[Federal Register Volume 62, Number 74 (Thursday, April 17, 1997)]
[Rules and Regulations]
[Pages 18716-18723]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-9948]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[CO-001-0016; FRL-5802-6]


Clean Air Act Approval and Promulgation of PM10 
Implementation Plan for Denver, CO

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: EPA is approving the State Implementation Plan (SIP) revisions 
submitted by the Governor of Colorado for the purpose of bringing about 
the attainment of the national ambient air quality standards (NAAQS) 
for particulate matter with an aerodynamic diameter less than or equal 
to a nominal 10 micrometers (PM10) in the Denver area. The SIP 
revisions were submitted to satisfy certain Federal requirements for an 
approvable moderate nonattainment area PM10 SIP for Denver and, 
among other things, contain enforceable control measures. The bulk of 
the revisions were submitted on March 30, 1995. Revisions to Colorado 
Regulation No. 13 (oxygenated fuels), which is one of the control 
measures relied on in the SIP, were adopted by the Air Quality Control 
Commission

[[Page 18717]]

(AQCC) on October 19, 1995 and submitted to EPA on December 22, 1995. 
EPA proposed to approve the March 30, 1995 submission on October 3, 
1996. On December 6, 1996, EPA published a supplemental proposal to 
approve the Denver PM10 SIP based on the October 19, 1995 version 
of Regulation No. 13 rather than the prior version. This action 
supersedes EPA's July 25, 1994, final limited approval of certain 
control measures found in the State's June 7, 1993 Denver PM10 SIP 
submittal.

DATES This action will become effective on May 19, 1997.

ADDRESSES: Copies of the State's submittal and other information are 
available for inspection during normal business hours at the following 
locations: Environmental Protection Agency, Region VIII, Air Programs, 
999 18th Street, 3rd Floor, South Terrace, Denver, Colorado 80202-2466; 
Colorado Air Pollution Control Division, 4300 Cherry Creek Dr. South, 
Denver, Colorado 80222-1530; and the Air and Radiation Docket and 
Information Center, 401 M Street, SW, Washington, D.C. 20460.

FOR FURTHER INFORMATION CONTACT: Callie Videtich at (303) 312-6434.

SUPPLEMENTARY INFORMATION:

I. Background

    The Denver, Colorado area was designated nonattainment for 
PM10 and classified as moderate under sections 107(d)(4)(B) and 
188(a) of the Act, upon enactment of the Clean Air Act Amendments of 
1990.1 See 56 FR 56694 (Nov. 6, 1991) and 40 CFR 81.306 
(specifying PM10 nonattainment designation for the Denver 
metropolitan area). The air quality planning requirements for moderate 
PM10 nonattainment areas are set out in Part D, Subparts 1 and 4, 
of Title I of the Act. 2
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    \1\ The 1990 Amendments to the Clean Air Act made significant 
changes to the Act. See Pub. L. No. 101-549, 104 Stat. 2399. 
References herein are to the Clean Air Act, as amended (``the 
Act''). The Clean Air Act is codified, as amended, in the U.S. Code 
at 42 U.S.C. 7401, et seq.
    \2\ Subpart 1 contains provisions applicable to nonattainment 
areas generally and Subpart 4 contains provisions specifically 
applicable to PM10 nonattainment areas. At times, Subpart 1 and 
Subpart 4 overlap or conflict. EPA has attempted to clarify the 
relationship among these provisions in the ``General Preamble'' and, 
as appropriate, in today's notice and supporting information.
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    The EPA has issued a ``General Preamble'' describing EPA's 
preliminary views on how EPA intends to review SIPs and SIP revisions 
submitted under Title I of the Act, including those State submittals 
containing moderate PM10 nonattainment area SIP requirements (see 
generally 57 FR 13498 (April 16, 1992) and 57 FR 18070 (April 28, 
1992)). Because EPA is describing its interpretations here only in 
broad terms, the reader should refer to the General Preamble for a more 
detailed discussion of the interpretations of Title I advanced in this 
action and the supporting rationale. In this rulemaking action on the 
Colorado moderate PM10 SIP for the Denver nonattainment area, EPA 
is applying its interpretations considering the specific factual issues 
presented.
    Those States containing initial moderate PM10 nonattainment 
areas (those areas designated nonattainment under section 107(d)(4)(B) 
of the Act) were required to submit, among other things, the following 
plan provisions by November 15, 1991:
    1. Provisions to assure that reasonably available control measures 
(RACM) (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 (RACT)) shall be implemented no 
later than December 10, 1993;
    2. Either a demonstration (including air quality modeling) that the 
plan will provide for attainment as expeditiously as practicable but no 
later than December 31, 1994, or a demonstration that attainment by 
that date is impracticable;
    3. Quantitative milestones which are to be achieved every 3 years 
and which demonstrate reasonable further progress (RFP) toward 
attainment by December 31, 1994; and
    4. Provisions to assure that the control requirements applicable to 
major stationary sources of PM10 also apply to major stationary 
sources of PM10 precursors except where the Administrator 
determines that such sources do not contribute significantly to 
PM10 levels which exceed the NAAQS in the area. See sections 
172(c), 188, and 189 of the Act.
    Some provisions were due at a later date. States with initial 
moderate PM10 nonattainment areas were required to submit a new 
source review (NSR) permit program for the construction and operation 
of new and modified major stationary sources of PM10 by June 30, 
1992 (see section 189(a)). On January 14, 1993, the State submitted 
regulation revisions for the construction of new and modified major 
stationary sources. On August 18, 1994, EPA partially approved the 
State's NSR program for the Denver PM10 nonattainment area because 
the State had not yet submitted NSR provisions for sources of PM10 
precursors (i.e., NOX and SO2) in the Denver area (see 59 FR 
42300). On August 25, 1994, Colorado submitted additional NSR 
provisions for precursor emissions. EPA took final action on that SIP 
submittal on January 21, 1997 (62 FR 2910). Thus, the State has a 
fully-approved NSR permitting program in place for the Denver moderate 
PM10 nonattainment area.
    States were also required to submit contingency measures for 
PM10 moderate nonattainment areas by November 15, 1993. The 
contingency measures for the Denver PM10 nonattainment area were 
initially submitted by the Governor on December 9, 1993. However, those 
control measures were later incorporated into the revised March 30, 
1995 PM10 SIP to help demonstrate attainment and maintenance. 
Thus, the State developed new contingency measures, and on November 17, 
1995, the Governor submitted those measures to EPA. EPA took direct 
final rulemaking action on the contingency measures SIP submittal on 
September 23, 1996 (61 FR 49682). Because no adverse comments were 
received for the direct final rulemaking, the rule became effective on 
December 23, 1996.
    On June 7, 1993, the Governor submitted a SIP for Denver to EPA 
which was intended to satisfy those elements due November 15, 1991. On 
December 20, 1993, EPA proposed to conditionally approve that SIP and 
also proposed to approve the SIP's control measures for their limited 
purpose of strengthening the Colorado SIP (58 FR 66326). On July 25, 
1994, EPA granted limited approval of the control measures for the 
limited purpose of strengthening the SIP (59 FR 37698).
    During review of the technical information supporting the June 1993 
SIP, EPA examined information which raised concerns about the accuracy 
of the SIP's attainment demonstration. The SIP's technical support 
documentation suggested that the contribution from PM10 
``precursors'' (i.e., NOX and SO2) in the base year winter 
season may have been underestimated. Since the attainment demonstration 
provided with that SIP predicted a value of 149.9 g/m3 
over 24 hours, virtually any increase in precursor PM10 levels 
would result in predicted violations of the 24-hour standard.
    In the December 20, 1993, proposed rulemaking action, EPA requested 
public comment on its proposal to grant conditional approval of the SIP 
in light of the precursor issue. EPA reviewed the information submitted 
during the public comment period and concluded that precursors were 
underestimated by 5.4 g/m.\3\ Based upon this finding, EPA

