Document ID: EPA-R01-OAR-2019-0352-0001
Agency: epa
Document Type: Proposed Rule
Title: Air Quality State Implementation Plans; Approvals and Promulgations: New Hampshire; Redesignation of the Central New Hampshire Sulfur Dioxide Nonattainment Area
Posted Date: 2019-07-31T04:00Z

[Federal Register Volume 84, Number 147 (Wednesday, July 31, 2019)]
[Proposed Rules]
[Pages 37187-37193]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-16271]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[EPA-R01-OAR-2019-0352; FRL-9997-35-Region 1]

Air Plan Approval and Air Quality Designation; New Hampshire; 
Redesignation of the Central New Hampshire Sulfur Dioxide Nonattainment 
Area

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
approve the maintenance plan and redesignation request submitted by the 
State of New Hampshire for the Central New Hampshire nonattainment area 
for the 2010 1-hour sulfur dioxide (SO2) national ambient 
air quality standard (NAAQS). This nonattainment area consists of 
portions of Hillsborough County, Merrimack County, and Rockingham 
County, New Hampshire. The primary emission source in the nonattainment 
area is now subject to federally-enforceable emission control 
standards, and air quality in the area now meets the 2010 
SO2 NAAQS. This action is being taken under the Clean Air 
Act.

DATES: Written comments must be received on or before August 30, 2019.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R01-
OAR-2019-0352 at https://www.regulations.gov, or via email to 
biton.leiran@epa.gov. For comments submitted at Regulations.gov, follow 
the online instructions for submitting comments. Once submitted, 
comments cannot be edited or removed from Regulations.gov. For either 
manner of submission, EPA may publish any comment received to its 
public docket. Do not submit electronically any information you 
consider to be Confidential Business Information (CBI) or other 
information whose disclosure is restricted by statute. Multimedia 
submissions (audio, video, etc.) must be accompanied by a written 
comment. The written comment is considered the official comment and 
should include discussion of all points you wish to make. EPA will 
generally not consider comments or comment contents located outside of 
the primary submission (i.e., on the web, cloud, or other file sharing 
system). For additional submission methods, please contact the person 
identified in the For Further Information Contact section. For the full 
EPA public comment policy, information about CBI or multimedia 
submissions, and general guidance on making effective comments, please 
visit http://www.epa.gov/dockets/commenting-epa-dockets. Publicly 
available docket materials are available at https://www.regulations.gov 
or at the U.S. Environmental Protection Agency, EPA Region 1 Regional 
Office, Air and Radiation Division, 5 Post Office Square--Suite 100, 
Boston, MA. EPA requests that if at all possible, you contact the 
contact listed in the FOR FURTHER INFORMATION CONTACT section to 
schedule your inspection. The Regional Office's official hours of 
business are Monday through Friday, 8:30 a.m. to 4:30 p.m., excluding 
legal holidays.

FOR FURTHER INFORMATION CONTACT: Leiran Biton, Air Permits, Toxics, and 
Indoor Programs Branch, U.S. Environmental Protection Agency, EPA 
Region 1, 5 Post Office Square--Suite 100, (Mail code 05-2), Boston, MA 
02109-3912, tel. (617) 918-1267, email biton.leiran@epa.gov.

SUPPLEMENTARY INFORMATION: Throughout this document whenever ``we,'' 
``us,'' or ``our'' is used, we mean EPA.

Table of Contents

I. Background and Purpose
II. Redesignation Requirements
III. Determination of Attainment
IV. New Hampshire's Approved State Implementation Plan
V. Permanent and Enforceable Emission Reductions
VI. Requirements for the Area Under Section 110 and Part D
VII. Maintenance Plan
VIII. Proposed Action
IX. Statutory and Executive Order Reviews

I. Background and Purpose

    On June 2, 2010 (75 FR 35520, June 22, 2010), EPA promulgated a new 
1-hour primary SO2 NAAQS of 75 parts per billion (ppb), 
which is met at an ambient air quality monitoring site when the 3-year 
average of the annual 99th percentile of daily maximum 1-hour 
concentrations does not exceed 75 ppb, as determined in accordance with 
appendix T of 40 CFR part 50. On August 5, 2013 (78 FR 47191), EPA 
designated a first set of 29 areas of the country as nonattainment for 
the 2010 SO2 NAAQS, including the Central New Hampshire 
nonattainment area within the State of New Hampshire. These ``round 
one'' area designations were effective October 4, 2013. In that action, 
the Central New Hampshire area was designated nonattainment for the 
SO2 NAAQS based on data collected at the Pembroke, New 
Hampshire ambient air quality monitoring station in calendar years 2009 
through 2011. The Central New Hampshire nonattainment area is comprised 
of 14 municipalities in portions of three different counties in New 
Hampshire. These cities and towns, and the counties in which they are 
located, are listed in Table 1. All other areas in the State were 
designated as attainment/unclassifiable for the 2010 SO2 
NAAQS in the ``round 3'' area designations on January 9, 2018. The 
Central New Hampshire nonattainment area contains the electric 
generating source Merrimack Station, currently owned and operated by 
GSP Merrimack

[[Page 37188]]

LLC and formerly by Public Service of New Hampshire (PSNH) d/b/a 
Eversource Energy, in Bow, New Hampshire, to which the State attributed 
about 90% of SO2 emissions contributing to the nonattainment 
designation.

