You are subject to this subpart if you own or operate an engine test cell/stand that is located at a major source of HAP emissions.
(a) An engine test cell/stand is any apparatus used for testing uninstalled stationary or uninstalled mobile (motive) engines.
(b) An uninstalled engine is an engine that is not installed in, or an integrated part of, the final product.
(c) A major source of HAP emissions is a plant site that emits or has the potential to emit any single HAP at a rate of 10 tons (9.07 megagrams) or more per year or any combination of HAP at a rate of 25 tons (22.68 megagrams) or more per year.