[Federal Register Volume 77, Number 150 (Friday, August 3, 2012)]
[Rules and Regulations]
[Pages 46295-46298]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-19043]



40 CFR Part 81

[EPA-HQ-OAR-2012-0233; FRL-9700-7]

Extension of Deadline for Promulgating Designations for the 2010 
Primary Sulfur Dioxide National Ambient Air Quality Standard

AGENCY: Environmental Protection Agency (EPA).

ACTION: Extension of deadline for promulgating designations.


SUMMARY: The EPA is announcing that it is using its authority under the 
Clean Air Act (CAA) to extend by up to 1 year the deadline for 
promulgating initial area designations for the primary sulfur dioxide 
(SO2) national ambient air quality standard (NAAQS) that was 
promulgated in June 2010. With this extension, the EPA is now required 
to complete initial designations for this NAAQS by June 3, 2013.

DATES: The new deadline for the EPA to promulgate designations for the 
2010 primary SO2 NAAQS is June 3, 2013.

FOR FURTHER INFORMATION CONTACT: For questions regarding this action, 
contact Rhonda Wright, Air Quality Policy Division, Office of Air 
Quality Planning and Standards, Mail Code C539-04, Environmental 
Protection Agency, Research Triangle Park, North Carolina 27711; 
telephone number: 919-541-1087; fax number: 919-541-0824; email 
address: wright.rhonda@epa.gov.

SUPPLEMENTARY INFORMATION: This preamble is organized as follows:

I. General Information
    A. Does this action apply to me?
    B. Where can I get a copy of this document and other related 
II. Background
    A. Area Designation Requirements
    B. Summary of Designations Guidance Provided in the Proposed and 
Final SO2 NAAQS Preambles and in the March 2011 and 
September 2011 Memoranda
III. Extension of Deadline for Promulgating Designations for the 
2010 NAAQS

I. General Information

A. Does this action apply to me?

    Entities potentially affected by this action include state, local, 
and tribal governments that would participate in the initial area 
designation process for the 2010 SO2 standard.

B. Where can I get a copy of this document and other related 

    The EPA has established a docket for designations for the 2010 
SO2 NAAQS under Docket ID No. EPA-HQ-OAR-2012-0233. All 
documents in the docket are listed in the www.regulations.gov index. 
Although listed in the index, some information is not publicly 
available, e.g., confidential business information or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in www.regulations.gov or in hard copy at the EPA Docket Center EPA/DC, 
EPA West, Room 3334, 1301 Constitution Avenue NW, Washington, DC The 
Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through 
Friday, excluding legal holidays. The telephone number for the Public 
Reading Room is (202) 566-1744, and the telephone number for the EPA 
Docket Center is (202) 566-1742.
    An electronic copy of this document is also available at 

II. Background

A. Area Designation Requirements

    On June 2, 2010, the EPA Administrator signed a notice of final 
rulemaking that revised the primary SO2 NAAQS (75 FR 35520, 
published on June 22, 2010) after review of the existing two primary 
SO2 standard promulgated on April 30, 1971 (36 FR 8187).\1\ 
The EPA established the revised primary SO2 NAAQS at 75 
parts per billion (ppb) which is attained when the 3-year average of 
the annual 99th percentile of 1-hour daily maximum concentrations does 
not exceed 75 ppb. The EPA determined in that rulemaking that this is 
the level necessary to provide protection of public health with an 
adequate margin of safety, especially for children, the elderly and 
those with asthma. These groups are particularly susceptible to the 
health effects associated with breathing SO2.

    \1\ Although the notice was signed on June 2, 2010, it was not 
publicly distributed until the next day, June 3, 2010. The EPA 
generally regards ``promulgation'' for public notice purposes to 
mean signature of a final rule combined with its public 
dissemination. For purposes of CAA section 107(d)(1), therefore, 
which imposes deadlines tied to the promulgation of the NAAQS for 
states to submit designations recommendations and for the EPA to 
promulgate designations, the EPA interprets the promulgation date of 
the 2010 primary SO2 NAAQS to be June 3, 2010.

