Approval and Promulgation of Air Quality State Implementation Plans; California; Interstate Transport Requirements for Ozone, Fine Particulate Matter, and Sulfur Dioxide, 65093-65101 [2018-27477]
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(1) EPA-APPROVED NORTH CAROLINA REGULATIONS—Continued
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BILLING CODE 6560–50–P
ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Part 52
[EPA–R09–OAR–2017–0177; FRL–9987–97–
Region 9]
Approval and Promulgation of Air
Quality State Implementation Plans;
California; Interstate Transport
Requirements for Ozone, Fine
Particulate Matter, and Sulfur Dioxide
Environmental Protection
Agency (EPA).
ACTION: Final rule.
AGENCY:
The Environmental Protection
Agency (EPA) is finalizing approval of
a State Implementation Plan (SIP)
submission from the State of California
regarding certain interstate transport
requirements of the Clean Air Act (CAA
or ‘‘Act’’). This submission addresses
the 2008 ozone national ambient air
quality standards (NAAQS), the 2006
fine particulate matter (PM2.5) and 2012
PM2.5 NAAQS, and the 2010 sulfur
dioxide (SO2) NAAQS. The interstate
transport requirements under the CAA
consist of several elements; this final
rule pertains only to significant
contribution to nonattainment and
interference with maintenance of the
NAAQS in other states.
DATES: This final rule is effective on
January 18, 2019.
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SUMMARY:
16:29 Dec 18, 2018
12/19/2018, [Insert citation of publication].
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The EPA has established a
docket for this action under Docket ID
No. EPA–R09–OAR–2017–0177. All
documents in the docket are listed on
the https://www.regulations.gov
website. Although listed in the index,
some information is not publicly
available, e.g., Confidential Business
Information (CBI) or other information
whose disclosure is restricted by statute.
Certain other material, such as
copyrighted material, is not placed on
the internet and will be publicly
available only in hard copy form.
Publicly available docket materials are
available through https://
www.regulations.gov, or please contact
the person identified in the FOR FURTHER
INFORMATION CONTACT section for
additional availability information.
FOR FURTHER INFORMATION CONTACT: Rory
Mays, Air Planning Office (AIR–2), EPA
Region IX, (415) 972–3227, mays.rory@
epa.gov.
SUPPLEMENTARY INFORMATION:
Throughout this document, ‘‘we’’, ‘‘us’’
and ‘‘our’’ refer to the EPA.
ADDRESSES:
[FR Doc. 2018–27358 Filed 12–18–18; 8:45 am]
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Table of Contents
I. Proposed Action
A. Evaluation for the 2008 Ozone NAAQS
B. Evaluation for the 2006 PM2.5 and 2012
PM2.5 NAAQS
C. Evaluation for the 2010 SO2 NAAQS
II. Public Comments and EPA Responses
III. EPA Action
IV. Statutory and Executive Order Reviews
I. Proposed Action
The California Air Resources Board
(CARB) submitted the ‘‘California
Infrastructure State Implementation
Plan (SIP) Revision, Clean Air Act
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Section 110(a)(2)(D)’’ on January 19,
2016 (‘‘California Transport Plan’’ or
‘‘Plan’’).1 This Plan addresses interstate
transport for the 2008 ozone, 2006
PM2.5, 2012 PM2.5, and 2010 SO2
NAAQS.2 On February 7, 2018, the EPA
proposed to approve the California
Transport Plan into the California SIP
because we determined that it complies
with the relevant CAA requirements.3
Our proposed action contains more
information on the California Transport
Plan and our evaluation. We summarize
the key points of our proposed
rulemaking and evaluation in this final
rule.
Sections 110(a)(2)(D)(i)(I)–(II) of the
CAA require SIPs to include provisions
prohibiting any source or other type of
emissions activity in one state from
emitting any air pollutant in amounts
that will contribute significantly to
nonattainment, or interfere with
maintenance, of the NAAQS, or
interfere with measures required to
prevent significant deterioration of air
quality or to protect visibility in any
other state. This final rule addresses the
1 Letter dated January 19, 2016, from Richard W.
Corey, Executive Officer, CARB to Jared
Blumenfeld, Regional Administrator, Region 9,
EPA.
2 The 2008 ozone NAAQS include primary and
secondary 8-hour ozone NAAQS of 0.075 parts per
million (ppm), 73 FR 16436 (March 27, 2008). The
2006 PM2.5 NAAQS include primary and secondary
24-hour NAAQS for PM2.5 of 35 micrograms per
cubic meter (mg/m3), 71 FR 61144 (October 17,
2006). The 2012 PM2.5 NAAQS include a primary
annual PM2.5 NAAQS of 12.0 mg/m3, 78 FR 3086
(January 15, 2013). The 2010 SO2 NAAQS include
a primary 1-hour SO2 NAAQS of 75 parts per
billion (ppb), 75 FR 35520 (June 22, 2010).
3 83 FR 5375.
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two requirements under section
110(a)(2)(D)(i)(I), which we refer to as
prong 1 (significant contribution to
nonattainment of the NAAQS in any
other state) and prong 2 (interference
with maintenance of the NAAQS in any
other state).4 The EPA refers to SIP
revisions addressing the requirements of
section 110(a)(2)(D)(i)(I) as ‘‘good
neighbor SIPs’’ or ‘‘interstate transport
SIPs.’’
In addition to our evaluation of the
California Transport Plan with respect
to transport of air pollution to other
states, we considered transport to the
Morongo Band of Mission Indians
(‘‘Morongo’’) and the Pechanga Band of
Luiseño Indians (‘‘Pechanga’’), given
their regulatory monitoring for certain
pollutants and comments during the
EPA’s rulemaking on California’s
interstate transport SIP for the 1997
ozone and 1997 PM2.5 NAAQS. Based
on our review of the ambient air quality
data of Morongo and Pechanga and the
emission control regimes of the South
Coast Air Quality Management District
(AQMD) for stationary sources and of
CARB for mobile sources, as described
in the EPA’s memo to the docket,5 the
EPA proposed to find that California
adequately prohibits the emission of air
pollutants in amounts that will
significantly contribute to
nonattainment, or interfere with
maintenance, of the 2008 ozone, 2006
PM2.5, 2012 PM2.5, and 2010 SO2
NAAQS in the Morongo and Pechanga
reservations. The EPA offered
consultation with each tribe at the time
of the proposal; neither tribe requested
such consultation.6
4 The remaining interstate and international
transport requirements of CAA section 110(a)(2)(D)
for the 2008 ozone, 2006 PM2.5, 2012 PM2.5, and
2010 SO2 NAAQS for California have been
addressed in prior State submissions and EPA
rulemakings. 81 FR 18766 (April 1, 2016).
Specifically, this includes the section
110(a)(2)(D)(i)(II) requirements relating to
interference with measures required to be included
in the applicable implementation plan for any other
state under part C to prevent significant
deterioration of air quality (prong 3) or to protect
visibility (prong 4), and the section 110(a)(2)(D)(ii)
requirements relating to interstate and international
pollution abatement.
5 Memorandum of January 2018 from Rory Mays,
Air Planning Office, Air Division, Region IX, EPA,
‘‘Interstate Transport for the 2008 ozone, 2006
PM2.5, 2012 PM2.5, and 2010 SO2 NAAQS and the
Morongo Band of Mission Indians and the Pechanga
Band of Luiseño Indians.’’
6 See, e.g., email dated February 27, 2018 from
Kelcey Stricker, Environmental Director, Pechanga
Band of Luiseño Mission Indians to Rory Mays, Air
Planning Office, U.S. EPA Region IX, indicating that
Pechanga did not see the need to consult. The EPA
did not receive a request for consultation or a
comparable email from the Morongo Band of
Mission Indians.
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A. Evaluation for the 2008 Ozone
NAAQS
In our proposed rulemaking the EPA
agreed with the conclusion of the
California Transport Plan that California
meets the CAA requirements for
interstate transport prongs 1 and 2 for
the 2008 ozone NAAQS. However, our
rationale differed from that presented by
CARB. The analysis in the California
Transport Plan relies primarily on
CARB’s conclusion that the ozone
transport linkages are uncertain and
therefore no significant contribution or
interference with maintenance has been
demonstrated. The EPA’s evaluation
finds that the transport linkages are
adequately quantified (and uncertainties
sufficiently addressed) and that
California’s emission control programs
adequately address the transport
requirements.
The EPA presented the various
elements of our evaluation that led to
this conclusion.7 The EPA first
explained that it approached its
evaluation considering the four-step
framework for evaluating regional ozone
transport that has been developed
through several prior regional EPA
rulemakings. This framework evaluates
downwind air quality (step 1), upwind
state linkages (step 2), and various cost
and air quality factors (step 3) to
identify whether a state will
significantly contribute to
nonattainment or interfere with
maintenance of the NAAQS in another
state and to implement any necessary
emission reductions (step 4). We
discussed the EPA’s modeling for the
Cross-State Air Pollution Rule (CSAPR)
Update rule (‘‘CSAPR Update’’),8 which
identified regulatory monitors
throughout the continental U.S. that
were expected to exceed the NAAQS in
2017 based on both projected average
design values and monitored data as
‘‘nonattainment receptors’’ (i.e., not
expected to attain) and those that may
have difficulty maintaining the NAAQS,
taking into account historic variability
in air quality, as ‘‘maintenance
receptors,’’ and estimated the
contribution of other states to the ozone
levels at each of these receptors. The
analytic year of 2017 was selected since
it corresponds to the attainment year
prior to the mid-2018 attainment
deadline for 2008 ozone NAAQS
7 For discussion of our general evaluation
approach and our specific evaluation with respect
to the 2008 ozone NAAQS, please see sections II.A
and II.B of our proposed rulemaking preamble. 83
FR 5375 (February 7, 2018).
8 81 FR 74504 (October 26, 2016).
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nonattainment areas classified as
Moderate.
We addressed CARB’s assertions
regarding ozone transport modeling
uncertainties (relating to a prior, similar
iteration of the EPA’s ozone transport
modeling) for identifying nonattainment
and maintenance receptors in 2017 and
linkages from California to downwind
receptors, and discussed the contrast
that CARB draws between ozone
transport in the eastern versus western
U.S.
Based on our analysis, we proposed to
find that California is linked to three
maintenance receptors in the Denver,
Colorado area. This conclusion was
based on a combination of factors: (1)
The EPA’s projection that California
emissions would contribute above 1
percent of the 2008 ozone NAAQS at
each of the three receptors (1.1 to 2.6
percent), (2) other states also contribute
above 1 percent of the NAAQS to these
receptors, and (3) the average interstate
contribution to ozone concentrations
from all states upwind of these receptors
was both considerable (9.2 to 9.4
percent of the projected ozone design
values) and comparable to collective
contributions from upwind states to
receptors in Texas as evaluated in the
CSAPR Update. Accordingly, we
proposed that a 1 percent threshold is
appropriate as an air quality threshold
to determine whether California is
‘‘linked’’ to the three maintenance
receptors in the Denver area for the 2008
ozone NAAQS.
Our proposed finding that California
is linked to the three Denver area
receptors prompted further inquiry into
whether the contributions would
interfere with maintenance at the
receptors and whether there are costeffective controls that can be employed
to reduce emissions. To do so, we
presented a general assessment of the
emission sources in California,
including mobile and stationary
emission sources. We proposed to find
that control measures in the California
SIP for mobile sources, large electricity
generating units (EGUs), and large nonEGU sources (e.g., cement plants and oil
refineries), adequately prohibit the
emission of air pollution in amounts
that will interfere with maintenance of
the 2008 ozone NAAQS at the identified
receptors in the Denver area.
We discussed California’s mobile
source measures, which are primarily
adopted and implemented by CARB,
and stationary source measures, which
are primarily adopted and implemented
by California’s 35 local air districts. For
the latter, beyond the measures
described in the California Transport
Plan, we also considered stationary
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source control measures for EGUs,
consistent with the controls analysis for
the CSAPR and CSAPR Update
rulemakings,9 and examples of
stationary source control measures for
the largest non-EGU sources in the
State.
We noted that California mobile
sources account for approximately 70
percent of the projected 2017 nitrogen
oxide (NOX) emissions and that CARB
has established a comprehensive
program to control and reduce mobile
source emissions within the state. The
EPA has approved many of CARB’s
mobile source regulations as part of the
California SIP, including regulations
establishing standards and other
requirements relating to emissions from
cars, light- and medium-duty trucks,
heavy-duty trucks, commercial harbor
craft, mobile cargo handling equipment,
marine engines and boats, and offhighway recreational vehicles. To
support and enhance these emissions
standards, we also noted that CARB has
established specific gasoline and diesel
fuel requirements, and the California
Bureau of Automotive Repair has
established a vehicle emissions and
inspection (i.e., ‘‘smog check’’) program.
With respect to stationary and area
emission sources, we noted that the
California SIP has hundreds of rules that
limit the emissions of NOX and volatile
organic compounds (VOCs) and that
many of these rules were developed by
local air districts to reduce ozone
concentrations in response to the prior
1979 1-hour ozone and 1997 8-hour
ozone NAAQS.
