[Federal Register Volume 83, Number 67 (Friday, April 6, 2018)]
[Proposed Rules]
[Pages 14807-14826]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-06847]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R08-OAR-2017-0567, FRL-9975-09--Region 8]
Promulgation of State Implementation Plan Revisions; Colorado;
Attainment Demonstration for the 2008 8-Hour Ozone Standard for the
Denver Metro/North Front Range Nonattainment Area, and Approval of
Related Revisions
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: On May 31, 2017, the State of Colorado submitted State
Implementation Plan (SIP) revisions related to attainment of the 2008
8-hour ozone National Ambient Air Quality Standards (NAAQS) for the
Denver Metro/North Front Range (DMNFR) Moderate nonattainment area by
the applicable attainment date of July 20, 2018. The Environmental
Protection Agency (EPA) proposes to approve the majority of the
submittal, which includes an attainment demonstration, base and future
year emission inventories, a reasonable further progress (RFP)
demonstration, a reasonably available control measures (RACM) analysis,
a motor vehicle inspection and maintenance (I/M) program in Colorado
Regulation Number 11 (Reg. No. 11), a nonattainment new source review
(NNSR) program, a contingency measures plan, 2017 motor vehicle
emissions budgets (MVEBs) for transportation conformity, and revisions
to Colorado Regulation Number 7 (Reg. No. 7). The EPA is also proposing
to approve portions of the reasonably available control technology
(RACT) analysis. Finally, the EPA proposes to approve revisions made to
Colorado's Reg. No. 7 in a May 5, 2013 SIP submission. This action is
being taken in accordance with the Clean Air Act (CAA).
DATES: Comments must be received on or before May 7, 2018.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R08-
OAR-2017-0567, at http://www.regulations.gov. Follow the online
instructions for submitting comments. Once submitted, comments cannot
be edited or removed from Regulations.gov. The EPA may publish any
comment received to its public docket. Do not submit electronically any
information you consider to be Confidential Business Information (CBI)
or other information whose disclosure is restricted by statute.
Multimedia submissions (audio, video, etc.) must be accompanied by a
written comment. The written comment is considered the official comment
and should include discussion of all points you wish to make. The EPA
will generally not consider comments or comment contents located
outside of the primary submission (i.e., on the web, cloud, or other
file sharing system). For additional submission methods, the full EPA
public comment policy, information about CBI or multimedia submissions,
and general guidance on making effective comments, please visit http://www2.epa.gov/dockets/commenting-epa-dockets.
FOR FURTHER INFORMATION CONTACT: Abby Fulton, Air Program, U.S.
Environmental Protection Agency (EPA), Region 8, Mail Code 8P-AR, 1595
Wynkoop Street, Denver, Colorado 80202-1129, (303) 312-6563,
[email protected].
SUPPLEMENTARY INFORMATION:
I. What action is the Agency taking?
As explained below, the EPA is proposing various actions on
Colorado's proposed revisions to its SIP that it submitted to the EPA
on May 5, 2013, and May 31, 2017. Specifically, we are proposing to
approve Colorado's 2017 attainment demonstration for the 2008 8-hour
ozone NAAQS. In addition, we propose to approve the MVEBs contained in
the State's submittal. We also propose to approve all other aspects of
the submittal, except for certain area source categories and major
source RACT, which we will be acting on at a later date. We propose to
approve the revisions to Colorado's Reg. 11 and 7, except for Section
X.E of Reg. 7, which we will be acting on at a later date. We propose
to approve the revisions to Colorado Reg. 7 Sections I, II, VI, VII,
VIII, and IX from the State's May 5, 2013 submittal.
The specific bases for our proposed actions and our analyses and
findings are discussed in this proposed rulemaking. Technical
information that we rely upon in this proposal is contained in the
docket, available at http://www.regulations.gov, Docket No. EPA-R08-
OAR-2017-0567.
II. Background
On March 12, 2008, the EPA revised both the primary and secondary
NAAQS for ozone to a level of 0.075 parts per million (ppm) (based on
the annual fourth-highest daily maximum 8-hour average concentration,
averaged over 3 years) to provide increased protection of public health
and the environment (73 FR 16436, March 27, 2008). The 2008 ozone NAAQS
retains the same general form and averaging time as the 0.08 ppm NAAQS
set in 1997, but is set at a more protective level. Specifically, the
2008 8-hour ozone NAAQS is attained when the 3-year average of the
annual fourth-highest daily maximum 8-hour average ambient air quality
ozone concentrations is less than or equal to 0.075 ppm. See 40 CFR
50.15.
Effective July 20, 2012, the EPA designated as nonattainment any
area that was violating the 2008 8-hour ozone NAAQS based on the three
most
[[Page 14808]]
recent years (2008-2010) of air monitoring data (77 FR 30088, May 21,
2012). With that rulemaking, the DMNFR area was designated
nonattainment and classified as Marginal. Ozone nonattainment areas are
classified based on the severity of their ozone levels. This is
determined using the area's design value. The design value is the 3-
year average of the annual fourth highest daily maximum 8-hour average
ozone concentration at a monitoring site. See 40 CFR part 50, Appendix
I. The DMNFR nonattainment area includes Adams, Arapahoe, Boulder,
Broomfield, Denver, Douglas and Jefferson Counties, and portions of
Larimer and Weld Counties. See 40 CFR 81.306. Areas that were
designated as Marginal nonattainment were required to attain the 2008
8-hour ozone NAAQS no later than July 20, 2015, based on 2012-2014
monitoring data.
On May 4, 2016, the EPA published its determination that the DMNFR,
among other areas, had failed to attain the 2008 8-hour ozone NAAQS by
the attainment deadline, and that the DMNFR was accordingly
reclassified to a Moderate ozone nonattainment area (81 FR 26697; see
40 CFR 81.306). Moderate areas are required to attain the 2008 8-hour
ozone NAAQS by no later than 6 years after the effective date of
designation, which for the DMNFR nonattainment area is July 20, 2018.
See 40 CFR 51.903.
III. Analysis of the State's Submission
CAA Section 182, 42 U.S.C. 7511a, outlines SIP requirements
applicable to ozone nonattainment areas in each classification
category. Moderate area classification triggers additional state
requirements established under the provisions of the EPA's ozone
implementation rule for the 2008 8-hour ozone NAAQS. See 40 CFR part
51, subpart AA. Examples of these requirements include submission of a
modeling and attainment demonstration, RFP, RACT, and RACM. Moderate
nonattainment areas had a submission deadline of January 1, 2017 for
these SIP revisions (81 FR 26697, 26699, May 4, 2016).
Colorado submitted revisions to its SIP to the EPA on May 31, 2017,
to meet the requirements of a Moderate area classification for the
DMNFR nonattainment area and attain the 2008 8-hour ozone NAAQS.
Colorado's proposed SIP revisions consist of the parts listed below.
8-Hour Ozone Attainment Plan (OAP), which includes
monitoring information, emission inventories, an RFP demonstration, an
attainment demonstration using photochemical grid modeling, a weight of
evidence analysis, a RACT analysis, a RACM analysis, a motor vehicle
emissions I/M program, NNSR program certification, contingency
measures, and 2017 MVEBs for transportation conformity.
Revisions to Reg. No. 7.
Revisions to Reg. No. 11.
The Reg. No. 7 revisions in the 2017 submission include rule
revisions related to the Moderate ozone nonattainment classification
and revisions that address the EPA's concerns with previous SIP
submittals. In this action, we are also acting on Reg. No. 7 revisions
from a May 5, 2013 SIP submission. Reg. No. 11 revisions remove
``state-only'' references in Part A, regarding Larimer and Weld
counties, thereby making the entire motor vehicle inspection and
maintenance program federally enforceable.
The provisions we propose to approve meet the requirements of the
CAA and our regulations. The specific bases for our proposed actions
and our analyses and findings are discussed in this proposed
rulemaking. Technical information that we rely on in this proposal is
contained in the docket, available at http://www.regulations.gov,
Docket No. EPA-R08-OAR-2017-0567.
A. Procedural Requirements
The CAA requires that states meet certain procedural requirements
before submitting SIP revisions to the EPA. Specifically, section
110(a)(2) of the CAA, 42 U.S.C. 7410(a)(2), requires that states adopt
SIP revisions after reasonable notice and public hearing. For the May
5, 2013 submittal, the Colorado Air Quality Control Commission (AQCC)
provided notice in the Colorado Register on September 21, 2012, and
held a public hearing on December 20, 2012. The Colorado AQCC adopted
the SIP revisions on December 20, 2012. The SIP revisions became state-
effective on February 15, 2013. For the May 31, 2017 submission, the
Colorado AQCC provided notice in the Colorado Register on July 29 and
August 29, 2016 and held a public hearing on the SIP revisions on
November 17, 2016. The Colorado AQCC adopted the SIP revisions on
November 17, 2016. The SIP revisions became state-effective on January
14, 2017. Colorado met the CAA's procedural requirements for reasonable
notice and public hearing.
IV. EPA's Evaluation of Colorado's Submission
A. Monitoring
Ozone monitoring data are used as a basis for photochemical grid
modeling in the attainment demonstration. The EPA requirements for
ambient monitoring are in 40 CFR part 58. Colorado collected ozone
monitoring data in accordance with these requirements and with the
EPA's ``Quality Assurance Handbook for Air Pollution Measurement
Systems, Vol. II--Ambient Air Quality Monitoring Program''; \1\ the
Colorado Air Pollution Control Division's (APCD) Quality Management
Plan \2\ and Quality Assurance Project Plan; \3\ and Colorado's
monitoring network plan.\4\
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\1\ QA Handbook for Air Pollution Measurement Systems: ``Volume
II: Ambient Air Quality Monitoring Program'' (EPA-454/B-13-003, May
2013) (available in the docket). The current version of the Handbook
is available at https://www3.epa.gov/ttn/amtic/files/ambient/pm25/qa/FinalHandbookDocument1_17.pdf (EPA-454/B-17-001, Jan. 2017).
\2\ Colorado Department of Public Health and Environment,
Quality Management Plan (March 2016), available in the docket.
\3\ Colorado Department of Public Health and Environment,
Quality Assurance Project Plan (July 2015), available in the docket.
\4\ Annual Network Plans available at https://www.colorado.gov/airquality/tech_doc_repository.aspx.
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The monitoring section of Colorado's OAP includes:
Information on the location of ozone monitors in Colorado,
from southern Metropolitan Denver to northern Fort Collins (including
Rocky Mountain National Park);
4th-maximum monitored 8-hour ozone values from 2006
through 2015, including levels recorded above the 75 parts per billion
(ppb) 2008 ozone NAAQS; \5\
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\5\ OAP Table 3.
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A description of the State's ambient air quality data
assurance program; and
Relevant 8-hour-average ozone monitoring data and recovery
rates from 2006 through September 2015.
B. Emissions Inventories
1. Background
CAA section 172(c)(3), 42 U.S.C. 7502(c)(3), requires that each SIP
include a ``comprehensive, accurate, current inventory of actual
emissions from all sources of the relevant pollutant or pollutants in
[the] area.'' The accounting required by this section provides a ``base
year'' inventory that serves as the starting point for attainment
demonstration air quality modeling, for assessing RFP, and for
determining the need for additional SIP control measures. An attainment
year inventory is a projection of future emissions and is necessary to
show the effectiveness of SIP control measures. Both the base year and
attainment year inventories are necessary for
[[Page 14809]]
photochemical modeling to demonstrate attainment. Section D includes
additional discussion on how these inventories are used in the
attainment modeling.
Colorado's DMNFR area attainment plan includes a 2011 base year
inventory and a 2017 attainment year inventory. The inventories catalog
NOX and VOC emissions, because these pollutants are
precursors to ozone formation, across all source categories during a
typical summer day, when ozone formation is pronounced. Carbon monoxide
(CO) emissions are reported as well, because they also impact ozone
chemistry.
In our 2008 ozone NAAQS implementation rule, the EPA recommends
using 2011 as the baseline year (80 FR 12264, 12272). In addition,
analysis of meteorological conditions in the DMNFR area leads to the
conclusion that the summer of 2011 was a ``typical'' ozone season from
a meteorological standpoint. The modeling analysis uses a base year of
2011 to develop the modeling inputs for the base year modeling analysis
and model performance evaluation.
2. Evaluation
The 2011 base year emissions inventory and the 2017 attainment year
emissions inventory were developed using EPA-approved guidelines for
stationary, mobile, and area emission sources. Stationary source
emissions data for 2011 were self-reported to the State by individual
sources; the State then used the submitted 2011 information to project
stationary source emissions for 2017. On-road and non-road mobile
source emissions were calculated using the EPA's MOVES2014 model
combined with local activity inputs including vehicle miles traveled
(VMT) and average speed data, as well as local fleet, age distribution,
meteorology, and fuels information. Area sources include many
categories of emissions. The EPA finds that these sources (including
those in the oil and gas sector) were adequately accounted for in the
emissions inventory. The methodology used to calculate emissions for
each respective category followed relevant EPA guidance; \6\ \7\ as
applicable, employed approved emission factors and National Emissions
Inventory (NEI) data; and was sufficiently documented in the SIP and in
the State's technical support documents (TSD).\8\
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\6\ Emissions Inventory Guidance for Implementation of Ozone and
Particulate Matter National Ambient Air Quality Standards (NAAQS)
and Regional Haze Regulations, EPA-454/B-17-003, available at
https://www.epa.gov/sites/production/files/2017-07/documents/ei_guidance_may_2017_final_rev.pdf (hereinafter referred to as
``Emissions Inventory Guidance'') (July 2017).
\7\ MOVES2014 and MOVES2014a Technical Guidance: Using MOVES to
Prepare Emission Inventories for State Implementation Plans and
Transportation Conformity, EPA-420-B-15-093, available at https://nepis.epa.gov/Exe/ZyPDF.cgi/P100NN9L.PDF?Dockey=P100NN9L.PDF
(hereinafter referred to as ``MOVES Guidance'') (Nov. 2015).
\8\ See Colorado OAP, TSD Part 1, 2011-2017 Mobile and Area
Sources Emissions Inventory Development, p. 1202.
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Projected future emissions in 2017 were based on anticipated
growth, technological advancements, and expected emissions controls
that were to be implemented by the 2017 ozone season. Table 1 shows the
emissions by source category from the 2011 base year and 2017
attainment year emission inventories.
