Revision to the 

New Hampshire 

State Implementation Plan 

To Meet the Requirements of 

Clean Air Act Section 110(a)(2)(D)(i) 

March 2008 

Prepared by 

The New Hampshire 

Department of Environmental Services 
Table of Contents 

1.0 Summary................................................................................................................. 1 

2.0 Background............................................................................................................. 1 

3.0 Significant Contribution and Interference with Maintenance (Section 

110(a)(2)(D)(i)(I))................................................................................................... 5 

3.1 Ozone and PM2.5 Attainment Status of Downwind Areas.................................. 6 

3.2 Air Quality Dispersion Modeling ....................................................................... 6 

3.2.1 Identification of Models and Domain Used.................................................... 6 

3.2.2 Emissions Processing Methodology ............................................................... 9 

3.2.3 Summary of USEPA’s CAIR Modeling Results.......................................... 12 

3.2.4 Summary of OTC and NHDES Modeling Results ....................................... 14 

3.2.5 CALGRID Zero Out of New Hampshire...................................................... 17 

3.2.6 Monitoring Data and Back Trajectories........................................................ 20 

4.0 Prevention of Significant Deterioration and Protection of Visibility (Section 

110(a)(2)(D)(i)(II)) ............................................................................................... 27 

5.0 Administrative Materials ...................................................................................... 29

List of Figures 

Figure 2-1. Ozone Nonattainment Areas in New Hampshire ............................................. 3 

Figure 3-1. Map of the CMAQ/CALGRID Modeling Domain.......................................... 7 

Figure 3-2. Map of the RPO National Domain................................................................... 8 

Figure 3-3. QA/QC Plot of Surface Source CO Emissions.............................................. 10 

Figure 3-4. QA/QC Plot of Surface Source VOC Emissions........................................... 10 

Figure 3-5. QA/QC Plot of Point Source NOx Emissions................................................ 11 

Figure 3-6. QA/QC Plot of Point Source SO2 Emissions................................................. 11 

Figure 3-7. CMAQ SIP Quality Modeling Results for 2009 OTC OTB/OTW vs. 2002 

Design Value Factors............................................................................................ 15 

Figure 3-8. Plot of the Maximum (Worst-case) Difference in Model Predicted 8-Hour 

Ozone Concentrations Between 2009 OTB/OTW and Zero Out of New 

Hampshire ............................................................................................................. 18 

Figure 3-9. Historical 8-Hour Ozone Monitoring Data for Maine ................................... 21 

Figure 3-10. HYSPLIT Back Trajectories for 8-Hour Ozone Exceedances Chicopee and 

Worcester, Massachusetts 2003-2005.................................................................. 25 

Figure 3-11. HYSPLIT Back Trajectories for 8-Hour Ozone Exceedances Newbury, 

Haverhill, and Chelmsford, Massachusetts 2003-2005 ........................................ 25 

Figure 3-12. HYSPLIT Back Trajectories for 80Hour Ozone Exceedances Fairhaven and 

Truro, Massachusetts 2003 - 2005........................................................................ 26 

Figure 3-13. HYSPLIT Back Trajectories for 8-Hour Ozone Exceedances Boston (Long 

Island) and Lynn, Massachusetts 2003-2005........................................................ 26 
List of Tables 

Table 3-1. Summary of CAIR Modeling Results for Ozone for New Hampshire, Maine, 

and Massachusetts (in ppb)................................................................................... 13 

Table 3-2. Summary of CAIR Modeling Results for Annual PM2.5 for New Hampshire, 

Maine, and Massachusetts (in micrograms per cubic meter)................................ 14 

Table 3-3. Modeling Summary of Monitors in New Hampshire and Downwind Areas 

(ppb)...................................................................................................................... 16 

Table 3-4. CMAQ/CALGRID Screening Results for Zero Out New Hampshire Scenario 

(ppb)...................................................................................................................... 19 

Table 3-5. Summary of Monitored 8-Hour Ozone Exceedances in Massachusetts for 

2003-2005 ............................................................................................................. 22 

Table 4-1. Major Source Emission Thresholds for Ozone Precursors.............................. 28 

List of Appendices 

Appendix A – Public Notice for SIP Revision 

Appendix B – Public Comments and NHDES Response 

Appendix C – Certification of Public Process 

Appendix D – Evidence of Legal Authority 
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NHDES FINAL March 2008 

1.0 Summary 

The New Hampshire Department of Environmental Services (NHDES) submits this 

State Implementation Plan (SIP) revision to fulfill the requirements of the United States 

Environmental Protection Agency’s (USEPA’s) Findings of Failure to submit a SIP meeting 

the requirements of Clean Air Act (CAA) Section 110(a)(2)(D)(i).1 (70 FR 21147.) NHDES 

submits this SIP in accordance with CAA Section 110(a)(2)(D)(i), the general SIP submittal 

requirements of 40 CFR Part 51 Appendix V, and guidance provided by USEPA.2 

This SIP certifies that sources and emission activities in New Hampshire do not 

contribute to nonattainment of the 8-hour ozone National Ambient Air Quality Standard 

(NAAQS) and the 1997 fine particulate matter (PM2.5) NAAQS in other states and do not 

interfere with maintenance of the 8-hour ozone NAAQS and the 1997 PM2.5 NAAQS in other 

states. This SIP also confirms that New Hampshire’s SIP already contains provisions to 

prohibit major sources from interfering with measures in other states to prevent significant 

deterioration through the Prevention of Significant Deterioration (PSD) and nonattainment 

New Source Review (NSR) provisions. In addition, NHDES confirms that the current SIP, 

in the PSD and NSR regulations, contains provisions to prevent sources from interfering with 

measures to protect visibility according to the 1980 visibility requirements. NHDES along 

with other states in Mid-Atlantic/Northeast Visibility Union (MANE-VU) and other Regional 

Planning Organizations (RPOs) are analyzing the 1999 regional haze requirements and will 

make a determination concerning these provisions in the December 2007 regional haze SIP 

submittal. 

On January 15, 2008, NHDES published in a statewide newspaper a public notice 

soliciting comment and announcing the opportunity for the public to request a public hearing 

for this SIP Revision. After the public comment period and public hearing, if requested, 

NHDES will document and review any comments received and provide a response, if 

necessary. NHDES will amend this SIP Revision, as necessary, and resubmit it, with the 

additional documents required to certify the SIP submittal. 

2.0 Background 

On July 18, 1997, the USEPA adopted a new National Ambient Air Quality Standard 

(NAAQS) for ozone and fine particulate matter (PM2.5). The new 8-hour ozone NAAQS is 

0.08 parts per million (ppm) based on the three-year average of the annual fourth-highest 

daily maximum 8-hour average ozone concentration measured at each monitor. The original 

1997 PM2.5 NAAQS was 65 μg/m3 based on the three-year average of the 98th percentile of 

 

1 Finding of Failure to Submit Section 110 State Implementation Plans for Interstate Transport for the National 

Ambient Air Quality Standards for 8-Hour Ozone and PM2.5, 70 FR 21147 (April 25, 2005). 2

 Memorandum from William Harnett, Director, Air Quality Policy Division, USEPA to Regional Air Quality 

Directors, USEPA, dated August 15, 2006. 
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NHDES FINAL March 2008 

24-hour concentrations and 15 μg/m3 based on the three-year average of the weighted annual 

mean concentration. The 24-hour PM2.5 standard was revised recently to 35 μg/m3 based on 

the three-year average of the 98th percentile of 24-hour concentrations. This SIP submittal 

covers the new 8-hour ozone NAAQS and the 1997 PM2.5 NAAQS. 

