Transportation Conformity; Proposed Approval of Petition for Exemption From Nitrogen Oxides Provisions, Colorado

SUMMARY: The Environmental Protection Agency (EPA) is proposing to

approve a petition that was submitted pursuant to section 182(f) of the

Clean Air Act (as amended in 1990) (CAA) by the Denver Regional Council

of Governments (DRCOG) requesting that the Denver metropolitan area, an

ozone nonattainment area classified as transitional, be exempted from

the requirements regarding the control of oxides of nitrogen (NOX)

imposed by the Federal conformity rules. These rules waive certain

NOX requirements if an exemption under section 182(f) is granted

by EPA. The EPA has indicated in relevant guidance that areas

(including transitional areas, like the Denver Metropolitan area)

demonstrating attainment based on ambient air quality monitoring data

without additional NOX reductions satisfy the exemption test.

DATES: Comments must be received on or before April 24, 1995.

ADDRESSES: Written comments should be addressed to: Douglas M. Skie,

Chief, Air Quality Branch (8ART-AP), United States Environmental

Protection Agency, Region VIII, 999 18th Street, suite 500, Denver,

Colorado 80202-2466.

Copies of the DRCOG petition and other information relevant to this

action are available for inspection between 8 a.m. and 4 p.m. Monday

through Friday at the following locations: United States Environmental

Protection Agency, Region VIII, Air Quality Branch (8ART-AP), 999 18th

Street, suite 500, Denver, Colorado 80202-2466.

Air and Radiation Docket and Information Center, United States

Environmental Protection Agency, 401 M. Street SW., Washington, DC

20460

Anyone wishing to review this petition at the Denver EPA Regional

office is asked to contact the person below to schedule an appointment

24 hours in advance.

FOR FURTHER INFORMATION CONTACT: Ms. Aundrey C. Wilkins, SIP Section

(8ART-AP), Air Programs Branch, United States Environmental Protection

Agency, Region VIII, 999 18th Street, Suite 500, Denver, Colorado,

80202-2466, telephone (303) 294-1379.

SUPPLEMENTARY INFORMATION:

I. Background

Section 182(f) of the Clean Air Act contains requirements for major

stationary NOX sources in marginal and above ozone nonattainment

areas and in an ozone transport region. Section 182(f) also specifies

circumstances under which the NOX requirements would be limited or

would not apply.

Under section 182(f)(1)(A), an exemption from the NOX

requirements may be granted for nonattainment areas outside an ozone

transport region if EPA determines that ``additional reductions of

NOX would not contribute to attainment'' of the ozone NAAQS in

those areas. EPA has indicated that in cases where a nonattainment area

is demonstrating attainment with 3 consecutive years of air quality

monitoring data, without having implemented the section 182(f) NOX

provisions, it is clear that this test is met since ``additional

reductions of NOX would not contribute to attainment'' of the

NAAQS in that area.

EPA's general and transportation conformity rules reference the

section 182(f) exemption process as a means for exempting affected

areas from certain NOX conformity requirements. See 58 FR 62197,

November 24, 1993, Transportation Conformity, and 58 FR 63240, November

30, 1993, General Conformity.

This interpretation is discussed in a May 27, 1994 memorandum from

John S. Seitz, Director, Office of Air Quality Planning and Standards

(OAQPS), entitled ``Section 182(f) Nitrogen Oxides (NOX)

Exemptions--Revised Process and Criteria.'' This memorandum revised

relevant portions of previously-issued OAQPS guidance dated December,

1993, entitled ``Guideline for Determining the Applicability of

Nitrogen Oxide Requirements under Section 182(f).'' Both documents

address EPA's policy regarding NOX exemptions for areas outside an

ozone transport region that have air quality monitoring data showing

attainment. The section 182(f) NOX provisions and the guidance

cited above apply to marginal and above ozone nonattainment areas, but

not nonclassifiable ozone nonattainment areas (i.e., submarginal,

transitional, and incomplete/no data). However, on June 17, 1994, EPA

published a document entitled ``Conformity; General Preamble for

Exemption from Nitrogen Oxides Provisions'' (59 FR 31238) (``General

Preamble''). This document provides guidance on the exemption of

nonclassifiable ozone nonattainment areas, outside an ozone transport

region, from the conformity rule's NOX provisions based on air

quality monitoring data showing attainment. As a transitional ozone

nonattainment area, the Denver metropolitan area falls within the

``nonclassifiable'' category.

Pursuant to section 182(f), a person or State may petition EPA to

grant an exemption which would relieve the relevant nonattainment area

from certain requirements of the general and transportation conformity

rule. DRCOG submitted a NOX exemption petition on May 25, 1994 and

submitted supporting documentation via a letter dated August 1, 1994.

Ambient air quality data provided with the DRCOG petition showed no

violations of the ozone NAAQS during the three-year period from 1991

through 1993. Further, the Colorado Air Pollution Control Division

(APCD) provided additional air quality data for the same time period

supporting DRCOG's position that there were no violations.

II. Analysis of the DRCOG Petition for a NOX Exemption

EPA believes that DRCOG has demonstrated that the Denver

metropolitan area qualifies for an exemption from the NOX

conformity requirements based on the ambient data provided by DRCOG and

APCD for 1991, 1992, and 1993. The AIRS data show no violations of

ozone NAAQS during these three years.

The APCD has endorsed the DRCOG petition in a letter dated December

15, 1994, from Tom Getz, Director, APCD, to Mr. William Yellowtail, the

EPA Region VIII Regional Administrator.