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\9\ Emissions in Table 1 are reflective of an average summer
day.
Table 1--Emissions Inventory Data for Specific Source
[Tons/avg. episode day] \9\
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2011 2017
Description -----------------------------------------------------------------
VOC NOX CO VOC NOX CO
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Oil and Gas Sources:
Point Sources Subtotal.................... 14.8 18.1 17.0 16.3 20.6 19.7
Condensate Tanks Subtotal................. 216 1.1 2.3 78.7 0.6 2.3
Area Sources Subtotal..................... 48.9 22.2 12.9 59.0 44.6 31.4
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Total................................. 279.7 41.4 32.2 154 65.8 53.4
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Point Sources (EGU and Non-Oil and Gas):
Electric Generating Units (EGUs).......... 0.7 39.7 3.6 0.4 19.2 2.9
Point (Non-Oil and Gas)................... 25.9 21.0 14.1 28.0 20.9 14.4
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Total................................. 26.6 60.7 17.7 28.4 40.1 17.3
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Area Sources (Non-Oil and Gas):
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Total................................. 60.6 0.0 1.4 67.5 ......... 1.6
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Non-Road Mobile Sources:
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Total................................. 58.2 75.9 800.2 44.3 54.9 759.7
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On-Road Mobile Sources:
Light-Duty Vehicles....................... 90.0 102.5 812.2 52.4 50.3 538.6
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Medium/Heavy-Duty Vehicles................ 3.7 39.6 20.6 2.6 23.0 16.2
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Total................................. 93.7 142.1 832.8 55.0 73.3 554.8
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Total Anthropogenic Emissions..... 518.8 320.1 1,684.3 349.2 234.1 1,386.8
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Total Biogenic Sources............ 170.5 6.1 21.6 170.5 6.1 21.6
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[[Page 14810]]
Total Nonattainment Area Emissions 689.3 326.2 1,705.9 519.7 240.2 1,408.4
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Details of Colorado's emissions inventory development are in
Colorado's supporting TSD.\10\ The inventories in the SIP are based on
the most current and accurate information available to the State and
the Regional Air Quality Council (RAQC) at the time the SIP was being
developed. Additionally, the inventories comprehensively address all
source categories in the DMNFR nonattainment area, and were developed
consistent with the relevant EPA inventory guidance. For these reasons,
we propose to approve the 2011 baseline emissions inventory as meeting
the requirements of CAA section 172(c)(3), 42 U.S.C. 7502(c)(3). The
EPA also finds that the 2017 inventory, which will be used to meet RFP
and attainment demonstration requirements, was developed consistent
with relevant EPA Emissions Inventory Guidance and MOVES Guidance.
Further discussion on RFP and attainment demonstration is provided in
their respective sections.
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\10\ See Colorado OAP, TSD Part 1, 2011-2017 Mobile and Area
Sources Emissions Inventory Development, p. 1202.
\10\ Emissions in Table 1 are reflective of an average summer
day.
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C. Reasonable Further Progress Demonstration
1. Background
Section 182(b)(1) of the CAA, 42 U.S.C. 7511a(b)(1), and the EPA's
2008 Ozone Implementation Rule require each 8-hour ozone nonattainment
area designated Moderate and above to submit an RFP demonstration for
review and approval into its SIP that describes how the area will
achieve actual VOC and NOX emissions reductions from a
baseline emissions inventory. Section 182(b)(1), 42 U.S.C. 7511a(b)(1),
which is part of the ozone-specific requirements of Subpart 2 of the
CAA's nonattainment plan requirements, requires RFP to demonstrate a
15% reduction in VOC emissions. This requirement applies before the
more general Subpart 1 RFP requirements of CAA Section 172(c)(2), 42
U.S.C. 7502(c)(2), which permits a combination of VOC and
NOX emission reductions to show RFP. Colorado has not
previously submitted a 15% RFP SIP under Section 182(b)(1). Therefore,
on May 31, 2017, the State submitted an RFP demonstration showing VOC
emission reductions greater than 15% within six years after the 2011
base year inventory (between 2012-2017).
RFP plans must also include an MVEB, which provides the allowable
on-road mobile emissions an area can produce while still demonstrating
RFP. The State's RFP submittal included MVEBs for the DMNFR area for
the year 2017 (see Chapter 11 of the State's OAP). The MVEBs are
discussed in detail in Section M of this notice.
2. Evaluation
To demonstrate compliance with RFP requirements, the State compared
its 2011 base year VOC emissions inventory against its projected 2017
VOC emissions inventory and demonstrated that the projected milestone
year inventory (2017) emissions of VOC will be at least 15% below the
2011 base year inventory. Colorado projects a 32.7% reduction in VOC
emissions from 2011-2017 (see OAP, Table 25 on page 4-21). As discussed
above in section IV.B., the EPA reviewed the procedures Colorado used
to develop its projected inventories and found them to be reasonable.
D. Photochemical Grid Modeling
1. Background
Under the 2008 Ozone Implementation Rule, Moderate ozone
nonattainment areas are required to demonstrate attainment using
``photochemical modeling or another equivalent analytical method that
is determined to be at least as effective. . . .'' 80 FR at 12268. The
EPA explained that ``photochemical modeling is the most scientifically
rigorous technique to determine NOX and/or VOC emissions
reductions needed to show attainment of the NAAQS.'' Id. at 12269.
Consistent with the 2015 Ozone Implementation Rule, the SIP includes
photochemical grid modeling with supplemental analyses to demonstrate
that the emissions control strategy leads to attainment of the NAAQS by
2017. The modeling effort was led by the RAQC in coordination with the
Colorado Department of Public Health and Environment (CDPHE). The RAQC
first developed a modeling protocol \11\ that describes the model
configuration, domain, input data, and analyses to be performed for the
SIP. As described in the protocol, the RAQC selected summer 2011 for
the attainment demonstration base case model simulation using the 2011
base year emissions inventory. The modeling platform used the Weather
Research and Forecasting Model (WRF) \12\ to simulate meteorological
data fields, and the Comprehensive Air Quality Model with Extensions
(CAMx) as the photochemical air quality model. The modeling platform
used a high resolution 4-km grid for the State of Colorado, nested
within a western U.S. 12-km grid and a 36-km North America CAMx
simulation developed by the Western Air Quality Study.\13\ Day-specific
boundary conditions for the 36-km CAMx simulation were derived from a
2011 simulation of the MOZART model.\14\ The Sparse Matrix Operating
Kernel Emissions (SMOKE) model \15\ was used to process emissions data,
and the Model of Emissions of Gases and Aerosols from Nature (MEGAN)
\16\ was
[[Page 14811]]
used to estimate biogenic emissions of VOC and NOX. The
anthropogenic precursor emissions data were based on the 2011 NEI \17\
with updates in key source categories, including oil and gas
emissions,\18\ mobile and area source emissions,\19\ and point source
emissions.\20\ The EPA reviewed each of the modeling documents listed
above and determined that the modeling is consistent with the
recommendations in the relevant EPA guidance.\21\
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\11\ ENVIRON International Corporation, User's Guide
Comprehensive Air-quality Model with Extensions Version 6.2,
available at http://www.camx.com/files/camxusersguide_v6-20.pdf
(March 2015).
\12\ Weather Research and Forecasting model web page available
at https://www.mmm.ucar.edu/weather-research-and-forecasting-model.
\13\ Adelman, Z., Shanker, U., Yang, and Morris, R., CAMx
Photochemical Grid Model Draft Model Performance Evaluation
Simulation Year 2011, available at http://vibe.cira.colostate.edu/wiki/Attachments/Modeling/3SAQS_Base11a_MPE_Final_18Jun2015.pdf
(June 2015); Ramboll Environ, Attainment Demonstration Modeling for
the Denver Metro/North Front Range 2017 8-Hour Ozone State
Implementation Plan, Draft Modeling Protocol, Prepared for Regional
Air Quality Council, available at https://raqc.egnyte.com/dl/gFls58KHSM/Model_Protocol_Denver_RAQC_2017SIPv4.pdf (Aug. 2015).
\14\ Emmons, L. K., et al., Description and Evaluation of the
Model for Ozone and Related Chemical Tracers, version 4 (MOZART-4),
Geosci. Model Dev., 3, 4367, 2010, 3, pp. 43-67 (Jan. 2010).
\15\ UNC, SMOKE v3.6.5 User's Manual, University of North
Carolina at Chapel Hill, Institute for the Environment, available at
https://www.cmascenter.org/smoke/documentation/3.6.5/html/ (2015).
\16\ Sakulyanontvittaya, T., G. Yarwood and A. Guenther. 2012.
Improved Biogenic Emission Inventories across the West, ENVIRON
International Corporation, available at https://www.wrapair2.org/pdf/WGA_BiogEmisInv_FinalReport_March20_2012.pdf (March 2012).
\17\ 2011 NEI web page available at https://www.epa.gov/air-emissions-inventories/2011-national-emissions-inventory-nei-data.
\18\ See Colorado OAP, TSD Part 1, 2011 and 2017 Oil and Gas
Emissions Inventory Development, p. 1429.
\19\ See Colorado OAP, TSD Part 1, 2011 and 2017 Mobile and Area
Sources Emissions Inventory Development, p. 1202.
\20\ See Colorado OAP, TSD Part 1, 2011 and 2017 Point Source
Emissions Inventory Development, p. 1443.
\21\ Draft Modeling Guidance for Demonstrating Attainment of Air
Quality Goals for Ozone, PM2.5 and Regional Haze, EPA,
available at https://www3.epa.gov/scram001/guidance/guide/Draft_O3-PM-RH_Modeling_Guidance-2014.pdf (Dec. 2014).
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2. Evaluation
EPA guidance recommends that model performance be evaluated by
comparing model-simulated concentrations to observed concentrations.
Model performance evaluation is used to evaluate the model for
historical ozone episodes in the base year and to assess the model's
reliability in projecting future year ozone concentrations. Using
meteorological and emissions data from a historical base period, ozone
and other species concentrations predicted by the model are compared to
monitored concentrations to evaluate model performance. EPA modeling
guidance emphasizes the use of graphical and diagnostic evaluation
techniques to ensure that the modeling captures the correct chemical
regimes and emission sources causing high ozone. Consistent with the
guidance, Colorado's model performance evaluation included a
comprehensive suite of graphical and diagnostic evaluation techniques,
such as time-series plots of modeled and observed ozone at key
monitoring sites, spatial plots of ozone, tabulations of model bias and
error metrics, and diagnostic model simulations using sensitivity and
source apportionment techniques. The WRF and CAMx configuration and MPE
are described in Ramboll Environ's 2011 base case modeling and model
performance evaluation report,\22\ which used both quantitative (model
performance statistics) and qualitative (graphical displays) MPE
approaches. At the four key monitoring sites in the Denver
nonattainment area, the model achieved typical performance goals for
model bias and error. However, as to the Chatfield monitor, which had
the highest ozone design value, the model was biased low for some days
in May and June and biased high for some days in July and August. While
the model achieved the performance goal, it failed to accurately
simulate some of the days with the highest monitored ozone.\23\
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\22\ Ramboll Environ, Denver Metro/North Front Range 2017 8-Hour
Ozone State Implementation Plan: 2011 Base Case Modeling and Model
Performance Evaluation, available at https://raqc.egnyte.com/dl/pxHfZAhquy/TSD_2011_BaseCaseModeling%26MPE.pdf (Sept. 2017).
\23\ As discussed in EPA guidance, it is normal for an air
quality model to have some under-prediction or over-prediction bias
and error in modeled ozone because of uncertainties and errors in
model input data. The relative response factor (RRF) approach that
is recommended in the guidance and that is used in the State's SIP
attainment demonstration is designed to correct for bias in the
model predictions for ozone.
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Because of concerns with model underestimates of ozone on some of
the highest days at the Chatfield monitor and other monitoring sites,
Colorado performed additional weight of evidence (WOE) analysis to
assess model performance and the effect of model performance on the
model attainment demonstration, as discussed in Sections E and F below.
E. Modeled Attainment Demonstration
In the modeled attainment demonstration, emissions inventories are
developed for the attainment year (here, 2017) that reflect emissions
control measures adopted in the SIP as well as other emissions
reductions expected to be achieved through federally enforceable
national programs, such as reduced tailpipe emissions for mobile
sources. The Colorado 2017 emissions inventory is described in the
RAQC's model attainment demonstration report.\24\ The photochemical
model is then used to simulate air quality using the projected 2017
emissions. Because of the concerns with bias and error in the model
performance discussed in the previous section, absolute model results
are not used to evaluate attainment. Instead, the model is used in a
relative sense by calculating the ratio of the model's future (here,
2017) to base case (here, 2011) predictions at ozone monitors in the
nonattainment area. We call these ratios ``Relative Response Factors''
(RRFs). Future ozone concentrations are then estimated at existing
monitoring sites by multiplying the modeled RRF at locations near each
monitor by the observation-based, monitor-specific, baseline design
value. The resulting predicted future concentrations are then compared
with the 2008 8-hour average ozone NAAQS of 75 ppb. If the predicted
future concentrations of ozone are lower than 76 ppb at all monitors,
attainment is demonstrated.\25\ The EPA's ``Model Attainment Test
Software'' (MATS, Abt., 2014 \26\) is used to calculate RRFs and to
perform the attainment demonstration.
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\24\ See Colorado OAP, TSD Part 2, Denver Metro/North Front
Range 2017 8-Hour Ozone State Implementation Plan: 2017 Attainment
Demonstration Modeling, p. 1564.
\25\ In determining compliance with the NAAQS, ozone design
values are truncated to integers. For example, a design value of
75.9 ppb is truncated to 75 ppb. Accordingly, design values at or
above 76.0 ppb are considered nonattainment. See p. 100, footnote 34
of Draft Modeling Guidance for Demonstrating Attainment of Air
Quality Goals for Ozone, PM2.5 and Regional Haze, EPA,
available at https://www3.epa.gov/scram001/guidance/guide/Draft_O3-PM-RH_Modeling_Guidance-2014.pdf (Dec. 2014), and p. 41 of Guidance
on the Use of Models and Other Analyses for Demonstrating Attainment
of Air Quality Goals for Ozone, PM2.5, and Regional Haze,
EPA-454/B-07-002, available at https://www3.epa.gov/ttn/scram/guidance/guide/final-03-pm-rh-guidance.pdf (April 2007).
