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: 

Thank you for your recommendations dated April19, 2011 and November 20, 2015 regarding air 

quality designations for the State of Maryland for the 2010 revision to the primary National Ambient Air 

Quality Standard (NAAQS) for sulfur dioxide (S02). Reducing levels of S02 pollution is an important 

part of the U.S. Environmental Protection Agency's (EPA) commitment to a clean, healthy environment. 

Exposure to S02 can cause a range of adverse health effects, including narrowing of the airways which 

can cause difficulty breathing and increased asthma symptoms. This letter is to notify you of EPA's 

preliminary intentions regarding your recommended 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 of 75 parts per billion. Within 

one year after a new or revised standard is established, the Clean Air Act requires the Governor of each 

state to submit to EPA a list of all areas in the state, with recommendations 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. On July 25, 2013, EPA designated 29 areas in 

16 states as nonattainment, but did not at that 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 current round of designations, to be completed by July 2, 2016, addresses two groups of 

areas: (1) areas that have newly monitored violations of the 2010 S02 NAAQS based on the most recent 

three calendar years of certified monitored ambient air quality data; and (2) areas that contain any 

stationary source that had not been announced as of March 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 of S02 with an annual average emission rate of at least 0.45 pounds of S02/mmBTU. 

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

0 Printed on 100% recycled/recyclable paper with 100% post-consumer fiber and process chlorine free. 

Customer Service Hotline: 1-800-438-2474 
After 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) of counties: 

Area Name 

Anne Arundel County and 

Baltimore County* 

County 

Anne Arundel County (p ), 

Baltimore County (p) 

Additionally, after carefully considering Maryland's recommendations 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 area represents a modification 

to the designation that you have recommended. 

The enclosed Technical Support Document provides a detailed analysis that supports our 

intended designation decisions. If your state has additional information that EPA should consider prior 

to finalizing these designations, please submit it to us by April19, 2016. We also will be publishing a 

notice in the Federal Register announcing a 30-day period for the public to provide input on EPA's 

intended designation decisions. We will promulgate the designations for these areas by July 2, 2016. 

We will designate all other previously undesignated areas in the state on a schedule consistent with the 

prescribed timing of the court order, i.e., by December 31, 2017, or December 31, 2020. 

We look forward to a continued dialogue with you and your staff as we work together to 

complete the area designations and implement the 2010 primary S02 standard. For additional 

information regarding designations under the so2 standard, please visit our website at 

www. epa.gov/so2designations. 

Should you have any questions, please do not hesitate to call me, or have your staff contact 

Mr. Matt Colip, EPA's Maryland Liaison, at 215-814-5439. 

Shawn M. Garvin 11~ Regional Administrator 

Enclosure 

cc: The Honorable Ben Grumbles 

Secretary, Maryland Department of the Environment 

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