DENVER -- Gov. Bill Ritter is appealing to Interior Secretary Dirk Kempthorne in dealing with water accumulating in a Leadville tunnel.

A collapse inside the Leadville Mine Drainage Tunnel first detected in 1995 has allowed water to back up in hundreds of mine shafts. Local officials fear there could be a catastrophic blowout of the blockage, flooding parts of Leadville and killing scores of residents.

The area is part of an Environmental Protection Agency Superfund site.

The EPA has a plan to pump water from the tunnel to be treated by the Bureau of Reclamation, which has agreed to treat more water to reduce the buildup.

But Ritter told Kempthorne in a letter Sunday that the state wants the bureau to agree to treat the mine discharge water in perpetuity.

Bureau spokesman Peter Soeth said agency officials had not seen the letter and could not comment.