TOLEDO — Ohio and Michigan have agreed to sharply reduce phosphorus runoff blamed for a rash of harmful algae blooms on Lake Erie that have contaminated drinking water supplies and contributed to oxygen-deprived dead zones where fish can’t survive.
The two states along with Ontario, Canada, said Friday that they will work to cut the amount of phosphorus flowing into western Lake Erie by 40 percent within the next 10 years.
It’s a significant move to combat the algae blooms that have taken hold in the western third of the lake over the last decade and colored some of its waters a shade of green that’s drawn comparisons to pea soup and the Incredible Hulk.
Researchers have linked the toxic algae to phosphorus from farm fertilizers, livestock manure and sewage treatment plants that flows into rivers and streams draining into the lake.
Groups studying the algae blooms, including a U.S.-Canadian agency, began calling for a 40 percent reduction in phosphorus two years ago. That suggestion took on greater urgency last August after an algae outbreak contaminated public drinking water supplies for more than 400,000 people in Toledo and parts of southeastern Michigan.
The largest bloom came in the summer of 2011, stretching more than 100 miles — from Toledo to Cleveland.
Officials in the two states and Canada will develop plans on how to reach their goal to reduce the phosphorus runoff. They hope to start with a 20 percent reduction within the next five years.
“No one state owns the lake or the whole problem, nor can one state fix it,” said Craig Butler, director of the Ohio Environmental Protection Agency. “It took a generation to get here. If we can change this in 10 years, that’s pretty quick.”
Officials plan to sign the deal Saturday at the Council of Great Lakes Governors meeting in Canada.
The International Joint Commission said two years ago that urgent steps were needed to get control of the algae through a combination of regulations and voluntary actions.
Some of those steps have been put in place over the past year.
Ohio has new rules banning farmers in northwestern Ohio from spreading manure on frozen and rain-soaked fields and requiring training before farmers can use commercial fertilizers. The state also is increasing monitoring of wastewater plants. Michigan, meanwhile, has a voluntary program to help farmers reduce pollution that goes into waterways.
The two states along with Indiana also will begin sharing $17.5 million from the federal government to reduce farm field runoff by planting strips of grass or cover crops that help soil absorb and filter phosphorus.