New Hampshire Revised Sulfur Dioxide Page 3 

Nonattainment Area Boundary Recommendation July 6, 2011

FIGURE 1. Proposed Central New Hampshire 1-Hour Sulfur Dioxide 

Nonattainment Area 

Central New Hampshire 

1-Hour SO2 Nonattainment Area

SO2 Monitor Exceeding 1-Hour NAAQS

SO2 Monitor Meeting the 1-Hour NAAQS

New Hampshire

Pe lham

H uds on

Na s hua Holli s B rook line M as on Ne w 

Ips wic h

R indge

W indha m

Sal em

A tk inson

Ne wton Sout h

Ha mpt on

Se abrook

Hampton

North

Ha mpton

Ry e

Port s

mout h Ne w C as tle

Ha mpst ea d D erry

San

dow n Da n

Vill e Ki ngs

t on

East

Kings

ton

Ke ns

ington

Ha mp

 ton

 Fall s

Exe te r

St ra t

B re nt ham Fre mont W oo d

Epping New mark et

New fi elds G ree n

 la nd

N ew ing

ton

Durha m

MadburyDov er

R ol lingsf ord

Sommers worth

R oc hes te r

Ba rri ngt on

Milt on

Fa rmi ngt on

Straf ford

N ott ingha m Lee

Nort hwood

De erfi eld

Ra ymond

Ca ndi a

Auburn

Ches te r

London

D erry

M anc he st er

H ook se t

Concord

A lle ns

t own Bow

Pe mbrok e

H opk inton

W ea re

Goff st own

B edford

A mhe rstMe rrima ck

Lit chf iel d

Ne w

Bos ton

Lynde

borough

Mt.

Ve rnon

Mi lford

Wilt on

Te mple

Dunba rton

Ri chmound Fit zw illi am

W inches te r

Hins da le

Ches te rfie ld

Wes t

more land Ke ene

Sw anz ey

Troy Ja ff re y

Marl Dublin

borough

Rox bury Harris vil le

Peter

borough

Sha ron

G ree nl and

Fra nce s

town Ha nnoc k

Be nning

ton

De ering

Ant ri m

Stodda rd

Ne lson Sulliv an

Gils um

Surry

Wal pole

Ac worth Le mpst er

Langdon

Charle s

town

A lst ea d M arlow

Was hingt on Hill sborough

He nnik er

Bradf ord

Wa rne r

N ew bury G os hen Unity

C laremont

Corni sh

Pl antf ie ld

Lebanon

H anove r

Enfie ld

Enf ie ld

Grant ha m

Croydon

Ne wport Sunape e

Springf ie ld

G ra ft on

Orange

Da nbury

Ale xa ndria

Wil mot

N ew

London

Sutt on

Sali bury

Andove r

H ill

Bris tol

H ebron

B ri dge

w at er Ne w

Ha mpt on M eredit h

Sanbornton

Frank lin

Northfi eld

W ebst er

C ant erbury

Loudon

Eps om

Pi tt sfiel d

G ilma nton

B el mont Til ton

Lac onia

Gi lford

Alton

Ba rns te ad

Ne w

Durham

Brook

fie ld

Middl e

tow n

W ak ef iel d

W ol fboro

M oul ton

borough

Tuft onboro O ss ipee

Ly me

Orford

Pie rmont

H av erhill

Ba th

Warren

B enton

Went worth

Dorches te r

G rot on

R umne y

Ells worth

W ood st o ck

Linc oln

Ea st on

Landa ff

Monroe

Ly man

Lisbon Suga r

Hil l Franconia

Bet hlehe m

Little ton

Ca rroll

Li vermore

Wa te rv ille

Val ley

Thornton

C ampton

Ply mout h Holde rne ss

As hl and

Sa ndw ic h

H ebron

A lbany

Ta mworth

Fre edom

Eff ingha m

Conwa y

Ma di son Eat on

He bron

Ja ck son

Cha tha m

Be ans

Purc has e

Sargents

Purc ha se Craw fords 

Purc has e

Low&B urbank s

Gra nt

Bea ns

Grant

Ma rtins Loc.

