Outer Continental Shelf Air Permits

Outer Continental Shelf (OCS) Air Regulations, found at 40 CFR part 55, establish the applicable air pollution control requirements for facilities subject to Clean Air Act (CAA) section 328. These regulations apply to OCS sources located beyond state seaward boundaries, with the exception of OCS sources located in the Gulf of Mexico west of 87.5° longitude (i.e. offshore TX, LA, MS, AL) and areas offshore the North Slope Borough of Alaska. Sources in the latter areas are under the authority of the Department of Interior's Bureau of Ocean Energy Management  (DOI-BOEM) and Bureau of Safety and Environmental Enforcement (DOI-BSEE). DOI-BOEM and DOI-BSEE work closely together and have specific roles and responsibilities in managing certain activities on the OCS.

OCS Air Regulations in Part 55 include provisions related to permitting, monitoring, reporting, fees, compliance, and enforcement. OCS sources locating within 25 nautical miles of a state seaward boundary, commonly known as "inner OCS sources", are required to comply with the air quality requirements of the corresponding onshore area (COA), which include New Source Review preconstruction permitting and/or Part 70 Title V operating permit program requirements and other state and local requirements that apply to OCS sources. The EPA Administrator is required to update such requirements as necessary to maintain consistency with onshore regulations in what is commonly known as a consistency update. EPA is maintaining a list of OCS air regulations consistency updates in the Consistency Updates Index. These air pollution sources may also be subject to New Source Performance Standards and National Emissions Standards for Hazardous Air Pollutants promulgated under section 112 of the CAA. 

OCS sources locating beyond 25 nautical miles from the state seaward boundary are subject to only federal air quality requirements and may need OCS permits complying with the EPA’s Prevention of Significant Deterioration (PSD) preconstruction permit program regulations and/or the Part 71 Title V operating permit program requirements. These air pollution sources may also be subject to New Source Performance Standards and National Emissions Standards for Hazardous Air Pollutants. OCS sources locating beyond 25 nautical miles from the state seaward boundary, commonly known as “outer OCS sources,” are not subject to any specific COA requirements.

OCS Air Regulations are generally implemented and enforced by the EPA Regional Offices, but this authority may be delegated to state or local air permitting agencies that meet specific criteria. To date, EPA has delegated authority to administer OCS Air Regulations to three state permitting authorities (Delaware, Maryland, and Virginia) and four local permitting authorities in California (Santa Barbara, San Luis Obispo, South Coast and Ventura County).

Since EPA’s promulgation of the Part 55 regulations in 1992, most OCS sources that obtained permits were involved in oil and gas exploration, development, or production. OCS sources do not include Deepwater ports, which are engaged in the transportation of oil and natural gas, including sources involved in liquefied natural gas (LNG) import and export. Information on Deepwater port permitting can be found in EPA’s LNG Regulatory Roadmap and at the “Air Permitting for Deepwater Port Act Projects in the South Central Region” webpage. You may also contact the appropriate EPA Region.

More recently, EPA has received OCS permit applications for offshore wind farms. To facilitate the preparation and review of OCS permit applications for offshore wind farms, EPA is maintaining a compilation of recent OCS permitting actions at the OCS Wind Energy Database. For additional information on application of CAA permitting requirements to offshore wind energy, please contact the appropriate EPA Region.