[Federal Register Volume 61, Number 156 (Monday, August 12, 1996)]
[Proposed Rules]
[Pages 41759-41764]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-20370]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 81

[NV-029-0001; FRL-5549-5]


Clean Air Act Reclassification; Nevada-Clark County Nonattainment 
Area; Carbon Monoxide

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA proposes to find that the Clark County, Nevada carbon 
monoxide (CO) nonattainment area has met the criteria in section 
186(b)(4) of the Clean Air Act (CAA): it exceeded the CO National 
Ambient Air Quality Standard (NAAQS) once in 1995; it has adopted and 
implemented the CAA required moderate nonattainment area control 
measures; and, it has demonstrated progress towards attaining the CO 
NAAQS. As a result of this finding, EPA proposes to grant a one-year 
extension of Clark County's moderate area attainment date from December 
31, 1995 to December 31, 1996. EPA's proposed finding is based on a 
review of monitored air quality data for compliance with the CO NAAQS, 
as well as the air quality planning progress of Clark County. If EPA 
takes final action on this proposed finding, the Clark County CO 
nonattainment area will remain classified as a moderate CO 
nonattainment area as a result of extending the CAA mandated attainment 
date for one year. The intended effect of extending the attainment date 
is to allow Nevada and Clark County either to fully implement and 
strengthen current CO control measures, or to adopt additional control 
measures prior to the 1996-97 winter CO season in an effort to attain 
the CO NAAQS.

DATES: Written comments on this proposal must be received by September 
11, 1996.

ADDRESSES: Written comments should be sent to:
Wallace Woo, Chief, Plans Development Section, A-2-2, U.S. 
Environmental Protection Agency, Region 9, 75 Hawthorne Street, San 
Francisco, California 94105.
    The rulemaking docket for this proposal, Docket No. 96-NV-PL-001, 
may be inspected and copied at the following location between 8 a.m. 
and 4:30 p.m. on weekdays. A reasonable fee may be charged for copying 
parts of the docket.
U.S. Environmental Protection Agency, Region 9, Air and Toxics 
Division, Plans Development Section, A-2-2, 75 Hawthorne Street, San 
Francisco, California 94105.
    Copies of the docket are also available at the State and local 
offices listed below:
Nevada Division of Environmental Protection, 333 West Nye Lane, Carson 
City, Nevada, 89710; and,
Clark County Department of Comprehensive Planning, 500 South Grand 
Central Parkway, Suite 3012, Las Vegas, Nevada, 89155-1741.
FOR FURTHER INFORMATION CONTACT: Jerry Wamsley, A-2-2, Air and Toxics 
Division, U.S. Environmental Protection Agency, Region 9, 75 Hawthorne 
Street, San Francisco, California 94105, (415) 744-1226.
SUPPLEMENTARY INFORMATION:

I. Background

A. CAA Requirements and EPA Actions Concerning Designation and 
Classifications

    With enactment of the Clean Air Act Amendments of 1990, under 
section 107(d)(1)(C) of the Clean Air Act (CAA), each carbon monoxide 
(CO) area designated nonattainment prior to enactment of the 1990 
Amendments was designated nonattainment by operation of law. Under 
section 186(a) of the CAA, each CO area designated nonattainment under 
section 107(d) was also classified by operation of law as either 
``moderate'' or ``serious'' depending on the severity of the area's air 
quality problem. CO areas with design values between 9.1 and 16.4 parts 
per million (ppm) were classified as moderate. States containing areas 
that were classified as moderate nonattainment by

[[Page 41760]]

operation of law under section 107(d) were required to submit State 
implementation plans (SIPs) designed to attain the CO national ambient 
air quality standard (NAAQS) as expeditiously as practicable but no 
later than December 31, 1995.
    On November 6, 1991, Clark County was designated nonattainment for 
CO and was classified as a ``high'' moderate area given its design 
value of 14.4 ppm (See 56 FR 56694). Clark County's nonattainment 
designation and classification is codified at 40 CFR part 81.329. The 
moderate area SIP requirements are set forth in section 187(a) of the 
CAA and differ depending on whether the area's design value is below or 
above 12.7 parts per million (ppm). With its design value of 14.4 ppm, 
Clark County is required to meet the ``high'' moderate nonattainment 
area requirements and attain the CO NAAQS by December 31, 1995.