Gre ens Grant

Pink hams 

G ra nt

Ha les

Loc at ion

Dal ton

White fi eld Je ffers on

La nc as te r

North

Umbe rl and

K ilk enny

R andol ph

Be rlin

Gorham Shelburne

Suc es s

Mi lan Sta rk

Stra tford

C ol umbia

C ol ebrook

Ste wa rts town

Di xv ille

Mill sfield

Ode ll

Dummer Ca mbridge

Errol

Went worths

Location

Sec ond

Colle ge 

Grant

D ixs

G rant

A tk inson & Gil manton

A ca demy Gra nt

Cl arks vi lle

Pit tburg

Ervings 

Loc at ion
New Hampshire Revised Sulfur Dioxide Page 4 

Nonattainment Area Boundary Recommendation July 6, 2011
ATTACHMENT A

TECHNICAL ATTACHMENT 

Rationale for New Hampshire’s 1-Hour 

Sulfur Dioxide Nonattainment Area 

Boundaries 
New Hampshire Revised Sulfur Dioxide Page A-1 

Nonattainment Area Boundary Recommendation July 6, 2011

Rationale for New Hampshire’s 1-Hour Sulfur Dioxide 

Nonattainment Area Boundaries 

The recommendations contained in this letter are fully compliant with Section 107(d)(1)(A) of 

the Clean Air Act (“CAA”) which defines a nonattainment area as any area that (1) does not 

meet a National Ambient Air Quality Standard (“NAAQS”), or (2) contributes to ambient 

NAAQS violations in a nearby area. The New Hampshire recommended nonattainment area 

boundaries fulfill these requirements and exercises the flexibility allowed in the guidance, 

including consideration of: existing air quality, emission patterns, prevailing meteorology, 

topography and terrain, and jurisdictional boundaries. To a limited degree, airflow trajectories 

were also considered. 

The starting point of attainment area boundary designations is the examination of existing 

monitoring data. Table A1 contains the most recent 4 years of quality assured monitoring data 

for 1-hour average SO2 in New Hampshire. The locations of these monitors are marked in 

Figure 1 (above) and Figure A1 (below). 

TABLE A1. Estimated 2007 – 2010 1-Hour SO2 Design Values by Monitor, 

in parts per billion (ppb) 

Location Monitor 

ID 

2007 

98th

Percentile

2008 

98th

Percentile

2009 

98th

Percentile

2010 

98th

Percentile

2007-

2009 

Design 

Value 

2008-

2010 

Design 

Value 

SO2

NAAQS 

(ppb) 

Concord 33-013-1007 -- -- -- 46 -- 46 75 

Manchester 33-011-0020 58 48 50 57 52.0 51.7 75 

Pembroke 33-013-1006 165 141 222 217 176.0 193.3 75

Portsmouth 33-015-0014 59 62 42 45 54.3 49.7 75

State 

Maximum -- 165 141 222 217 176.0 193.3 75

All but one of the New Hampshire SO2 monitors indicate attainment of the new SO2 NAAQS. 

Monitors located in Manchester and Portsmouth have recent 3-year design values of about twothirds the level of the new NAAQS. A monitor located in Concord does not have 3 years’ worth 

of data, or even a full single year of data, but the 98th percentile of the data that does exist 

suggests that the monitor is likely to also meet the level of the new NAAQS. Only the Pembroke 

monitor fails to meet the level of the new SO2 NAAQS. This monitor is located about 0.4 miles 

to the southeast of a coal-fired power plant and is strategically located to capture the power 

plant’s worst-case air pollution impacts. 

