When you think about pollution from coal-burning power plants, you probably picture smokestacks spewing out dirty air. What most people don’t realize is that coal plants are a huge water polluter—leaking more toxic pollution into America’s waters than any other U.S. industry.

We’ve filed two cases recently—one in Kentucky and one in Florida—to stop these toxic discharges into the Ohio River and the Apalachicola River.

Coal ash is the toxic waste left over after the coal gets burned to generate electricity. Despite being chock-full of dangerous pollutants like mercury, arsenic (a known carcinogen), lead, selenium and cadmium, utility corporations store it all over the country in massive, unlined pits. These pits leak pollution into groundwater and streams—water that nearby communities often rely on for drinking supplies. These pollutants also build up in ecosystems, and most are dangerous even in very small amounts.

While the Clean Water Act does protect waterways from pollution, there are no federal safeguards specific to coal ash pollution. Household garbage, in fact, is better regulated than toxic coal ash. Coal ash has already contaminated more than 200 lakes, streams, rivers and drinking water aquifers across the country.

In Kentucky, time-lapse photography from a camera strapped to a tree captured a year’s worth of images proving that dangerous coal ash wastewater from Louisville Gas & Electric’s Mill Creek Generating Station has been pouring unabated into the Ohio River. In May, The Sierra Club and Earthjustice filed a lawsuit in federal court against the utility company. 

The photographic evidence, along with Google Earth satellite images from 1993 to the present, detail how LG&E is also violating the Clean Water Act. Under its existing permit, LG&E may at most only “occasionally” discharge into the river. LG&E’s own sampling of its Mill Creek coal ash dump found mercury levels in 2007 that were 20 times Kentucky’s human health standards.

The company’s coal ash waste impoundment sits on the Ohio River about 500 feet from a large residential neighborhood and 1,000 feet from a middle school. Despite this close proximity, Kentucky law does not require LG&E to test its coal ash wastewater for specific toxic pollutants such as mercury. The Environmental Protection Agency previously classified the coal ash pond as being "high hazard," meaning a failure of the ash pond dam would probably cause a loss of human life and significant environmental damage.

Down in Florida, another coal ash impoundment is polluting the Apalachicola River. This is a very special river. On June 6, U.S. Interior Secretary Sally Jewell and National Park Service Director Jonathan Jarvis announced a new, 106-mile-long national recreation trail called the Apalachicola Blueway.

“The Apalachicola River flows through one of the nation’s richest hotspots of biodiversity and is bordered by large tracts of pristine, undeveloped land, which are home to many threatened and rare species of plants and animals,” the government’s National Trails Day press release said. “The river flows through the heart of Old Florida, a tapestry of wild landscapes and vanishing cultures.  It is a rare gem in the Florida Panhandle.”

Just two days before the government’s national trails announcement, we filed a lawsuit under the Clean Water Act to protect this rare gem from pollution leaking out of unlined coal ash pits at Gulf Power Company’s Scholz Generating Plant near Sneads, Florida.

The coal ash pits are contaminating the water with arsenic, cadmium, and chromium—all well-known carcinogens—as well as aluminum, barium, beryllium, copper, lead, nickel, zinc, selenium and mercury. One test, in June 2013, found that arsenic levels coming out of the unlined pits were 300 times the amount considered safe for drinking water.

Gulf Power has a federal Clean Water Act permit, which allows it to discharge treated coal ash water and chlorinated condensing water directly into the Apalachicola through an outfall. But contamination is leaking at other points on the site and not receiving proper treatment, and those discharges are not covered by the permit. The toxic heavy metal leaks—and the company’s decision not to report them—violate Gulf Power’s federal permit requirements under the Clean Water Act.

Earthjustice attorneys Alisa Coe and Bradley Marshall filed our Clean Water Act suit in U.S. District Court in Tallahassee, Fl. on behalf of the Southern Alliance for Clean Energy, Waterkeeper Alliance and Apalachicola Riverkeeper.

Gulf Power is a subsidiary of the $38-billion Southern Company, and the plant along the river is 61 years old. The company decided to close it next year rather than make needed environmental upgrades. We want to make sure that when Gulf Power shutters the plant, the leaking mess does not become the taxpayers’ problem. 

The coal ash disaster that hit North Carolina in February remains very much on our minds. A stormwater pipe below a huge Duke Energy coal ash pit failed, spilling 140,000 tons of toxic pollution into the Dan River. It now coats the bottom of the Dan River for 70 miles downstream, and the full health and economic impacts of this spill are still adding up.

The Sierra Club and Earthjustice are also involved in a separate legal agreement, along with nine other public health and environmental organizations and a Native American tribe, compelling the EPA to finalize new federal regulations dealing with the handling and disposal of coal ash waste by December 19.