
[Federal Register Volume 81, Number 202 (Wednesday, October 19, 2016)]
[Rules and Regulations]
[Pages 71991-71997]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-25145]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R08-OAR-2016-0107; FRL-9954-13-Region 8]


Approval and Disapproval and Promulgation of Air Quality 
Implementation Plans; Interstate Transport for Utah

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The Environmental Protection Agency (EPA) is taking final 
action on portions of six submissions from the State of Utah that are 
intended to demonstrate that the State Implementation Plan (SIP) meets 
certain interstate transport requirements of the Clean Air Act (Act or 
CAA). These submissions address the 2006 and 2012 fine particulate 
matter (PM2.5) National Ambient Air Quality Standards 
(NAAQS), 2008 ozone NAAQS, 2008 lead (Pb) NAAQS, 2010 sulfur dioxide 
(SO2) NAAQS and 2010 nitrogen dioxide (NO2) 
NAAQS. The interstate transport requirements under the CAA consist of 
four elements: Significant contribution to nonattainment (prong 1) and 
interference with maintenance (prong 2) of the NAAQS in other states; 
and interference with measures required to be included in the plan for 
other states to prevent significant deterioration of air quality (prong 
3) or to protect visibility (prong 4). Specifically, the EPA is 
approving interstate transport prongs 1, 2 and 4 for the 2008 Pb NAAQS, 
approving prong 4 for the 2010 SO2 NAAQS, disapproving prong 
4 for the 2006 PM2.5, 2008 ozone, 2010 NO2 and 
2012 PM2.5 NAAQS, and disapproving prong 2 for the 2008 
ozone NAAQS.

DATES: This final rule is effective on November 18, 2016.

ADDRESSES: EPA has established a docket for this action under Docket 
Identification Number EPA-R08-OAR-2016-0107. All documents in the 
docket are listed on the http://www.regulations.gov index. Although 
listed in the index, some information may not be 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 
through http://www.regulations.gov or in hard copy at the Air Program, 
Environmental Protection Agency (EPA), Region 8, 1595 Wynkoop Street, 
Denver, Colorado 80202-1129. The EPA requests that you contact the 
individual listed in the FOR FURTHER INFORMATION CONTACT section to 
view the hard copy of the docket. You may view the hard copy of the 
docket Monday through Friday, 8:00 a.m. to 4:00 p.m., excluding federal 
holidays.

FOR FURTHER INFORMATION CONTACT: Adam Clark, Air Program, U.S. 
Environmental Protection Agency, Region 8, Mailcode 8P-AR, 1595 
Wynkoop, Denver, Colorado 80202-1129, (303) 312-7104, 
clark.adam@epa.gov.

I. Background

    On May 10, 2016, the EPA proposed action on two submittals from 
Utah for the interstate transport requirements of CAA section 
110(a)(2)(D)(i)(I) for the 2008 Pb and 2008 ozone NAAQS. 81 FR 28807. 
An explanation of the CAA requirements, a detailed analysis of the 
state's submittals, and the EPA's rationale for approval of a portion 
of the 2008 Pb submittal and disapproval of a portion of the 2008 ozone 
submittal were all provided in the notice of proposed rulemaking, and 
will not be restated here. The public comment period for this proposed 
rule ended on June 9, 2016. The EPA received four comments on the 
proposal, which will be addressed in the ``Response to Comments'' 
section, below.
    In the May 10, 2016 proposed action, the EPA proposed to disapprove 
the Utah SIP for prongs 1 and 2 of CAA section 110(a)(2)(D)(i)(I) for 
the 2008 ozone NAAQS. In that document, the EPA cited to air quality 
modeling conducted to support the promulgation of an update to the 
Cross-State Air Pollution Rule to address interstate transport with 
respect to the 2008 ozone NAAQS (CSAPR Update). The air quality 
modeling (1) identified locations in the U.S. where the EPA anticipates 
nonattainment or maintenance issues in 2017 for the 2008 ozone NAAQS 
(these are identified as nonattainment and maintenance receptors), and 
(2) quantified the projected contributions from emissions from upwind 
states to downwind ozone concentrations at the nonattainment and 
maintenance receptors in 2017. The document also

