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

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 81

[NV029-0003; FRL-5847-5]

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 not attained the CO national

ambient air quality standard (NAAQS) by the Clean Air Act (CAA) after

having received a one year extension from the mandated attainment date

of December 31, 1995 for moderate nonattainment areas to December 31,

1996. This finding is based on EPA's review of monitored air quality

data for compliance with the CO NAAQS. If EPA takes final action on

this proposed finding, the Clark County, Nevada nonattainment area will

be reclassified by operation of law as a serious nonattainment area. As

a result of a reclassification the State will have additional time to

submit a new State implementation plan (SIP) providing for attainment

of the CO NAAQS by no later than December 31, 2000, the CAA attainment

deadline for serious CO areas.

DATES: Written comments on this proposal must be received by July 28,

1997.

ADDRESSES: Written comments should be sent to: Julia Barrow, Chief, Air

Planning Office, AIR-2, U.S. Environmental Protection Agency, Region 9,

75 Hawthorne Street, San Francisco, California 94105.

The rulemaking docket for this document, Docket No. NV029-0003, 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 Division, Air Planning Office, AIR-2,75 Hawthorne Street, San

Francisco, California 94105.

Copies of the docket are also available at the State and County

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: Larry Biland, AIR-2, Air Division,

U.S. Environmental Protection Agency, Region 9, 75 Hawthorne Street,

San Francisco, California 94105, (415) 744-1227.

SUPPLEMENTARY INFORMATION:

I. Background

A. CAA Requirements and EPA Actions Concerning Designation and

Classifications

The Clean Air Act Amendments of 1990 (CAA) were enacted on November

15, 1990. Under section 107(d)(1)(C) of the CAA, each carbon monoxide

(CO) area designated nonattainment prior to enactment of the 1990

Amendments, such as the Clark County area, was designated nonattainment

by operation of law upon enactment of the 1990 Amendments. Under

section 186(a) of the Act, 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), such as the Clark County area, were classified as

moderate. These nonattainment designations and classifications were

codified in 40 CFR part 81. See 56 FR 56694 (November 6, 1991).

States containing areas that were classified as moderate

nonattainment by 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, 1995.1

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\1\ The moderate area SIP requirements are set forth in section

187(a) of the Act and differ depending on whether the area's design

value is below or above 12.7 ppm. The Clark County area has a design

value below 12.7 ppm. 40 CFR 81.303.

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B. 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. EPA

may, in its discretion, grant such an extension if the state has: (1)

complied with the requirements and commitments pertaining to the

applicable implementation plan for the area, and (2) the area has

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. Under section 186(a)(4), EPA may grant up to two such extensions

if these conditions have been met. EPA has granted Clark County one

extension to December 31, 1996. (40 CFR Part 52 Vol. 61, No. 216,

Wednesday, Nov. 6, 1996).

C. 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, whether the Clark County area has attained

the CO NAAQS. Under section 186(b)(2)(A), if EPA finds that the 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 document 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

[[Page 34420]]

whether an area has two years (or eight consecutive quarters) of clean

air quality data.2 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, where an area has received

an extension, EPA will determine whether an area's air quality has met

the CO NAAQS by the required date, or in the case of Clark County by

the extended date of December 31, 1996, based upon the most recent two

years of air quality data.

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\2\ See generally 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.3 EPA has

promulgated two NAAQS for CO: an 8-hour average concentration and a 1-

hour average concentration. Because there were no violations of the 1-

hour standard in the Clark County area, this notice addresses only the

air quality status of the Clark County area with respect to the 8-hour

standard. The 8-hour CO NAAQS requires that not more than one non-

overlapping 8-hour average in any consecutive two-year period 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 8-hour CO NAAQS at a given monitoring site within the same two-

year period constitutes a violation of the CO NAAQS.

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\3\ 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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II. Today's Action

By today's action, EPA is proposing to find that the Clark County

CO nonattainment area has failed to attain the CO NAAQS by December 31,

1996. This proposed finding is based upon air quality data showing

exceedances of the CO NAAQS during 1995 and 1996, resulting in two

violations in 1996.

A. Ambient Air Monitoring Data

The following table lists each of the monitoring sites in the Clark

County CO nonattainment area where the 8-hour CO NAAQS has been

exceeded during 1995 and 1996.

Exceedances of 8-hour Carbon Monoxide National Ambient Air Quality Standard\1\ in the Clark County, Nevada

Nonattainment Area

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1995 1996

Monitoring site ---------------------------------------------------------------------------

Concentration \2\ Date Concentration \2\ Date

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2850 East Charleston Blvd........... 10.2 ppm............... 11/23 10.1 ppm............... 1/6

....................... ........... 10.3 ppm............... 1/14

....................... ........... 10.2 ppm............... 3/10

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\1\ The eight-hour carbon monoxide NAAQS is 9 parts per million.

\2\ Concentration = monitored carbon monoxide concentration in parts per million.

1. 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.

2. 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.

