Toxic algae is the byproduct of the same types of pollution that causes dead zones in the Gulf of Mexico and the Chesapeake Bay — phosphorous and nitrogen from livestock manure and chemicals sprayed on crops such as corn that spills from farms into assorted waterways during moderate to heavy rains.
Urban sewage overflows that send millions of gallons of stormwater mixed with raw human waste during rains also contributes to the problem, even though such point-source pollution, unlike most non-point-source farm pollution, is heavily regulated by the federal government, environmentalists say.
The effects of polluted runoff is made worse by the changing climate, said Hans Paerl, professor of marine and environmental sciences at the University of North Carolina. “Global warming and intensification of major storms and droughts play major roles in the spread of toxic blue-green algal blooms worldwide.”
At least one drinking-water provider, Des Moines Water Works, is struggling to clean nitrates from water it supplies to a half-million customers as a result of polluted runoff from farms.
Nitrates recently spiked to twice the level the Environmental Protection Agency allows, forcing the utility to pass the million-dollar cost of cleaning water drawn from the Raccoon and Des Moines rivers to ratepayers.
The report, “Toxic Algae: Coming Soon to a Lake Near You?”, was released Tuesday by the National Wildlife Federation’s Great Lakes Regional Center, an environmental nonprofit group, and Resource Media, a nonprofit public relations organization, to raise national awareness of the problem.
It describes a growing toxic danger that threatens human health and has claimed the life of at least one person, more than 20 pets since 2001 and a multitude of marine life.
The report follows a federal court’s ruling ordering the EPA to fulfill its obligation under the Clean Water Act and draw up a plan to limit the flow of pollution into the Mississippi River, which feeds into the gulf.
In a Sept. 20 decision written by Judge Jay C. Zainey, the U.S. District Court for Eastern Louisiana sided with environmental groups that challenged the EPA’s “hands-off approach” to managing pollution.
An EPA attempt to dismiss the suit was denied. The court was not persuaded by the agency’s argument that it was leaving it to states to manage pollution, with EPA’s help, because it had no jurisdiction to compel a cleanup.
Zainey gave the EPA six months to at least begin to develop a plan. A spokesman for the Department of Justice, which represented the federal government in the suit, said only that its lawyers were reviewing the decision and had not decided its next step.
The suit was filed by several nonprofit environmental groups, including the Environmental Law and Policy Center, Minnesota Center for the Environment, Iowa Environmental Council in Des Moines and the Natural Resources Defense Council, among others.
“We are gratified that EPA cannot duck this important decision, and hope [it] takes quick and decisive action to control widespread nitrogen and phosphorus pollution in the Mississippi River,” said Kris Sigford, the water quality director at Minnesota Center for the Environment.
“Lake recreation is a big business in Iowa—generating $1.2 billion in annual spending and supporting 14,000 jobs,” Susan Heathcote, the water program director of the Iowa Environmental Council in Des Moines, said in a statement.
“Yet Iowa’s lakes have among the highest nitrogen and phosphorus levels in the world, and consequences of this problem, including algae blooms and poor water clarity, have already landed 79 of the state’s top recreational lakes on Iowa’s impaired waters list.”
The algae report also calls on federal officials to do more to limit water pollution. It advises federal and state officials to restore tainted water, pass a farm bill that calls for less runoff and healthy soil, and pay for more research into algae blooms and hypoxia, the oxygen-depleted water conditions that causes fish-killing dead zones.
Algae turns water green when rain is followed by drought. Bacteria from algae thrive when water levels fall in lakes, reservoirs and ponds, taking advantage of the low flow and low volume.
Cyanobacteria, often called blue-green algae, can produce nerve toxins and toxic chemicals that attack human skin. “In some cases,” the report said, some toxins “can cause asthma-like symptoms, severe vomiting, diarrhea or irritated skin or eyes.” Children are most at risk, it said.
The only known human fatality linked to algae occurred in Dane County, Wis., after a 17-year-old dived and splashed in a scum-covered pond at a county golf course. That death in 2002 was the first in the nation caused by toxic algae.
Two years ago, Sen. James M. Inhofe (R-Okla.) fell ill after swimming in an algae-covered lake near his house in Oklahoma.
Over the past summer, New York waters had the most reports of toxic algae infestation with 50, followed by Kansas with 18 and Washington with 12. In all, there were 147 reports in Iowa, Oregon, Ohio, Kentucky, Florida and California, among other states.
Grand Lake St. Mary’s in Ohio has spent $8 million since 2009 removing green slime that has cropped up May through October. In southeast Florida, the St. Lucie River and Indian River Lagoon were choked with algae, prompting the state Department of Health to warn residents to avoid it.
A massive algal bloom in southwest Florida killed a record 241 of Florida endangered manatees where they spend winter, according to a count by the states Fish and Wildlife Institute. There are only about 5,000 manatees in the wild.