\26\ Abt Associates Inc., Modeled Attainment Test Software--
User's Manual. available at http://www.epa.gov/ttn/scram/guidance/guide/MATS_2-6-1_manual.pdf (April 2014).
---------------------------------------------------------------------------
Table 2 summarizes Colorado's 2011 base case design values, the
RRFs from the 2017 control measure case modeling, and the projected
2017 future design values. Table 2 shows results for two different
approaches for calculating the model RRF. EPA guidance recommends that
the RRFs be calculated using the maximum modeled ozone in a 3x3 matrix
of grid cells surrounding each monitor. The 3x3 matrix is used because
of the possibility that errors in model inputs or physics can result in
under predictions in the grid cell with the monitor, and because of the
possibility that emissions point sources could be located close to the
edges of grid cells, as discussed in more detail in the modeling
guidance (EPA, 2014, pp. 102-103).
Using the 3x3 RRFs, the maximum projected 8-hour ozone design
values for the 2017 control measure case are 76 ppb at the Chatfield
and the Rocky Flats North monitoring sites. Thus, the primary model
attainment demonstration did not project NAAQS-attaining future design
values (that is, less than 76 ppb) at all monitor sites. When the
primary model attainment demonstration is close to but fails to attain
the NAAQS, EPA guidance recommends that states consider whether it is
appropriate to perform an attainment demonstration using a WOE
demonstration. Colorado performed a
[[Page 14812]]
WOE attainment demonstration as described in Section F below.
Table 2--Current Year Observed 8-Hour Ozone Design Values (DVB), Relative Response Factors (RRF) and Projected 8-Hour Ozone 2017 Future Case Design
Values (DVFs), From Table 3-1 in Ramboll Environ 2016b
--------------------------------------------------------------------------------------------------------------------------------------------------------
3x3 Grid array (4 km) 7x7 Grid array (4 km)
-----------------------------------------------------------------
Base year Future Future
Monitor County (2011) year Final year Final
DVB (ppb) RRF (2017) 2017 DVB RRF (2017) 2017 DVF
DVF (ppb) (ppb) ** DVF (ppb) (ppb) **
** **
--------------------------------------------------------------------------------------------------------------------------------------------------------
Chatfield.................................. Douglas....................... 80.7 0.9453 76.2 76 0.9391 75.7 75
Rocky Flats North.......................... Jefferson..................... 80.3 0.9493 76.2 76 0.9441 75.8 75
NREL....................................... Jefferson..................... 78.7 0.9591 75.4 75 0.9442 74.3 74
Fort Collins West.......................... Larimer....................... 78.0 0.9179 71.5 71 0.9098 70.9 70
Highland................................... Arapahoe...................... 76.7 0.9517 72.9 72 0.9431 72.3 72
Welby...................................... Adams......................... 76.0 0.9512 72.2 72 0.9712 73.8 73
Welch...................................... Jefferson..................... 75.7 0.9538 72.2 72 0.9428 71.3 71
Rocky Mountain NP.......................... Larimer....................... 75.7 0.9464 71.6 71 0.9385 71.0 71
South Boulder Creek........................ Boulder....................... 74.7 0.9477 70.7 70 0.9445 70.5 70
Greeley/Weld Co. Tower..................... Weld.......................... 74.7 0.9422 70.3 70 0.9226 68.9 68
Aspen Park................................. Jefferson..................... 74.5 0.9389 69.9 69 0.9370 69.8 69
Arvada..................................... Jefferson..................... 74.0 0.9723 71.9 71 0.9495 70.2 70
Aurora East................................ Arapahoe...................... 73.5 0.9373 68.8 68 0.9367 68.8 68
Carriage................................... Denver........................ 71.0 0.9695 68.8 68 0.9595 68.1 68
Rist Canyon................................ Larimer....................... 71.0 0.9248 65.6 65 0.9161 65.0 65
Fort Collins CSU........................... Larimer....................... 68.7 0.9217 63.3 63 0.9096 62.4 62
DMAS NCore................................. Denver........................ 65.0 0.9697 63.0 63 0.9522 61.8 61
--------------------------------------------------------------------------------------------------------------------------------------------------------
F. Weight of Evidence Analysis
As noted above, the primary model attainment demonstration
predicted future design values of 76 ppb at two monitors (Rocky Flats
North and Chatfield), and thus these two monitors are not projected to
attain the 75 ppb NAAQS by 2017. EPA guidance recommends a WOE analysis
in cases for which future design values are close to the NAAQS, using
the following criteria for a WOE attainment demonstration:
A fully-evaluated, high-quality modeling analysis that
projects future values that are close to the NAAQS;
A description of each of the individual supplemental
analyses, preferably from multiple categories. Analyses that use well-
established analytical procedures and are grounded with sufficient data
should be weighted higher; and
A written description as to why the full set of evidence
leads to a conclusive determination regarding the future attainment
status of the area that differs from the results of the modeled
attainment test alone.
The WOE analysis can include monitoring and emissions inventory
trend analysis; review of the conceptual model for ozone formation in
the nonattainment area; additional modeling metrics; alternative
attainment test methods; and assessment of the efficacy of SIP-approved
regulations, state-only regulations, and voluntary control measures.
Considering this information and applying the criteria described in the
guidance, the WOE analysis is then used to assess whether the planned
emissions reductions will result in attainment of the NAAQS at the
monitors that modeled ozone future design values of 76 ppb or higher.
As part of its WOE analysis, Colorado evaluated the model
attainment demonstration using a 7x7 matrix of grid cells around each
monitor site, because the model performed better in simulating the 2011
period when monitored concentrations were compared to model results in
the 7x7 matrix.\27\ This performance difference may be a result of
challenges in accurately simulating meteorological data in Colorado's
complex terrain combined with the use of a high resolution 4-km grid in
the Colorado modeling platform. It is possible that small errors in
wind speed or wind direction could result in model-simulated plumes
being offset by more than 4 km from a monitoring site. When using a 7x7
matrix of grid cells, the monitored concentration is compared to
modeled concentrations up to 12 km from the monitor site to assess
whether the model more accurately simulated the observed ozone in grid
cells close to the monitor site. Table 2 shows that when the model
attainment test is performed using the 7x7 matrix, all monitor sites
are projected to attain the 75 ppb NAAQS.
---------------------------------------------------------------------------
\27\ See Colorado OAP, TSD Part 2, Denver Metro/North Front
Range 2008 Ozone Standard Moderate Area State Implementation Plan:
Air Quality Technical Support Document (AQTSD), p. 1608.
---------------------------------------------------------------------------
Colorado also evaluated high ozone days from 2009 to 2013 that were
likely influenced by atypical activities such as wildfire or
stratospheric intrusion, but were included in the calculation of the
2011 baseline ozone design value (see Table 3; CDPHE, 2016d \28\).
While Colorado did not submit formal demonstrations under the
Exceptional Events Rule (40 CFR 50.14) for these days because they do
not affect the attainment status, which is evaluated based on 2015-2017
monitoring data, these days do affect the baseline design value and
thus affect the model projected future design value for 2017. Table 4
shows the revised 2011 baseline design value when the data likely
influenced by atypical activities are excluded, and Table 4 also shows
the results of the model attainment demonstration using both the 3x3
and 7x7 matrices for calculating the model RRF. All future design
values are below
[[Page 14813]]
the 75 ppb NAAQS using both approaches when data possibly influenced by
atypical activities are excluded in the calculation of the 2011 design
values.
---------------------------------------------------------------------------
\28\ See Colorado OAP, TSD Part 2, Analyses in Support of
Exceptional Event Flagging and Exclusion for the Weight of Evidence
Analysis, p. 1662.
---------------------------------------------------------------------------
The EPA concurs with Colorado's assessment that the model was
properly configured, met EPA performance requirements, and was
appropriately used in its application. The EPA finds that the WOE
analysis supports a determination that the area will attain the 75 ppb
ozone NAAQS by 2017.
Table 3--Ozone Monitoring Data Flagged as Exceptional Events and Excluded From the 2011 Baseline Design Value in
the Weight of Evidence Analysis
[Table 1 from CDPHE, 2016d] \29\
----------------------------------------------------------------------------------------------------------------
8-hour ozone concentrations (ppb) Exceptional event type
----------------------------------------------------------------------------------
Wildfire smoke
Date Rocky Fort Stratospheric influence
Chatfield Flats NREL Collins ozone -----------------------
North West intrusion Regional Local
----------------------------------------------------------------------------------------------------------------
April 13, 2010............... 79 ......... ......... ......... x .......... ..........
April 14, 2010............... ......... ......... ......... 75 x .......... ..........
June 7, 2011................. 84 ......... ......... ......... x .......... ..........
May 15, 2012................. ......... ......... ......... 76 ............. .......... x
June 17, 2012................ ......... ......... ......... 77 ............. .......... x
June 22, 2012................ ......... 101 83 93 ............. .......... x
July 4, 2012................. 96 92 95 76 ............. x ..........
July 5, 2012................. ......... 88 81 ......... ............. x ..........
August 9, 2012............... 98 84 88 86 ............. x ..........
August 21, 2012.............. 80 80 80 ......... ............. x ..........
August 25, 2012.............. ......... 80 ......... ......... ............. x ..........
August 31, 2012.............. ......... ......... ......... 80 ............. x ..........
August 17, 2013.............. ......... 86 84 87 ............. x ..........
----------------------------------------------------------------------------------------------------------------
Table 4--Base Year (DVB) and 2017 Future Year (DVF) Ozone Design Values (ppb) at Key Ozone Monitors With Flagged Exceptional Event Days Removed From the
2009-2013 DVB
--------------------------------------------------------------------------------------------------------------------------------------------------------
Exceptional events omitted 3x3 Exceptional events omitted 7x7
grid array (4 km) grid array (4 km)
Base year -----------------------------------------------------------------
Monitor County (2011) Final Final
DVB (ppb) RRF 2017 DVF 2017 DVF RRF 2017 DVF 2017 DVF
(ppb) (ppb) (ppb) (ppb)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Chatfield.................................. Douglas....................... 78.7 0.9453 74.4 74 0.9391 73.9 73
Rocky Flats North.......................... Jefferson..................... 78.7 0.9493 74.7 74 0.9441 74.3 74
NREL....................................... Jefferson..................... 77.7 0.9591 74.5 74 0.9442 73.4 73
Fort Collins West.......................... Larimer....................... 76.3 0.9179 70.0 70 0.9098 69.4 69
--------------------------------------------------------------------------------------------------------------------------------------------------------
G. Unmonitored Area Analysis
---------------------------------------------------------------------------
\29\ CDPHE did not identify any exceptional events in 2009 in
their weight of evidence analysis.
---------------------------------------------------------------------------
The EPA guidance recommends that an ``unmonitored area analysis''
(UAA) be performed to examine ozone concentrations in unmonitored
areas. The UAA is intended to be a means for identifying high ozone
concentrations outside of traditionally monitored locations,
particularly in nonattainment areas where modeling or other data
analyses have indicated potential high concentration areas of ozone
outside of the existing monitoring network. This review can help ensure
that a control strategy leads to reductions in ozone at other locations
that could have base case (and future) design values exceeding the
NAAQS were a monitor deployed there. The UAA uses a combination of
model output and ambient data to identify areas that might exceed the
NAAQS but that are not currently monitored. Colorado used the MATS to
perform the UAA and found estimated 2011 ozone DVBs in excess of 76 ppb
to the south, west, and northwest of Denver, stretching to Fort Collins
and then west of Fort Collins. Colorado also found that the projected
DVFs for 2017 showed all areas have values below 76 ppb. The maximum
2017 estimated design value was 75.9 ppb near the Jefferson/Boulder
County border.
H. Reasonably Available Control Technology (RACT) Analysis
1. Background
Section 172(c)(1) of the CAA, 42 U.S.C. 7502(c)(1), requires that
SIPs for nonattainment areas ``provide for the implementation of all
reasonably available control measures as expeditiously as practicable
(including such reductions in emissions from existing sources in the
area as may be obtained through the adoption, at a minimum, of
reasonably available control technology).'' The EPA has defined RACT as
the lowest emissions limitation that a particular source is capable of
meeting by the application of control technology that is reasonably
available, considering technological and economic feasibility (44 FR
53761, Sep. 17, 1979).
The EPA provides guidance concerning what types of controls could
constitute RACT for a given source category by issuing Control
Techniques Guidelines (CTG) and Alternative
[[Page 14814]]
Control Techniques (ACT) documents.\30\ States must submit a SIP
revision requiring the implementation of RACT for each source category
in the area for which the EPA has issued a CTG, and for any major
source in the area not covered by a CTG.\31\
---------------------------------------------------------------------------
\30\ See https://www.epa.gov/ozone-pollution/control-techniques-guidelines-and-alternative-control-techniques-documents-reducing
(accessed Sep. 21, 2017) for a list of EPA-issued CTGs and ACTs.
\31\ See CAA section 182(b)(2), 42 U.S.C. 7511a(b)(2)); see also
Note, RACT Qs & As--Reasonably Available Control Technology (RACT):
Questions and Answers, William Harnett, Director, Air Quality Policy
Division, EPA (May 2006), available at https://www3.epa.gov/ttn/naaqs/aqmguide/collection/cp2/20060518_harnett_ract_q&a.pdf.
---------------------------------------------------------------------------
For a Moderate, Serious, or Severe area a major stationary source
is one that emits, or has the potential to emit, 100, 50, or 25 tons
per year (tpy) or more, respectively, of VOCs or NOX (see
CAA sections 182(b), 42 U.S.C. 7511a(b); 182(c), 42 U.S.C. 7511a(c);
182(d), 42 U.S.C. 7511a(d); and 302(j), 42 U.S.C. 7602(j)). For the
DMNFR Moderate nonattainment area, a major stationary source is one
that emits, or has the potential to emit, 100 tpy or more of VOCs or
NOX. RACT can be adopted in the form of emission limitations
or ``work practice standards or other operation and maintenance
requirements,'' as appropriate.\32\ The Division identified 51 major
sources in the DMNFR area, operated by 32 companies. The EPA will be
acting on Colorado's major stationary source RACT submission in a
separate action. Colorado did not rely on any emission reductions from
major stationary sources in their 2017 modeling analysis. The remainder
of this section will address Colorado's RACT submission related to CTG
sources.
