The State ofNew Hampshire 

## DepartmentofEnvironmental Services

Mr. David Conroy, Chief Air Programs Branch Thomas S. Burack, Commissioner

May 21,2015

U.S. Environmental Protection Agency, Region I 5 Post Office Square, Suite 100 Boston, MA 02109-3912
Re: Supplemental Information for Certification ofAdequacy for 2008 Ozone Standard SIP Submittal (Infrastructure SIP)
Dear Mr. Conroy:
As Governor Hassan's designee, I am enclosing for your review and approval the requested supplemental information to NewHampshire's certification ofadequacy for the 2008 National Ambient Air Quality Standard (NAAQS) for ozone which was submitted to the United States Environmental Protection Agency, Region I (EPA) on December 31, 2012. This supplemental information supports NewHampshire's certificationthat NewHampshire's State Implementation Plan (SIP) fulfills the "infrastructure" requirements established in paragraphs llO(a)(l) and (2) ofthe Clean Air Act (CAA). Specifically, with respect to subparagraph II0(a)(2)(G) ofthe CAA, EPA has requested additional ozone monitoring data (the mostrecent 3 years ofdata for years 2012 through 2014) to supportNewHampshire's exemption request in accordance with 40 CFR 51.152(d)(l). As stated in NewHampshire's 2008 Ozone Standard Infrastructure SIP submittal, NewHampshire is a Priority I region for ozone as defined in 40 CFR 51.150(b)(5). While some areas in New Hampshire have experienced ozone levels that marginally exceededthis threshold, those incidents are infrequent, and their magnitude remains consistent with a general downtrend in ambient ozone concentrations across the region. 40 CFR 51.152 establishes contingency planning requirements for certain priority regions. As provided in 52.152(d)(l), the EPA administrator may exempt Priority I regions from contingencyplanning requirements ifthose regions have been designated as attainment or unclassifiable for the NAAQS. EPA has designated all areas ofNew Hampshire as "unclassifiable/attainment" for the 2008 ozone NAAQS.

www.des.nh.gov 29 Hazen Drive • PO Box 95 • Concord, NH 03302-0095 (603) 271-3S03 • TDD Access: Relay Nil 1-800-735-2964Mr. David Conroy, Chief, Air Programs Branch SupplementalInformation- 2008 Ozone Standard Certification o[Adequacv Page2 May21. 2015
A table was included in the December 2012 SIP submittal that presented the maximum one-hour values in parts permillion (ppm) for ozone and the number oftimes the 100 parts per billion (ppb) threshold was exceeded each year from 2005 through 2012. Table 1belowprovides the requested ozone data for the most recentthree year period (2012 through 2014) to supplement the datapreviously submitted. The data for 2012 and 2013 have been certified by the NewHampshire Department ofEnvironmental Services, Air Resources Division (DES) and concurred on byEPA. The 2014 data has been reviewed for accuracy and DES has issued a certification letter to EPA.

Table 1: Maximum 1-Hour Values (ppm) for Ozone and Number ofTimes 0.10 ppm Threshold Was Exceeded Each Year (2012-2014) Monitor Location 2012 2013 2014 Camp Dodge 0.070 (0) 0.068 (0) 0.073 (0) Concord 0.076 (O) 0.071 (0) 0.078 {0) Keene 0.081 (O) 0.073 (0) 0.087 (0) Laconia 0.074 (0) 0.069 (0) 0.075 (0) Lebanon 0.077 {0) 0.070 (0) 0.079 (0) Londonderry 0.109 (1) 0.082 (O) 0.085 (0) Mt. Washington Summit 0.078 (O) 0.080 (0) 0.076 (0) Nashua 0.112 (1) 0.081(0) 0.084 (0) Peterborough 0.091 (0) 0.085(0) 0.090 (O) Portsmouth 0.101 (1) 0.097 (0) 0.088 (0) Rye 0.087 (0) 0.087 (0) 0.089 (0) Valuesfrom AMP440 Maximum Values Report
As the above data and previously submitted data show, maximum ozone levels since 2005 have not come close to the significant harm level of 1,200 )..lg/m3 (0.6 ppm), 2-hour average, identified at 40 CFR 51.151. Infact, DES does not envision any circumstances that would produce ambient ozone concentrations approaching such as extreme level in the future

. On this basis,NewHampshire appears to qualify for and requests the exemption from contingencyplanning in accordance with 40 CFRPart 52.152(d)(1).
Ifyou have any questions, please contact me at (603) 271-1088 orvia email at Craig

.Wright@des.nh

.gov, or Michele Roberge ofmy staffat (603) 271-6793 or via email at Michele.Roberge@des.nh.gov.

cc: Anne Arnold, EPA Region I Richard Burkhart, EPA Region I Sincerely,

Craig A. Wright Director Air Resources Division