727 Proposed designation recommendations for the 1-hour sulfur dioxide national ambient air quality standard
Proposed Designation Recommendations for the 1-Hour Sulfur Dioxide National Ambient Air Quality Standard [41 Pa.B. 2283]
[Saturday, April 30, 2011]On June 2, 2010, the United States Environmental Protection Agency (EPA) issued a revised 1-hour sulfur dioxide (SO2) National ambient air quality standard, (NAAQS), which became effective on August 23, 2010. See 75 FR 35520 (June 22, 2010). The new short-term standard, 75 parts per billion (ppb), based on the 3-year average of the annual 99th percentile of 1-hour daily maximum concentrations, is designed to protect public health by reducing short-term exposure to elevated SO2 concentrations. Current scientific evidence links health effects including difficulty breathing and increased asthma symptoms to short-term exposure to SO2 emissions. Studies also show an association between short-term SO2 exposure and increased visits to emergency departments and hospital admissions for respiratory illnesses—particularly in at-risk populations including children, the elderly and asthmatics.
In accordance with section 107(d) of the Clean Air Act (42 U.S.C.A. § 7407(d)), the governor of each state must submit designation recommendations to the EPA by June 2, 2011. Final designations will be promulgated by the EPA in June 2012. Attainment demonstrations submitted to the EPA in June 2014 must prescribe actions taken to meet the standard as expeditiously as possible, but no later than August 2017.
According to information compiled for the latest emissions inventory (2008), large stationary sources contribute almost 90% of the SO2 emissions in this Commonwealth, with most of those emissions coming from electric generation units.
The Department of Environmental Protection (Department) is seeking public input on the following proposed designation recommendations for the 1-hour SO2 NAAQS:
• Allegheny, Beaver, Indiana and Warren Counties as nonattainment areas.
• The remainder of this Commonwealth would be identified as ''unclassifiable'' areas.
The recommendations for nonattainment areas are based only on air quality monitoring data for 2008-2010; monitors in these counties exceed the 1-hour standard. The EPA suggested that initial state designation recommendations of ''unclassifiable'' would not be unexpected for areas without violations at an air quality monitor. States may provide additional information for larger or smaller nonattainment areas, which would most likely be based on refined dispersion modeling. However, refined dispersion modeling for large sources of SO2 emissions in this Commonwealth has not been conducted due to the EPA's delayed issuance of its guidance for area designations on March 24, 2011. Prior to the issuance of final designations in June 2012, the Department anticipates that modeling will be conducted for certain sources in accordance with the EPA guidance. The EPA will notify states at least 120 days before the final designations if the EPA intends to modify state designation recommendations.
This proposal is available on the Department's web site at http://www.depweb.state.pa.us or through the following contact person.
Written comments on the recommendations should be sent to Arleen Shulman, Chief, Air Resource Management Division, Bureau of Air Quality, Department of Environmental Protection, P. O. Box 8468, Harrisburg, PA 17105-8468, ashulman@state.pa.us no later than 4 p.m. on May 25, 2011. Written comments including e-mail submittals must include the name, affiliation, mailing address and telephone number of the interested person.
MICHAEL L. KRANCER,
Secretary[Pa.B. Doc. No. 11-727. Filed for public inspection April 29, 2011, 9:00 a.m.]