---------------------------------------------------------------------------
\32\ See Memorandum, ``Approval Options for Generic RACT Rules
Submitted to Meet the non-CTG VOC RACT Requirement and Certain
NOX RACT Requirements,'' Sally Shaver, Director, Air
Quality Strategies & Standards Division, EPA (Nov. 7, 1996),
available at https://www.epa.gov/sites/production/files/2016-08/documents/shavermemogenericract_7nov1996.pdf.
---------------------------------------------------------------------------
2. Evaluation
1. CTG Source Category Sources Addressed in This Action
As part of its May 31, 2017 submittal, the Division conducted a
RACT analysis to demonstrate that the RACT requirements for CTG sources
in the DMNFR 2008 8-hour ozone nonattainment area have been fulfilled.
The Division conducted its RACT analysis for VOC and NOX by:
(1) Identifying all categories of CTG and major non-CTG sources of VOC
and NOX emissions within the DMNFR nonattainment area; (2)
Listing the state regulation that implements or exceeds RACT
requirements for that CTG or non-CTG category; (3) Detailing the basis
for concluding that these regulations fulfill RACT through comparison
with established RACT requirements described in the CTG guidance
documents and rules developed by other state and local agencies; and
(4) Submitting negative declarations when there are no CTG or major
non-CTG sources within the DMNFR area.
The EPA has reviewed Colorado's new and revised VOC rules for the
source categories covered by the CTGs for the 2008 8-hour ozone NAAQS
listed in Tables 5 and 6 and proposes to find that these rules are
consistent with the control measures, definitions, recordkeeping, and
test methods in these CTGs and applicable EPA RACT guidance.\33\ Tables
5 and 6 contain a list of CTG source categories, EPA reference
documents, and the corresponding sections of Reg. No. 7 that fulfill
the applicable RACT requirements for EPA-issued CTGs.\34\ Colorado's
Reg. No. 7, Control of Ozone Via Ozone Precursors and Control of
Hydrocarbons Via Oil and Gas Emissions, contains SIP-approved
provisions (see 76 FR 47443, Aug. 4, 2011) that meet RACT requirements
for the source categories listed in Table 5. Reg. No. 7 also contains
general RACT provisions for the CTG source category listed in Table 6.
To meet RACT requirements for the source category in Table 6, Colorado
submitted several changes to Reg. No. 7 for adoption into its SIP (see
Section N of this notice).
---------------------------------------------------------------------------
\33\ See https://www.epa.gov/ozone-pollution/ract-information.
\34\ See The EPA's TSD for a full analysis of Colorado's rules
as they relate to EPA guidelines and available technical
information. We will be acting on the following CTG source
categories in a future action: Metal Furniture Coatings, 2007;
Miscellaneous Metal Products Coatings, 2008; Wood Furniture
Manufacturing Operations, 1996; Industrial Cleaning Solvents, 2006;
and Aerospace, 1997.
\35\ EPA Control Techniques Guidelines and Alternative Control
Techniques Documents for Reducing Ozone-Causing Emissions, https://www.epa.gov/ozone-pollution/control-techniques-guidelines-and-alternative-control-techniques-documents-reducing.
\36\ The EPA published a final CTG on October 27, 2016 to reduce
VOC emissions from the oil and gas industry (see 81 FR 74798 and
https://www.epa.gov/sites/production/files/2016-10/documents/2016-ctg-oil-and-gas.pdf). The CTG gives states two years from the date
of issuance to submit SIP revisions to address requirements of the
oil and gas CTG. Therefore, Colorado did not submit a RACT analysis
with their May 31, 2017 submission for this source category.
Table 5--SIP Approved Source Specific Rules Meeting RACT
----------------------------------------------------------------------------------------------------------------
CTG reference Chapter 7 sections
Source category in DMNFR area document \35\ Date of CTG fulfilling RACT
----------------------------------------------------------------------------------------------------------------
Bulk Gasoline Plants.............. Control of Volatile 1977.......................... Sections V, VI, and
Organic Emissions XV.
from Bulk Gasoline
Plants.
Equipment Leaks from Natural Gas/ Control of Volatile 1983.......................... Sections V and XII.
Gasoline Processing Plants. Organic Compound
Equipment Leaks from
Natural Gas/Gasoline
Processing Plants.
Leaks from Gasoline Tank Trucks Control of Volatile 1978.......................... Sections V, VI, and
and Vapor Collection Systems. Organic Compound XV.
Leaks from Gasoline
Tank Trucks and
Vapor Collection
Systems.
Leaks from Petroleum Refinery Control of Volatile 1978.......................... Sections V and VIII.
Equipment. Organic Compound
Leaks from Petroleum
Refinery Equipment.
Manufacture of Synthesized Control of Volatile 1978.......................... Sections V, IX, and
Pharmaceutical Products. Organic Emissions XIV.
from Manufacture of
Synthesized
Pharmaceutical
Products.
Oil and Natural Gas Industry \36\. Control Techniques 2016.......................... Sections V, XII,
Guidelines for the XVII, and XVIII.
Oil and Natural Gas
Industry.
Paper, Film, and Foil Coatings.... Control Techniques 2007.......................... Sections V and IX.
Guidelines for Film
Coatings.
[[Page 14815]]
Petroleum Liquid Storage in Control of Volatile 1978 (ACT 1994)............... Sections V and VI.
External Floating Roof Tanks. Organic Emissions
from Petroleum
Liquid Storage in
External Floating
Roof Tanks.
Refinery Vacuum Producing Systems, Control of Refinery 1977.......................... Sections V and VIII.
Wastewater Separators, and Vacuum Producing
Process Unit Turnarounds. Systems, Wastewater
Separators, and
Process Unit
Turnarounds.
Solvent Metal Cleaning............ Control of Volatile 1977.......................... Sections V and X.
Organic Emissions
from Solvent Metal
Cleaning.
Stage I Vapor Control Systems-- Design Criteria for 1975.......................... Sections V and VI.
Gasoline Service Stations. Stage I Vapor
Control Systems--
Gasoline Service
Stations.
Storage of Petroleum Liquids in Control of Volatile 1977.......................... Sections V and VI.
Fixed Roof Tanks. Organic Emissions
from Storage of
Petroleum Liquids in
Fixed-Roof Tanks.
Surface Coating of Cans........... Control of Volatile 1977.......................... Sections V and IX.
Organic Emissions
from Existing
Stationary Sources--
Volume II: Surface
Coating of Cans,
Coils, Paper,
Fabrics,
Automobiles, and
Light-Duty Trucks.
Surface Coating of Coils.......... Control of Volatile 1977.......................... Sections V and IX.
Organic Emissions
from Existing
Stationary Sources--
Volume II: Surface
Coating of Cans,
Coils, Paper,
Fabrics,
Automobiles, and
Light-Duty Trucks.
Surface Coating of Metal Furniture Control of Volatile 1977.......................... Section V and IX.
Organic Emissions
from Solvent Metal
Cleaning.
Surface Coating of Miscellaneous Control of Volatile 1978.......................... Sections V and IX.
Metal Parts and Products. Organic Emissions
from Existing
Stationary Sources--
Volume VI: Surface
Coating of
Miscellaneous Metal
Parts and Products.
Tank Truck Gasoline Loading Control of 1997.......................... Section V, VI and XV.
Terminals. Hydrocarbons from
Tank Truck Gasoline
Loading Terminals.
Use of Cutback Asphalt............ Control of Volatile 1977.......................... Sections V and XI.
Organic Emissions
from Use of Cutback
Asphalt.
----------------------------------------------------------------------------------------------------------------
Table 6--General Rules With Proposed SIP Revisions Meeting RACT for Source Category
----------------------------------------------------------------------------------------------------------------
Chapter 7 sections
Source category in DMNFR area CTG reference document Date of CTG fulfilling RACT
----------------------------------------------------------------------------------------------------------------
Lithographic Printing Materials and Control Techniques 2006 Sections V and XIII.
Letterpress Printing Materials. Guidelines for Offset
Lithographic Printing
and Letterpress Printing.
----------------------------------------------------------------------------------------------------------------
The Division also reviewed four ACT VOC source categories to
determine if additional VOC reductions could be achieved (see section
6.2.4 of the OAP):
1. Organic Waste Process Vents (EPA 1990, ACT);
2. Bakery Ovens (EPA 1992, ACT);
3. Industrial Wastewater Alternative Control Technology (EPA 1994,
ACT); and
4. Control of Volatile Organic Compound Emissions from Batch
Processes (EPA 1994, ACT).
These four categories were evaluated because they are not addressed
by a CTG, federal consumer product rule, or directly by a New Source
Performance Standard (NSPS) or National Emission Standard for Hazardous
Air Pollutant (NESHAP) and are not included in a State source-specific
RACT provision. Colorado found in its analysis that there are more
recent NSPS and NESHAPs that cover the source categories, and that the
State has incorporated by reference in Reg. No. 6 and implements.
Additionally, Reg. No. 7 establishes work practices and disposal
practices similar to the ACTs. Accordingly, Colorado did not identify
any additional requirements to include in their RACT analysis through
their review of the ACTs.
We have reviewed the emission limitations and control requirements
for the above source categories (Tables 5 and 6 in Reg. No. 7) and
compared them against the EPA's CTG and ACT documents, available
technical information, and guidelines. The emission limitations and
control requirements in Reg. No. 7 for the above source categories are
consistent with our guidance.
Based on available information, we find that the corresponding
sections in Reg. No. 7 provide for the lowest emission limitation
through application of control techniques that are reasonably available
considering technological and economic feasibility. For more
information, see the EPA TSD prepared in conjunction with this action.
Therefore, we propose to find that the control requirements for the
source categories identified in Tables 5 and 6 are RACT for all
affected sources in the DMNFR area under the 2008 8-hour ozone NAAQS.
I. Negative Declarations
States are not required to adopt RACT limits for source categories
for which no sources exist in a nonattainment area, and can submit a
negative declaration to that effect. Colorado has reviewed its
[[Page 14816]]
emissions inventory and determined that there are no subject sources
for source categories listed in Table 7 in the DMNFR area. We are also
unaware of any such facilities operating in the DMNFR nonattainment
area, and thus we propose to approve the negative declarations made for
the source categories in Table 7 for the DMNFR area under the 2008 8-
hour ozone NAAQS.
Table 7--Negative Declarations for CTG VOC Source Categories
------------------------------------------------------------------------
Source category negative declarations for DMNFR area
-------------------------------------------------------------------------
Auto and Light-Duty Truck Assembly Coatings (2008).
Factory Surface Coating of Flat Wood Paneling.
Fiberglass Boat Manufacturing Materials (2008).
Flat Wood Paneling Coatings (2006).
Flexible Packaging Printing Materials (2006).
Fugitive Emissions from Synthetic Organic Chemical Polymer and Resin
Manufacturing Equipment.
Graphic Arts--Rotogravure and Flexography.
Large Appliance Coatings (2007).
Large Petroleum Dry Cleaners.
Manufacture of High-Density Polyethylene, Polypropylene, and Polystyrene
Resins.
Manufacture of Pneumatic Rubber Tires.
Miscellaneous Industrial Adhesives (2008).
Oil and Natural Gas Industry (2016).
Plastic Parts Coatings (2008).
SOCMI Air Oxidation Processes.
SOCMI Distillation and Reactor Processes.
Shipbuilding/repair.
Surface Coating for Insulation of Magnet Wire.
Surface Coating of Automobiles and Light-Duty Trucks.
Surface Coating of Fabrics.
Surface Coating of Large Appliances.
Surface Coating of Paper.
------------------------------------------------------------------------
I. Reasonably Available Control Measures (RACM) Analysis
1. Background
With the attainment demonstration, Colorado submitted a
demonstration that the DMNFR area has adopted all RACM necessary to
demonstrate attainment as expeditiously as practicable, as required by
CAA section 172(c)(1), 42 U.S.C. 7502(c)(1), and 40 CFR 51.912(d). The
EPA interprets the CAA RACM provision to require a demonstration that:
(1) The state has adopted all reasonable measures (including RACT) to
meet RFP requirements and to demonstrate attainment as expeditiously as
possible; and (2) no additional measures that are reasonably available
will advance the attainment date or contribute to RFP for the area.
States should consider all available measures, including those being
implemented in other areas, but must adopt measures for an area only if
those measures are economically and technologically feasible and will
advance the attainment date or are necessary for RFP.
The EPA provided guidance interpreting the RACM requirements of
section 172(c)(1) in the General Preamble for Implementation of Title I
of the CAA of 1990.\37\ The EPA explained that states should consider
all potentially available measures to determine whether they are
reasonably available for implementation in the area, and whether they
will advance the attainment date. Id. Potentially available measures
that would not advance the attainment date for an area are not
considered RACM; likewise, states can reject potential RACM if adopting
them would cause substantial widespread and long-term adverse impacts.
Id. Local conditions, such as economics or implementation concerns, may
also be considered. To allow the EPA to determine whether the RACM
requirement has been satisfied, states should provide in the SIP
submittals a discussion of whether measures ``within the arena of
potentially reasonable measures'' are in fact reasonably available.\38\
If the measures are reasonably available, they must be adopted as RACM.
---------------------------------------------------------------------------
\37\ General Preamble, 57 FR 13498, 13560 (April 16, 1992).
\38\ ``Guidance on the Reasonably Available Control Measures
(RACM) Requirement and Attainment Demonstration Submissions for
Ozone Nonattainment Areas,'' John S. Seitz, Director, Office of Air
Quality Planning and Standards, EPA (Nov. 30, 1999).
---------------------------------------------------------------------------
2. Evaluation
To demonstrate that the area meets the RACM requirement, Colorado
identified potentially available control measures with input from
stakeholders and analyzed whether the measure would be considered a
RACM measure. In 2011, the RAQC issued a Report to the Governor that
identified and evaluated potential control strategies. Later in 2011,
the RAQC and CDPHE evaluated control measures for all source categories
that could be implemented over the next five years and included them in
a report to the RAQC Board in November 2011. Since 2011, Colorado has
adopted oil and gas regulations, implemented Clean Air--Clean Jobs Act
\39\ controls through the Regional Haze SIP, and continued alternative
fuels, transportation, and land use programs. In May 2015, the RAQC
reconvened discussions with the CDPHE and other partners to review
control strategies for the 2008 ozone SIP as well as future SIPs. Three
subcommittees made up of RAQC Board members were assembled. Areas of
analysis included stationary/areas sources, mobile sources/fuels, and
transpiration/land use/pricing/outreach. Subcommittee meetings were
open to the public, and stakeholders provided input on the topics
discussed.
