Clean Air Act Reclassification; Arizona-Phoenix Nonattainment Area; PM-10

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 81

[FRL-5217-3]

Clean Air Act Reclassification; Arizona-Phoenix Nonattainment

Area; PM-10

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: In this action EPA proposes to find that the Phoenix

metropolitan PM-10 nonattainment area has not attained the PM-10

national ambient air quality standards (NAAQS) by the Clean Air Act

(CAA) mandated attainment date for moderate nonattainment areas.

Section 188(c)(1) of the Act established an attainment date of no later

than December 31, 1994 for areas classified as moderate nonattainment

areas under section 107(d)(4)(B) of the CAA. This proposed finding is

based on monitored air quality data for the PM-10 NAAQS during the

years 1992-94. If EPA takes final action on this proposed finding, the

Phoenix Planning Area (PPA) will be reclassified by operation of law as

a serious nonattainment area for PM-10 under section 188(b)(2)(A) of

the CAA.

DATES: Comments on this proposed finding must be received in writing by

July 7, 1995.

ADDRESSES: Comments should be addressed to Robert Pallarino, U.S.

Environmental Protection Agency, Region 9, Air and Toxics Division, Air

Planning Branch, Plans Development Section (A-2-2), 75 Hawthorne

Street, San Francisco, California 94105.

FOR FURTHER INFORMATION CONTACT: Robert S. Pallarino, U.S. EPA, Region

9, Air and Toxics Division, Air Planning Branch, Plans Development

Section (A-2-2), 75 Hawthorne Street, San Francisco, California 94105,

(415) 744-1212.

SUPPLEMENTARY INFORMATION:

I. Background

A. CAA Requirements and EPA Actions Concerning Designation and

Classification

On November 15, 1990, the date of enactment of the 1990 Clean Air

Act Amendments, PM-10 areas meeting the qualifications of section

107(d)(4)(B) of the Act were designated nonattainment by operation of

law. Once an area is designated nonattainment, section 188 of the Act

outlines the process for classification of the area and establishes the

area's attainment date. Pursuant to section 188(a), all PM-10

nonattainment areas were initially classified as moderate by operation

of law upon designation as nonattainment. These nonattainment

designations and moderate area classifications were codified in 40 CFR

part 81 in a Federal Register document published on November 6, 1991

(56 FR 56694).

States containing areas which were designated as moderate

nonattainment by operation of law under section 107(d)(4)(B) were to

develop and submit state implementation plans (SIPs) to provide for the

attainment of the PM-10 NAAQS. Pursuant to section 189(a)(2), those SIP

revisions were to be submitted to EPA by November 15, 1991.

B. Reclassification as Serious Nonattainment

EPA has the responsibility, pursuant to sections 179(c) and

188(b)(2) of the Act, of determining within 6 months of the applicable

attainment date, whether PM-10 nonattainment areas have attained the

NAAQS. Section 179(c)(1) of the Act provides that these determinations

are to be based upon an area's ``air quality as of the attainment

[[Page 30047]] date'', and section 188(b)(2) is consistent with this

requirement. EPA makes the determinations of whether an area's air

quality is meeting the PM-10 NAAQS based upon air quality data gathered

at monitoring sites in the nonattainment area and entered into the

Aerometric Information Retrieval System (AIRS). These data are reviewed

to determine the area's air quality status in accordance with EPA

guidance at 40 CFR part 50, Appendix K.

Pursuant to Appendix K, attainment of the annual PM-10 standard is

achieved when the annual arithmetic mean PM-10 concentration is equal

to or less than 50 g/m\3\. Attainment of the 24 hour standard

is determined by calculating the expected number of exceedances of the

150 g/m\3\ limit per year. The 24 hour standard is attained

when the expected number of exceedances is 1.0 or less. A total of 3

consecutive years of clean air quality data is generally necessary to

show attainment of the 24 hour and annual standards for PM-10. A

complete year of air quality data, as referred to in 40 CFR part 50,

Appendix K, is comprised of all 4 calendar quarters with each quarter

containing data from at least 75 percent of the scheduled sampling

days.

