[Federal Register Volume 61, Number 236 (Friday, December 6, 1996)]
[Proposed Rules]
[Pages 64647-64651]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-31124]


=======================================================================
-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[FRL-5660-6]


Clean Air Act Approval and Promulgation of State Implementation 
Plan for Colorado; Oxygenated Gasoline Program; Carbon Monoxide State 
Implementation Plans for Denver and Longmont--Supplemental Notice; and 
PM10 State Implementation Plan for Denver--Supplemental Notice

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rulemaking.

-----------------------------------------------------------------------

SUMMARY: The Environmental Protection Agency (``EPA'' or the 
``Agency'') is proposing to approve a State Implementation Plan (SIP) 
revision submitted by the State of Colorado that would shorten the 
season for the oxygenated gasoline program from four to three and a 
half months. The State has requested that EPA approve Colorado's 
elimination of the requirement for oxygenated gasoline use during the 
last two weeks of February for the Denver-Boulder, Fort Collins-
Loveland, and Colorado Springs Metropolitan Statistical Areas (MSA). 
Based on Colorado's revision to its oxygenated gasoline requirements, 
EPA is reproposing approval of the Denver Carbon Monoxide (CO) SIP, 
Longmont CO SIP, and Denver PM10 SIP. EPA is taking the action to 
shorten the oxygenated gasoline season under Sections 110 and 211(m) of 
the Clean Air Act.

DATES: Comments must be received on or before January 6, 1997.

ADDRESSES: Comments may be mailed to Richard R. Long, Director, Air 
Programs, USEPA Region VIII (P2-A), 999 18th Street--Suite 500, Denver, 
Colorado 80202-2466. Copies of the documents relevant to this action 
are available for public inspection during normal business hours at the 
above address. Interested persons wanting to examine these documents 
should make an appointment with the appropriate contact person at least 
24 hours before the visiting day.

FOR FURTHER INFORMATION CONTACT: Scott Lee, at (303) 312-6736 or via e-
mail at [email protected]. While information may be requested 
via e-mail, comments must be submitted in writing to the EPA Region 
VIII address above.

SUPPLEMENTARY INFORMATION:

I. Background

    Section 211(m) of the Act requires that certain states submit 
revisions to their SIPs, and implement oxygenated gasoline programs, no 
later than November 1, 1992. This requirement applies to all states 
with carbon monoxide nonattainment areas with design values of 9.5 
parts per million or more based generally on 1988 and 1989 data. The 
Act requires that the winter oxygenated gasoline program apply to all 
gasoline sold in the larger of the Consolidated Metropolitan 
Statistical Area (CMSA) or Metropolitan Statistical Area (MSA) in which 
the nonattainment area is located. (In Colorado, these areas are the 
Colorado Springs MSA, Fort Collins-Loveland MSA, and the Denver-Boulder 
CMSA.) Gasoline for the specified control area(s) must contain not less 
than 2.7% oxygen by weight during that portion of the year in which the 
areas are prone to high ambient concentrations of carbon monoxide.
    Under Section 211(m)(2), the length of the control period, 
established by the EPA Administrator, shall not be less than four 
months unless a state can demonstrate that, because of meteorological 
conditions, a reduced control period will assure that there will be no 
carbon monoxide exceedances outside of such reduced period. EPA 
guidance \1\ identified an appropriate control period for Colorado, to 
run from the first day of November through the last day of February.
---------------------------------------------------------------------------

    \1\ See ``Guidelines for Oxygenated Gasoline Credit Programs and 
Guidelines on Establishment of Control Periods under Section 211(m) 
of the Clean Air Act as Amended--Notice of Availability,'' 57 FR 
47849 (October 20, 1992).
---------------------------------------------------------------------------