For EGUs producing greater than 25
megawatts of electricity, including nonfossil fuel EGUs, we described how
California’s statewide NOX emissions
rate is very low (0.0097 pounds of NOX
per million British thermal units in
2018) and ranks as the 47th lowest out
of the 48 contiguous states and
Washington, DC for which the EPA
performed power sector modeling in the
context of the CSAPR Update. We found
that California produces electricity very
efficiently in terms of NOX emissions
and is therefore unlikely to have
significant, further NOX reductions
available from the EGU sector at
reasonable cost.
In investigating the potential for
further NOX emissions reductions from
EGUs, we found that additional NOX
reductions from EGUs in California
would cost more than three times the
amount that the EPA determined to be
cost-effective to partially address ozone
transport obligations in the eastern U.S.
9 76 FR 48208 (August 8, 2011) and 81 FR 74504
(October 26, 2016), respectively.
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under the CSAPR Update (i.e.,
reductions expected above $5,000 per
ton of NOX in California versus a costeffective control level of $1,400 per ton
in the CSAPR Update rulemaking for 22
eastern states). Further, we noted that
the largest collection of EGU facilities
emitting over 100 tons per year (tpy) of
NOX, per the 2011 National Emissions
Inventory, are found in the San Joaquin
Valley, Bay Area, and South Coast air
districts and are subject to district rules
that limit NOX emissions and have been
approved into the California SIP.
For non-EGU stationary sources, we
found that they emitted 6.7 times more
NOX than EGUs in California in 2011.
Of these sources, 19 emitted over 500
tpy of NOX, including Portland cement
plants, petroleum refineries, and several
other source types, and accounted for
two thirds of the NOX emissions from
California stationary sources that
emitted over 100 tpy in 2011 and 5.2
percent of the total 2011 NOX inventory
for California. These 19 sources are in
the Bay Area, Kern County, Mojave
Desert, San Joaquin Valley, and South
Coast air districts and, overall, are
subject to rules that limit NOX
emissions and have been approved into
the California SIP. For the small number
of large non-EGU sources that are either
subject to NOX control measures that
have not been submitted for approval
into the California SIP, or fall outside
the geographic jurisdiction of the
applicable district rules, we found that
further emission controls would be
unlikely to reduce any potential impact
on downwind states’ air quality because
such sources comprise no more than 0.8
percent of the total NOX emitted in
California in 2011.
In sum, on the strength of CARB and
the local air districts’ emission control
programs, especially for mobile and
stationary sources of NOX, we proposed
that the California SIP adequately
prohibits the emission of air pollutants
in amounts that will significantly
contribute to nonattainment, or interfere
with maintenance, of the 2008 ozone
NAAQS in any other state. The EPA also
noted that recent modeling shows that
by the 2023 ozone season the receptors
identified in Denver are projected to be
‘‘clean,’’ i.e., both the average and
maximum design values are projected to
be below the level of the 2008 ozone
NAAQS.10
10 Memorandum
dated October 27, 2017 from
Stephen D. Page, Director, EPA Office of Air Quality
Planning and Standards, to Regional Air Division
Directors, Regions 1–10. Available at: https://
www.epa.gov/sites/production/files/2017-10/
documents/final_2008_o3_naaqs_transport_memo_
10-27-17b.pdf.
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B. Evaluation for the 2006 PM2.5 and
2012 PM2.5 NAAQS
The EPA proposed to approve the
California Transport Plan for the CAA
requirements for interstate transport
prongs 1 and 2 for the 2006 PM2.5 and
2012 PM2.5 NAAQS. First, we discussed
our evaluation of CARB’s identification
of nonattainment and maintenance
receptors in western states based on
data presented in the California
Transport Plan as well as the EPA’s
analysis of 2009–2013 24-hour and
annual PM2.5 design values. Based on
that evaluation, we presented modified
lists of such receptors that largely follow
the lists of receptors in the California
Transport Plan.
For the 2006 24-hour PM2.5 NAAQS,
we derived a list of 18 potential
nonattainment receptors and three
potential maintenance receptors within
11 western states (excluding
California) 11 that accounted for the
information presented in the California
Transport Plan and ambient air quality
and emissions data that were common
to our evaluation of both the 24-hour
and annual NAAQS. We also presented
the 24-hour PM2.5 design values for
2014–2016 at each identified receptor.
For the 2012 annual PM2.5 NAAQS,
we did not find that there would be any
potential nonattainment receptors and
we identified two potential maintenance
receptors, one in Idaho and one in
Pennsylvania. To do so, we relied on
photochemical modeling results
presented in the EPA’s informational
memo on interstate transport for the
2012 PM2.5 NAAQS (‘‘2012 PM2.5
NAAQS Transport Memo’’), which
projected annual PM2.5 design values for
2017 and 2025 at each regulatory PM2.5
monitor in the continental U.S.12 We
used those results to evaluate projected
air quality in 2021, which corresponds
to the attainment deadline for 2012
PM2.5 NAAQS nonattainment areas
classified as Moderate. We also
addressed some differences in the
receptors identified by CARB and those
identified by the EPA and considered
the annual PM2.5 design values for
2014–2016 at the potential maintenance
receptors identified in the EPA’s 2012
PM2.5 NAAQS Transport Memo.
We then discussed California
emissions of PM2.5 and its precursors,
California’s regulations to limit such
emissions, and the emissions trends
11 For purposes of this rulemaking, ‘‘western
states’’ refers to the states of Arizona, California,
Colorado, Idaho, Montana, Nevada, New Mexico,
Oregon, Utah, Washington, and Wyoming.
12 2012 PM
2.5 NAAQS Transport Memo, Table 1,
5. Available at https://www.epa.gov/pm-pollution/
information-interstate-transport-good-neighborprovision-2012-fine-particulate-matter.
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resulting from such regulations. We
discussed California’s control measures
before our more specific discussion of
interstate transport prongs 1 and 2 for
each NAAQS because such discussion
provided a common basis for evaluating
the California emissions component of
CARB’s weight of evidence analysis. For
three PM2.5 precursors pollutants, we
incorporated our evaluation of
California’s emissions and regulatory
programs for NOX and VOC (for the
2008 ozone NAAQS) and oxides of
sulfur (SOX) (for the 2010 SO2
NAAQS).13 For directly-emitted PM2.5,
we affirmed that many of California’s
measures limit the emission of
particulate matter and have been
approved into the California SIP. These
include the State’s mobile source
emission standards and test procedures
for heavy-duty engines and vehicles,
passenger cars, light duty trucks, and
medium duty vehicles; in-use diesel
standards for heavy-duty trucks, buses,
drayage trucks, and off-road vehicles;
and inspection and maintenance
programs, as well as air district
stationary source measures for
combustion sources of PM2.5, such as
open burning, refineries, and cement
plants, and dust sources of PM2.5, such
as fugitive dust from roads and
agricultural operations.
We also described trends in California
emissions, which have decreased by
substantial amounts (e.g., statewide
decreases from 2000 to 2016 of 75
percent direct PM2.5, 66 percent NOX, 54
percent VOC, and 75 percent SO2) in
response to state and local control
measures, as well as federal measures
for sources outside California’s
regulatory authority.
Based on our review of the state and
local measures cited in the California
Transport Plan that limit the emission of
PM2.5 and its precursor pollutants and of
the applicable California emission
trends, which are generally decreasing,
we agreed with CARB’s general
conclusions regarding interstate
transport of PM2.5: That California
emissions from stationary sources are
subject to stringent limits for direct
PM2.5 and its precursors (e.g., NOX and
SOX); that California has a long history
of reducing emissions through motor
vehicle and fuel standards; and that
state and local measures will continue
to reduce the potential for California
emissions to contribute significantly to
nonattainment, or interfere with
maintenance, of the 2006 24-hour PM2.5
13 CARB estimates that SO comprises 97% of the
2
state-wide SOX inventory and therefore used
California SOX emissions in its analysis to represent
California SO2 emissions. California Transport Plan,
App. C, C–1.
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or 2012 annual PM2.5 NAAQS in any
other state.
Building on the identification of
potential nonattainment and
maintenance receptors and our
discussion of California emissions, we
presented the EPA’s weight of evidence
analysis to address the CAA
requirements, which affirmed CARB’s
weight of evidence analysis for the 2006
24-hour PM2.5 and 2012 annual PM2.5
NAAQS. We prepared a Technical
Support Document (TSD) containing our
more detailed analysis of interstate
transport for the 2006 24-hour PM2.5
NAAQS (‘‘EPA’s PM2.5 Transport TSD’’),
which was also relevant for our
evaluation of the 2012 annual PM2.5
NAAQS.14
For interstate transport prongs 1 and
2 for the 2006 24-hour PM2.5 NAAQS,
we summarized our evaluation of the
areas encompassing the 18
nonattainment receptors, grouping them
into three geographic bins (i.e., Arizona,
the Northern Rocky Mountains, and
Utah) based on the nature of the
emission sources affecting the receptors,
and the areas encompassing the three
maintenance receptors, grouping them
by the two relevant states (Montana and
Utah).
For each receptor area we described
our review of the information compiled
and presented in the California
Transport Plan, including distance of
relevant receptors from California;
intervening terrain; potential wildfire
effects; chemical speciation data; local
topography; the effect of local emission
sources, particularly residential wood
burning and, in certain cases, other
sources (e.g., mobile sources,
agricultural activities), on wintertime
exceedances; and regional background
levels represented by ambient 24-hour
PM2.5 data from Interagency Monitoring
of Protected Visual Environments
(IMPROVE) monitoring sites. We
reviewed California’s emissions and
emission control programs for PM2.5 and
its precursors, especially for NOX and
SOX, and concluded that California has
an extensive and effective program for
limiting emissions of such pollutants.
Thus, we proposed that California will
not significantly contribute to
nonattainment or interfere with
maintenance of the 2006 24-hour PM2.5
NAAQS in any western state.
As the California Transport Plan did
not evaluate PM2.5 transport to states
farther east than Montana, Wyoming,
Colorado, and New Mexico, we
evaluated the potential for transport of
14 ‘‘EPA Evaluation of the California Interstate
Transport Plan (2006 PM2.5 NAAQS), Technical
Support Document,’’ EPA, Region IX, January 2018.
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PM2.5 and its precursors to states farther
east. We did so by reviewing modeling
data from the CSAPR and recent air
quality data to identify the westernmost
area in the East 15 with potential
nonattainment or maintenance
receptors, and then comparing
California’s likely contributions with
the contributions of intervening states
that may significantly contribute to
nonattainment or interfere with
maintenance of the NAAQS at the
potential nonattainment and
maintenance receptors, respectively.
We concluded that California
emission sources will not significantly
contribute to nonattainment or interfere
with maintenance of the 2006 PM2.5
NAAQS at the westernmost
nonattainment and maintenance
receptors in the East, which were in
Madison County, Illinois. This was
based on the generally improved air
quality in the East since the EPA’s
analysis in 2011 for CSAPR, which
reduced the number of potential
nonattainment or maintenance
receptors; the distance of the Madison
County, Illinois receptors from
California; intervening terrain; our
analysis of the westernmost states
linked to the Madison receptors and
comparison of California emissions; the
large reductions in emissions of PM2.5
and its precursors in California; and the
trend of decreasing 24-hour PM2.5
concentrations at the Madison receptors.
As the distance from California to the
other potential eastern nonattainment or
maintenance receptors is even greater,
we noted that the expected contribution
from California to 24-hour PM2.5
concentrations at such receptors would
be even smaller and thus not
significantly contribute to
nonattainment or interfere with
maintenance of the 2006 24-hour PM2.5
NAAQS in any state farther east than
Montana, Wyoming, Colorado, and New
Mexico.
For interstate transport prongs 1 and
2 for the 2012 annual PM2.5 NAAQS, we
agreed with CARB that California will
not significantly contribute to
nonattainment, or interfere with
maintenance, of the 2012 annual PM2.5
NAAQS in any other state and
presented our analysis for potential
maintenance receptors in Lemhi and
Shoshone counties, Idaho and
Allegheny County, Pennsylvania.
15 For purposes of the PM
2.5 evaluation in this
notice, ‘‘the East’’ refers to the 37 states and
Washington, DC that lie east of the states of
Montana, Wyoming, Colorado, and New Mexico.
The EPA modeled the contribution of states within
the East to each receptor for CSAPR but did not
model the contribution of any state further west,
such as California.
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For the potential maintenance
receptors in Idaho, we reviewed the
information compiled and presented in
the California Transport Plan, including
distance of these monitors from
California; intervening terrain; wildfire
effects; local topography; the effect of
local emission sources on wintertime
exceedances of the 24-hour NAAQS and
the effect of those exceedances on
annual PM2.5 concentrations; and rural
background levels represented by
IMPROVE data. We reviewed
California’s emissions and emission
control programs for PM2.5 and its
precursors, especially for NOX and SOX,
and concluded that California has an
extensive and effective program for
limiting emissions of such pollutants.
Thus, we proposed that California will
not significantly contribute to
nonattainment or interfere with
maintenance of the 2012 annual PM2.5
NAAQS in Idaho or any western state.
