Approval and Promulgation of Implementation Plans and Designation of Areas for Air Quality Planning Purposes: State of Michigan

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[M118-01-5767, M121-01-6241; AMS-FRL-5014-8]

Approval and Promulgation of Implementation Plans and Designation

of Areas for Air Quality Planning Purposes: State of Michigan

AGENCY: Environmental Protection Agency (USEPA).

ACTION: Proposed rule.

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SUMMARY: The USEPA proposes to approve revisions to the Michigan State

Implementation Plan (SIP) for attainment and maintenance of the

National Ambient Air Quality Standard (NAAQS) for ozone. These

revisions pertain to the Detroit-Ann Arbor moderate ozone nonattainment

area which includes the following counties: Livingston, Macomb, Monroe,

Oakland, Saint Clair, Washtenaw, and Wayne. The revisions being

proposed for approval are the 1990 base year emission inventory, basic

vehicle inspection and maintenance (I/M), and redesignation of the

Detroit-Ann Arbor area to attainment for ozone and corresponding 175A

maintenance plan.

DATES: Comments on these proposed actions must be received in writing

by August 22, 1994 and will be considered before taking final action on

these SIP revisions.

ADDRESSES: Written comments should be sent to Carlton T. Nash, Chief,

Regulation Development Section, Air Toxics and Radiation Branch (AT-

18J), United States Environmental Protection Agency, Region 5, 77 West

Jackson Boulevard, Chicago, Illinois, 60604. Copies of these SIP

revisions and USEPA's analyses are available for inspection at the

above address.

FOR FURTHER INFORMATION CONTACT: Jacqueline Nwia, Environmental

Engineer, Regulation Development Section, Air Toxics and Radiation

Branch (AT-18J), United States Environmental Protection Agency, Region

5, 77 West Jackson Boulevard, Chicago, Illinois 60604, (312) 886-6081.

Anyone wishing to come to Region 5 offices should contact Jacqueline

Nwia first.

SUPPLEMENTARY INFORMATION: This document contains a number of

submittals for which the USEPA is proposing action. For purposes of

clarity, the following Table of Contents is provided as a guide for

this action.

Table of Contents

A. 1990 Base Year Emission Inventory

I. Background

II. Review of the State Submittal

III. Proposed Action

B. Inspection and Maintenance

I. Background and Review Criteria

II. Finding of USEPA Review

III. Proposed Action

C. Redesignation

I. Background

II. Evaluation Criteria

III. Review of State Submittal

1. Attainment of the Ozone NAAQS

2. Meeting Applicable Requirements of Section 110 and Part D

(A) Section 110 Requirements

(B) Part D Requirements

(B1) Subpart 1 of Part D--Section 172(c) Provisions

(B2) Subpart 1 of Part D--Section 176 Conformity Provisions

(B3) Subpart 2 Requirements

3. Fully Approved SIP Under Section 110(k) of the Act.

4. Improvement in Air Quality Due to Permanent and Enforceable

Measures.

5. Fully Approved Maintenance Plan Under Section 175A.

(A) Emissions Inventory--Base Year Inventory

(B) Demonstration of Maintenance--Projected Inventories

(C) Verification of Continued Attainment

(D) Contingency Plan

(E) Subsequent Maintenance Plan Revisions

IV. Proposed Action

D. Procedural Background

E. Regulatory Process

A. Emissions Inventory

The inventory was submitted by the State to satisfy certain Federal

requirements for an approvable nonattainment area ozone SIP for the

Detroit/Ann Arbor area in Michigan.

A detailed analysis of Michigan's 1990 Base Year Emission Inventory

SIP submittal is contained in the USEPA's technical support document

(TSD), dated January 27, 1994 from Jeanette Marrero to the Docket,

entitled ``TSD for Proposed Revision to Michigan's Ozone SIP for the

1990 Base Year Emissions Inventory for Areas Designated Nonattainment

for Ozone'' (Emission Inventory TSD), which is available from the

Region 5 office listed above.

I. Background

Under the Act, States have the responsibility to inventory

emissions contributing to NAAQS nonattainment, to track these emissions

over time, and to ensure that control strategies are being implemented

that reduce emissions and move areas towards attainment. The Act

requires ozone nonattainment areas designated as moderate, serious,

severe, and extreme to submit a plan within 3 years of 1990 to reduce

volatile organic compounds (VOC) emissions by 15 percent within 6 years

after 1990. The baseline level of emissions, from which the 15 percent

reduction is calculated, is determined by adjusting the base year

inventory to exclude biogenic emissions and certain emission reductions

not creditable towards the 15 percent. The 1990 base year emissions

inventory is the primary inventory from which the periodic inventory,

the reasonable further progress (RFP) projection inventory, and the

modeling inventory are derived. Further information on these

inventories and their purpose can be found in the ``Emission Inventory

Requirements for Ozone SIP,'' USEPA, Office of Air Quality Planning and

Standards (OAQPS), Research Triangle Park, North Carolina, March 1991.

The base year inventory may also serve as part of statewide inventories

for purposes of regional modeling in transport areas. The base year

inventory plays an important role in modeling demonstrations for areas

classified as moderate and above outside transport regions.

The air quality planning requirements for marginal to extreme ozone

nonattainment areas are set out in section 182(a)-(e) of title I of the

Act. Further, the USEPA has issued a General Preamble describing

USEPA's preliminary views on how USEPA intends to review SIP revisions

submitted under title I of the Act, including requirements for the

preparation of the 1990 base year inventory (57 FR 13502, April 16,

1992 and 57 FR 18070, April 28, 1992). Because USEPA is describing its

interpretations here only in broad terms, the reader should refer to

the General Preamble for a more detailed discussion of the

interpretations of title I advanced in this proposal and the supporting

rationale. In this rulemaking action on the Michigan ozone base year

emissions inventory, USEPA is proposing to apply its interpretations

taking into consideration the specific factual issues presented. Thus,

USEPA will consider any comments submitted within the comment period

before taking final action on this proposal.