    Table 1--List of Counties and Municipalities Included Within the Central New Hampshire Nonattainment Area
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                          County                                                Municipality
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Hillsborough County (part)................................  Goffstown Town.
Merrimack County (part)...................................  Allenstown Town, Bow Town, Chichester Town,
                                                             Dunbarton Town, Epsom Town, Hooksett Town, Loudon
                                                             Town, Pembroke Town, Pittsfield Town, City of
                                                             Concord.
Rockingham County (part)..................................  Candia Town, Deerfield Town, Northwood Town.
----------------------------------------------------------------------------------------------------------------

    By April 4, 2015, New Hampshire was required to submit a 
nonattainment plan State Implementation Plan (SIP) that meets the 
requirements of sections 172(c) and 191-192 of the CAA, and that would 
provide for attainment of the NAAQS as expeditiously as practicable, 
but no later than October 4, 2018. On March 18, 2016 (81 FR 14736), EPA 
found for a number of areas, including the Central New Hampshire area, 
that the states in which those areas are located had failed to submit 
the required SO2 nonattainment plan by the submittal 
deadline. In response to the requirement for SO2 
nonattainment plan submittals, New Hampshire submitted a nonattainment 
area plan and attainment demonstration for the Central New Hampshire 
nonattainment area on January 31, 2017.
    New Hampshire's submittal included new SO2 emissions 
limits and associated control technology efficiency requirements for 
Merrimack Station. In 2011, Merrimack Station installed and began 
operation of a flue gas desulfurization (FGD) scrubber system that is 
efficient in removing SO2 from the exhaust gas stream. On 
September 1, 2016, the State established permit conditions that include 
stringent emissions limits and prohibit operation of either of 
Merrimack Station's two coal-fired boilers when the FGD scrubber system 
is not operating except as necessary to prevent severe damage to 
equipment or potential injury to facility personnel.
    On June 5, 2018, EPA found that the emissions limits established by 
New Hampshire for Merrimack Station and submitted to EPA on January 31, 
2017 provide for attainment of the NAAQS, and EPA approved the limits 
and associated conditions into the New Hampshire SIP (83 FR 25922).
    Emissions from Merrimack Station have declined considerably in 
recent years. In 2010, Merrimack Station emitted 33,248 tons of 
SO2. Based on data the State presented from the 2014 
National Emissions Inventory (NEI), the total point, area, and mobile 
source SO2 emissions in the entire Central New Hampshire 
nonattainment area in 2014 were 1,481 tons per year (tpy), with 1,044 
tons (70.5%) emitted from Merrimack Station. In 2016, SO2 
emissions reported for Merrimack Station were 228 tons. Because of the 
significant, permanent, and enforceable reduction in SO2 
emissions affecting the nonattainment area, the (then) proposed 
approval of the State's nonattainment area plan and attainment 
demonstration, and the fact that the Pembroke SO2 monitor's 
three-year SO2 design value (DV) \1\ was below the 
SO2 NAAQS for 2012-2014 and 2014-2016, New Hampshire 
submitted a redesignation request in 2018.
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    \1\ The DV is a statistic computed according to the data 
handling procedures of the NAAQS (in 40 CFR part 50 appendix T) 
that, by comparison to the level of the NAAQS, indicates whether the 
area is violating the NAAQS. For SO2, the DV is the 
three-year average of the annual 99th percentile of one-hour daily 
maximum concentrations.
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    On March 16, 2018, the New Hampshire Department of Environmental 
Services (NHDES) submitted its request to EPA to redesignate the 
Central New Hampshire nonattainment area to attainment. The title of 
the submittal is ``1-Hour Sulfur Dioxide (2010 Standard) Redesignation 
Request and Maintenance Plan for the Central New Hampshire 
Nonattainment Area'' (New Hampshire's March 16, 2018 submittal). For 
the reasons set forth in this document, EPA is proposing to approve New 
Hampshire's request to redesignate the area to attainment.

II. Redesignation Requirements

    Under CAA section 107(d)(3)(E), there are five criteria which must 
be met before a nonattainment area may be redesignated to attainment.
    1. EPA has determined that the relevant NAAQS has been attained in 
the area.
    2. The applicable implementation plan has been fully approved by 
EPA under section 110(k).
    3. EPA has determined that improvement in air quality is due to 
permanent and enforceable reductions in emissions resulting from the 
SIP, Federal regulations, and other permanent and enforceable 
reductions.
    4. EPA has fully approved a maintenance plan, including a 
contingency plan, for the area under section 175A of the CAA.
    5. The State has met all applicable requirements for the area under 
section 110 and part D.
    Sections III (Determination of Attainment), IV (New Hampshire's 
Approved State Implementation Plan), V (Permanent and Enforceable 
Emission Reductions), VI (Requirements for the Area Under Section 110 
and Part D) and VII (Maintenance Plan) of this notice describe how New 
Hampshire meets each of these criteria for the Central New Hampshire 
nonattainment area.

