House Republicans are overblowing the Environmental Protection Agency's decision to deny a mine permit in Alaska to demonstrate a political motive where none exists, a top Democrat said Thursday, invoking the Flint, Mich., water crisis to make her point.

"In that regard, I find it ironic that EPA has been condemned in recent weeks for doing too little to protect the water in Flint, Michigan, and at the same time they're being condemned by some of the same committees for doing too much to protect the water in Bristol Bay, Alaska," said Rep. Eddie Bernice Johnson of Texas, the House Science, Space and Technology Committee's top Democrat.

Johnson sought to downplay the efforts of the GOP at a hearing Thursday meant to demonstrate how the EPA colluded with activists to use its Clean Water Act authority to block the construction of a gold copper mine in Alaska near the world's largest fishery of sockeye salmon.

EPA's Pebble Mine decision "is not a political issue," she said. "It's about protecting a unique environmental resource."

It is "simply the wrong mine in the wrong place," Johnson said. "I also believe section 401(c) of the Clean Water Act has been used in the right way and the right place."

Rep. Lamar Smith, R-Texas, the chairman of the science committee, put EPA's regional director, Dennis McLerran, in the hot seat during the hearing, accusing him of overseeing "activist" employees who colluded with environmental groups to decide the mine's fate before its developer had a chance to apply for a permit.

The committee majority "is concerned that EPA did not rely on sound science in deciding to undertake a pre-emptive action to limit the Pebble Mine," according to the hearing charter.

Smith argued that the Pebble Mine case would set a harmful precedent for using the same pre-emptive action anywhere in the country.

Johnson said his assertion is false, and she submitted a report detailing the use of EPA's authority. Johnson and other Democrats defended McLerran, arguing that the EPA has the authority to use such pre-emptive action, which prior to the Pebble Mine had only been applied twice under former President Ronald Reagan.

"The law has not been widely used over the last few decades, nor should it be," she said. "It was designed to be used in special cases where potential development poses extreme adverse threat to U.S. waters."