Portions of Hillsborough, Merrimack, Rockingham, and Strafford Counties are 

designated as moderate 8-hour ozone nonattainment areas. The rest of the state is designated 

attainment except for the portions designated as maintenance areas for the 1-hour ozone 

NAAQS. These maintenance areas include Cheshire County for which there was incomplete 

data on the date of the designation for the 1-hour ozone NAAQS and portions of the 4-

counties (Hillsborough, Merrimack, Rockingham, and Strafford) that were designated 

nonattainment under the 1-hour ozone NAAQS and are currently designated as attainment 

under the 8-hour ozone NAAQS. The entire state is designated attainment for the 1997 PM2.5

NAAQS. Figure 2-1 shows the current 8-hour ozone nonattainment areas (and previous 1-

hour boundaries). 

 Section 110(a)(1) of the Clean Air Act (CAA) requires States to submit a State 

Implementation Plan (SIP) revision to provide for the implementation, maintenance and 

enforcement of the new or revised NAAQS. Section 110(a)(2) lists the elements that the SIP 

revision must include. Section 110(a)(2)(D) specifically relates to the transport of air 

pollution and the contribution or interference with other states’ air quality. 

Section 110(a)(1) says that states must submit the SIP revisions three years after the 

promulgation of a new or revised NAAQS. Because of litigation over both the 8-hour ozone 

and 1997 PM2.5 NAAQS and the need for additional monitoring of PM2.5, the SIP submittals 

have been delayed. On April 25, 2005, the USEPA published a finding that States had failed 

to submit the SIP revisions for the ozone and 1997 PM2.5 NAAQS3. This finding was limited 

to the requirements of Section 110(a)(2)(D)(i), the interstate transport provisions. With this 

finding, a 24-month sanction clock was started requiring the USEPA to issue a final Federal 

Implementation Plan (FIP) unless a State makes the required SIP submission and the USEPA 

approves the submission within the 24-month period by May 25, 2007. 

 The USEPA issued this finding of failure to submit SIPs as part of a Consent Decree 

between the USEPA and plaintiffs, who sued the USEPA for failure to take action on the SIP 

submission requirements for the new 8-hour ozone NAAQS and the 1997 PM2.5 NAAQS. 

As part of this Consent Decree, the USEPA also committed to take action on the remaining 

SIP elements by March 17, 2008, for ozone and October 5, 2008, for PM2.5. 

 

3 Finding of Failure to Submit Section 110 State Implementation Plans for Interstate Transport for the National 

Ambient Air Quality Standards for 8-Hour Ozone and PM2.5, 70 FR 21147 (April 25, 2005). 
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NHDES FINAL March 2008 

Figure 2-1. Ozone Nonattainment Areas in New Hampshire 

STATE OF

NEW HAMPSHIRE

Ozone 

Nonattainment Areas

8-Hour Southeast New Hampshire 

Moderate Area

Former 1-Hour Serious 

Nonattainment Areas

Former 1-Hour 

Marginal

Nonattainment Areas

Attainment Areas

2/18/2008 1_8-hrBndys with Counties.gsm Pelham

Hudson

Nashua Hollis Brookline Mason New 

Ipswich

Rindge

Windham

Salem

Atkinson

Newton South

Hampton

Seabrook

Hampton

North

Hampton

Rye

Ports

mouth New Castle

Derry Hampstead

San

down Dan

Ville Kings

ton

East

Kings

ton

Kens

ington

Hamp

 ton

 Falls

Exeter

Strat

Brent ham

Fremont Wood

Epping Newmarket

Newfields Green

 land

Newing

ton

Durham

MadburyDover

Rollingsford

Sommersworth

Rochester

Barrington

Milton

Farmington

Strafford

Nottingham Lee

Northwood

Deerfield

Raymond

Candia

Auburn

Chester

London

Derry

Manchester

Hookset

Concord

Allens Bow town

Pembroke

Hopkinton

Weare

Goffstown

Bedford

AmherstMerrimack

Litchfield

New

Boston

Lynde

borough

Mt.

Vernon

Milford

Wilton

Temple

Dunbarton

Richmound Fitzwilliam

Winchester

Hinsdale

Chesterfield

West

moreland Keene

Swanzey

Troy Jaffrey

Marl Dublin

borough

Roxbury Harrisville

Peter

borough

Sharon

Greenland

Frances

town Hannock

Benning

ton

Deering

Antrim

Stoddard

Nelson

Sullivan

Gilsum

Surry

Walpole

Acworth Lempster

Langdon

Charles

town

Alstead

Marlow

Washington

Hillsborough

Henniker

Bradford

Warner

Newbury Goshen Unity

Claremont

Cornish

Plantfield

Lebanon

Hanover

Enfield

Enfield

Grantham

Croydon

Newport

Sunapee

Springfield

Grafton

Orange

Danbury

Alexandria

Wilmot

New

London

Sutton

Salibury

Andover

Hill

Bristol

Hebron

Bridge

water New

Hampton

Meredith

Sanbornton

Franklin

Northfield

Webster

Canterbury

Loudon

Epsom

Pittsfield

Gilmanton

Belmont Tilton

Laconia

Gilford

Alton

Barnstead

New

Durham

Brook

field

Middle

town

Wakefield

Wolfboro

Moulton

borough

Tuftonboro Ossipee

Lyme

Orford

Piermont

Haverhill

Bath

Warren

Benton

Wentworth

Dorchester

Groton

Rumney

Ellsworth

Woodstock

Lincoln

Easton

Landaff

Monroe

Lyman

Lisbon Sugar

Hill Franconia

Bethlehem

Littleton

Carroll

Livermore

Waterville

Valley

Thornton

Campton

Plymouth Holderness

Ashland

Sandwich

Hebron

Albany

Tamworth

Freedom

Effingham

Conway

Madison Eaton

Hebron

Jackson

Chatham

Beans

Purchase

Sargents

Purchase Crawfords 

Purchase

Low&Burbanks

Grant

Beans

Grant

Martins Loc.

Greens Grant

Pinkhams 

Grant

Hales

Location

Dalton Whitefield Jefferson

Lancaster

North

Umberland

Kilkenny

Randolph

Berlin

Gorham Shelburne

Sucess

Milan Stark

Stratford

Columbia

Colebrook

Stewartstown

Dixville

Millsfield

Odell

Dummer Cambridge

Errol

Wentworths

Location

Second

College 

Grant

Dixs

Grant

Atkinson & Gilmanton

Academy Grant

Clarksville

Pittburg

Ervings 

Location

COOS

GRAFTON

CARROLL

SULLIVAN

CHESHIRE

MERRIMACK

STRAFFORD

HILLSBOROUGH

ROCKINGHAM

BELKNAP
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NHDES FINAL March 2008 

Section 110(a)(2)(D)(i)(I) requires that each state’s SIP must contain provisions 

prohibiting sources in a State from contributing significantly to the nonattainment of another 

State or interfering with the maintenance in another State. In addition, Section 

110(a)(2)(D)(i)(II) requires that each state’s SIP must also contain provisions prohibiting 

emissions within the State from interfering with measures necessary to prevent significant 

deterioration of air quality or to protect visibility in another State. 

In March 2005, the USEPA promulgated the Clean Air Interstate Rule (CAIR). 4

 

Based upon the requirements of Section 110(a)(2)(D)(i), the USEPA determined in CAIR 

that nitrogen oxide (NOx) emissions from 25 States5

 and the District of Columbia (DC) 

contribute significantly to nonattainment and interfere with maintenance of the 8-hour ozone 

NAAQS in downwind states. In CAIR and a subsequent ruling6

 for Delaware and New 

Jersey, the USEPA determined that sulfur dioxide (SO2) and nitrogen oxide (NOx) emissions 

from 23 States7

 and DC contribute significantly to the nonattainment and interfere with 

maintenance of the 1997 PM2.5 NAAQS. New Hampshire was not included in CAIR as a 

state that contributes significantly to nonattainment nor interferes with maintenance of the 8-

hour ozone NAAQS and the 1997 PM2.5 NAAQS in downwind states. 

