The New Source Performance Standards (NSPS) for Steel Plants: Electric Arc Furnaces and Argon Oxygen Decarburization Vessels that are included in both Subpart AA and AAa regulate emissions of particulate matter from electric arc furnaces constructed after October 21, 1974, and on or before August 17, 1983, and the new source performance standards for electric arc furnaces constructed after August 17, 1983.
Additional information regarding the applicability of these rules to the foundry industry is provided in the following links.