The power plant, Merrimack Station, is subject to a state air pollution law that requires the 

installation of a scrubber system for the reduction of mercury emissions and SO2 emissions (as 

part of a Best Available Retrofit Technology (BART) requirement in the New Hampshire 

Regional Haze SIP). This scrubber system is under construction and is reportedly ahead of its 

construction schedule. Since the existing stacks for the station are relatively short, there is 

relatively poor dispersion of air pollutants. Part of the pollution control project includes 
New Hampshire Revised Sulfur Dioxide Page A-2 

Nonattainment Area Boundary Recommendation July 6, 2011

FIGURE A1. Presumptive Norm – Merrimack County Boundary 

SO2 Monitor Exceeding 1-Hour NAAQS

SO2 Monitor Meeting the 1-Hour NAAQS

New Hampshire

SO2 Monitors (2008-2010)

Merrimack

County

Pe lham

H uds on

Na s hua Holli s B rook line Mas on Ne w 

Ips wic h

R in dge

W indha m

Sal em

A tk in son

Ne wton Sout h

Ha mpt on

Se abrook

Hampton

North

Ha mpton

Ry e

Port s

mout h Ne w C as tle

Ha mpst ea d D erry

San

dow n Da n

Vill e Ki ngs

t on

East

Kings

ton

Ke ns

ington

Ha mp

 ton

 Fall s

Exe te r

St ra t

B re nt ham Fre mont W ood

Epping

New mark et

New fi elds G ree n

 la nd

N ew ing

ton

Durha m

MadburyDov er

R ol lingsf ord

Sommers worth

R oc hes te r

Ba rri ngton

Milt on

Fa rmi ngt on

Straf ford

N ott ingh a m Lee

Nort hwood

De erfi eld

Ra ymond

Ca ndi a

Auburn

Ches te r

London

D erry

Manc he ster

H oo k se t

Concord

A lle ns

t own Bow

Pe mbrok e

H opk into n

W ea re

Goffstown

B ed ford

A mhe rstM e rrima ck

Lit chf iel d

Ne w

Bos ton

Lynde

borough

Mt.

Ve rnon

Mi lford

Wilton

Te mple

Dunba rton

Ri chmound Fit zw illi am

W inches te r

Hins da le

Ches te rfie ld

Wes t

more land Ke ene

Sw anz ey

Troy Ja ffre y

Ma rl Dublin

borough

Rox bury Harris vil le

Pet er

borough

Sha ron

G ree nl and

Fra nce s

town Ha nnoc k

Be nning

ton

De ering Ant ri m Stodda rd

Ne lson

Sulliv an

Gils um

Surry

Wal pole

Ac worth Le mpst er

Langdon

Charle s

town

A lst ea d

Marlow

Was hingt on

Hill sborough

He nnik er

Bradford

Wa rne r

N ew bury G os hen Unity

C laremo nt

Corni sh

Pl antfie ld

Le banon

H anove r

Enfie ld

Enf ie ld

Grantha m

Croydon

Ne wport

Sunape e

Springf ie ld

G ra ft on

Orange

Da nbury

Ale xa ndria

Wil mot

N ew

London

Sutt on

Sali bury

Andove r

H ill

Bris tol

H ebron

B ri dge

w at er Ne w

Ha mpton

Meredit h

Sanbornton

Frank lin

Northfi eld

W eb st er

C an t erbury

Loudon

Eps om

Pi tt sf iel d

G ilma nton

B el mon t Til ton

Lac onia

Gi lford

Alt on

Ba rns te ad

Ne w

Durham

Brook

fie ld

M iddl e

tow n

W ak ef iel d

W ol fb oro

M oul ton

borough

Tuft onboro O ss ipee

Ly me

Orford

Pie rmont

H av erhill

Ba th

Warren

B ento n

Went worth

Dorches te r

G rot on

R umne y

Ells worth

W oodst ock

Linc oln

Ea st on

Landa ff

Monroe

Ly man

Lisbon

Suga r

Hil l Franconia

Bet hlehe m

Little ton

Ca rroll

Li ve rmore

Wa te rv ille

Val ley

Thornton

C ampton

Ply mout h

Holde rne ss

As hl and

Sa ndw ic h

H ebro n

A lb any

Ta mworth

Fre edom

Eff ingha m

Conwa y

M a di son Eat on

He bron

Ja ck son

Cha tha m

Be ans

Purc has e

Sargents

Purc ha se Craw fords 

Purc has e

Low&B urbank s

Gra nt

Bea ns

Grant

Ma rtins Loc .