[[Page 71992]]

proposed to apply an air quality threshold of one percent of the NAAQS, 
equivalent to 0.75 ppb with respect to the 2008 ozone NAAQS, to 
determine whether a state was ``linked'' to an identified downwind air 
quality problem in another state such that the upwind state may 
significantly contribute to nonattainment or interfere with maintenance 
of the NAAQS in the downwind state. The proposal modeling data showed 
that emissions from Utah contribute above the one percent threshold to 
two identified maintenance receptors and one nonattainment receptor in 
the Denver, Colorado area. Accordingly, as the Utah Department of 
Environmental Quality (UDEQ) did not provide technical analysis to 
support the State's conclusion that emissions originating in Utah do 
not significantly contribute to nonattainment or interfere with 
maintenance of the 2008 ozone NAAQS in any other state, the EPA 
proposed to disapprove the Utah SIP as to prongs 1 and 2 of CAA section 
110(a)(2)(D)(i)(I).
    On September 7, 2016, the EPA promulgated a final CSAPR Update, 
which included updated modeling data that reflected responses to 
comments received in the context of the CSAPR Update rulemaking.\1\ The 
updated modeling projects three maintenance receptors in the Denver, 
Colorado area, but it does not project any nonattainment receptors in 
that area. Table 1 summarizes the air quality modeling results from the 
updated modeling conducted to support the final CSAPR Update relative 
to Utah. The modeling continues to indicate that Utah contributes 
emissions above the one percent threshold of 0.75 ppb with respect to 3 
maintenance receptors in the Denver, Colorado area, confirming the data 
cited at proposal.
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    \1\ A pre-publication version of the final CSAPR Update 
rulemaking can be found in the docket for this action, and is 
available at https://www3.epa.gov/airmarkets/CSAPRU/Cross-State%20Air%20Pollution%20Rule%20Update%20for%20the%202008%20Ozone%20NAAQS%202060%20AS05%20FRM.pdf (Federal Register publication 
pending).

                     Table 1--Maintenance Receptors With Utah Contribution Modeled Above 1%
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                                                                                                   Utah modeled
              Monitor I.D.                           State                      County             contribution
                                                                                                       (ppb)
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80590006................................  Colorado..................  Jefferson.................            1.03
80590011................................  Colorado..................  Jefferson.................            1.17
80350004................................  Colorado..................  Douglas...................            1.63
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    Since the updated modeling continues to indicate that the 
contributions from Utah are above the one percent threshold of 0.75 ppb 
with respect to maintenance receptors in the Denver, Colorado area, and 
because the State has not otherwise provided a technical analysis which 
demonstrates that its SIP contains adequate provisions prohibiting 
emissions that will interfere with maintenance of the 2008 ozone NAAQS 
in any other state, the EPA is finalizing a disapproval of the Utah SIP 
with respect to the prong 2 requirements of CAA section 
110(a)(2)(D)(i)(I) as to the 2008 ozone NAAQS.
    Based on this new technical information showing that there are no 
longer any projected 2017 nonattainment receptors in the Denver, 
Colorado area or any other state to which Utah contributes at or above 
the one percent threshold, the EPA is not finalizing the proposed 
disapproval with respect to prong 1 of CAA section 110(a)(2)(D)(i)(I) 
as to the 2008 ozone NAAQS, as the proposed disapproval was based on in 
part on the EPA's August 4, 2015 Notice of Data Availability (NODA) 
modeling of a projected nonattainment receptor in Denver, Colorado. 80 
FR 46271. The EPA will address the prong 1 requirements in a separate, 
subsequent rulemaking.
    On August 1, 2016, the EPA proposed action on six submittals from 
Utah for the visibility-related interstate transport requirements of 
CAA section 110(a)(2)(D)(i)(II) prong 4. 81 FR 50430. An explanation of 
the CAA requirements, a detailed analysis of the state's submittals, 
and the EPA's rationale for approval of portions of the 2008 Pb and 
2010 SO2 submittals and disapproval of portions of the 2006 
and 2012 PM2.5, 2008 ozone and 2010 NO2 
submittals were all provided in the notice of proposed rulemaking, and 
will not be restated here. The public comment period for this proposed 
rule ended on August 31, 2016. The EPA did not receive any comments on 
this proposed action.