III. Determination of Attainment

    As stated in the April 23, 2014 ``Guidance for 1-Hour 
SO2 Nonattainment Area SIP Submissions,'' (EPA's April 23, 
2014 Guidance) for SO2, there are two components needed to 
support an attainment determination: (1) A review of representative air 
quality monitoring data, and (2) a further analysis, generally 
requiring air quality modeling, to demonstrate that the entire area is 
attaining the applicable standard, based on current actual emissions or 
the fully implemented control strategy. New Hampshire has addressed 
both components, as described in the two following sections III.A and 
III.B.

A. Air Quality Monitoring Data

    The first requirement for redesignation is to demonstrate that the 
standard has been attained in the area. Under EPA regulations at 40 CFR 
50.17, the SO2 standard is met at an ambient air quality 
monitoring site when the three-year average of the annual 99th 
percentile of one-hour daily maximum concentrations is less than or 
equal to 75 ppb, as determined in accordance with appendix T of 40 CFR 
part 50 at all relevant monitoring sites in the subject area. EPA has 
reviewed the

[[Page 37189]]

ambient air monitoring data for the Central New Hampshire nonattainment 
area. The Central New Hampshire nonattainment area has two 
SO2 monitoring sites: One located in Concord at Hazen Drive 
(Site ID #33-013-1007) \2\ and one in Pembroke (Site ID #33-013-1006). 
The annual 99th percentile daily maximum SO2 concentrations 
were higher at the Pembroke monitor than the Concord monitor for all 
years reviewed by EPA (2012 through 2017). In New Hampshire's March 16, 
2018 submittal, the State demonstrated that the vast majority of 
monitored exceedances at the Pembroke monitor during the 2009-2011 
period occurred when wind directions were from Merrimack Station and 
toward the monitor. EPA's review of monitored air quality includes 
ambient data collected in the 2012-2014 period through the 2014-2016 
period, as well as data collected in the 2015-2017 period, which were 
the most recent quality-assured data available at the time of EPA's 
review. All data considered are complete, quality-assured, certified, 
and recorded in EPA's Air Quality System (AQS) database.
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    \2\ The Concord monitor ceased collection of SO2 
monitoring data at the end of 2016 due to low concentrations 
measured at that location.
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    Table 2 shows the three-year DVs for the periods between 2012 and 
2017 for the Central New Hampshire nonattainment area. For 2012, the 
last year during which emissions from Merrimack Station bypassed the 
FGD system (a practice that is no longer permitted except as necessary 
to prevent severe damage to equipment or potential injury to facility 
personnel under the State's September 1, 2016 permit), the 99th 
percentile monitored daily maximum value at the Pembroke monitor was 
26.9 ppb. For 2017, the first full year during which Merrimack Station 
was no longer permitted to operate unless its FGD system was operating, 
the 99th percentile daily maximum value at the Pembroke monitor was 
16.4 ppb. Within the Central New Hampshire nonattainment area, the 
maximum monitored three-year average DV for 2012-2014 was 23 ppb (31.7% 
of the NAAQS), and the three-year average DV for 2015-2017 was 15 ppb 
(20.0% of the NAAQS). Both values are low and show attainment with the 
SO2 standard. Therefore, the SO2 monitors in the 
Central New Hampshire area clearly show attainment. New Hampshire plans 
to continue monitoring for SO2 at the Pembroke location. 
Preliminary data for 2018 (January 1 through September 30) indicate a 
99th percentile monitored daily maximum value of 11.9 ppb at the 
Pembroke monitor, indicating that the area is continuing to attain the 
SO2 standard.

                             Table 2--Monitoring Data for the Central New Hampshire Nonattainment Area for 2012 Through 2017
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                                                                       Annual 99th percentile value  (ppb)                Design value  (ppb)
                                                                   -------------------------------------------------------------------------------------
                         Site Name/ID No.                                                               2017                                   2015-2017
                                                                     2012   2013   2014   2015   2016    a    2012-2014  2013-2015  2014-2016      a
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Concord/33-013-1007...............................................    7.7    8.6    9.5    7.2    4.9    N/A         9          8          7    N/A \b\
                                                                                                         \b\
Pembroke/33-013-1006..............................................   26.9   17.0   26.0   16.9   16.4   12.1        23         20         20         15
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\a\ Data from EPA's ``Air Quality Design Values'' website at https://www.epa.gov/air-trends/air-quality-design-values, accessed on July 18, 2019.
\b\ The Concord monitor ceased collection of SO2 monitoring data at the end of 2016.