The 8-hour ozone NAAQS Implementation Rule8 and the 1997 PM NAAQS 

Implementation Rule9

 require States to develop and submit SIP revisions demonstrating 

attainment with the 8-hour ozone NAAQS and the 1997 PM2.5 NAAQS. The 8-hour ozone 

NAAQS attainment plans were due June 15, 2007, and the 1997 PM2.5 NAAQS attainment 

plans are due April 5, 2008. 

To demonstrate attainment, States must conduct air quality modeling. To fulfill this 

requirement, the member States10 of the Ozone Transport Commission (OTC) have been 

conducting air quality modeling. As part of CAIR, the USEPA also conducted air quality 

modeling as the basis for determining what states contribute to the transport of air pollution 

in downwind states and thus which states were to be included in CAIR. 

The USEPA guidance for this Transport SIP submittal says that states should submit 

technical information such as air quality modeling to support a negative declaration. NHDES 

 

4 Rule to Reduce Interstate Transport of Fine Particulate Matter and Ozone (Clean Air Interstate Rule); 

Revisions to Acid Rain Program; Revisions to the NOx SIP Call; Final Rule, 70 FR 25162 (May 12, 2005). 5

 Alabama, Arkansas, Connecticut, Florida, Delaware, Illinois, Indiana, Iowa, Kentucky, Louisiana, Maryland, 

Massachusetts, Michigan, Mississippi, Missouri, New York, New Jersey, North Carolina, Ohio, Pennsylvania, 

South Carolina, Tennessee, Virginia, West Virginia, and Wisconsin. 

6 Inclusion of Delaware and New Jersey in Clean Air Interstate Rule, 71 FR 25288 (April 28, 2006). 7

 Alabama, Florida, Delaware, Georgia, Illinois, Indiana, Iowa, Kentucky, Louisiana, Maryland, Michigan, 

Minnesota, Mississippi, Missouri, New York, New Jersey, North Carolina, Ohio, Pennsylvania, South Carolina, 

Tennessee, Texas, Virginia, West Virginia, and Wisconsin. 8 Final Rule to Implement the 8-hour Ozone National Ambient Air Quality Standard, 70 FR 71612 (November 

29, 2006). 

9 Clean Air Fine Particle Implementation Rule; Final Rule, 72 FR 20586 (April 25, 2007). 10 The Ozone Transport Region consists of Connecticut, Delaware, District of Columbia, Maine, Maryland, 

Massachusetts, New Hampshire, New Jersey, New York, Northern Virginia, Pennsylvania, Rhode Island, and 

Vermont. 
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NHDES FINAL March 2008 

will rely on the air quality modeling conducted for the OTC states for the attainment 

demonstration, modeling conducted by NHDES, as well as the USEPA’s modeling for 

CAIR. The OTC and NHDES modeling confirms the conclusions reached by the USEPA—

that New Hampshire does not contribute to nonattainment or maintenance in downwind 

states. 

NHDES adopted Prevention of Significant Deterioration (PSD) requirements (Env-A 

619) and New Source Review (NSR) regulations (Env-A 618) to help New Hampshire 

maintain and attain the NAAQS. These requirements also help prevent New Hampshire 

from contributing significantly to other states nonattainment and from interfering with the 

maintenance of air quality in other states. 

In regards to visibility and regional haze, the USEPA issued regulations in 1980 to 

address visibility and in 1999 to address regional haze. The 1980 regulations address 

reasonably attributable visibility impairment—that is, visibility impairment caused by 

emissions of air pollutants from one or a few sources. The 1999 regulations address regional 

haze—that is, visibility impairment caused by air emissions from numerous sources located 

over a wide geographic area. In accordance with the 1980 regulations, any new major source 

or major modification is required to assess visibility impacts as part of the permit application 

process. In the 1999 regional haze regulations, the USEPA found that all States contain 

sources that contribute to regional haze in at least one Class I area. Thus, States are required 

to submit a SIP by December 17, 2007 that addresses control measures for regional haze. 

States and Regional Planning Organizations (RPOs) are currently analyzing alternative 

strategies for addressing regional haze. 

3.0 Significant Contribution and Interference with 

Maintenance (Section 110(a)(2)(D)(i)(I)) 

Section 110(a)(2)(D)(i)(I) requires states to include provisions in the SIP that prohibit 

any source or other type of emissions activity from emitting air pollutants in amounts which 

contribute to nonattainment in another state or interfere with maintenance in another state for 

newly promulgated NAAQS, that is, for ozone and PM2.5. New Hampshire makes a 

negative declaration to certify that sources in the state do not significantly contribute to 

nonattainment in another state or interfere with maintenance in another state with 

respect to ozone and PM2.5. 

The basis for New Hampshire’s certification is the attainment status of downwind 

areas and air quality modeling results conducted by the USEPA, the OTC, and NHDES. In 

addition, the NHDES’ New Source Review and PSD regulations help to prevent sources 

from interfering with maintenance in downwind areas. Finally, NHDES has implemented 

reduction measures in the past, and will implement additional reduction measures in the 

future as specified in ozone and regional haze SIPs, if necessary, to help prevent sources 

from contributing to nonattainment in other states and from interfering with maintenance in 

other states. 
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NHDES FINAL March 2008 

3.1 Ozone and PM2.5 Attainment Status of Downwind Areas 

The primary basis for NHDES’ certification that New Hampshire sources do not 

contribute to nonattainment of the ozone and 1997 PM2.5 NAAQS in other areas is the fact 

that all of the areas downwind of New Hampshire are in attainment. Maine requested and 

was granted redesignation of the Portland, Maine ozone nonattainment area and the Midcoast 

Maine (Hancock, Knox, Lincoln, and Waldo Counties) ozone nonattainment areas to 

attainment in 2006. These areas have monitored attainment of the 8-hour ozone NAAQS 

based on the 3-year average of 2003 to 2005 and continuing through the summer of 2007. 

The rest of Maine was designated attainment for the 8-hour ozone standard. One downwind 

area in Massachusetts is designated as an 8-hour ozone nonattainment area. All areas 

downwind of New Hampshire are already designated as PM2.5 attainment areas. 

3.2 Air Quality Modeling 

For the purposes of its 8-hour ozone and the 24-hour and annual PM2.5 and regional 

haze modeling, New Hampshire relied on the regional photochemical air quality modeling 

that was done by the New York State Department of Environmental Conservation 

(NYSDEC), Northeast States for Coordinated Air Use Management (NESCAUM), and other 

modeling centers on the Community Multiscale Air Quality (CMAQ) and Regional 

Modeling System for Aerosols and Deposition (REMSAD) modeling platform. In addition, 

New Hampshire and other states used the CALGRID (California Photochemical Grid Model) 

screening-level modeling platform to evaluate additional emissions control scenarios and to 

perform sensitivity runs. The general methodologies that were used in running these 

modeling platforms are described in the sections below. 