    On November 26, 1992, the State of Colorado submitted to EPA a 
revision to Regulation No. 13 (Colorado had an existing state oxygen 
gasoline program), which updated Colorado's oxygenated gasoline program 
to meet federal guidelines. The November 26, 1992 SIP revision provided 
for a 2.7% minimum oxygen content by weight program and established a 
control period in accordance with the EPA guidance. EPA proposed 
approval of this SIP revision on January 11, 1994 (59 FR 1513) and 
finalized approval on July 25, 1994 (59 FR 37698) in conjunction with a 
limited approval of Colorado's PM10 SIP.
    On July 11, 1994, Governor Roy Romer submitted comprehensive 
revisions to the Colorado SIP. Included in the comprehensive revision 
was a commitment to revise Regulation No. 13, Colorado Oxygenated 
Gasoline Program. The State's commitment, which it has since met, was 
to adopt and implement a 3.1% oxygenated fuels program, providing 
additional benefit over the 2.7% program already required in the area 
by Section 211(m) of the Act. The State determined it needed the 
additional benefit to ensure attainment of the CO standard in Denver by 
the applicable attainment date.
    The Colorado Air Quality Control Commission (AQCC) revised 
Regulation No. 13 in two steps. On July 19, 1994, the AQCC revised 
Regulation No. 13 to incorporate the ``maximum blending'' approach for 
the winter of 1994-95. This approach requires gasoline suppliers using 
methyl tertiary butyl ether (MTBE) as an oxygenate to blend at the 2.7% 
oxygen level (the maximum allowed by Federal regulations), and 
suppliers using ethanol as an oxygenate to blend at the 3.5% oxygen 
level (also the maximum allowed by Federal regulations). The market 
share of ethanol in the Denver area has exceeded 50% in recent years, 
and this approach is expected to result in at least a 3.1% oxygen 
content during each winter season. On October 20, 1994, the AQCC 
revised Regulation No. 13 to incorporate a more complex 3.1% 
``averaging'' program. If the maximum blending approach should fail to 
provide for at least a 3.1% oxygen content, the SIP revision provides 
that in subsequent winter seasons the averaging program will take 
effect. On September 29, 1995, the Governor submitted both revisions to 
EPA for approval. EPA found the submittal complete on November 30, 
1995. On July 9, 1996, EPA proposed approval of these revisions as a 
control measure for the Denver CO SIP and a

[[Page 64648]]

contingency measure for the Longmont CO SIP \2\ (61 FR 36004).
---------------------------------------------------------------------------

    \2\ For the Longmont CO SIP, the State also included the 
previously approved 2.7% oxygenated gasoline program as a control 
measure for the attainment demonstration. See 61 FR 36004.
---------------------------------------------------------------------------

    On October 19, 1995, the AQCC held a public hearing and adopted a 
SIP revision (revision to Regulation No. 13) based on the provision of 
section 211(m)(2) that allows EPA to reduce the oxygenated gasoline 
control period if the State can demonstrate that, because of 
meteorological conditions, a reduced period will assure that there will 
be no exceedances of the carbon monoxide standard outside of such 
reduced period. The revision eliminates the oxygenated gasoline program 
requirements for the last two weeks of February, otherwise leaving 
Colorado's program requirements unchanged. The Governor submitted the 
revision to EPA for approval on December 22, 1995 and indicated that 
the revision superseded and replaced all previous versions of 
Regulation No. 13.

II. EPA Analysis of State Submittal

    The applicable Clean Air Act requirements and EPA's rationale for 
its proposed actions are discussed below.