    After the EPA establishes or revises a NAAQS pursuant to CAA 
section 109, the CAA directs the EPA and the states to begin taking 
steps to ensure that those NAAQS are met. The first step is to identify 
areas of the country that do or do not meet the new or revised NAAQS. 
This step is known as the initial area designations. Section 107(d)(1) 
of the CAA provides that, ``By such date as the Administrator may 
reasonably require, but not later than 1 year after promulgation of a 
new or revised NAAQS for any pollutant under section 109, the Governor 
of each state shall * * * submit to the Administrator a list of all 
areas (or portions thereof) in the state'' that designated those areas 
as nonattainment, attainment, or unclassifiable. The CAA defines an 
area as nonattainment if it is violating the NAAQS or if it is 
contributing to a violation in a nearby area. See CAA section 
    The CAA further provides, ``Upon promulgation or revision of a 
NAAQS, the Administrator shall promulgate the designations of all areas 
(or portions thereof) * * * as expeditiously as practicable, but in no 
case later than 2 years from the date of promulgation of the new or 
revised NAAQS. Such period may be extended for up to 1 year in the 
event the Administrator has insufficient information to promulgate the 
designations.'' See CAA section 107(d)(1)(B)(i).
    After the states submit their recommendations, but no later than 
120 days prior to promulgating designations, the EPA is required to 
notify a state of any intended modifications to the state's recommended 
designation. The state then has an opportunity to demonstrate why any 
proposed modification is inappropriate. Whether or not a state provides 
a recommendation, the EPA must promulgate the designation that the 
agency deems appropriate within two years of promulgation of the NAAQS 
(or within 3 years if the EPA extends the deadline).
    For the June 2010 SO2 NAAQS, the deadline for states to 
submit designation recommendations to the EPA for their areas was June 
3, 2011. The EPA has been evaluating these recommendations and 
conducting additional analyses to determine whether it is necessary to 
modify any of the state recommendations. The EPA was originally 
intending to complete the initial designations for the 2010 
SO2 NAAQS on a 2-year schedule, by June 3, 2012. We 
explained this intent in the preambles to the notices of proposed and 
final rulemakings for the revised SO2 NAAQS, and in 
subsequently issued guidance documents suggesting

[[Page 46296]]

how states could develop their designations recommendations and how 
they could develop and submit state implementation plans (SIPs) for 
attainment, maintenance and enforcement of the NAAQS. We received 
numerous comments in response to our guidance, including suggestions 
that we take the extra year allowed under the CAA to issue designations 
where insufficient information exists, and, for the reasons discussed 
below, we are persuaded that it is more reasonable to take extra time 
allowed in these circumstances, a year or less as appropriate, rather 
than to proceed with our prior intention to issue designations by June 
3, 2012.

B. Summary of Designations Guidance Provided in the Proposed and Final 
SO2 NAAQS Preambles and in the March 2011 and September 2011 