3.2.1 Identification of Models and Domain Used 

As described above, the SIP-quality modeling that was done in support of New 

Hampshire and other states’ 8-hour ozone, PM2.5, and regional haze SIPs was performed on 

the CMAQ modeling platform. Additional modeling was done on the REMSAD and 

CALGRID screening-level platforms. The CMAQ and CALGRID platforms were run on the 

same modeling domain using a common set of model inputs. Specifically, the OTC ozone 

modeling domain was set up on a Lambert Conic Conformal projection and covers the 

eastern United States and parts of Canada. The southwest corner of the domain was set at 

264 km, -888 km and the northeast corner was set to 2328 km, 1176 km. A 12-km grid cell 

resolution was used with 172 grid cells in the east-west direction and 172 grid cells in the 

north-south direction. For the vertical grid definition, 22 layers were used in the CMAQ 

simulations. For CALGRID, processing programs were used to reformat the boundary 

conditions, meteorology, and emissions; these mapped the 22 layers used for CMAQ to a 

total of nine vertical layers for the CALGRID modeling. The OTC CMAQ/CALGRID 

modeling domain is shown in Figure 3-1. The OTC 12-km modeling domain is a subset of 

the 36-km national domain which was used by the RPOs for regional haze analysis. The 36-

km national grid is shown in Figure 3-2. 
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NHDES FINAL March 2008 

Figure 3-1. Map of the CMAQ/CALGRID Modeling Domain 

0 20 40 60 80 100 120 140 160

0

20

40

60

80

100

120

140

160
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NHDES FINAL March 2008 

Figure 3-2. Map of the RPO National Domain 

For the CMAQ modeling, boundary conditions were derived from GEOS-Chem 

(Goddard Earth Observing System) global atmospheric simulations by running CMAQ on 

the 36-km continental grid. For the CALGRID platform, initial conditions, side boundary 

conditions, and top layer concentrations were derived from the CMAQ boundary conditions 

files by means of a processing program. This program mapped the 22 vertical layers used in 

the CMAQ simulations to the nine layers used with CALGRID. It produced the necessary 

side boundary file and top layer concentration file for each modeled episode day. It also 

produced an initial conditions file for each episode day processed; these files could be 

retained so that the CALGRID user could begin a simulation on any desired episode day. It 

should be noted that the default option of using 2002 boundary conditions was employed for 

all of the base case and future year CMAQ and CALGRID simulations. 

Further details regarding the technical options used in the CMAQ simulations are 

available in NYSDEC’s technical support document TSD-1d, 8hr Ozone Modeling using the 

SMOKE/CMAQ system, February 1, 2006. Additional information on the CALGRID 

modeling platform can be found in NHDES’ Modeling Protocol for the OTC CALGRID 

Screening-Level Modeling Platform for the Evaluation of Ozone, May 23, 2007.
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NHDES FINAL March 2008 

3.2.2 Emissions Processing Methodology 

The RPOs and their contractors prepared a set of base year and future year emissions 

inventories for use in the regional photochemical air quality modeling for the 8-hour ozone 

attainment demonstration as well as for the analysis of particulate matter and regional haze. 

These emissions inventories became the basis of the modeling inventories that were 

processed for input into the CMAQ air quality model using the Sparse Matrix Operator 

Kernel Emissions (SMOKE) model. The SMOKE modeling was performed by New York 

State Department of Environmental Conservation (NYSDEC) and other modeling centers, 

including the Virginia Department of Environmental Quality (VADEQ) and Northeast States 

for Coordinated Air Use Management (NESCAUM). Emissions processing was done for the 

2002 Base Year, 2009 On The Books/On The Way (OTB/OTW), 2009 Beyond On The Way 

(BOTW), and 2012 BOTW modeling scenarios. Further details on the SMOKE processing 

that was done in support of the 8-hour ozone attainment demonstration are provided in 

NYSDEC’s technical support document TSD-1c, Emission Processing for the Revised 2002 

OTC Regional and Urban 12 km Base Case Simulations, September 19, 2006.

For the CALGRID modeling effort, the pre-merged SMOKE emissions files were 

obtained from the modeling centers and re-formatted for input into EMSPROC (Emissions 

Processor), the emissions pre-processor for the CALGRID modeling system. EMSPROC 

allows the CALGRID user to adjust emissions temporally, geographically, and by emissions 

category for control strategy analysis. The pre-merged SMOKE files that were obtained from 

the modeling centers were broken down into the biogenic, point, area, non-road, and on-road 

emissions categories. These files by component were then converted for use with 

EMSPROC, thus giving CALGRID users the flexibility to analyze a wide variety of 

emissions control strategies. QA/QC plots were generated during the re-formatting of the 

emissions data to ensure that an accurate modeling inventory was generated for the 

CALGRID platform. Example emissions QA/QC plots are shown in Figures 3-3 through 3-

6. 
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NHDES FINAL March 2008 

Figure 3-3. QA/QC Plot of Surface Source CO Emissions 

Figure 3-4. QA/QC Plot of Surface Source VOC Emissions 
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NHDES FINAL March 2008 

Figure 3-5. QA/QC Plot of Point Source NOx Emissions 

Figure 3-6. QA/QC Plot of Point Source SO2 Emissions 
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NHDES FINAL March 2008 

3.2.3 Summary of USEPA’s CAIR Modeling Results 

USEPA promulgated the Clean Air Interstate Rule (CAIR) on March 10, 2005. 

Under CAIR, 28 states across the eastern United States and the District of Columbia will 

make reductions in emissions of NOx and SO2. Similarly, USEPA issued the Clean Air 

Mercury Rule (CAMR) on March 15, 2005. CAMR will reduce mercury emissions from 

coal-fired power plants. 

USEPA performed a technical analysis in support of CAIR and CAMR, including air 

quality modeling to evaluate ozone and PM2.5. The air quality modeling done in support of 

the final CAIR is described in USEPA’s Technical Support Document for the Final Clean 

Air Interstate Rule, Air Quality Modeling, March 2005. The air quality modeling for ozone 

was performed with the Comprehensive Air Quality Model with Extensions (CAMx) version 

3.10 on a modeling domain covering much of the eastern United States. For PM2.5, visibility, 

and deposition, the air quality modeling was done with CMAQ version 4.3 on a domain 

encompassing the lower 48 states and parts of Canada and Mexico. For the ozone analysis, 

three summer 1995 meteorological episodes were used in the CAMx modeling. For PM2.5, 

visibility, and deposition, the CMAQ model was run for the entire year 2001. The analysis 

years and emissions scenarios that were assessed included the following: 

y 2001 Base Year 

y 2010 Base Case 

y 2015 Base Case 

y 2010 CAIR Controls 

y 2015 CAIR Controls 

y 2015 CAIR+BART 

y 2015 BART-only 

The 2010 and 2015 Base Cases reflect expected economic growth and the anticipated 

benefits associated with existing emissions control programs. 

The CAMx and CMAQ model predictions for ozone and PM2.5 were used in a relative 

manner. Weighted-average 1999-2003 design values were used as the basis of the observed 

8-hour ozone and annual average PM2.5 concentrations. Using this methodology, USEPA 

estimated maximum 8-hour ozone and annual PM2.5 design values for each future-year 

scenario for each county in the modeling domain with a monitor. Table 3-1 shows the 

maximum estimated future 8-hour ozone design values for New Hampshire, Maine, and 

Massachusetts. These results show that, even without the emissions benefits associated with 

CAIR, all New Hampshire counties were predicted to be in attainment for 8-hour ozone for 

the 2010 and 2015 analysis years. Further, the table shows that areas downwind of New 

Hampshire (i.e., Maine and Massachusetts) were also predicted to be in attainment for 8-hour 

ozone for 2010 and 2015, even without the benefits of CAIR. Similarly, Table 3-2 shows the 

maximum estimated future annual design values for PM2.5. All of the maximum estimated 

future design values were predicted in be in attainment for annual PM2.5 for New Hampshire 
Transport SIP Revision Page 13 

NHDES FINAL March 2008 

and its downwind areas. The technical support document for the final CAIR did not 

summarize estimated design values for 24-hour PM2.5, therefore they are not provided here. 