[[Page 18718]]

delayed taking final action on the proposed conditional approval to 
allow the State an opportunity to develop additional controls to offset 
this increase. EPA never proceeded with the conditional approval. On 
March 30, 1995, the Governor submitted a SIP revision intended to 
provide controls to offset the increase in precursor emissions and 
provide credible attainment and maintenance demonstrations. Based on 
this SIP revision, EPA proposed approval of the PM10 SIP on 
October 3, 1996 (61 FR 51631).
    On July 18, 1995, and April 22, 1996, the Governor submitted 
additional revisions to the SIP which establish mobile source emissions 
budgets for PM10 and NOX. These budgets are used under EPA 
regulations for making transportation related conformity determinations 
as required by section 176(c) of the Act. EPA's transportation 
conformity rule provides that these budgets establish a cap on motor 
vehicle-related emissions which cannot be exceeded by the predicted 
transportation system emissions in the future unless the cap is amended 
by the State and approved by EPA as a SIP revision and attainment and 
maintenance of the standard can be demonstrated. EPA proposed approval 
of these emissions budgets on October 3, 1996 along with the Denver 
PM10 SIP. However, EPA is not taking final action on the two 
emissions budgets in order to more thoroughly consider comments 
received during the public comment period. These emissions budgets are 
not necessary to meet the Act's requirements for moderate PM10 
nonattainment areas and, therefore, will be addressed in a separate 
rulemaking.
    EPA became aware after proposing approval of the PM10 SIP that 
the version of Regulation No. 13 (oxygenated fuels) that was one of the 
control measures relied on in the Denver PM10 SIP had been 
replaced by the October 19, 1995 version of Regulation No. 13. The 
Governor submitted this version to EPA as a SIP revision on December 
22, 1995. The October 19, 1995 version eliminates the last two weeks 
from the program and calls for a 3.1% program rather than a 2.7% 
program. On December 6, 1996 (61 FR 64647) EPA published a supplemental 
document that, among other things, proposed to approve the Denver 
PM10 SIP with the October 19, 1995 version of Regulation No. 13 
substituted for the prior version. EPA received no comments regarding 
this aspect of the supplemental document and is proceeding with its 
approval of the Denver PM10 SIP based on the October 19, 1995 
version of Regulation No. 13.
    EPA has already approved the October 19, 1995 version of Regulation 
No. 13 as part of the Denver carbon monoxide (CO) SIP. The acting 
Regional Administrator for EPA Region VIII signed a Federal Register 
document approving the Denver CO SIP on January 31, 1997, but at the 
time this document was prepared, that approval had not yet been 
published in the Federal Register.

