On May 7 and 8, eight cases were filed in the U.S. Court of Appeals for the District of Columbia Circuit to review the Environmental Protection Agency (EPA) nonhazardous secondary materials rule. Three other cases were previously filed, and ten of these 11 cases will be compiled into the petition by the National Association of Clean Water Agencies. The rule, which took effect April 8, clarifies what materials may be considered fuels rather than solid waste when burned in boilers or solid waste incinerators.