II. Response to Comments

    Comment: Commenters UDEQ and the Wyoming Department of 
Environmental Quality (WDEQ) asserted that the CSAPR Update rulemaking 
was developed and promulgated for eastern states, and should not apply 
to western states. UDEQ stated that the EPA acknowledged in the CSAPR 
Update proposal that it will address contribution levels of western 
states like Utah on a case-by-case basis. 80 FR 75706, 75708 through 
75709, December 3, 2015. The commenters contend that the EPA should 
consider other factors beyond those considered in developing the CSAPR 
Update.
    UDEQ asserted that there are higher naturally occurring levels of 
background ozone in the west,\2\ specifically citing the EPA's draft 
Regulatory Impact Analysis for the proposed 2015 ozone NAAQS 
rulemaking, contending that ``background ozone is a relatively large 
percentage (e.g. 70-80%) of the total seasonal mean ozone in locations 
in the intermountain western United States.'' \3\ The commenter 
contends that background ozone levels in Utah and Colorado must be 
taken into consideration when evaluating nonattainment areas within the 
state borders and the impact that they have on intermountain downwind 
states.
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    \2\ See National Ambient Air Quality Standards for Ozone, 79 FR 
75234, 75382 (December 17, 2014) (proposed rule).
    \3\ EPA's draft Regulatory Impact Analysis of the Proposed 
Revisions to the National Ambient Air Quality Standards for Ozone p. 
2-16.
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    Commenter WDEQ stated that the CSAPR modeling does not adequately 
account for important regional differences between the east and the 
west, including the unique topography, altitude, weather and wildfire 
prevalence (including intensity and duration) in the western U.S. The 
commenter asserted that the EPA did not provide a technical explanation 
for how the model accounts for the differences between the eastern and 
western U.S. with regard to these factors, and that such an analysis 
should be conducted before the CSAPR modeling is applied to evaluate

[[Page 71993]]

interstate transport with respect to western states. The commenter 
recommended that the EPA work with western states to ``make regional 
adjustments and remove erroneous data from the CSAPR model.''
    Response: The commenter does not provide any evidence or technical 
basis for their claim about the inadequacies of the CSAPR Update 
modeling for the western U.S. As described in the CSAPR Update Air 
Quality Modeling Technical Support Document (AQM TSD), the CSAPR 
modeling was performed for a nationwide domain that accounted for the 
differences in emissions (including actual wild fires), meteorology, 
and topography in various regions across the U.S. The AQM TSD includes 
an evaluation of 2011 base year model performance for 8-hour daily 
maximum concentrations on a regional and statewide basis as well as for 
individual monitoring sites. For example, the performance evaluation 
results for the region that includes Utah and Colorado indicate a mean 
bias of less than 10 percent for 8-hour daily maximum predicted ozone 
concentrations compared to the corresponding measured data. As 
described more fully in the AQM TSD, the EPA's use of the CAMx source 
apportionment modeling for the CSAPR Update is appropriate and the 
Agency finds its use sufficient for the purposes of assessing and 
identifying downwind air quality problems and contributions from upwind 
states in both the eastern and the western U.S. \4\ The emissions 
modeling TSD for the CSAPR Update final rule ``Preparation of Emission 
Inventories for the version 6.3, 2011 Emissions Modeling Platform'' 
describes how fire emissions were developed and modeled using a 
consistent approach for the contiguous U.S. As described earlier, the 
most updated modeling continues to indicate that emissions from Utah 
will interfere with maintenance of the 2008 ozone NAAQS at three 
receptors in the Denver, Colorado area.
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    \4\ ``The EPA used CAMx photochemical source apportionment 
modeling to quantify the impact of emissions in specific upwind 
states on downwind nonattainment and maintenance receptors for 8-
hour ozone. CAMx employs enhanced source apportionment techniques 
that track the formation and transport of ozone from specific 
emissions sources and calculates the contribution of sources and 
precursors to ozone for individual receptor locations. The strength 
of the photochemical model source apportionment technique is that 
all modeled ozone at a given receptor location in the modeling 
domain is tracked back to specific sources of emissions and boundary 
conditions to fully characterize culpable sources.'' 80 FR 75726, 
December 3, 2015.
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    The EPA does not find the information provided by the commenters to 
indicate flaws in the modeling conducted by the EPA. Rather, the 