For the potential maintenance
receptor in Allegheny County,
Pennsylvania, we concluded that
California emission sources will not
interfere with maintenance of the 2012
annual PM2.5 NAAQS. This was based
on our interpolated projection that the
Allegheny monitor will likely be
attaining the annual PM2.5 NAAQS in
2021; the distance of this receptor from
California; intervening terrain; the
contribution modeling performed for
CSAPR; the large reductions in
emissions of PM2.5 and its precursors in
California; and the general trend of
decreasing annual PM2.5 concentrations
at the Allegheny receptor.
Based on our analysis that there are
no nonattainment receptors outside of
California for the 2012 PM2.5 NAAQS,
and our analysis for the maintenance
receptors in Idaho and Pennsylvania, we
proposed that California will not
significantly contribute to
nonattainment, or interfere with
maintenance, of the 2012 PM2.5 NAAQS
in any other state.
C. Evaluation for the 2010 SO2 NAAQS
The EPA proposed to approve the
California Transport Plan for the CAA
requirements for interstate transport
prongs 1 and 2 for the 2010 SO2
NAAQS. We described how our
evaluation of SO2 transport required a
slightly different approach than our
evaluation for regional pollutants, such
as ozone and PM2.5, and more localized
pollutants, like lead, given the universe
of SO2 emission sources and physical
properties of SO2 in the atmosphere
relative to those other pollutants. In our
evaluation we addressed the air quality,
emission sources, and emission trends
in the states bordering California, i.e.,
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Arizona, Nevada, and Oregon. Then we
discussed California’s air quality,
emissions sources, control measures,
and emission trends with respect to
interstate transport prong 1, followed by
discussion of additional California air
quality trends and emission trends with
respect to interstate transport prong 2.
We found that monitored 1-hour SO2
levels in Arizona, Nevada, and Oregon
are generally well below 75 ppb; that
sources in these bordering states that
emit over 2,000 tpy of SO2 are located
at a distance well beyond a 50-km buffer
from California’s borders where
emissions from California sources might
be expected to have downwind impacts
on air quality; and that the downward
SO2 emission trends in each bordering
state reduce the likelihood of SO2
nonattainment or maintenance issues
appearing in the future.16
For interstate transport prong 1, the
EPA reviewed the analysis presented in
the California Transport Plan and
considered additional information on
ambient SO2 monitoring data, SO2
emission sources and controls,
including state measures for mobile
sources and air district measures for
large stationary sources, and emission
trends in California. As for Arizona,
Nevada, and Oregon, monitored 1-hour
SO2 levels in California are low (most
often below half the level of the 2010
SO2 NAAQS); the 29 SO2 sources in
California that emit over 100 tpy of SO2
are located at a distance well beyond 50
km from California’s borders, the
distance where emissions from
California sources might be expected to
have downwind impacts on air quality
in bordering states; and California’s
decreasing SO2 emission trend each
reduce the likelihood of California
emitting SO2 in amounts that would
adversely affect other states in the
future.
Therefore, based on our analysis of
SO2 air quality and emission sources in
Arizona, Nevada, and Oregon and our
analysis of SO2 air quality and
emissions in California, we proposed
16 This final approval of the California Transport
Plan for the 2010 SO2 NAAQS under CAA section
110(a)(2)(D)(i)(I) is based on the information
contained in the administrative record for this
action and does not prejudge any other future EPA
action that may make other determinations
regarding California’s air quality status. Any such
future actions, such as area designations under any
NAAQS, will be based on their own administrative
records and the EPA’s analyses of information that
becomes available at those times. Future available
information may include, and is not limited to,
monitoring data and modeling analyses conducted
pursuant to the EPA’s SO2 Data Requirements Rule
(80 FR 51052, August 21, 2015) and information
submitted to the EPA by states, air agencies, and
third-party stakeholders such as citizen groups and
industry representatives.
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65097
that California will not significantly
contribute to nonattainment of the 2010
SO2 NAAQS in any other state, per the
requirements of CAA section
110(a)(2)(D)(i)(I).
For interstate transport prong 2, the
EPA reviewed the analysis presented in
the California Transport Plan and
considered additional information on
California air quality trends and
emission trends to evaluate CARB’s
conclusion that California does not
interfere with maintenance of the 2010
SO2 NAAQS in other states. The EPA’s
analysis built on our evaluation of air
quality and SO2 emission sources in
Arizona, Nevada, and Oregon, and our
evaluation for significant contribution to
nonattainment (prong 1) based on the
evidence that we reviewed (i.e., low
ambient concentrations of SO2, large
distance of SO2 sources from the
California border, decreasing SO2
emissions, and the existence of SIPapproved California control measures).
We found that from 2000 to 2015 both
ambient SO2 concentrations and SO2
emissions from California’s largest
stationary sources have decreased
substantially; and that state and local
measures to limit the sulfur content of
fuels and limit SO2 emissions will
continue to limit SO2 emissions that
might adversely affect other states.
Accordingly, we proposed that
California SO2 emission sources will not
interfere with maintenance of the 2010
SO2 NAAQS in any other state, per the
requirements of CAA section
110(a)(2)(D)(i)(I).
II. Public Comments and EPA
Responses
The 30-day comment period for the
EPA’s proposed rulemaking closed on
March 9, 2018. We received four
comment letters in response to the
proposed rulemaking. CARB submitted
a letter affirming its support for the
EPA’s proposed approval.17 The Center
for Biological Diversity (CBD) submitted
adverse comments regarding the State’s
and the EPA’s evaluation of interstate
transport for the 2008 ozone NAAQS.18
The two remaining letters were
anonymous comment letters that raised
issues outside the scope of this
rulemaking and did not identify any
material issues necessitating a
17 Letter dated March 9, 2018, from Kurt
Karperos, Deputy Executive Officer, CARB to Alexis
Strauss, Acting Regional Administrator, EPA Region
IX.
18 Letter dated March 9, 2018, from Robert
Ukeiley, Senior Attorney, Center for Biological
Diversity to Rory Mays, Air Planning Office, EPA
Region IX.
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response.19 The comment letters are
available in the docket for this
rulemaking.
CBD requests that the EPA disapprove
the California Transport Plan with
respect to the 2008 ozone NAAQS. We
address CBD’s comments in three parts
as follows.
Comment #1: The commenter states
that the ozone transport analysis in the
California Transport Plan is flawed
because it underestimates NOX
emissions from agricultural soils in
California. The commenter relies on a
recent study that concludes that
agricultural soils are a dominant source
of California’s NOX emissions (‘‘Soil
NOX Study’’), especially in the San
Joaquin Valley.20 Based on this study,
the commenter states that California’s
NOX emissions would have been 20 to
51 percent higher and that, by
underestimating such emissions, the
California Transport Plan
underestimated California’s
contribution to downwind states. The
commenter recommends re-running
ozone transport modeling with a
corrected NOX emission inventory for
California and suggests that this could
change the linkages between California
and other states for ozone. The
commenter asserts that, pursuant to the
Supreme Court’s holding in Motor
Vehicle Manufacturers Association v.
State Farm Mutual Automobile
Insurance, it is unlawful to fail to
consider an important aspect of a
problem before the agency.21
Response #1: The EPA disagrees that
the California Transport Plan is flawed
in this manner and that the EPA failed
to consider an important aspect of
interstate transport for the 2008 ozone
NAAQS. As an initial matter, the
CSAPR Update modeling estimates that
California contributes more than 1
percent of the NAAQS to downwind
maintenance receptors in Denver (i.e.,
California is ‘‘linked’’ to receptors in
Denver). An increase in NOX emissions
from California could potentially
increase the magnitude of the
contribution to these receptors but
would be unlikely to result in any
additional downwind linkages for
California because there are no other
19 Comments received on February 21, 2018 and
February 27, 2018.
20 Almaraz, et al., ‘‘Agriculture is a major source
of NOX pollution in California,’’ Science Advances,
January 31, 2018, 1. As this article is copyrighted,
it is available in hard copy, but not available
electronically at Regulations.gov, as part of the
docket of this rulemaking; see the ADDRESSES
section of this action for hard copy viewing
information. It is also publicly available at: https://
advances.sciencemag.org/content/4/1/eaao3477/
tab-pdf.
21 463 U.S. 29, 43 (1983).
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nonattainment or maintenance receptors
in the West (excluding California),
based on EPA’s CSAPR Update
modeling. Moreover, in the CSAPR
Update four-step process, the amount of
contribution above the 1 percent
threshold is not a factor in determining
whether the upwind state’s contribution
is significant or will interfere with
maintenance.22
Although the study upon which the
commenter relies was not published
until after the EPA’s proposed
rulemaking was signed on January 26,
2018, we have considered the
commenter’s statement and the study on
possible underestimation of NOX
emissions from agricultural soils in
California and potential effects in
analyzing California’s contribution to
ozone in downwind states. Accordingly,
we present a brief synopsis of how the
CSAPR Update modeling accounted for
NOX emissions from land in California,
as well as a summary of the Soil NOX
Study referenced by the commenter and
our evaluation thereof with respect to
this rulemaking.
In 2016, the EPA’s CSAPR Update
modeling used NOX emissions from
soils for the continental U.S based on
application of the Biogenic Emissions
Inventory System (BEIS version 3.61).23
Emissions of soil NOX vary by land
cover type and, accordingly, model
emission factors vary for each type of
land cover. For example, the emission
factor for agricultural lands is relatively
higher than grasslands due to
application of nitrogen-based fertilizers.
The annual soil NOX emissions from
22 The 1 percent threshold can serve to limit the
scope of an upwind state’s emission reduction
obligation if upwind emission reductions would
otherwise reduce a state’s impact to below the
threshold. See EME Homer City Generation, L.P. v.
EPA, 134 S. Ct. 1584, 1608–09 (2014) (the EPA
cannot require a state to reduce its contribution to
every receptor to which it is linked to below 1
percent of the NAAQS). In this action, however, the
EPA has not concluded that California’s impact to
any downwind receptors would be reduced below
the 1 percent threshold as a result of the emission
controls implemented by the State’s SIP. Therefore,
the potential additional impact of NOX emissions
resulting from agricultural soils would not
implicate this limit on the Agency’s statutory
authority.
23 Information on BEIS can be found at https://
www.epa.gov/air-emissions-modeling/biogenicemission-inventory-system-beis. This web page
includes a brief version history of BEIS, including
points at which the system’s soil NO algorithm was
revised based on the work of peer-reviewed
research papers, and a list of BEIS references at
https://www.epa.gov/sites/production/files/201510/documents/beis_references.pdf. The EPA’s
emissions modeling platform TSD for the CSAPR
Update final rule describes how BEIS was used to
estimate emissions from soils and vegetation.
‘‘Technical Support Document (TSD) Preparation of
Emission Inventories for the Version 6.3, 2011
Emissions Modeling Platform,’’ EPA, August 2016,
33–35.
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California were estimated to be 30,593
tpy in both 2011 and 2017, which
corresponds to 4.1 percent of the total
2011 NOX inventory for California
(740,179 tpy) and 5.6 percent of the total
2017 base case NOX inventory (544,972
tpy), respectively. Thus, the CSAPR
Update modeling accounted for the
effect of California’s soil NOX emissions
on ozone formation and downwind
transport to other states.
In the Soil NOX Study, the authors
generated annual estimates of soil NOX
emissions from California using a
nitrogen isotope model and the
Integrated Model for the Assessment of
the Global Environment at a 4 kilometer
(km) by 4 km resolution. These complex
biogeochemical models include the full
suite of variables thought to contribute
to soil NOX emissions. The model
results were compared to a limited
number of observations from surface
measurements around California. The
average modeled NOX emissions were
comparable to the surface measurements
in some areas and larger than the
surface measurements in other areas.24
The authors then compared model
predicted emissions to CARB’s non-soil
NOX emissions inventory and estimated
that soil NOX emissions account for 25
percent of California’s total NOX
emissions.25 They note that this is in the
range of previous modeling studies that
considered agricultural soils worldwide.
With respect to the San Joaquin Valley,
the study also used airborne and surface
measurements of NOX from a separate
study 26 to estimate total NOX emissions
from a portion of the San Joaquin Valley
of 190 metric tons of nitrogen per day
(tnpd), with a range of plus or minus
130 tnpd.
The Soil NOX Study concludes that it
is the first study to include a spatially
explicit estimate of soil NOX emissions
compared to other emission sources in
California. While acknowledging the
uncertainty in the estimate, the Soil
NOX Study further concludes that its
model results add to a growing body of
24 Soil
NOX Study, Table 1, 3.
Soil NOX Study notes that CARB ascribes
about 3.8 percent of California’s total NOX
emissions to cropland soils. Soil NOX Study, p. 1.
The commenters did not attempt to further compare
the model results of the Soil NOX Study with the
emissions inventory used in the California
Transport Plan (based on the initial CSAPR Update
modeling) nor the CSAPR Update modeling, upon
which the EPA’s proposed rulemaking was based.
Notwithstanding, the proportion of CARB’s
cropland NOX emissions estimates appear to fall in
a similar scale to those modeled for the EPA’s
CSAPR Update rule.