Table 3-1. Summary of CAIR Modeling Results for Ozone for New Hampshire, 

Maine, and Massachusetts (in ppb)

Estimated Maximum 8-hour Future Design 

Values 

State County 

1999 – 

2003 

Average 

Design 

Value 

2010 

Base 

2010 

CAIR 

2015 

Base 

2015 

CAIR 

Belknap 78.0 68.5 68.2 65.8 65.0 

Carroll 66.5 60.3 60.0 58.6 58.0 

Cheshire 73.7 65.2 64.9 63.1 62.0 

Hillsborough 85.0 76.7 76.6 74.1 73.9 

Merrimack 73.0 64.8 64.6 62.3 61.8 

Rockingham 82.7 75.2 75.1 73.3 72.9 

New Hampshire 

Strafford 77.3 69.2 69.1 66.8 66.5 

Cumberland 84.7 75.9 75.8 73.4 73.0 

Hancock 92.0 80.7 80.5 77.2 76.8 

Kennebec 77.7 68.1 68.0 65.3 64.9 

Knox 83.3 73.7 73.6 70.7 70.4 

Oxford 61.0 54.9 54.7 53.2 52.7 

Penobscot 83.0 72.8 72.6 70.0 69.5 

Maine 

York 89.0 80.3 80.2 78.0 77.6 

Barnstable 94.7 83.7 83.6 80.8 80.2 

Berkshire 87.0 76.3 76.1 73.6 73.2 

Bristol 92.7 83.1 83.0 80.3 80.0 

Essex 89.7 81.8 81.7 80.6 80.2 

Hampden 90.3 80.4 80.2 77.3 76.7 

Hampshire 87.3 78.2 78.0 75.4 74.9 

Middlesex 88.7 79.3 79.1 76.1 75.8 

Suffolk 88.0 78.3 78.1 75.2 74.9 

Massachusetts 

Worcester 85.3 76.1 76.0 73.3 72.9 

Note: Data taken from Appendix E of USEPA’s Technical Support Document for the Final 

Clean Air Interstate Rule, Air Quality Modeling, March 2005.
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NHDES FINAL March 2008 

Table 3-2. Summary of CAIR Modeling Results for Annual PM2.5 for New 

Hampshire, Maine, and Massachusetts (in micrograms per cubic meter) 

Estimated Maximum Annual Future 

Design Values 

State County 

1999 – 

2003 

Average 

Design 

Value 

2010 

Base 

2010 

CAIR 

2015 

Base 

2015 

CAIR 

Cheshire 11.81 11.04 10.39 10.85 10.11 

Coos 10.11 9.98 9.49 9.93 9.37 

Merrimack 9.96 9.22 8.67 9.11 8.49 

New Hampshire 

Sullivan 9.95 9.40 8.75 9.26 8.53 

Androscoggin 10.60 10.16 9.75 10.04 9.58 

Aroostook 11.16 11.41 11.11 11.38 11.04 

Cumberland 11.44 10.66 10.23 10.50 10.02 

Hancock 6.20 5.98 5.65 5.95 5.58 

Kennebec 10.55 10.21 9.81 10.12 9.67 

Oxford 10.29 10.23 9.74 10.15 9.60 

Penobscot 9.87 9.81 9.46 9.73 9.34 

Maine 

York 9.63 9.07 8.64 8.97 8.50 

Berkshire 12.40 11.68 10.93 11.49 10.66 

Hampden 13.80 12.81 12.10 12.59 11.79 

Plymouth 11.34 10.65 10.02 10.50 9.78 

Massachusetts 

Suffolk 12.81 12.05 11.48 11.80 11.15 

Note: Data taken from Appendix F of USEPA’s Technical Support Document for the Final 

Clean Air Interstate Rule, Air Quality Modeling, March 2005. 

3.2.4 Summary of OTC and NHDES Modeling Results 

Regional air quality modeling was performed to examine various emission control 

strategies and determine the most acceptable SIP strategy. As described earlier, the model 

results were used in a relative sense—the effects on future design values were evaluated by 

applying relative reduction factors (RRF) based on model output to base year monitored 

design values. This RRF design value approach recognizes that the regional models have 

innate uncertainties and that these uncertainties can be minimized if the model is used in a 

relative, rather than an absolute manner. To minimize the effects of seasonal fluctuations on 

design values, the base year design values that were used, in accordance with USEPA 

guidance, were calculated as the three-year average of monitored design values for the 

periods of 2000-2002, 2001-2003, and 2002-2004. 

Based upon USEPA guidance, the following monitoring/modeling attainment 

demonstration strategies have been developed: 

 The 2009 OTC On The Way/On the Books (2009 OTW/OTB) - SIP Strategy

 The 2009 OTC Beyond On The Way (2009 BOTW) - Contingency SIP Strategy 
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NHDES FINAL March 2008 

Estimated future year 8-hour ozone design values for each of the above strategies are 

shown to be below the NAAQS for all New Hampshire monitors and those monitors in 

downwind areas. Figure 3-7 shows the CMAQ predicted 2009 design values compared to 

actual 2002 design values. Table 3-3 summarizes the modeling results for monitors in New 

Hampshire and its downwind areas. The results in Table 3-3 indicate that all areas in New 

Hampshire and downwind are expected to be in attainment for 8-hour ozone. 

Figure 3-7. CMAQ SIP Quality Modeling Results for 2009 OTC OTB/OTW vs. 

2002 Design Value Factors 

OTR Domain 

 2002 Design Values 2009 Design Values
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NHDES FINAL March 2008 

Table 3-3. Modeling Summary of Monitors in New Hampshire and Downwind Areas (ppb) 

Predicted Future Design Values 

(DVF) 

AIRS ID Name 

Current 

Design 

Value (DVC) 

2009 OTB/OTW 

(CMAQ) 

2009 BOTW 

(CMAQ) 

330012004 Laconia 76.5 nc nc 

330031002 Conway 67 nc nc 

330050007 Keene 74.3 64 64 

330090008 Haverhill 70.3 nc nc 

330110020 Manchester 75.5 n/a n/a 

330111010 Nashua 86 74 74 

330115001 Peterborough 84 73 73 

330130007 Concord 74.7 nc nc 

330150012 Rye 83.5 72 72 

330150013 Brentwood 80 68 68 

330150015 Portsmouth 68 59 59 

330173002 Rochester 78.5 67 67 

330190003 Claremont 74.3 nc nc 

230090102 ANP Cadillac Mt. 91.7 79 79 

230312002 Kennebunkport 88.3 77 77 

230313002 Kittery 85.3 74 74 

230052003 Cape Elizabeth 84.3 73 73 

230130004 Port Clyde 83.7 73 72 

230090103 ANP McFarland 83.7 72 72 

230112005 Gardiner 78 68 67 

230090301 Castine 75 65 65 

230310038 West Buxton 75 64 64 

230173001 North Lovell 60.7 nc nc 

230194008 Holden Rider 79 nc nc 

250213003 Milton 91 83 82 

250092006 Lynn 90 82 82 

250010002 Truro 92 80 80 

250051002 Fairhaven 91 80 79 

250130008 Chicopee 92 80 80 

250250041 Boston (Long I.) 88.7 80 80 

250094004 Newbury 86 76 75 

250154002 Ware 86.3 75 75 

250171102 Stow 85.7 74 74 

250034002 Adams 83.3 73 73 

250130003 Agawam 83 72 72 

250270015 Worcester 84 72 72 

250250042 Boston (Harrison Ave.) 73 66 66 

250150103 Amherst 74.7 69 65 

250090005 Lawrence 70 61 61 

Notes: 1) An “nc” indicates that a future design value was not calculated because of the limitation of the relative reduction factor 

(RRF) methodology. 2) The Manchester monitor was not included in the CMAQ results; this is indicated by “n/a” in the table. 
Transport SIP Revision Page 17 

NHDES FINAL March 2008 

3.2.5 CALGRID Zero Out of New Hampshire 

 NHDES performed a screening-level CALGRID model run to evaluate the impacts of 

New Hampshire’s emissions on downwind areas. For this model run, all anthropogenic 

emissions in New Hampshire were turned off. In this manner, an assessment of the change in 

estimated future 8-hour ozone design values could be made for the hypothetical case in 

which New Hampshire had no emissions. Figure 3-8 shows the differences in maximum 

predicted 8-hour ozone concentrations between the 2009 OTB/OTW scenario and the Zero 

Out New Hampshire run. With New Hampshire’s emissions turned off, improvements in 8-

hour ozone concentrations (which are expressed as positive differences in the figure) can be 

seen in Maine and Massachusetts. Improvements of between 3 and 5 ppb occur along the 

Maine coast and in northeastern Massachusetts. Areas of less significant improvement (0.25 

to 3 ppb) extend into inland areas of Maine and Massachusetts. 