commenters point to factors which the CSAPR Update modeling 
specifically took into account. For these reasons, the EPA disagrees 
with these comments and finds the use of the CSAPR Update modeling to 
evaluate Utah's contributions to interstate transport is reasonable and 
supported.
    The EPA did acknowledge in the proposed CSAPR Update that ``there 
may be additional criteria to evaluate regarding collective 
contribution of transported air pollution in the West,'' and that 
``timeframe constrains the opportunity to conduct evaluations of 
additional criteria'' in the context of that rulemaking. 80 FR 75709, 
December 3, 2015. The commenters do not explain how the EPA's modeling 
has allegedly failed to consider the other factors that they contend 
should be taken into account. With respect to background 
concentrations, UDEQ has not explained how it believes the EPA must 
consider background ozone levels in evaluating interstate transport in 
the west, nor has UDEQ cited any specific provision of the statute that 
specifically requires such consideration. While the EPA does not view 
the obligation under the good neighbor provision as a requirement for 
upwind states to bear all of the burden for resolving downwind air 
quality problems, both upwind and downwind states can take reasonable 
steps to control emissions impacting downwind air quality even in areas 
affected by high levels of background concentrations of ozone. Were the 
EPA to absolve upwind states of the responsibility to make such 
reasonable reductions, the area's citizens would suffer the health and 
environmental consequences of such inaction.
    Notably, in its comment letter, UDEQ agreed that a further 
technical analysis was necessary to demonstrate that the state had 
satisfied prongs 1 and 2 of CAA section 110(a)(2)(D)(i)(I), and the 
State is in the process of developing such an analysis. The EPA will 
review that additional analysis when it is submitted to the EPA in a 
subsequent SIP submission.
    Comment: Commenter Utility Air Regulatory Group (UARG) cites to 
EPA's action to approve Arizona's SIP in spite of the CSAPR Update 
modeling indicating that the state significantly contributed to 
nonattainment at two California receptors. The commenter contends that 
the EPA's differing actions on the Utah and Arizona SIPs amount to 
developing policy about what transport criteria apply in western 
states. The commenter asserted that the EPA's actions on these two SIPs 
establish regulatory policy in a piecemeal fashion through separate, 
case-by-case rulemakings, and that this practice leads to confusion and 
uncertainty among state officials, the public, and the regulated 
community. The commenter stated that the EPA should describe the 
western transport criteria in a comprehensive rulemaking which includes 
a rationale for selecting these criteria. The commenter asserted that 
the EPA's failure to do so would deprived interested parties of an 
opportunity to provide meaningful and comprehensive comments on this 
issue.
    Response: As described in the proposal for this action and in the 
CSAPR Update, the EPA is assessing each of the western states transport 
obligations on a case-by-case basis using the information available, 
which includes information from the CSAPR Update modeling. The 
rulemaking addressing the Arizona SIP explains, as the commenter notes, 
why additional factors are relevant to evaluating Arizona's 
contribution to other states, factors that are not similarly applicable 
to Utah's contribution to the Denver receptors. Nothing in section 
110(a)(2)(D)(i)(I) requires the EPA to establish criteria for 
evaluating individual SIPs through a national rulemaking. See EPA v. 
EME Homer City Generation, L.P., 134 S.Ct. 1584, 1601 (2014) (``nothing 
in the statute places EPA under an obligation to provide specific 
metrics to States before they undertake to fulfill their good neighbor 
obligation''). As required by the CAA and Administrative Procedures 
Act, the EPA clearly described its bases for disapproving the Utah SIP 
in its proposal. Similarly, the EPA also described its bases for 
approving the Arizona SIP in its proposal for that action. The public, 
including the commenter, had an opportunity to provide meaningful and 
comprehensive comments both on the Utah and Arizona actions, and 
therefore the EPA disagrees that interested parties are deprived of an 
opportunity to comment on issues relating to the EPA's analysis of 
western transport.
    Comment: Commenter WDEQ stated that the EPA did not provide an 
explanation as to what technical analysis from the State of Utah would 
have been sufficient. Another commenter (UARG), quoting language from 
the CSAPR Update proposal (80 FR 75715, December 3, 2015), stated that 
EPA should identify and explain the additional criteria that may be 
relevant to the western states and whether it is necessary and 
appropriate to also evaluate the same criteria with respect to eastern 
states. The commenter