Those States containing ozone nonattainment areas classified as

marginal to extreme are required under section 182(a)(1) of the Act to

submit a final, comprehensive, accurate, and current inventory of

actual ozone season, weekday emissions from all sources within 2 years

of enactment (November 15, 1992). This inventory is for calendar year

1990 and is denoted as the base year inventory. It includes both

anthropogenic and biogenic sources of volatile organic compounds (VOC),

nitrogen oxides (NOX), and carbon monoxide (CO). The inventory is

to address actual VOC, NOX, and CO emissions for the area during

peak ozone season, which is generally comprised of the summer months.

All stationary point and area sources, as well as highway mobile

sources within the nonattainment area, are to be included in the

compilation. Available guidance for preparing emission inventories is

provided in the General Preamble (57 FR 13498, April 16, 1992).

The inventory was submitted by the State to USEPA on January 5,

1993 as a proposed revision to the SIP. The State of Michigan held a

public hearing on August 2, 1993 to receive public comment on the 1990

base year emission inventory for Detroit/Ann Arbor nonattainment areas

and certified the hearing to the USEPA in a submittal on November 15,

1993. Supplemental information was also submitted on November 29, 1993.

The emission inventory was reviewed by USEPA to determine

completeness shortly after its submittal, in accordance with the

completeness criteria set out at 40 Code of Federal Regulations (CFR)

part 51, appendix V, as amended by 57 FR 42216 (August 26, 1991). The

submittal was found to be complete on March 16, 1993 with the exception

of evidence of a public hearing. After receiving evidence of the public

hearing, a letter from David Kee, Director, Air and Radiation Division,

USEPA, Region 5, dated January 7, 1994 was sent to the Governor's

designee indicating the completeness of the submittal and the next

steps to be taken in the review process.

II. Review of State Submittal

When reviewing the final inventory, USEPA used the Level I, II, and

III, ozone nonattainment inventory quality review checklists provided

by the OAQPS to determine the acceptance and approvability of the final

emission inventory.

Level I is essentially the initial level of broad review that USEPA

performs in order to determine if the inventory preparation guidance

requirements found in the report ``Emission Inventory Requirements for

Ozone SIPs'' (EPA-450/4-91-011) have been met. The Level II review

addresses completeness, procedures and consistency for each of the four

general source types in the inventory: stationary point and area

sources, highway mobile sources, and non-highway mobile sources. The

data quality is also evaluated. Detailed Level I and II review

procedures can be found in the following document: ``Quality Review

Guidelines for 1990 Base Year Emission Inventories,'' USEPA, OAQPS,

Research Triangle Park, NC, July 27, 1992.

Level III review procedures are specified in a memorandum from J.

David Mobley, Chief, Emissions Inventory Branch, and G. T. Helms,

Chief, Ozone/CO Programs Branch, to Air Branch Chiefs, Region I-X,

``1990 Ozone/CO SIP Emission Inventory Level III Acceptance Criteria,''

October 7, 1992 and revised in a memorandum from John Seitz, Director,

OAQPS, to Regional Air Division Directors, Region I-X, ``Emission

Inventory Issues,'' June 24, 1993. The Level III review process is

outlined here and consists of 10 points that the inventory must

include. For a base year emission inventory to be acceptable it must

pass all of the following acceptance criteria:

1. An approved Inventory Preparation Plan (IPP) was provided and

the Quality Assurance program contained in the IPP was performed and

its implementation documented.

2. Adequate documentation was provided that enabled the reviewer to

determine the emission estimation procedures and the data sources used

to develop the inventory.

3. The point source inventory must be complete.

4. Point source emissions must have been prepared or calculated

according to the current USEPA guidance.

5. The area source inventory must be complete.

6. The area source emissions must have been prepared or calculated

according to the current USEPA guidance.

7. Biogenic emissions must have been prepared according to current

USEPA guidance or another approved technique.

8. The method (e.g., Highway Performance Monitoring System or a

network transportation planning model) used to develop Vehicle Miles

Traveled (VMT)\1\ estimates must follow USEPA guidance, which is

detailed in the document, ``Procedures for Emission Inventory

Preparation, volume IV: Mobile Sources,'' USEPA, Office of Mobile

Sources and OAQPS, Ann Arbor, Michigan, and Research Triangle Park,

North Carolina, December 1992. The VMT development methods were

adequately described and documented in the inventory report.

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\1\VMT is the number of miles traveled by vehicles of various

types, preferably for each link of the highway system. The VMT is

estimated using various models and/or methods.

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9. The MOBILE model was correctly used to produce emission factors

for each of the vehicle classes.

10. Non-road mobile emissions were prepared according to current

USEPA guidance for all of the source categories.

The base year emission inventory will be approved if it passes

Levels I, II, and III of the review process.

The USEPA reviewed the State submittal using the Level I, II and

III criteria noted above. These findings are discussed further in the

Emission Inventory TSD.

III. Proposed Action

The USEPA is proposing to fully approve the ozone emission

inventory SIP submitted to USEPA for the Detroit/Ann Arbor area as

meeting the section 182(a)(1) requirements of the Act for emission

inventories. The State has submitted a complete inventory containing

point, area, biogenic, on-road, and non-road mobile source data, and

accompanying documentation. Emissions from these groupings of sources

are presented in the following tables:

Daily VOC Emissions From All Sources--Tons/Summer Weekday

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On-road Non-road

Point Area source mobile mobile Biogenic Total

Ozone nonattainment area source emissions source source emissions emissions

emissions emissions emissions

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Detroit/Ann Arbor................. 167.08 252.27 327.00 531.03 113.90 1391.28

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Daily CO Emissions From All Sources--Tons/Summer Weekday

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On-road Non-road

Point Area source mobile mobile Total

Ozone nonattainment area source emissions source source emissions

emissions emissions emissions

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Detroit/Ann Arbor.............................. 146.28 45.22 3058.00 862.54 4112.04

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Daily NOX Emissions From All Sources--Tons/Summer Weekday

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On-road Non-road

Point Area source mobile mobile Total

Ozone nonattainment area source emissions source source emissions

emissions emissions emissions

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Detroit/Ann Arbor.............................. 734.62 56.36 437.00 108.22 1336.20

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Detailed information on how each of the above source category

groupings was determined is included in the Emission Inventory TSD.