26 Trousdell, et al., ‘‘Observing entrainment
mixing, photochemical ozone production, and
regional methane emissions by aircraft using a
simple mixed-layer framework,’’ Atmospheric
Chemistry and Physics. 16, 15433–15450 (2016).
25 The
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literature suggesting that soil NOX
emissions could be significantly
underestimated in current inventories
and possibly increase California’s total
NOX emissions by 20 to 51 percent.27
The EPA acknowledges the value that
studies of this kind contribute towards
a better understanding of soil NOX
emissions from California. However, the
quantification of such emissions is
currently uncertain, as described below,
and would require further field research
to substantiate. The commenters did not
address the uncertainties expressed in
the study and did not consider other
important analytical aspects of interstate
transport of ozone.
First, the study acknowledges that a
limited number of surface
measurements were available for
purposes of comparing the model
results and, where observations exist,
there is a large range in observed values
due to varying soil conditions (e.g.,
relating to temperature, moisture,
fertilizer application, etc.). The authors
acknowledge the difficulty in comparing
the model results to the observations
and note the need for more field
measurements.28 Second, there was a
significant degree of uncertainty in the
aircraft estimates of NOX emissions over
the San Joaquin Valley (190 tnpd plus
or minus 130 tnpd, which equates to
plus or minus 68 percent). Further
research would be needed to determine
whether these higher levels of soil NOX
emissions over California and elsewhere
are accurate and reliable before updates
are included in air quality modeling to
support regulatory decisions.29
Furthermore, in the EPA’s proposed
rulemaking, we described the rationale
for our disagreement with CARB’s
assertions in the California Transport
Plan that California’s contributions to
ozone levels in the Denver area were
overestimated, while acknowledging
that the future research that CARB
suggests to better characterize ozone
transport from California to other states
could prove valuable.30 In this response,
27 Id.
at 1.
at 5.
29 Technical comments have been published in
response to the Soil NOX Study that present
additional uncertainties (with respect to the
calculations used) in the Soil NOX Study and
recommend supplemental data that could be
released to allow for an improved assessment of the
study. Maaz, et al., ‘‘Inconsistencies undermine the
conclusion that agriculture is a dominant source of
NOX in California,’’ Science Advances, September
12, 2018. As these technical comments are
copyrighted, they are available in hard copy as part
of the docket of this rulemaking; see the ADDRESSES
section of this action for viewing information. They
are also publicly available at: https://
advances.sciencemag.org/content/4/9/eaat4706?
intcmp=trendmd-adv.
30 83 FR 5375, 5380 (February 7, 2018).
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28 Id.
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we disagree with the commenter that
California’s contributions to such ozone
levels were underestimated, while
similarly acknowledging the value of
further research to better characterize
California’s NOX emissions. In both
cases, however, we assert that the
prospect of future research that might
better quantify California’s emissions or
their effect on other states’ ozone levels
does not itself undermine the technical
adequacy of the EPA’s current modeling
for the 2008 ozone NAAQS. We reaffirm
that the CSAPR Update modeling,
including its emissions inventory bases,
and our analysis with respect to
California based on that modeling
adequately estimate the interstate
transport of ozone from California to
downwind states.
In sum, the soil NOX emissions used
in the CSAPR Update modeling, upon
which our evaluation of the California
Transport Plan relies for the 2008 ozone
NAAQS, were based on the BEIS, which
incorporates prior research on soil NOX
as noted above. While the Soil NOX
Study suggests that California’s soil
NOX emissions may be underestimated,
they have not been adequately
quantified and verified to a sufficient
degree to replace the emissions
inventories that were part of the
analytical basis of the EPA’s proposal to
approve California Transport Plan for
the 2008 ozone NAAQS, nor to warrant
re-running the ozone transport
modeling. Furthermore, the CSAPR
modeling and our proposed finding did
indicate that California is linked to
downwind receptors, and therefore we
presented a general assessment of costeffective controls that can be employed
to reduce emissions from sources in
California.
The EPA therefore disagrees that it
has failed to consider an important
aspect of the interstate transport
problem in violation of the Supreme
Court’s holding in State Farm. We
affirm that the EPA has considered the
multiple important aspects of interstate
transport of ozone from California to
other states, as described in our
proposed rulemaking and in this final
rule’s response to comments. These
aspects include, but are not limited to,
consideration of measured and modeled
ambient ozone concentrations,
measured and estimated NOX and VOC
emissions inventories for California and
the continental U.S., application of state
of the science modeling tools for
regional air pollution analysis and
appropriate model validation, existing
and planned emission control regimes,
and meteorology. Furthermore, we have
considered the commenter’s arguments
with respect to California’s soil NOX
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65099
emissions and disagree that the science
of such emissions is quantified and
verified to a sufficient degree to warrant
a new analysis of interstate transport
from California to other states for the
2008 ozone NAAQS.
Comment #2: The commenter states
that the ozone transport analysis in the
California Transport Plan is flawed by
failing to consider whether soil NOX
emissions from California are
adequately controlled. Specifically, the
commenter states that the EPA failed to
consider whether California has rules to
limit NOX via agricultural management
practices, whether such rules are in the
California SIP, and whether such rules
are adequate. The commenter does not
believe that such rules are in place.
Response #2: We disagree with the
commenter’s assertion that the
California Transport Plan should have
examined whether soil NOX emissions
are subject to control and whether such
controls are adequate for purposes of the
interstate transport requirements for the
2008 ozone NAAQS. This flows from
our considerations expressed in
Response #1 of this final rule. We do not
consider the Soil NOX Study alone to be
sufficient to compel replacement of the
emissions inventories that were the
analytical bases of the EPA’s proposal,
particularly given the study’s wide
range of suggested soil NOX emission
increases (20 to 51 percent for
California) and the large uncertainty in
the model results.
Soil NOX emissions occur across
California’s wide range of ecological
regions 31 and NOX emissions from
agricultural regions in the State
represent a subset of the statewide
annual soil NOX estimate. Within the
agricultural regions, the amount of soil
NOX emitted varies based on
agricultural practices employed (e.g.,
irrigation; method, timing, and amount
of fertilizer application; etc.), crop type,
temperature, and other factors.
Additionally, soil NOX is not directly
emitted (e.g., nitrifying bacteria in the
soil convert ammonium from various
sources into NOX, some of which is
emitted into the atmosphere) and
involves numerous natural emissions
sources and processes. Therefore, the
production of NOX in the soil is quite
complex and inherently difficult to
estimate and model.
In addition, the commenter did not
provide examples or recommendations
of alternative agricultural practices that
might reduce soil NOX emissions in
California. Even if there were known
31 A map of California’s ecological regions is
available at: https://www.epa.gov/eco-research/
ecoregion-download-files-state-region-9.
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alternative practices, it may prove
difficult to estimate the effect of those
potential controls given the complexity
of soil NOX production. Given the
complexity in estimating and modeling
soil NOX emissions, the indirect and
partially natural source of the
emissions, the absence of specific
alternative measures that could be
implemented to reduce soil NOX
emissions, and the uncertainty in the
effectiveness of potential emission
controls, the EPA concludes that there
is not sufficient information available at
this time to warrant an evaluation of
potential control of soil NOX emissions
in California for purposes of interstate
transport prongs 1 and 2 for the 2008
ozone NAAQS.
Therefore, we reaffirm that our
approach of evaluating California’s
largest sources of NOX emissions and
the control measures for such sources,
including mobile sources (70 percent of
the projected 2017 emissions inventory)
and stationary point sources (15 percent
of the inventory, including EGUs and
non-EGU sources), is a reasonable
means for assessing whether California
has satisfied the interstate transport
requirements of CAA section
110(a)(2)(D)(i)(I) with respect to the
2008 ozone NAAQS.
Comment #3: Lastly, the commenter
asserts that measures to control NOX
emissions from cropland soils will bring
economic, ecosystem, and human health
co-benefits to rural California, per the
recent study. On this basis, the
commenter disagrees that the EPA lacks
discretionary authority under Executive
Order 12898 to address disproportionate
human health or environmental effects
and highlights the San Joaquin Valley as
an area with many communities that
suffer environmental injustice. The
commenter states that the California
Transport Plan should include measures
to control NOX emissions from
agricultural soils to reduce pollution in
such communities, consistent with
Executive Order 12898.
Response #3: We disagree that the
EPA has discretionary authority in this
rulemaking under Executive Order
12898 to address any disproportionate
human health or environmental effects
in rural California. First, Executive
Order 12898 applies only to federal
agency actions that invoke certain
federal requirements, such as the
National Environmental Policy Act or
CAA section 309, and it does not apply
where the EPA is merely approving a
state submission as meeting basic
requirements of the CAA. Second, this
rulemaking concerns the interstate
transport of ozone from California to
other states under CAA section
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110(a)(2)(D)(i)(I), rather than the effect
of California’s NOX emissions on
communities within California. Thus,
the commenters suggestion that
California should control NOX
emissions from cropland soils to reduce
pollution that may affect communities
in California is outside the scope of this
rulemaking. For these reasons,
Executive Order 12898 is not applicable
to this action.
III. EPA Action
We have reviewed the California
Transport Plan for the 2008 ozone, 2006
PM2.5, 2012 PM2.5, and 2010 SO2
NAAQS using step-wise processes.
Based on this review and additional
analyses conducted by the EPA to verify
and supplement the California
Transport Plan, and consistent with
CAA section 110(a)(2)(D)(i)(I) and EPA
guidance with respect to interstate
transport for these NAAQS, we find that
California will not significantly
contribute to nonattainment, or interfere
with maintenance, of the 2008 ozone,
2006 PM2.5, 2012 PM2.5, and 2010 SO2
NAAQS in any other state. No
comments were submitted that change
our assessment of the California
Transport Plan as described in our
proposed rulemaking. Therefore, as
authorized in section 110(k)(3) of the
Act, the EPA is fully approving the
California Transport Plan into the
California SIP for the requirements of
CAA section 110(a)(2)(D)(i)(I) for these
NAAQS.
In addition, for the 2006 PM2.5 and
2008 ozone NAAQS, the EPA had
previously found that California failed
to submit the required SIP revisions
addressing interstate transport prongs 1
and 2 by certain dates.32 Those actions
triggered the obligation for the EPA to
promulgate a federal implementation
plan (FIP) for these requirements unless
the State submitted and the EPA
approved a SIP submission that
addresses the two prongs. As the EPA is
fully approving the California Transport
Plan for these two NAAQS, this final
rule also removes the obligation for the
EPA to promulgate such FIPs.
IV. 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, the EPA’s role is to
32 79 FR 63536 (October 24, 2014) for the 2006
PM2.5 NAAQS; and 80 FR 39961 (July 13, 2015) for
the 2008 ozone NAAQS.
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approve state choices, provided that
they meet the criteria of the Clean Air
Act. Accordingly, this 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 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 an Executive Order 13771 (82
FR 9339, February 2, 2017) regulatory
action because SIP approvals are
exempted 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 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 is not approved
to apply on any Indian reservation land
or in any other area where the 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).
E:\FR\FM\19DER1.SGM
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Federal Register / Vol. 83, No. 243 / Wednesday, December 19, 2018 / Rules and Regulations
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. The 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 Clean
Air Act, petitions for judicial review of
this action must be filed in the United
States Court of Appeals for the
appropriate circuit by February 19,
2019. 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 section
307(b)(2).)
List of Subjects in 40 CFR Part 52
Environmental protection, Air
pollution control, Ammonia,
Incorporation by reference,
Intergovernmental relations, Nitrogen
dioxide, Ozone, Particulate matter,
Reporting and recordkeeping
requirements, Sulfur dioxide, Volatile
organic compounds.
Identification of plan—in part.
*
*
*
*
*
(c) * * *
(512) The following plan was
submitted on January 19, 2016, by the
Governor’s Designee.
(i) [Reserved].
(ii) Additional materials.
(A) California Air Resources Board
(CARB).
(1) ‘‘California Infrastructure State
Implementation Plan (SIP) Revision,
Clean Air Act Section 110(a)(2)(D),’’
adopted December 17, 2015,
(‘‘California Transport Plan’’).
■ 3. Section 52.283 is amended by
adding paragraphs (c)(3), (d)(3), and
(g)(3) to read as follows:
§ 52.283
Interstate Transport.
*
*
*
*
*
(c) * * *
(3) The requirements of CAA section
110(a)(2)(D)(i)(I) regarding significant
contribution to nonattainment of the
2006 PM2.5 NAAQS and 2012 PM2.5
NAAQS in any other state and
interference with maintenance of the
2006 PM2.5 NAAQS and 2012 PM2.5
NAAQS by any other state.
*
*
*
*
*
(d) * * *
(3) The requirements of CAA section
110(a)(2)(D)(i)(I) regarding significant
contribution to nonattainment of the
2008 ozone NAAQS in any other State
and interference with maintenance of
the 2010 ozone NAAQS by any other
State.
*
*
*
*
*
(g) * * *
(3) The requirements of CAA section
110(a)(2)(D)(i)(I) regarding significant
contribution to nonattainment of the
2010 SO2 NAAQS in any other State and
interference with maintenance of the
2010 SO2 NAAQS by any other State.
[FR Doc. 2018–27477 Filed 12–18–18; 8:45 am]
Dated: November 30, 2018.
