The lawsuit filed Thursday contends the proposed expansion and paving at the airport between Sparta and Cookeville would destroy a wetlands area that empties into the Falling Water River.
Jim Murphy, water resources counsel for the National Wildlife Federation, said U.S. District Judge Aleta Trauger set a May 9 hearing.
William James, chief of the eastern regulatory section of the Corps in Nashville, declined comment.
''We have not seen the lawsuit,'' he said.
An airport official did not return telephone messages seeking comment.
Environmental groups contend the region is home to wildlife, waterfalls, scenic hiking, fishing and hunting, and needs to be protected.
Murphy said the Corps and Environmental Protection Agency were failing to enforce the Clean Water Act based on an improper interpretation of a 2001 U.S. Supreme Court decision. He said the Bush administration has used that decision to skirt Clean Water Act safeguards.
Murphy said tests showed dye flowed from the wetlands area, at some points underground at the existing airport, and ''popped up at a spring that emptied into the Falling Water River.''
''If wetlands like these are not protected under the Clean Water Act, it could signal open season for the federally unregulated pollution and destruction of Tennessee's waters,'' he said.
John Harwood, program chairman of the Upper Cumberland Group of the Sierra Club, said the ''wetland area presents for me and other residents of the Upper Cumberland area the rare experience of viewing a high quality marsh ringed by a swamp.''
''Rather than being turned into pavement, with proper protection this wetland area could instead serve as a recreational and educational feature for local residents and visitors to the airport,'' he said.