B. Inspection and Maintenance

A detailed analysis of the Michigan I/M SIP submittal is contained

in the USEPA's TSD, dated February 1, 1994 from Brad Beeson to the

Docket, entitled ``Technical Review of the Michigan SIP Submittal to

Revise the I/M Program in Southeast Michigan'' (I/M TSD), which is

available from the Region 5 office listed above.

I. Background and Review Criteria

The Act requires States to make changes to improve existing I/M

programs or implement new ones. Section 182(a)(2)(B)(i) requires States

to submit SIP revisions for any ozone nonattainment area which has been

classified as marginal, pursuant to section 181(a) of the Act, with an

existing I/M program that was part of a SIP prior to enactment of the

Act, or any area that was required by the Clean Air Act, as amended in

1977 (1977 Act) to have an I/M program, to bring the program up to the

level required in pre-1990 USEPA guidance, or to what had been

committed to previously in the SIP, whichever was more stringent. Areas

classified as moderate and worse ozone nonattainment areas were also

subject to this requirement to improve programs to this level.

On November 15, 1993 the Michigan Department of Natural Resources

(MDNR) submitted to the USEPA a revision to the Michigan SIP which was

intended to address the requirements for an I/M program in the Detroit-

Ann Arbor area. The revision included legislation which was signed into

law by Governor Engler on November 13, 1993.2

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\2\In addition to legislation revising the I/M program in the

Detroit-Ann Arbor area, the State also submitted adopted legislation

establishing an I/M program on the west side of the State. For

reasons of clarity, however, that program will be the subject of a

future Federal Register notice. Today's rulemaking only addresses

the State's submittal related to the program in the Detroit-Ann

Arbor area.

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At the same time as this legislation was being developed, the MDNR

was also in the process of developing a redesignation request from

nonattainment to attainment for the Detroit-Ann Arbor moderate ozone

nonattainment area.

Section 107(d)(3)(E) of the Act states that an area can be

redesignated to attainment if certain conditions are met. One of these

conditions is that the USEPA has fully approved the applicable

implementation plan under section 110(k) and that the State has met all

applicable requirements of section 110 and part D. The USEPA's current

approvability criteria for I/M in part require fully adopted rules for

all aspects of the proposed SIP revision. In addition, all SIPs

submitted must be subject to public hearing before they can be

approved.

On November 5, 1992 (57 FR 52950), the USEPA published a final rule

(I/M Rule) establishing I/M requirements pursuant to section 182. On

June 28, 1994 the USEPA published a proposal to amend requirements

pertaining to SIP submissions for areas required to implement a basic

I/M program that submit, and otherwise qualify for approval of, a

redesignation request (``Proposed I/M Redesignation Rule''). The

authority for that amendment is discussed in that proposal.

The I/M Redesignation Rule proposes to allow areas that have

requested redesignation to attainment, and are otherwise eligible to

obtain approval of the request, to defer adoption and implementation of

otherwise applicable requirements established in the originally

promulgated I/M rule. For such areas, the USEPA does not believe it is

necessary to revise or adopt new regulations which are not essential

for clean air, and which would not be implemented after redesignation

occurred because they are not necessary for maintenance. The proposed

rule applies only to areas that by virtue of their air quality

classification are required to implement a basic I/M program and that

submit and obtain approval of a redesignation request.

For such areas, the I/M Redesignation Rule proposes that the I/M

component of the I/M SIP contain the following four criteria:

(1) Legislative authority for basic I/M meeting all the

requirements of subpart S such that implementing regulations can be

adopted without any further legislative action,

(2) A provision in the SIP providing that basic I/M be placed in

the contingency measures portion of the maintenance plan upon

redesignation,

(3) a contingency measure consisting of a commitment by the

Governor or his/her designee to adopt regulations to implement the I/M

program in response to a specified triggering event, and

(4) a commitment that includes an enforceable schedule for the

adoption and implementation of a basic I/M program including

appropriate milestones in the event the contingency measure is

triggered.

In this rulemaking, the USEPA is considering Michigan's I/M

submittal based on the proposed I/M requirements for areas otherwise

eligible for redesignation. If the State's redesignation request is not

otherwise eligible for approval at the time the USEPA takes final

action on it, or if the proposed I/M requirements for redesignation are

not codified, Michigan's submittal will be judged by the current I/M

approvability criteria as detailed in the USEPA's final I/M rule

promulgated on November 5, 1992.

As discussed in the Proposed I/M Redesignation Rule, while the

USEPA considers the redesignation request, the State continues to be

required to meet all the current SIP submission requirements including

fully adopted rules and specific implementation deadlines as required

under 40 CFR Sec. 51.372 of the I/M Rule. If the State does not comply

with these requirements, it could be subject to sanctions pursuant to

section 179. If the redesignation request is approved, any sanctions

already imposed or any sanctions clock already triggered would be

terminated.

II. Finding of USEPA Review

On November 15, 1993 the State submitted a redesignation request

including I/M as a contingency measure for the Detroit-Ann Arbor area

to the USEPA.

Using the proposed I/M Redesignation Rule criteria for areas

redesignating from nonattainment to attainment, Michigan's I/M SIP

submittal for the Detroit-Ann Arbor area is acceptable. The State held

public hearings on the State's submittal February 14, 1994 in Detroit,

Michigan.

With respect to the first element of the four criteria, the

proposed I/M Redesignation Rule requires ``legislative authority for

basic I/M such that implementing regulations can be adopted without any

further legislative action.'' The legislation adopted by Michigan as a

whole includes all the essential elements of a satisfactory basic I/M

program. The essential elements include:

Describing the network type (``test and repair'').3

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\3\The parenthetical information refers to the specifics in the

Detroit-Ann Arbor, Michigan legislation.