Gre ens Grant

Pink hams 

G ra nt

Ha les

Loc at ion

Dal ton White fi eld Je ffers on

La nc as te r

North

Umbe rl and

K ilk en ny

R an dol ph

Be rlin

Gorham Shelburne

Suc es s

Mi lan Sta rk

Stra tford

C ol umbia

C ol eb roo k

Ste wa rts town

Di xv ille

Mill sfield

Ode ll

Dummer Ca mbridge

Errol

Went worths

Loc ation

Sec ond

Colle ge 

Grant

D ixs

G rant

A tk in son & Gil man ton

A ca demy Gra nt

Cl arks vi lle

Pit tburg

Ervings 

Loc at ion
New Hampshire Revised Sulfur Dioxide Page A-3 

Nonattainment Area Boundary Recommendation July 6, 2011

construction of a new Good Engineering Practice (GEP) stack for optimal dispersion. Stacks 

shorter than GEP allow for pollutant downwash, which brings air pollution down to the ground 

near the stack. The elimination of downwash combined with the benefits of SO2 emission 

reductions from the scrubber system should greatly diminish power plant SO2 impacts in the 

vicinity of the Pembroke monitor as soon as the new control system is operational. Once 

operation of this new system is required and a modeling demonstration shows compliance, the 

existing monitoring data for the Pembroke monitor showing nonattainment will be out of date 

and no longer representative of conditions in the vicinity of the power plant. EPA guidance 

suggests that if either monitoring data or dispersion modeling exceeds the NAAQS, the area 

should be defined as nonattainment. NHDES suggests that once the operation of the scrubber 

system becomes enforceable, the value of the modeling data should supersede the monitoring 

data. 

Evaluation of the Degree of Nonattainment in New Hampshire 

During pre-designation discussions between NHDES and EPA, EPA expressed concern that if 

New Hampshire followed the presumptive norm (county boundaries), portions of nearby 

counties may be excluded from the nonattainment area when there is likelihood that these areas 

could exceed the new SO2 NAAQS. Conversely, the presumptive norm boundaries would 

include the remote western portion of Merrimack County, which has a low likelihood of 

exceeding the SO2 standard. NHDES agrees that the presumptive norm boundary would present 

a nonattainment boundary that is off-centered and probably not a realistic estimate of estimated 

areas of concern. Through the flexibility allowed under the designation guidance, NHDES is 

providing the following information in order to improve on the presumptive norm boundaries 

and provide a more realistic estimate of SO2 nonattainment area boundaries. The discussion 

that follows is consistent with the five factors specified in Section 107(d)(1)(A) provisions of the 

Clean Air Act, and considers benefits likely to be achieved for the requirements. 

Five Factors for Evaluating Designation Boundaries

1. Air Quality data

2. Emissions-related data

3. Geography and topography

4. Meteorology and transport patterns

5. Jurisdictional boundaries (counties, existing nonattainment area boundaries, MPOs, etc.)

Central New Hampshire Nonattainment Area Discussion 

1. Air Quality Data

New Hampshire’s analyses starts with the identification of the EPA presumptive norm area for 

the county containing the Pembroke monitor (see Figure A1 above). The Pembroke monitor is 

indicated as a red dot while the Manchester and Portsmouth monitors, which are both meeting 

the new NAAQS are identified as green dots. 
New Hampshire Revised Sulfur Dioxide Page A-4 

