UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION Ill 1650 Arch Street Philadelphia, Pennsylvania 19103-2029



### The Honorable Jack Markell Governor ofDelaware Tatnall Building 150 William Penn Street, 2nd Floor Dover, Delaware 19901 Dear Governor Markell: 

## AUG 19 Z014

Thank you for your recommendations, dated November 21, 2013, regarding air quality designations for the 2012 revised primary annual fine particle (PM2.s) National Ambient Air Quality Standard (NAAQS) throughout Delaware. I appreciate the information Delaware shared with the U.S. Environmental Protection Agency (EPA) as we move forward to improve PM2.s air quality. This letter is to notify you ofEPA'spreliminaryresponse to Delaware's recommendations and to inform you ofour approach for completing the initial area designations for the 2012 revised primary annual PM2.s standard. On December 14,2012, EPApromulgated a revised primary annual PM2.s NAAQS (78 FR 3086, January 15, 2013). In that action, EPA revised the primary annual PM2.s standard, strengthening it from 15.0 micrograms per cubic meter (!-Lg/m3) 

### to 12.0 !-Lg/m3; 

### retained the existing 24-hour PM2

.sstandard at 35 1-Lg/m3; 

### retained the existing 24-hour PM10 (coarse particle) standard at 150 I-Lg/m3; 

### and retained the current suite ofsecondary PM standards. EPArevised the primary annual PM2.s standard based on an integrated assessment ofan extensive body of new scientific evidence, which substantially strengthens ourbody ofknowledge regarding PM2

.srelated health effects. The revised primary annual PM2

.sstandard will provide increased protection for children, older adults, persons with pre-existing heart and lung disease, and other at-risk populations against an array ofPM2.s-related adverse health effects, including premature mortality, increased hospital admissions and emergency department visits, and development and exacerbation ofchronic respiratory disease. History shows us that better health and cleaner air go hand-in-hand with economic growth. Working closely with the states and tribes, EPA is implementing the standards using a commonsense approach that improves air quality and minimizes the burden on state, local, and tribal governments. As part ofthis routine process, EPA is working with the states and tribes to identify areas in the country that meetthe standards and those that need to take steps to reduce PM2.s air pollution. Within one year ofpromulgating a new or revised air quality standard, the Clean Air Act (CAA) requires the Governor ofeach state to submit to EPA a list ofall areas in the state, with a designation recommendation for each area. As a first step in implementing the 2012 annual PM2

.s standard, Governors were required to submit their designation recommendations, including appropriate area boundaries, by December 13, 2013.


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As required by the CAA, EPA thenpromulgates designations for all areas across the country. EPA designates an area as "nonattainment" ifit is violating the 2012 annual PM2.s NAAQS or ifit is contributing to a violation ofthe NAAQS in a nearby area. Consistent with designations for previous PM2.s standards, EPA intends to use a designation category of "unclassifiable/attainment" for areas that are monitoring attainment or do nothave monitors, but for which EPA has reason to believe are likely attainment and are not contributing to nearby violations. Additionally, EPA intends to designate as "unclassifiable" those areas where EPA cannot determine based on available information whether the area is meeting the NAAQS or where EPA has not determined that the area contributes to a nearby violation. Atthis time, EPA is proceeding with intended initial area designations using quality-assured, certified air quality monitoring data from 2011 to 2013. We have considered the annual PM2.s designation recommendations submittedby Delaware onNovember 21, 2013 and have reviewed the relevant technical information, including 2011-2013 air quality data. These data do not indicate any violation ofthe 2012 annual PM2

.sNAAQS in Delaware or contribution to any nearby area. Accordingly, EPA intends to designate the entire State ofDelaware as unclassifiable/attainment. EPA will make its preliminary designation decisions and supporting documentation available to the general public for review and comment. We will be announcing a 30-daypublic commentperiod shortly in the 

### Federal Register. After considering the additional information we receive, EPAplans to promulgate final annual PM2.s designations in December of2014. EPA is committed to working with the states and tribes to share the responsibility of reducing PM2

.s air pollution. Current and upcoming federal standards and safeguards

- including pollution reduction rules for powerplants, vehicles, and fuels -will ensure steady progress to reduce PM2 .s-forming pollution and will protectpublic health in communities across the country. We look forward to a continued dialogue with you and your staffas we work together to implementthe 2012 annual PM2

.s standard. Should you have any questions, please do not hesitate to contact me, or have your staffcontact Ms

. Arnie Howell, EPA' s Delaware Liaison, at (215) 814-5722 or howell.amie@epa.gov.


### Since;;,_

# If& 

# A.
Garvin Regional Administrator

cc: Honorable David Small, Secretary Department ofNatural Resources and Environmental Control Ali Mirzakhalili, Director Division ofAir Quality, Department ofNatural Resources and Environmental Control