(a) The provisions of this subpart and of subpart A of this part apply to control of regulated material emissions from surge control vessels, bottoms receivers, and other storage vessels where a referencing subpart references the use of this subpart for such emissions control.

(b) If a physical or process change is made that causes a storage vessel to fall outside the criteria in the referencing subpart that required the storage vessel to control emissions of regulated material, the owner or operator may elect to no longer comply with the provisions of this subpart. Instead, the owner or operator shall comply with any applicable provisions of the referencing subpart.