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Listing of geographic coverage of program (Wayne, Oakland,

Macomb, and possibly Washtenaw if redesignated, or Wayne, Oakland,

Macomb, Washtenaw, St. Clair, Livingston, and Monroe if not

redesignated).

Specifying the test type and procedure (idle test with BAR

90 equipment).

Listing of other applicable testing procedures (visual

tampering inspection).

Defining subject vehicle population (1975 and later).

Specifying testing frequency (every 12 months).

Granting authority to a State agency to develop necessary

rules (MDNR).

Establishing the enforceable obligation in the rule

(persons shall not drive a motor vehicle without a valid emissions

certificate of compliance or waiver).

In addition to defining the elements essential to the definition of

an I/M program, the legislation grants the authority to MDNR to develop

the rest of the language necessary to make the program complete,

including technical and administrative details. No further legislative

action is necessary to authorize or implement the program.

In the event of redesignation, the USEPA believes that the States's

approach to implement I/M in the counties of Wayne, Oakland, Macomb,

and Washtenaw counties is acceptable and meets the population

requirements (geographic coverage) specified in the I/M rule (40 CFR

51.350).

Because the State has authorized and provided the essentials of an

I/M program in its adopted legislation, the first element of the

criteria proposed in the I/M Redesignation Rule is satisfied.

The second element of the I/M Redesignation Rule proposes to

require ``a provision in the SIP providing that basic I/M be placed in

the contingency measures portion of the maintenance plan upon

redesignation.'' This requirement is satisfied by the provision of

section 8(2)(a) which requires a basic I/M program to be implemented as

a contingency measure.

The third and fourth elements of the proposed I/M Redesignation

Rule require an enforceable schedule and commitment by the Governor or

his/her designee for the adoption and implementation of a basic I/M

program upon a specified, appropriate triggering event. These elements

are satisfied based on language submitted to the USEPA on November 15,

1993 under separate cover, within the State's redesignation

application. Section 6.8.3 of the State's Southeast Michigan

Redesignation TSD states ``implementation of the contingency measure[s]

will be completed in a time-frame consistent with schedules of

implementation required for SIPs under title I of the Act and

corresponding regulations.'' This commitment was submitted to the USEPA

on November 15, 1993 under the signature of Roland Harmes, the

Governor's designee. The USEPA assumes that the effective date of the

basic I/M legislation as a contingency measure is the date that the

State determines that a basic I/M program is necessary, as shown by the

urban airshed model (UAM), to correct a violation of the ozone NAAQS.

The USEPA further assumes that the basic I/M program will be

implemented in the Detroit-Ann Arbor area as a contingency measure 1

year from the effective date of the legislation as stipulated in the I/

M rule 40 CFR 51.373(b).4

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\4\Title 40 CFR 51.373(b) specifies the implementation of a

basic I/M program within 1 year of obtaining legal authority.

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While the USEPA is proposing approval of the State's I/M submittal

based on the criteria proposed in the I/M Redesignation Rule, if the

State's redesignation request is not approved, or if the alternative

approval criteria applicable to redesignation is not codified as

proposed, the State's submittal must be judged against the current I/M

approvability criteria which require fully adopted rules for all

aspects of the program, as detailed in USEPA's final I/M rule of

promulgated on November 5, 1992. The State's submittal would then not

be approvable because the submittal does not include detailed rules,

including cut points, test procedures and standards, quality control

procedures, waiver provisions, and program compliance and oversight.

III. Proposed Action

Because the State's submittal meets the I/M approvability criteria

for areas redesignating from nonattainment to attainment, USEPA is

proposing to approve the I/M plan for the Detroit-Ann Arbor area that

was submitted as a revision to the Michigan SIP. Alternatively, USEPA

is proposing to disapprove the State's I/M SIP for the Detroit-Ann

Arbor area if the State's redesignation request is ultimately not

approved or if the I/M Redesignation Rule is not codified as proposed

in USEPA's I/M rule before the USEPA finalizes its approval of the

redesignation.

C. Redesignation

Under the Act, nonattainment areas can be redesignated to

attainment if sufficient data are available to warrant such changes and

the area satisfies other criteria contained in section 107(d)(3) of the

Act. On November 12, 1993 the State submitted a redesignation request

and section 175A maintenance plan. If approved, the section 175A

maintenance plan would become a federally enforceable part of the SIP

for the Detroit-Ann Arbor area.

A detailed analysis of the Michigan Redesignation Request and

section 175A Maintenance Plan SIP submittal for the Detroit-Ann Arbor

area is contained in the USEPA's TSD, dated February 24, 1994 from

Jacqueline Nwia to the Docket, entitled ``TSD for the Request to

Redesignate the Detroit/Ann Arbor, Michigan Moderate Nonattainment Area

to Attainment for Ozone and the Proposed Revision to the Michigan Ozone

SIP for a 175A Maintenance Plan'' and ``Amendments to the February 24,

1994 TSD for the Request to Redesignate the Detroit/Ann Arbor, Michigan

Moderate Nonattainment Area to Attainment for Ozone and the Proposed

Revision to the Michigan Ozone SIP for a 175A Maintenance Plan,'' dated

June 21, 1994 (Redesignation/Maintenance Plan TSD), which are available

from the Region 5 office listed above.

I. Background

The 1977 Act required areas that were designated nonattainment

based on a failure to meet the ozone NAAQS, to develop SIPs with

sufficient control measures to expeditiously attain and maintain the

standard. The Detroit-Ann Arbor area was designated under section 107

of the 1977 Act as nonattainment with respect to the ozone NAAQS (43 FR

8962, March 3, 1978 and 43 FR 45993, October 5, 1978).

