Dairy Farm Pollution Fuels Lake Erie’s Toxic Algae
As summer approaches, so do the toxic algal blooms that plague Lake Erie every year, killing fish and making the water too dangerous to swim in.
Phosphorous runoff from farms is the key culprit, and most of it comes from synthetic fertilizers applied to the region’s corn and soybean fields. But manure from concentrated animal feeding operations (or CAFOs) in Ohio and Michigan also contributes to the noxious blooms.
The 140 CAFOs in the Lake Erie watershed produce an estimated 630 million gallons of animal waste a year. Manure is often stored in large storage “lagoons,” but some of it inevitably seeps into groundwater and nearby waterways, triggering the blooms of blue-green algae, or cyanobacteria.
The blooms are toxic to fish, livestock and people. At high doses, cyanobacteria can cause liver failure. After even a brief exposure, the toxins can cause skin rashes, eye irritation and breathing problems.
In July 2015, for example, a fisherman named Todd Steele had to be hospitalized for treatment of the hives he contracted just from handling fish from Lake Erie. It prevented him from fishing again the rest of the year.
Last year, the toxic algae in the lake rivaled the 2011 algae bloom, which was three times larger than any previously observed in the area. Photos taken by NASA of Lake Erie and Lake St. Clair last summer showed neon green swirls of the toxic blooms.
Dairy cows defecate about 80 pounds a day, and the resulting manure is largely unregulated. State and federal agencies only regulate pollution coming from “large CAFOs,” which are defined as having at least 700 dairy cows on one farm, and only when a CAFO “proposes to discharge” directly into a river or lake.
The average size of a dairy farm in Michigan is only 176 cows, but that’s enough to produce 14,000 pounds of manure daily. So most CAFO operators are largely exempt from environmental regulation – the federal Clean Water Act in particular.
Making matters worse, Congress has proposed to cut the U.S. Department of Agriculture conservation programs that reward dairy producers and other farmers when they take steps to reduce pollution.
Don’t be surprised if Lake Erie becomes a green toxic stew once again this year.