This action will address the EPA’s technology review of the National Emission Standards for Hazardous Air Pollutants (NESHAP) for 40 CFR part 63, subpart Y, Marine Tank Vessel Loading Operations (MTVLO). The MTVLO NESHAP was promulgated pursuant to Clean Air Act (CAA) section 112(d) on September 19,1995; most recently, on April 21, 2011, the Agency finalized its residual risk and technology review (RTR) of the MTVLO NESHAP pursuant to CAA section 112(d)(6). The MTVLO MACT standards apply to major sources and regulate hazardous air pollutant (HAP) emissions resulting from loading operations conducted at marine terminals in which liquid commodities, such as crude oil, gasoline, natural gas, and other fuels or chemicals are pumped from the terminal’s large, above-ground storage tanks through a network of pipes into a storage compartment (tank) on the vessel. The HAP emission sources at MTVLO facilities include but are not limited to open tank hatches, overhead vent systems, hatch covers or domes, pressure or vacuum relief valves, seals, and vents. The HAP emitted by these sources include benzene, toluene, hexane, xylene, and ethyl benzene. This action will implement the technology review requirements of CAA section 112(d)(6) that requires the EPA to review and revise the MACT standards as necessary, taking into account developments in practices, processes and control technologies, no less often than every 8 years.