A. Section 211(m)(2) Demonstration

    Section 211(m)(2) of the Clean Air Act states the Administrator may 
reduce the oxygenated gasoline control period below the minimum four 
months ``if the State can demonstrate that because of meteorological 
conditions, a reduced period will assure that there will be no 
exceedances of the carbon monoxide standard outside of such reduced 
period.''
    Based on this provision, EPA required the State to demonstrate, 
based on worst-case meteorology for Denver for the last 21 years (as 
indicated by daily peak 8-hour CO concentrations), at least a 95% 
probability that there would be no exceedances of the CO standard 
during the last two weeks of February as a result of the shortening of 
the control period. EPA believes that to implement the statutory 
requirement of assuring no exceedances it is reasonable to require a 
State to show a very high probability of no exceedances and that 95% is 
a reasonable threshold for the State's demonstration here. Given the 
limitations of statistical analysis and the problems associated with 
proving a negative, EPA believes that a higher threshold would be 
inappropriate. EPA has not determined whether a lower threshold would 
provide sufficient assurance that there would be no exceedances.
    EPA believes the selected approach is conservative in assuring no 
exceedances of the CO standard. The risk analysis is based on worst-
case conditions, and assumes that no oxygenates are present in gasoline 
beginning on February 14. However, because 3.1% oxygen content 
requirements are enforced at both retail outlets and at the terminals 
that supply retail outlets until the end of the control period, 
oxygenated gasoline continues to be supplied to retail outlets from the 
terminals after the end of the control period. Historically, the 
presence of oxygenates has tapered off over a two week period after the 
control period ends. EPA expects this trend to continue. Therefore, 
some level of oxygenates will be in gasoline and CO reductions will 
continue to be realized throughout the two-week period for which 
control requirements are being eliminated.
    The State performed an analysis of the probability of a carbon 
monoxide exceedance in the Denver area during the last two weeks of 
February 1996 assuming no oxygenates in automotive fuels and all other 
elements of the Denver CO SIP in place. The analysis was based on a 
climatology of 21 years of measured daily peak carbon monoxide 
concentrations at the CAMP monitoring site in downtown Denver for the 
two weeks of interest. The high concentrations at the CAMP site have 
generally been the highest measured at CO monitoring sites in the 
Denver-Boulder area during the last two weeks of February. CAMP has 
also shown the greatest number of exceedances of the CO NAAQS during 
this two-week period. The twenty-one year period of record was 
sufficiently long to provide statistically realistic estimates of 
worst-case atmospheric dispersion conditions. Carbon monoxide emissions 
in Denver are expected to decrease between 1996 and 2005, and are 
expected to remain below 1996 levels at least through 2015, because a 
cleaner vehicle fleet is projected to more than offset the effect of 
increasing traffic volumes. Thus, the calculated probability of a CO 
NAAQS exceedance is at a maximum in 1996 at least through 2015. EPA 
does not believe it is necessary or reasonable to project beyond 2015 
to meet the statutory requirement of assuring no exceedances, given the 
increasing uncertainty inherent in such long-range forecasting, and 
believes that a shorter period might be adequate.
    In order to normalize the effects of emissions changes over the 21-
year study period, measured concentrations were adjusted to reflect 
estimated changes in CO emissions between the measurement year and 
1996. The resulting analysis provided a distribution of concentrations 
that would have occurred had the same historical meteorological 
conditions occurred at 1996 emission rates, without oxygenated fuels. 
The State's analysis, using three different statistical methods, showed 
that there would have been between a 3 and 5% probability of a CO NAAQS 
exceedance during the last two weeks of February 1996 if oxygenated 
fuels had not been in use. As noted above, due to the effects of fleet 
turnover, this 3 to 5% probability should represent the maximum 
probability of an exceedance during the last two weeks of February at 
least through 2015, and the probability should in fact decrease between 
1996 and 2005.
    For the Colorado Springs and Fort Collins-Loveland areas, if the 
oxygenated gasoline program is eliminated during the last two weeks of 
February, the probability of an exceedance during those two weeks is 
lower than it is for the Denver area. Compared to the Denver area, 
these areas have experienced significantly fewer exceedances of the CO 
standard and significantly lower ``high'' concentrations over the 
relevant time frame. Thus, the probability of an exceedance in the last 
two weeks of February 1996 in the Colorado Springs area and the Fort 
Collins-Loveland area, if the oxygenated gasoline program had been 
eliminated, would have been less than the 3 to 5% projected at the CAMP 
monitor. The probability is expected to decrease in years after 1996 
due to fleet turnover.
    The State's analysis meets the requirements discussed above and, 
thus, EPA can approve the shortening of the control period. However, if 
an exceedance occurs during the last two weeks of February, EPA intends 
to reevaluate this determination and consider calling for a SIP 
revision.