Deborah Jordan,
Acting Regional Administrator, Region IX.
BILLING CODE 6560–50–P
Part 52, Chapter I, Title 40 of the Code
of Federal Regulations is amended as
follows:
ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Part 271
PART 52—APPROVAL AND
PROMULGATION OF
IMPLEMENTATION PLANS
[EPA–R08–RCRA–2018–0554; FRL–9986–
24–Region 8]
1. The authority citation for part 52
continues to read as follows:
North Dakota: Final Authorization of
State Hazardous Waste Management
Program Revisions
■
amozie on DSK3GDR082PROD with RULES
§ 52.220
Authority: 42 U.S.C. 7401 et seq.
Subpart F—California
2. Section 52.220 is amended by
adding paragraph (c)(512) to read as
follows:
■
VerDate Sep<11>2014
16:29 Dec 18, 2018
Jkt 247001
Environmental Protection
Agency (EPA).
ACTION: Direct final rule.
AGENCY:
North Dakota has applied for
final authorization of a revision to its
SUMMARY:
PO 00000
Frm 00027
Fmt 4700
Sfmt 4700
65101
hazardous waste program under the
Resource Conservation and Recovery
Act (RCRA). The revision has two parts,
both of which relate directly to the
creation of the North Dakota Department
of Environmental Quality (NDDEQ) by
the North Dakota Legislature, and the
impending transfer of authority, power,
and duties relating to environmental
quality from the North Dakota
Department of Health (NDDH) to the
NDDEQ. The first part of the program
revision is the complete transfer of all
hazardous waste program rules from
Title 33 Article 24 of the North Dakota
Administrative Code (NDAC) to NDAC
Title 33.1 Article 24. The second part is
replacing all references to NDDH with
NDDEQ. No other changes are being
made to the hazardous waste program
rules in this revision. The EPA has
reviewed the application and
determined that North Dakota’s
hazardous waste program revision
satisfies all of the requirements
necessary to qualify for final
authorization. The EPA is authorizing
the state program revision through this
direct final rule. The EPA is publishing
this rule without prior proposal because
the Agency views this as a
noncontroversial action and does not
anticipate adverse comments. However,
in the proposed rules section of this
Federal Register, the EPA is publishing
a separate document that will serve as
a proposal to authorize the revision
should the Agency receive adverse
comment. Unless the EPA receives
adverse written comments during the
review and comment period, the
decision to authorize North Dakota’s
hazardous waste program revision will
take effect as provided below.
DATES: This final rule is effective on
March 15, 2019, unless the EPA receives
adverse written comment by January 18,
2019. Should the EPA receive such
comments, it will publish a timely
document either: Withdrawing the
direct final publication or affirming the
publication and responding to
comments.
ADDRESSES: The EPA has established a
docket for this action under Docket ID
No. EPA–R08–RCRA–2018–0554. All
documents in the docket are listed on
the https://www.regulations.gov website.
Although listed in the index, some
information is not publicly available,
e.g., CBI or other information, the
disclosure of which is restricted by
statute. Certain other material, such as
copyrighted material, is not placed on
the internet and will be publicly
available only in hard copy form.
Publicly available docket materials are
available either electronically through
E:\FR\FM\19DER1.SGM
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]]>Agencies
[Federal Register Volume 83, Number 243 (Wednesday, December 19, 2018)]
[Rules and Regulations]
[Pages 65093-65101]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-27477]
-----------------------------------------------------------------------
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R09-OAR-2017-0177; FRL-9987-97-Region 9]
Approval and Promulgation of Air Quality State Implementation
Plans; California; Interstate Transport Requirements for Ozone, Fine
Particulate Matter, and Sulfur Dioxide
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: The Environmental Protection Agency (EPA) is finalizing
approval of a State Implementation Plan (SIP) submission from the State
of California regarding certain interstate transport requirements of
the Clean Air Act (CAA or ``Act''). This submission addresses the 2008
ozone national ambient air quality standards (NAAQS), the 2006 fine
particulate matter (PM2.5) and 2012 PM2.5 NAAQS,
and the 2010 sulfur dioxide (SO2) NAAQS. The interstate
transport requirements under the CAA consist of several elements; this
final rule pertains only to significant contribution to nonattainment
and interference with maintenance of the NAAQS in other states.
DATES: This final rule is effective on January 18, 2019.
ADDRESSES: The EPA has established a docket for this action under
Docket ID No. EPA-R09-OAR-2017-0177. All documents in the docket are
listed on the https://www.regulations.gov website. Although listed in
the index, some information is not publicly available, e.g.,
Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. Certain other material, such as
copyrighted material, is not placed on the internet and will be
publicly available only in hard copy form. Publicly available docket
materials are available through https://www.regulations.gov, or please
contact the person identified in the FOR FURTHER INFORMATION CONTACT
section for additional availability information.
FOR FURTHER INFORMATION CONTACT: Rory Mays, Air Planning Office (AIR-
2), EPA Region IX, (415) 972-3227, mays.rory@epa.gov.
SUPPLEMENTARY INFORMATION: Throughout this document, ``we'', ``us'' and
``our'' refer to the EPA.
Table of Contents
I. Proposed Action
A. Evaluation for the 2008 Ozone NAAQS
B. Evaluation for the 2006 PM2.5 and 2012
PM2.5 NAAQS
C. Evaluation for the 2010 SO2 NAAQS
II. Public Comments and EPA Responses
III. EPA Action
IV. Statutory and Executive Order Reviews
I. Proposed Action
The California Air Resources Board (CARB) submitted the
``California Infrastructure State Implementation Plan (SIP) Revision,
Clean Air Act Section 110(a)(2)(D)'' on January 19, 2016 (``California
Transport Plan'' or ``Plan'').\1\ This Plan addresses interstate
transport for the 2008 ozone, 2006 PM2.5, 2012
PM2.5, and 2010 SO2 NAAQS.\2\ On February 7,
2018, the EPA proposed to approve the California Transport Plan into
the California SIP because we determined that it complies with the
relevant CAA requirements.\3\ Our proposed action contains more
information on the California Transport Plan and our evaluation. We
summarize the key points of our proposed rulemaking and evaluation in
this final rule.
---------------------------------------------------------------------------
\1\ Letter dated January 19, 2016, from Richard W. Corey,
Executive Officer, CARB to Jared Blumenfeld, Regional Administrator,
Region 9, EPA.
\2\ The 2008 ozone NAAQS include primary and secondary 8-hour
ozone NAAQS of 0.075 parts per million (ppm), 73 FR 16436 (March 27,
2008). The 2006 PM2.5 NAAQS include primary and secondary
24-hour NAAQS for PM2.5 of 35 micrograms per cubic meter
([micro]g/m\3\), 71 FR 61144 (October 17, 2006). The 2012
PM2.5 NAAQS include a primary annual PM2.5
NAAQS of 12.0 [mu]g/m\3\, 78 FR 3086 (January 15, 2013). The 2010
SO2 NAAQS include a primary 1-hour SO2 NAAQS
of 75 parts per billion (ppb), 75 FR 35520 (June 22, 2010).
\3\ 83 FR 5375.
---------------------------------------------------------------------------
Sections 110(a)(2)(D)(i)(I)-(II) of the CAA require SIPs to include
provisions prohibiting any source or other type of emissions activity
in one state from emitting any air pollutant in amounts that will
contribute significantly to nonattainment, or interfere with
maintenance, of the NAAQS, or interfere with measures required to
prevent significant deterioration of air quality or to protect
visibility in any other state. This final rule addresses the
[[Page 65094]]
two requirements under section 110(a)(2)(D)(i)(I), which we refer to as
prong 1 (significant contribution to nonattainment of the NAAQS in any
other state) and prong 2 (interference with maintenance of the NAAQS in
any other state).\4\ The EPA refers to SIP revisions addressing the
requirements of section 110(a)(2)(D)(i)(I) as ``good neighbor SIPs'' or
``interstate transport SIPs.''
---------------------------------------------------------------------------
\4\ The remaining interstate and international transport
requirements of CAA section 110(a)(2)(D) for the 2008 ozone, 2006
PM2.5, 2012 PM2.5, and 2010 SO2
NAAQS for California have been addressed in prior State submissions
and EPA rulemakings. 81 FR 18766 (April 1, 2016). Specifically, this
includes the section 110(a)(2)(D)(i)(II) requirements relating to
interference with measures required to be included in the applicable
implementation plan for any other state under part C to prevent
significant deterioration of air quality (prong 3) or to protect
visibility (prong 4), and the section 110(a)(2)(D)(ii) requirements
relating to interstate and international pollution abatement.
---------------------------------------------------------------------------
In addition to our evaluation of the California Transport Plan with
respect to transport of air pollution to other states, we considered
transport to the Morongo Band of Mission Indians (``Morongo'') and the
Pechanga Band of Luise[ntilde]o Indians (``Pechanga''), given their
regulatory monitoring for certain pollutants and comments during the
EPA's rulemaking on California's interstate transport SIP for the 1997
ozone and 1997 PM2.5 NAAQS. Based on our review of the
ambient air quality data of Morongo and Pechanga and the emission
control regimes of the South Coast Air Quality Management District
(AQMD) for stationary sources and of CARB for mobile sources, as
described in the EPA's memo to the docket,\5\ the EPA proposed to find
that California adequately prohibits the emission of air pollutants in
amounts that will significantly contribute to nonattainment, or
interfere with maintenance, of the 2008 ozone, 2006 PM2.5,
2012 PM2.5, and 2010 SO2 NAAQS in the Morongo and
Pechanga reservations. The EPA offered consultation with each tribe at
the time of the proposal; neither tribe requested such consultation.\6\
---------------------------------------------------------------------------
\5\ Memorandum of January 2018 from Rory Mays, Air Planning
Office, Air Division, Region IX, EPA, ``Interstate Transport for the
2008 ozone, 2006 PM2.5, 2012 PM2.5, and 2010
SO2 NAAQS and the Morongo Band of Mission Indians and the
Pechanga Band of Luise[ntilde]o Indians.''
\6\ See, e.g., email dated February 27, 2018 from Kelcey
Stricker, Environmental Director, Pechanga Band of Luise[ntilde]o
Mission Indians to Rory Mays, Air Planning Office, U.S. EPA Region
IX, indicating that Pechanga did not see the need to consult. The
EPA did not receive a request for consultation or a comparable email
from the Morongo Band of Mission Indians.
---------------------------------------------------------------------------
A. Evaluation for the 2008 Ozone NAAQS
In our proposed rulemaking the EPA agreed with the conclusion of
the California Transport Plan that California meets the CAA
requirements for interstate transport prongs 1 and 2 for the 2008 ozone
NAAQS. However, our rationale differed from that presented by CARB. The
analysis in the California Transport Plan relies primarily on CARB's
conclusion that the ozone transport linkages are uncertain and
therefore no significant contribution or interference with maintenance
has been demonstrated. The EPA's evaluation finds that the transport
linkages are adequately quantified (and uncertainties sufficiently
addressed) and that California's emission control programs adequately
address the transport requirements.
The EPA presented the various elements of our evaluation that led
to this conclusion.\7\ The EPA first explained that it approached its
evaluation considering the four-step framework for evaluating regional
ozone transport that has been developed through several prior regional
EPA rulemakings. This framework evaluates downwind air quality (step
1), upwind state linkages (step 2), and various cost and air quality
factors (step 3) to identify whether a state will significantly
contribute to nonattainment or interfere with maintenance of the NAAQS
in another state and to implement any necessary emission reductions
(step 4). We discussed the EPA's modeling for the Cross-State Air
Pollution Rule (CSAPR) Update rule (``CSAPR Update''),\8\ which
identified regulatory monitors throughout the continental U.S. that
were expected to exceed the NAAQS in 2017 based on both projected
average design values and monitored data as ``nonattainment receptors''
(i.e., not expected to attain) and those that may have difficulty
maintaining the NAAQS, taking into account historic variability in air
quality, as ``maintenance receptors,'' and estimated the contribution
of other states to the ozone levels at each of these receptors. The
analytic year of 2017 was selected since it corresponds to the
attainment year prior to the mid-2018 attainment deadline for 2008
ozone NAAQS nonattainment areas classified as Moderate.
---------------------------------------------------------------------------
\7\ For discussion of our general evaluation approach and our
specific evaluation with respect to the 2008 ozone NAAQS, please see
sections II.A and II.B of our proposed rulemaking preamble. 83 FR
5375 (February 7, 2018).
\8\ 81 FR 74504 (October 26, 2016).
---------------------------------------------------------------------------
We addressed CARB's assertions regarding ozone transport modeling
uncertainties (relating to a prior, similar iteration of the EPA's
ozone transport modeling) for identifying nonattainment and maintenance
receptors in 2017 and linkages from California to downwind receptors,
and discussed the contrast that CARB draws between ozone transport in
the eastern versus western U.S.
Based on our analysis, we proposed to find that California is
linked to three maintenance receptors in the Denver, Colorado area.