    We first explained our intentions for designations under the new 
SO2 NAAQS in the preamble to the proposed NAAQS rule, 
published in the Federal Register on December 8, 2009 (74 FR 64810). In 
the proposal, we explained that since the new SO2 ambient 
monitoring network and any newly sited monitors would not be generating 
sufficient monitoring data in time to inform the EPA decisions on 
designations, even if the EPA took an extra year, we intended to issue 
initial area designations on a 2-year schedule, by June 2012, based on 
3 years of complete, quality assured, certified air quality monitoring 
data from the pre-existing monitoring network (74 FR 64858). We then 
expected to base designations on air quality data from the years 2008-
2010 or 2009-2011, using hourly reported data from existing monitors, 
and to designate as nonattainment any area with a monitor indicating a 
violation of the 1-hour SO2 NAAQS, regardless of whether 
that monitor is located such that it could be counted towards meeting 
the proposed new network requirements (74 FR at 64859). The EPA further 
explained, however, that if the monitor indicates that the monitoring 
site meets the 1-hour SO2 NAAQS, the EPA's designation 
decision would be made on a case-by-case basis, including possibly an 
unclassifiable designation due to the EPA being unable to determine, 
due to lack of data, whether the area is violating the NAAQS or is 
contributing to a violation in a nearby area (74 FR 64859).
    In the published June 22, 2010, final NAAQS rulemaking preamble, 
partly in response to comments on the proposal, the EPA described a 
different intended approach to issuing initial area designations in 
order to make it more consistent with what we then described as our 
historical approach to implementing the prior SO2 NAAQS (75 
FR 35550). For designations, we indicated that approach would rely upon 
both monitoring data from the existing SO2 network for the 
years 2008-2010, as well as any refined SO2 dispersion 
modeling for sources that may have the potential to cause or contribute 
to a NAAQS violation, provided that it is recent and available (75 FR 
35569). Under this approach, the EPA would designate as nonattainment 
an area that has monitoring or refined modeling results showing a NAAQS 
violation, and as attainment an area that has both monitoring data and 
appropriate modeling results showing no violations (75 FR 35569). In 
general, other areas, including those with SO2 monitors 
showing no violations but without modeling showing no violations, the 
EPA would designate as unclassifiable (75 FR 35569). However, the EPA 
further explained that it anticipated making determinations of when 
monitoring alone could be appropriate to support a designation for a 
specific area on a case-by-case basis, informed by the area's factual 
record and after examining the historic treatment of the area with 
respect to prior SO2 designations as well as whether the 
area is one in which monitoring would be the more appropriate technical 
tool for determining attainment of the 1-hour NAAQS (75 FR 35552).
    The final NAAQS preamble also explained that the EPA received 
comments expressing concerns with the perceived burdens of implementing 
the proposed monitoring network as well as the sufficiency of its scope 
for purposes of identifying NAAQS violations (75 FR 35570). Some of 
these commenters suggested using modeling to determine the scope of 
monitoring requirements, or favored modeling over monitoring to 
determine attainment of the NAAQS (75 FR 35570). In response to these 
commenters, we explained our modified expectations at that time for 
issuing designations, as well as our intention to issue further 
modeling guidance (75 FR 35570). However, as we expected that it would 
take some time to issue guidance, and that modeling several hundred 
sources would represent a substantial burden, we clarified that we did 
not expect states to complete such modeling and incorporate their 
results in designations recommendations due in June 2011 (75 FR 35570). 
Rather, we expected states would generally submit designations 
recommendations of unclassifiable, and that most areas' informational 
records would be insufficient to support initial designations of either 
attainment or nonattainment (75 FR 35571).
    In March 2011, the EPA then issued a memorandum, included in the 
docket for today's extension, providing non-binding guidance on 
designations for the 2010 primary SO2 NAAQS, including 
modeling guidance (March 2011 Guidance). In this guidance, the EPA 
stated its intention at that time to promulgate initial designations 
for this standard within 2 years from the promulgation of the NAAQS 
(i.e., by June 3, 2012). (March 2011 Guidance at pp. 1-2.) Under the 
CAA, states were to submit their primary SO2 NAAQS 
designation recommendations to the EPA by June 3, 2011. The EPA stated 
in its guidance that if the EPA intends to modify any state's 
recommendation, the EPA will notify the state no later than 120 days 
prior to the EPA's action to promulgate designations (i.e., by February 
3, 2012, for designations then expected to be promulgated by June 3, 
2012). The EPA again explained that in general, due to an expected 
absence of monitoring or modeling information showing whether areas 
were meeting or not meeting the revised NAAQS, most areas would likely 
be initially designated as unclassifiable (March 2011 Guidance at p. 
    In this March 2011 Guidance, the EPA also discussed a suggested 
analytic approach that would use both air quality monitoring and 
modeling information (a ``hybrid'' modeling and monitoring approach) to 
determine if an area meets or does not meet the 2010 primary 
SO2 NAAQS initially described in the preamble for the June 
2010 primary SO2 NAAQS. Under such an approach, areas would 
generally be designated as: (1) Nonattainment, where monitoring data or 
an appropriate modeling analysis or other appropriate information 
indicate a violation; (2) attainment, where there are no monitored 
violations and an appropriate modeling analysis or other appropriate 
information demonstrate no violations; or (3) unclassifiable, where 
there are no monitored violations and no appropriate modeling analysis 
or other appropriate information sufficient to support an alternate 
designation (March 2011 Guidance at pp. 3-5). The March 2011 Guidance 
also explained that given the currently limited network of 
SO2 monitors and our expectation that states will not yet 
have completed appropriate modeling of all significant SO2 
sources, we anticipated that most areas of the country will be 
designated ``unclassifiable.''

[[Page 46297]]