III. Analysis of Other Ozone Network Issues

EPA considered the condition of the ozone ambient air monitoring

network as part of evaluating the DRCOG NOX exemption request. In

1989, EPA called attention to suspected deficiencies in the ozone

ambient air monitoring network. EPA and the APCD have continued to

address these concerns over the years. The APCD conducted studies of

the ozone network in 1991 and 1992. A 1993 study report noted that the

network was not measuring at maximum concentrations. The APCD found

that the maximum concentration area covered the northwest and southwest

parts of the ozone nonattainment area. The state is required to

designate at least one site, but should include as many as are

necessary, to adequately monitor the maximum concentration area. (40

CFR Part 58).

In 1993, it was determined that higher values appeared in the

northwest part of [[Page 15270]] the maximum concentration area rather

than in the southwest. Priority was given to placing new sites in the

northwest.

In 1993, APCD added two new sites in the northwest--Enrel and South

Boulder Creek. No violations were recorded at these two sites in 1993.

However, data in AIRS show one exceedance at the South Boulder Creek

site in 1993. Three exceedances must occur for there to be a violation.

These two new sites were retained and studied in 1994. The APCD has

reported that no violations or exceedances occurred at either of these

sites in 1994.

There are nine sites currently on the Denver ozone ambient air

monitoring network, including the two new sites. The Enrel and South

Boulder Creek sites continue to record higher values than other sites

on the network. The one exceedance at the South Boulder Creek site in

1993 and the continued higher value readings at the same site and at

the Enrel site confirm study findings that these sites are within the

maximum concentration area and should remain in place.

Modifying the network to ensure monitoring of maximum

concentrations is an EPA priority and is required by 40 CFR part 58.

The EPA is working with APCD to ensure that at least one monitoring

site is established in the southwest area in 1995. In addition, the

APCD plans to conduct further study in this southwest area during the

1995 summer ozone season to more accurately identify where sites should

be placed.

Although there have been concerns with the monitoring network, EPA

believes that many of the concerns have been corrected and that any

remaining concerns are not significant enough to deny the NOX

waiver. As indicated above, no violations have been recorded by the

network, even since installation of the Enrel and South Boulder Creek

sites in 1993. In addition, the NOX waiver policy published in the

General Preamble provides further protection by providing for granting

a NOX exemption on a contingent basis as described in section IV

of this Federal Register document. This allows EPA to revoke the

exemption if violations are recorded at any monitoring sites.

IV. Approval of the NOX Exemption on a Contingent Basis

According to the General Preamble, approval of an exemption based

solely on ambient air quality monitoring data shall be granted on a

contingent basis, i.e., the exemptions will last for only as long as

the area's monitoring data continue to demonstrate attainment. If EPA

subsequently determines that the area has violated the ozone standard,

the exemption, as of the date of the determination, will no longer

apply. If a violation of the ozone NAAQS is monitored in the Denver

Metropolitan Area, EPA will provide notice in the Federal Register.

Existing transportation plans and TIPs and past conformity

determinations will not be affected by a determination that the

NOX exemption no longer applies, but new conformity determinations

would have to observe the NOX requirements of the conformity rule.

The State must continue to operate an appropriate ambient air quality

monitoring network, in accordance with 40 CFR Part 58, to verify the

attainment status of the area. The air quality data relied on for the

above determination must be consistent with 40 CFR part 58 requirements

and other relevant EPA guidance, and recorded in EPA's AIRS national

database.

The EPA NOX exemption guidelines, published in the General

Preamble, do not require that a redesignation request be submitted with

a request for a NOX transportation conformity exemption.

Conditional exemptions from the transportation conformity NOX

requirements do not substitute for the redesignation process.

The General Preamble stated that for areas which are relying on

monitoring data for the exemption request, the notice proposing

approval of the exemption request should provide opportunity for

comment on the preliminary interpretations contained in the General

Preamble. It should also offer opportunity for comment on the

appropriateness of using monitoring data which are consistent with the

requirements in 40 CFR part 58 and are recorded in AIRS as the basis of

EPA's approval and rescission of the contingent NOX exemption.

Accordingly, EPA requests comments regarding these matters.

V. Impacts of Granting a NOX Waiver for Denver Metropolitan

Area

In ozone nonattainment areas classified as transitional, such as

the Denver metropolitan area, the effect of a NOX exemption is

limited solely to the issue of whether such areas may be exempted from

meeting the applicable NOX requirements of the transportation and

general conformity rule.

EPA also stated in the General Preamble that it plans to amend the

transportation conformity rule to require that once an area's

maintenance plan is approved, any previously approved NOX

conformity exemption no longer applies. The area must then demonstrate

as part of its conformity determinations that the transportation plan

and TIP are consistent with the motor vehicle emissions budgets for

NOX where such a budget is established by the maintenance plan. As

currently written, none of the transportation conformity rule's

NOX requirements would ever apply to an area once such an area had

received a NOX transportation conformity exemption.

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.

This proposal does not create any new requirements. Therefore, I

certify that it does not have significant impact on any small entities

affected. Moreover, due to the nature of the federal-state relationship

under the CAA, preparation of a regulatory flexibility analysis would

constitute federal inquiry into the economic reasonableness of state

action.

The OMB has exempted these actions from review under Executive

Order 12866.

Interested parties are invited to comment on all aspects of this

proposed action.

List of Subjects in 40 CFR Part 52

Environmental protection, Air pollution control, Carbon Monoxide,

Hydrocarbons, Intergovernmental relations, Lead, Nitrogen dioxide,

Ozone, Particulate matter, Reporting and recordkeeping requirements,

Volatile organic compounds.

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

Dated: March 10, 1995.

William P. Yellowtail,

Regional Administrator.

[FR Doc. 95-6926 Filed 3-22-95; 8:45 am]

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