After enactment of the amended Act on November 15, 1990 the

nonattainment designation of the Detroit-Ann Arbor area continued by

operation of law according to section 107(d)(1)(C)(i) of the Act;

furthermore, it was classified by operation of law as moderate for

ozone pursuant to section 181(a)(1) (56 FR 56694, November 6, 1991 and

57 FR 56762, November 30, 1992), codified at 40 CFR 81.323.

The Detroit-Ann Arbor area more recently has ambient monitoring

data that show no violations of the ozone NAAQS, during the period from

1991 through 1993. The area, therefore, became eligible for

redesignation from nonattainment to attainment consistent with the

amended Act, and to ensure continued attainment of the ozone standard,

Michigan also submitted an ozone maintenance SIP for the Detroit-Ann

Arbor on November 12, 1993. On November 12, 1993 Michigan requested

redesignation of the area to attainment with respect to the ozone

NAAQS. On October 22, 1993 Michigan held a public hearing on the

maintenance plan component of the redesignation request.

II. Evaluation Criteria

The 1990 Amendments revised section 107(d)(3)(E) to provide five

specific requirements that an area must meet in order to be

redesignated from nonattainment to attainment.

1. The area must have attained the applicable NAAQS;

2. The area has met all relevant requirements under section 110 and

part D of the Act;

3. The area has a fully approved SIP under section 110(k) of the

Act;

4. The air quality improvement must be permanent and enforceable;

5. The area must have a fully approved maintenance plan pursuant to

section 175A of the Act.

III. Review of State Submittal

The Michigan redesignation request for the Detroit-Ann Arbor area

will meet the five requirements of section 107(d)(3)(E), noted above,

if the VOC RACT ``fix-up,''5 and ``catch-up,''6 and major

non-CTG submittals7, the 1990 base year emission inventory, basic

I/M, and the section 182(f) NOX exemption petition are also fully

approved by the USEPA.8 Because the maintenance plan is a critical

element of the redesignation request, USEPA will discuss its evaluation

of the maintenance plan under its analysis of the redesignation

request. USEPA's Redesignation/Maintenance Plan TSD contains a more in-

depth analysis of the submittal with respect to certain of these

evaluation criteria.

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\5\Section 182(b)(2) of the Act requires that moderate and above

ozone nonattainment areas adopt RACT rules for three types of

sources or source categories, i.e. RACT for source categories

covered by the CTGs and for major sources that are not subject to a

CTG, regardless of time of nonattainment designation.

\6\Section 182(a)(2)(A) of the Act requires that ozone

nonattainment areas submit rules and corrections to existing VOC

rules that were required under the section 172(b)(3) RACT provision

of the pre-amended Act (and related guidance).

\7\Rules for major non-CTG sources are a requirement under the

Section 182(b)(2) catch-ups.

\8\The emission statement program was fully approved in a final

rulemaking action on March 8, 1994 (59 FR 10752).

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1. Attainment of the ozone NAAQS

The Michigan request is based on an analysis of quality-assured

ozone air quality data which is relevant to the maintenance plan and to

the redesignation request. Ambient air ozone monitoring data for

calendar year 1991 through calendar year 19939 show an expected

exceedance rate for the ozone standard of less than 1.0 per year of the

ozone NAAQS in the Detroit-Ann Arbor area (40 CFR 50.9 and appendix H).

Because the Detroit-Ann Arbor area has complete quality-assured data

showing no violations of the standard over the most recent consecutive

three calendar year period, the Detroit-Ann Arbor area has met the

first statutory criterion of attainment of the ozone NAAQS. The State

committed to continue monitoring in this area in accordance with 40 CFR

part 58. (If, however, complete quality assured data shows violations

of the ozone NAAQS before the final USEPA action on this redesignation,

the USEPA proposes that it disapprove the redesignation request.)

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\9\The redesignation request documentation presents 1990-1992

ambient air quality monitoring data demonstrating that the Detroit-

Ann Arbor area attained the ozone NAAQS. In order to submit the

redesignation request before November 15, 1993, Michigan prepared

most of this documentation during the 1993 ozone season, when the

1993 ozone data was not available. However, the USEPA reviewed the

ambient monitoring data for 1993 contained in AIRS which

demonstrates that the area continues to attain the ozone NAAQS.

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2. Meeting Applicable Requirements of Section 110 and Part D

On May 6, 1980 (45 FR 29801) and February 7, 1985 (50 FR 5250),

USEPA fully approved Michigan's SIP for the Detroit-Ann Arbor area as

meeting the requirements of section 110(a)(2) and part D of the 1977

Act with the exception that Michigan must meet the part D RACT

requirements for the ozone SIP. The 1990 Act, however, modified section

110(a)(2) and, under part D, revised section 172 and added new

requirements for all nonattainment areas. Therefore, for purposes of

redesignation, to satisfy the requirement that the SIP meet all

applicable requirements under the 1990 Act, USEPA has reviewed the SIP

to ensure that it contains all measures that were due under the amended

1990 Act prior to or at the time Michigan submitted its redesignation

request for the Detroit-Ann Arbor area. The USEPA interprets section

107(d)(3)(E)(v) to mean that for a redesignation request to be

approved, the State has met all requirements that applied to the

subject area prior to or at the time of the submission of a complete

redesignation request. Requirements of the Act that come due

subsequently, continue to be applicable to the area at those later

dates [see section 175A(c)] and, if the redesignation of the area is

disapproved, the State remains obligated to fulfill those requirements.

(A.) Section 110 Requirements. Although section 110 was amended by

the Act, the Detroit-Ann Arbor area SIP meets the requirements of

amended section 110(a)(2). A number of the requirements did not change

in substance and, therefore, USEPA believes that the pre-amendment SIP

met these requirements. As to those requirements that were amended (57

FR 27936 and 23939, June 23, 1993) many are duplicative of other

requirements of the Act. The USEPA has analyzed the SIP and determined

that it is consistent with the requirements of amended section

110(a)(2).

(B.) Part D Requirements. Before the Detroit-Ann Arbor area may be

redesignated to attainment, it must have fulfilled the applicable

requirements of part D. Under part D, an area's classification

indicates the requirements to which it will be subject. Subpart 1 of

part D sets forth the basic nonattainment requirements applicable to

all nonattainment areas, classified as well as nonclassifiable. Subpart

2 of part D establishes additional requirements for nonattainment areas

classified under table 1 of section 181(a). As described in the General

Preamble for the Implementation of title 1, specific requirements of

subpart 2 may override subpart 1's general provisions (57 FR 13501

(April 16, 1992)). The Detroit-Ann Arbor area was classified as

moderate (56 FR 56694, November 6, 1991), codified at 40 CFR 81.323.

