WASHINGTON -- The Environmental Protection Agency signed off Tuesday on making it easier to dump mountaintop mining waste near rivers and streams.

But the EPA said it did so because it secured additional safeguards.

The governors of Kentucky and Tennessee, as well as other lawmakers from those states, had urged EPA Administrator Stephen Johnson to block the rule -- which would rewrite a regulation enacted in 1983 that bars mining companies from dumping huge waste piles within 100 feet of temporary streams when it could diminish water quality and quantity.

Under a provision of the Surface Mining Control and Reclamation Act -- promulgated largely by the Interior Department -- the EPA must concur in writing to any mining regulations that could affect air and water quality.

The Bush administration needs the EPA's approval to make the rule final. The regulation has already cleared the White House, and officials with the Interior Department's Office of Surface Mining were expected to brief members of Congress later this week.

If the rule is made final 30 days before President-elect Barack Obama is sworn in, it would be difficult to change.

"Far from the 'giveaway' to the coal industry as it is characterized by some anti-coal extremists, the new rules actually tighten regulations relating to stream protections under the Buffer Zone Rule," said West Virginia Coal Association President Bill Raney. "This new rule is the product of four years of public hearings and environmental analysis by multiple federal agencies."

Environmentalists, however, saw little improvement in the rule Tuesday.

"They're not adding anything new," said Joan Mulhern, an attorney for Earthjustice. "They're just trying to confuse the public and make it sound like they're adding back in some environmental conditions."