II. Response to Public Comments

    EPA received numerous comments on its proposed approval of the 
Denver PM10 SIP and the PM10 and NOX emissions budgets. 
In this document, EPA is addressing only those comments submitted on 
the Denver PM10 SIP. The comments received regarding the emissions 
budgets will be addressed in a later rulemaking action. The comments 
received on the Denver PM10 SIP and EPA's responses follow.
    1. The SIP revision fails to contain control measures to limit 
motor vehicle emissions from current vehicle miles traveled (VMT) or 
revised projections of VMT growth and does not provide for attainment.
    As EPA noted in its approval of the Denver CO SIP, the Denver 
Regional Council of Governments (DRCOG) produced revised estimates of 
daily vehicle miles traveled in the summer and fall of 1996. In early 
1996, DRCOG made some improvements to its transportation demand model 
(used for transportation planning, and to produce estimates of future 
VMT and speeds for air quality planning purposes) and validated the 
model with actual 1995 traffic counts recorded in Denver. These 
adjustments led to revised estimates of approximately 49 million miles 
per day of traffic in the Denver area (the previous modeled estimate 
had been approximately 45 million miles per day). The commentor 
referred to these revised estimates and suggested that EPA should 
disapprove the SIP on this basis, or conditionally approve the SIP and 
request that the State submit additional controls.
    EPA believes that the increases in VMT are not sufficient to 
warrant revisions to the PM10 SIP or its disapproval. EPA believes 
that it is reasonable to allow some margin of error for VMT projections 
in attainment demonstrations. This is because these projections are by 
their nature inexact. For CO SIPs, EPA has recognized this in the 
General Preamble and other guidance (see 57 FR 13532 and Section 187 
VMT Forecasting and Tracking Guidance, January 1992). EPA applied these 
policies in its approval of the Denver CO SIP and believes it is 
reasonable to extend them to the Denver PM10 SIP.
    It must be emphasized that only part of the estimated VMT increase 
is due to actual growth in traffic in the Denver region; the rest is 
due to use of improved methodologies for traffic counting in the 
region. For this reason, EPA believes it is more appropriate to 
consider the impact of actual growth in VMT by examining counts based 
on a consistent methodology, that is, the HPMS-based VMT Tracking 
Program. In November 1996, Colorado submitted its 1996 report of 1995 
actual annual VMT, as required by section 187 of the Act for CO SIPs. 
This report showed that actual 1995 VMT were 4.4% greater than the CO 
SIP projections and 1.3% greater than the most recent revised 
projection for 1995. These exceedances are within the allowable limits 
of EPA's VMT Tracking Program guidance for CO SIPs (5.0% and 3.0% for 
the respective VMT projections). EPA established these tolerances in 
recognition of the uncertainty inherent in attempting to measure actual 
VMT in a large urban area. Since the most recent reported actual annual 
VMT is within these allowable tolerances, EPA is not requiring the 
State to revise either the CO or PM10 SIPs.
    One other factor that should be noted is that virtually all of the 
growth in the metro area has occurred not in the downtown area, where 
the violations of the NAAQS have been monitored, but in outlying 
portions of the metro area. Thus, EPA would expect that VMT in the 
downtown area would increase at a lower rate than VMT for the metro 
area as a whole. This is supported by traffic counts at locations near 
downtown, which show that traffic in the central area increased at a 
rate of approximately 2-3% per year between 1990 and 1995, even though 
DRCOG estimates that traffic has increased approximately 4.5% per year 
region wide.
    2. Enforceability requirements of the Act are not satisfied for 
some control measures. EPA and the State lack enforcement authority for 
woodburning control measures relied on in the SIP.
    The commentor indicates that although the State's woodburning 
program requires that certification programs for new or replaced stoves 
be enforced through local building codes, there is no provision for 
enforcement by the State in the event the local government fails to 
adopt the certification requirement or fails to enforce the code. In 
fact, Regulation No. 4, Section II.A, prohibits the sale of wood stoves 
that do not meet the

[[Page 18719]]