B. Impact on Denver and Longmont Carbon Monoxide SIPs

    On July 9, 1996, EPA proposed approval of the Denver and Longmont 
CO SIPs. Subsequent to this proposal, EPA became aware that the version 
of Regulation No. 13 that was a control measure for Denver and a 
contingency measure for Longmont had been replaced by the October 19, 
1995 version of Regulation No. 13. The two versions are identical 
except that the October 19, 1995 version eliminates the last two weeks 
of February from the program. In addition, for the Longmont CO SIP, the 
State took credit in the attainment demonstration for the 2.7% 
oxygenated gasoline program contained

[[Page 64649]]

in the version of Regulation No. 13 that EPA approved on July 25, 1994 
(59 FR 37698). The October 19, 1995 Regulation No. 13 replaces the four 
month, 2.7% program with the three-and-a-half month, 3.1% program. 
Hence, for purposes of the Denver and Longmont CO SIPs, EPA is 
publishing this supplemental notice to announce EPA's proposal to 
approve the SIPs with the October 19, 1995 version of Regulation No. 13 
substituted for the prior versions. The analysis regarding the CO SIPs 
remains as described in the July 9, 1996 proposal, except that EPA 
explains below the basis for its conclusion that the elimination of the 
last two weeks of the oxygenated gasoline program does not affect the 
validity of the attainment demonstration for the Denver CO SIP or the 
attainment demonstration and contingency measures for the Longmont CO 
SIP.
1. Denver CO SIP Attainment Demonstration
    The attainment demonstration is based on adverse meteorological 
conditions that occurred on January 15, 1988, and December 5, 1988. The 
State chose these dates because they represent the highest CO 
concentration episodes that were observed between January 1988 and 
January 1991.3 The attainment demonstration is based on the 
presumption that if the standard is attained under the conditions 
present during these highest ranking CO episodes, it will also be 
attained for the remainder of the winter season. This is consistent 
with EPA policy regarding CO attainment demonstrations. None of the top 
forty-eight ranked episodes during the 1988 to 1991 period occurred 
during the last two weeks of February. Concentrations during the 
highest-ranked late February episodes were much lower than those 
recorded during the highest episodes in December and January.4 The 
maximum calculated incremental increase (1.85 ppm) in CO concentration 
from non-oxygenated fuel vehicles would not be sufficient to increase 
total CO concentrations above 9.0 ppm during the last two weeks of 
February in the attainment year. Thus, NAAQS attainment would be 
assured during the last two weeks of February 2000 even without the 
oxygenated gasoline program.
---------------------------------------------------------------------------

    \3\ EPA guidance calls for the use of three years of monitoring 
data as the basis for modeling attainment. See ``Guideline for 
Regulatory Application of the Urban Airshed Model for Area-wide 
Carbon Monoxide,'' EPA-450/4-92-011a, June 1992.
    \4\ The highest value recorded in the 1988 to 1991 period was 
18.7 ppm. The 48th highest value during the 1988 to 1991 period was 
9.0 ppm. Since the highest-ranked episode during the last two weeks 
of February was not within the top 48 values overall, it was lower 
than 9.0 ppm and was much lower than 18.7 ppm.
---------------------------------------------------------------------------

2. Longmont CO SIP
    For the Longmont CO SIP, the State relied on the preexisting 2.7% 
oxygenated gasoline program as one of the control measures in the 
attainment demonstration and the State selected the 3.1% oxygenated 
gasoline program as the contingency measure. EPA believes neither 
measure is necessary for the last two weeks of February for the reasons 
discussed below.
    With respect to the attainment demonstration, the State calculated 
a second high value at the end of 1995 (the attainment date) of 6.97 
ppm CO. This second high value was calculated to occur on January 27, 
1995; high values for the last two weeks of February were even lower. 
However, even if one were to assume this second high value occurred 
during the last two weeks of February, the elimination of the 2.7% 
oxygenated fuels program would not have caused the second high value to 
exceed the CO standard. Since fleet turnover is expected to 
progressively reduce CO concentrations in future years, the elimination 
of the 2.7% oxygenated gasoline program during the last two weeks of 
February will also not affect maintenance of the CO standard in the 
Longmont area.
    With respect to the contingency measure, Longmont has never 
recorded an exceedance of the CO standard in February. The highest 
value recorded in February was 8.9 ppm, recorded on February 13, 1988, 
during the special monitoring study conducted in 1988 and 1989. The 
federal motor vehicle control program and the enhanced inspection/
maintenance program have led to significant reductions in emissions 
since that time, and these reductions are expected to continue in 
future years due to fleet turnover. Because Longmont has never had 
values over the CO standard during the last two weeks of February, and 
because data in recent years have not even approached the standard 
during the last two weeks in February, EPA has determined that it is 
not necessary for the State to require an oxygenated gasoline program 
during the last two weeks of February as a contingency measure in the 
Longmont CO SIP.