Therefore, in order to be redesignated to attainment, the State must

meet the applicable requirements of subpart 1 of part D--specifically

sections 172(c) and 176 as well as the applicable requirements of

subpart 2 of part D.

(B1.) Subpart 1 of Part D--Section 172(c) Provisions. Section

172(c) sets forth general requirements applicable to all nonattainment

areas. Under 172(b), the section 172(c) requirements are applicable as

determined by the Administrator, but no later than 3 years after an

area has been designated as nonattainment under the amended Act. The

USEPA has not determined that these requirements are applicable to

ozone nonattainment areas on or before November 12, 1993--the date the

State submitted a complete redesignation request for the Detroit-Ann

Arbor area. Therefore, the State was not required to meet these

requirements for redesignation purposes. In addition, as discussed

below, Michigan has either satisfied the section 172(c) requirements

or, as is the case for several of them, they lose their continued force

once an area has demonstrated attainment and maintenance of the ozone

NAAQS.

(1) RFP is defined as progress that a nonattainment area must make

each year toward attainment of the ozone NAAQS. This requirement only

has relevance during the time it takes an area to attain the NAAQS.

Because the Detroit-Ann Arbor area has attained the ozone NAAQS, its

SIP has already achieved the necessary RFP toward that goal.

(2) In addition, because the Detroit-Ann Arbor has attained the

ozone NAAQS and is no longer subject to an RFP requirement, the section

172(c)(9) contingency measures are not applicable unless the

redesignation request and maintenance plan are not finally approved.

Such contingency measures must take effect if the area fails to meet an

RFP milestone or fails to attain the ozone NAAQS; the Detroit-Ann Arbor

area no longer has RFP milestones and has already attained the NAAQS.

However, section 175A contingency measures still apply.

(3) Similarly, once an area is redesignated to attainment,

nonattainment new source review (NSR) requirements are not generally

applicable. The area then becomes subject to prevention of significant

deterioration (PSD) requirements instead of the NSR program (57 FR

13564). The State has an acceptable program for review of new sources

(45 FR 29790, May 6, 1980 and 47 FR 3765, February 7, 1985). The PSD

program was delegated to the State of Michigan on September 10, 1979

and amended on November 7, 1983 and September 26, 1988. Moreover, as

discussed with respect to the NSR requirements of part D, the USEPA

believes that the applicability of the part C PSD program to

maintenance areas makes it unnecessary to require that an area have

obtained full approval of the NSR revisions required by part D in order

to be redesignated.

(4) The 172(c)(3) requirement for an emissions inventory has been

met by submission and proposed approval of the 1990 base year emission

inventory required by section 182(a)(1).

(5) No additional Reasonably Available Control Measures (RACM)

controls beyond what may already be required in the SIP are necessary

upon redesignation to attainment. The General Preamble (57 FR 13560,

April 16, 1992) explains that section 172(c)(1) requires the plans for

all nonattainment areas to provide for the implementation of all RACM

as expeditiously as practicable. The EPA interprets this requirement to

impose a duty on all nonattainment areas to consider all available

control measures and to adopt and implement such measures as are

reasonably available for implementation in the area as components of

the areas attainment demonstration. Because attainment has been

reached, no additional measures are needed to provide for attainment.

(6) For purposes of redesignation, the Michigan SIP was reviewed to

ensure that all requirements of section 110(a)(2), containing general

SIP elements, under the Act were satisfied. Title 40 CFR 52.1172

evidences that the Michigan SIP was approved under section 110 of the

Act, and further that it satisfies all part D, title I (as amended in

1977) requirements on May 6, 1980 (45 FR 29801) and February 7, 1985

(50 FR 5250) with the exception that Michigan must meet the part D RACT

requirements for the ozone SIP.

(B2.) Subpart 1 of Part D--Section 176 Conformity Provisions.

Section 176(c) of the Act requires States to revise their SIPs to

establish criteria and procedures to ensure that Federal actions,

before they are taken, conform to the air quality planning goals in the

applicable State SIP. The requirement to determine conformity applies

to transportation plans, programs and projects developed, funded or

approved under title 23 U.S.C. or the Federal Transit Act

(``transportation conformity''), as well as to all other Federal

actions (``general conformity''). Section 176 further provides that the

conformity revisions to be submitted by States must be consistent with

Federal conformity regulations that the Act required the USEPA to

promulgate. Congress provided for the State revisions to be submitted

on year after the date for promulgation of the final USEPA conformity

regulations. When that date passed without such promulgation, USEPA's

General Preamble for the implementation of title I informed States that

its conformity regulations would establish a submittal date [see 57 FR

13498, 13557 (April 16, 1992)]. The USEPA promulgated final

transportation conformity regulations on November 24, 1993 (58 FR

62188) and general conformity regulations on November 30, 1993 (58 FR

63214). These conformity rules require that States adopt both

transportation and general conformity provisions in the SIP for areas

designated nonattainment or subject to a maintenance plan approved

under section 175A of the Act. Pursuant to section 51.396 of the

transportation conformity rule and section 51.851 of the general

conformity rule, the State of Michigan is required to submit a SIP

revisions containing transportation and general conformity criteria and

procedures consistent with those established in the Federal rule by

November 25 and 30, 1994, respectively. Because the deadline for such

submittals has not yet come due, it is not an applicable requirement,

under section 107(d)(3)(E)(v), for approval of this redesignation

request.

