At a congressional hearing, Sen. Barbara Boxer (D-Calif.) said the Environmental Protection Agency had designated as confidential the details of about 140 Superfund sites where toxic exposure remained uncontrolled. The secret data included information about how much money and time it would take to clean up the dangerous sites, including one site where the EPA predicted it would take 26 years to close off access to toxics. This isn't a question of left or right," Boxer said, waving a document marked "Privileged" by EPA officials to prevent its release to the public. "This is a question of right and wrong." The Superfund program was created almost three decades ago in response to environmental disasters such as Love Canal, a neighborhood in Niagara Falls, N.Y., where chemical contamination forced the removal of 800 families and led to $200 million in remediation costs. Those sites are areas where the public still faces some possible exposure to toxic substances -- such as a building near buried radioactive waste that was not surrounded by a fence. A skateboard park built over the site, however, was protected by a layer of dirt. One Republican-sponsored bill moving through Congress would limit data available on toxic substances released into communities, and the U.S. Army Corps of Engineers has blocked information on flooding dangers in Florida.