40 CFR 63.5710 - How do I demonstrate compliance using emissions averaging?
(a) Compliance using the emissions averaging option is demonstrated on a 12-month rolling-average basis and is determined at the end of every month (12 times per year). The first 12-month rolling-average period begins on the compliance date specified in § 63.5695.
(b) At the end of the twelfth month after your compliance date and at the end of every subsequent month, use equation 1 of this section to demonstrate that the organic HAP emissions from those operations included in the average do not exceed the emission limit in § 63.5698 calculated for the same 12-month period. (Include terms in equation 1 of § 63.5698 and equation 1 of this section for only those operations and materials included in the average.)
(e) If the organic HAP emissions, as calculated in paragraph (b) of this section, are less than the organic HAP limit calculated in § 63.5698(b) for the same 12-month period, then you are in compliance with the emission limit in § 63.5698 for those operations and materials included in the average.