This conclusion was based on a combination of factors: (1) The EPA's
projection that California emissions would contribute above 1 percent
of the 2008 ozone NAAQS at each of the three receptors (1.1 to 2.6
percent), (2) other states also contribute above 1 percent of the NAAQS
to these receptors, and (3) the average interstate contribution to
ozone concentrations from all states upwind of these receptors was both
considerable (9.2 to 9.4 percent of the projected ozone design values)
and comparable to collective contributions from upwind states to
receptors in Texas as evaluated in the CSAPR Update. Accordingly, we
proposed that a 1 percent threshold is appropriate as an air quality
threshold to determine whether California is ``linked'' to the three
maintenance receptors in the Denver area for the 2008 ozone NAAQS.
Our proposed finding that California is linked to the three Denver
area receptors prompted further inquiry into whether the contributions
would interfere with maintenance at the receptors and whether there are
cost-effective controls that can be employed to reduce emissions. To do
so, we presented a general assessment of the emission sources in
California, including mobile and stationary emission sources. We
proposed to find that control measures in the California SIP for mobile
sources, large electricity generating units (EGUs), and large non-EGU
sources (e.g., cement plants and oil refineries), adequately prohibit
the emission of air pollution in amounts that will interfere with
maintenance of the 2008 ozone NAAQS at the identified receptors in the
Denver area.
We discussed California's mobile source measures, which are
primarily adopted and implemented by CARB, and stationary source
measures, which are primarily adopted and implemented by California's
35 local air districts. For the latter, beyond the measures described
in the California Transport Plan, we also considered stationary
[[Page 65095]]
source control measures for EGUs, consistent with the controls analysis
for the CSAPR and CSAPR Update rulemakings,\9\ and examples of
stationary source control measures for the largest non-EGU sources in
the State.
---------------------------------------------------------------------------
\9\ 76 FR 48208 (August 8, 2011) and 81 FR 74504 (October 26,
2016), respectively.
---------------------------------------------------------------------------
We noted that California mobile sources account for approximately
70 percent of the projected 2017 nitrogen oxide (NOX)
emissions and that CARB has established a comprehensive program to
control and reduce mobile source emissions within the state. The EPA
has approved many of CARB's mobile source regulations as part of the
California SIP, including regulations establishing standards and other
requirements relating to emissions from cars, light- and medium-duty
trucks, heavy-duty trucks, commercial harbor craft, mobile cargo
handling equipment, marine engines and boats, and off-highway
recreational vehicles. To support and enhance these emissions
standards, we also noted that CARB has established specific gasoline
and diesel fuel requirements, and the California Bureau of Automotive
Repair has established a vehicle emissions and inspection (i.e., ``smog
check'') program.
With respect to stationary and area emission sources, we noted that
the California SIP has hundreds of rules that limit the emissions of
NOX and volatile organic compounds (VOCs) and that many of
these rules were developed by local air districts to reduce ozone
concentrations in response to the prior 1979 1-hour ozone and 1997 8-
hour ozone NAAQS.
For EGUs producing greater than 25 megawatts of electricity,
including non-fossil fuel EGUs, we described how California's statewide
NOX emissions rate is very low (0.0097 pounds of
NOX per million British thermal units in 2018) and ranks as
the 47th lowest out of the 48 contiguous states and Washington, DC for
which the EPA performed power sector modeling in the context of the
CSAPR Update. We found that California produces electricity very
efficiently in terms of NOX emissions and is therefore
unlikely to have significant, further NOX reductions
available from the EGU sector at reasonable cost.
In investigating the potential for further NOX emissions
reductions from EGUs, we found that additional NOX
reductions from EGUs in California would cost more than three times the
amount that the EPA determined to be cost-effective to partially
address ozone transport obligations in the eastern U.S. under the CSAPR
Update (i.e., reductions expected above $5,000 per ton of
NOX in California versus a cost-effective control level of
$1,400 per ton in the CSAPR Update rulemaking for 22 eastern states).
Further, we noted that the largest collection of EGU facilities
emitting over 100 tons per year (tpy) of NOX, per the 2011
National Emissions Inventory, are found in the San Joaquin Valley, Bay
Area, and South Coast air districts and are subject to district rules
that limit NOX emissions and have been approved into the
California SIP.
For non-EGU stationary sources, we found that they emitted 6.7
times more NOX than EGUs in California in 2011. Of these
sources, 19 emitted over 500 tpy of NOX, including Portland
cement plants, petroleum refineries, and several other source types,
and accounted for two thirds of the NOX emissions from
California stationary sources that emitted over 100 tpy in 2011 and 5.2
percent of the total 2011 NOX inventory for California.
These 19 sources are in the Bay Area, Kern County, Mojave Desert, San
Joaquin Valley, and South Coast air districts and, overall, are subject
to rules that limit NOX emissions and have been approved
into the California SIP. For the small number of large non-EGU sources
that are either subject to NOX control measures that have
not been submitted for approval into the California SIP, or fall
outside the geographic jurisdiction of the applicable district rules,
we found that further emission controls would be unlikely to reduce any
potential impact on downwind states' air quality because such sources
comprise no more than 0.8 percent of the total NOX emitted
in California in 2011.
In sum, on the strength of CARB and the local air districts'
emission control programs, especially for mobile and stationary sources
of NOX, we proposed that the California SIP adequately
prohibits the emission of air pollutants in amounts that will
significantly contribute to nonattainment, or interfere with
maintenance, of the 2008 ozone NAAQS in any other state. The EPA also
noted that recent modeling shows that by the 2023 ozone season the
receptors identified in Denver are projected to be ``clean,'' i.e.,
both the average and maximum design values are projected to be below
the level of the 2008 ozone NAAQS.\10\
---------------------------------------------------------------------------
\10\ Memorandum dated October 27, 2017 from Stephen D. Page,
Director, EPA Office of Air Quality Planning and Standards, to
Regional Air Division Directors, Regions 1-10. Available at: https://www.epa.gov/sites/production/files/2017-10/documents/final_2008_o3_naaqs_transport_memo_10-27-17b.pdf.
---------------------------------------------------------------------------
B. Evaluation for the 2006 PM2.5 and 2012 PM2.5 NAAQS
The EPA proposed to approve the California Transport Plan for the
CAA requirements for interstate transport prongs 1 and 2 for the 2006
PM2.5 and 2012 PM2.5 NAAQS. First, we discussed
our evaluation of CARB's identification of nonattainment and
maintenance receptors in western states based on data presented in the
California Transport Plan as well as the EPA's analysis of 2009-2013
24-hour and annual PM2.5 design values. Based on that
evaluation, we presented modified lists of such receptors that largely
follow the lists of receptors in the California Transport Plan.
For the 2006 24-hour PM2.5 NAAQS, we derived a list of
18 potential nonattainment receptors and three potential maintenance
receptors within 11 western states (excluding California) \11\ that
accounted for the information presented in the California Transport
Plan and ambient air quality and emissions data that were common to our
evaluation of both the 24-hour and annual NAAQS. We also presented the
24-hour PM2.5 design values for 2014-2016 at each identified
receptor.
---------------------------------------------------------------------------
\11\ For purposes of this rulemaking, ``western states'' refers
to the states of Arizona, California, Colorado, Idaho, Montana,
Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming.
---------------------------------------------------------------------------
For the 2012 annual PM2.5 NAAQS, we did not find that
there would be any potential nonattainment receptors and we identified
two potential maintenance receptors, one in Idaho and one in
Pennsylvania. To do so, we relied on photochemical modeling results
presented in the EPA's informational memo on interstate transport for
the 2012 PM2.5 NAAQS (``2012 PM2.5 NAAQS
Transport Memo''), which projected annual PM2.5 design
values for 2017 and 2025 at each regulatory PM2.5 monitor in
the continental U.S.\12\ We used those results to evaluate projected
air quality in 2021, which corresponds to the attainment deadline for
2012 PM2.5 NAAQS nonattainment areas classified as Moderate.
We also addressed some differences in the receptors identified by CARB
and those identified by the EPA and considered the annual
PM2.5 design values for 2014-2016 at the potential
maintenance receptors identified in the EPA's 2012 PM2.5
NAAQS Transport Memo.
---------------------------------------------------------------------------
\12\ 2012 PM2.5 NAAQS Transport Memo, Table 1, 5.
Available at https://www.epa.gov/pm-pollution/information-interstate-transport-good-neighbor-provision-2012-fine-particulate-matter.
---------------------------------------------------------------------------
We then discussed California emissions of PM2.5 and its
precursors, California's regulations to limit such emissions, and the
emissions trends
[[Page 65096]]
resulting from such regulations. We discussed California's control
measures before our more specific discussion of interstate transport
prongs 1 and 2 for each NAAQS because such discussion provided a common
basis for evaluating the California emissions component of CARB's
weight of evidence analysis. For three PM2.5 precursors
pollutants, we incorporated our evaluation of California's emissions
and regulatory programs for NOX and VOC (for the 2008 ozone
NAAQS) and oxides of sulfur (SOX) (for the 2010
SO2 NAAQS).\13\ For directly-emitted PM2.5, we
affirmed that many of California's measures limit the emission of
particulate matter and have been approved into the California SIP.
These include the State's mobile source emission standards and test
procedures for heavy-duty engines and vehicles, passenger cars, light
duty trucks, and medium duty vehicles; in-use diesel standards for
heavy-duty trucks, buses, drayage trucks, and off-road vehicles; and
inspection and maintenance programs, as well as air district stationary
source measures for combustion sources of PM2.5, such as
open burning, refineries, and cement plants, and dust sources of
PM2.5, such as fugitive dust from roads and agricultural
operations.
---------------------------------------------------------------------------
\13\ CARB estimates that SO2 comprises 97% of the
state-wide SOX inventory and therefore used California
SOX emissions in its analysis to represent California
SO2 emissions. California Transport Plan, App. C, C-1.
---------------------------------------------------------------------------
We also described trends in California emissions, which have
decreased by substantial amounts (e.g., statewide decreases from 2000
to 2016 of 75 percent direct PM2.5, 66 percent
NOX, 54 percent VOC, and 75 percent SO2) in
response to state and local control measures, as well as federal
measures for sources outside California's regulatory authority.
Based on our review of the state and local measures cited in the
California Transport Plan that limit the emission of PM2.5
and its precursor pollutants and of the applicable California emission
trends, which are generally decreasing, we agreed with CARB's general
conclusions regarding interstate transport of PM2.5: That
California emissions from stationary sources are subject to stringent
limits for direct PM2.5 and its precursors (e.g.,
NOX and SOX); that California has a long history
of reducing emissions through motor vehicle and fuel standards; and
that state and local measures will continue to reduce the potential for
California emissions to contribute significantly to nonattainment, or
interfere with maintenance, of the 2006 24-hour PM2.5 or
2012 annual PM2.5 NAAQS in any other state.
Building on the identification of potential nonattainment and
maintenance receptors and our discussion of California emissions, we
presented the EPA's weight of evidence analysis to address the CAA
requirements, which affirmed CARB's weight of evidence analysis for the
2006 24-hour PM2.5 and 2012 annual PM2.5 NAAQS.
We prepared a Technical Support Document (TSD) containing our more
detailed analysis of interstate transport for the 2006 24-hour
PM2.5 NAAQS (``EPA's PM2.5 Transport TSD''),
which was also relevant for our evaluation of the 2012 annual
PM2.5 NAAQS.\14\
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\14\ ``EPA Evaluation of the California Interstate Transport
Plan (2006 PM2.5 NAAQS), Technical Support Document,''
EPA, Region IX, January 2018.
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For interstate transport prongs 1 and 2 for the 2006 24-hour
PM2.5 NAAQS, we summarized our evaluation of the areas
encompassing the 18 nonattainment receptors, grouping them into three
geographic bins (i.e., Arizona, the Northern Rocky Mountains, and Utah)
based on the nature of the emission sources affecting the receptors,
and the areas encompassing the three maintenance receptors, grouping
them by the two relevant states (Montana and Utah).
For each receptor area we described our review of the information
compiled and presented in the California Transport Plan, including
distance of relevant receptors from California; intervening terrain;
potential wildfire effects; chemical speciation data; local topography;
the effect of local emission sources, particularly residential wood
burning and, in certain cases, other sources (e.g., mobile sources,
agricultural activities), on wintertime exceedances; and regional
background levels represented by ambient 24-hour PM2.5 data
from Interagency Monitoring of Protected Visual Environments (IMPROVE)
monitoring sites. We reviewed California's emissions and emission
control programs for PM2.5 and its precursors, especially
for NOX and SOX, and concluded that California
has an extensive and effective program for limiting emissions of such
pollutants. Thus, we proposed that California will not significantly
contribute to nonattainment or interfere with maintenance of the 2006
24-hour PM2.5 NAAQS in any western state.
As the California Transport Plan did not evaluate PM2.5
transport to states farther east than Montana, Wyoming, Colorado, and
New Mexico, we evaluated the potential for transport of
PM2.5 and its precursors to states farther east. We did so
by reviewing modeling data from the CSAPR and recent air quality data
to identify the westernmost area in the East \15\ with potential
nonattainment or maintenance receptors, and then comparing California's
likely contributions with the contributions of intervening states that
may significantly contribute to nonattainment or interfere with
maintenance of the NAAQS at the potential nonattainment and maintenance
receptors, respectively.