B. Reclassification to a Serious Nonattainment Area

    EPA has the responsibility, pursuant to sections 179(c) and 
186(b)(2) of the CAA, of determining within six months of the 
applicable attainment date, December 31, 1995, whether a moderate area 
has attained the CO NAAQS. Under section 186(b)(2)(A), if EPA finds 
that a moderate area has not attained the CO NAAQS, it is reclassified 
as serious by operation of law. Pursuant to section 186(b)(2)(B) of the 
Act, EPA must publish a notice in the Federal Register identifying 
areas which failed to attain the standard and therefore must be 
reclassified as serious by operation of law.
    EPA makes attainment determinations for CO nonattainment areas 
based upon whether an area has two years (or eight consecutive 
quarters) of clean air quality data.1 Section 179(c)(1) of the Act 
states that the attainment determination must be based upon an area's 
``air quality as of the attainment date.'' Consequently, EPA will 
determine whether an area's air quality has met the CO NAAQS by 
December 31, 1995 based upon the most recent two years of air quality 
data entered into the Aerometric Information Retrieval System (AIRS) 
data base.
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    \1\ See memorandum from Sally L. Shaver, Director, Air Quality 
Strategies and Standards Division, EPA, to Regional Air Office 
Directors, entitled ``Criteria for Granting Attainment Date 
Extensions, Making Attainment Determinations, and Determinations of 
Failure to Attain the NAAQS for Moderate CO Nonattainment Areas,'' 
October 23, 1995 (Shaver memorandum).
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    EPA determines a CO nonattainment area's air quality status in 
accordance with 40 CFR 50.8 and EPA policy.2 EPA has promulgated 
two NAAQS for CO: an eight-hour average concentration and a one-hour 
average concentration. Because there were no violations of the one-hour 
standard in the Clark County area in 1994 and 1995, this notice 
addresses only the air quality status of the Clark County area with 
respect to the eight-hour standard. The eight-hour CO NAAQS requires 
that not more than one non-overlapping eight-hour average per year per 
monitoring site can exceed 9.0 ppm (values below 9.5 are rounded down 
to 9.0 and they are not considered exceedances). The second exceedance 
of the eight-hour CO NAAQS at a given monitoring site within the same 
year constitutes a violation of the CO NAAQS.
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    \2\ See memorandum from William G. Laxton, Director, Technical 
Support Division, entitled ``Ozone and Carbon Monoxide Design Value 
Calculations'', June 18, 1990. See also Shaver memorandum.
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C. Attainment Date Extensions

    If a state does not have the two consecutive years of clean data 
necessary to show attainment of the NAAQS, it may apply, under section 
186(a)(4) of the CAA, for a one year attainment date extension. At its 
discretion, EPA may grant an extension if the area has: (1) measured no 
more than one exceedance of the CO NAAQS at any monitoring site in the 
nonattainment area in the year preceding the extension year, and (2) 
complied with the requirements and commitments pertaining to the 
applicable implementation plan for the area. Under section 186(a)(4), 
EPA may grant up to two one year extensions if these conditions have 
been met.
    The Administrator's authority to extend attainment dates for 
moderate areas is discretionary. Section 186(a)(4) of the Act provides 
that the Administrator ``may'' extend the attainment date for areas 
meeting the minimum requirements specified above. The provision does 
not dictate or compel EPA to grant extensions to such areas. Therefore, 
EPA will examine the moderate area's air quality planning progress and 
will be disinclined to grant an attainment date extension unless a 
State has, in substantial part, addressed its moderate area CO planning 
obligations. To determine if the State has substantially met these 
planning requirements, EPA will review the State's attainment date 
extension application to assess whether the State has: (1) adopted and 
substantially implemented control measures to satisfy the requirements 
for a moderate CO nonattainment area; and, (2) that reasonable further 
progress is being met for the area.
    If the State cannot make a sufficient demonstration that the area 
has met the extension criteria described above and EPA determines that 
the area has not demonstrated attainment of the CO NAAQS, then the area 
will be reclassified as serious by operation of law pursuant to section 
186(b)(2) of the Act. If an extension is granted, then, at the end of 
the extension year, EPA will review the area's air quality data to 
determine if the area has attained the CO NAAQS. Recall that CO areas 
must have two consecutive years of clean air quality data to 
demonstrate attainment. Consequently, if the area measures a violation 
of the CO NAAQS during the extension year, the area will be unable to 
qualify for a second one year extension. Then, once EPA makes a finding 
of failure to attain the CO NAAQS, the moderate area will be 
reclassified as serious by operation of law.