Under section 188(b)(2)(A) a moderate PM-10 nonattainment area must

be reclassified as serious by operation of law after the statutory

attainment date if the Administrator finds that the area has failed to

attain the NAAQS. Pursuant to section 188(b)(2)(B) of the Act, EPA must

publish a document in the Federal Register identifying those areas that

failed to attain the standard and the resulting reclassifications.

II. Today's Action

EPA is, by today's action, proposing to find that the PPA did not

attain the PM-10 NAAQS by the required attainment date of December 31,

1994. As discussed below, this proposed finding is based upon air

quality data which revealed violations of the PM-10 NAAQS during 1992-

1994.

A. Ambient Air Monitoring Data

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

where the 24 hour PM-10 NAAQS has been exceeded during 1992-1994:

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24 hour

Monitoring site concentration Date

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4732 S. Central, PX................... 171 g/ 11/20/92

m\3\

4732 S. Central, PX................... 158 g/ 12/2/92

m\3\

1475 E. Pecos, CHAN................... 156 g/ 11/20/92

m\3\

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The two monitoring sites in the PPA that recorded exceedances of

the PM-10 NAAQS operate on a one in six day sampling schedule.

Generally, if PM-10 sampling is scheduled less than every day, EPA

requires the adjustment of observed exceedances to account for

incomplete sampling. The method for adjusting the observed exceedances

is described in 40 CFR Part 50, Appendix K, section 3.1. In the case of

the Phoenix site, two exceedances of the 24 hour NAAQS were observed in

1992. After adjusting for incomplete sampling, the number of

exceedances of the NAAQS in 1992 at this site was 13.1. In the case of

the Chandler site, one exceedance of the 24 hour NAAQS was observed in

1992. After adjusting for incomplete sampling, the number of

exceedances of the NAAQS in 1992 at this site was 11.5.

According to 40 CFR part 50, the 24 hour NAAQS is attained when the

expected number of days per calendar year with a 24 hour average

concentration above 150 g/m\3\ is equal to or less than one.

In the simplest case, the number of expected exceedances at a site is

determined by recording the number of exceedances in each calendar year

and then averaging them over the past three calendar years. Therefore

from 1992-1994, the number of expected exceedances at the Phoenix and

Chandler monitoring sites were 4.4 and 3.8, respectively. These

exceedances cause both the Phoenix site and the Chandler site to be in

violation of the 24 hour PM-10 NAAQS.

In addition to violations of the 24 hour NAAQS, the annual standard

has not been attained at one monitoring site. The East Pecos site in

Chandler had an annual average of 55 g/m\3\, based on the

monitoring data collected during 1992-1994.

B. SIP Requirements for Serious Areas

PM-10 nonattainment areas reclassified as serious under section

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

area's reclassification, SIP revisions providing for the implementation

of best available control measures (BACM) no later than four years from

the date of reclassification. The SIP also must contain a demonstration

that the implementation of BACM will provide for attainment of the PM-

10 NAAQS no later than December 31, 2001. EPA has provided specific

guidance on developing serious area PM-10 SIP revisions in an addendum

to the General Preamble to Title I of the Clean Air Act. See 59 FR

41998 (August 16, 1994).

III. Request for Public Comment

The EPA is requesting comment on all aspects of today's proposal.

As indicated at the outset of this notice, EPA will consider any

comments received by July 7, 1995.

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 the finding of failure to attain

proposed today would result in none of the effects identified in

section 3(f). Under section 188(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.

V. Regulatory Flexibility

Under the Regulatory Flexibility Act, 5 U.S.C. 600 et seq., EPA

must prepare a regulatory flexibility analysis assessing the impact of

any proposed or final rule on small entities. 5 U.S.C. 603 and 604.

Alternatively, EPA may certify 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 of less than

50,000.

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

attain and [[Page 30048]] reclassification of nonattainment areas under

section 188(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.

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 earlier in section IV of this notice,

that the proposed finding of failure to attain and reclassification of

the Phoenix Planning 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, Intergovernmental

relations, Particulate matter.

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

Dated: May 25, 1995.

David P. Howekamp,

Acting Regional Administrator.

[FR Doc. 95-13925 Filed 6-6-95; 8:45 am]

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