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\15\ For purposes of the PM2.5 evaluation in this
notice, ``the East'' refers to the 37 states and Washington, DC that
lie east of the states of Montana, Wyoming, Colorado, and New
Mexico. The EPA modeled the contribution of states within the East
to each receptor for CSAPR but did not model the contribution of any
state further west, such as California.
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We concluded that California emission sources will not
significantly contribute to nonattainment or interfere with maintenance
of the 2006 PM2.5 NAAQS at the westernmost nonattainment and
maintenance receptors in the East, which were in Madison County,
Illinois. This was based on the generally improved air quality in the
East since the EPA's analysis in 2011 for CSAPR, which reduced the
number of potential nonattainment or maintenance receptors; the
distance of the Madison County, Illinois receptors from California;
intervening terrain; our analysis of the westernmost states linked to
the Madison receptors and comparison of California emissions; the large
reductions in emissions of PM2.5 and its precursors in
California; and the trend of decreasing 24-hour PM2.5
concentrations at the Madison receptors. As the distance from
California to the other potential eastern nonattainment or maintenance
receptors is even greater, we noted that the expected contribution from
California to 24-hour PM2.5 concentrations at such receptors
would be even smaller and thus not significantly contribute to
nonattainment or interfere with maintenance of the 2006 24-hour
PM2.5 NAAQS in any state farther east than Montana, Wyoming,
Colorado, and New Mexico.
For interstate transport prongs 1 and 2 for the 2012 annual
PM2.5 NAAQS, we agreed with CARB that California will not
significantly contribute to nonattainment, or interfere with
maintenance, of the 2012 annual PM2.5 NAAQS in any other
state and presented our analysis for potential maintenance receptors in
Lemhi and Shoshone counties, Idaho and Allegheny County, Pennsylvania.
[[Page 65097]]
For the potential maintenance receptors in Idaho, we reviewed the
information compiled and presented in the California Transport Plan,
including distance of these monitors from California; intervening
terrain; wildfire effects; local topography; the effect of local
emission sources on wintertime exceedances of the 24-hour NAAQS and the
effect of those exceedances on annual PM2.5 concentrations;
and rural background levels represented by IMPROVE data. We reviewed
California's emissions and emission control programs for
PM2.5 and its precursors, especially for NOX and
SOX, and concluded that California has an extensive and
effective program for limiting emissions of such pollutants. Thus, we
proposed that California will not significantly contribute to
nonattainment or interfere with maintenance of the 2012 annual
PM2.5 NAAQS in Idaho or any western state.
For the potential maintenance receptor in Allegheny County,
Pennsylvania, we concluded that California emission sources will not
interfere with maintenance of the 2012 annual PM2.5 NAAQS.
This was based on our interpolated projection that the Allegheny
monitor will likely be attaining the annual PM2.5 NAAQS in
2021; the distance of this receptor from California; intervening
terrain; the contribution modeling performed for CSAPR; the large
reductions in emissions of PM2.5 and its precursors in
California; and the general trend of decreasing annual PM2.5
concentrations at the Allegheny receptor.
Based on our analysis that there are no nonattainment receptors
outside of California for the 2012 PM2.5 NAAQS, and our
analysis for the maintenance receptors in Idaho and Pennsylvania, we
proposed that California will not significantly contribute to
nonattainment, or interfere with maintenance, of the 2012
PM2.5 NAAQS in any other state.
C. Evaluation for the 2010 SO2 NAAQS
The EPA proposed to approve the California Transport Plan for the
CAA requirements for interstate transport prongs 1 and 2 for the 2010
SO2 NAAQS. We described how our evaluation of SO2
transport required a slightly different approach than our evaluation
for regional pollutants, such as ozone and PM2.5, and more
localized pollutants, like lead, given the universe of SO2
emission sources and physical properties of SO2 in the
atmosphere relative to those other pollutants. In our evaluation we
addressed the air quality, emission sources, and emission trends in the
states bordering California, i.e., Arizona, Nevada, and Oregon. Then we
discussed California's air quality, emissions sources, control
measures, and emission trends with respect to interstate transport
prong 1, followed by discussion of additional California air quality
trends and emission trends with respect to interstate transport prong
2.
We found that monitored 1-hour SO2 levels in Arizona,
Nevada, and Oregon are generally well below 75 ppb; that sources in
these bordering states that emit over 2,000 tpy of SO2 are
located at a distance well beyond a 50-km buffer from California's
borders where emissions from California sources might be expected to
have downwind impacts on air quality; and that the downward
SO2 emission trends in each bordering state reduce the
likelihood of SO2 nonattainment or maintenance issues
appearing in the future.\16\
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\16\ This final approval of the California Transport Plan for
the 2010 SO2 NAAQS under CAA section 110(a)(2)(D)(i)(I)
is based on the information contained in the administrative record
for this action and does not prejudge any other future EPA action
that may make other determinations regarding California's air
quality status. Any such future actions, such as area designations
under any NAAQS, will be based on their own administrative records
and the EPA's analyses of information that becomes available at
those times. Future available information may include, and is not
limited to, monitoring data and modeling analyses conducted pursuant
to the EPA's SO2 Data Requirements Rule (80 FR 51052,
August 21, 2015) and information submitted to the EPA by states, air
agencies, and third-party stakeholders such as citizen groups and
industry representatives.
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For interstate transport prong 1, the EPA reviewed the analysis
presented in the California Transport Plan and considered additional
information on ambient SO2 monitoring data, SO2
emission sources and controls, including state measures for mobile
sources and air district measures for large stationary sources, and
emission trends in California. As for Arizona, Nevada, and Oregon,
monitored 1-hour SO2 levels in California are low (most
often below half the level of the 2010 SO2 NAAQS); the 29
SO2 sources in California that emit over 100 tpy of
SO2 are located at a distance well beyond 50 km from
California's borders, the distance where emissions from California
sources might be expected to have downwind impacts on air quality in
bordering states; and California's decreasing SO2 emission
trend each reduce the likelihood of California emitting SO2
in amounts that would adversely affect other states in the future.
Therefore, based on our analysis of SO2 air quality and
emission sources in Arizona, Nevada, and Oregon and our analysis of
SO2 air quality and emissions in California, we proposed
that California will not significantly contribute to nonattainment of
the 2010 SO2 NAAQS in any other state, per the requirements
of CAA section 110(a)(2)(D)(i)(I).
For interstate transport prong 2, the EPA reviewed the analysis
presented in the California Transport Plan and considered additional
information on California air quality trends and emission trends to
evaluate CARB's conclusion that California does not interfere with
maintenance of the 2010 SO2 NAAQS in other states. The EPA's
analysis built on our evaluation of air quality and SO2
emission sources in Arizona, Nevada, and Oregon, and our evaluation for
significant contribution to nonattainment (prong 1) based on the
evidence that we reviewed (i.e., low ambient concentrations of
SO2, large distance of SO2 sources from the
California border, decreasing SO2 emissions, and the
existence of SIP-approved California control measures).
We found that from 2000 to 2015 both ambient SO2
concentrations and SO2 emissions from California's largest
stationary sources have decreased substantially; and that state and
local measures to limit the sulfur content of fuels and limit
SO2 emissions will continue to limit SO2
emissions that might adversely affect other states. Accordingly, we
proposed that California SO2 emission sources will not
interfere with maintenance of the 2010 SO2 NAAQS in any
other state, per the requirements of CAA section 110(a)(2)(D)(i)(I).
II. Public Comments and EPA Responses
The 30-day comment period for the EPA's proposed rulemaking closed
on March 9, 2018. We received four comment letters in response to the
proposed rulemaking. CARB submitted a letter affirming its support for
the EPA's proposed approval.\17\ The Center for Biological Diversity
(CBD) submitted adverse comments regarding the State's and the EPA's
evaluation of interstate transport for the 2008 ozone NAAQS.\18\ The
two remaining letters were anonymous comment letters that raised issues
outside the scope of this rulemaking and did not identify any material
issues necessitating a
[[Page 65098]]
response.\19\ The comment letters are available in the docket for this
rulemaking.
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\17\ Letter dated March 9, 2018, from Kurt Karperos, Deputy
Executive Officer, CARB to Alexis Strauss, Acting Regional
Administrator, EPA Region IX.
\18\ Letter dated March 9, 2018, from Robert Ukeiley, Senior
Attorney, Center for Biological Diversity to Rory Mays, Air Planning
Office, EPA Region IX.
\19\ Comments received on February 21, 2018 and February 27,
2018.
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CBD requests that the EPA disapprove the California Transport Plan
with respect to the 2008 ozone NAAQS. We address CBD's comments in
three parts as follows.
Comment #1: The commenter states that the ozone transport analysis
in the California Transport Plan is flawed because it underestimates
NOX emissions from agricultural soils in California. The
commenter relies on a recent study that concludes that agricultural
soils are a dominant source of California's NOX emissions
(``Soil NOX Study''), especially in the San Joaquin
Valley.\20\ Based on this study, the commenter states that California's
NOX emissions would have been 20 to 51 percent higher and
that, by underestimating such emissions, the California Transport Plan
underestimated California's contribution to downwind states. The
commenter recommends re-running ozone transport modeling with a
corrected NOX emission inventory for California and suggests
that this could change the linkages between California and other states
for ozone. The commenter asserts that, pursuant to the Supreme Court's
holding in Motor Vehicle Manufacturers Association v. State Farm Mutual
Automobile Insurance, it is unlawful to fail to consider an important
aspect of a problem before the agency.\21\
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\20\ Almaraz, et al., ``Agriculture is a major source of
NOX pollution in California,'' Science Advances, January
31, 2018, 1. As this article is copyrighted, it is available in hard
copy, but not available electronically at Regulations.gov, as part
of the docket of this rulemaking; see the ADDRESSES section of this
action for hard copy viewing information. It is also publicly
available at: https://advances.sciencemag.org/content/4/1/eaao3477/tab-pdf.
\21\ 463 U.S. 29, 43 (1983).
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Response #1: The EPA disagrees that the California Transport Plan
is flawed in this manner and that the EPA failed to consider an
important aspect of interstate transport for the 2008 ozone NAAQS. As
an initial matter, the CSAPR Update modeling estimates that California
contributes more than 1 percent of the NAAQS to downwind maintenance
receptors in Denver (i.e., California is ``linked'' to receptors in
Denver). An increase in NOX emissions from California could
potentially increase the magnitude of the contribution to these
receptors but would be unlikely to result in any additional downwind
linkages for California because there are no other nonattainment or
maintenance receptors in the West (excluding California), based on
EPA's CSAPR Update modeling. Moreover, in the CSAPR Update four-step
process, the amount of contribution above the 1 percent threshold is
not a factor in determining whether the upwind state's contribution is
significant or will interfere with maintenance.\22\
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\22\ The 1 percent threshold can serve to limit the scope of an
upwind state's emission reduction obligation if upwind emission
reductions would otherwise reduce a state's impact to below the
threshold. See EME Homer City Generation, L.P. v. EPA, 134 S. Ct.
1584, 1608-09 (2014) (the EPA cannot require a state to reduce its
contribution to every receptor to which it is linked to below 1
percent of the NAAQS). In this action, however, the EPA has not
concluded that California's impact to any downwind receptors would
be reduced below the 1 percent threshold as a result of the emission
controls implemented by the State's SIP. Therefore, the potential
additional impact of NOX emissions resulting from
agricultural soils would not implicate this limit on the Agency's
statutory authority.
---------------------------------------------------------------------------
Although the study upon which the commenter relies was not
published until after the EPA's proposed rulemaking was signed on
January 26, 2018, we have considered the commenter's statement and the
study on possible underestimation of NOX emissions from
agricultural soils in California and potential effects in analyzing
California's contribution to ozone in downwind states. Accordingly, we
present a brief synopsis of how the CSAPR Update modeling accounted for
NOX emissions from land in California, as well as a summary
of the Soil NOX Study referenced by the commenter and our
evaluation thereof with respect to this rulemaking.
In 2016, the EPA's CSAPR Update modeling used NOX
emissions from soils for the continental U.S based on application of
the Biogenic Emissions Inventory System (BEIS version 3.61).\23\
Emissions of soil NOX vary by land cover type and,
accordingly, model emission factors vary for each type of land cover.
For example, the emission factor for agricultural lands is relatively
higher than grasslands due to application of nitrogen-based
fertilizers. The annual soil NOX emissions from California
were estimated to be 30,593 tpy in both 2011 and 2017, which
corresponds to 4.1 percent of the total 2011 NOX inventory
for California (740,179 tpy) and 5.6 percent of the total 2017 base
case NOX inventory (544,972 tpy), respectively. Thus, the
CSAPR Update modeling accounted for the effect of California's soil
NOX emissions on ozone formation and downwind transport to
other states.