Nonattainment Area Boundary Recommendation July 6, 2011

2. Emissions Related Data

Sulfur Dioxide emissions generally come from burning fossil fuels containing sulfur. Sulfur-rich 

fuels generally produce higher SO2 emissions. Fuels rich in sulfur include coal and oil 

compounds, but in each case the sulfur content varies depending on source and fuel processing or 

refining. In New Hampshire, the use of truly high sulfur coal or oil is rare. The sulfur content of 

fuel oils is on the decline and likely to continue decreasing in the future in order to continue 

progress towards air pollution and regional haze goals. For the most part, the sulfur content of 

fuel oil is not important to a unit that burns it. There is generally a higher cost for the fuel oil 

which can be off-set by lower cleaning to maintenance costs for maintaining optimal 

performance. 

On the other hand, the sulfur content of coal can matter to the unit combusting it, so simply 

requiring the use of low-sulfur coal to produce SO2 emission reductions may not be a viable 

control strategy. The point here is that a quick fuel switch may not always be a workable 

strategy. In the case of the power plant near the Pembroke monitor, coal switching to lower 

sulfur coals is unlikely to be a viable quick solution since many coals don’t burn efficiently in 

the boilers. Instead, the power plant is constructing a scrubber system to control its emissions, 

and that work is nearing completion. Since the plant currently burns a mix of low- and midsulfur coal, emissions of SO2 are lower than they could be, but the power plant is still a 

significant source of SO2. While there are other sources of SO2 in the area, they are consistent 

with emission levels throughout most of the remainder of the state, including areas near the 

Manchester and Portsmouth monitors which are both measuring levels well below the new SO2

NAAQS. There is no reason to believe that the Pembroke monitor would exceed the new SO2

NAAQS without the nearby proximity of Merrimack Station. 

3. Geography and Topography

The SO2 monitor located in Pembroke is located near the Merrimack River, which roughly runs 

from the north-northwest to the south-southeast in the area. The prevailing winds in the 

Pembroke area tend to flow in either direction up or down stream, following the river valley 

(Figure A2). For the most part, the land is rolling and hills reaching 1000 feet above sea level 

rise in almost every direction from the monitor. 

4. Meteorology and Transport Patterns

Following the logic that SO2 emissions from Merrimack Station play a major role in the SO2

monitoring values in Pembroke, then the dispersion patterns of those emissions can be estimated 

in order to form boundaries that reasonably capture areas likely to exceed the level of the new 

SO2 NAAQS. Ultimately, modeling will be performed to more precisely define these 

boundaries, but until this work is complete, estimated boundaries are being provided to 

extrapolate monitoring data values with dispersion assumptions. To start this work, prevailing 

wind patterns and terrain features were examined. In specific, terrain features with elevations 

near and above stable plume heights for Merrimack Station in each direction from the plant were 

identified. Stable plume heights of 783 to 1019 feet above seal level for the two boilers provide 

a target for terrain of similar elevation. In many cases, such terrain could be found within 10 
New Hampshire Revised Sulfur Dioxide Page A-5 

Nonattainment Area Boundary Recommendation July 6, 2011

miles of the power plant, and the goal was to include these locations in the current nonattainment 

designation recommendation. 

For lower level areas, a fairly simple measure was applied. The monitoring station in Concord is 

about 6 miles to the north of Merrimack Station and the Manchester monitor is located 10 miles 

to the south. Since both monitors currently show SO2 levels at about two-thirds the level of the 

NAAQS, this 10 mile distance was applied as a conservative ruler and all towns within about 10 

miles of Merrimack Station were included in the New Hampshire nonattainment boundary 

recommendations. The City of Manchester is the lone exception to this 10 mile rule, and it was 

excluded because it has 3-years of monitoring data showing compliance with the NAAQS. 

