UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION Ill

The Honorable Larry Hogan Governor 100 State Circle 1650 Arch Street Philadelphia, Pennsylvania 19103-2029 

### FEB 1 6 2016

Annapolis, Maryland 21401-1925 Dear Governor Hogan: Thankyou for your recommendations dated April19, 2011 and November 20, 2015 regarding air quality designations for the State ofMaryland for the 2010 revision to the primary National Ambient Air Quality Standard (NAAQS) for sulfur dioxide (S02). Reducing levels ofS02 pollution is an important part ofthe U.S. Environmental Protection Agency's (EPA) commitment to a clean, healthy environment. Exposure to S02 can cause a range ofadverse health effects, including narrowing ofthe airways which can cause difficulty breathing and increased asthma symptoms. This letter is to notify you ofEPA's preliminary intentions regarding yourrecommended designations. On June 3, 2010, EPA strengthened the health-based or "primary" standard for S02 by establishing a standard for 1-hour average S02 concentrations at a level of75 parts per billion. Within one year after a new or revised standard is established, the CleanAir Actrequires the Governor ofeach state to submit to EPA a list ofall areas in the state, withrecommendations for whether each area meets the standard. Through an interactive process, EPA considers the recommendations and then promulgates designations for all areas across the country. OnJuly 25, 2013, EPA designated 29 areas in 16 states as nonattainment, but did not atthat time designate other areas. Pursuant to a March 2, 2015, court-ordered schedule,1 EPA must complete the remaining S02 designations by three specific deadlines: July 2, 2016, December 31,2017, and December 31,2020. This currentround ofdesignations, to be completed by July 2, 2016, addresses two groups of areas: (1) areas that have newly monitored violations ofthe 2010 S02NAAQS based onthe most recent three calendar years ofcertified monitored ambient air quality data; and (2) areas that contain any stationary source that had not been announced as ofMarch 2, 20 15 for retirement, and that according to EPA's Air Markets Database emitted in 2012 either (i) more than 16,000 tons ofS02 or (ii) more than 2,600 tons ofS02 with an annual average emission rate ofat least 0.45 pounds ofS02/mmBTU.

1Sierra Club v. McCarthy, No. 3-13-cv-3953 (SI) (N.D. Cal. Mar. 2, 2015).



## 0 Printedon 100% recycled/recyclablepaper with 100%post-consumer fiber andprocess chlorine free. Customer ServiceHotline: 1-800-438-2474After carefully considering Maryland's recommendations and other available technical information, EPA intends to designate as nonattainment the following area, which includes the following portions (p) ofcounties: Area Name Anne Arundel County and Baltimore County* County Anne Arundel County (p), Baltimore County (p) Additionally, after carefully considering Maryland'srecommendations and other available technical information, EPA intends to designate as unclassifiable/attainment the following area, which includes

**t~e** following city: Area Name City Baltimore City Baltimore City The asterisk(*) indicates the designation for this intended nonattainment arearepresents a modification to the designation thatyouhave recommended. The enclosed Technical SupportDocumentprovides a detailed analysis that supports our intended designation decisions. Ifyour state has additional informationthat EPA should considerprior to finalizing these designations, please submit itto us by April19, 2016. We also will be publishing a notice inthe FederalRegister announcing a 30-day period for the public to provide input onEPA's intended designation decisions. We will promulgate the designations for these areas by July 2, 2016. We will designate all otherpreviously undesignated areas inthe state on a schedule consistent withthe prescribed timing ofthe court order, i.e., by December 31, 2017, or December 31, 2020. We look forward to a continued dialogue withyou and your staffas we work together to complete the area designations and implement the 2010 primary S02 standard. For additional informationregarding designations under the so2 standard, please visit our website at www.epa.gov/so2designations. Should youhave any questions, please do nothesitate to call me, or have your staffcontact Mr. Matt Colip, EPA's Maryland Liaison, at 215-814-5439.



# 11~ Shawn M. Garvin Regional Administrator Enclosure

cc: The Honorable Ben Grumbles Secretary, Maryland Department ofthe Environment

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