(a) You must conduct subsequent performance tests to demonstrate compliance with all applicable PM or total metal HAP, VOHAP, and TEA emissions limitations in Sec. 63.7690 for your iron and steel foundry no less frequently than every 5 years and each time you elect to change an operating limit or to comply with a different alternative emissions limit, if applicable. The requirement to conduct performance tests every 5 years does not apply to an emissions source for which a continuous emissions monitoring system (CEMS) is used to demonstrate continuous compliance.
(b) You must conduct subsequent performance tests to demonstrate compliance with the opacity limit in Sec. 63.7690(a)(7) for your iron and steel foundry no less frequently than once every 6 months. [69 FR 21923, Apr. 22, 2004, as amended at 73 FR 7219, Feb. 7, 2008]