B. Air Quality Modeling Data

    Regarding the second component of the attainment determination, 
i.e., air quality modeling, EPA stated in its April 23, 2014 Guidance 
that a previously submitted modeled attainment demonstration would 
suffice, along with evidence that the control strategy in the SIP has 
been fully implemented, to show attainment for a nonattainment area. In 
New Hampshire's March 16, 2018 submittal, the State provides details 
about the SO2 modeled attainment demonstration that the 
State submitted to EPA on January 31, 2017 with its SO2 
nonattainment area plan. As previously stated, EPA approved the State's 
nonattainment area plan and attainment demonstration on June 5, 2018 
(83 FR 25922). The control strategy for the nonattainment area consists 
of emission limits on Merrimack Station's SO2 emission 
units. Specifically, the emission limits for Merrimack Station are 7-
boiler operating day rolling averages that New Hampshire established as 
being comparably stringent, using a method described in EPA's April 23, 
2014 Guidance, to a 1-hour emission limit for which the attainment 
demonstration was performed. Therefore, since the emission limits have 
been fully implemented at Merrimack Station and are being complied 
with, as discussed in section V of this notice, then New Hampshire's 
attainment demonstration is a sufficient basis to show attainment for 
the Central New Hampshire nonattainment area.
    In its approved attainment demonstration, New Hampshire conducted 
air dispersion modeling using EPA's AERMOD modeling system in a manner 
consistent with the requirements and recommendations specified in 
appendix W to 40 CFR part 55, known as the Guideline on Air Quality 
Models (the Guideline). This modeling established the 1-hour ``critical 
emission value'' of 0.54 lb/million British thermal units (mmBtu) for 
emissions from Merrimack Station to attain the 1-hour SO2 
NAAQS. The State established for Merrimack Station a 7-boiler operating 
day emissions limit of 0.39 lb/MMBtu, determined to be comparably 
stringent to the critical emissions value using a method consistent 
with recommendations contained in appendix C to EPA's April 23, 2014 
Guidance. Details of New Hampshire's attainment demonstration are 
provided in EPA's proposal (82 FR 45242, September 28, 2017) and final 
action (83 FR 25922, June 5, 2018) for the approval of New Hampshire's 
nonattainment area plan and attainment demonstration.
    In summary, the monitored data show attainment in the Central New 
Hampshire nonattainment area for all three-year periods between 2012 
and 2017, inclusive. New Hampshire has demonstrated, through an 
analysis of hourly wind directions correlated with the monitored 
exceedances at the Pembroke monitor for the 2009-2011 period, that 
Merrimack Station was responsible for the violation in the area. New 
Hampshire established through its

[[Page 37190]]

attainment demonstration, air dispersion modeling that Merrimack 
Station will not cause a violation of the NAAQS in the area in the 
future. Therefore, EPA agrees that the Central New Hampshire 
nonattainment area is currently attaining the SO2 NAAQS.

IV. New Hampshire's Approved State Implementation Plan

    As described in EPA's April 23, 2014 Guidance, for EPA to 
redesignate a nonattainment area to attainment, there must be a fully 
approved SIP under section 110(k) of the CAA for the area with respect 
to the NAAQS, without any current disapproval, finding of failure to 
submit or failure to implement the SIP, or partial, conditional, or 
limited approval.
    EPA has determined that New Hampshire has a fully approved SIP with 
respect to section 110(k). On July 8, 2016, EPA approved New 
Hampshire's infrastructure SIP for the 2010 1-hour SO2 NAAQS 
(81 FR 44542), except for an aspect of the SIP related to notification 
of neighboring states, which EPA conditionally approved, and the 
interstate transport provisions, which were not included in New 
Hampshire's SIP submittal. On May 25, 2017, EPA converted the 
conditional approval to a full approval based on a proposed amendment 
to the New Hampshire SIP (82 FR 24057). On December 17, 2018, EPA 
approved the State's interstate transport provisions (83 FR 64470). As 
stated previously, New Hampshire's nonattainment area plan for the area 
was approved on June 5, 2018 (83 FR 25922). There are no elements of 
the State's SIP that are subject to disapproval, finding of failure to 
submit, or partial, conditional, or limited approval, with respect to 
the 2010 1-hour SO2 NAAQS. Therefore, the State has a fully 
approved SIP under section 110(k) of the CAA and satisfies all 
applicable requirements for the 2010 1-hour SO2 NAAQS.

