Cleanup of munitions, waste could take 300 years or more Tribune Staff and Wire Reports     WASHINGTON -- Removing unexploded munitions and hazardous waste found so far on 15 million acres of shutdown U.S. military ranges could take more than 300 years, congressional auditors say.     Seventeen Utah sites were among those sites potentially contaminated. Among those were areas identified as the Wendover Bombing and Gun Range, the Carrington Island Precision Bomb Range, the Wendover Special Weapons Bombing Range, the Dugway South Triangle and the Skull Valley Sheep Burial Site. The latter apparently refers to the area where about 6,000 sheep were buried that were killed by a deadly nerve agent that drifted off the Army's Dugway Proving Ground in 1968.     In a report to Congress, the General Accounting Office said the Defense Department has yet to assess three-fifths of the 2,307 potentially contaminated sites identified as of September 2002 and has finished cleaning up only 1 percent of them. Some of the areas have been redeveloped for homes and parks.     The report, obtained by The Associated Press before its release, said the Pentagon "does not yet have a complete and viable plan" to guide its remaining cleanups. Assessments of the sites not yet examined in detail for possible explosive hazards, chemical warfare material and chronic health and environmental hazards won't be completed until 2012, the GAO said.     The department's latest estimate for the cleanups is anywhere from $8 billion to $35 billion. That's an increase from its previous estimate, little more than a year ago, of up to $20 billion.     At the current rate of annual spending -- $106 million on average during the Bush administration -- the cleanup "could take from 75 to 330 years to complete," the auditors said.     Defense officials say they have spent $25 billion over the past two decades on environmental restoration at more than 29,500 military sites, including ordnance testing and training ranges.     But the officials say they don't have a breakdown on how much of that was devoted to munitions cleanups. In recent years, about 5 percent of the cleanup budget has been devoted to sites once associated with munitions.