Five years after half a million Toledo-area residents were told not to drink or touch their tap water for two days, the same thick green sludge responsible for the 2014 water crisis has now spread across 600 square miles of western Lake Erie.
And it’s expected to grow during peak HAB (Harmful Algal Bloom) season: mid-summer through mid-fall, when temperatures climb and spring rains have washed nutrient runoff from farms into the lake.
NOAA (National Oceanic and Atmospheric Administration) forecasters predict this year’s bloom will be one of the worst in recent years. Researchers like Ed Verhamme, a project engineer at LimnoTech in Ann Arbor, have launched an “all-out assault” on monitoring the bloom, trying to figure out if efforts to reduce pollution are working.
“The bloom is definitely large enough to effect recreational use of the lake, swimming; and it can definitely complicate [drinking water] treatement,” Verhamme says. “There are algal toxins that are above water standards right now. So water treatment plants are having to spend extra money to add chemicals to remove the bloom. So it’s a very ugly, green bloom out there.”
Verhamme and dozens of other researchers were on the lake last week, trying to get an “on-the-water look at the size of this,” he says.
“It’s just remarkable. We had folks that left from Windsor, on the Canadian side, and they saw the bloom. We saw folks that left ports in Monroe, very heavy bloom there. We left from the Toledo area: green water there. And folks over left from Catawba over by Sandusky, and again, lots of green water there as well.”
Since the 2014 crisis, water treatment plants have made major upgrades and should be able to prevent another contamination, Verhamme says. “Every water treatment plant has a comprehensive plan that covers how they’re going to prepare, and treat, water that has algal toxins in it. So there’s not much fear of a repeat of 2014… All the plants are well-prepared and are monitoring the bloom closely.”
Both the US and Canada have committed to some “pretty substantial reductions in nutrients” to reduce the size of the bloom, he says, with “hundreds of millions of dollars” in tourism and industry on the line.
This year’s bloom would have been worse, Verhamme says, but for a wet fall and spring that prevented farmers from planting as many crops. “As part of that not-planting, they didn’t fertilize…so if that were to have happened, scientists estimate an additional 30% more nutrients would have run off into the lake, in addition to what was already running off from previous years’ fertilizer applications.”
But Verhamme says one thing’s for sure: this year’s bloom will continue to grow.