emission standards of 40 CFR 60.532(b)(1) or (2). There is no exemption 
in the regulation for areas with local prohibitions. Thus, the State 
has the ability to directly enforce the certification program for 
woodburning stoves. And, because this provision will be part of the 
SIP, EPA and citizens will also be able to enforce it.
    For new and remodeled woodburning fireplaces, it is true that local 
building codes and ordinances serve as the primary mechanism for 
implementation and enforcement. However, Section VIII of Regulation No. 
4 requires the local jurisdictions to implement and enforce the local 
codes and ordinances. The State has the authority to enforce this 
requirement for implementation and enforcement. (See 25-7-115(l)(a), 
C.R.S.) Because this requirement is being approved by EPA, EPA and 
citizens will also have the ability to enforce it. Also, it appears 
that because these local codes and ordinances have been adopted as part 
of the SIP, the State may have the ability to enforce them directly 
pursuant to 25-7-128(l), C.R.S. EPA is approving them as part of the 
SIP, which will enable EPA and citizens to enforce them.
    For any local jurisdiction that has not adopted the relevant 
provisions for fireplaces into a building code or ordinance as of 
January 1, 1993, Section VII.A of Regulation No. 4 prohibits the 
installation of a fireplace unless it is of a type specified in Section 
VII.A. The State may enforce this requirement. Because EPA is approving 
this requirement, EPA and citizens will also have the ability to 
enforce it.
    3. VMT reduction measures are not adopted measures and are not 
enforceable.
    One commentor mentioned that several programs and projects 
administered by the Regional Transportation District (RTD) in Denver 
were included in the SIP modeling, but were not adopted as 
transportation control measures and/or made enforceable. These projects 
include RTD's MAC light rail line, bus service to Denver International 
Airport, and three discount/free bus pass programs. All of these 
programs have been implemented, and the SIP's assumption that these 
activities would continue to be implemented seems reasonable to EPA. 
The MAC light rail line is a vital transportation link to downtown and 
serves as the starting point for a second line proceeding down the 
southwest corridor, which has been approved and is under development, 
and a proposed third line in the southeast corridor, which is currently 
being evaluated as part of a Major Investment Study in that corridor. 
Bus service to the airport has been implemented, and there are no 
current plans to discontinue it. The discount bus pass programs 
mentioned in the SIP have proven quite popular, helping to ensure their 
continuation. It seems more reasonable for the SIP to assume that these 
RTD activities would continue than to assume they would be terminated.
    States are authorized to base SIP emission inventories on 
reasonable assumptions regarding the makeup of the transportation 
network in future years. Most of the inputs to the transportation 
modeling process represent informed assumptions, including the extent 
and location of population and employment, speeds, mode choice, and 
participation in trip-reduction activities. The impacts of these 
assumptions by their nature are impractical to make enforceable; there 
are no mechanisms through which the SIP can force population growth to 
occur in one area and not another, or can force citizens to participate 
in carpools or ride the bus. Likewise, assumptions about the future 
transportation network are reflected in the transportation data used to 
generate the inventory, but are not practical to make enforceable. Each 
transportation project in the transportation plan and Transportation 
Improvement Program (TIP) would have to be included in the SIP, and the 
SIP would have to be revised each time a new plan and TIP were 
generated. Also, many projects which do not reduce VMT still have a 
localized benefit for air quality such as the E470 beltway, which 
reduces CO in the central metro area. However, it would be 
inappropriate to include a VMT- and emissions-generating project like 
E470 in an SIP as a control measure.
    4. Modeling. One commentor criticized the accuracy of DRCOG's 
transportation modeling, and cited concerns from Environmental Defense 
Fund's Michael Replogle. The commentor did not supply a copy of Mr. 
Replogle's testimony and EPA does not have it in its possession. Thus, 
EPA has no basis to respond to specific concerns Mr. Replogle might 
have had. However, EPA believes the transportation modeling for the SIP 
was adequate and consistent with EPA guidance. EPA's guidance 
(Procedures for Preparing Emissions Projections, EPA-450/4-91-019, July 
1991) establishes minimum criteria for network modeling which DRCOG has 
met. In fact, DRCOG has exceeded guidance requirements, which would 
allow the use of less robust methods than network modeling. For 
example, the New York City CO SIP (which EPA has also approved) was not 
based on network modeling. EPA's guidance generally advises states to 
use the best tools they have available. Neither EPA's inventory nor SIP 
guidance is written in such a way as to advance the state of the art of 
VMT modeling in areas required to prepare SIPs or to require these 
areas to address every identifiable shortcoming with their particular 
modeling techniques. Regarding the commentor's assertions about VMT 
growth since the SIP was submitted, the reader should refer to EPA's 
response, above, regarding this issue.
    5. The regional network. One commentor stated that the DRCOG 
regional transportation network could not be properly used for SIP 
purposes because of inaccurate assumptions made within the modeling 
regarding whether certain projects would or would not be built.
    The commentor specifically noted that the construction of the final 
segment of E470 was not included in DRCOG's long-range transportation 
modeling, ostensibly because funding was not available for that 
project, while several light rail projects were included in the 
modeling even though funding for those projects is not certain. 
However, none of these projects were intended to be completed during 
the timeframe of the SIP's attainment and maintenance demonstrations 
(i.e., by the end of December 1998) and are not included in the SIP 
modeling. Thus, EPA's approval of the SIP is not affected in any way by 
the implementation or delay of these projects.
    The commentor also states that its ALTLOP--alternative list of 
projects--would have produced lesser growth in PM10 than DRCOG's 
list of projects. EPA notes that it cannot substitute its judgement for 
the State's or DRCOG's regarding which projects or controls to 
implement as long as the Act's requirements are met. The SIP 
demonstrates attainment and maintenance of the PM10 standard with 
the mix of projects selected by DRCOG.
    6. Monitoring and air sampling. A commentor indicated that further 
information would be forthcoming relating to continuity of monitoring, 
siting of monitors and whether tire wear particles are properly 
accounted for. EPA did not receive any further information on this 
subject and so has no basis upon which to respond. It should be noted 
that Colorado's State-wide SIP, which includes the Denver monitoring 
network, was reviewed and approved by EPA on September 23, 1993 (see 58 
FR 49434) as meeting the requirements of 40 CFR Parts 53 and 58, and 
the appendices to Part 50.