C. Impact on the Denver PM10 SIP

    On October 3, 1996, EPA proposed approval of the Denver PM10 
SIP. As with the Denver CO SIP, EPA became aware after proposing 
approval of the PM10 SIP that the version of Regulation No. 13 
that comprised a portion of the Denver PM10 SIP had been replaced 
by the October 19, 1995 version of Regulation No. 13. As noted above, 
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. Hence, 
for the purposes of the Denver PM10 SIP, EPA is publishing this 
supplemental notice to propose to approve the Denver PM10 SIP with 
the October 19, 1995 version of Regulation No. 13 substituted for the 
prior version. The analysis regarding the Denver PM10 SIP remains 
as described in the October 3, 1996 proposal, except that EPA explains 
below the basis for its conclusion that the elimination of the last two 
weeks of the oxygenated gasoline program does not affect the validity 
of the PM10 SIP.
    The modeling analysis for the PM10 SIP attainment 
demonstration used a gridded emissions inventory for the Denver 
Metropolitan area and five years of historical meteorological data from 
Stapleton airport. To ensure accuracy, the model was tested by 
comparing modeled PM10 concentrations with those actually measured 
at PM10 monitoring sites during the base years (1984-1989). Model 
evaluation testing showed that the PM10 modeling system met 
published EPA criteria for accuracy. In the PM10 SIP attainment 
demonstration runs, the emission inventory was projected to the year 
1995 and included emission reductions related to the proposed PM10 
control measures. Because five years of meteorological data were used, 
the 24-hour PM10 NAAQS is met when the predicted sixth highest 
PM10 concentration at all receptor locations is less than 150 
g/m3. The final SIP modeling results showed a sixth 
highest 1995 concentration of 147.8 g/m3 near the CAMP 
monitoring station in Downtown Denver.
    To estimate the effect of shortening the oxygenated fuels program 
on PM10 attainment, the effect on total motor vehicle emissions 
was first calculated. EPA estimated that motor vehicle exhaust 
emissions of PM10 during late February would increase by 
approximately 4.4% without oxygenated fuels. This emission increase was 
then factored back into the PM10 SIP attainment modeling to 
determine the effect on predicted concentrations. At the highest 
concentration receptor locations near the CAMP monitoring site, motor 
vehicle exhaust accounted for about 10.6 g/m3 of the 
total predicted PM10 concentrations. A 4.4% increase in motor 
vehicle exhaust would thus increase total PM10 concentrations by 
0.46 g/m3. At the CAMP receptor and

[[Page 64650]]

other locations nearby, this increase would have been insufficient to 
raise concentrations on the sixth highest ranked day above 150 
g/m3 for the attainment year. Readers should note that 
the shortening of the oxygenated gasoline program did not occur before 
the PM10 attainment date.
    EPA has also considered possible impacts on maintenance of the 
PM10 NAAQS through the milestone date of December 31, 1997 and has 
concluded that the elimination of the oxygenated gasoline program 
during the last two weeks of February will not affect the maintenance 
of the PM10 standard. In calculating the sixth highest PM10 
concentration in the maintenance year, the State estimated the growth 
in emissions and brought the concentration forward from the attainment 
demonstration. This led to a value of 149.9 g/m3. If 0.46 
g/m3 were added to this value, the 24-hour PM10 
standard would be exceeded. However, the sixth highest value occurred 
in December, not February, and thus, should be discarded. The seventh 
highest value also occurred in December and should also be discarded. 
However, even if this seventh highest value had occurred in the last 
two weeks of February, elimination of the oxygenated gasoline program 
would not have lead to an exceedance of the standard. The seventh 
highest value during the attainment year was 146.4 g/m3. 
Projecting to the end of 1997, this value would be 148.7 g/
m3. Adding 0.46 g/m3 to this value would not lead to 
an exceedance of the standard. The highest PM10 value actually 
modeled for the attainment year during the last two weeks of February 
was 140.1 g/m3, significantly lower than 146.4 
g/m3. Thus, the validity of the PM10 SIP is not 
affected by the elimination of the last two weeks of February from the 
oxygenated gasoline program.