(B3.) Subpart 2 Requirements. Detroit-Ann Arbor is a moderate ozone

nonattainment area. Under subpart 2, as of the date the State submitted

a complete redesignation request, it is required to have met the

requirements of section 182(a)(1), (2), and (3), section 182(b)(2), and

(4), and section 182(f). The State has submitted SIP revisions which

have not yet been approved by the USEPA but must be in order to find

that the State has met all the applicable requirements of the following

sections of the Act: Section 182(a)(1) 1990 base year emission

inventory, section 182(a)(2)(A) VOC RACT ``fix-ups,'' section

182(a)(2)(B) I/M fix-ups, section 182(b)(2) (``catch-ups'') VOC RACT

for each VOC source covered by a CTG issued between enactment of the

Act and the attainment date (since the due date for these rules is

November 15, 1994 which has not come due yet, it is not a requirement

for approval of this redesignation request), all VOC sources covered by

any CTG issued before the date of enactment of the Act, and all other

major stationary sources of VOC located in the area, section 182(b)(4)

basic I/M, and section 182(f) NOX requirements. Section 182(b)(3)

Stage II vapor recovery was also an applicable requirement. However,

the ``onboard rule''10 was published on April 6, 1994 and section

202(a)(6) of the Act provides that once onboard rules are promulgated,

Stage II vapor recovery will no longer be a requirement. In addition,

Michigan's emission statement program SIP submitted to satisfy the

section 182(a)(3)(B) requirement was fully approved in a final USEPA

rulemaking on March 8, 1994 (59 FR 10752). The USEPA is proposing to

approve this redesignation request notwithstanding the lack of fully-

approved provisions submitted in compliance with the NSR requirements

of part D, section 182(b)(5) of the CAA. The USEPA believes, as

suggested by the General Preamble at 57 FR 13564 (April 16, 1992), that

the applicability of the part C PSD program to maintenance areas makes

it unnecessary to require that an area have obtained full approval of

NSR revisions required by part D in order to be redesignated. The USEPA

believes that this interpretation of the Act is appropriate

notwithstanding section 175A(d)'s requirements that the contingency

provisions of a maintenance plan include a commitment on the part of

the State to implement all measures, to control the relevant air

pollutant, that were contained in the SIP prior to redesignation. The

term ``measure'' is not defined in section 175A(d) and it appears that

Congress utilized the terms ``measure'' or ``control measure''

differently in different provisions of the CAA that concern the PSD and

NSR permitting programs.

---------------------------------------------------------------------------

\10\The rule which was published by the USEPA on April 6, 1994

requires a vehicle based (onboard) system for the control of vehicle

refueling emissions. Gasoline vapors which are normally vented to

the atmosphere, are captured in a carbon canister and stored for

later use by the vehicle's engine.

---------------------------------------------------------------------------

Compare section 110(a)(2)(A) and (C) with section 161. In light of

this ambiguity in the use of the term ``measure,'' the USEPA believes

that the term ``measure'' as used in section 175A(d) may be interpreted

so as not to include NSR permitting programs. That this is an

appropriate interpretation is further supported by USEPA's historical

practice dating back even before the 1990 CAA, of not requiring

redesignating areas to demonstrate through modeling or otherwise a

justification for replacing the nonattainment NSR program with the PSD

program once an area was redesignated. Rather the USEPA has

historically allowed the NSR program to be automatically replaced by

the PSD program upon redesignation. Michigan has presented an adequate

demonstration that the State has met all the requirements applicable to

the area under section 110 and part D. The final approval of this

redesignation request is contingent on the final approval of the SIP

submittals as noted above. These requirements, their applicability and

status are discussed in more detail in the USEPA's Redesignation/

Maintenance Plan TSD.

3. Fully Approved SIP Under Section 110(k) of the Act

In other sections of this action, USEPA is proposing approval of

the 1990 base year emission inventory and basic I/M (meeting the

criteria of the June 28, 1994 proposed I/M Redesignation Rule). The SIP

submittals for satisfying the requirements for VOC RACT catch-ups, and

fix-ups are being acted upon in a separate action. The 182(f) NOX

exemption petition also is being acted upon in a separate action. Once

USEPA fully approves these submittals, the State will have a fully

approved SIP under section 110(k), which also meets the applicable

requirements of section 110 and part D as discussed above.

4. Improvement in Air Quality Due to Permanent and Enforceable Measures

Under the pre-amended Act, USEPA approved the Michigan SIP control

strategy for the Detroit-Ann Arbor nonattainment area, satisfied that

the rules and the emission reductions achieved as a result of those

rules were enforceable. Furthermore, numerous Federal measures apply to

the Detroit-Ann Arbor area. The State provided a detailed discussion of

the development of the emission reductions of ozone precursors (VOC and

NOX) from 1988-1993. The State attributed the improvement in air

quality that led to attainment of the ozone NAAQS to the federally

enforceable Federal Motor Vehicle Control Program (FMVCP) and lower

Reid Vapor Pressure (RVP)11 control measures. The emission

reductions achieved from 1988 through 1993 are 226 tons VOC (21

percent) and 45 tons of NOX (3.4 percent) per day. In association

with its emission inventory discussed below, the State demonstrated

that point source VOC emissions were not artificially low due to local

economic downturn. This was accomplished by setting all growth factors

at a minimum value of 1.0 for 1990 and beyond. The USEPA finds that the

combination of existing USEPA-approved SIP and Federal measures

contribute to the permanence and enforceability of reduction in ambient

ozone levels that have allowed the area to attain the NAAQS.

---------------------------------------------------------------------------

\1\1VOC emission reductions, in part, resulted from RVP

reductions from 11.0 psi in 1988 to 9.0 psi in 1993.

---------------------------------------------------------------------------

5. Fully Approved Maintenance Plan Under Section 175A

Section 175A of the Act sets forth the elements of a maintenance

plan for areas seeking redesignation from nonattainment to attainment.

The plan must demonstrate continued attainment of the applicable NAAQS

for at least 10 years after the Administrator approves a redesignation

to attainment. Eight years after the redesignation, the State must

submit a revised maintenance plan which demonstrates attainment for the

10 years following the initial 10-year period. To provide for the

possibility of future NAAQS violations, the maintenance plan must

contain contingency measures, with a schedule for implementation,

adequate to assure prompt correction of any air quality problems.

Section 175A(d) requires that the contingency provisions include a

requirement that the State will implement all control measures that

were contained in the SIP prior to redesignation as an attainment area.