V. Permanent and Enforceable Emission Reductions

    New Hampshire established stringent emissions limits and associated 
requirements for Merrimack Station on September 1, 2016 in its permit, 
TP-0189, for Merrimack Station. These emission limits were achieved 
through optimized operation of Merrimack Station's FGD system to more 
efficiently control SO2 emissions. EPA incorporated those 
permit conditions from TP-0189 into the SIP in the approval of New 
Hampshire's nonattainment area plan. SO2 emissions from 
Merrimack Station decreased by 21,388 tons (greater than 95%) in 2012, 
the first full year of FGD operation at the facility, from the previous 
year. In 2016, the facility emitted 228 tons of SO2, about 
1% of its emissions in 2011.
    According to EPA's review of more recent annual emissions 
information from the Air Markets Program Data (AMPD) tool website for 
the facility, Merrimack Station emitted 431.2 tons of SO2 in 
2018,\3\ which is about 2% of its emissions in 2011.
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    \3\ Annual emissions data from EPA's AMPD tool, available at 
https://ampd.epa.gov/ampd/.
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    In addition, EPA has reviewed emissions data from Merrimack Station 
to assess whether the State's federally-enforceable permit conditions 
are effective in controlling emissions from the facility. Specifically, 
EPA reviewed AMPD emissions data using EPA's Field Audit Checklist Tool 
(FACT) \4\ for the period between September 1, 2016, when the State's 
7-day emissions limit became effective, and March 31, 2019, which is 
the most recent date for which emissions data are currently available. 
EPA's review indicates that Merrimack Station's emissions have not 
exceeded the SIP-approved SO2 emissions limit. Furthermore, 
hourly emissions from Merrimack Station have been generally well below 
both the 1-hour critical emissions limit, which the State demonstrated 
to be comparably stringent to the permitted 7-day limit. Emissions from 
Merrimack Station were only above the critical emissions value for four 
individual hours since September 1, 2016, specifically: Twice in 2016, 
once in 2017, and once in 2018. A spreadsheet of these data and EPA's 
analysis is provided in the public docket. This operating pattern is 
consistent with EPA's expectation, as stated in EPA's approval of the 
State's nonattainment area plan, that ``the source is presumed 
occasionally to emit more than the critical emission value but on 
average, and presumably at most times, to emit well below the critical 
emission value'' (83 FR 25922, June 5, 2018). In summary, EPA's review 
of emissions information for Merrimack Station indicates that the 
facility has not exceeded its 7-day SO2 emissions limit 
contained in the TP-0189 permit, and the facility has rarely exceeded 
the 1-hour critical emissions value, as anticipated by EPA. EPA 
therefore concludes that the emissions limits incorporated into the New 
Hampshire SIP for Merrimack Station are being complied with.
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    \4\ Field Audit Checklist Tool (FACT) version 1.2.0.1, available 
for download at: www.epa.gov/airmarkets/field-audit-checklist-tool-fact. FACT provides users with metadata beyond the information 
available using the AMPD website.
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VI. Requirements for the Area Under Section 110 and Part D

    New Hampshire has submitted information demonstrating that it meets 
the requirements for the area under section 110 and part D of the CAA. 
In demonstrating that it has met all requirements for section 110 and 
part D of the CAA for the 2010 SO2 NAAQS, New Hampshire 
cited its Air Pollution Control statutes at Chapter 125-C of the New 
Hampshire Revised Statutes Annotated (RSA), and its Rules Governing the 
Control of Air Pollution in the New Hampshire Code of Administrative 
Rules at Env-A 100 through 4800, of which some (but not all) have been 
approved into the State's SIP. As stated earlier in section IV, EPA has 
approved New Hampshire's entire infrastructure SIP for SO2 
in three separate actions. This prior infrastructure SIP approval 
confirms that New Hampshire's SIP meets the requirements of CAA section 
110(a)(1) and 110(a)(2) to contain the basic program elements, such as 
an active enforcement program and permitting program.
    Section 191 of the CAA required New Hampshire to submit a part D 
nonattainment SIP for the Central New Hampshire nonattainment area by 
April 4, 2015. EPA issued a finding of failure to submit the required 
SO2 nonattainment plan by the submittal deadline for a 
number of areas, including the Central New Hampshire nonattainment area 
(81 FR 14736). New Hampshire submitted a plan for the Central New 
Hampshire nonattainment area on January 31, 2017, and EPA approved that 
plan on June 5, 2018 (83 FR 25922). Therefore, the State has met its 
obligations to establish a plan for the nonattainment area under 
section 191 of the CAA.
    Part D includes general requirements, in subpart 1, and more 
specific requirements applicable to SO2, in subpart 5, for 
nonattainment areas. For purposes of evaluating this redesignation 
request, the applicable section 172 SIP requirements for the Central 
New Hampshire area are contained in sections 172(c)(1)-(9). A thorough 
discussion of the requirements contained in section 172 can be found in 
the General Preamble for Implementation of Title I (57 FR 13498, 13564, 
April 16, 1992).
    Section 172(c)(1) requires nonattainment area SIPs to provide for 
the implementation of all reasonably available control measures (RACM) 
as expeditiously as practicable and to provide for attainment of the 
NAAQS. EPA's longstanding interpretation of the