---------------------------------------------------------------------------
\39\ Colo. Rev. Stat. Sec. 40-3.2-201 et seq.
---------------------------------------------------------------------------
Colorado determined that all control measures necessary to
demonstrate attainment are currently being implemented. Table 43 of
Colorado's OAP lists control measures included in Colorado's SIP as
they relate to the State's 2017 emissions inventory, photochemical
modeling in the attainment demonstration, and weight of evidence
analysis. As discussed in Chapter 7.3.2 of the OAP, the AQCC adopted
modifications to Reg. No. 11 to incorporate the portions of Larimer and
Weld Counties that are within the DMNFR nonattainment area into
Colorado's I/M program. This change was submitted as a SIP revision and
is being acted on in this action (see section J of this notice).
Additionally, Chapter 7.3.5.1. describes SIP-strengthening revisions
made to Colorado's oil and gas control program in Reg. No. 7 (see
section N of this notice). These revisions include adoption of two
``state-only'' provisions into the Ozone SIP, pertaining to (1) auto-
igniter requirements for combustion devices; and (2) audio, visual, and
olfactory inspection of storage tanks and associated equipment.
As part of the RACM analysis, CDPHE examined emission reduction
measures (see Table 44 of the OAP) being implemented in the DMNFR area
that are not included in the SIP modeling and emissions inventory
because they are voluntary or difficult to quantify. Non-federally-
enforceable emission reduction measures were evaluated for stationary
and mobile sources, lawn and garden, outreach and education, and the
transportation system. Additionally, Colorado evaluated CAA 108(f), 42
U.S.C. 7408(f) transportation measures (see Table 48 of the OAP) to
determine whether sources have applied RACM.
Emission measures that were evaluated but determined not to be RACM
are discussed in Chapter 7.5 of the OAP. Colorado used the following
criteria to determine whether measures were considered RACM:
Necessary to demonstrate attainment;
Technologically or economically feasible;
Implemented successfully in other Moderate areas;
[[Page 14817]]
Could be implemented by January 1, 2017; and
Could qualify as SIP measures by being quantifiable,
enforceable, permanent, and surplus.
Emission reduction measures evaluated for RACM were broken into
area sources, on-road mobile sources, non-road mobile sources, fuels,
transportation, alternative transportation, and land use categories.
Tables 50 and 51 of the OAP summarizes the measures evaluated and
Colorado's RACM determination for each measure. Colorado also reviewed
the EPA's Menu of Control Measures for NAAQS Implementation \40\ and
voluntary and mandatory control measures in other ozone nonattainment
areas. Table 53 of the OAP lists control measures identified, and
indicates which measures were included in the State's RACM review.
Although Colorado's analysis demonstrated that none of the additional
measures identified met the criteria for RACM, the State plans to
continue evaluating strategies in various areas including fuels, on-
and off-road vehicles, and land use.
---------------------------------------------------------------------------
\40\ The Menu of Control Measures gives state, local and tribal
air agencies information on existing emissions reduction measures,
as well as relevant information concerning the efficiency and cost
effectiveness of the measures. Available at https://www.epa.gov/air-quality-implementation-plans/menu-control-measures-naaqs-implementation.
---------------------------------------------------------------------------
In its analysis, Colorado evaluated all source categories that
could contribute meaningful emission reductions, and identified and
evaluated an extensive list of potential control measures. To determine
reasonableness and availability, the State considered the time needed
to develop and adopt regulations, and the time it would take to see the
benefit from these measures. The EPA has reviewed the RACM analysis and
finds that there are no additional RACM that would advance the Moderate
area attainment date of 2018 for the DMNFR nonattainment area.
Therefore, the EPA proposes to approve Colorado's Moderate area RACM
SIP for the DMNFR Moderate nonattainment area.
J. Motor Vehicle Inspection and Maintenance Program (I/M) Program
1. Background
As a Moderate ozone nonattainment area, Colorado is required to
implement an I/M program. Colorado's Reg. No. 11 is entitled ``Motor
Vehicle Emissions Inspection Program'' and addresses the implementation
of the State's I/M program. Under Reg. No. 11 and state law (5 CCR
1001-13), all eligible automobiles registered in the Automobile
Inspection and Readjustment (AIR) program area (the current nine-county
AIR program area is depicted in Chapter 8, Figure 27, page 8-3 of the
OAP) are subject to periodic emissions inspection. Currently there is
an exemption from emissions inspection requirements for the first seven
model years. Thereafter, an On-Board-Diagnostics (OBD) vehicle computer
inspection is conducted during the first two inspection cycles
(vehicles 8 through 11 model years old). Vehicles older than 11 model
years are given a dynamometer-based IM240 test for 1982 and newer
light-duty gasoline vehicles \41\ and a two-speed idle test (TSI) \42\
for 1981 and older light-duty gasoline vehicles. To improve motorist
convenience and reduce program implementation costs, the State also
administers a remote sensing-based ``Clean Screen'' program component
of the I/M program. Remote sensing is a method for measuring vehicle
emissions, while simultaneously photographing the license plate, when a
vehicle passes through infrared or ultraviolet beams of light. Owners
of vehicles meeting the Clean Screen criteria are notified by the
respective County Clerk that their vehicle has passed the motor vehicle
inspection process and are exempt from their next regularly scheduled
IM240 test.\43\
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\41\ See 40 CFR part 51, subpart S for a complete description of
EPA's IM240 test. The IM240 test is essentially an enhanced motor
vehicle emissions test to measure mass tailpipe emissions while the
vehicle follows a computer generated driving cycle trace for 240
seconds and while the vehicle is on a dynamometer.
\42\ See 40 CFR part 51, subpart S for a complete description of
EPA's two-speed idle test. The two-speed idle test essentially
measures the mass tailpipe emissions of a stationary vehicle; one
reading is at a normal idle of approximately 700 to 800 engine
revolutions per minute (RPM) and one reading at 2,500 RPM.
\43\ The Clean Screen program component of Reg. No. 11 was
originally approved for implementation in the Denver area with the
EPA's approval of the original Denver carbon monoxide (CO)
redesignation to attainment and the related maintenance plan. See 66
FR 64751 (Dec. 14, 2001). The Clean Screen criteria approved in 2001
required two valid passing remote sensing readings, on different
days or from different sensors and within a twelve-month period.
Colorado revised Reg. No. 11 to expand the definition and
requirements for a ``clean-screened vehicle'' to also include
vehicles identified as low-emitting vehicles in the state-determined
Low Emitting Index (LEI) that have one passing remote sensing
reading, before the vehicle's registration renewal date. These
improvements and other associated revisions to the Clean Screen
program were approved by the EPA on October 21, 2016. 81 FR 72720.
---------------------------------------------------------------------------
2. Evaluation
The AIR program and Reg. No. 11 were expanded into portions of
Larimer and Weld counties in the Colorado 2009 Legislative session,
with the passage of Senate Bill 09-003. The startup date of the I/M
program in these two counties was November 1, 2010. The purpose of this
expansion of the AIR program and Reg. No. 11 into portions of Larimer
and Weld counties was to further reduce vehicle emissions of
NOX and VOC ozone precursors in the 2008 8-hour ozone
nonattainment area. The DMNFR was then only classified as a Marginal
ozone nonattainment area, and an I/M program was not required in
Larimer and Weld counties. Therefore, the State decided to make this
portion of the I/M program, for these two counties, a ``State-only''
provision, and not to submit it as a SIP revision.
With the reclassification of the DMNFR nonattainment area to
Moderate for the 2008 8-hour ozone NAAQS, and in light of the
associated CAA requirements, the State chose to submit the I/M program
in Larimer and Weld counties into the federal SIP. Adding these
requirements into the federal SIP required several minor revisions,
which were adopted by the Colorado AQCC on November 17, 2016, and
submitted to the EPA on May 31, 2017. These revisions involved changes
to ``PART A: General Provisions, Area of Applicability, Schedules for
Obtaining Certification of Emissions Control, Definitions, Exemptions,
and Clean Screening/Remote Sensing.'' Specifically, definition number
43 was modified to remove the notation that the ``North Front Range
Area'' was a State-only program and not included in the SIP. In
addition, Part A, section V, ``Expansion of The Enhanced Emissions
Program to the North Front Range Area,'' was modified to remove the
notation that the I/M program was only a State-only program for
portions of Larimer and Weld counties and not part of the SIP. By
making these changes to Part A of Reg. No. 11, and submitting them for
approval by the EPA into the federal SIP, the State made the I/M
program in portions of Larimer and Weld counties federally enforceable.
Incorporating the formerly State-only portions of the I/M program into
the SIP permitted Colorado to include the motor vehicle emissions
reductions received from operation of the AIR program in these areas of
Larimer and Weld counties in the DMNFR attainment demonstration.
Based on our review and as discussed above, we propose approval of
the submitted Reg. No. 11 SIP revisions.
[[Page 14818]]
K. Nonattainment New Source Review (NNSR)
1. Background
As a Moderate ozone nonattainment area, Colorado is required to
implement a nonattainment new source review (NNSR) program. Applicable
NNSR requirements for ozone nonattainment areas are described in CAA
section 182, 42 U.S.C. 7511a, and further defined in 40 CFR part 51,
subpart I (Review of New Sources and Modifications). Under these
requirements, new major sources and major modifications at existing
sources must achieve the lowest achievable emission rate (LAER) and
obtain emission offsets in an amount based on the specific ozone
nonattainment classification. The emission offset ratio required for
Moderate ozone nonattainment areas is 1.15 to 1. CAA section 182(b)(5),
42 U.S.C. 7511a(b)(5).
2. Evaluation
The Colorado SIP includes Regulation No. 3, Part D, Section V.A.
(Concerning Major Stationary Source New Source Review and Prevention of
Significant Deterioration, Requirements Applicable to Nonattainment
Areas). This provision requires new major sources and major
modifications at existing sources in the DMNFR area to comply with LAER
and obtain emission offsets at the Moderate classification ratio of
1.15 to 1. The EPA approved these provisions on January 25, 2016 (81 FR
3963). In addition, in their OAP, Colorado recertified that the State's
NNSR program is fully up to date with all requirements of the Marginal
designation, including offset ratios of at least 1.1 to 1. Therefore,
since the provisions in the Colorado SIP satisfy the CAA NNSR
requirements for ozone nonattainment areas classified as Marginal and
Moderate, we propose approval of this portion of the OAP.
L. Contingency Measures Plan
1. Background
Nonattainment plan provisions must provide for the implementation
of contingency measures. CAA section 172(c)(9), 42 U.S.C. 7502(c)(9).
These are specific measures to provide additional emission reductions
if a nonattainment area fails to make RFP, or to attain the NAAQS, by
the applicable date. Contingency measures must take effect without
further action by the state or the EPA. While the CAA does not specify
the type of measures or quantity of emissions reductions required, the
EPA has interpreted the CAA for purposes of the Ozone NAAQS to mean
that contingency measures should provide additional emissions
reductions of 3% of the adjusted base year inventory for the
nonattainment area (or the state may implement contingency measures
that achieve a lesser percentage that will make up the identified
shortfall in RFP or attainment). Contingency measures may include
federal measures and local measures already scheduled for
implementation, as long as their emission reductions are in excess of
those needed for attainment or to meet RFP in the nonattainment plan.
The EPA interprets the CAA not to preclude a state from implementing
such measures before they are triggered by a failure to meet RFP or
failure to attain. For more information on contingency measures, see
the General Preamble (57 FR at 13510) and the 2008 Ozone Implementation
Rule (80 FR 12264, 12285).
2. Evaluation
To meet the contingency measures requirement, the State identified
specific measures that provide emissions reductions in excess of those
needed for RFP and for attainment as contingency measures. See Chapter
10, Tables 54 and 55 of the OAP. The submitted contingency measures
consist of NOX reductions from two EGUs addressed in the
Colorado Clean Air--Clean Jobs Act and previously adopted as part of
the Colorado Regional Haze SIP. These two projects are: (1) The
retirement of Valmont Unit 5, a 184 megawatt coal fired steam turbine
located in Boulder County, and (2) switching the 352 MW coal fired
steam turbine of Cherokee Unit 4 located in Adams County from coal to
natural gas. The sources completed these projects by the end of 2017
and they will result in an additional 11 tons per day of NOX
reductions, equating to 3.4% of the 2011 base year NOX
emissions inventory. Per EPA guidance for purposes of the Ozone NAAQS,
contingency measures should achieve reductions of 3% of the baseline
emissions inventory for the nonattainment area. The State's contingency
measures therefore are consistent with Agency guidance, because they in
fact result in more than 3% reductions over the relevant baseline. The
purpose of the contingency measures is to provide for further emission
reductions to make up the shortfall needed for RFP or for attainment,
during the period in which the State and the EPA determine whether the
nonattainment plan for the area needs further revision to achieve the
NAAQS expeditiously.\44\
---------------------------------------------------------------------------
\44\ See General Preamble, section III.A.3.c (57 FR 13498 at
13511).
---------------------------------------------------------------------------
The appropriateness of relying on already-implemented reductions to
meet the contingency measures requirement has been addressed in two
federal circuit court decisions. See Louisiana Environmental Action
Network (LEAN) v. EPA, 382 F.3d 575, 586 (5th Cir. 2004), Bahr v.
United States EPA, 836 F.3d 1218 (9th Cir. 2016), cert. denied, 199 L.
