CHARLESTON, W.Va. -- National and state citizen groups are threatening to sue the U.S. Environmental Protection Agency for not stepping in to force West Virginia regulators to clean up hundreds of polluted streams.On Friday, lawyers for the Sierra Club, the West Virginia Highlands Conservancy and the Ohio Valley Environmental Coalition sent their formal notice of intent to sue to EPA headquarters in Washington.Technically, the threatened suit focuses on EPA's failure to act within the required 30 days to approve or reject the state Department of Environmental Protection's list of polluted streams that need cleaned up.But the suit brings to light a simmering controversy over DEP not including hundreds of streams on that list, based largely on a coal industry-backed bill passed during last year's legislative session.The bill, signed by Gov. Earl Ray Tomblin, ordered DEP to abandon its existing methods of measuring stream health and come up with a new set of rules to define when streams are considered biologically impaired. DEP has yet to write those rules, and agency officials declined to add to last year's cleanup list hundreds of streams that might otherwise have been included."We need someone to call a stream polluted when it is, and if the West Virginia DEP won't do it, then the EPA must," said Jim Sconyers of the state Sierra Club chapter.At issue in the potential lawsuit is the DEP's latest list of "impaired" streams. Federal law requires states to periodically publish such lists, and then to develop plans to clean up pollution in the contaminated waterways.Under the law, if states don't comply then EPA is supposed to step in, and EPA also is charged with reviewing state stream lists and ensuring local regulators are doing the job properly.In West Virginia, the DEP has for years used a measure called the West Virginia Stream Condition Index, or WVSCI, to grade if waterways are "biologically impaired." EPA has been pushing the state to use another test that it believes is more accurate. State officials and the coal industry, though, oppose the EPA method.Last year, lawmakers passed SB562, which ordered DEP to write new rules for "evaluating the holistic health of the aquatic ecosystem," a move that agency Secretary Randy Huffman has said he supports."I'm glad they did that," Huffman said. "I supported that."Top DEP officials opposed EPA's version of a biological impairment test, and Huffman said he also believed that the state's WVSCI should also not be the only measure used in making such determinations. And while state officials come up with a new method and write rules to govern it, DEP decided not to make any new impaired stream listings based on either of the current tests.When environmental groups examined state records and data, they found that DEP's latest list did not include 173 streams that would have been included if the state's old formula had been used to measure their biological health. They also found that more than 540 streams weren't listed that would have been if EPA's method had been used.In a report on its listing decisions, DEP said that, in response to SB562, it was "not adding new biological impairments" to the list until the new rules are written. When the new rules become effective, DEP cautioned, "delisting ... may occur if the application of the methodology demonstrates a non-impaired condition."The DEP's latest list -- without those streams -- was submitted to EPA for federal review on Dec. 21. Under the law, EPA had 30 days to either approve or reject the list. EPA did neither. Instead, federal officials asked to schedule a conference call with EPA staffers about the matter."That response is not only legally deficient; it also reinforces the state's recalcitrance," wrote Appalachian Mountain Advocates lawyer Joe Lovett, who filed the formal lawsuit notice with EPA on behalf of citizen groups. "EPA's passivity towards WVDEP's refusal to enforce the Clean Water Act not only harms our environment, but weakens the rule of law in our region."Reach Ken Ward Jr. at firstname.lastname@example.org or 304-348-1702.