[[Page 18720]]

    7. Conformity. One commentor makes comments under this heading that 
go to the validity of the SIP. The commentor suggests that a value of 
149.9 g/m3 is too close to the NAAQS of 150 g/
m3 to be considered attainment, particularly when the projections 
used to effect this razor thin margin are acknowledged to have been 
``low''. Regarding the 149.9 g/m3 value, EPA regulations 
dictate that this value is considered attainment of the standard. See 
40 CFR 50.6 and Part 50, Appendix K. By ``projections'', EPA assumes 
the commentor is referring to the VMT projections relied on for the 
attainment and maintenance demonstrations. As explained in response to 
another comment, above, the difference between estimates of actual VMT 
and projections of VMT contained in the SIP falls within a reasonable 
margin of error and does not warrant a revision to or disapproval of 
the SIP. The reader should refer to the comment and response, above, 
for a more complete discussion of this issue.
    The last sentence of the commentor's comment appears to relate to 
the emissions budgets. EPA is not acting on the budgets in this action 
and will defer its response until it acts on the budgets.
    8. Other. One commentor endorsed EPA's proposed approval of the 
Denver element of the PM10 SIP, citing air quality monitoring data 
collected since 1992 that is below the current standard as evidence 
that the plan is working. This comment requires no response.

III. This Action

    EPA is approving the SIP revisions submitted by the Governor of 
Colorado for the purpose of bringing about the attainment of the NAAQS 
for PM10. The revisions were submitted to satisfy certain federal 
requirements for moderate PM10 nonattainment areas. The bulk of 
the revisions were adopted by the AQCC on October 20, 1994 with an 
amendment on December 15, 1994 and were submitted by the Governor on 
March 30, 1995. However, revisions to Regulation No. 13 (oxygenated 
fuels) were adopted by the AQCC on October 19, 1995 and submitted to 
EPA on December 22, 1995. EPA is basing its approval of the PM10 
SIP on this October 19, 1995 version of Regulation No. 13 rather than 
the version relied on in the March 30, 1995 submission. Also, the State 
submitted a number of technical support documents to EPA after the 
original June 7, 1993 PM10 SIP submittal that explain or are 
relied on by the March 30, 1995 submittal and comprise part of the 
basis for EPA's approval. These documents were submitted on June 8, 
1993, June 10, 1993, June 25, 1993, July 19, 1993, August 5, 1993, 
September 3, 1993, September 21, 1993, October 20, 1993, December 12, 
1993, January 19, 1994, December 23, 1994, March 3, 1995, and November 
8, 1995.
    It should be noted that the March 30, 1995 submission, in addition 
to including new control measures, also relies on control measures to 
which EPA granted limited approval on July 25, 1994 (59 FR 37698). The 
current action granting full approval to the PM10 SIP supersedes 
EPA's limited approval. To avoid confusion, EPA is referencing in the 
regulatory materials that are part of this document both new provisions 
and provisions to which EPA gave limited approval in its July 25, 1994 
action. These later provisions include portions of Regulation No. 1 and 
Regulation No. 4 that, through administrative error, EPA inadvertently 
failed to reference in the incorporation by reference section of the 
July 1994 action. To correct this clerical error, EPA is now 
incorporating all of Regulation No. 4, and all of Regulation No. 1 
except Section V. As noted in EPA's action of December 3, 1986 (51 FR 
43610), the sources subject to Section V of Regulation No. 1 are no 
longer operating, and thus, there is no reason to act on Section V.
    EPA is approving the control strategies that are relied upon in the 
March 30, 1995 submission as well as the attainment and maintenance 
demonstrations contained therein. EPA views the following measures as 
reasonable, enforceable, and responsible for PM10 emissions 
reductions in the Denver PM10 nonattainment area: (1) Colorado 
Regulation No. 4 which regulates residential wood burning; (2) local 
woodburning ordinances and resolutions; (3) Colorado Regulation No. 16 
which establishes street sanding and sweeping requirements; (4) the 
federal tailpipe standards, which provide an ongoing benefit due to 
fleet turnover, and Colorado Regulations 11, 12, and 13 which were 
developed by the State and approved by EPA independently from the 
PM10 SIP but are included because of their particulate emission 
reduction benefit; (5) Colorado Regulation No. 1, which provides 
stationary source emission control regulations for particulates, 
smokes, carbon monoxide and sulfur oxides 3; and (6) individual 
stationary source permit revisions for Public Service Company Cherokee 
facility, Purina Mills, Electron Corporation, TRIGEN--Colorado Energy 
Corporation 4, Rocky Mountain Bottle Company, Conoco Refinery, and 
Adolph Coors Brewery. The State's submission demonstrates attainment of 
the PM10 NAAQS by December 31, 1994, with continued maintenance of 
the standard through December 31, 1997.
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    \3\ Carbon monoxide is not relevant to the PM10 SIP. 
However, EPA is incorporating by reference Section IX of Regulation 
No. 1 that relates to CO to accurately reflect the reorganization of 
the regulation.
    \4\ Permit changes for TRIGEN achieve PM10 SIP precursor 
emission reductions to accommodate precursor emission increases at 
the Rocky Mountain Bottle facility (formerly the Coors Glass Plant). 
While these revisions to the emissions limits are acceptable for 
meeting RACM/RACT requirements, EPA's action herein regarding these 
limits does not in any manner relieve these companies of the 
obligation to comply with any nonattainment NSR permitting 
requirements that might apply to such changes in emissions limits.
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    A more detailed discussion of the individual source contributions 
and their associated control measures (including available control 
technology) can be found in the Technical Support Document accompanying 
EPA's October 3, 1996 proposed approval of the Denver moderate 
PM10 nonattainment area SIP (61 FR 51631). As noted elsewhere in 
this action, EPA received comments on the proposed action to approve 
the Denver PM10 SIP. EPA believes that the responses set forth in 
this action adequately address the comments and is proceeding with the 
approval as proposed.
    EPA has reviewed this request for revision of the federally-
approved SIP for conformance with the provisions of the Act. EPA has 
determined that this action conforms to those requirements.
    Nothing in this action should be construed as permitting or 
allowing or establishing a precedent for any future request for 
revision to any SIP. Each request for revision to any SIP shall be 
considered separately in light of specific technical, economic, and 
environmental factors and in relation to relevant statutory and 
regulatory requirements.

