This action pertains to the petroleum refining industry and specifically to petroleum refinery sources that are subject to maximum achievable control technology (MACT) standards in 40 CFR part 63, subparts CC (Refinery MACT 1) and UUU (Refinery MACT 2) and new source performance standards (NSPS) in 40 CFR part 60, subpart Ja. This final action is the Petroleum Refining Sector Rulemaking which will address the EPA's obligation to perform Risk and Technology Reviews (RTR) for Petroleum Refinery MACT 1 and 2 source categories and will address issues related to the reconsideration of petroleum refinery NSPS subpart Ja. Petroleum refineries are facilities engaged in refining and producing products made from crude oil or unfinished petroleum derivatives. Emission sources include petroleum refinery-specific process units unique to the industry, such as fluid catalytic cracking units (FCCU) and catalytic reforming units (CRU), as well as units and processes commonly found at other types of manufacturing facilities (including petroleum refineries), such as storage vessels, flares, and wastewater treatment plants. Refinery MACT 1 regulates hazardous air pollutant (HAP) emissions from common processes such as miscellaneous process vents (e.g., delayed coking vents), storage vessels, wastewater, equipment leaks, loading racks, marine tank vessel loading, and heat exchange systems at petroleum refineries. Refinery MACT 2 regulates HAP from those processes that are unique to the industry, including sulfur recovery units (SRU) and from catalyst regeneration in FCCU and CRU.