II. Today's Action

    In today's action, EPA proposes to find that the Clark County CO 
nonattainment area has met the criteria in section 186(b)(4) of the 
CAA, thereby qualifying for a one year attainment date extension. As a 
result of this finding, EPA proposes to grant a one-year extension of 
Clark County's moderate area attainment date from December 31, 1995 to 
December 31, 1996. This proposed finding is based on both EPA's review 
of 1994 and 1995 monitored air quality data for compliance with the CO 
NAAQS and EPA's review of Clark County's application for an attainment 
date extension.

A. Ambient Air Monitoring Data

    The following table lists the location and dates that the eight-
hour CO NAAQS of 9 ppm has been exceeded in Clark County during 1994, 
1995, and 1996. Although the attainment and extension criteria address 
the 1994 and 1995 data, the 1996 data is relevant to later discussion 
in this section.

[[Page 41761]]



               Exceedances of 8-hour Carbon Monoxide National Ambient Air Quality Standard1 in the Clark County, Nevada Nonattainment Area              
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                                                   1994                                    1995                                    1996                 
        Monitoring Site         ------------------------------------------------------------------------------------------------------------------------
                                           Concen.               Date               Concen.              Date               Concen.              Date   
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2850 East Charleston Blvd......  10.6 ppm                         1/4     10.2 ppm                       11/23    10.1 ppm                        1/6   
                                 9.5 ppm                          1/21    ..........................  ..........  10.3 ppm                        1/14  
                                 9.6 ppm                          1/22    ..........................  ..........  10.2 ppm                        3/10  
                                 9.6 ppm                         12/1                                                                                   
                                 10.9 ppm                        12/17 ppm                                                                              
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\1\ The eight-hour carbon monoxide NAAQS is 9 parts per million.                                                                                        
\2\ Concen. = monitored carbon monoxide concentration in parts per million.                                                                             

