On Thursday, a DC federal judge struck down a controversial rule that decreased protections for waterways near mountaintop removal mining operations. The 2008 stream buffer zone rule, which removed protections for waterways, was issued during the final weeks of the Bush administration, Law360 reports.

US District Judge Barbara J. Rothstein found that the federal government violated the Endangered Species Act by ignoring evidence that the stream buffer zone rule threatened critical habitats. The National Parks Conservation Association and other conservation groups reopened the litigation against the Interior Department in January, accusing the government of failing to fulfill an out-of-court settlement to address the Bush-era rule.

Earthjustice attorney Neil Gormley, who represents the conservation groups, said the judge’s decision will provide water protections for states like West Virginia, where a recent chemical spill polluted the water supply of 300,000 residents, placing 9 counties in a state of emergency.

“This decision restores longstanding stream protections and finally puts an end to the Bush administration’s attempt to let mining companies dump toxic waste into our waterways,” Gormley said in a statement. “We’re glad to see it struck from the books and gone as the law of the land. Good riddance to a harmful midnight rule that hurts communities and waterways.”

Before the Bush administration’s rule, a stream buffer zone existed to protect waterways from mountaintop removal mining pollution. The buffer zone protected critical habitats from mining activities and prevented dumping around waterways. According to Earthjustice, “Mountaintop removal mining has buried an estimated 2,400 miles of Appalachian streams and polluted many more miles of waters.”

Mountaintop coal removal involves blowing up mountaintops to access coal seams below. According to the Natural Resources Defense Council, mining companies are “Filling local rivers and streams with blasted debris, polluting drinking water with toxic waste and sacrificing the safety and sanctity of countless communities.”

The original stream buffer zone rule was created in 1983 to restrict the dumping of waste from mining operations within 100 feet of a stream, “allowing such activities only upon finding that they ‘will not adversely affect the water quantity or quality or other environmental resources of the stream,’” according to Southern Environmental Law Center.

The Bush rule allowed dumping when alternative options were “not ‘reasonably’ possible,” including when the cost of pursuing an alternative to dumping cost a company more money than dumping the debris. A spokesman from the National Mining Association told Law360 that the organization is considering its legal options now that the Bush rule has been struck down.

“We’re obviously disappointed and examining the ruling closely to see what if any further action may be appropriate,” he said. Judge Rothstein rejected the National Mining Association’s arguments that the Bush rule be remanded to the federal Office of Surface Mining rather than be voided altogether.

Alisha is a writer and researcher with Ring of Fire. You can follow her on Twitter @childoftheearth.