Workers scoop up tar-like residue floating in the inland waterways at Perdido Pass in Orange Beach, Alabama, last week. After hours of drifting, much of the usable material in crude oil evaporates. By Maurice Cohn Band, The Miami Herald, via AP

By Alan Levin, USA TODAY Oil giant BP is facing a huge new challenge in disposing of the millions of gallons of potentially toxic oil sludge its crews are collecting from the Gulf of Mexico, according to industry experts and veterans of past spills. Crews so far have skimmed and sucked up 21.1 million gallons of oil mixed with water, according to the Deepwater Horizon Unified Command. Because the out-of-control well may continue spewing for months, that total almost certainly will surge. BP’s plan for handling the gooey mess, written in conjunction with the Coast Guard, the Environmental Protection Agency and Louisiana officials, calls for reclaiming or recycling as much as possible. Some experts said that approach is the best option for the environment, but it has not worked in previous spills. It is not profitable to refine sludge that has mixed with water and seagoing debris because it can actually ruin refineries, they said. “It has no longer got any economic value. It has to be disposed of as garbage,” said Marc Jones, a former Navy officer who helped oversee numerous oil spill cleanups, including the 1989 Exxon Valdez in Alaska. “The stuff that got recovered from the Exxon Valdez was just a nightmare.” So far, BP has released little information about what it has done with the skimmed oil. Mike Condon, BP’s environmental division chief, said Wednesday that at least four barges filled with the waste had been shipped to disposal facilities in Texas and Alabama. “We’ve had some challenges finding the facilities that can handle it,” Condon said. He said he was told that at least some of the recovered oil has been refined but was unsure of details. Disposing of skimmed oil is not only difficult and expensive, but simply collecting the material has often slowed down cleanup efforts in previous spills, the experts said. Merv Fingas, a former top scientist at Environment Canada who has studied oil spills for decades, said finding storage for skimmed oil was the “prime bottleneck” in cleanup efforts. Jones said he recalled observing a skimming boat in the oil-saturated waters immediately after Exxon Valdez fill its holding tank after only 15 minutes. “It took us 2½ days to get offloaded,” Jones said. There weren’t enough tanks and barges to handle the waste. “The one thing that you can always count on being a major headache is interim storage.” …

BP’s next challenge: Disposal of tainted sludge