[[Page 37191]]

nonattainment planning requirements of section 172 is that once an area 
is attaining the NAAQS, those requirements are not applicable for 
purposes of CAA section 107(d)(3)(E)(ii) and therefore need not be 
approved into the SIP before EPA can redesignate the area. In the 1992 
General Preamble for Implementation of Title I, EPA set forth its 
interpretation of applicable requirements for purposes of evaluating 
redesignation requests when an area is attaining a standard (57 FR 
13498, 13564, April 16, 1992). EPA noted that the requirements for 
reasonable further progress (RFP) and other measures designed to 
provide for attainment do not apply in evaluating redesignation 
requests because those nonattainment planning requirements ``have no 
meaning'' for an area that has already attained the standard. EPA's 
understanding of section 172 also forms the basis of its Clean Data 
Policy, which was articulated for SO2 in EPA's April 23, 
2014 Guidance and it suspends a State's obligation to submit most of 
the attainment planning requirements that would otherwise apply, 
including an attainment demonstration and planning SIPs to provide for 
RFP, RACM, and contingency measures under section 172(c)(9). Courts 
have upheld EPA's interpretation of section 172(c)(1) for ``reasonably 
available'' control measures and control technology as meaning only 
those controls that advance attainment, which precludes the need to 
require additional measures where an area is already attaining. NRDC v. 
EPA, 571 F.3d 1245, 1252 (D.C. Cir. 2009); Sierra Club v. EPA, 294 F.3d 
155, 162 (D.C. Cir. 2002); Sierra Club v. EPA, 314 F.3d 735, 744 (5th 
Cir. 2002); Sierra Club v. EPA, 375 F.3d 537 (7th Cir. 2004).\5\ 
Therefore, because the Central New Hampshire nonattainment area has 
attained the SO2 standard, no additional measures are needed 
to provide for attainment, and section 172(c)(1) requirements for an 
attainment demonstration and RACM are not part of the ``applicable 
implementation plan'' required to have been approved prior to 
redesignation per CAA section 107(d)(3)(E)(ii). In any case, in the 
context of implemented measures (especially the installation of the FGD 
at Merrimack Station, and establishment and incorporation into the SIP 
of the conditions of TP-0189), EPA believes that New Hampshire has 
satisfied the reasonably available control measures/reasonably 
available control techniques (RACM/RACT) requirement for this area.
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    \5\ Although the Court of Appeals for the Sixth Circuit has 
issued a contrary opinion in the context of redesignations for ozone 
and PM2.5, EPA believes that these opinions, interpreting 
the applicability of the ozone and PM2.5 RACM/RACT 
requirements for redesignations for those pollutants, do not address 
the applicability of the RACM/RACT requirement for SO2. 
See Sierra Club v. EPA, 793 F.3d 656 (6th Cir. 2015).
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    The other section 172 requirements that are designed to help an 
area achieve attainment are the section 172(c)(2) requirement that 
nonattainment plans contain provisions promoting reasonable further 
progress, the requirement to submit the section 172(c)(9) contingency 
measures, and the section 172(c)(6) requirement for the SIP to contain 
control measures necessary to provide for attainment of the NAAQS. 
These are also not required to be approved as part of the ``applicable 
implementation plan'' for purposes of satisfying CAA section 
107(d)(3)(E)(ii).
    Section 172(c)(3) requires submission and approval of a 
comprehensive, accurate, and current inventory of actual emissions. In 
New Hampshire's March 16, 2018 submittal, as part of its maintenance 
plan for the area, the State submitted an attainment inventory of the 
SO2 emissions from sources in the nonattainment area. New 
Hampshire chose 2011 for its base year emissions inventory, as 
comprehensive emissions data was available and updated that year. The 
State provided emissions inventories for 2014, the most recent year 
with quality assured actual emissions for the area, and the 2018 
interim year and project emissions for the 2028 maintenance year.\6\ 
EPA considers these inventories, which are summarized in Table 3, to 
satisfy the requirement of section 172(c)(3). Merrimack Station, the 
only electric generating unit (EGU) in the Central New Hampshire 
nonattainment area, remains the largest source of SO2 in the 
area, and emissions from Merrimack Station have declined substantially 
as discussed previously. For 2011 and 2014, the emissions inventories 
were based on the NEI for the respective years.
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    \6\ At least one interim year inventory is used to demonstrate 
that emissions in the area are not expected to exceed the attainment 
year inventory in the interim between the base year and the last 
year of the maintenance plan. The demonstration, by means of an 
interim year inventory, that the area will maintain the standard 
throughout the maintenance period is derived from CAA section 175A, 
which states that maintenance in the area is to be provided ``for at 
least ten years after the redesignation,'' and not just in the final 
year. Thus, a maintenance plan includes at least one interim year 
inventory to establish that, during the period that maintenance is 
projected, emissions will remain at or below the level of the 
attainment year inventory.
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    Note that New Hampshire's projected inventory for the 2028 
maintenance year, accounting for Merrimack Station's continued 
operation under the conditions established in TP-0189, show overall 
emissions in the nonattainment area about 19,046 tons lower than those 
from 2011. This large reduction is expected to be sufficient to 
maintain the SO2 standard. EPA is proposing to approve the 
2014 emissions inventory, submitted by New Hampshire along with the 
redesignation request, as meeting the section 172(c)(3) emissions 
inventory requirement.

