On December 17, 18, 2003, and March 3, 2004, Von Roll conducted comprehensive perfomance tests as the hazardous waste combustor MACT requires, and the company exceeded the cadmium/lead emission standard (combined emissions) for exisiting hazardous waste incinerators. On March 30, 2004, EPA approved Von Roll's March 18, 2004, request for interim operating requirements including a maximum lead/cadmium feed rate of 10.07 lbs/hr, a feed rate at which Von Roll had demonstrated compliance with the lead/cadmium standard on March 15, 2004. (Von Roll's average lead/cadmium feed rate since 1993 is approximately 10 lbs/hr.) On April 20, 21, and 22, 2004, Von Roll conducted a comprehensive performance tests under three different operating conditions, and demonstrated compliance with the lead/cadmium standard under all three conditions. Von Roll audited the waste profiles for the wastes that it receives, and corrected lead concentration data errors in 25 of the 7908 waste profiles. On June 24, 2004, Von Roll reported to U.S. EPA the results of its audit. Von Roll acknowledged that it undercalculated the lead/cadmium feed rate during the December 2003 and March 2004 tests.