[[Page 71994]]

asserted that the EPA's failure to address this issue denied the public 
a meaningful opportunity to comment on it.
    Response: The Supreme Court has made clear that ``nothing in the 
statute places EPA under an obligation to provide specific metrics to 
States before they undertake to fulfill their good neighbor 
obligation.'' EPA v. EME Homer City Generation, 134 S.Ct. at 1601. 
Thus, the EPA does not agree that it is required to identify all 
relevant criteria for evaluating SIPs before taking formal action on 
the submissions. The Court explained that ``[t]he statute speaks 
without reservation: Once a NAAQS has issued, a state `shall' propose a 
SIP within three years, [40 U.S.C.] 7410(a)(1), and that SIP `shall' 
include, among other components, provisions adequate to satisfy the 
Good Neighbor Provision, [40 U.S.C.] 7410(a)(2).'' Id. It is therefore 
the responsibility of the state to demonstrate that its SIP contains 
provisions sufficient to meet the requirements of CAA section 
110(a)(2)(D)(i)(I). A state can and should submit all of the technical 
information it considers relevant to evaluate its contribution to 
downwind air quality, including anticipated changes in the emissions 
from sources within the state and any additional factors specific to 
the state that influence its emissions and air pollution which may 
transport to other states. As we noted at proposal and in this final 
action, Utah has not submitted technical information or analysis which 
leads the EPA to conclude that the state is not interfering with 
maintenance of the NAAQS in other states, particularly in light of air 
quality modeling demonstrating that emissions from Utah impact air 
quality in Denver, Colorado. The basis for this conclusion was clearly 
explained at proposal, and the EPA therefore does not agree that the 
public did not have a meaningful opportunity to comment on the factors 
relevant to the proposed disapproval of the Utah SIP submission.
    Comments regarding the factors relevant to evaluation of interstate 
transport with respect to eastern states are out of the scope of this 
rulemaking and do not require a response.
    Comment: Commenter UDEQ stated that Utah's contributions to Denver 
are modest and other factors weigh against the conclusion of 
significant contribution or interference with maintenance. UDEQ argued 
that the one percent threshold should be a screening threshold that can 
be overcome by empirical evidence. The commenter cited a proposed EPA 
action on Idaho's SIP in which EPA Region 10 did not rely solely on 
Idaho's contribution being below one percent in its action on that SIP, 
but also considered Idaho's modeling data and analysis that reinforced 
the EPA modeling results. 80 FR 66862, October 30, 2015. UDEQ argued 
that the EPA should follow this and ``consider additional factors when 
evaluating Utah's ozone infrastructure SIP.'' Commenter WDEQ claimed 
that it is appropriate for western states to use a ``weight of 
evidence'' approach, as was used in EPA Region 9's proposed action on 
Arizona's 2008 ozone transport SIP. 81 FR 15200, March 22, 2016.
    Response: The EPA encourages states to submit any relevant 
information, such as that submitted by Idaho, to assist us in 
evaluating a state's impact on downwind state's air quality and the 
control requirements in order to determine whether a state's SIP is 
approvable. The EPA agrees that it is appropriate to analyze all 
information for western states and make a conclusion based on a weight 
of the evidence, but the EPA has not received any such evidence from 
UDEQ that is sufficient to alter our determination that Utah interferes 
with maintenance at Denver area receptors.
    The EPA notes that the one percent threshold as used in the CSAPR 
rulemakings is in fact a screening threshold. States are not determined 
to significantly contribute to nonattainment or interfere with 
maintenance downwind merely because emissions from the state exceed the 
one percent threshold. Rather, the threshold is used to identify those 
states that are subject to further analysis to determine whether cost-
effective reductions are achievable from sources within the states. The 
levels of such reductions quantify the amounts of emissions that 
significantly contribute to nonattainment and interfere with 
maintenance in other states. CSAPR Update, Final Rule, pre-publication 
draft at 77-80. If UDEQ believes that the EPA should consider 
additional factors with respect to its linkage to the Denver receptors, 
it should identify those factors in its SIP submission. But as noted, 
UDEQ did not provide any technical analysis in its SIP submission, and 
to the extent additional factors have been identified in UDEQ's 
comments, it did not explain how those factors should affect the EPA's 
conclusion in this action. Without explaining how such factors should 
impact EPA's analysis, the EPA does not agree that Utah's impacts on 
the Denver receptors are modest, particularly considering emissions 
from the State contribute as much as twice the one percent air quality 
threshold, nor has the State offered any analysis to support this 
conclusory statement.
    The EPA also analyzed the State's submission and in the proposal 
described deficiencies such as a lack of quantification of the included 
emission reduction measures or evaluation of how such measures are 
sufficient to address the State's contribution to nonattainment and 
maintenance receptors in Denver, Colorado. The commenters here again 
provide no information as to why the EPA's case-specific analysis of 
Utah's SIP is incorrect.
    Comment: Commenter UDEQ asserted that the one percent screening 
threshold is arbitrary, stating that EPA only explains why it rejected 
five percent and anything below one percent, but does not justify one 
percent as opposed to two percent, which Utah meets. UDEQ argued that 
this threshold has not been subject to sufficient scrutiny and comment 
when applied to western states, and that the EPA has only determined 
that the one percent threshold is appropriate for eastern states. 80 FR 
66862-66863, October 30, 2015.
    Response: As stated in the May 10, 2016 proposal for this final 
action, the EPA believes contribution from an individual state equal to 
or above one percent of the NAAQS could be considered significant where 
the collective contribution of emissions from one or more upwind states 
is responsible for a considerable portion of the downwind air quality 
problem. The EPA's analysis has shown that the one percent threshold 
captures a high percentage of the total pollution transport affecting 
downwind states. 81 FR 28810, May 10, 2016. This threshold has been 
used by the EPA in past transport actions including the original CSAPR 
(76 FR 48208, August 8, 2011), and the EPA determined this threshold 
was appropriate following the public comment process in those previous 
rulemakings.
    In the final CSAPR Update rulemaking, the EPA compiled the 
contribution modeling results from the air quality modeling in order to 
analyze the impact of different possible thresholds, and concluded that 
the one percent threshold continues to be a reasonable means of 
accounting for the combined impact of relatively small contributions 
from many upwind states. See CSAPR Update, Final Rule, pre-publication 
draft at 81-82; AQM TSD. For each of the ozone receptors identified in 
the final CSAPR Update rule analysis, the EPA identified: (1) The total 
upwind state contributions, and (2) the amount of the total upwind