IV. Executive Order (EO) 12866

    This action has been classified as a Table 3 action for signature 
by the Regional Administrator under the procedures published in the 
Federal Register on January 19, 1989 (54 FR 2214-2225), as revised by a 
July 10, 1995 memorandum from Mary Nichols, Assistant Administrator for 
Air and Radiation. The Office of Management and Budget has exempted 
these regulatory actions from EO 12866 review.

V. Regulatory Flexibility

    Under the Regulatory Flexibility Act, 5 U.S.C. 600 et. seq., EPA 
must prepare a regulatory flexibility analysis assessing the impact of 
any proposed or final rule on small entities (5 U.S.C. 603 and 604). 
Alternatively, EPA may certify

[[Page 18721]]

that the rule will not have a significant impact on a substantial 
number of small entities. Small entities include small businesses, 
small not-for-profit enterprises, and government entities with 
jurisdiction over populations that are less than 50,000.
    SIP revision approvals under section 110 and subchapter I, Part D, 
of the CAA do not create any new requirements, but simply approve 
requirements that the State is already imposing. Therefore, because the 
Federal SIP approval process does not impose any new requirements, EPA 
certifies that this final rule would not have a significant impact on 
any small entities affected. Moreover, due to the nature of the 
Federal-State relationship under the CAA, preparation of a regulatory 
flexibility analysis would constitute Federal inquiry into the economic 
reasonableness of State actions. The CAA forbids EPA to base its 
actions concerning SIPs on such grounds. Union Electric Co. v. 
U.S.E.P.A., 427 U.S. 246, 256-266 (S. Ct. 1976); 42 U.S.C. section 
7410(a)(2).

VI. Unfunded Mandates

    Under section 202 of the Unfunded Mandates Reform Act of 1995 
(``Unfunded Mandates Act''), signed into law on March 22, 1995, EPA 
must prepare a budgetary impact statement to accompany any proposed or 
final rule that includes a Federal mandate that may result in estimated 
costs to State, local, or tribal governments in the aggregate, or to 
the private sector, of $100 million or more. Under section 205, EPA 
must select the most cost-effective and least burdensome alternative 
that achieves the objectives of the rule and is consistent with 
statutory requirements. Section 203 requires EPA to establish a plan 
for informing and advising any small governments that may be 
significantly or uniquely impacted by the rule.
    EPA has determined that today's final approval action does not 
include a Federal mandate that may result in estimated costs of $100 
million or more to either State, local or tribal governments in the 
aggregate, or to the private sector. These Federal actions approve pre-
existing requirements under State or local law, and impose no new 
requirements. Accordingly, no additional costs to State, local or 
tribal governments, or to the private sector, result from these 
actions.

VII. Submission to Congress and the General Accounting Office

    Under 5 U.S.C. 801(a)(1)(A) as added by the Small Business 
Regulatory Enforcement Fairness Act of 1996, EPA submitted a report 
containing this rule and other required information to the U.S. Senate, 
the U.S. House of Representatives and the Comptroller of the General 
Accounting Office prior to publication of the rule in today's Federal 
Register. This rule is not a ``major rule'' as defined by 5 U.S.C. 
804(2).

VIII. Petitions for Judicial Review

    Under section 307(b)(1) of the Act, petitions for judicial review 
of this action must be filed in the United States Court of Appeals for 
the appropriate circuit by June 16, 1997. Filing a petition for 
reconsideration by the Administrator of this final rule does not affect 
the finality of this rule for the purposes of judicial review nor does 
it extend the time within which a petition for judicial review may be 
filed, and shall not postpone the effectiveness of such rule or action. 
This action may not be challenged later in proceedings to enforce its 
requirements (see section 307(b)(2)).

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Hydrocarbons, 
Incorporation by reference, Intergovernmental relations, Nitrogen 
dioxide, Particulate matter, Reporting and record keeping requirements, 
Sulfur dioxide, and Volatile organic compounds.

    Dated: February 28, 1997.
Jack W. McGraw,
Acting Regional Administrator.

    Part 52, chapter I, title 40 of the Code of Federal Regulations is 
amended as follows:

PART 52--[AMENDED]

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

    Authority: 42 U.S.C. 7401-7671q.

Subpart G--Colorado

    2. Section 52.320 is amended by adding paragraph (c)(82) to read as 
follows:


Sec. 52.320  Identification of plan.

