The U.S. is falling short of its goals to stem Mississippi River pollution and shrink the dead zone it creates in the Gulf of Mexico.
Runoff from farm fields and water discharged from sewage treatment plants continue to pour into the Mississippi and states in the river's watershed need to accelerate efforts to cut the pollution, Environmental Protection Agency officials said Tuesday in Minneapolis as they presented a progress report on the cleanup.
In 2008, an EPA-led task force set a goal of reducing the dead zone to 5,000 square kilometers, which is still larger than Rhode Island, by 2015. This summer the area of depleted oxygen was the size of Connecticut.
"It's about three times the size we're looking for in terms of our ultimate goal," said Nancy Stoner, the EPA's acting assistant administrator for water, who co-chairs the task force. "It has not appreciably shrunk yet."
Stoner said the EPA and states have worked well together to come up with strategies to reduce the pollution, but she said it will take longer than officials had hoped to see results.
"It's a very ambitious goal, it's a very difficult goal, and even if we put in all the practices by 2015 that are necessary to reduce the dead zone, there's a lag time," she said. "That's one of the challenges we have: to continue to make progress, to continue to motivate people."
Each state has its own plan to help reach the overall goal. The Minnesota Pollution Control Agency will issue a draft of its updated plan next month and allow advocacy groups and members of the public to comment on it.
Iowa Secretary of Agriculture Bill Northey, who is the other task force co-chair, said states are just beginning to tackle nitrate pollution that results from farm runoff, which is rich in nutrients that end up cutting oxygen levels in a large area off the coast of Louisiana, killing most marine life.
"We've been talking about it, but actually showing farmers different practices has been very much more recent," he said.
Northey said it isn't as simple as changing fertilizer rates because nitrogen is also found in crop residue and organic matter.
"Nitrogen is in the organic matter that makes our wonderful soils very, very productive," Northey said. "So as our water goes through those soils, it'll pick up nitrogen, sometimes from fertilizer, sometimes from the residue, sometimes from the organic matter, and we have to manage all of that to try to reduce the amount of nitrogen that's leaving those farms."
Planting cover crops, which can grow during or outside of the normal growing season to improve the ecosystem, is one example of how farmers have contributed to the goal of reducing nitrate pollution, the EPA said in its progress report.
But farmer participation is voluntary, and Stoner said the EPA doesn't have regulatory authority to make it mandatory.
Some environmental groups have criticized the EPA for not doing more. In 2012 several groups, including the Natural Resources Defense Council, filed two lawsuits aimed at forcing EPA action on reducing the size of the dead zone.
Last week, a federal judge in New Orleans told the EPA it has six months to decide whether to set standards for nitrogen and phosphorous pollution or explain why they're not needed. (The Associated Press contributed to this report.)