40 CFR § 63.9635
How do I demonstrate continuous compliance with the work practice standards that apply to me?
June 9, 2020
(a) You must demonstrate continuous compliance with the work practice standard requirements in §63.9591 by operating in accordance with your fugitive dust emissions control plan at all times.
(b) You must maintain a current copy of the fugitive dust emissions control plan required in §63.9591 onsite and it must be available for inspection upon request. You must keep the plan for the life of the affected source or until the affected source is no longer subject to the requirements of this subpart.