* * * * *
    (c) * * *
    (82) The Governor of Colorado submitted the Denver moderate 
nonattainment area PM10 State Implementation Plan (SIP) with a 
letter dated March 30, 1995. The Governor submitted revisions to 
Regulation No. 13, one of the control measures relied on in the 
PM10 SIP, on December 22, 1995. These submittals as well as 
support documentation submittals made on June 8, 1993, June 10, 1993, 
June 25, 1993, July 19, 1993, August 5, 1993, September 3, 1993, 
September 21, 1993, October 20, 1993, December 12, 1993, January 19, 
1994, December 23, 1994, March 3, 1995, and November 8, 1995 satisfy 
those moderate PM10 nonattainment area SIP requirements due for 
the Denver PM10 nonattainment area on November 15, 1991. EPA is 
approving the SIP. This approval replaces the previous limited approval 
at 40 CFR 52.320(c)(61).
    (i) Incorporation by reference.
    (A) Regulation No. 4, ``Regulation on the Sale of New Woodstoves 
and the Use of Certain Woodburning Appliances During High Pollution 
Days,'' 5 CCR 1001-6, as adopted by the Air Quality Control Commission 
on June 24, 1993, effective August 30, 1993.
    (B) Local woodburning ordinances and resolutions.
    (1) Arvada, Colorado. Ordinance number 2451, effective November 2, 
1987, regarding woodburning restrictions.
    (2) Aurora, Colorado. Ordinance numbers 87-118 and 92-14, effective 
May 22, 1987 and May 22, 1992, respectively, regarding woodburning 
restrictions.
    (3) Boulder, Colorado. Ordinance numbers 5007 and 5445, adopted 
November 25, 1986 and April 21, 1992, respectively, regarding 
woodburning restrictions.
    (4) Broomfield, Colorado. Ordinance number 794, effective November 
24, 1988, regarding woodburning restrictions.
    (5) Denver, Colorado. Ordinance numbers 293 and 1018, approved May 
30, 1990 and December 16, 1993, respectively, regarding woodburning 
restrictions.
    (6) Douglas County, Colorado. Resolution number 991-128, adopted 
November 14, 1991, regarding woodburning restrictions.
    (7) Englewood, Colorado. Ordinance numbers 31 and 39, passed on 
July 20, 1992, regarding woodburning restrictions.
    (8) Federal Heights, Colorado. Ordinance number 565, adopted 
January 5, 1988, regarding woodburning restrictions.
    (9) Glendale, Colorado. Ordinance numbers 2 and 14, adopted January 
5, 1988 and effective on October 20, 1992, respectively, regarding 
woodburning restrictions.
    (10) Greenwood Village, Colorado. Ordinance numbers 17 and 9, 
effective July 9, 1988 and March 25, 1992, respectively, regarding 
woodburning restrictions.

[[Page 18722]]

