Michael Brun, Forum News Service, Published November 29 2013
Minnesota agency seeks feedback on water pollution planRED WING, Minn. – Minnesota lakes and rivers have a nutrient pollution problem, and the Minnesota Pollution Control Agency is putting together a plan to help clean them up.
The biggest culprits are nitrogen and phosphorous, which not only harm lakes, rivers and groundwater in Minnesota but also wash downstream via the Mississippi River and add to a dead zone in the Gulf of Mexico.
The MPCA’s Nutrient Reduction Strategy aims to reduce nitrogen levels in the Mississippi River basin by 20 percent and phosphorous by 35 percent over the next 12 years.
“The strategy looks at the big picture of where the nutrients are coming from and how to reduce them,” said David Wall, a MPCA hydrologist who has been studying the effects of nitrogen in Minnesota waters.
Although some of the nutrient pollution is caused by streambank erosion, the bulk of it comes from human activity, including agricultural runoff and municipal wastewater, Wall said. In particular, nitrogen pollution in Lake Pepin is largely caused by tile drainage systems on watershed cropland.
Once in place, the strategy will serve as a guide for government agencies, businesses and residents to adjust programs and behaviors to reduce the amount of nutrients getting into the water, according to the MPCA.
The first phase will focus on improving wastewater treatment practices and getting farmers across the state to use fertilizer and manure more efficiently, said Wayne Anderson, strategy manager with the MPCA.
Other solutions outlined in the draft include increasing the use of cover crops on Minnesota fields and installing controlled drainage systems.
Reducing excess nutrients will preserve aquatic life and the recreational value of lakes and rivers in the state, the MPCA says. A buildup of nutrients promotes the growth of algal blooms, leading to low oxygen levels and fish kills.
Keeping nitrogen pollution in check also will protect public health by maintaining groundwater, which supplies drinking water to most Minnesotans, Anderson said.
The state’s long-term goal is to reduce nitrogen and phosphorous in the Mississippi River basin by 45 percent each.
“It’s going to take changes on millions of acres of land,” Wall said. “It’s going to take some time.”
A downstream problem
Beyond state waters, nutrient pollution from Minnesota also flows into Lake Winnipeg, Lake Superior and the Gulf of Mexico. The Mississippi River alone carries more than 200 million pounds of nitrogen out of the state each year, the MPCA says.
Minnesota is the source of about 6 percent of all nitrogen washing into the Gulf of Mexico, Wall said, adding that the Nutrient Reduction Strategy is about the state “doing our fair share” to reduce that figure.
Along with the MPCA, the Minnesota Department of Natural Resources, Metropolitan Council, Department of Health, and several other state and federal agencies helped develop the strategy.
The public comment period closes Dec. 18 and, depending on the amount of feedback received, the MPCA says it plans to finalize the strategy draft by the end of the year.