[[Page 71995]]

state contribution that is captured at one percent, five percent, and 
half (0.5) percent of the NAAQS. The EPA continues to find that the 
total collective contribution from upwind states' sources represent a 
significant portion of the ozone concentrations at downwind 
nonattainment and maintenance receptor locations. This analysis shows 
that the one percent threshold generally captures a substantial 
percentage of the total pollution transport affecting downwind states 
without also implicating states that contribute insignificant amounts. 
Analysis of the data for the Denver receptors at issue in this 
rulemaking results in the same conclusion. Use of a higher threshold 
would result in a relatively large reduction in the overall percentage 
of ozone pollution transport captured relative to the amounts captured 
at the one percent level at the receptors. For example, none of the 
transport from upwind states would be captured with a five percent 
threshold.
    Although UDEQ proposes that the EPA should instead use a two 
percent threshold with respect to the Denver receptors, it has not 
submitted additional information or analysis to assist the EPA in 
determining whether there is an appropriate alternative contribution 
threshold for Utah or western states generally. Rather, UDEQ's proposal 
to use a two percent threshold appears to only be justified by the 
conclusion that Utah would not have been linked to Denver receptors at 
this level (the updated modeling indicates contribution to a 
maintenance receptor above two percent: See Table 1 of this preamble). 
Given the lack of relevant information or analysis submitted by the 
State, and based on an analysis of EPA's own CAMx air quality modeling 
data, the EPA continues to find that the one percent threshold is 
appropriate to apply to identify upwind states linked to the Denver 
receptors.
    Comment: Commenter UDEQ asserted that the IPM model used to project 
emissions for electric generating units is not precise. The commenter 
supported this assertion by citing a comment from Louisiana Chemical 
Association (LCA) on the NODA which stated the IPM model ``is simply 
not accurate enough and is dependent upon too many uncertain 
assumptions and imprecise inputs to make binding decisions of 
`significant contribution' or `interference with maintenance' when 
dealing with projections of ozone at part per billion level.'' UDEQ 
argued that this model is imprecise and should therefore be subject to 
``opportunity for rebuttal based on empirical evidence.''
    Response: The EPA has addressed LCA's comment in the response to 
comments document on the CSAPR Update proposal. In that document, we 
noted that the D.C. Circuit Court has recognized the usefulness of 
models despite the inherent uncertainty. In upholding the EPA's 
approach to evaluating interstate transport in CSAPR, the D.C. Circuit 
held that they would not ``invalidate EPA's predictions solely because 
there might be discrepancies between those predictions and the real 
world. That possibility is inherent in the enterprise of prediction.'' 
EME Homer City Generation, L.P. v. EPA, 795 F.3d 118, 135 (2015). The 
court continued to note that ``the fact that a `model does not fit 
every application perfectly is no criticism; a model is meant to 
simplify reality in order to make it tractable.' '' Id. at 135-36 
(quoting Chemical Manufacturers Association v. EPA, 28 F.3d 1259, 1264 
(D.C. Cir. 1994).
    The EPA has also provided thorough explanation as to how the 
modeling conducted for the CSAPR Update was appropriate. As stated in 
the final CSAPR Update, ``the EPA projected future 2017 baseline EGU 
emissions using version 5.15 of the Integrated Planning Model (IPM) 
(www.epa.gov/airmarkets/power-sector-modeling). IPM, developed by ICF 
Consulting, is a state-of-the-art, peer-reviewed, multiregional, 
dynamic, deterministic linear programming model of the contiguous U.S. 
electric power sector. . . The model is designed to reflect electricity 
markets as accurately as possible. The EPA uses the best available 
information from utilities, industry experts, gas and coal market 
experts, financial institutions, and government statistics as the basis 
for the detailed power sector modeling in IPM.'' \5\ CSAPR Update, 
Final Rule, pre-publication draft at 131.
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    \5\ Detailed information and documentation of the EPA's Base 
Case, including all the underlying assumptions, data sources, and 
architecture parameters can be found on the EPA's Web site at: 
www.epa.gov/airmarkets/power-sector-modeling.
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    We have not received empirical evidence from the State to rebut our 
conclusions as stated in the proposal for this final rulemaking.
    Comment: Commenter UDEQ argued that the EPA's reliance on IPM 
modeling is incorrect in Utah's case because this modeling used a 2011 
emissions inventory that excluded certain enforceable reductions and 
included Carbon plant emissions, though the facility is no longer in 
operation.
    Response: The EPA disagrees that the IPM modeling excluded certain 
enforceable reductions and included Carbon plant emissions. The 
shutdown of the Carbon power plant was accounted for in the CSAPR 
Update modeling, and no emissions were modeled from the facility in the 
2017 scenario. (See documents and EPA-HQ-OAR-2015-0500-0205 and EPA-HQ-
OAR-2015-0500-0014 in the docket for the CSAPR Update, or in the docket 
for this rulemaking. These documents, respectively, are the NEEDS 
database which defines the starting fleet in IPM and a unit level 
comparison of emissions from point sources between the 2011 and 2017 
inventories). As for the other enforceable reductions referenced by the 
commenter, we cannot respond because the commenter has not provided 
specific detail as to the reductions that were unaccounted for. The EPA 
has encouraged and given the opportunity for states to submit 
information with regard to any inconsistencies between ``on the books'' 
upcoming reductions and the emissions modeled for the CSAPR Update in 
both that proposed rulemaking and in the August 4, 2015 NODA. 80 FR 
46271, August 4, 2015.
    Comment: Commenter UDEQ asserted that western states do not have 
confidence in the way in which they can submit data for consideration 
under the Exceptional Events Rule, which has not yet been finalized. 
UDEQ stated that ``it will be difficult for the EPA to get an accurate 
assessment of the responsibility that Utah and other western states 
have to downwind states with regard to the 2008 ozone NAAQS as used in 
CSAPR until the EPA releases a final rule on these revisions.'' 
Commenter insisted that finalization of this rulemaking will allow the 
EPA to address data influenced by wildfires, stratospheric intrusions, 
and abnormally high background ozone.
    Response: The EPA agrees that the final Exceptional Events Rule 
will assist states and the EPA in preparing and processing exceptional 
events demonstrations for events, including wildfires, which contribute 
to monitored ozone NAAQS exceedances or violations, if those events 
meet the applicable criteria in the Exceptional Events Rule, including 
(1) the event affected air quality; (2) the event was not reasonably 
controllable or preventable; and (3) the event was caused by human 
activity that is unlikely to recur at a particular location or was a 
natural event. Exceptional Events Final Rule, pre-publication draft.\6\ 
Although the rule is intended to