Ed. 2d 525, 2018 U.S. LEXIS 58 (Jan. 8, 2018). The EPA believes that
the language of section 172(c)(9) is ambiguous with respect to this
issue, and that it is reasonable for the agency to interpret the
statutory language to allow approval of already implemented measures as
contingency measures, so long as they meet other parameters such as
providing excess emissions reductions that the state has not relied
upon to make RFP or for attainment in the nonattainment plan for the
NAAQS at issue. Until the Bahr decision, under the EPA's longstanding
interpretation of CAA section 172(c)(9), states could rely on control
measures that were already implemented (so called ``early triggered''
contingency measures) as a valid means to meet the Act's contingency
measures requirement. The Ninth Circuit decision in Bahr leaves a split
among the federal circuit courts, with the Fifth Circuit upholding the
Agency's interpretation of section 172(c)(9) to allow early triggered
contingency measures and the Ninth Circuit rejecting that
interpretation. The Tenth Circuit, in which Colorado is located, has
not addressed the issue, nor has the Supreme Court or any other circuit
court other than the Fifth and Ninth.
Because there is a split in the federal circuits on this issue, the
EPA expects that states located in circuits other than the Ninth may
elect to rely on the EPA's longstanding interpretation of section
172(c)(9) allowing early triggered measures to be approved as
contingency measures, in appropriate circumstances. The EPA's recently
revised Regional Consistency regulations pertaining to SIP provisions
authorize the Agency to follow this interpretation of section 172(c)(9)
in Circuits other than the Ninth. See 40 CFR part 56. To ensure that
early triggered contingency measures appropriately satisfy all other
relevant CAA requirements, the EPA will carefully review each such
measure, and intends to consult with states considering such measures
early in the nonattainment plan development process.
[[Page 14819]]
As shown in Table 55 of Colorado's OAP, the NOX
reductions projected through 2018 are sufficient to meet the
requirements for contingency measures, consistent with the EPA's
interpretation of the CAA to allow approval of already implemented
control measures as contingency measures in states outside the Ninth
Circuit. Therefore, we propose approval of the contingency measure
submitted by the state in the OAP.
M. Motor Vehicle Emissions Budget (MVEB)/Transportation Conformity
1. Background
Transportation conformity is required by section 176(c) of the CAA,
42 U.S.C. 7506. Conformity to a SIP means that transportation
activities will not produce new air quality violations, worsen existing
violations, or delay timely attainment of the NAAQS (CAA 176(c)(1)(B),
42 U.S.C. 7506(c)(1)(B)). The EPA's conformity rule at 40 CFR part 93,
subpart A requires that transportation plans, programs, and projects
conform to SIPs, and establishes the criteria and procedures for
determining whether or not they conform. The conformity rule requires a
demonstration that emissions from the Metropolitan Planning
Organization's (MPO) Regional Transportation Plan (RTP) and the
Transportation Improvement Program (TIP) are consistent with the MVEB
in the control strategy SIP revision or maintenance plan. 40 CFR
93.101, 93.118, and 93.124. The MVEBs are defined as the portion
allocated to mobile source emissions out of the total allowable
emissions of a pollutant defined in the SIP for a certain date for the
purpose of demonstrating attainment or maintenance of the NAAQS or for
meeting reasonable further progress milestones.\45\
---------------------------------------------------------------------------
\45\ 40 CFR 93.101; see 40 CFR 93.118 and 93.124 for criteria
and other requirements related to MVEBs. Further discussion of MVEBs
is in the preamble to the transportation conformity rule. 58 FR
62188, 62193-62196 (Nov. 24, 1993).
---------------------------------------------------------------------------
2. Evaluation
Colorado derived the MVEBs for NOX and VOCs from its
2017 DMNFR attainment demonstration, and defined the MVEBs in Chapter
11, section 11.4 of the OAP.
Table 8--2017 NOX and VOC MVEBs for DMNFR
------------------------------------------------------------------------
2017 NOX emissions
Area of applicability (tons per day) 2017 VOC emissions
(tons per day)
------------------------------------------------------------------------
Northern Subarea................ 12 8
Southern Subarea................ 61 47
---------------------------------------
Total Nonattainment Area.... 73 55
------------------------------------------------------------------------
These MVEBs are consistent with, and clearly related to, the
emissions inventory and the control measures in the SIP; are consistent
(when considered together with all other emissions sources) with
attainment of the 2008 8-hour ozone NAAQS in 2017; and satisfy the
minimum criteria at 40 CFR 93.118(e)(4). Therefore, we propose approval
of the MVEBs as reflected in Table 8. This proposed approval applies to
the Northern Subarea and Southern Subarea MVEBs as well as the Total
Nonattainment Area MVEBs. The transportation conformity subareas are
defined in Chapter 11, section 11.3 of the OAP and are listed below.
The Northern Subarea is the area denoted by the ozone
nonattainment area north of the Boulder County northern boundary and
extended through southern Weld County to the Morgan County line. This
area includes the North Front Range MPO's (NFRMPO) regional planning
area as well as part of the Upper Front Range Transportation Planning
Region (TPR) in Larimer and Weld counties.
The Southern Subarea is the area denoted by the ozone
nonattainment area south of the Boulder County northern boundary and
extended through southern Weld County to the Morgan County line. This
area includes the nonattainment portion of the Denver Regional Council
of Governments (DRCOG) regional planning area and the southern Weld
County portion of the Upper Front Range TPR.
Both subareas are further described in the OAP in Figure
29, ``8-hour Ozone Nonattainment Area Subareas.''
In addition to proposing approval of the MVEBs, we also propose to
approve the process described in Chapter 11, section 11.6 in the OAP
for the use of the Total Nonattainment Area MVEBs or the subarea MVEBs
for the respective MPOs to determine transportation conformity for
their respective RTP. As described in section 11.6 of Colorado's OAP,
the OAP identifies subarea MVEBs for DRCOG and the NFRMPO. These SIP-
identified subarea MVEBs allow either MPO to make independent
conformity determinations for the applicable subarea MVEBs whose
frequency and timing needs for conformity determinations differ. As
noted in section 11.6, DRCOG and the NFRMPO may switch from using the
Total Nonattainment Area MVEBs to using the subarea MVEBs for
determining conformity. To switch to use of the subarea MVEBs (or to
subsequently switch back to use of the Total Nonattainment Area MVEBs)
DRCOG and the NFRMPO must use the process described in the DMNFR OAP in
section 11.6 (see pages 11-5 and 11-6). This process of demonstrating
transportation conformity to the total or subarea area MVEBs, as
described in section 11.6 of the OAP, was previously approved by the
EPA for the Denver Ozone Plan for the 1997 8-hour ozone NAAQS (76 FR
47443, Aug. 5, 2011). Now, as to the 2008 8-hour standard, the EPA
finds that this process remains consistent with the CAA and with
applicable EPA regulations, and therefore proposes to approve it.
N. SIP Control Measures
1. Background
This section describes revisions to Colorado Reg. No. 7 submitted
as a part of the SIP, including emission control requirements for oil
and gas operations, graphic arts and printing processes, stationary and
portable engines, and other combustion equipment. The revisions also
establish RACT requirements for emission points at major sources of VOC
and NOX in the DMNFR area.
[[Page 14820]]
Reg. No. 7 contains various requirements intended to reduce
emissions of ozone precursors. These are in the form of specific
emission limits applicable to various industries and general RACT
requirements.\46\ The EPA approved the repeal and re-promulgation of
Reg. No. 7 in 1981 (46 FR 16687, March 13, 1981) and has approved
various revisions to parts of Reg. No. 7 over the years. In 2008, the
EPA approved revisions to the control requirements for condensate
storage tanks in Section XII (73 FR 8194, Feb. 13, 2008). The EPA later
approved revisions to Reg. No. 7, Sections I through XI and Section
XIII through XVI (76 FR 47443, Aug. 5, 2011). Most recently, the EPA
approved Reg. No. 7 revisions to control emissions from rich burn
reciprocating internal combustion engines in Section XVII.E.3.a (77 FR
76871, Dec. 31, 2012).
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\46\ On October 20, 2016, the EPA issued final CTGs for existing
sources in the oil and natural gas industry (see https://www.epa.gov/sites/production/files/2016-10/documents/2016-ctg-oil-and-gas.pdf). In accordance with the timing set forth in the CTG,
Colorado has two years from this date (October 20, 2018) to submit
SIP revisions to EPA to update RACT for this source category (see
Memo: Implementing Reasonably Available Control Technology
Requirements for Sources Covered by the 2016 Control Techniques
Guidelines for the Oil and Natural Gas Industry, available within
the docket for this action).
---------------------------------------------------------------------------
Colorado submitted proposed revisions to Reg. No. 7 on May 5, 2013,
and submitted revised Reg. No. 7 revisions with the OAP on May 31,
2017. The 2017 revisions address EPA concerns about the May 5, 2013
submittal regarding monitoring, recordkeeping, and reporting
requirements in Sections XII.H.5 and XII.H.6 and other concerns in
Sections XII.C.1.c, XII.C.1.d, XII.C.2.a.(ii)(B), XII.E.3, and XII.H.4.
The May 31, 2017 submittal also includes changes to Reg. No. 7
regarding RACT requirements for lithographic and letterpress printing,
industrial cleaning solvents, and major sources of VOCs or
NOX. Colorado made substantive revisions to certain limited
parts of Reg. No. 7, particularly Sections X, XII, XIII, XVI and new
Section XIX., and also made non-substantive revisions to numerous parts
of the regulation. For ease of review, Colorado submitted the full text
of Reg. No. 7 as a SIP revision (with the exception of provisions
designated ``State Only''). The EPA is only seeking comment on
Colorado's proposed substantive changes to the SIP-approved version of
Reg. No. 7, which are described below. We are not seeking comment on
incorporation into the SIP of the revised portions of the regulation
that were previously approved into the SIP and have not been
substantively modified by the State as part of this submission.
As noted above, Colorado designated various parts of Reg. No. 7
``State Only'' and in Section I.A.1.c indicated that sections
designated State Only are not federally enforceable. The EPA concludes
that provisions designated State Only have not been submitted for EPA
approval, but for informational purposes. Hence, the EPA is not
proposing to act on the portions of Reg. No. 7 designated State Only
and this proposed rule does not discuss them further except as relevant
to discussion of the portions of the regulation that Colorado intended
to be federally enforceable.
2. Evaluation
a. Analysis of Reg. No. 7 Changes in May 5, 2013 Submittal
The EPA proposes to approve the changes made to Section XII.D
(currently SIP-approved Section XII.A.2) with Colorado's May 5, 2013
submission.\47\
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\47\ All other sections of Reg. No. 7 addressed in the May 5,
2013 submission have been superseded by the State's May 31, 2017
submission. The EPA is not acting on the superseded earlier
submissions.
---------------------------------------------------------------------------
(i) Section XII.D
Section XII.D contains an introductory statement regarding the
control requirements for atmospheric condensate storage tanks. The
changes to current SIP-approved Section XII.A.2 are minor and do not
change the substance of the corresponding EPA-approved provisions.
a. Section XII.D.2.a
Section XII.D.2.a contains the system-wide control requirements for
condensate storage tanks. Owners and operators of storage tanks that
emit greater than two tons per year of actual uncontrolled VOCs are
subject to the requirements in Section XII.D.2.a. The current SIP
provides for a weekly 75% system-wide VOC reduction during the summer
ozone season beginning May 1, 2007, and 78% beginning May 1, 2012. The
revised section significantly increases the summer ozone season weekly
VOC reduction requirements from the current EPA-approved requirements,
to 85% beginning in 2010 (revised Section XII.D.2.a.(ix)) and 90%
beginning May 1, 2011, and each year thereafter (revised Section
XII.D.2.a.(x)). The revised Section XII.D.2.a provides more stringent
emission reductions than the current SIP and therefore serves to
strengthen the SIP.
b. Analysis by Section of Reg. No. 7 Changes in May 31, 2017 Submittal
(i) Sections I, II, VI, VII, VIII, and IX
The changes in these sections are clerical \48\ in nature and do
not affect the substance of the requirements. Therefore, we propose to
approve the changes.
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\48\ When we describe changes as clerical in this proposed
action, we are referring to changes like section renumbering,
alphabetizing of definitions, minor grammatical and editorial
revisions, and changes in capitalization.
---------------------------------------------------------------------------
(ii) Section X
Section X. regulates VOC emissions from the use of cleaning
solvents. We will be acting on Section X revisions in a future action.
(iii) Section XII
Section XII contains emission control requirements for VOCs from
oil and gas operations. The State originally reorganized Section XII
and included additional control requirements for condensate tanks in
their June 18, 2009 SIP submittal. The EPA disapproved revisions to
Reg. No. 7, Section XII in our August 5, 2011 rulemaking (76 FR 47443)
because of deficiencies in Colorado's proposed revisions (see 75 FR
42355, July 21, 2010). The State once again submitted proposed
revisions to Section XII with their May 31, 2017 submissions. Table 9
outlines the reorganization/renumbering in Colorado's proposed
revisions to Section XII:
Table 9--Reorganization/Renumbering in Colorado's Proposed Revisions to
Section XII
------------------------------------------------------------------------
Corresponding EPA-
Proposed section XII numbering approved section Subject
XII numbering
------------------------------------------------------------------------
XII.A......................... XII.A............ Applicability.
XII.A.1....................... XII.A............ Applicability.
XII.A.1.a through d.(ii)...... XII.A.1.a through Applicability.
c.
XII.A.2....................... XII.D.4.......... Exception to
applicability of oil
refineries.
[[Page 14821]]
XII.A.3....................... None............. Applicability for
natural gas-
processing plants
and certain natural
gas compressor
stations. Subject to
Section XII.G. and
XII.I.
XII.A.4....................... None............. Applicability for
certain glycol
natural gas
dehydrators, natural
gas compressor
stations, drip
stations, or gas
processing plants.
Only subject to
XII.B and XII.H.
XII.A.5....................... XII.A.8.......... Exception to
applicability based
on uncontrolled
actual VOC emissions
threshold of 30 tons
per year.
XII.B......................... None............. Definitions specific
to section XII.
XII.B.1, 2, 3, 9, and 14...... XII.D.5, 8, 6, 1, Definitions of
and 9.. various terms.
XII.B.4, 5, 6, 7, 8, 10, 11, None............. Definitions of
and 12. various terms.
XII.C......................... XII.D............ General provisions to
section XII.
XII.C.1....................... None............. General requirements
for air pollution
control equipment,
leaks.
XII.C.1.a..................... XII.D.2.a........ General requirements
for operation/
maintenance of
control equipment.
XII.C.1.b..................... XII.D.2.b........ General requirement
to minimize leakage
of VOCs.
