President Bush headed to Pennsylvania on Friday to sign into a law a five-year plan to revitalize brownfield sites around the country. Under the plan, which was approved by Congress last month, the feds will allocate up to $250 million per year to states, local governments, and Native American tribes, with the goal of cleaning up some 450,000 of the polluted industrial sites. The sites will be converted into public, residential, or commercial areas. After the U.S. EPA certifies the areas as clean, developers and new owners of the sites will have liability protection, shielding them from having to pay for removing any remaining contamination in the future.