According to the presumptive norm presented by EPA designation guidance, the Central New 

Hampshire nonattainment area would extend westward into remote and upwind portions of 

Merrimack County. This western portion of the county would require east and southeast winds 

to carry power plant emissions up and over mountainous terrain before reaching the area. Wind 

roses for central New Hampshire (Figures A3 and A4) indicate that prevailing winds rarely blow 

in such a direction, five percent or less of the time per year. The most common wind directions 

are from the northwest or north-northwest (about 35% of the year) or from the south or southsoutheast (about 20% or the year). Such wind patterns suggest that there is a greater likelihood 

of elevated SO2 values to the southeast and the north of the Pembroke monitor, rather than the 

western portion of Merrimack County. Further, it should be noted that a band of terrain near 

1000 feet above sea level separate eastern Merrimack County from the western portion, forming 

a physical barrier protecting lower elevations beyond these mountains from SO2 emissions from 

Merrimack Station. The end result of this technical approach is that the recommended 

nonattainment area is better centered on Merrimack station than the presumptive norm 

boundaries would suggest and more consistent with prevailing wind patterns in the area (Figure 

A5). 

5. Jurisdictional Boundaries

The use of county boundaries appears to provide for an awkward nonattainment area boundary. 

While several physical boundary options are available, NHDES finds the traditional use of Town 

jurisdictional boundaries makes for effective boundaries for nonattainment areas in New 

Hampshire. Where physical or topographical features may be more scientific, NHDES will use 

those physical features and translate them to Town boundaries for designation recommendations. 

In summary, New Hampshire recommends that based on monitoring data and the application of 

dispersion science, a single nonattainment area should be designated in the south-central portion 

of the state near a large coal-fired power plant. NHDES recommends that this nonattainment 

area be named the Central New Hampshire SO2 Nonattainment Area. The remainder of the state 

should be designated as unclassifiable until the requisite dispersion modeling can be completed 

as according to EPA guidance, as requested in EPA’s guidance (and consistent with how 

designations are identified in Part 81 of the Code of Federal Regulations), 

attainment/nonattainment information is provided in Table A2. This information, along with 

digitized longitude and latitude coordinates for mapping purposes, and electronic versions of this 

data and associated maps will be provided. 
New Hampshire Revised Sulfur Dioxide Page A-6 

Nonattainment Area Boundary Recommendation July 6, 2011

Figure A2: Map of Bow Meteorology Station Demonstrating how Prevailing Wind 

 Patterns Follow Direction of the River 
New Hampshire Revised Sulfur Dioxide Page A-7 

Nonattainment Area Boundary Recommendation July 6, 2011

Figure A3: Wind Frequency Diagram for Bow New Hampshire 

Indicates percent of time the 

wind comes from a certain 

direction and with what speed
New Hampshire Revised Sulfur Dioxide Page A-8 

Nonattainment Area Boundary Recommendation July 6, 2011

Figure A4: Wind Frequency Diagram for Bow New Hampshire 
New Hampshire Revised Sulfur Dioxide Page A-9 

Nonattainment Area Boundary Recommendation July 6, 2011

TABLE A2. Proposed Designation of Areas for 1-Hour Sulfur Dioxide 

NAAQS Nonattainment in New Hampshire 

NEW HAMPSHIRE – SO2 (1-HOUR STANDARD) 

Designated Area Designation Classification 

Type Type 

New Hampshire: 

Hillsborough County 

 Goffstown Nonattainment -- 

 All remaining towns Unclassifiable -- 

Merrimack County 

 Allenstown Nonattainment -- 

 Bow Nonattainment -- 

 Chichester Nonattainment -- 

 Concord Nonattainment -- 

 Dunbarton Nonattainment -- 

 Epsom Nonattainment -- 

 Hooksett Nonattainment -- 

 Loudon Nonattainment -- 

 Pembroke Nonattainment -- 

 Pittsfield Nonattainment -- 

 All remaining towns Unclassifiable -- 

Rockingham County 

 Candia Nonattainment -- 

 Deerfield Nonattainment -- 

 Northwood Nonattainment -- 

 All remaining towns Unclassifiable -- 

All remaining counties Unclassifiable -- 
New Hampshire Revised Sulfur Dioxide Page A-10 