                         Table 3--SO2 Emissions Inventories in Tons Per Year for the Central New Hampshire Nonattainment Area a
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                              On-road        Non-road
                          Year                               EGU point    Non-EGU  point   Area  sources      mobile          mobile           Total
                                                              sources         sources                         sources         sources        emissions
--------------------------------------------------------------------------------------------------------------------------------------------------------
2011....................................................          22,393             115             451              15               1          22,975
2014....................................................           1,044              63             359              14               1           1,481
2018 \b\................................................       \c\ 1,927              90             425               5               1       \c\ 2,473
2028 \b\................................................           3,443             127             353               5               1           3,929
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ New Hampshire's emissions inventory provided emissions for each of the three partial counties in the nonattainment area. This table provides only
  the area-wide emissions totals for each inventory year.
\b\ New Hampshire projected emissions for 2018 and 2028.
\c\ According to EPA's AMPD, actual emissions for Merrimack Station, the only EGU in the Central New Hampshire nonattainment area, were 431.2 tons in
  2018.

[[Page 37192]]

    Section 172(c)(4) requires the identification and quantification of 
allowable emissions for major new and modified stationary sources to be 
allowed in an area, and section 172(c)(5) requires source permits for 
the construction and operation of new and modified major stationary 
sources anywhere in the nonattainment area. EPA has determined that, 
since PSD requirements will apply to new and modified major stationary 
sources after redesignation, areas being redesignated need not comply 
with the requirement that an NSR program be approved prior to 
redesignation, provided that the area demonstrates maintenance of the 
NAAQS without part D NSR. A more detailed rationale for this view is 
described in a memorandum from Mary Nichols, Assistant Administrator 
for Air and Radiation, dated October 14, 1994, entitled ``Part D New 
Source Review Requirements for Areas Requesting Redesignation to 
Attainment.'' New Hampshire has demonstrated that the Central New 
Hampshire nonattainment area will be able to maintain the NAAQS without 
part D NSR in effect, and therefore New Hampshire does not need to have 
a fully approved part D NSR program prior to approval of the 
redesignation request. After redesignation, major new or modifying 
stationary sources would be subject to the State's Env-A 619 Prevention 
of Significant Deterioration rules and would no longer be subject to 
the State's part D NSR rules. Furthermore, EPA notes that New Hampshire 
does have a fully approved part D NSR program contained in its Env-A 
618 Nonattainment New Source Review rules. New Hampshire's Env-A 618 
and 619 rules were approved by EPA into the State's SIP on September 
25, 2015 (80 FR 57722).
    Section 172(c)(7) requires the SIP to meet the applicable 
provisions of section 110(a)(2). As noted previously, EPA has already 
approved a SIP for New Hampshire that meets the requirements of section 
110(a)(2) applicable for purposes of redesignation.
    Section 176(c) of the CAA requires States to establish criteria and 
procedures to ensure that federally supported or funded projects 
conform to the air quality planning goals in the applicable SIP. The 
requirement to determine conformity applies to transportation plans, 
programs, and projects that are developed, funded, or approved under 
title 23 of the United States Code (U.S.C.) and the Federal Transit Act 
(transportation conformity) as well as to all other federally supported 
or funded projects (general conformity). State transportation 
conformity SIP revisions must be consistent with Federal conformity 
regulations relating to consultation, enforcement, and enforceability 
that EPA promulgated pursuant to its authority under the CAA. On 
December 9, 2011, New Hampshire submitted documentation establishing 
transportation conformity procedures in its SIP. EPA approved these 
procedures on November 29, 2013 (78 FR 71504). Moreover, EPA interprets 
the conformity SIP requirements as not applying for purposes of 
evaluating a redesignation request under section 107(d) because, like 
other requirements listed above, state conformity rules are still 
required after redesignation and Federal conformity rules apply where 
state rules have not been approved. See Wall v. EPA, 265 F.3d 426 (6th 
Cir. 2001) (upholding this interpretation); see also 60 FR 62748 
(December 7, 1995) (redesignation of Tampa, Florida).
    Based on the preceding discussion, EPA is proposing to find that 
New Hampshire has satisfied all applicable requirements for purposes of 
redesignation of the Central New Hampshire nonattainment area under 
section 110 and part D of title I of the CAA.