---------------------------------------------------------------------------
\23\ Information on BEIS can be found at https://www.epa.gov/air-emissions-modeling/biogenic-emission-inventory-system-beis. This
web page includes a brief version history of BEIS, including points
at which the system's soil NO algorithm was revised based on the
work of peer-reviewed research papers, and a list of BEIS references
at https://www.epa.gov/sites/production/files/2015-10/documents/beis_references.pdf. The EPA's emissions modeling platform TSD for
the CSAPR Update final rule describes how BEIS was used to estimate
emissions from soils and vegetation. ``Technical Support Document
(TSD) Preparation of Emission Inventories for the Version 6.3, 2011
Emissions Modeling Platform,'' EPA, August 2016, 33-35.
---------------------------------------------------------------------------
In the Soil NOX Study, the authors generated annual
estimates of soil NOX emissions from California using a
nitrogen isotope model and the Integrated Model for the Assessment of
the Global Environment at a 4 kilometer (km) by 4 km resolution. These
complex biogeochemical models include the full suite of variables
thought to contribute to soil NOX emissions. The model
results were compared to a limited number of observations from surface
measurements around California. The average modeled NOX
emissions were comparable to the surface measurements in some areas and
larger than the surface measurements in other areas.\24\
---------------------------------------------------------------------------
\24\ Soil NOX Study, Table 1, 3.
---------------------------------------------------------------------------
The authors then compared model predicted emissions to CARB's non-
soil NOX emissions inventory and estimated that soil
NOX emissions account for 25 percent of California's total
NOX emissions.\25\ They note that this is in the range of
previous modeling studies that considered agricultural soils worldwide.
With respect to the San Joaquin Valley, the study also used airborne
and surface measurements of NOX from a separate study \26\
to estimate total NOX emissions from a portion of the San
Joaquin Valley of 190 metric tons of nitrogen per day (tnpd), with a
range of plus or minus 130 tnpd.
---------------------------------------------------------------------------
\25\ The Soil NOX Study notes that CARB ascribes
about 3.8 percent of California's total NOX emissions to
cropland soils. Soil NOX Study, p. 1. The commenters did
not attempt to further compare the model results of the Soil
NOX Study with the emissions inventory used in the
California Transport Plan (based on the initial CSAPR Update
modeling) nor the CSAPR Update modeling, upon which the EPA's
proposed rulemaking was based. Notwithstanding, the proportion of
CARB's cropland NOX emissions estimates appear to fall in
a similar scale to those modeled for the EPA's CSAPR Update rule.
\26\ Trousdell, et al., ``Observing entrainment mixing,
photochemical ozone production, and regional methane emissions by
aircraft using a simple mixed-layer framework,'' Atmospheric
Chemistry and Physics. 16, 15433-15450 (2016).
---------------------------------------------------------------------------
The Soil NOX Study concludes that it is the first study
to include a spatially explicit estimate of soil NOX
emissions compared to other emission sources in California. While
acknowledging the uncertainty in the estimate, the Soil NOX
Study further concludes that its model results add to a growing body of
[[Page 65099]]
literature suggesting that soil NOX emissions could be
significantly underestimated in current inventories and possibly
increase California's total NOX emissions by 20 to 51
percent.\27\
---------------------------------------------------------------------------
\27\ Id. at 1.
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The EPA acknowledges the value that studies of this kind contribute
towards a better understanding of soil NOX emissions from
California. However, the quantification of such emissions is currently
uncertain, as described below, and would require further field research
to substantiate. The commenters did not address the uncertainties
expressed in the study and did not consider other important analytical
aspects of interstate transport of ozone.
First, the study acknowledges that a limited number of surface
measurements were available for purposes of comparing the model results
and, where observations exist, there is a large range in observed
values due to varying soil conditions (e.g., relating to temperature,
moisture, fertilizer application, etc.). The authors acknowledge the
difficulty in comparing the model results to the observations and note
the need for more field measurements.\28\ Second, there was a
significant degree of uncertainty in the aircraft estimates of
NOX emissions over the San Joaquin Valley (190 tnpd plus or
minus 130 tnpd, which equates to plus or minus 68 percent). Further
research would be needed to determine whether these higher levels of
soil NOX emissions over California and elsewhere are
accurate and reliable before updates are included in air quality
modeling to support regulatory decisions.\29\
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\28\ Id. at 5.
\29\ Technical comments have been published in response to the
Soil NOX Study that present additional uncertainties
(with respect to the calculations used) in the Soil NOX
Study and recommend supplemental data that could be released to
allow for an improved assessment of the study. Maaz, et al.,
``Inconsistencies undermine the conclusion that agriculture is a
dominant source of NOX in California,'' Science Advances,
September 12, 2018. As these technical comments are copyrighted,
they are available in hard copy as part of the docket of this
rulemaking; see the ADDRESSES section of this action for viewing
information. They are also publicly available at: https://advances.sciencemag.org/content/4/9/eaat4706?intcmp=trendmd-adv.
---------------------------------------------------------------------------
Furthermore, in the EPA's proposed rulemaking, we described the
rationale for our disagreement with CARB's assertions in the California
Transport Plan that California's contributions to ozone levels in the
Denver area were overestimated, while acknowledging that the future
research that CARB suggests to better characterize ozone transport from
California to other states could prove valuable.\30\ In this response,
we disagree with the commenter that California's contributions to such
ozone levels were underestimated, while similarly acknowledging the
value of further research to better characterize California's
NOX emissions. In both cases, however, we assert that the
prospect of future research that might better quantify California's
emissions or their effect on other states' ozone levels does not itself
undermine the technical adequacy of the EPA's current modeling for the
2008 ozone NAAQS. We reaffirm that the CSAPR Update modeling, including
its emissions inventory bases, and our analysis with respect to
California based on that modeling adequately estimate the interstate
transport of ozone from California to downwind states.
---------------------------------------------------------------------------
\30\ 83 FR 5375, 5380 (February 7, 2018).
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In sum, the soil NOX emissions used in the CSAPR Update
modeling, upon which our evaluation of the California Transport Plan
relies for the 2008 ozone NAAQS, were based on the BEIS, which
incorporates prior research on soil NOX as noted above.
While the Soil NOX Study suggests that California's soil
NOX emissions may be underestimated, they have not been
adequately quantified and verified to a sufficient degree to replace
the emissions inventories that were part of the analytical basis of the
EPA's proposal to approve California Transport Plan for the 2008 ozone
NAAQS, nor to warrant re-running the ozone transport modeling.
Furthermore, the CSAPR modeling and our proposed finding did indicate
that California is linked to downwind receptors, and therefore we
presented a general assessment of cost-effective controls that can be
employed to reduce emissions from sources in California.
The EPA therefore disagrees that it has failed to consider an
important aspect of the interstate transport problem in violation of
the Supreme Court's holding in State Farm. We affirm that the EPA has
considered the multiple important aspects of interstate transport of
ozone from California to other states, as described in our proposed
rulemaking and in this final rule's response to comments. These aspects
include, but are not limited to, consideration of measured and modeled
ambient ozone concentrations, measured and estimated NOX and
VOC emissions inventories for California and the continental U.S.,
application of state of the science modeling tools for regional air
pollution analysis and appropriate model validation, existing and
planned emission control regimes, and meteorology. Furthermore, we have
considered the commenter's arguments with respect to California's soil
NOX emissions and disagree that the science of such
emissions is quantified and verified to a sufficient degree to warrant
a new analysis of interstate transport from California to other states
for the 2008 ozone NAAQS.
Comment #2: The commenter states that the ozone transport analysis
in the California Transport Plan is flawed by failing to consider
whether soil NOX emissions from California are adequately
controlled. Specifically, the commenter states that the EPA failed to
consider whether California has rules to limit NOX via
agricultural management practices, whether such rules are in the
California SIP, and whether such rules are adequate. The commenter does
not believe that such rules are in place.
Response #2: We disagree with the commenter's assertion that the
California Transport Plan should have examined whether soil
NOX emissions are subject to control and whether such
controls are adequate for purposes of the interstate transport
requirements for the 2008 ozone NAAQS. This flows from our
considerations expressed in Response #1 of this final rule. We do not
consider the Soil NOX Study alone to be sufficient to compel
replacement of the emissions inventories that were the analytical bases
of the EPA's proposal, particularly given the study's wide range of
suggested soil NOX emission increases (20 to 51 percent for
California) and the large uncertainty in the model results.
Soil NOX emissions occur across California's wide range
of ecological regions \31\ and NOX emissions from
agricultural regions in the State represent a subset of the statewide
annual soil NOX estimate. Within the agricultural regions,
the amount of soil NOX emitted varies based on agricultural
practices employed (e.g., irrigation; method, timing, and amount of
fertilizer application; etc.), crop type, temperature, and other
factors. Additionally, soil NOX is not directly emitted
(e.g., nitrifying bacteria in the soil convert ammonium from various
sources into NOX, some of which is emitted into the
atmosphere) and involves numerous natural emissions sources and
processes. Therefore, the production of NOX in the soil is
quite complex and inherently difficult to estimate and model.
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\31\ A map of California's ecological regions is available at:
https://www.epa.gov/eco-research/ecoregion-download-files-state-region-9.
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In addition, the commenter did not provide examples or
recommendations of alternative agricultural practices that might reduce
soil NOX emissions in California. Even if there were known
[[Page 65100]]
alternative practices, it may prove difficult to estimate the effect of
those potential controls given the complexity of soil NOX
production. Given the complexity in estimating and modeling soil
NOX emissions, the indirect and partially natural source of
the emissions, the absence of specific alternative measures that could
be implemented to reduce soil NOX emissions, and the
uncertainty in the effectiveness of potential emission controls, the
EPA concludes that there is not sufficient information available at
this time to warrant an evaluation of potential control of soil
NOX emissions in California for purposes of interstate
transport prongs 1 and 2 for the 2008 ozone NAAQS.
Therefore, we reaffirm that our approach of evaluating California's
largest sources of NOX emissions and the control measures
for such sources, including mobile sources (70 percent of the projected
2017 emissions inventory) and stationary point sources (15 percent of
the inventory, including EGUs and non-EGU sources), is a reasonable
means for assessing whether California has satisfied the interstate
transport requirements of CAA section 110(a)(2)(D)(i)(I) with respect
to the 2008 ozone NAAQS.
Comment #3: Lastly, the commenter asserts that measures to control
NOX emissions from cropland soils will bring economic,
ecosystem, and human health co-benefits to rural California, per the
recent study. On this basis, the commenter disagrees that the EPA lacks
discretionary authority under Executive Order 12898 to address
disproportionate human health or environmental effects and highlights
the San Joaquin Valley as an area with many communities that suffer
environmental injustice. The commenter states that the California
Transport Plan should include measures to control NOX
emissions from agricultural soils to reduce pollution in such
communities, consistent with Executive Order 12898.
Response #3: We disagree that the EPA has discretionary authority
in this rulemaking under Executive Order 12898 to address any
disproportionate human health or environmental effects in rural
California. First, Executive Order 12898 applies only to federal agency
actions that invoke certain federal requirements, such as the National
Environmental Policy Act or CAA section 309, and it does not apply
where the EPA is merely approving a state submission as meeting basic
requirements of the CAA. Second, this rulemaking concerns the
interstate transport of ozone from California to other states under CAA
section 110(a)(2)(D)(i)(I), rather than the effect of California's
NOX emissions on communities within California. Thus, the
commenters suggestion that California should control NOX
emissions from cropland soils to reduce pollution that may affect
communities in California is outside the scope of this rulemaking. For
these reasons, Executive Order 12898 is not applicable to this action.
III. EPA Action
We have reviewed the California Transport Plan for the 2008 ozone,
2006 PM2.5, 2012 PM2.5, and 2010 SO2
NAAQS using step-wise processes. Based on this review and additional
analyses conducted by the EPA to verify and supplement the California
Transport Plan, and consistent with CAA section 110(a)(2)(D)(i)(I) and
EPA guidance with respect to interstate transport for these NAAQS, we
find that California will not significantly contribute to
nonattainment, or interfere with maintenance, of the 2008 ozone, 2006
PM2.5, 2012 PM2.5, and 2010 SO2 NAAQS
in any other state. No comments were submitted that change our
assessment of the California Transport Plan as described in our
proposed rulemaking. Therefore, as authorized in section 110(k)(3) of
the Act, the EPA is fully approving the California Transport Plan into
the California SIP for the requirements of CAA section
110(a)(2)(D)(i)(I) for these NAAQS.
In addition, for the 2006 PM2.5 and 2008 ozone NAAQS,
the EPA had previously found that California failed to submit the
required SIP revisions addressing interstate transport prongs 1 and 2
by certain dates.\32\ Those actions triggered the obligation for the
EPA to promulgate a federal implementation plan (FIP) for these
requirements unless the State submitted and the EPA approved a SIP
submission that addresses the two prongs. As the EPA is fully approving
the California Transport Plan for these two NAAQS, this final rule also
removes the obligation for the EPA to promulgate such FIPs.
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\32\ 79 FR 63536 (October 24, 2014) for the 2006
PM2.5 NAAQS; and 80 FR 39961 (July 13, 2015) for the 2008
ozone NAAQS.
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IV. 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, the EPA's role is to approve state
choices, provided that they meet the criteria of the Clean Air Act.
Accordingly, this 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 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 an Executive Order 13771 (82 FR 9339, February 2,
2017) regulatory action because SIP approvals are exempted 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
Executiv
