The State ofNew Hampshire 

## Department ofEnvironmental 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 2010 Sulfur Dioxide 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 New Hampshire's certification ofadequacy for the 2010 National Ambient Air Quality Standard (NAAQS) for sulfur dioxide (S02) which was submitted to the United States Environmental Protection Agency, Region I (EPA) on September 13,2013. This supplemental information certifies to the EPA that New Hampshire' s State Implementation Plan (SIP) fulfills the "infrastructure" requirements established in paragraphs 11O(a)(1) and (2) ofthe Clean Air Act (CAA). New Hampshire is also requesting a change in its priority region classification for S02 episode plans in accordance with 40 CFR 51.150.
In order to approve New Hampshire's request to change to a Priority III region for S02 episode plans in accordance with 40 CFR 51.150(£), EPA has requested that New Hampshire supplement its September 13, 2013 SIP submittal with the most recent three years ofS02 monitoring data (2012 through 2014). Table 1below provides the requested annual S02ambient concentrations in parts per million (ppm) data for the most recent three year period (2012 through 2014) to supplement the S02monitoring data previously submitted in the September 2013 SIP. The data for 2012 and 2013 have been certified by the New Hampshire Department of Environmental Services, Air Resources Division (DES) and concurred on by EPA. All ofthe 2014 data has been reviewed for accuracy and the DES has issued a certification letter to EPA. Based on the values presented in Table 1 and those contained in the September 13, 2013 submittal, at no time was the 0.02 ppm Priority II S02threshold reached anywhere in the state.

www.des.nh.gov 29 Hazen Drive • PO Box 95 • Concord, NH 03302-0095 (603) 271-3503 • TDD Access: Relay NH 1-800-735-2964 .... J !_ )()/ ! @Ai'ijliiwlMr

. David Conroy, Air Programs Branch Chief (fypplememal In/ ormation - 0I0 Sut/itr Dioxide Standard Cerlificalion o(Adeguacv Page2 Map21. 20 15

Table 1: 502 Ambient Concentrations (ppm): Annual Arithmetic Mean in Each Year, 2012 -2014 Monitor Location 2012 2013 2014 Concord* 0.001 0.001 0.001 Londonderry 0.001 0.001 0.001 Manchester** 0.002



### -- -- Pembroke* 0.001 0.001 0.000 Peterborough 0.001 0

.001 0

.001 Portsmouth 0

.001 0.001 0.001 *Monitor is located within designated nonattainment area **Monitor was discontinued in Q2 of2012 Annual meansfrom AQSAMP450 Quick Look Report
Table 2 below provides the requested highest three (3)-hour S02 value and the number of times the 3-hour value equaled or exceeded 0.50 ppm in each year from 2012 through 2014. Based on the 3-hour values presented in Table 2 and those contained in the September 13, 2013 submittal, at no time was the 0.50 ppm Priority II S02threshold reached anywhere in the state.

Table 2: 502 Ambient Concentrations (ppm): Highest 3-Hour Value and Number ofTimes the 3-Hour Value Equaled or Exceeded 0.50 ppm in Each Year, 2012 -2014 Monitor Location 2012 2013 2014 Concord* 0.017 (0) 0.011 (0) 0.01 {0) Londonderry 0.005 {0) 0.009 (0) 0.007 (0) Manchester** 0.014 (0)



### -- - Pembroke* 0.042 (0) 0.024 (0) 0.021 (0) Peterborough 0.004 (0) 0.005 (0) 0.006 (0) Portsmouth 0.022(0) 0

.019 (0) 0.027 (0) *Monitori s located within desi gnated nonattainmentarea **Monitor was discontinued in Q2 of 2012 Maximum 3-hourbulk averages AQSAMP440 Maximum Values Report
Table 3 below provides the requested highest twenty four (24)-hour S02 value and the number oftimes the 24-hour value equaled or exceeded 0.10 ppm in each year from 2012 through 2014. Based on the 24-hour values presented in Table 3 and those contained inthe September 13, 2013 submittal, the Central New Hampshire Nonattainment Area (Pembroke monitor) is the only area ofNew Hampshire to have experienced ambient 24-hour S02 concentrations in the Priority II range in years 2009, 2010 and 2011. The 24-hour S02 concentrations in 2009, 2010 and 2011 rarely exceeded the 0.10 ppm level and in the most recent three year period the 24-hour S02concentrations have not reached the 0.10 ppm level. In addition, installation ofadvanced so2 control technology further diminishes the probability of future excursions above this level.Page3 Mav 2 T, 201 5

Table 3: 502 Ambient Concentrations (ppm): Highest 24-Hour Value and Number ofTimes the 24-Hour Value Equaled or Exceeded 0.10 ppm in Each Year, 2012 -2014 Monitor Location 2012 2013 2014 Concord* 0.006 (O) 0.007 (O) 0.006 (O) Londonderry 0.004 (O) 0.004 (0) 0.004 (O) Manchester** 0.007 (0)
- 

# - Pembroke* 0.008 (O) 0.006 (O) 0.005 (0) Peterborough 0.003 (O) 0.004 (0) 0.004 (0) Portsmouth 0

.006 (0) 0.009 (0) 0.008 (0) *Monitoris located within designated nonattainment area **Monitor was discontinued in Q2 of2012 Maximum 24-houraverages AQSAMP440 Maximum Values Report
Based on this supplemental S02monitoring data, New Hampshire qualifies as a Priority III region for so2 episode plans in accordance with 40 CFR 51

I 150(±) and hereby requests approval ofthis change. As a Priority III region for S02 , New Hampshire is no longer required to develop episode plans in accordance with 40 CFR 51.1529(c). The requested supplemental S02 monitoring data and New Hampshire's request and approval to change to a Priority III region for S02episode plans, satisfies the contingency plan requirements with respect to subparagraph 110(a)(2)(G) ofthe CAA.
In addition, in the September 13, 2013 S02 submittal, DES had included several New Hampshire statutes for incorporation into the New Hampshire SIP. DES is now withdrawing the following statute from the submittal: NH RSA 125-C:15, Enforcement.
Ifyou have any
.questions, please contactme at (603) 271-1088 or via 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,

# ~ 0

# ~-1!1/.1--
Craig A. Wright Director Air Resources Division