XII.C.1.c..................... XII.A.7 and Air pollution
XII.A.4.h. control--equipment
control efficiency.
Failure to operate
and maintain control
equipment at
indicated locations
is a violation.
XII.C.1.d..................... XII.D.2.c........ Requirements for
combustion devices.
XII.C.1.e..................... None............. State-only
requirements related
to combustion
devices.
XII.C.1.e.(iii)............... None............. Auto-igniter
requirements for
combustion devices.
XII.C.2 and XII.C.2.a......... XII.D.3.......... Emission factors for
emission estimates.
XII.D......................... XII.A.2.......... Emission control
requirements for
condensate tanks.
XII.D.2.a.(i) through (x)..... XII.A.2.a through System-wide control
h. requirements for
condensate storage
tanks.
XII.D.2.b..................... XII.A.9.......... Alternative emission
control equipment.
XII.E......................... XII.A.3.......... Monitoring.
XII.E.1....................... None............. Requirements for
control equipment
other than a
combustion device.
XII.E.2, XII.E.2.a and b...... XII.A.3.a and b.. Checks for combustion
devices.
XII.E.3....................... XII.A.4.j........ Documentation of
inspections.
XII.E.3.a.-e.................. XII.A.3.c.-f..... Requirements for the
weekly check.
XII.F......................... XII.A.4 and Recordkeeping and
XII.A.5. reporting
requirements.
XII.F.1 and 2................. XII.A.10 and 11.. Marking of AIRS
numbers on tanks.
XII.F.3....................... XII.A.4.......... Introductory language
for recordkeeping.
XII.F.3.a(i).................. XII.A.4.a........ List of tanks and
production volumes.
XII.F.3.a(ii) and (iii)....... XII.A.4.b and c.. Listing of emission
factors and location
and control
efficiencies.
XII.F.3.a(iv)................. XII.A.4.d.i...... List weekly and
monthly production
values. Describes
how to determine the
averages.
XII.F.3.a(v)-(vii)............ XII.A.4.d.ii-iv.. List weekly and
monthly uncontrolled
actual and
controlled actual
emissions by tank
and system-wide.
List percent
reductions weekly
and monthly.
XII.F.3.a(viii)............... XII.A.4.e........ Note any downtime and
account for it.
XII.F.3.a(ix)-(x)............. XII.A.4.f-g...... Maintaining and
mailing of
spreadsheet.
XII.F.3.b-d................... XII.A.4.h-j...... Failure to have
control equipment as
indicated on spread
sheet is violation.
Retain spread sheets
for five years.
Maintain records of
inspections.
XII.F.4....................... XII.A.5.......... Reporting for system-
wide requirements.
XII.F.4.a..................... XII.A.5.a........ List tanks and
production volumes.
XII.F.4.b-c................... XII.A.5.b-c...... List emission factor
and location and
control efficiency.
XII.F.4.d..................... XII.A.5.d........ What different
reports must show
based on time of
year. Emissions from
individual tanks
must be included.
XII.F.4.e..................... XII.A.5.e........ What different
reports must show
based on time of
year. Emissions
system-wide.
XII.F.4.f..................... XII.A.5.f........ What different
reports must show
based on time of
year. Percent
reduction system-
wide.
XII.F.4.g..................... XII.A.5.g........ Note shutdown of
control equipment
and account for same
in totals.
XII.F.4.h..................... XII.A.5.h........ State whether
required reductions
were achieved.
XII.F.4.i..................... XII.A.5.i........ Include any
information
requested by the
Division.
XII.F.4.j..................... XII.A.5.j........ Retention period.
XII.F.4.k..................... XII.A.5.k........ Additional reporting,
monthly reporting of
problems and
corrective actions.
XII.F.4.l..................... XII.A.5.l........ Before ozone season,
identify tanks being
controlled to meet
system-wide control
requirements.
XII.F.5....................... XII.A.6.......... Exemption from record-
keeping and
reporting
requirements for
natural gas
compressor stations
and drip stations
authorized to
operate pursuant to
a construction or
operating permit.
XII.G......................... XII.B............ Requirements for gas
processing plants.
Introductory
statement.
XII.G.1....................... XII.B.1.......... Part 60 leak
detection applies.
XII.G.2....................... XII.B.2.......... Applicability of
control equipment.
XII.G.3....................... XII.B.3.......... Compliance date for
existing plants.
XII.G.4....................... XII.B.4.......... Compliance date for
new plants.
[[Page 14822]]
XII.H.1....................... XII.C............ Requirements that
apply to vents from
gas-condensate-
glycol separators or
tanks on glycol
natural gas
dehydrators at an
oil and gas
exploration and
production
operation, natural
gas compressor
station, drip
station or gas-
processing plant.
XII.H.3....................... XII.C............ Control requirements
application.
XII.H.3.b..................... XII.C............ Control requirements
application.
XII.H.4....................... None............. Method for
calculating
emissions from
vents.
XII.H.5....................... None............. Monitoring and
recordkeeping
requirements for
glycol natural gas
dehydrators.
XII.H.6....................... None............. Reporting
requirements for
glycol natural gas
dehydrators.
XII.I......................... ................. Natural gas
compressor and drip
station section XII
requirements
exemptions.
------------------------------------------------------------------------
Section XII revises requirements for system-wide reductions in
condensate storage tank VOC emissions. The current EPA-approved Section
XII requires that uncontrolled actual condensate tank VOC emissions in
the DMNFR area be reduced on a weekly basis during the summer ozone
season by 75% system-wide beginning May 1, 2007, and 78% beginning May
1, 2012. Revised Section XII (Section XII.D.2) requires an 81% system-
wide reduction in uncontrolled actual weekly condensate tank VOC
emissions during the summer ozone season beginning May 1, 2009, an 85%
reduction beginning May 1, 2010, and a 90% reduction beginning May 1,
2011. Section XII proposed revisions also include combustion device
auto-igniter requirements, a leak detection and repair (LDAR) program
applicable to natural gas processing plants, and emission reductions
from glycol natural gas dehydrators requirements. Below, we describe in
detail Colorado's proposed revisions to Section XII and the basis for
our proposed approval of such revisions.
a. Section XII.A
Section XII.A defines the applicability of Section XII requirements
and is consistent with the current EPA-approved applicability
provisions in Section XII.
b. Section XII.B
Section XII.B contains definitions specific to Section XII. The
substance of the definitions in Sections XII.B.1, 2, 3, 9, 12, and 14
is unchanged from the definitions contained in SIP approved Sections
XII.D.1 and XII.D.5 through 9. The other definitions in revised Section
XII.B define the following terms that are used in Section XII: Auto-
igniter, calendar week, condensate storage tank, downtime, existing,
modified or modification, and new. The definitions are clear,
straightforward, and accurate.
The definition of existing is only pertinent to State-only
provisions and thus has no meaning for our SIP action.
c. Section XII.C.1
Section XII.C.1 contains general requirements for air pollution
control equipment and prevention of leakage. Section XII.C.1.e includes
a provision requiring all combustion devices installed on or after
January 1, 2017, used to control emissions of VOCs to be equipped with
an operational auto-igniter. This new provision strengthens Colorado's
SIP. The remaining Section XII.C.1 revisions do not change the
substance of the corresponding EPA-approved provisions.
d. Section XII.C.2
Section XII.C.2 describes the emission factors to be used for
estimating emissions and emissions reductions from condensate storage
tanks under Section XII. In the current EPA-approved SIP (Sections
XII.D.3.b and 3.b.i), the emission factors to be used are specified for
condensate storage tanks at natural gas compressor stations, natural
gas drip stations, and gas-condensate-glycol separators. In revised
Sections XII.C.2.a.(ii) and a.(ii)(A), Colorado deleted the reference
to gas-condensate-glycol separators. Revised Section XII.H still
requires a 90 percent reduction in emissions at certain gas-condensate-
glycol separators. Emission calculation and monitoring and
recordkeeping requirements established in XII.H.4, 5, and 6 provide for
enforcement and compliance of emission reduction requirements in
XII.H.1.
At the EPA's request, Colorado deleted the EPA approval requirement
in XII.C.2.a.(ii)(B). The EPA is not involved in formal approval of
site-specific emission factors and the EPA was concerned with previous
SIP-approved language in XII.D.b.3.ii, which allowed for default SIP
approval if the EPA did not object within 30 days to a test method
approved by the Division to determine an emission factor.
e. Section XII.D
Section XII.D contains an introductory statement regarding the
control requirements for atmospheric condensate storage tanks. The
changes to current SIP-approved Section XII.A.2 are minor and do not
change the substance of the corresponding EPA-approved provisions.
f. Section XII.D.2.a
Section XII.D.2.a. contains the system-wide control requirements
for condensate storage tanks and adds an introductory statement
clarifying requirements for installing air pollution control equipment
on condensate storage tanks to achieve reductions outlined in Sections
XII.D.2.a.(i) through (x). The current SIP provides for a weekly 75%
system-wide VOC reduction during the summer ozone season beginning May
1, 2007, and 78% beginning May 1, 2012. The revised section
significantly increases the summer ozone season weekly VOC reduction
requirements from the current EPA-approved requirements, to 85%
beginning in 2010 (revised Section XII.D.2.a.(ix)) and 90% beginning
May 1, 2011, and each year thereafter (revised Section XII.D.2.a.(x)).
The revised Section XII.D.2.a. provides more stringent emission
reductions than the current SIP and therefore strengthens the SIP.
g. Section XII.D.2.b
Section XII.D.2.b is a renumbered version of current EPA-approved
Section XII.A.9. This section contains a process for approval of
alternative emissions control equipment and pollution prevention
devices and processes. Among other things, the section specifies
requirements for public participation and EPA approval. Colorado did
not change the substance
[[Page 14823]]
of this provision, but simply renumbered it from Section XII.A.9 to
XII.D.2.b.
h. Section XII.E
Section XII.E contains the monitoring requirements that are
currently specified in EPA-approved Sections XII.A.3 and XII.A.4.j.
Colorado retained the basic requirement for weekly inspections or
monitoring. Colorado improved certain provisions. For example, under
revised Section XII.E, an owner or operator must ensure not only that
the control equipment is operating, but that it is operating properly.
Revised Section XII.E.1 adds a requirement that owners or operators of
control equipment other than a combustion device follow manufacturer's
recommended maintenance and inspect the equipment to ensure proper
maintenance and operation. Revised Section XII.E.3 (current XII.A.4.j)
adds a requirement that the owner or operator document any corrective
actions taken and the name of the individual performing the corrective
actions resulting from a weekly inspection. Revised Sections XII.E.3.a
through d. add the requirement that the owner or operator not only
perform certain checks, but that the owner or operator document those
checks. Revised Section XII.E.3.e adds a new requirement for owners or
operators to conduct and document audio, visual, and olfactory
inspections during liquids unloading events for tanks with uncontrolled
actual emissions of VOCs equal to or greater than six tons per year.
These provisions strengthen the SIP.
i. Section XII.F
Section XII.F contains recordkeeping and reporting requirements
that are currently in EPA-approved Sections XII.A.4 and XII.A.5. The
recordkeeping requirements specify information that must be listed on a
spreadsheet that owners/operators must maintain. Many of the provisions
are identical to those in the current EPA approved SIP.
In Sections XII.F.1 through 4, Colorado made a few substantive
changes to the existing provisions. In revised Section XII.F.3,
Colorado added a sentence requiring the owner or operator to track VOC
reductions on a calendar weekly and calendar monthly basis to
demonstrate compliance with system-wide VOC reduction requirements.
Colorado also specified that owners/operators would need to use the
Division-approved spreadsheet to track VOC emissions and reductions.
These changes are reasonable and consistent with CAA requirements.
j. Section XII.F.3
In revised Section XII.F.3.a(i), which requires the spreadsheet to
list the condensate storage tanks subject to Section XII and the
production volumes for each tank, Colorado specified that the
spreadsheet must list monthly production volumes. Revised Section
XII.F.3.a(iv) also requires the owner/operator to list the production
volume for each tank as a weekly and monthly average based on the most
recent measurement available and specifies the method for pro-rating
that measurement over the weekly or monthly period.
Revised Section XII.F.3.c requires owners/operators to retain a
copy of each weekly and monthly spreadsheet for five years instead of
the three years required by current EPA-approved Section XII.A.4.i.
Revised Section XII.F.3.d requires owners/operators to maintain records
of inspections required by Sections XII.C. and XII.E. for five years.
k. Section XII.F.4
In revised Section XII.F.4, Colorado made minor changes to current
EPA-approved reporting requirements. Revised Section XII.F.4.a requires
the semiannual reports to list all condensate storage tanks subject to
or used to comply with the system-wide reduction requirements, not just
the tanks that are subject to such requirements. This reflects the
change to the regulation that allows owners/operators to control tanks
with emissions below the Air Pollutant Emission Notice (APEN) filing
levels to meet the percent reduction requirement in Section XII.D.2. In
revised Sections XII.F.4.d through f. Colorado clarified that the April
30 reports must include the monthly emissions information and the
November 30 reports must include the weekly emissions information. In
revised Section XII.F.4.g, Colorado deleted the requirement in current
EPA-approved Section XII.A.5.g that the owner/operator note in the
report list ``the date the source believes the shutdown [of control
equipment] occurred, including the basis for such belief.'' This
deletion is reasonable because the owner/operator is not likely to be
able to make an accurate estimate of the date the shutdown occurred,
and, thus, the information is not likely to be meaningful in an
enforcement context.
In revised Section XII.F.4.h, Colorado clarified monthly versus
weekly reporting requirements. In revised Section XII.F.4.j, Colorado
increased the retention period for reports from 3 years to 5 years.