Nonattainment Area Boundary Recommendation July 6, 2011

TABLE A3. Towns in Presumptive Norm Boundaries of Merrimack 

 County that are Not Included in the Recommended 

 Nonattainment Area 

County 

 Town Notes** 

State Totals -- 

Merrimack 

County 

EPA Presumptive Norm for 1-Hour SO2 Nonattainment Boundaries 

 Andover More than 10 miles and beyond terrain of plume height elevation 

 Boscawen More than 10 miles and beyond terrain of plume height elevation

 Bradford More than 10 miles and beyond terrain of plume height elevation

 Canterbury More than 10 miles and beyond terrain of plume height elevation

 Danbury More than 10 miles and beyond terrain of plume height elevation

 Franklin More than 10 miles and beyond terrain of plume height elevation

 Henniker More than 10 miles and beyond terrain of plume height elevation

 Hopkinton More than 10 miles and beyond terrain of plume height elevation

 New London More than 10 miles and beyond terrain of plume height elevation

 Newbury More than 10 miles and beyond terrain of plume height elevation

 Northfield More than 10 miles and beyond terrain of plume height elevation

 Salisbury More than 10 miles and beyond terrain of plume height elevation

 Sutton More than 10 miles and beyond terrain of plume height elevation

 Warner More than 10 miles and beyond terrain of plume height elevation

 Webster More than 10 miles and beyond terrain of plume height elevation

 Wilmot More than 10 miles and beyond terrain of plume height elevation

TABLE A4. Towns Outside the Presumptive Norm Boundaries of 

Merrimack County that Are Included in the Recommended 

Nonattainment Area 

County 

 Town Notes** 

State Totals -- 

Hillsborough 

County 

 Goffstown First occurrence of plume height terrain within 10 miles - Uncanoonuc Mountains 

Rockingham 

County

 Candia Plume height terrain near areas that previous modeling indicated possible impact 

from Merrimack Station 

 Deerfield Plume height terrain near areas that previous modeling indicated possible impact 

from Merrimack Station

 Northwood Plume height terrain near areas that previous modeling indicated possible impact 

