A disappointing decision by the federal appeals court in Atlanta will legalize pollution in many American drinking water supplies, and we have the former Bush administration to thank for it.

The case goes back to 2002, when we sued, on behalf of the Florida Wildlife Federation, to get the South Florida Water Management District to stop pumping contaminated drainage canal water into Lake Okeechobee, one of the biggest drinking water sources in Florida, and the second biggest lake in the United States. For years, the district has been disposing of contaminated runoff from urban areas and industrial-scale sugar and vegetable farms by "backpumping" its untreated waters from drainage canals into Lake Okeechobee.

Since the Clean Water Act doesn’t allow anyone to add pollutants to lakes and rivers without a permit that limits pollutants to safe levels, we argued that the Water District needed a federal permit to pump filthy water into the public lake.

The enormity of the problem was evident: When the pump stations switch on, they flow at the rate of a medium-sized river and inject a plume of dark polluted water that reaches almost 10 miles into the lake. Toxic algae outbreaks in the lake in recent years have been transferred into rivers along with lake water, causing massive fish kills, covering the water with toxic green slime, and making it unsafe even to submerge an unprotected hand.

We had a major win in our case in 2007, when a federal court in Miami found that pumping canal water into the lake created a public health threat because it contaminated drinking water and triggered toxic algae outbreaks in the lake that kill wildlife and sicken people.

Instead of cleaning up the water, the water district appealed. U.S. Sugar Corp., the U.S. Army Corps of Engineers and the U.S. Environmental Protection Agency joined the case on the side of the polluters.

While the case was on appeal, the outgoing administration of President George Bush adopted a new rule squarely aimed at this case. It exempted from permitting all transfers of contaminated water from canals to lakes and between all other water bodies—regardless of whether the pumping contaminates drinking water and threatens public health.

On June 4, the appeals court in Atlanta ruled that the Water District did NOT need a permit under the Clean Water Act to pump dirty water into Lake Okeechobee. The judges said they had no choice but to accept the EPA’s Bush-era rule. Tellingly, one of the judges, Circuit Judge Ed Carnes, called the water pumped into Lake Okeechobee "a loathsome concoction of chemical contaminants," including nitrogen, phosphorous and ammonia.

The Bush administration rule doesn’t just affect Florida. It endangers drinking water reservoirs around the United States.

The U.S. sends tens of millions of dollars a year to Africa and developing countries to help them prevent drinking water contamination. It is ironic that, at the same time, the U.S. EPA is legalizing contamination of drinking water supplies here at home.