Table 3-4 shows the estimated future design values for monitors in New Hampshire, 

Maine, and Massachusetts for the 2009 OTB/OTW and Zero Out New Hampshire scenarios. 

For the most part, estimated future design values were less sensitive to the turning off of New 

Hampshire’s emissions than were the maximum predicted 8-hour ozone concentrations. In 

Maine, estimated future design values improved by 5 ppb at monitors in Gardiner and West 

Buxton. Estimated future design values at all other Maine monitors improved by 2 ppb or 

less. For monitors in Massachusetts, estimated future design values improved by 1 ppb or 

less. Even in New Hampshire, estimated future design values at most monitors improved by 

4 ppb or less. The exceptions to this were the monitors at Laconia, Manchester, and 

Concord; these monitors showed improvements of between 8 and 10 ppb. The CALGRID 

screening-level results for the Zero Out New Hampshire model run suggest that 8-hour ozone 

values in New Hampshire, Maine, and Massachusetts are strongly influenced by emissions 

from upwind areas. 
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NHDES FINAL March 2008 

Figure 3-8. Plot of the Maximum (Worst-case) Difference in Model Predicted 8-

Hour Ozone Concentrations Between 2009 OTB/OTW and Zero Out of New 

Hampshire 

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

-30.00

-20.00

-10.00

-5.00

-1.00

0.25

1.00

3.00

5.00

10.00

15.00

20.00

25.00

30.00

40.00

Ozone

Concentrations

(PPB)

NHDES 7/31/07

CALGRID 2.45 

Modeling Domain
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NHDES FINAL March 2008 

Table 3-4. CMAQ/CALGRID Screening Results for Zero Out New Hampshire Scenario (ppb) 

Predicted Future Design Values 

(DVF) 

AIRS ID Name 

Current 

Design 

Value 

(DVC) 

2009 OTB/OTW

(CMAQ) 

CALGRID 2009 

Predicted 

Difference 

330012004 Laconia 76.5 nc 8 

330031002 Conway 67 nc 3 

330050007 Keene 74.3 64 1 

330090008 Haverhill 70.3 nc 0 

330110020 Manchester 75.5 n/a 9 

330111010 Nashua 86 74 2 

330115001 Peterborough 84 73 4 

330130007 Concord 74.7 nc 10 

330150012 Rye 83.5 72 1 

330150013 Brentwood 80 68 3 

330150015 Portsmouth 68 59 0 

330173002 Rochester 78.5 67 2 

330190003 Claremont 74.3 nc 0 

230090102 ANP Cadillac Mt. 91.7 79 2 

230312002 Kennebunkport 88.3 77 1 

230313002 Kittery 85.3 74 0 

230052003 Cape Elizabeth 84.3 73 0 

230130004 Port Clyde 83.7 73 1 

230090103 ANP McFarland 83.7 72 2 

230112005 Gardiner 78 68 5 

230090301 Castine 75 65 1 

230310038 West Buxton 75 64 5 

230173001 North Lovell 60.7 nc 2 

230194008 Holden Rider 79 nc 0 

250213003 Milton 91 83 1 

250092006 Lynn 90 82 1 

250010002 Truro 92 80 0 

250051002 Fairhaven 91 80 0 

250130008 Chicopee 92 80 0 

250250041 Boston (Long I.) 88.7 80 0 

250094004 Newbury 86 76 1 

250154002 Ware 86.3 75 0 

250171102 Stow 85.7 74 0 

250034002 Adams 83.3 73 0 

250130003 Agawam 83 72 0 

250270015 Worcester 84 72 1 

250250042 Boston (Harrison Ave.) 73 66 0 

250150103 Amherst 74.7 69 0 

250090005 Lawrence 70 61 0 
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NHDES FINAL March 2008 

3.2.6 Monitoring Data and Back Trajectories 

To further support the CMAQ and CALGRID modeling, monitoring data and 

trajectory analyses reveal that New Hampshire does not significantly contribute to the 

attainment status of Maine and Massachusetts, the two states that lie downwind of New 

Hampshire during weather patterns typical of this region. 

Maine

Monitoring data from Maine over the last ten years illustrate that the maximum ozone 

design value has been steadily declining, and for the last two years, the maximum design 

value has stayed below the current 8-hour ozone NAAQS of 0.08 ppm. For these reasons, 

Maine submitted and was granted a redesignation request to remove the nonattainment status 

of the Portland and MidCoast 8-hour ozone nonattainment area. Historical monitoring data 

for Maine is illustrated in Figure 3-9. 

Furthermore, none of Maine’s historical maximum PM2.5 design values have 

exceeded the daily or annual standard. Thus, the entire state of Maine has been and currently 

remains in attainment of the PM2.5 NAAQS. 

Massachusetts

Table 3-5 presents a summary of the exceedances of the 8-hour ozone standard for 

monitors in Massachusetts for 2003 - 2005. A back trajectory analysis of these exceedances 

indicates that New Hampshire has not been a major contributor to ozone events in 

Massachusetts. Three-day back trajectories were run with the HYSPLIT (HYbrid SingleParticle Lagrangian Integrated Trajectory) model for selected sites in four regions of the 

state: central, northeastern, southeastern, and eastern (near Boston) Massachusetts. The 

ending times correspond to the hour of the 8-hour ozone exceedance at the site, and the 

ending locations are 100 meters above mean sea-level, approximately ground level. These 

back trajectories are shown below in Figures 3-10 to 3-13. 

These trajectories rarely pass through New Hampshire. Instead, they indicate source 

regions in the Midwest and along the eastern corridor, including major metropolitan areas 

such as New York City. Those trajectories that do pass through New Hampshire, such as 

several ending in the Boston area, originate in the Midwest and tend to pass through the 

southwestern corner of New Hampshire as opposed to the more densely population areas of 

south central and relatively low emission southeastern New Hampshire. Thus, these 

trajectories are clearly dominated by large-scale transport from more distant regions. With 

the exception of the Newbury site on the far northeastern corner of the state, even those 

exceedances occurring at Haverhill and Chelmsford, located just south of the New 

Hampshire border, involve air masses traveling up the coast. 
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NHDES FINAL March 2008 

Figure 3-9. Historical 8-Hour Ozone Monitoring Data for Maine
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NHDES FINAL March 2008 

Table 3-5. Summary of Monitored 8-Hour Ozone Exceedances in 

Massachusetts for 2003-2005 

Central MA

Date Site 8-Hr Conc (ppm) Hour (EST) 

