The end of September brought a grim reminder to Toledo residents and others living around Lake Erie: more than 700 square miles of the lake’s surface was covered with algae. For many, it brought renewed fears about the drinking water supply. In 2014, Toledo’s water supply was shut off for three days because cyanobacteria in the algae blooms produced dangerous levels of potentially liver-damaging toxins.
Lake Erie supplies drinking water for about 3 million people in total. Officials say toxin levels near the various water intakes are currently low, despite the presence of algae. But as one of my colleagues used to say, “Appearances are everything,” and the sight of green slime on the water’s surface is having other consequences. For one, it’s driving away tourism. The vice president of the Lake Erie Charter Boat Association, quoted in this New York Times article, says “An awful lot of money may go someplace else other than Ohio if we continue having these issues in the lake.”
And it’s likely they will continue—the algae blooms have been increasing in size for the last couple of decades, fueled by high levels of phosphorus in agricultural runoff. The Maumee River, which flows into Lake Erie, carries much of the sediment and nutrients from farmland. A week ago, it, too, appeared bright green.
This article, published in Stormwater shortly after the Toledo drinking water crisis in 2014, describes the multinational efforts to monitor the lakes under the Great Lakes Water Quality Agreement, as well as work by the Ohio Lake Erie Commission and others. The groups address concerns such as nutrient loading, sediment, oxygen depletion, invasive species, and various contaminants.