1. 1994 Data
    During calendar year 1994, Clark County exceeded the eight-hour CO 
NAAQS five times. All of these exceedances occurred at the East 
Charleston monitoring site. These exceedances total four violations of 
the CO NAAQS.
2. 1995 Data
    During calendar year 1995, Clark County exceeded the eight-hour CO 
NAAQS once at the East Charleston monitoring site. Consequently, there 
were no violations of the CO NAAQS in 1995.
3. 1996 Data
    During the first quarter of 1996, Clark County exceeded the eight-
hour CO NAAQS three times; all at the East Charleston monitoring site. 
These exceedances total two violations of the CO NAAQS.
4. Discussion of CO NAAQS Exceedances During the 1995-96 Winter CO 
Season
    Clark County meets the first statutory criterion for an attainment 
date extension by having no more than one exceedance of the CO NAAQS in 
the nonattainment area in 1995. However, this achievement is clouded by 
three exceedances of the CO NAAQS during January and March 1996. 
Furthermore, Clark County raised several concerns with the East 
Charleston monitoring site suggesting that siting problems biased the 
data collected there.
a. Clark County Concerns with East Charleston Monitoring Site
    In recent correspondence from Clark County to EPA, Clark County 
raised several concerns with the siting of the East Charleston monitor 
and proposed several changes to the Clark County monitoring 
network.3 Clark County asserted that the configuration of the East 
Charleston monitoring site is inconsistent with the requirements for 
National Air Monitoring Station (NAMS) given in the Code of Federal 
Regulations (see 40 CFR Part 58.) Clark County's specific concerns were 
as follows: (a) several trees located less than ten meters from the 
station and adjacent block walls, north and west of the station, impede 
the air flow around the monitor; (b) the current probe height is less 
than two meters above the top of the block wall, Clark County suggests 
it should be three meters or more; and, (c) vehicle emissions from a 
nearby apartment complex parking lot may be causing a bias of 
approximately 1.0 ppm during high CO episodes. In sum, Clark County 
asserts that air flow obstructions reducing windspeed in and around the 
sampling probe along with a potential source of nearby vehicle 
emissions both contribute to bias the East Charleston data. Clark 
County suggests that this total bias may contribute 1.4 ppm or 
approximately 10% to the 1995 high CO value of 10.3 ppm.
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    \3\ See correspondence from Michael Naylor, Clark Co. Health 
District to John Kennedy, U.S. Environmental Protection Agency, 
February 7, 1996.
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    Because of these concerns, Clark County asked EPA to delay a 
finding of attainment or nonattainment for the CO NAAQS until new CO 
data is collected during October to December of 1996 at new monitoring 
sites. Towards this end, Clark County proposed the following actions: 
(a) to relocate the East Charleston monitoring station within the same 
neighborhood; (b) to increase the number of EPA recognized neighborhood 
sites by adding monitoring sites at East Sahara and East Flamingo 
Boulevards; (c) to identify and add a suitable microscale monitoring 
station with high pedestrian traffic; and, (d) to request designation 
of the Paul Meyer Park monitor in Spring Valley as a background CO 
monitoring site.
    In response to Clark County's concerns and proposal, EPA and Clark 
County have agreed to revise the CO monitoring network in Clark County. 
The present East Charleston monitoring site will continue to operate 
according to all applicable protocols until its lease expires in 1997. 
Three new monitoring sites will be added to the Clark County air 
quality monitoring system before the 1996-97 winter CO season: two 
neighborhood scale sites, one at Sunrise Acres Elementary School and 
the other at Crestwood Elementary School in the East Charleston area; 
and, a microscale site on Las Vegas Boulevard at Tropicana. Both the 
neighborhood scale site at Sunrise Acres Elementary School and the 
microscale site on Las Vegas Boulevard will be potential National Air 
Monitoring Stations. As such, they must meet federal monitoring 
requirements and their siting and operating protocols are subject to 
EPA approval. To determine accurately and scientifically the air 
quality status of Clark County in 1996, it is essential that Clark 
County install these three new monitoring sites before October 1, 1996 
and operate them correctly during the 1996-97 winter CO season.
b. EPA Review of Other CO Data Collected in East Charleston Area During 
1995-96 Winter CO Season
    During the 1995-96 winter CO season, two special purpose CO 
monitoring sites were operated within a city block of the East 
Charleston monitoring station: the ``Proximity'' site (2850 East 
Charleston Boulevard) and the ``Microscale'' (2801 East Charleston 
Boulevard) site. The data collected at these monitoring sites are not 
used for regulatory purposes and these monitors may have siting issues 
independent of those at the East Charleston station.
    However, EPA staff examined the data collected at these two sites 
and compared them to the data obtained at the East Charleston station 
over the 1995-96 winter CO season on the days where exceedances of the 
CO NAAQS were observed at any of the three monitors. For these days, 
EPA compared the eight-hour maximum average value at the three sites to 
determine qualitatively the extent of the CO problem in the East 
Charleston area and

[[Page 41762]]