6/25/2003 Chicopee 0.099 10 

6/27/2003 Chicopee 0.089 9 

6/27/2003 Worcester 0.089 9 

6/29/2003 Chicopee 0.093 11 

7/22/2004 Chicopee 0.093 10 

4/20/2005 Worcester 0.090 13 

6/8/2005 Chicopee 0.088 12 

6/9/2005 Chicopee 0.104 11 

6/9/2005 Worcester 0.085 12 

6/24/2005 Chicopee 0.085 12 

6/24/2005 Worcester 0.087 13 

6/25/2005 Chicopee 0.090 10 

6/25/2005 Worcester 0.092 14 

6/26/2005 Chicopee 0.095 9 

7/26/2005 Chicopee 0.090 13 

7/26/2005 Worcester 0.085 13 

8/8/2005 Chicopee 0.085 11 

8/12/2005 Chicopee 0.098 12 

Northeastern MA

Date Site 8-Hr Conc (ppm) Hour (EST) 

6/25/2003 Newbury 0.092 11 

6/27/2003 Newbury 0.099 10 

7/22/2004 Haverhill 0.091 10 

7/30/2004 Newbury 0.085 11 

6/25/2005 Chelmsford 0.085 16 

6/27/2005 Chelmsford 0.095 10 
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NHDES FINAL March 2008 

Table 3-5 (Continued) - Summary of Monitored 8-Hour Ozone Exceedances in 

Massachusetts for 2003-2005 

Southeastern MA

Date Site 8-Hr Conc (ppm) Hour (EST) 

6/25/2003 Fairhaven 0.098 12 

6/25/2003 Truro 0.094 10 

6/26/2003 Fairhaven 0.100 13 

6/27/2003 Fairhaven 0.117 5 

6/27/2003 Truro 0.110 9 

7/4/2003 Fairhaven 0.086 16 

7/4/2003 Truro 0.087 19 

7/5/2003 Fairhaven 0.094 11 

7/5/2003 Truro 0.094 13 

7/8/2003 Truro 0.088 11 

7/26/2003 Fairhaven 0.087 13 

7/26/2003 Truro 0.087 16 

8/16/2003 Fairhaven 0.101 12 

8/16/2003 Truro 0.089 12 

8/21/2003 Fairhaven 0.085 12 

8/21/2003 Truro 0.087 13 

5/11/2004 Truro 0.085 14 

6/8/2004 Truro 0.089 16 

6/9/2004 Fairhaven 0.099 13 

6/9/2004 Truro 0.107 13 

4/19/2005 Truro 0.088 19 

4/20/2005 Truro 0.088 13 

6/9/2005 Truro 0.087 8 

6/25/2005 Truro 0.088 12 

6/26/2005 Truro 0.087 10 

8/5/2005 Truro 0.094 10 

8/11/2005 Fairhaven 0.086 9 

8/11/2005 Truro 0.095 12 
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NHDES FINAL March 2008 

Table 3-5 (Continued) - Summary of Monitored 8-Hour Ozone Exceedances in 

Massachusetts for 2003-2005 

Eastern MA (Boston Area)

Date Site 8-Hr Conc (ppm) Hour (EST) 

6/25/2003 Lynn 0.088 9 

6/27/2003 Boston - Long Island 0.102 7 

6/27/2003 Lynn 0.100 9 

8/22/2003 Lynn 0.092 9 

6/8/2004 Boston - Long Island 0.094 16 

6/8/2004 Lynn 0.092 17 

7/30/2004 Lynn 0.088 10 

4/20/2005 Lynn 0.086 10 

6/24/2005 Boston - Long Island 0.086 14 

6/24/2005 Lynn 0.094 16 

6/25/2005 Boston - Long Island 0.095 16 

6/25/2005 Lynn 0.099 15 

6/26/2005 Boston - Long Island 0.091 9 

6/26/2005 Lynn 0.096 9 

7/22/2005 Lynn 0.085 11 

7/26/2005 Lynn 0.088 12 

7/27/2005 Boston - Long Island 0.085 9 

8/11/2005 Boston - Long Island 0.089 11,12 

The Newbury trajectories do not fit the general patterns described above, but 

notwithstanding this site’s proximity to southeastern New Hampshire, they also fail to imply 

significant contribution from New Hampshire emissions. Trajectory models have historically 

had problems accurately reproducing the complicated air flows, vertically and horizontally, 

along the New England sea coast. As a result, trajectory modeling analyses in this region can 

suffer and produce non-intuitive results. For instance, two of the three Newbury trajectories 

come predominately off the ocean; these occur on June 25th and 27th, 2003, days during 

which several other sites also exceeded the ozone standard despite very different trajectory 

paths. Most other sites in the state received westerly flow on the 25th and slow southwesterly 

flow on the 26th. These conditions point to a regional episode in which sea breezes may have 

drawn off-shore plumes derived from sources to the west and south into the coastal site at 

Newbury. 

The third Newbury trajectory does cross directly through New Hampshire, but the 

original HYSPLIT plot reveals that this air mass descended sharply from a maximum 

elevation near 3000 meters over the vicinity of Montreal. One other Massachusetts site, 

Lynn, also exceeded the standard on the same day (July 30, 2004), and its trajectory followed 

a similar profile, descending from a similarly high elevation after stalling briefly in Canada; 

yet the Lynn trajectory is shifted more to the west and barely hits the southwestern corner of 

New Hampshire. Comparison of these trajectories reveals that the elevated ozone 
Transport SIP Revision Page 25 

NHDES FINAL March 2008 

concentrations on this day came from air transported aloft from locations upwind of both 

Massachusetts and New Hampshire. 

Figure 3-10. HYSPLIT Back Trajectories for 8-Hour Ozone Exceedances 

Chicopee and Worcester, Massachusetts 2003-2005

Chicopee

Worcester

HYSPLIT Model, EDAS Meteorology

Three-Day Back Trajectories

Ending Elevation 100m AMSL

Figure 3-11. HYSPLIT Back Trajectories for 8-Hour Ozone Exceedances 

Newbury, Haverhill, and Chelmsford, Massachusetts 2003-2005 

Newbury

Haverhill

Chelmsford

HYSPLIT Model, EDAS Meteorology

Three-Day Back Trajectories

Ending Elevation 100m AMSL
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NHDES FINAL March 2008 

Figure 3-12. HYSPLIT Back Trajectories for 8-Hour Ozone Exceedances 

Fairhaven and Truro, Massachusetts 2003 - 2005 

Fairhaven

Truro

HYSPLIT Model, EDAS Meteorology

Three-Day Back Trajectories

Ending Elevation 100m AMSL

Figure 3-13. HYSPLIT Back Trajectories for 8-Hour Ozone Exceedances 

Boston (Long Island) and Lynn, Massachusetts 2003-2005 

Boston - Long Island

Lynn

HYSPLIT Model, EDAS Meteorology

Three-Day Back Trajectories

Ending Elevation 100m AMSL
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NHDES FINAL March 2008 

4.0 Prevention of Significant Deterioration and Protection 

of Visibility (Section 110(a)(2)(D)(i)(II)) 

Section 110(a)(2)(D)(i)(II) requires states to include provisions in the SIP that 

prohibit any source or other type of emissions activity from emitting air pollutants in 

amounts which will interfere with measures required to be included in the SIPs of another 

State to prevent significant deterioration and to protect visibility. NHDES confirms that no 

major sources in the state interfere with measures in the SIP to prevent significant 

deterioration and to protect visibility according to the 1980 visibility provisions. Because 

regional haze studies are only now underway, NHDES cannot make a determination at this 

time in regards to interference with measures to protect visibility in accordance with the 1999 

regional haze provisions, but NHDES plans to make such a determination in the Regional 

Haze SIP. 

