adopt new regulations to clean up the state’s 150 large lakes and reservoirs.

But environmentalists contend the state’s plan won’t be strong enough to address pollution caused by harmful nutrients.

Missouri currently does not set limits on nitrogen and phosphorus. A combination of agricultural runoff, stormwater runoff, sewage treatment plant discharges and other sources can cause an excessive amount of the nutrients to enter lakes, rivers and streams. Nutrient pollution can render bodies of water unsuitable for drinking and recreation, cause fish kills, and drag down oxygen levels to create “dead zones,” similar to the one that exists in the Gulf of Mexico. 

A dead zone with sediment from the Mississippi River carries fertilizer to the Gulf of Mexico.
National Oceanic and Atmospheric Administration

This story was updated to clarify how the EPA would proceed. 

The Environmental Protection Agency will  propose regulations on nutrient pollution by mid-December 2017 to settle a lawsuit filed by an environmental group in U.S. District Court. 

The Missouri Coalition for the Environment filed a lawsuit against the EPA in February for not adequately addressing the issue of nutrient pollution through the Clean Water Act. The EPA has agreed to propose rules by next year, unless the agency approves criteria submitted by the state before the deadline. 

Nitrogen, phosphorus and other nutrients enter waterways through fertilizer runoff and sewage treatment plant discharges. An overabundance of such nutrients have caused fish kills, harmful algal blooms and dead zones along the Mississippi River.

A dead zone with sediment from the Mississippi River carries fertilizer to the Gulf of Mexico.
National Oceanic and Atmospheric Administration

Environmental advocates are calling on the Environmental Protection Agency to manage nutrient pollution from states that border the Mississippi River. 

The Mississippi River Collaborative, a group of environmental policy experts, recently released a new report that describes how the 10 states along the river are not making progress in reducing the amounts of nitrogen and phosphorus that eventually make its way down to the Gulf of Mexico Dead Zone.