VII. Maintenance Plan

    CAA section 175A sets forth the elements of a maintenance plan for 
areas seeking redesignation from nonattainment to attainment. Under 
section 175A, the plan must demonstrate continued attainment of the 
applicable NAAQS for at least ten years after the nonattainment area is 
redesignated to attainment. Eight years after the redesignation, the 
State must submit a revised maintenance plan demonstrating that 
attainment will continue to be maintained for the ten years following 
the initial ten-year period. To address the possibility of future NAAQS 
violations, the maintenance plan must contain contingency measures as 
EPA deems necessary to assure prompt correction of any future one-hour 
SO2 violations. Specifically, the maintenance plan should 
address five requirements: The attainment emissions inventory, 
maintenance demonstration, monitoring, verification of continued 
attainment, and a contingency plan.
    New Hampshire's March 16, 2018 redesignation request contains its 
maintenance plan, which New Hampshire has committed to review eight 
years after redesignation. New Hampshire submitted an attainment 
emission inventory which addresses current emissions and projections of 
future emissions for point, area, and mobile sources. Total 
SO2 emissions in the nonattainment area were 22,975 tons in 
the base year, 2011; 1,481 tons in the attainment year, 2014; 2,473 
tons in the projected interim year, 2018; and 3,929 tons in the 
projected maintenance year, 2028. See Table 3. EPA notes that actual 
emissions for the interim year 2018 were considerably lower than the 
State's projected emissions, indicating that the State's methods for 
projecting an inventory may overestimate emissions in the area, which 
lends additional confidence in the continued future attainment of the 
area. Furthermore, the State indicated in its redesignation request 
that the projected emissions from all sources in the Central New 
Hampshire nonattainment area in 2028 are still lower than emissions 
permitted under TP-0189 for Merrimack Station alone, which have been 
modeled to show attainment.
    New Hampshire has committed to continue to operate and maintain an 
appropriate air quality monitoring network to verify the area's 
attainment status, in accordance with the requirements of 40 CFR part 
58. These data will be used to verify continued attainment.
    New Hampshire has the authority to adopt, implement and enforce any 
subsequent emissions control measures deemed necessary to correct any 
future SO2 violations. Regarding contingency measures to 
implement in the case of a future violation of the SO2 
standard, New Hampshire has committed to use its enforcement authority 
to promptly and aggressively address permit deviations from sources in 
the Central New Hampshire area, and in particular from Merrimack 
Station.
    EPA proposes to find that New Hampshire's maintenance plan 
adequately addresses the five basic components necessary to maintain 
the SO2 standard in the New Hampshire nonattainment area.

VIII. Proposed Action

    In accordance with New Hampshire's March 16, 2018 request, EPA is 
proposing to redesignate the Central New Hampshire nonattainment area 
from nonattainment to attainment for the 2010 1-hour primary 
SO2 NAAQS. New Hampshire has demonstrated that the area is 
attaining the SO2 standard, and that the improvement in air 
quality is due to the permanent and enforceable permit conditions 
established for the main SO2 source in the nonattainment 
area. EPA is also proposing to approve the maintenance plan that New 
Hampshire submitted to ensure that the area will continue to maintain 
the SO2 standard. EPA is soliciting public

[[Page 37193]]

comments on the issues discussed in this notice or on other relevant 
matters. These comments will be considered before taking final action. 
Interested parties may participate in the Federal rulemaking procedure 
by submitting written comments to this proposed rule by following the 
instructions listed in the ADDRESSES section of this Federal Register.

IX. Statutory and Executive Order Reviews

    Under the Clean Air Act, the Administrator is required to approve a 
SIP submission that complies with the provisions of the Act and 
applicable Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). 
Thus, in reviewing SIP submissions, EPA's role is to approve state 
choices, provided that they meet the criteria of the Clean Air Act. 
Accordingly, this proposed action merely approves State law as meeting 
Federal requirements and does not impose additional requirements beyond 
those imposed by State law. For that reason, this proposed action:
     Is not a significant regulatory action subject to review 
by the Office of Management and Budget under Executive Orders 12866 (58 
FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011);
     Is not expected to be an Executive Order 13771 regulatory 
action because this action is not significant under Executive Order 
12866;
     Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Is certified as not having a significant economic impact 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
     Does not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Does not have Federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not an economically significant regulatory action based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Is not subject to requirements of Section 12(d) of the 
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 
note) because application of those requirements would be inconsistent 
with the Clean Air Act; and
     Does not provide EPA with the discretionary authority to 
address, as appropriate, disproportionate human health or environmental 
effects, using practicable and legally permissible methods, under 
Executive Order 12898 (59 FR 7629, February 16, 1994).
    In addition, the SIP is not approved to apply on any Indian 
reservation land or in any other area where EPA or an Indian tribe has 
demonstrated that a tribe has jurisdiction. In those areas of Indian 
country, the rule does not have tribal implications and will not impose 
substantial direct costs on tribal governments or preempt tribal law as 
specified by Executive Order 13175 (65 FR 67249, November 9, 2000).

List of Subjects

40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by 
reference, Intergovernmental relations, Reporting and recordkeeping 
requirements, Sulfur oxides.

40 CFR Part 81

    Environmental protection, Air pollution control, Carbon monoxide, 
Incorporation by reference, Intergovernmental relations, Lead, Nitrogen 
dioxide, Ozone, Particulate matter, Reporting and recordkeeping 
requirements, Sulfur oxides, Volatile organic compounds.

    Dated: July 25, 2019.
Deborah Szaro,
Acting Regional Administrator, EPA Region 1.
[FR Doc. 2019-16271 Filed 7-30-19; 8:45 am]
 BILLING CODE 6560-50-P