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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

Region 

1 Congress Street, Suite 1100

BOSTON, MA 02114-2023

October 24 2008

Jeff Underhil

Air Resources Division

New Hampshire Deparment ofEnvironrental Services

29 Hazen Drive, PO Box 95

Concord, NH 03302-0095

Dear Mr. Underhil:

Previously, EP A received a preliminary draft of New Hampshire s Regional Haze State

Implementation Plan (SIP). EP A provided written comments on the preliminary draft to

New Hampshire in a letter dated July 10, 2008.

Subsequently, we received a revised version of New Hampshire s draft Regional Haze

SIP. We have reviewed the revised draft and found that New Hampshire has adequately

addressed most, but not all, of our previous comments. You wil find our comments on

the revised draft in the Enclosure.

If you have any questions on these comments, please contact Ane McWiliams of 

staff at 617-918- 1697.

Sincerely,

Ane Arold, Manager

Air Quality Planning Unit

Enclosure
Enclosure

EPA Comments on New Hampshire s Draft Regional Haze SIP (7118/08)

BART Determinations

As mentioned on page 81 , 40 CFR 51.308(e)(l)(A) states "The determination of BART

(Best Available Retrofit Technology) must be based on an analysis of the best system of

continuous emission control technology available and associated emission reductions

achievable for each BART-eligible source that is subject to BART within the State. 

this analysis, the State must take into consideration the technology available, the cost of

compliance; the energy and non-air quality environmental impacts of compliance, any

pollution control equipment in use at the source, the remaining useful life of the source

and the degree of improvement in visibility which may reasonably be anticipated to result

from the use of such technology.

Although NHDES referenced the MANE-VU five factor analysis of BART-eligible

sources for available control options and general analysis of the required factors

additional detail is needed specific to the New Hampshire BART sources, particularly in

the areas of expected visibility improvement and cost of compliance. This is especially

important in the case where NHDES is proposing a level of control less stringent than

that recommended by the MANE- VU BART workgroup.

Merrimack Station:

SOz

Under the "Available Retrofit Technologies for S02 Control " New Hampshire discusses

control via a wet flue gas desulphurization (FDG or "scrubber ) system. This discussion

indicates that FGD "can be designed to remove greater than 95 percent of incoming

S02." Therefore, NHDES should explain why New Hampshire is proposing a final

control level of only 90%.

Page 82, Footnote 17 - This footnote indicates that the New Hampshire Clean Powers

Act requires an 80% control level from the FGD. It further indicates that once the unit

demonstrates a sustainable control level greater than 80%, the requirement is raised to

that higher level. NHDES should expand on what is considered demonstrating a

sustainable control level and the anticipated timeframe for achieving this higher level of

control.

PMlO

The Appendix X discussion of the current control level in respect to PMlO for the

Merrimack unit lists the current control as electrostatic precipitators (ESP)s with a control

level of 85%. On page 84, Table 9.4

, 

PMIO Emission Reductions Resulting from

Application of BART Controls " lists the current control as 97% control. NHDES should
clarify whether 85% or 97% is the current level of control, and clearly state what level of

control has been determined to represent BART.

Newinflton Station:

SOz

Newington Station is one ofthe l67 stacks which impacts a Class 1 area as well as a

BART source. FGD would be expected to reduce S02 emissions by 95%, while New

Hampshire s proposal to require 1 % sulfur fuel would only achieve a 50% reduction. In

addition, the MANE-VU "ask" includes 0.5% sulfur fuel for the 167 stacks and 0.3%

sulfur fuel has been recommended as BART by the MAN-VU BART workgroup.

Therefore, it is not clear why New Hampshire has determined that a less stringent

requirement of 1 % sulfur fuel represents BART for this source. NHDES should include

an analysis of the feasibility of implementing these other control strategies at Newington

as well as a discussion of the visibility impacts of varous strategies, especially ifNHI?ES

determines that an option less strngent than the MANE-VU recommendations is BART.

PMlO

Appendix X indicates that Newington currently has a permitted daily cap of 0.

Ib/MMBtu and currently operates an ESP. Table 9.4

, 

PMlO Emission Reductions

Resulting from Application of BART controls " lists the current level of control (which is

proposed as BART) to be 56%. The MANE-VU BART workgroup recommendation for

non-CAIR EGUs, however, is 0. 02 - 0. 04Ib/MMBtu. Also, as stated in the available

retrofit technologies for PMlO control, rebuilt ESPs can achieve collection efficiencies of

more than 99%. Therefore, it is not clear why New Hampshire has determined that

curent controls, which are less stringent than the MANE- VU recommendation, are

suffcient for BART. NHDES should examine (and document) other options before

concluding that current controls are BART.

Enforceabilitv

Table 9.3 and 9.4 indicate that, for NOx and PM, respectively, "current controls (ESP

SCR, etc.) are BART. " It should be noted that BART requirements must be federally

enforceable. Therefore, the BART discussion should reference the specific existing

federally enforceable requirements that require these "current controls. " Alternatively, if

the requirements implementing the current controls are not yet federally enforceable, they

must be submitted to EP A as a SIP revision.

Section 9.4.2 Bart-Elieible EGUs and the role of CAIR

Massachusetts is classified as a seasonal CAIR state and should not be included in the list

ofNon-CAIR states.
Section 3. 2 Meetine the "Ask" - New Hampshire

Merrmack Station and Newington Station have both been identified as BART sources

and as two of the top 167 stacks contributing to visibility impairment in a MAN- VU

Class I area. The MANE- VU "Ask" requests that the l67 stacks be controlled to the 90%

level. This section of New Hampshire s SIP states that NHDES has determined that 90%

control is not reasonable for the Newington station at this time but that NHDES

anticipates that controls installed at the Merrmack station wil result in over-compliance

thereby partially offsetting the lesser control at Newington. According to the BART

determination, however, Merrmack station is only expected to be controlled at the 90%

level. NHDES should explain why 90% control of S02 at Newington is not reasonable

and why BART for S02 at Merrmack station is set at 90% if the level of control is

expected to be greater than 90%.

Section 11.9 New Hampshire s Share of Emission Reductions

In discussing New Hampshire s obligation to meet its share of emission reductions

NHDES references:

Emission controls on targeted in-state EGUs that contribute to visibility

impairment at Class I area in the region - more specifically, compliance with New

Hampshire law RSA l25- , Multiple Pollutant reduction Program, which

mandates the installation of scrubbers on PSNH Merrmack Station Units land 2

by July 1 , 2013, to control S02 and mercury emissions; these controls wil reduce

S02 emissions by a minimum of 80% from 2002 levels;

In the "meeting the ask" section, the control level of Merrmack station is stated to be in

excess of90%, while in the BART discussion it is expected to be 90%, and the discussion

above references 80%. NHDES should clarify what level of S02 control wil be required

and what mechanism is going to be used to make the S02 control federally enforceable.

In addition, this section discusses a low sulfur fuel strategy. What mechanism is New

Hampshire planning to use to make the low sulfu fuel strategy federally enforceable?