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New Hampshire Regional Haze SIP Revision 

Responses to AMC’s Comments 

On June 26, 2009, the New Hampshire Department of Environmental Services (NHDES) 

received comments from Georgia Murray, staff scientist from the Appalachian Mountain Club 

(AMC), on New Hampshire’s draft final Regional Haze SIP, May 22, 2009. Many of AMC’s 

comments supported the decisions and methodologies employed in development of the SIP and 

do not require a response. For specific comments that do need responses, NHDES provides the 

following. Comments are written in italics and responses are written in regular font.

MANE-VU Ask. AMC urges NH to include federally enforceable controls in its SIP to meet its 

commitment of a 90% reduction in SO2 emissions under the Targeted EGU Strategy. 

Preferably, NH should add a specific commitment to reduce SO2 emissions at NT1, a BARTeligible source, by 90%. NH should exhaust all possible options (fuel switching to natural gas, 

earlier use of 0.5%-S fuel oil, and/or an increase in enforceable reduction at Merrimack station 

to greater than 90%) to reduce the overall emissions for the 3 targeted stacks by 90%. AMC 

provides the following table to clarify the difference between the emission reduction targets 

from the MANE-VU Ask and the NH SIP. We recognize that NH and other states are provided 

some flexibility in meeting their regional haze obligations, and that NH has worked extensively 

to achieve the planned reductions included in this draft. However, it would be a missed 

opportunity to further improve NH air quality to not require 90% reduction of SO2 from each 

target EGU. Furthermore, the example put forth in NH’s RH SIP commitments will provide 

our state important leverage as we ask other states to control emissions that impact visibility in 

our Class I airsheds.

 NHDES Response: NHDES recognizes the need for enforceable control measures. 

Enforceable provisions for SO2 emission reductions are in place for Units MK1 and

MK2 and are in progress for Unit NT1. However, because of its low utilization rate 

and capacity factor, retrofitting Unit NT1 for flue gas desulfurization is not 

economically feasible. Consequently, the only practical means of reducing SO2

emissions at this plant is to control the sulfur content of fuels used. NHDES has 

prepared a draft rule that will limit SO2 emissions from Unit NT1 to 0.50 lb/MMBtu – 

a limitation that will require the operator to regulate and monitor fuel sulfur content. 

While this provision will not achieve the desired 90 percent SO2 reduction from this 

facility that was sought under the Ask, there are at least two mitigating circumstances 

to consider. First, the 90-percent reduction for Units MK1 and MK2 is a minimum. 

The actual reduction is expected to exceed this value; and, in fact, meeting the 
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maximum sustainable rate is a requirement of the facility’s draft Title V operating 

permit. Second, emissions from Unit NT1 have been trending lower since 2002 

because of the plant’s low usage. For example, reported SO2 emissions were 586 tons 

in 2008, a nearly 90 percent reduction from the 2002 base year. The combination of 

these circumstances is likely to put total SO2 emission reductions from the three units 

at or below the 90 percent target. 

New Hampshire, in concert with the other MANE-VU states and the Ozone Transport 

Commission, is contemplating further controls to reduce SO2 emissions across the 

region. One important initiative focuses on emission controls for industrial, commercial, 

and institutional boilers. NHDES is committed to a thorough reevaluation of the 167 

EGU strategy and related SO2 control measures as part of the regional haze 

midcourse review circa 2013 to ensure that New Hampshire is doing its part to 

achieve established visibility goals. 

Section 11.4.3. Table 11.1 The final column in this table appears to have incorrect values for 

NT1 2018 SO2 Emissions and the Total Emissions for 2018. 

 NHDES Response: The errors in the table have been corrected.

Section 11.8. Page 133 NH DES should clarify in this section, as they did in section 10.3, that 

the alternative method was used to calculate baseline and natural visibility. 

 NHDES Response: The following sentence has been added to the text pertaining to 

2000-2004 baseline and natural visibility values: “Note that both natural conditions 

and baseline visibility for the 5-year period were calculated in conformance with an 

alternative method recommended by the IMPROVE Steering Committee.” 

Page 134 The 3rd bullet states that the glide slope was “created by linear interpolation 

between the 20 percent worst visibility baseline value in 2004 and the 20 percent worst 

visibility value under natural conditions in 2064.” The glide slope should be based on linear 

interpolation between the average 20 percent worst visibility baseline value from 2000-2004 

and the 20 percent worst visibility value under natural conditions in 2064. It is difficult to read 

the values off the graph and determine what the actual glide slope is (in dv/year) and therefore 

difficult to determine what method was actually used by NH DES. The agency correctly refers 

to the baseline visibility average values (2000-2004) throughout the SIP, however it needs to 

clarify what was used to calculate the glide slope and what the actual rate of change is. 

 NHDES Response: The distinction regarding linear interpolation is noted and the 

text has been revised accordingly. Also, the following sentence has been added 

under the bullet for the glide slope (straight green line): “Visibility values used for 

the calculation of uniform rate of progress may be found in Table 10.1.”

Section 11.11. Page 140-141 NH DES discusses its obligation to ensure that control measures 

are federally enforceable to comply with the RHR requirements. Earlier in the SIP NH states 

that existing NOx and PM controls are considered BART; however, it is unclear that these 

controls will be federally enforceable with the information and attachments provided. This can 

be resolved by NH DES submitting as part of the RH SIP the appropriate Title V permits that 

provide federally enforceable requirements for operation of the SCR and ESP. While year 

round SCR is currently expected due to NOx RACT requirements, it is important to see the 
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permit documents that identify this. We recognize that NH does not have a merged 

construction and Title V permitting program, but the Temporary Permit referred to (TP-0008) 

does not identify enforcement of NOx and PM controls. 

 NHDES Response: PSNH Merrimack Station Units MK1 and MK2 will be subject 

to SO2, NOx, and PM emission limitations specified in its Title V operating permit 

(TV-0055; Attachment HH). Similarly, PSNH Newington Station Unit NT1 will be 

subject to SO2, NOx, and PM emission limitations specified in its Title V operating 

permit (TV-OP-054; Attachment II). Units MK2 and NT1 must also meet the 

enforceable BART provisions described in Tables 9-6 and 9-7, added to Section 9 of 

the SIP. These tables include references to proposed rulemaking Chapter Env-A 2300 

Mitigation of Regional Haze (Attachment GG). Also, stricter fuel sulfur standards 

developed as part of the MANE-VU Ask have been incorporated into proposed 

revisions to Env-A 1604 Sulfur Content Limitations for Liquid Fuels (Attachment FF).