[[Page 71996]]

streamline the exceptional events demonstration process, there is an 
exceptional events rule and process currently in place. See 40 CFR 
50.14. We have not received and failed to act on exceptional events 
demonstrations from states that would impact the determination that 
Utah interferes with maintenance at receptors in the Denver area.
---------------------------------------------------------------------------

    \6\ See ``Treatment of Data Influenced by Exceptional Events,'' 
final rule, pre-publication draft as signed by EPA Administrator 
Gina McCarthy on September 16, 2016.
---------------------------------------------------------------------------

    The EPA disagrees with the comment's note that abnormally high 
background ozone itself may qualify as an exceptional event. An 
exceptional event must be defined by the source of its emissions. If 
the underlying source is a natural event (e.g., wildfire) and the 
emissions influence a regulatory monitor, then it can be considered for 
exclusion under the Exceptional Events Rule. If the underlying source 
is anthropogenic then the explicit text of CAA section 319 requires 
that it can only be considered under the Exceptional Events Rule if the 
activity causing emissions is unlikely to recur at a particular 
location. The meteorological processes that result in pollutant 
transport and the formation of background ozone are ongoing and thus 
not an event, even though their influence on ambient concentrations at 
a particular time and location may be observed only occasionally and 
thus seem ``event-like.'' Regardless of where the activity or event 
that caused emissions occurred, and regardless of whether the emissions 
travel internationally or interstate, all exceptional event criteria 
applicable to that activity or event must be met in order for the 
emissions to be excluded.
    Comment: Commenter WDEQ stated that the EPA's application of CSAPR 
to the western U.S. will place an undue burden on all western states. 
WDEQ noted that its department lacks staff experienced in running 
Comprehensive Air Quality Model with Extensions (CAMx version 6.11) 
modeling, and asserted that the EPA has acknowledged that this modeling 
is quite costly and resource intensive.
    Response: States are not required to conduct modeling to address 
their interstate transport requirements under CAA section 
110(a)(2)(D)(i)(I). However, where the EPA has conducted modeling that 
indicates emissions from a state may impact air quality in another 
state, both the EPA and the state must address how that modeling 
impacts any conclusion regarding the upwind state's compliance with the 
statutory interstate transport requirements. The EPA understands that 
air quality modeling can be both complex and resource intensive, and 
remains committed to assisting the states in conducting or reviewing 
air quality modeling and other relevant technical information for the 
purposes of determining compliance with CAA section 110(a)(2)(D)(i)(I).