NHDES confirms that major sources and major modifications in the state are subject 

to Prevention of Significant Deterioration (PSD) provisions in ozone and PM2.5 attainment 

areas, including Best Available Control Technology (BACT) requirements and to 

Nonattainment New Source Review in ozone nonattainment areas, including Lowest 

Achievable Emission Rate (LAER) and emission offset requirements. The PSD provisions 

are contained in Env-A 619, Prevention of Significant Deterioration of Air Quality Permit 

Requirements. 

In addition, New Hampshire is part of the Ozone Transport Region (OTR); therefore, 

NHDES also meets the additional NSR11 and PSD provisions required in the OTR, 

particularly the major source and major modification emission thresholds and offset ratios. 

The federal requirement for the emission threshold for major NOx sources in New 

Hampshire under the 8-hour ozone NAAQS is 100 tons per year (tpy) statewide because the 

minimum federal emission threshold in the OTR is 100 tpy and also is 100 tpy in a moderate 

8-hour ozone nonattainment area. The federal emission threshold for major volatile organic 

compound (VOC) sources under the 8-hour ozone NAAQS is 50 tpy statewide because the 

minimum federal emission threshold in the OTR is 50 tpy even though the federal emission 

threshold for moderate 8-hour ozone nonattainment areas is 100 tpy. 

NHDES is currently more stringent than the federal emission threshold requirements 

under the 8-hour ozone NAAQS because NHDES currently uses the emission thresholds that 

NHDES adopted for the 1-hour ozone NAAQS, which were more stringent than required at 

that time as well because the emission thresholds are implemented countywide even if only a 

partial county is designated as nonattainment for the 8-hour ozone NAAQS. The emission 

threshold for major sources for VOCs is 50 tpy statewide. For NOx, the major source 

emission threshold is 50 tpy in the 4 counties (Hillsborough, Merrimack, Rockingham, and 

 

11 NSR provisions are contained in Env-A 618, Additional Requirements in Non-Attainment Areas and the New 

Hampshire Portion of the Northeast Ozone Transport Region. 
Transport SIP Revision Page 28 

NHDES FINAL March 2008 

Stafford), designated in part or whole as nonattainment for the previous 1-hour ozone 

standard (current 8-hour ozone NAAQS) and 100 tpy elsewhere in the state. Note that for 

anti-backsliding purposes, New Hampshire must maintain the major source emissions 

thresholds established under the 1-hour ozone standard. See Table 4-1 for a comparison of 

current emission thresholds and current federal requirements. For PM2.5 (or PM10 or TSP), 

the major source emission threshold is 250 tpy or 100 tpy statewide depending upon the 

source category. 

Table 4-1. Major Source Emission Thresholds for Ozone Precursors 

Current Emission 

Threshold (tpy) 

1-Hour Ozone 

Required 

Emission 

Threshold 

(tpy) 

8-Hour Ozone 

Required 

Emission 

Threshold (tpy) 

OTR Required 

Emission 

Threshold (tpy) 

VOC 50 50 100 50 

NOx – 4 

Counties 

50 50 100 100 

NOx – Statewide 

(Except 4 

Counties) 

100 100 100 100 

For major modifications, the significant net emission increase level is 25 tpy for TSP 

and 15 tpy for PM10 and PM2.5, since New Hampshire is using the PM10 emission threshold 

and standard as a surrogate for PM2.5 until PM2.5 specific provisions are adopted. For VOCs, 

the significant net emission increase level for major modifications is 25 tpy in the 4-counties 

(Hillsborough, Merrimack, Rockingham, and Stafford) and 40 tpy elsewhere in the state. For 

NOx, the significant net emission increase level for major modifications is 25 tpy in the 4-

counties (Hillsborough, Merrimack, Rockingham, and Stafford) and 40 tpy elsewhere in the 

state. 

NHDES also has a special provision, Env-A 615, Interstate Air Quality Impacts, 

which currently states the following: 

The department shall apply special emission limits to a stationary source to 

ensure that its air quality impacts on adjacent states shall not interfere with 

the measures taken in those states to prevent significant deterioration of air 

quality and shall not prevent the attainment or maintenance of the NAAQS in 

those states. 

For these provisions, air quality dispersion modeling is used to determine significant 

deterioration. 

The PSD and NSR provisions for the 8-hour ozone and 1997 PM2.5 NAAQS and the 

Interstate Air Quality Impact provisions are measures to prevent major sources from 

contributing to significant deterioration of the 8-hour ozone and 1997 PM2.5 NAAQS. 
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NHDES FINAL March 2008 

If deemed necessary, NHDES will update the PSD/NSR provisions to meet the 8-

hour ozone NAAQS and 1997 PM2.5 NAAQS. In the meantime, NHDES uses the PSD and 

NSR regulations adopted to implement the 1-hour ozone NAAQS. These PSD and NSR 

provisions are equivalent to or more stringent than what would be required under the 8-hour 

ozone NAAQS.12 

In the future, if necessary, NHDES will revise its PSD regulations accordingly. In the 

meantime, New Hampshire uses the PM10 emission threshold and standard as a surrogate for 

PM2.5, per USEPA’s interim guidance. In addition, New Hampshire, in conjunction with 

other NESCAUM states, has developed PSD increment levels for air quality dispersion 

modeling purposes. 

In terms of visibility, NHDES implements the 1980 visibility provisions as part of the 

PSD/NSR permitting procedures; therefore, no major source or major modification can 

obtain a PSD/NSR permit unless it does not interfere with the 1980 visibility requirements. 

At this time, NHDES along with other States in MANE-VU and other RPOs are analyzing 

emissions and emission reduction strategies and formulating an approach for addressing the 

1999 regional haze provisions. In the regional haze SIP submittal due December 17, 2007, 

NHDES plans to discuss potential measures to address the 1999 regional haze requirements, 

if necessary. 

 

5.0 Administrative Materials 

On January 15, 2008, NHDES published in a statewide newspaper a public notice 

soliciting comment and announcing the opportunity for the public to request a public hearing 

for this SIP Revision. Appendix A includes a copy of the public notice of the comment 

period and request for a public hearing for this SIP revision. After the public comment period 

and public hearing, if requested, NHDES will document and review any comments received 

and provide a response, if necessary. NHDES will amend this SIP Revision, as necessary, 

and resubmit it with the additional documentation required to certify the SIP submittal. 

Appendices B and C will contain the comments received on this SIP revision and NHDES’ 

responses and the certification of the public hearing, if held. The Governor has designated 

the Director of the Air Resources Division as his designee per a copy of the letter included in 

Appendix D. 

 

 

12 Note that in December 2005, NHDES submitted a SIP revision with a preliminary draft of revisions to the 

PSD and NSR regulations. This revision was submitted in accordance with Parts C and D of Title I of the 

CAA. 
Appendix A 

Public Notice for SIP Revision 

Appendix B 

Public Comments and NHDES Response 


NH DES Responses to EPA’s Comments on New Hampshire’s 

Clean Air Act (CAA) Section 110(a)(2)(D)(i) 

State Implementation Plan (Transport SIP) 

Response to Comment #1: NH DES has revised the Transport SIP narrative to reflect the 

revised action date of March 17, 2008, for the Infrastructure SIP. 

Response to Comment #2: NH DES has revised Figure 2-1 to show Merrimack County as 

being designated marginal under the 1-hour ozone standard. 

Response to Comment #3: NH DES has revised the referenced section of the text to read as 

follows: “In Maine, estimated future design values improved by 5 ppb at monitors in 

Gardiner and West Buxton.” 

Response to Comment #4: NH DES has revised the referenced section of the text to read as 

follows: “For these reasons, Maine submitted and was granted a redesignation request to 

remove the nonattainment status of the Portland and MidCoast 8-hour ozone nonattainment 

areas.”
Appendix C 

Certification of Public Process 

Appendix D 

Evidence of Legal Authority