III. Proposed Action

    EPA is proposing to approve revisions to the Colorado SIP submitted 
by the Governor on December 22, 1995. Specifically, EPA is proposing to 
approve revised Regulation No. 13, which was adopted by the Colorado 
Air Quality Control Commission on October 19, 1995. This revised 
Regulation No. 13 has the effect of eliminating the oxygenated gasoline 
requirements during the last two weeks of February for the Denver-
Boulder, Fort Collins-Loveland, and Colorado Springs Metropolitan 
Statistical Areas. In addition, EPA is proposing to approve this 
revision to Regulation No. 13 as a substitute for the October 20, 1994 
version of Regulation No. 13 that EPA proposed to approve as a control 
measure for the Denver CO SIP and a contingency measure for the 
Longmont CO SIP on July 9, 1996 (61 FR 36004), and as a substitute for 
the version of Regulation No. 13 that EPA approved on July 25, 1994 and 
that the State relied on as control measure in the Longmont CO SIP (see 
EPA's notice of proposed rulemaking dated July 9, 1996, 61 FR 36004) 
and the Denver PM10 SIP (see EPA's notice of proposed rulemaking 
dated October 3, 1996, 61 FR 51631, and EPA's limited approval of the 
PM10 SIP dated July 25, 1994, 59 FR 37698). Also, based on this 
revision to Regulation No. 13, EPA is reproposing to approve the 
attainment demonstration in the Denver CO SIP, the attainment 
demonstration in the Longmont CO SIP, and the attainment and 
maintenance demonstrations in the Denver PM10 SIP.
    EPA intends to take final action on this proposal to shorten the 
oxygenated gasoline season at the same time as it takes final action on 
the Denver and Longmont CO SIPs (proposed 61 FR 36004). EPA may take 
final action on the Denver PM10 SIP (proposed 61 FR 51631) at a 
separate time.

IV. Request for Public Comments

    EPA is requesting comments on today's proposal. As indicated at the 
outset of this document, EPA will consider any comments received by 
January 6, 1997. With respect to the Denver and Longmont CO SIPs and 
the Denver PM10 SIP, those wishing to comment should note that EPA is 
only entertaining comment regarding these SIPs on the change to 
Regulation No. 13 and any impact of this change on the approvability of 
these SIPs. The comment period regarding other aspects of the CO SIP 
has already closed and the comment period regarding other aspects of 
the PM10 SIP was specified at 61 FR 51631 and closes on December 2, 
1996.

V. Executive Order (EO) 12866

    Under EO 12866, 58 FR 51735 (October 4, 1993), EPA is required to 
determine whether regulatory actions are significant and therefore 
should be subject to OMB review, economic analysis, and the 
requirements of the EO. The EO defines a ``significant regulatory 
action'' as one that is likely to result in a rule that may meet at 
least one of the four criteria identified in section 3(f) of the EO, 
including, under paragraph (1), that the rule may ``have an annual 
effect on the economy of $100 million or more or adversely affect, in a 
material way, the economy, a sector of the economy, productivity, 
competition, jobs, the environment, public health or safety, or State, 
local, or tribal governments or communities.''
    The SIP-related actions proposed today have been classified as 
Table 3 actions 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. sec. 603 and 
604). Alternatively, EPA may certify 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 proposed 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. EPA, 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

[[Page 64651]]

informing and advising any small governments that may be significantly 
or uniquely impacted by the rule.
    EPA has determined that the SIP approval actions proposed today do 
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.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Carbon monoxide, 
Intergovernmental relations, Reporting and recordkeeping requirements.

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

    Dated: December 2, 1996.
Jack W. McGraw,
Acting Regional Administrator.
[FR Doc. 96-31124 Filed 12-5-96; 8:45 am]
BILLING CODE 6560-50-P