Slotted Guidepoles at Certain Petroleum and Organic Liquid Storage Vessels

This action provides express notice that slotted guidepoles at certain petroleum storage vessels and tanks may not comply with regulatory requirements. Slotted guidepoles are relatively simple devices for sampling the contents of a floating roof storage tank. Unless they are controlled, the slots, hollow core and the space between the guidepole and the tank's roof are observable emission pathways that violate the ``no visible gap'' prohibition in the Standards of Performance for Storage Vessels for Petroleum Liquids (40 CFR part 60, subpart Ka (NSPS)) and the Standards of Performance for Volatile Organic Liquid Storage Vessels (including Petroleum Liquid Storage Vessels) (40 CFR part 60, Subpart Kb (NSPS)).