August 7, 2015
Out on Lake Erie, Sandy Bihn of Lake Erie Waterkeeper is holding up a glass of lake water with little green blobs floating in it.
“It’s not nearly as dense as it was last year when we were out here,” Bihn says. “The bloom has moved further east which is good for Toledo.”
The bloom Bihn is talking about is a cyanobacteria bloom that’s spreading in Lake Erie right now—one which scientists are predicting could become the second-worst on record. And people in charge of Toledo’s water system are on alert. A year ago, a similar bloom shut down Toledo’s drinking water supply.
The bacteria produce a toxin called microcystin. Officials say microcystin can cause skin irritation and could affect the liver and nervous systems if it is consumed in large amounts. Toledo officials have recently detected low levels of microcystin in untreated water from Lake Erie. But they say, right now, their treatment system is removing the toxin and city water is safe to drink.
“We’re light years ahead of where we were before in terms of water treatment,” says Joel Mazur, the Commissioner of Field Operations with the water department. He says they’ve stepped up monitoring and added more treatment steps to take out the toxin. And they've also put in an advanced warning system after last year’s crisis. Now, there’s a monitor in the intake crib—a structure on the lake which is the source for Toledo’s water supply.
“Now that we’re detecting microcystin in the water, we have crews that actually come out and they're taking samples so we can have daily monitoring.”
The city has a water quality dashboard on its website, which allows citizens to check the status of their drinking water. Right now, the water is at the “watch” level, meaning the city has detected microcystin in the lake but not in tap water.
In June, Michigan Governor Rick Snyder, Ohio Governor John Kasich and Ontario Premier Kathleen Wynne pledged to cut phosphorus pollution getting into Lake Erie by 40 percent over the next 10 years. Phosphorus, a nutrient key to cyanobacteria growth, gets into the lake from farm fertilizer, wastewater from cities and other sources.
Sandy Bihn of Lake Erie Waterkeeper says we need better monitoring of all these sources.
“We know that [agriculture] is a huge contributor. I mean, we know what the categories are. We don’t know the specific locations and amounts. That’s what we’re missing.”
She says officials need to track exactly how much phosphorus is coming from each source. And farmers are calling for a similar approach.
“I’m tired of hearing hypotheticals on where things are coming from,” says Bill Myers, president of the Lucas County, Ohio Farm Bureau. “We need to know for sure what areas are contributing and target the highest levels with the quickest response to get the hugest decrease as fast as we can.”
This spring, Ohio passed a law that bans farmers from spreading fertilizer on frozen or rain-soaked fields. It’s intended to cut back on phosphorus that runs off those fields.
In the meantime, scientists are trying to solve a mystery about these toxic blooms.
“One of the really interesting findings so far has been that, as we track these blooms through the season, the bloom develops and it progresses and it’s toxic," says Greg Dick, an associate professor of earth and environmental sciences at the University of Michigan. “But then towards the end of the summer, we still have a really strong bloom with very dense cyanobacteria, but the toxicity of that bloom changes. And in particular, the toxicity of the bloom drops off.”
He says they could find some clues in the DNA of these bacteria. Only some strains seem to have the gene to produce the toxin.