Report details ways to prevent, reduce cyanobacteria blooms in Lake Erie
A toxin produced by a kind of cyanobacteria contaminated Toledo's water supply over the weekend. It left 400,000 people without drinking water.
Blooms of cyanobacteria (sometimes referred to as blue-green algae) like these happen when excess nutrients — mostly phosphorus — run off into Lake Erie from farms and sewage treatment plants.
The International Joint Commission is an independent organization that gives advice to the U.S. and Canada on Great Lakes issues. Earlier this year, the IJC put out a report on how to prevent these blooms.
Raj Bejankiwar, of the Commission's Great Lakes Regional Office in Windsor, Ontario, is the lead scientist on that report.
Cyanobacteria blooms were a problem in the '60s and '70s, but then they went away and in the 2000s they started coming back. Bejankiwar says it's because of runoff, mainly from farms.
"We have to stop feeding algae their food, which is phosphorus. We use that extensively in the agriculture land and Toledo is right in the ground zero zone for algae, especially the Maumee River watershed." Bejankiwar adds that in the past few years, heavy storms have washed phosphorus-filled fertilizer from farms. "It ends up in the Maumee River and then finally in Lake Erie."
Immediate action needed
The IJC report recommends aggressive action from both the U.S. and Canadian governments to stymie the nutrient pollution in Lake Erie. Two years ago, an agreement set a 2018 goal for the reduction of nutrient pollution in Lake Erie but experts want that to happen sooner.
"There's some really good things that are going on both sides but especially one of the key things we heard over and over from the scientific community is that this winter application of manure and fertilizer when the ground is frozen is the key for triggering the algae blooms," said Bejankiwar. "So we are asking states to outright ban that practice because it's not an environmentally friendly option; it's not a good practice. So that is one of the key [measures] we wanted to see."
Scientists also want state governments to step in and declare waterways with too much phosphorus as "impaired waterways." If Michigan and Ohio were to use this terminology, defined in the Clean Water Act, it would jumpstart measures to develop a phosphorus total maximum daily load overseen by the EPA.
No easy answers
Last fall, a state task force in Ohio called for a 40% reduction of all forms of phosphorous going into the lake. However experts acknowledge that it's not simple to solve.
"Actually it's not a one bullet solution there; there is no one silver bullet solution. The key solutions, I think are needed right now is one, an outright ban on wintertime — and when the ground is frozen— application of fertilizers as well as manure. [The] second one is dealing with the increasing events of runoff, heavy storm events and heavy rain events."
Bejankiwar also wants cities and municipalities to work on separating their sewer water systems from their stormwater systems. He says the third key solution is treating wastewater effluent.
"There is room for reducing further [nutrient contamination] before the treated water enters in the rivers."
Clarification: An earlier version of this story referred to "algae blooms" in Lake Erie. These are really bacterial blooms (cyanobacteria) that look like algae. The copy has been clarified above.