    In September 2011, the EPA issued a draft guidance document on SIP 
submissions for the 2010 primary SO2 NAAQS (September 2011 
Draft Guidance). The EPA published a notice of availability of this 
draft guidance in the Federal Register on October 3, 2011 (76 FR 
61098). The EPA invited public comment on this draft document from 
October 3, 2011, to December 2, 2011 (76 FR 66925; October 28, 2011). 
This draft document includes guidance on how states could support 
future NAAQS attainment demonstrations in SIPs using a hybrid modeling 
and monitoring approach.
    The EPA received several comments questioning the appropriateness 
of using the hybrid modeling and monitoring approach to demonstrate 
attainment of the SO2 NAAQS. (See comments at Docket ID No. 
EPA-HQ-OAR-2010-1059.) Although the September 2011 Draft Guidance did 
not specifically address designations, commenters expressed their 
concerns regarding the hybrid approach both for initial designations 
purposes as well as for future SIP planning and attainment 
demonstration purposes. These concerns included, for example, industry 
sources and state regulators not having adequate time to conduct 
modeling to inform either designations recommendations that were due in 
June 2011 or SIP submissions due under the CAA in June 2013. Even in 
areas that may have monitored violations of the primary NAAQS, some 
commenters asserted uncertainty from where contributions to those 
violating ambient concentrations were coming.
    Commenters claimed that the EPA's guidance to date did not 
sufficiently enable sources and states to fully identify nearby 
contributing areas or determine the boundaries of possible 
nonattainment areas. Consequently, these commenters urged the EPA to 
take the additional time allowed under the CAA in situations where 
available data is insufficient before issuing initial designations and 
use that additional time to further refine and improve the EPA's 
expected overall approach to implementing the 1-hour SO2 
NAAQS for both current conditions influencing initial designations and 
future conditions supporting SIP attainment demonstrations.
    Subsequently, in April 2012, the EPA's Assistant Administrator for 
Air and Radiation sent letters to representatives of state and local 
government and tribal agencies that described the EPA's modified 
expectations regarding some SO2 implementation aspects, and 
that reiterated the agency's intent to proceed with initial area 
designations as expeditiously as possible given available data. (See 
sample letters at www.epa.gov/airquality/sulfurdioxide/implement.html.) 
Then, in late May and early June 2012, the EPA held numerous meetings 
with environmental advocacy, state and local government, and industry 
stakeholders regarding the EPA's overall implementation approach to the 
2010 primary SO2 NAAQS, and in these discussions 
stakeholders repeated their concerns and suggestions regarding 
designations, including the recommendations to take the extra time 
allowed under CAA section 107 where insufficient data is available. In 
addition, the EPA has publicly distributed a ``white paper'' raising 
for discussion possible alternative implementation approaches to those 
that were presented in the September 2011 Draft Guidance. (See ``White 
Paper'' at www.epa.gov/airquality/sulfurdioxide/implement.html.) The 
EPA has recently received numerous comments on the ``white paper'' and 
on the stakeholder discussions, several of which also address 
designations and which recommend taking additional time to promulgate 
them. Some of these comments also suggest that the EPA should 
significantly revise the modeling guidance contained in the March 2011 
Designations Guidance, to account for the 1-hour form of the 2010 
SO2 NAAQS, as some commenters believe that the current 
approved modeling protocol is not well suited for use in designations 
for the 1-hour NAAQS.
    The EPA is still reviewing comments and has not yet determined 
whether to revise its overall approach for issuing initial 
designations. At the same time, the EPA has also received a notice of 
intent to sue from environmental advocacy stakeholders under CAA 
section 304(a)(2) for having missed the June 3, 2012, statutory 
deadline for issuing designations that applies in the absence of a 
determination by the EPA to take the extra year allowed under CAA 
section 107 based on insufficient data.

III. Extension of Deadline for Promulgating Designations for the 2010 

    In light of the comments received on the September 2011 Guidance, 
including those regarding the timing and approach for issuing initial 
area designations, and the subsequent comments received as part of the 
stakeholder outreach process in May and June 2012, the EPA acknowledges 
that it remains significantly uncertain what analytic approach sources, 
states, and the EPA will consistently and cooperatively use to make the 
determinations required under the CAA with respect to both current and 
future air quality. Because the issues involved, and the comments 
received on the draft guidance, relate to determinations of both the 
boundaries of areas currently meeting or not meeting the NAAQS and 
whether such areas will or will not meet the NAAQS in the future, the 
EPA agrees that it should make effective use of the additional time 
allowed under the CAA to promulgate designations. The EPA has 
insufficient data at this time to promulgate designations, including 
where it is necessary to identify nearby contributing areas and to 
determine boundaries of possible nonattainment areas, which the EPA 
cannot expect to definitively determine with full cooperation of 
stakeholders in advance of resolving outstanding issues and uncertainty 
regarding the most appropriate implementation approach, including 
determining whether an area meets or does not meet the new NAAQS. 
Therefore, the EPA concludes that it currently has insufficient 
information to promulgate designations by June 2012, and intends under 
these circumstances to take additional time, up to 1 additional year, 
allowed under the CAA for promulgating initial designations for the 
2010 primary SO2 NAAQS.
    By taking the additional time, the EPA is now required under CAA 
section 107 to promulgate designations by June 3, 2013. The EPA expects 
to take additional time, as necessary, to appropriately assess 
designations. For some areas, EPA anticipates it will not be necessary 
to take the full additional year, and in those cases EPA will proceed 
sooner than June 2013. For example, the EPA intends to make its best 
effort to promulgate final designations for areas with monitored 
violations of the SO2 NAAQS by the end of calendar year 
2012, subject to being able to resolve issues related to nonattainment 
boundary determinations and contributions from nearby areas, rather 
than take until June 2013 for those areas. The EPA believes this 
deadline extension is appropriate because the continued uncertainty 
regarding the overall analytic approach to determining an area's 
compliance status affects not only the initial identification of 
nonattainment areas, but also the appropriate nonattainment area 
boundaries, which involves clearly identifying nearby areas that are 
(and are not) contributing to violations. The EPA expects to resolve 
these outstanding issues this year, and, once

[[Page 46298]]

resolved, will proceed expeditiously to complete the designations 

List of Subjects in 40 CFR Part 81

    Environmental protection, Air pollution control, National parks, 
Wilderness areas.

    Dated: July 27, 2012.
Lisa P. Jackson,
[FR Doc. 2012-19043 Filed 8-2-12; 8:45 am]