State of Utah 

GARY R. HERBERT 

Governor 

SPENCER J. COX 

Lieutenant Governor 

Office of the Governor 

Shaun McGrath, Regional Administrator 

U.S. Environmental Protection Agency, Region 8 

1595 Wynkoop Street 

Denver, Colorado 80202-1129 

Dear Mr. McGrath: 

December 10,2013 

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Re: Utah Area Designation Recommendations for the 2012 PM2.s NAAQS 

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The purpose of this letter is to recommend appropriate PM2.5 area designations for all 

areas of the State of Utah. These recommendations are made in response to EPA's December 14, 

2012, revision to the National Ambient Air Quality Standard (NAAQS) for PM25· Section 

1 07 (d) of the Clean Air Act (the Act) directs states to provide their recommendations to EPA 

following promulgation of new or revised NAAQS. 

EPA's 2012 NAAQS revision lowered the annual PM2.5 standard from15 flg/m3 to12 

flg/m3, and retained the 24-hour standard at 35 flg/m3. Utah has monitored PM2s since 2000 and 

has never identified any area within the state that violated the annual standard, even at 12 flg/m3. 

Data collected by Utah's PM2.s monitoring network shows all areas comply with this new 

standard 1

• Hence, I am not recommending at this time any new areas within the state that should 

be designated as "Nonattainment" for PM2.S· 

There are presently three distinct areas in Utah that have been designated nonattainment 

for PM2.5. The following areas are identified and described in 40 CFR 81.345: the Logan, UtahIdaho, PM2.5 nonattainment area; the Provo, Utah, PM2 5 nonattainment area; and the Salt Lake 

City, Utah, PM2.5 nonattainment area. Each was designated nonattainment for the 2006 24-hour 

NAAQS. 

The boundary for each of these areas was defined, in consultation with EPA, based on a 

rigorous analysis of nine factors. EPA's latest guidance on PM2 5 area designations2 identifies 

1 EPA has directed States to make their area designation recommendations based on ambient air data collected for 

calendar years 2010- 2012. This data has been quality assured and sent to EPA, and is available in EPA's AQS data 

system. 

2 "Initial Area Designations for the 2012 Revised Primary Annual Fine Particulate National Ambient Air Quality 

Standard", April16, 2013. 

Utah State Capitol, Suite 200 • P.O. Box 142220 • Salt Lake City, Utah 84114-2220 • Telephone (801) 538-1000 

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five factors to be considered in defining nonattainment area boundaries and notes that they are 

comparable to the factors that states have successfully used in making area designations for the 

1997 and 2006 PM2.5 NAAQS. These include air quality data, emissions and emissions related 

data, meteorology, geography I topography, and jurisdictional boundaries. 

My recommendation is that each of these existing nonattainment areas should specifically 

be designated as "Attainment I Unclassifiable" with respect to the 2012 annual NAAQS for 

PM2.s· 

All other areas of the state not identified as areas of nonattainment should also be 

designated as "AttainmentiUnclassifiable." The one exception to this recommendation concerns 

all Tribal Lands, over which Utah Division of Air Quality has no jurisdiction in such matters. It 

will be left to the EPA and the Tribes to designate these areas as they see fit. 

The submittal of any further documentation, which EPA determines is necessary to verify 

or otherwise meet the requirements of section 107 (d) of the Act, will be submitted by Bryce 

Bird, Director of the Division of Air Quality, and any questions your agency may have 

concerning this submittal should be addressed to Mr. Bird at (801)536-4064. 

Sincerely, 

~(4 tJ....~-{- Gary R. Herbert 

Governor