from Merrimack Station

 
New Hampshire Revised Sulfur Dioxide Page A-11 

Nonattainment Area Boundary Recommendation July 6, 2011

FIGURE A5. Comparison of Presumptive Norm Boundary with the New 

Hampshire Recommended Boundary 

Central New Hampshire 

1-Hour SO2 Nonattainment Area

SO2 Monitor Exceeding 1-Hour NAAQS

SO2 Monitor Meeting the 1-Hour NAAQS

New Hampshire

Merrimack

County

Pe lham

H uds on

Na s hua Holli s B rook line Mas on Ne w 

Ips wic h

R in dge

W indha m

Sal em

A tk in son

Ne wton Sout h

Ha mpt on

Se abrook

Hampton

North

Ha mpton

Ry e

Port s

mout h Ne w C as tle

Ha mpst ea d D erry

San

dow n Da n

Vill e Ki ngs

t on

East

Kings

ton

Ke ns

ington

Ha mp

 ton

 Fall s

Exe te r

St ra t

B re nt ham

Fre mont W ood

Epping

New mark et

New fi elds G ree n

 la nd

N ew ing

ton

Durha m

Madbury

Dov er

R ol lingsf ord

Sommers worth

R oc hes te r

Ba rri ngton

Milt on

Fa rmi ngt on

Straf ford

N ott ingh a m Lee

Nort hwood

De erfi eld

Ra ymond

Ca ndi a

Auburn

Ches te r

London

D erry

Manc he ster

H oo k se t

Concord

A lle ns

t own Bow

Pe mbrok e

H opk into n

W ea re

Goffstown

B ed ford

A mhe rstM e rrima ck

Lit chf iel d

Ne w

Bos ton

Lynde

borough

Mt. Ve rnon

Mi lford

Wilton

Te mple

Dunba rton

Ri chmound Fit zw illi am

W inches te r

Hins da le

Ches te rfie ld

Wes t

more land Ke ene

Sw anz ey

Troy Ja ffre y

Ma rl Dublin

borough

Rox bury Harris vil le

Pet er

borough

Sha ron

G ree nl and

Fra nce s

town Ha nnoc k

Be nning

ton

De ering Ant ri m Stodda rd

Ne lson

Sulliv an

Gils um

Surry

Wal pole

Ac worth Le mpst er

Langdon

Charle s

town

A lst ea d

Marlow

Was hingt on

Hill sborough

He nnik er

Bradford

Wa rne r

N ew bury G os hen Unity

C laremo nt

Corni sh

Pl antfie ld

Le banon

H anove r

Enfie ld

Enf ie ld

Grantha m

Croydon

Ne wport Sunape e

Springf ie ld

G ra ft on

Orange

Da nbury

Ale xa ndria

Wil mot

N ew

London

Sutt on

Sali bury

Andove r

H ill

Bris tol

H ebron

B ri dge

w at er Ne w

Ha mpton Meredit h

Sanbornton

Frank lin

Northfi eld

W eb st er

C an t erbury

Loudon

Eps om

Pi tt sf iel d

G ilma nton

B el mon t Til ton

Lac onia

Gi lford

Alt on

Ba rns te ad

Ne w

Durham

Brook

fie ld

M iddl e

tow n

W ak ef iel d

W ol fb oro

M oul ton

borough

Tuft onboro O ss ipee

Ly me

Orford

Pie rmont

H av erhill

Ba th

Warren

B ento n

Went worth

Dorches te r

G rot on

R umne y

Ells worth

W oodst ock

Linc oln

Ea st on

Landa ff

Monroe

Ly man

Lisbon Suga r

Hil l Franconia

Bet hlehe m

Little ton

Ca rroll

Li ve rmore

Wa te rv ille

Val ley

Thornton

C ampton

Ply mout h Holde rne ss

As hl and

Sa ndw ic h

H ebro n

A lb any

Ta mworth

Fre edom

Eff ingha m

Conwa y

M a di son Eat on

He bron

Ja ck son

Cha tha m

Be ans

Purc has e

Sargents

Purc ha se Craw fords 

Purc has e

Low&B urbank s

Gra nt

Bea ns

Grant

Ma rtins Loc .

Gre ens Grant

Pink hams 

G ra nt

Ha les

Loc at ion

Dal ton

White fi eld Je ffers on

La nc as te r

North

Umbe rl and

K ilk en ny

R an dol ph

Be rlin

Gorham Shelburne

Suc es s

Mi lan Sta rk

Stra tford

C ol umbia

C ol eb roo k

Ste wa rts town

Di xv ille

Mill sfield

Ode ll

Dummer Ca mbridge

Errol

Went worths

Loc ation

Sec ond

Colle ge 

Grant

D ixs

G rant

A tk in son & Gil man ton

A ca demy Gra nt

Cl arks vi lle

Pit tburg

Ervings 

Loc at ion
New Hampshire Revised Sulfur Dioxide Page A-12 

Nonattainment Area Boundary Recommendation July 6, 2011

Areas of Influence

In accordance with EPA guidance, New Hampshire has investigated the influence of New 

Hampshire emissions on 1-hour SO2 attainment/nonattainment within and beyond the state’s 

borders. Based on data currently available, there is no indication of a New Hampshire SO2

source causing or contributing to monitored nonattainment outside of the Central New 

Hampshire area. All monitors in northern New England are meeting the new SO2 NAAQS 

during the three most recent available monitoring years (2008-2010); however, this in itself does 

not ensure attainment until dispersion modeling is completed. Contributions of New Hampshire 

sources will be reassessed with modeling as required by EPA guidance. Until this new work is 

complete, New Hampshire recommends designation of unclassifiable for such cases.