the extent of any inconsistencies between East Charleston data and data 
collected at other CO monitors in the area.
    The comparison shows that data from the three sites were very 
similar. On the exceedance days, the daily maximum eight-hour average 
values almost always occurred during the same time period at all three 
sites. Also, on the nine days where an exceedance of the CO NAAQS was 
observed at any of the three monitors, East Charleston recorded three 
exceedances, Proximity recorded five exceedances, and Microscale 
recorded seven exceedances. This suggests that exceedances at East 
Charleston did not appear to be anomalies solely derived from siting 
problems. Ambient CO values near or above the CO NAAQS appear to occur 
consistently in the East Charleston area.
    The exception was the period between November 30, 1995 and December 
21, 1995 when the East Charleston monitoring site was operated under a 
different protocol. The sampling probe height at East Charleston was 
raised from 3.7 meters to 14.2 meters while the sampling probes at the 
Proximity and Microscale sites remained at 10 and 3.5 meters 
respectively. Data collected in January 1996 suggest that CO values 
observed at the East Charleston monitor during this November/December 
timeframe were lower than they otherwise might have been due to the 
difference in probe height. Parallel monitoring at the two different 
probe heights during the January 1996 exceedances show CO values were 
11-13% lower at 14.2 meters than when measured at 3.7 meters 4. 
Also, in contrast, where the East Charleston site measured no 
exceedances of the CO NAAQS during this timeframe, the Proximity site 
measured CO values greater than the CO NAAQS once and the Microscale 
site measured CO values greater than the NAAQS three times. After 
December 21, 1995, Clark County returned the East Charleston sampling 
probe to 3.7 meters at EPA's request.5 EPA's request was 
consistent with the National Air Monitoring Station operating protocols 
used at the East Charleston site since its inception fifteen years ago.
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    \4\ See February 7, 1996 Michael Naylor to John Kennedy 
correspondence at page 6. January 1996 exceedances were 
approximately 10.3 ppm, measured at 3.7 meters, while CO values 
measured at 14.2 meters were approximately 9.0 ppm.
    \5\ See correspondence from David P. Howekamp, U.S. 
Environmental Protection Agency to Michael Naylor, dated December 
15, 1995.
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    In summary, data exists in addition to the data collected at East 
Charleston to suggest that frequency and severity of exceedances of the 
CO NAAQS at the East Charleston site do not appear to be anomalies 
solely derived from site problems. Under predictable weather patterns 
and meteorology, ambient CO values near or above the CO NAAQS occur 
consistently in the East Charleston area.
5. Conclusion
    Clark County meets the first statutory criterion for an attainment 
date extension by having no more than one exceedance of the CO NAAQS in 
the nonattainment area in 1995. However, this achievement is clouded by 
3 exceedances of the CO NAAQS in January and March of 1996.
    EPA will not disqualify the January to March winter 1996 CO season 
monitoring data from the East Charleston station without further review 
and conclusive evidence that it is inaccurate. Clark County should 
operate the East Charleston monitor according to proper protocols 
through the coming 1996-97 winter CO season in parallel with the new 
monitors at Sunrise Acres Elementary School, Crestwood Elementary 
School, and on Las Vegas Boulevard & Tropicana. Then, in collaboration 
with Nevada Division of Environmental Protection and the Clark County 
Health District, EPA will compare the East Charleston data to data from 
the replacement site at Sunrise Acres Elementary School to determine 
what bias, if any, exists in the East Charleston data. In early 1997, 
EPA will use the data from Crestwood Elementary School and Las Vegas 
Boulevard, along with data from the rest of the Clark County air 
quality monitoring network, to determine Clark County's air quality 
status.

B. Review of Clark County's Attainment Date Extension Request

    On March 28, 1996, Nevada submitted Clark County's application for 
a one-year extension of the moderate CO attainment date from December 
31, 1995 to December 31, 1996.6 Clark County does not have two 
consecutive years of clean data needed to show attainment of the CO 
NAAQS. So, as discussed earlier, EPA may grant a one year attainment 
date extension if Clark County meets the following two criteria: (1) no 
more than one exceedance of the CO NAAQS at any monitoring site in the 
nonattainment area in 1995, and (2) compliance with the requirements 
and commitments pertaining to the applicable implementation plan for 
the area. Having reviewed Clark County's ambient air quality data for 
exceedances of the CO NAAQS, the remainder of this proposal will review 
whether or not Clark County meets the second criterion.
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    \6\ See ``1996 Extension Year Application for the Las Vegas 
Valley Carbon Monoxide Nonattainment Area,'' Clark County Department 
of Comprehensive Planning, March 1996.
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1. Review of SIP Implementation and Compliance
    To determine whether or not Nevada and Clark County have complied 
with the applicable SIP, EPA will examine the air quality planning 
progress made in Clark County. In this assessment, EPA will review 
recent State implementation plan submittals and the extension 
application to determine if Nevada and Clark County have: (a) adopted 
and implemented the control measures needed to satisfy the CAA 
requirements for a moderate CO nonattainment area; and (b) made 
reasonable further progress towards meeting the CO NAAQS. These 
criteria are used as part of determining compliance with the applicable 
SIP because Nevada and Clark County have recently submitted amendments 
to several of these moderate area control measures. EPA has yet to 
review, approve, and include these recent amendments in the applicable 
SIP.
a. Compliance With Moderate Area Planning Requirements
    The CAA requires moderate CO nonattainment areas, such as Clark 
County, to implement the following control measures and planning 
requirements: (a) enhanced inspection and maintenance of motor vehicles 
(enhanced I/M) for CO; (b) an oxygenated fuels program requiring 
gasoline to be sold with 2.7% oxygenate by weight; (c) areawide vehicle 
miles traveled (VMT) forecasts and linked contingency measures; (d) a 
demonstration of attainment for the CO NAAQS; and, (e) any additional 
control measures needed to attain the CO NAAQS.7
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    \7\ For more information on air quality planning requirements, 
see section 187(a) of the CAA, the ``General Preamble to Title I of 
the CAA'' (57 FR 13498-13570, April 16, 1992 and 57 FR 18070-18077, 
April 28, 1992), and the ``Technical Support Document to Aid States 
with the Development of Carbon Monoxide State Implementation Plans'' 
(EPA-452/R-92-003, July 1992)
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    Nevada has submitted two enhanced I/M programs for Clark County. 
Nevada submitted its first enhanced I/M program on July 28, 1994. It 
was intended to comply with EPA regulations extant at the time (see 57 
FR 52950, November 5, 1992). Since then, Nevada redesigned its enhanced 
I/M program to take advantage of increased flexibility offered by EPA's 
revised

