Fact Sheet — Final Area Designations for the 2010 Sulfur Dioxide 1-Hour Primary National Ambient Air Quality Standard - Round 4 ACTIONS • On December 21, 2020, the U.S. Environmental Protection Agency (EPA) took another step to implement the health-based national ambient air quality standard (NAAQS) for sulfur dioxide (SO2) set in 2010. EPA has identified or "designated" areas: o "nonattainment" - not meeting the 1-hour health based SO2 NAAQS (9 areas in 7 states), o "unclassifiable" - not enough information to make a determination (2 areas in 1 state), and o "attainment/unclassifiable" - meeting the standard and not contributing to a violation of the standard (33 areas in 19 states). • On June 3, 2010, EPA strengthened the health-based or "primary" SO2 NAAQS by establishing a 1-hour standard at a level of 75 parts per billion. On July 25, 2013, EPA designated 29 areas in 16 states as nonattainment. A March 2, 2015, court-ordered schedule required the Agency to complete the remaining SO2 designations by three specific deadlines: July 2, 2016; December 31, 2017; and December 31, 2020. • These final designations will take effect on April 30, 2021. REQUIREMENTS FOR DESIGNATED NONATTAINMENT AREAS • The Clean Air Act requires air agencies to take steps to control pollution in SO2 nonattainment areas. Those steps may include additional controls on industrial facilities. • State and local governments detail these steps in plans that demonstrate how they will meet the SO2 standard. Those plans are known as state implementation plans (SIPs). States have 18 months after the effective date of final designations to develop and submit their plans to EPA. • Once designated, nonattainment areas are subject to Nonattainment New Source Review requirements. New Source Review is a permitting program for industrial facilities to ensure that new and modified sources of pollution do not impede progress toward cleaner air. • Nonattainment areas are required to meet the standard as quickly as possible, but no later than five years after the effective date of final designation. ------- BACKGROUND • The Clean Air Act requires EPA to issue designations after the agency sets a new NAAQS or revises an existing standard. Areas not meeting the standard are designated "nonattainment." • In June 2010, EPA set a 1-hour, health-based NAAQS for SO2 at 75 parts per billion (ppb), which is met when the 3-year average of the annual 99th percentile of daily maximum 1- hour average concentrations of S02 does not exceed 75 ppb. The revised standard is improving public health protection, especially for children, the elderly and people with asthma. These groups are susceptible to health problems, including narrowing of the airways which can cause difficulty breathing and increased asthma symptoms, associated with breathing SO2. FOR MORE INFORMATION • For more information on the designation process for the 2010 SO2, please visit EPA's Web site at https://www.epa.eov/sulfur-dioxide-desienations. ------- EPA's Final Area Designations for the 2010 Sulfur Dioxide (SO2) Primary National Ambient Air Quality Standard (NAAQS) - Round 4 State County/Parish EPA's Final Area EPA's Final Designation AL Shelby Shelby County (partial)* Attainment/Unclassifiable GA Floyd Floyd County Attainment/Unclassifiable HI Honolulu Honolulu County Attainment/Unclassifiable HI Honolulu Honolulu County Attainment/Unclassifiable IL Macon Macon County Attainment/Unclassifiable IN Porter Porter County Attainment/Unclassifiable KY Henderson Henderson County (partial)** Webster County (partial)** Nonattainment LA East Baton Rouge East Baton Rouge Parish Attainment/Unclassifiable LA St. Charles St. Charles Parish Attainment/Unclassifiable LA St. James St. James Parish Attainment/Unclassifiable LA West Baton Rouge West Baton Rouge Parish Attainment/Unclassifiable MD/WV Allegany (MD) Mineral (WV) Allegany County, MD Mineral County, WV Attainment/Unclassifiable MO Iron Iron County Attainment/Unclassifiable MO New Madrid New Madrid County (partial)** Nonattainment NE Douglas Douglas County Attainment/Unclassifiable NY Cayuga Seneca Tompkins Cayuga County Seneca County Tompkins County Attainment/Unclassifiable NY St. Lawrence St. Lawrence County (partial)** Nonattainment NC Buncombe Limestone Township - Buncombe County Attainment/Unclassifiable NC Haywood Beaverdam Township - Haywood County Attainment/Unclassifiable NC Person Cunningham Township - Person County Attainment/Unclassifiable ND Williams Williams County Attainment/Unclassifiable OK Garfield Garfield County Attainment/Unclassifiable ------- State County/Parish EPA's Final Area EPA's Final Designation OK Mayes Mayes County Attainment/Unclassifiable OK Muskogee Muskogee County Attainment/Unclassifiable PA York York County Attainment/Unclassifiable PA York York County Attainment/Unclassifiable TX Bexar Bexar County Attainment/Unclassifiable TX Harrison Harrison County Unclassifiable TX Howard Howard County (partial)** Nonattainment TX Hutchinson Hutchinson County (partial)** Nonattainment TX Jefferson Jefferson County Attainment/Unclassifiable TX Navarro Navarro County (partial)** Nonattainment TX Orange Orange County Unclassifiable TX Robertson Robertson County Attainment/Unclassifiable TX Titus Titus County (partial)* Attainment/Unclassifiable VA Alleghany City of Covington - Alleghany County Attainment/Unclassifiable VA Botetourt Botetourt County Attainment/Unclassifiable VA Giles Giles County (partial)** Nonattainment WA Chelan Douglas Chelan County Douglas County Attainment/Unclassifiable WA Whatcom Whatcom County (partial)** Nonattainment Wl Outagamie Outagamie County (partial)** Nonattainment WY Carbon Carbon County Attainment/Unclassifiable WY Fremont Fremont County (partial)* Attainment/Unclassifiable WY Converse Converse County Attainment/Unclassifiable WY Sweetwater Sweetwater County (partial)* Attainment/Unclassifiable * The other portion of the area was designated previously. ** EPA is designating the remaining undesignated portion of the area (i.e., the remaining portion of the county outside of EPA's final nonattainment area boundary) as attainment/unclassifiable in this round of designations. ------- |