    (11) Jefferson County, Colorado. Resolution numbers CC89-873 and 
CC90-617, dated December 29, 1989 and August 7, 1990, respectively, 
regarding woodburning restrictions.
    (12) Lafayette, Colorado. Ordinance number 24; series 1988, 
effective November 15, 1988, regarding woodburning prohibitions.
    (13) Lakewood, Colorado. Ordinance numbers 0-86-113 and 0-92-61, 
effective December 1, 1986 and November 28, 1992, respectively, 
regarding woodburning restrictions.
    (14) Littleton, Colorado. Ordinance numbers 51 and 26, passed on 
December 6, 1988 and August 18, 1992, respectively, regarding 
woodburning restrictions.
    (15) Longmont, Colorado. Ordinance number 0-89-1, adopted December 
27, 1988, regarding woodburning restrictions.
    (16) Mountain View, Colorado. Ordinance number 90-5, approved on 
January 7, 1991, regarding woodburning restrictions.
    (17) Sheridan, Colorado. Ordinance numbers 22 and 1, approved 
October 25, 1988 and February 9, 1993, respectively, regarding 
woodburning restrictions.
    (18) Thornton, Colorado. Ordinance numbers 2120 and 2194, adopted 
October 28, 1991 and September 28, 1992, respectively, regarding 
woodburning restrictions.
    (19) Westminster, Colorado. Ordinance numbers 1742 and 2092, 
enacted on November 9, 1987 and December 28, 1992, respectively, 
regarding woodburning restrictions.
    (C) Regulation No. 16, ``Concerning Material Specifications for, 
Use of, and Clean-up of Street Sanding Material,'' 5 CCR 1001-18, as 
adopted by the Air Quality Control Commission on September 22, 1994, 
effective November 30, 1994.
    (D) Regulation No. 1, ``Emission Control Regulations for 
Particulates, Smokes, Carbon Monoxide, and Sulfur Oxides for the State 
of Colorado,'' 5 CCR 1001-3, Sections I-IV and VI-IX, and Appendices A 
and B, as adopted by the Air Quality Control Commission on August 19, 
1993, effective October 20, 1993; with revisions to Sections VII and 
VIII, adopted by the Air Quality Control Commission on September 22, 
1994, effective November 30, 1994.
    (E) Public Service Company Cherokee facility SO2 emission 
limitations for the power facility.
    (1) Permit 86AD352(1), effective date November 13, 1986, regulates 
SO2 emissions at Unit #1.
    (2) Permit 86AD352-2, effective date April 30, 1992, regulates 
SO2 emissions at Unit #4.
    (F) Purina Mills Inc. total PM10 emissions limitations at the 
animal feed manufacturing facility.
    (1) Permit 93AD1008-1, effective date October 19, 1993, regulating 
emissions at the finished product loadout facility.
    (2) Permit 93AD1008-2, effective date October 19, 1993, regulating 
emissions at the grain receiving facility.
    (G) Electron Corporation total PM10 emission limitations at 
the gray iron foundry.
    (1) Permit 93AR1363-1, effective date January 12, 1994, regulating 
emissions at the Table shot blaster and associated baghouse.
    (2) Permit 93AR1363-2, effective date January 12, 1994, regulating 
emissions at the five grinding booths-stand and associated baghouse.
    (3) Permit 93AR1363-3, effective date January 12, 1994, regulating 
emissions at the five grinding booths-hand and associated baghouse.
    (4) Permit 93AR1363-4, effective date January 12, 1994, regulating 
emissions at the Muller-25 sand system and associated baghouse.
    (5) Permit 93AR1363-5, effective date January 12, 1994, regulating 
emissions at the Coleman core oven-sand.
    (6) Permit 93AR1363-6, effective date January 12, 1994, regulating 
emissions at the Spinner wheelabrator and associated baghouse.
    (7) Permit 93AR1363-7, effective date January 12, 1994, regulating 
emissions at the Sand sile-core room and associated baghouse.
    (8) Permit 93AR1363-8, effective date January 12, 1994, regulating 
emissions from pouring of molten iron (casting) and castings cooling.
    (9) Permit 93AR1363-9 effective date January 12, 1994, regulating 
emissions at three tumble blast machines and associated baghouse.
    (10) Permit 93AR1363-10, effective date January 12, 1994, 
regulating emissions at two mullers-80A and associated baghouse.
    (11) Permit 93AR1363-11, effective date January 12, 1994, 
regulating emissions at the Casting shakeout hood and associated 
baghouse.
    (12) Permit 93AR1363-12, effective date January 12, 1994, 
regulating emissions at the Casting-disamatic mold and associated 
baghouse.
    (13) Permit 93AR1363-13, effective date January 12, 1994, 
regulating emissions at the Sand silo-disamatic and associated 
baghouse.
    (14) Permit 93AR1363-14, effective date January 12, 1994, 
regulating emissions at the Sand silo-air set room and associated 
baghouse.
    (15) Permit 93AR1363-15, effective date January 12, 1994, 
regulating emissions at two electric induction furnaces and associated 
baghouse.
    (16) Permit 93AR1363-16, effective date January 12, 1994, 
regulating emissions at two Inducto-Therm electric induction furnaces 
model #2000/4, serial nos. 40102 and 40103, and associated baghouse.
    (17) Permit 93AR1363-17, effective date January 12, 1994, 
regulating emissions from chemicals used in core making process.
    (18) Permit 93AR1363-18, effective date January 12, 1994, 
regulating emissions at the Loop shakeout and associated baghouse.
    (19) Permit 93AR1363-19, effective date January 12, 1994, 
regulating emissions at the Floor shakeout and associated baghouse.
    (20) Permit 93AR1363-20, effective date January 12, 1994, 
regulating emissions at the Reclaim sand and associated baghouse.
    (21) Permit 93AR1363-21 effective date January 12, 1994, regulating 
emissions at the Sand heater/cooler and associated baghouse.
    (22) Permit 93AR1363-22, effective date January 12, 1994, 
regulating emissions at the Paint spray booth.
    (H) TRIGEN-Colorado Energy Corporation permit emissions limitations 
at two boilers.
    (1) Permit 10JE660, effective date February 25, 1997, regulating 
emissions at the #4 boiler: tangential fired cogeneration steam boiler.
    (2) Permit 11JE305-1, effective date February 19, 1997, regulating 
emissions at the #5 boiler: tangential fired cogeneration steam boiler.
    (I) Rocky Mountain Bottle Company emission limitations on three 
furnaces.
    (1) Permit 92JE129-1, effective date June 29, 1995, regulating 
emissions at the KTG glass melting furnaces #1, #2 and #3.
    (J) Conoco Refinery allowable emission limitations from the 
refinery.
    (1) Permit 90AD524, effective date March 20, 1991, regulating a 
Tulsa natural gas fired 20MMbtu/hour heater equipped with low-NOX 
burners.
    (2) Permit 90AD053, effective date March 20, 1991, regulating 
process heaters H-10, H-11 and H-27 and process boilers B4, B6, and B8 
all burning fuel gas only.
    (3) Permit 91AD180-3, effective December 28, 1992, regulating the 
three stage Claus sulfur recovery unit with tail gas recovery unit.
    (ii) Additional material.
    (A) Regional Air Quality Council, ``Guidelines for Reducing Air 
Pollution from Street Sanding'' sets voluntary guidelines for public 
works departments to follow to reduce the amount of street

[[Page 18723]]

sand applied, and includes recommendations for increasing the 
effectiveness of street cleaning operations.
    3. Section 52.332 is amended by adding paragraph (f) to read as 
follows:


Sec. 52.332  Moderate PM10 Nonattainment Area Plans.

* * * * *
    (f) On March 30, 1995, and November 17, 1995, the Governor of 
Colorado submitted the moderate PM10 nonattainment area plan for 
the Denver area. The March 30, 1995 submittal was made to satisfy those 
moderate PM10 nonattainment area SIP requirements due for the 
Denver PM10 nonattainment area on November 15, 1991. The November 
17, 1995 submittal was also made to satisfy the PM10 contingency 
measure requirements which were due for Denver on November 15, 1993.

[FR Doc. 97-9948 Filed 4-16-97; 8:45 am]
BILLING CODE 6560-50-P