The Minerals Management Service (MMS) is the designated federal agency with the authority to regulate oil and gas exploration and development activities in the central and western planning areas of the Gulf of Mexico Outer Continental Shelf (OCS) region. In addition to managing oil and gas resources in the region, the MMS is also charged with environmental management responsibilities, including those related to air quality. The National Environmental Policy Act (NEPA) mandates the type of environmental reviews or assessments that need to be conducted in the area to assess potential on-shore air quality impacts of exploration, development, production, and pipeline right of way activities. Some assessments require the application of air quality dispersion models to evaluate potential impacts.