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

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]

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