III. Final Action

    In this action, the EPA is approving the Utah SIP with regard to 
certain interstate transport requirements of CAA section 
110(a)(2)(D)(i) for the 2008 Pb and 2010 SO2 NAAQS from the 
State's certifications as shown in Table 2 of this preamble. The EPA is 
disapproving the Utah SIP with regard to certain interstate transport 
requirements of CAA section 110(a)(2)(D)(i) for the 2006 
PM2.5, 2008 ozone, 2010 NO2 and 2012 
PM2.5 NAAQS as shown in Table 3 of this preamble. As noted 
in our August 1, 2016 proposed action, the EPA is not required to take 
further action with regard to the prong 4 disapprovals, because a FIP 
is already in place for Utah that corrects all regional haze, and thus 
visibility transport, SIP deficiencies. 81 FR 43894. This action is 
being taken under section 110 of the CAA.

 Table 2--List of Utah Interstate Transport Prongs That EPA Is Approving
------------------------------------------------------------------------
                             Final approval
-------------------------------------------------------------------------
January 19, 2012 submittal--2008 Pb NAAQS:
    (D)(i)(I) prongs 1 and 2, (D)(i)(II) prong 4.
June 2, 2013 submittal--2010 SO2 NAAQS:
    (D)(i)(II) prong 4.
------------------------------------------------------------------------



      Table 3--List of Utah Interstate Transport Prongs That EPA Is
                              Disapproving
------------------------------------------------------------------------
                            Final disapproval
-------------------------------------------------------------------------
February 21, 2010 submittal--2006 PM2.5 NAAQS:
    (D)(i)(II) prong 4.
January 31, 2013 submittal--2008 Ozone NAAQS:
    (D)(i)(I) prong 2, (D)(i)(II) prong 4.
January 31, 2013 submittal--2010 NO2 NAAQS:
    (D)(i)(II) prong 4.
December 22, 2015 submittal--2012 PM2.5 NAAQS:
    (D)(i)(II) prong 4.
------------------------------------------------------------------------

IV. Statutory and Executive Order Reviews

    Under the CAA, 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, the EPA's role is to approve state actions, 
provided that they meet the criteria of the CAA. Accordingly, this 
action merely approves some state law provisions as meeting federal 
requirements and disapproves other state law because it does not meet 
federal requirements; this action does not impose additional 
requirements beyond those imposed by state law. For that reason, this 
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);
     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 the 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 does not apply on any Indian reservation land or 
in any other area where the EPA or an Indian tribe has demonstrated 
that a tribe has

[[Page 71997]]

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).
    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. EPA will submit a report containing this action and 
other required information to the U.S. Senate, the U.S. House of 
Representatives, and the Comptroller General of the United States prior 
to publication of the rule in the Federal Register. A major rule cannot 
take effect until 60 days after it is published in the Federal 
Register. This action is not a ``major rule'' as defined by 5 U.S.C. 
804(2).
    Under section 307(b)(1) of the CAA, petitions for judicial review 
of this action must be filed in the United States Court of Appeals for 
the appropriate circuit by December 19, 2016. Filing a petition for 
reconsideration by the Administrator of this final rule does not affect 
the finality of this action for the purposes of judicial review nor 
does it extend the time within which a petition for judicial review may 
be filed, and shall not postpone the effectiveness of such rule or 
action. This action may not be challenged later in proceedings to 
enforce its requirements. (See CAA section 307(b)(2).)

List of Subjects in 40 CFR Part 52

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

    Authority:  42 U.S.C. 7401 et seq.

    Dated: September 29, 2016.
Shaun L. McGrath,
Regional Administrator, Region 8.
    40 CFR part 52 is amended to read as follows:

PART 52--APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS

0
1. The authority citation for Part 52 continues to read as follows:

    Authority:  42 U.S.C. 7401 et seq.


0
2. Section 52.2354 is amended by redesignating the introductory text as 
paragraph (a) and adding paragraph (b).
    The addition reads as follows:

Subpart TT--Utah


Sec.  52.2354   Interstate transport.

* * * * *
    (b) Addition to the Utah State Implementation Plan regarding the 
2008 Pb Standard for CAA section 110(a)(2)(D)(i) prongs 1, 2 and 4, 
submitted to EPA on January 19, 2012, and addition to the Utah SIP 
regarding the 2010 SO2 Standard for CAA section 
110(a)(2)(D)(i) prong 4, submitted to EPA on June 2, 2013.

[FR Doc. 2016-25145 Filed 10-18-16; 8:45 am]
 BILLING CODE 6560-50-P


