U.S. EPA set new water-quality standards for surface coal mining in central Appalachia today that Administrator Lisa Jackson said would likely block mountaintop-removal projects from dumping wastes in streams.

The guidance sets the first-ever numeric standard for "conductivity," a measure of how well waters carry an electrical charge. The standard addresses levels of salt, sulfides and other pollutants in streams near surface coal mines. As salt levels rise in freshwater, so does conductivity.

To qualify for a Clean Water Act permit, mining companies must show their project would not cause the pollutant concentrations to climb past roughly five times the normal level, a limit the agency said would protect 95 percent of aquatic life.

There are "no or very few valley fills that are going to meet this standard," Jackson told reporters in a conference call. "Valley fill" refers to the practice of dumping waste from mines into nearby valleys. Mining operations have buried nearly 2,000 miles of Appalachian headwater streams, the agency said.

"We expect this guideline to change behaviors, to change actions," Jackson said. "Because if we keep doing what we have been doing, we'll continue to see degradation of water quality."

The standards were prompted by a growing body of research indicating surface mining is damaging Appalachia's environment and public health, Jackson said.

"The people of Appalachia shouldn't have to choose between a clean, healthy environment in which to raise their families and the jobs they need to support them," she said. "This is not about ending coal mining, it is about ending coal mining pollution."

EPA today also released two draft studies, one documenting the adverse effects on aquatic ecosystems of pollutant levels associated with high conductivity. Conductivity levels are on average 10 times higher downstream from mountaintop mines and valley fills than in unmined watersheds, the draft concludes.

The new regulations are effective immediately on an interim basis while EPA takes public comment and considers revisions. The regulations do not apply retroactively to existing Clean Water Act permits, but they will be applied to the nearly 80 permits that EPA last year held for "enhanced review," Jackson said.

Jackson said the new guidelines apply for now only to surface mines in Pennsylvania, Ohio, West Virginia, Virginia, Kentucky and Tennessee because that is where the data they are based on were gathered, but she said the science could eventually compel the agency to consider conductivity standards for waters surrounding underground mines, as well.

West Virginia's senior U.S. senator, Democrat Robert Byrd, praised EPA's action. "I am pleased that EPA Administrator Jackson took our concerns about the need to provide clarity very seriously and has responded with these guidelines," he said in a statement. "Today's announcement will hopefully now have everyone reading off the same page."

But industry groups blasted the new regulations, calling them job-killers that would further depress one of the country's poorest regions. According to the National Mining Association, Appalachian surface mining employs more than 26,000 workers and produces 145 million tons of coal annually, about 11 percent of total U.S. production.

"EPA continues to point to 'new science' that has been found to be both flawed and limited in its findings and application as justification for today's announcement," the trade group said in a statement. "We urge EPA to give greater thought to the impact on jobs, affordable electricity and U.S. steel production caused by further permitting delays and roadblocks resulting from the agency's ill-considered policy decisions."

Environmental groups called the standards a major and much-needed crackdown on coal-mining pollution.

"The new policy represents the most significant administrative action ever taken to address mountaintop-removal coal mining," said Sierra Club Executive Director Michael Brune. "Today's announcement reaffirms the Obama administration's commitment to science and to environmental justice for the communities and natural areas of Appalachia."

Click here to read EPA's draft assessment of conductivity standards.

Click here to read EPA's study of the affects of surface mining on aquatic ecosystems.