3. Discussion of CO NAAQS Exceedances During the 1995-96 Winter CO

Season

Clark County qualified for an attainment date extension to December

31, 1996 by having no more than one exceedance of the CO NAAQS in the

nonattainment area in 1995. However, this achievement was clouded by

three exceedances of the CO NAAQS during January and March 1996. Clark

County raised several concerns with the East Charleston monitoring site

which recorded the violations, suggesting that siting problems biased

the data collected there.

a. Clark County Concerns With East Charleston Monitoring Site

In 1995 and early 1996, Clark County raised to EPA several concerns

with the siting of the East Charleston monitor, and also proposed

several changes to their CO monitoring network.4 Clark

County asserted that the configuration of the East Charleston

monitoring site was inconsistent with the requirements for National Air

Monitoring Stations (NAMS) given in the Code of Federal Regulations

(see 40 CFR Part 58) and this was biasing the data. Because of these

concerns, Clark County asked EPA to delay a finding of attainment or

nonattainment for the 1995 attainment deadline until new CO data was

collected during October to December of 1996 at the 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, and at Crestwood Elementary School in the East Charleston

Blvd. vicinity, and, (c) to add a microscale monitoring station with

high pedestrian traffic at the Las Vegas Blvd. and Tropicana Ave.

intersection.

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\4\ See correspondence from Michael Naylor, Clark Co. Health

District to John Kennedy, U.S. Environmental Protection Agency,

February 7, 1996.

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In response to Clark County's concerns and proposal, EPA agreed

with revisions to the CO monitoring network in Clark County. The East

Charleston monitoring site continued to operate according to all

applicable protocols until its lease expired in 1997. Three new

monitoring sites were added to the Clark County air monitoring network

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,

the MGM site, located on Las Vegas Blvd. at Tropicana. The Sunrise

Acres site was the direct replacement site for the high-CO East

Charleston site.

At the close of the winter 96-97 season Region 9 and the State of

Nevada examined whether East Charleston CO levels correlated with the

levels at

[[Page 34421]]

Sunrise Acres. Based on November 1996 to March 1997 CO data, EPA staff

determined that there was a strong correlation of peak 1- and 8-hour

average CO levels at East Charleston and Sunrise Acres. A comparison of

peak 8-hour CO concentrations at Sunrise Acres and the East Charleston

site showed that Sunrise Acres values consistently exceeded East

Charleston levels. With the continued operation of Sunrise Acres and

MGM replacement sites, and the value-added Crestwood site, Region 9

supported Clark County's shutdown of the East Charleston site. It is

implicit that in showing that Sunrise Acres closely tracked East

Charleston CO levels, that previous East Charleston data were valid.

Previous Clark County assertions that the configuration of the East

Charleston siting positively biased previously collected CO data are

inconsistent with EPA findings. Thus EPA considers data from the East

Charleston station collected in 1995-96 to be valid for regulatory

purposes. EPA is relying on this data in the proposed finding that

Clark County failed to attain the Federal CO standard on December 31,

1996.

B. SIP Requirements for Serious CO Areas

CO nonattainment areas reclassified as serious under section

186(b)(2) of the CAA are required to submit, within 18 months of the

area's reclassification, SIP revisions demonstrating attainment of the

CO NAAQS as expeditiously as practicable but no later than December 31,

2000. The serious CO area planning requirements are set forth in

section 187(b) of the CAA. EPA has issued two general guidance

documents related to the planning requirements for CO SIPs. The first

is the ``General Preamble for the Implementation of Title I of the

Clean Air Act Amendments of 1990'' that sets forth EPA's preliminary

views on how the Agency intends to act on SIPs submitted under Title I

of the Act. See generally 57 FR 13498 (April 16, 1992) and 57 FR 18070

(April 28, 1992). The second general guidance document for CO SIPs

issued by EPA is the ``Technical Support Document to Aid the States

with the Development of Carbon Monoxide State Implementation Plans,''

July 1992.

If the Clark County area is reclassified to serious, the State

would have to submit a SIP revision to EPA within 18 months of the

final reclassification that, in addition to the attainment

demonstration, includes: (1) Any new measures necessary to attain the

standard; (2) a forecast of vehicle miles traveled (VMT) for each year

before the attainment year and provisions for annual updates of these

forecasts; (3) adopted contingency measures; and (4) adopted

transportation control measures and strategies to offset any growth in

CO emissions from growth in VMT or number of vehicle trips. See CAA

sections 187(a)(7), 187(a)(2)(A), 187(a)(3), 187(b)(2), and 187(b)(1).

Upon reclassification, contingency measures in the moderate area plan

for the Clark County area must be implemented.

III. 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 the finding of failure to attain

proposed today would result in none of the effects identified in

section 3(f). Under section 186(b)(2) of the CAA, findings of failure

to attain and reclassification of nonattainment areas are based upon

air quality considerations and 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. In addition,

because the statutory requirements are clearly defined with respect to

the differently classified areas, and because those requirements are

automatically triggered by classifications that, in turn, are triggered

by air quality values, findings of failure to attain and

reclassification cannot be said to impose a materially adverse impact

on State, local, or tribal governments or communities.

IV. 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-profit

enterprises, and government entities with jurisdiction over populations

of less than 50,000.

As discussed in section III of this notice, findings of failure to

attain and reclassification of nonattainment areas under section

186(b)(2) of the CAA do not in-and-of-themselves create any new

requirements. Therefore, I certify that today's proposed action does

not have a significant impact on small entities.

V. 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 of failure to attain and

reclassification of the Clark County nonattainment area are factual

determinations based upon air quality considerations and must occur by

operation of law and, hence, do 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, Carbon monoxide,

Intergovernmental relations.

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

Dated: June 16, 1997.

Felicia Marcus,

Regional Administrator.

[FR Doc. 97-16754 Filed 6-25-97; 8:45 am]

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