[[Page 41763]]

enhanced I/M program regulations (see 60 FR 48029, September 18, 1995). 
Thus, Clark County's present enhanced I/M program is designed to meet 
EPA's ``low'' enhanced I/M performance standard. Nevada submitted this 
program to EPA on March 20, 1996. This low enhanced I/M program was not 
fully implemented in Clark County during the 1995-96 winter CO season. 
In September 1995, Nevada began implementing its low enhanced I/M 
program. Program improvements included connecting test analyzers to a 
common network over approximately 290 inspection stations. However, on 
road testing of the in-use registered motor vehicle population (remote 
sensing) was not implemented during the 1995-96 winter CO season. 
Nevada is scheduled to begin remote sensing in July 1996.
    Requiring a minimum 2.5% oxygenate by weight, Clark County first 
implemented its oxygenated fuels program in November of 1989. By 
November 1991, the oxygenated fuels regulation, Health District 
Regulation--Section 53, was revised to meet the minimum 2.7% oxygenate 
by weight requirement of the CAA. Clark County submitted this 
regulation to EPA on July 6, 1992. Since this submittal, Clark County 
has revised its oxygenated fuels regulation several times within the 
2.7% oxygenate content requirement. Clark County's latest submittal of 
the oxygenated fuels regulation (revised and adopted July 27, 1995) to 
EPA was on October 4, 1995.
    Clark County provided vehicle miles traveled forecasts, contingency 
measures, and an attainment demonstration in three CO plan submittals. 
Clark County submitted its first CO plan on November 17, 1992 to comply 
with the CO plan submittal requirements of the CAA. Then, Clark County 
provided a second revised plan submittal on October 4, 1995. The second 
revision was required due to changes in the enhanced I/M program and 
resulting changes in Clark County's CO control strategy. Clark County 
submitted the third revised CO plan on November 8, 1995 including State 
and local commitments to control measures in 2000 and 2010. Assuming 
implementation of these enforceable commitments allowed transportation 
planning agencies to demonstrate that current transportation plans and 
programs will conform to the CO plan's emissions budget in 2000 and 
2010.
    Also, in the October 4, 1995 CO plan submittal, Clark County 
included a wintertime Reid vapor pressure (RVP) fuel requirement, a 
control measure not required by the CAA. However, Clark County 
determined that this added measure was needed to attain the CO NAAQS. 
The Nevada Board of Agriculture subsequently amended the Nevada 
Administrative Code to require a wintertime RVP of 9 pounds per square 
inch (psi).
    In conclusion, Clark County has adopted and submitted items 
addressing the planning requirements of the CAA for moderate CO areas. 
Clark County's adopted CO control strategy for the 1995-96 winter CO 
season included the following elements: a low program standard enhanced 
vehicle I/M program, a 2.7% oxygenated fuels program, and a wintertime 
RVP requirement. However, the low enhanced I/M program was not fully 
implemented during the 1995-96 winter CO season. EPA expects Clark 
County's enhanced I/M program to be fully implemented before the 1996-
97 winter CO season. Furthermore, Clark County submitted to EPA all CAA 
required plan elements such as VMT forecasts, contingency measures, and 
an attainment demonstration for the CO NAAQS.
b. Reasonable Further Progress Towards Meeting the CO NAAQS
    Both the number and severity of violations of the CO NAAQS have 
decreased since 1990.8 In 1990, Clark County violated the CO NAAQS 
thirteen times with a 14.2 ppm design value. In comparison, during 
1995, Clark County exceeded the CO NAAQS once with a 9.2 ppm design 
value. The frequency and severity of CO NAAQS violations have 
decreased. Furthermore, these improvements in air quality coincide with 
implementation of the control measures described above, especially the 
oxygenated fuels program.
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    \8\ See Attachments 1-4 to ``1996 Extension Year Application for 
the Las Vegas Valley Carbon Monoxide Nonattainment Area,'' Clark 
County Department of Comprehensive Planning, March 1996.
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2. Conclusion
    Given the planning actions and reasonable further progress by Clark 
County, EPA proposes that Clark County meets the second statutory 
criterion required for a one year attainment date extension: it has 
adopted, submitted, and, for the most part, implemented, the control 
measures needed to satisfy the requirements for a moderate CO 
nonattainment area; it has adopted and submitted the planning 
requirements for a moderate CO area; and, it has made reasonable 
further progress towards meeting the CO NAAQS.