These changes are consistent with CAA requirements.
l. Section XII.F.5
Section XII.F.5 contains an exemption from Section XII's record-
keeping and reporting requirements for owners/operators of natural gas
compressor stations (NGCSs) or natural gas drip stations (NGDSs)
authorized to operate pursuant to a construction permit or Title V
operating permit if certain conditions are met. In our August 5, 2011
(76 FR 47443) proposed rulemaking, we expressed our concern with
Colorado's removal of one of the conditions for this exemption
contained in current EPA-approved Section XII.A.6. Colorado's current
submission reinstates this exemption. Colorado therefore did not change
the substance of this provision, but simply renumbered it from Section
XII.A.6 to section XII.F.5, made minor typographical corrections, and
updated section references.
m. Section XII.G
Section XII.G specifies the control requirements applicable to gas
processing plants and corresponds to current EPA-approved Section
XII.B. The EPA-approved Section XII.B requires gas processing plants to
meet the requirements in Section XII.B specifically applicable to such
plants as well as the requirements in current EPA-approved Section
XII.C, pertaining to certain still vents and vents from gas condensate-
glycol separators, and Section XVI, pertaining to emissions from
stationary and portable engines. Revised Section XII.G requires gas
processing plants to additionally comply with the requirements of
revised Section XII.B, the definitions section, revised Sections
XII.C.1.a and XII.C.1.b, which specify maintenance and design
requirements for control equipment and the obligation to minimize
leakage of VOCs to the atmosphere, and revised Section XII.H, which
specifies control requirements for still vents and vents flash
separators or flash tanks on glycol natural gas dehydrators located at
oil and gas exploration and production operations, natural gas
compressor stations, drip stations, or gas-processing plants. It
appears that this change would strengthen the requirements applicable
to gas-processing plants.
n. Section XII.G.1
Section XII.G.1 specifies that NSPS leak detection and repair
requirements apply regardless of the date of construction of the
facility, and adds a reference to LDAR requirements in NSPS OOOO and
OOOOa. Colorado made no substantive changes to this provision.
[[Page 14824]]
o. Section XII.G.2
Section XII.G.2 is a renumbered and revised version of current EPA-
approved Section XII.B.2. This provision specifies the applicability
threshold for installation of control equipment at gas processing
plants and the efficiency requirement for the control equipment. The
EPA approved current Section XII.B.2 on August 19, 2005 (70 FR 48652).
In current EPA-approved Section XII.B.2, the requirement to install
control equipment is triggered if condensate storage tank throughput
exceeds ``APEN de minimis levels,'' as set in the State's Reg. No. 3,
Part A, Section II.D. That regulation in turn specified that in
attainment areas, the APEN requirement applied to sources with
uncontrolled emissions of any criteria pollutant of less than two tons
per year. For nonattainment areas, this de minimis threshold dropped to
one ton per year. When the State submitted and the EPA approved section
XII.B.2, the 8-hour ozone control area was still in attainment,\49\ and
therefore the APEN de minimis level referenced in Section XII.B.2 was
two tons per year.
---------------------------------------------------------------------------
\49\ The 1997 8-hour ozone NAAQS nonattainment designation for
the DMNFR became effective November 20, 2007 (72 FR 53952 and 53953,
September 21, 2007).
---------------------------------------------------------------------------
In 2008, along with renumbering section XII.B.2 to XII.G.2,
Colorado revised the threshold in this provision to accurately reflect
the original two-ton-per-year level.\50\ The two-ton threshold in
revised Section XII.G.2, therefore, would capture the same tanks as
were being captured at the time Section XII.B.2 was approved into the
State's SIP, and would also provide clarity as to the SIP requirements
by removing a cross-reference that is arguably ambiguous. We propose to
find that the revised section XII.G.2 is approvable because it
clarifies the applicability threshold for determining which condensate
storage tanks are subject to control requirements.
---------------------------------------------------------------------------
\50\ Colorado submitted this to the EPA as a SIP revision on
July 18, 2009, but we disapproved the proposed revisions to section
XII, including XII.G.2, with our August 11, 2011 rulemaking (76 FR
47443). In our proposal, as to XII.G.2. we stated that our proposed
disapproval rested in part on uncertainty about the effect of the
change from ``APEN de minimis levels'' to ``greater than or equal to
two tons per year,'' and in part on a revised control efficiency
requirement that introduced a twelve-month averaging period. (75 FR
42346, 42358, July 21, 2010). Colorado has since removed the twelve-
month averaging period, and as described in this notice we have
concluded that the effect of the change to a specific two-ton-per-
year threshold has the effect of clarifying the SIP, not weakening
it. Accordingly, we are proposing to find that this provision is
approvable.
---------------------------------------------------------------------------
p. Section XII.G.3
Section XII.G.3 specifies the compliance date for existing natural
gas processing plants. Colorado did not change the substance of this
provision.
q. Section XII.G.4
Revised Section XII.G.4, which specifies the compliance date for
new gas processing plants, adds a reference to Section XII.G. Colorado
did not change the substance of this provision.
r. Section XII.H.1
Section XII.H.1. specifies control requirements in current EPA-
approved Section XII.C. for still vents and vents from gas-condensate-
glycol separators on glycol natural gas dehydrators at oil and gas
exploration and production operations, natural gas compressor stations,
drip stations, or gas-processing plants. Colorado did not change the
substance of this provision.
s. Section XII.H.3
XII.H.3 specifies that control requirements in Sections XII.H.1 and
2 apply where uncontrolled emissions of VOCs from glycol gas
dehydrators are equal to or greater than one ton per year and the sum
of actual uncontrolled emissions of VOCs from any single or grouping of
glycol natural gas dehydrators at a single source is greater than 15
tons per year. Revised Section XII.H clarifies current EPA-approved
Section XII.C's applicability threshold for control requirements.
t. Section XII.H.4
Section XII.H.4 adds a requirement for calculating emissions from
still vents and vents from flash separators or flash tanks on glycol
natural gas dehydrators to ensure the 90 percent VOC emission reduction
requirements in XII.H.1 are achieved. This provision strengthens the
SIP.
u. Section XII.H.5
Section XII.H.5. adds monitoring and recordkeeping requirements for
enforcement and compliance of emission reduction requirements in
XII.H.1. XII.H.5.a requires owners and operators of natural gas
dehydrators to check on a weekly basis that condensers and air
pollution equipment control equipment are operating properly, and to
document dates of inspections, problems observed, and descriptions and
dates of corrective actions taken. XII.H.5.b requires owners and
operators to check and document on a weekly basis that pilot lights on
combustion devices are lit, that valves for piping gas to pilot lights
are open, and to check for smoke. XII.H.5.c requires owners and
operators to document any maintenance of the condenser or air pollution
control equipment consistent with manufacturer specifications or good
engineering practices, and XII.H.5.d requires owners or operators to
retain records for a period of 5 years. Although there are requirements
to check for and document any problems observed while inspecting
condenser or air pollution control equipment, the State does not
require any corrective action be taken to fix the problem. The EPA
recommends the State add requirements for corrective action to be
taken. However, even as is, the provision strengthens the SIP, and
therefore the absence of a corrective action requirement within it does
not form a basis for disapproval.
v. Section XII.H.6
The reporting requirements included in section XII.H.6 support
additional enforcement and compliance efforts in connection with the
emission reduction requirements in XII.H.1. Under XII.H.6.a, owners or
operators submit to the Division on a semiannual basis a list of glycol
natural gas dehydrators subject to section XII.H, a list of condensers
or air pollution control equipment used to control emissions of VOCs,
and dates of inspections when condensers or air pollution control
equipment was found not to be operating properly. This provision
strengthens the SIP.
w. Section XII.I
Section XII.I is entirely new. It adds an exemption from the
otherwise applicable requirements of Section XII for an owner or
operator of any natural gas compressor station or natural gas drip
station, but only if the owner or operator applies control equipment
designed to achieve a VOC control efficiency of at least 95% to each
condensate storage tank or tank battery with uncontrolled VOC emissions
greater than or equal to two tons per year and meets certain other
requirements. This is more stringent than the system-wide requirement
because it requires 95% control at each tank or tank battery over the
threshold rather than a maximum of 90% control system-wide.
Recordkeeping and reporting requirements in XII.I.4 provide for
enforcement and compliance of emission reduction requirements in XII.I.
This provision strengthens the SIP.
Based on our analysis of Section XII changes, we find that
revisions are clerical in nature, do not change the substance of
currently approved SIP provisions, or are SIP strengthening provisions.
The State has not yet submitted a RACT analysis for this
[[Page 14825]]
source category. Colorado has until October 27, 2018, to submit SIP
revisions to address requirements of the EPA's oil and gas CTG
published in 2016 (see footnote 37 of this notice). We therefore we
propose approving the changes in Section XII.
(iv) Section XIII
Section XIII regulates VOC emissions from graphic arts and printing
processes.
a. Sections XIII.A
Changes to Section XIII.A are clerical in nature and do not affect
the substance of the requirements.
b. Section XIII.B
Section XIII.B addresses VOC emissions from the use of fountain
solutions, cleaning materials, and inks at lithographic and letterpress
printing operations. XIII.B.1 includes general provisions of the rule
including definitions, applicability, and work practice requirements,
and VOC content limits for inks. Section XIII.B.2 outlines requirements
for cleaning materials used at offset lithographic printing and
letterpress printing operations and exempted materials and operations.
Section XIII.B.3 contains requirements for the use of fountain
solutions at offset lithographic printing operations, sheet-fed
printing operations, and for non-heatset web printing. Section XIII.B.4
sets forth control requirements for heatset web offset lithographic and
heatset web letterpress printing operations. Requirements include
reducing VOC emissions from heatset dryers thorough an emission control
system with a control efficiency of 90% or greater and 95% or greater
for control devices installed on or after January 1, 2017. Section
XIII.B.4.d outlines exemptions from control requirements in Section
XIII.B.4. Finally, XIII.B.5 \51\ contains monitoring, recordkeeping,
and reporting requirements for compliance with VOC emission reduction
requirements in XIII.B.4. We find that the provisions are consistent
with CAA requirements and CTGs, and that they strengthen the SIP.
---------------------------------------------------------------------------
\51\ Section XIII.B.5. contains a numbering error. The State has
committed to correcting the errors in Section XIII.B.5.a. in a
subsequent SIP revision which are currently numbered
``XIII.E.5.a.,'' ``XIII.E.5.b.,'' and ``XIII.E.5.c.''
---------------------------------------------------------------------------
Therefore, we propose to approve the changes in Section XIII.
(v) Section XVI
Section XVI specifies emission control requirements for stationary
and portable engines and other combustion equipment.
a. Section XVI.A.-XVI.C
Revisions in Sections XVI.A through XVI.C make grammatical changes
and update references to section numbers. Colorado did not change the
substance of this provision.
b. Section XVI.D
Section XVI.D. adds a combustion adjustment requirement for
individual pieces of combustion equipment at major sources of
NOX in Section XVI.D. The requirements in Section XVI.D
apply to some equipment that is not subject to work practices under the
NESHAPs that have uncontrolled actual NOX emissions equal to
or greater than 5 tpy. Sections XVI.D.2.a-d include inspection and
adjustment requirements for boilers, process heaters, duct burners,
stationary combustion turbines, and stationary internal combustion
engines. Section XVI.D.2.e requires owners and operators to operate and
maintain equipment subject to Section XVI.D consistent with
manufacturer's specifications or good engineering and maintenance
practices. Section XVI.D.2.f outlines combustion adjustment frequency
requirements and Section XVI.D.3 includes recordkeeping requirements
for owners and operators when implementing combustion process
adjustments. Section XVI.D.4 sets forth alternative options to the
requirements in Sections XVI.D.2.a-e and XVI.D.3.a including conducting
combustion process adjustments according to manufacturer's recommended
procedures and schedules, or conducting tune-ups or adjustments
according to schedules and procedures of applicable NSPS or NESHAPs. We
find that the provisions in Section XVI.D are consistent with Clean Air
Act requirements and CTGs, and that they strengthen the SIP.
For the reasons previously explained, we propose to approve the
changes in Section XVI.
(vi) Section XIX
Section XIX establishes RACT requirements for emission points at
major sources of VOC and NOX in the DMNFR area. We will be
acting on Colorado's RACT demonstration for major sources and revisions
to Section XIX in a future rulemaking.
V. Proposed Action
We propose to approve the SIP submittal from the State of Colorado
for the DMNFR ozone nonattainment area submitted on May 31, 2017.
Specifically, we propose to approve the following:
Attainment demonstration with weight of evidence analysis
for the 2008 ozone NAAQS;
Base and future year emissions inventories;
RFP Demonstration;
Demonstration of RACT for VOC CTG sources (except for the
following CTG source categories as to which we are not taking any
action at this time: Metal Furniture Coatings, 2007; Miscellaneous
Metal Products Coatings, 2008; Wood Furniture Manufacturing Operations,
1996; Industrial Cleaning Solvents, 2006; Aerospace, 1997; and Oil and
Natural Gas Industry, 2016.);
Demonstration of RACM implementation;
Motor vehicle I/M program revisions in Colorado's Reg. No.
11;
NNSR program;
Contingency measures plan;
MVEBs; and
Revisions to Colorado's Reg. No. 7 (except for revisions
to Reg. No. 7, Section X pertaining to VOC controls of industrial
cleaning solvents and Reg. No. 7, Section XIX revisions pertaining to
RACT requirements for major sources as to which we are not taking any
action).
We also propose to approve SIP revisions to Reg. No. 7 submitted by
the State on May 13, 2013, except for provisions that have been
superseded by later submissions, as to which we are not taking any
action. We propose these actions in accordance with section 110 and
part D of the CAA.
VI. Incorporation by Reference
In this rule, the EPA is proposing to include in a final EPA rule
regulatory text that includes incorporation by reference. In accordance
with requirements of 1 CFR 51.5, the EPA is proposing to incorporate by
reference Colorado Regulation Number 11 pertaining to regulation of the
State's motor vehicle emissions inspection program and Colorado
Regulation Number 7 pertaining to regulation of sources of VOC and
NOX emissions discussed in section IV., J. Motor Vehicle
Inspection and Maintenance Program (I/M) Program and N. SIP Control
Measures of this preamble. The EPA has made, and will continue to make,
these materials generally available electronically through
www.regulations.gov and in hard copy at the appropriate EPA office
(please contact the person identified in the For Further Information
Contact section of this preamble for more information).
[[Page 14826]]
VII. 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 final 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).
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Carbon monoxide,
Incorporation by reference, Intergovernmental relations, Greenhouse
gases, Lead, Nitrogen dioxide, Ozone, Particulate matter, Reporting and
recordkeeping requirements, Sulfur oxides, Volatile organic compounds.
Authority: 42 U.S.C. 7401 et seq.
Dated: March 29, 2018
Douglas H. Benevento,
Regional Administrator, Region 8.
[FR Doc. 2018-06847 Filed 4-5-18; 8:45 am]
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