III. Consequences of Today's Action

    If EPA takes final action on this proposed finding that Clark 
County has met the criteria for an attainment date extension, then 
Clark County will be granted a one year attainment date extension and 
will remain classified as a moderate CO nonattainment area. After 
December 31, 1996, EPA will again review the air quality data for Clark 
County to determine if it has attained the CO NAAQS.
    If Clark County measures violations of the CO NAAQS during 1996, 
the area will be unable to qualify for a second one year extension. 
Then, after an EPA finding of failure to attain the CO NAAQS, Clark 
County would be reclassified as a serious carbon monoxide nonattainment 
area by operation of law.

IV. Executive Order (EO) 12866

    Under E.O. 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 Executive Order. The Executive Order 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), 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 Agency has determined that extending attainment dates, as 
proposed today, would not result in the effects identified in section 
3(f). Under section 186(a)(4) of the CAA, attainment date extensions 
are based upon air quality conditions and planning considerations and 
are either administrative in nature, or must occur by operation of law 
in light of certain air quality conditions. They do not, in-and-of-
themselves, impose any new requirements on any sectors of the economy.

V. Regulatory Flexibility

    Under the Regulatory Flexibility Act, 5 U.S.C. 601 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 that the rule will not have a 
significant economic impact on a substantial number of small entities. 
Small entities include small businesses, small not-for-

[[Page 41764]]

profit enterprises, and government entities with jurisdiction over 
populations of less than 50,000.
    As discussed in section IV. of this notice, attainment date 
extensions under section 186(a)(4) of the CAA do not create any new 
requirements. Therefore, I certify that today's proposed action does 
not have a significant impact on small entities.

VI. Unfunded Mandates

    Under sections 202, 203 and 205 of the Unfunded Mandates Reform Act 
of 1995 (Unfunded Mandates Act), signed into law on March 22, 1995, EPA 
must assess whether various actions undertaken in association with 
proposed or final regulations include a Federal mandate that may result 
in estimated costs of $100 million or more to the private sector, or to 
State, local or tribal governments in the aggregate. EPA believes, as 
discussed above, that the proposed finding that Clark County 
nonattainment area meets the criteria in section 186(a)(4) and thereby 
qualifies for an attainment date extension is a factual determination 
based upon air quality considerations and must occur by operation of 
law and, hence, does not impose any Federal intergovernmental mandate, 
as defined in section 101 of the Unfunded Mandates Act.

List of Subjects in 40 CFR Part 81

    Environmental protection, Air pollution control, Intergovernmental 
relations, Carbon monoxide.

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

    Dated: July 22, 1996.
Felicia Marcus,
Regional Administrator.
[FR Doc. 96-20370 Filed 8-9-96; 8:45 am]
BILLING CODE 6560-50-P