In this action, USEPA is proposing approval of the State of Michigan's

maintenance plan for the Detroit-Ann Arbor area because USEPA finds

that Michigan's submittal meets the requirements of section 175A

provided that the State's contingency measures that were required as

SIP revisions prior to the submission of the redesignation request are

fully approved. If USEPA determines after notice and comment that it

should give final approval to the maintenance plan, the Detroit-Ann

Arbor nonattainment area will have a fully approved maintenance plan in

accordance with section 175A.

(A) Emissions Inventory--Base Year Inventory. The State has

adequately developed an attainment emission inventory for 1993 that

identifies 790 tons of VOC and 1336 tons of NOx per day as the

level of emissions in the area sufficient to attain the ozone NAAQS.

The 1993 attainment inventory was based on the comprehensive

inventories of VOC and NOX emissions from area, stationary, and

mobile sources for 1990. Consistent with emission inventory guidance,

the 1990 base year emission inventory represents 1990 average summer

day actual emissions for the Detroit-Ann Arbor area. Since the

projected 1993 emissions are lower than the actual 1990 emissions

(providing a more stringent attainment inventory) and 1993 is the

attainment year, it is appropriate to utilize projected 1993 emissions

for the attainment year inventory. Furthermore, the 1990 base year

emission inventory was prepared in accordance with USEPA guidance.

USEPA's TSDs prepared for the 1990 base year emission inventory

(Emission Inventory TSD) SIP revision and the redesignation request

(Redesignation/Maintenance Plan TSD) contain more in-depth details

regarding the emission inventories for the Detroit-Ann Arbor area.

The 1990 base year emission inventory also served as the basis for

calculations to demonstrate maintenance by projecting emissions forward

to the years 1993, 1996, 2000, and 2005. Projections are based on

growth factors extracted from the Southeast Michigan Council of

Governments Regional Development Forecast (RDF). Supplemental

information used in the development of emission projections include

source-specific data for electric utilities, automobile manufacturing,

aircraft, and gasoline marketing.

Growth factors are derived from employment forecasts by two-digit

Source Industrial Code by county. In addition, product output data was

used to develop growth factors for motor vehicle manufacturing, and

utilities. The area source growth factors used from RDF were based on

population or housing data. Furthermore, all growth factors that were

less than 1.0 were set equal to 1.0 for 1990 and beyond to offset any

effects of negative growth possibly due to economic downturns.

In developing the mobile source emission estimates, the MOBILE5a

model was used. The significant input parameters for the MOBILE5a model

are analyzed in detail in the Redesignation/Maintenance Plan TSD.

The stationary source emission estimates (point and area) were

developed using the geocoded emissions modeling and projections system

(GEMAP). This emission projection model and supporting documentation

were reviewed by Region 5 and the Emission Inventory Branch of the

OAQPS during the developmental stages of the redesignation request and

appear to be acceptable since GEMAP employs methodologies equivalent to

the applicable USEPA guidance on emission projections (June 21, 1993

letter to John Schroeder and August 3, 1993 Record of Conversation with

OAQPS, RADIAN and Region 5).

(B.) Demonstration of Maintenance--Projected Inventories. In order

to demonstrate continued attainment, the State projected anthropogenic

1990 actual emissions of VOC and NOX emissions to the years 1993,

1996, 2000, and 2005. These emission estimates are presented in the

tables below and demonstrate that the VOC and NOX emissions will

remain below the attainment year emissions (1993). In fact, the

emissions projections through the year 2005 show that emissions will be

reduced from 1993 levels by 21 tons of VOC and 98 tons of NOX per

day by 2005. These emission reductions are primarily the result of the

implementation of FMVCP. It is noted that the emission projections are

conservative since they do not account for emission reductions that

will result from the anticipated implementation of other control

measures and programs during this time period.

VOC Emission Inventory Summary (Tons Per Day)

------------------------------------------------------------------------

1990 1993 1996 2000 2005

------------------------------------------------------------------------

Point...................... 153 154 155 156 157

Area....................... 377 382 390 402 416

Mobile..................... 326 254 234 214 196

--------------------------------------------

Total................ 856 790 779 772 769

------------------------------------------------------------------------

NOX Emission Inventory Summary (Tons Per Day)

------------------------------------------------------------------------

1990 1993 1996 2000 2005

------------------------------------------------------------------------

Point...................... 711 735 756 685 725

Area....................... 195 199 203 206 210

Mobile..................... 437 402 362 326 303

--------------------------------------------

Total................ 1,343 1,336 1,321 1,217 1,238

------------------------------------------------------------------------

The emission projection methodologies used for the maintenance

demonstration are the same as those used for the attainment inventory

and discussed above.

The emission projections show that the emissions are not expected

to exceed the level of the base year 1993 inventory during the 10-year

maintenance period. Further emission reductions that will occur during

this maintenance demonstration that are not accounted for in the

emission projections presented in the tables above such as title III

maximum achievable control technology for air toxics, and onboard

refueling vapor recovery. The projected emission inventories were

prepared in accordance with USEPA guidance. Finally, USEPA's

Redesignation/Maintenance Plan TSD contains more in-depth details

regarding the projected emission inventories for the Detroit-Ann Arbor

area.

To demonstrate maintenance out to the year 2005 following

redesignation, the State did not rely on certain SIP-approved measures.

The State now requests that these measures (discussed below) be moved

from the applicable SIP into the maintenance plan as contingency

measures.

The State has demonstrated maintenance without basic I/M, Stage I

expansion12, Stage II and NOX RACT. The Act required a SIP

submittal for these control measures prior to the submittal of the

redesignation request, and consequently, they are required to be fully

adopted and fully approved into the SIP prior to or at the time of full

approval of the redesignation request. However, since the State has

demonstrated attainment and maintenance without these programs these

measures can be incorporated into the area's maintenance plan as

contingency measures (see, e.g., September 17, 1993 Shapiro

memorandum). The June 28, 1994 Proposed I/M Redesignation Rule proposes

to allow basic I/M to be included as a contingency measure in the form

of enabling legislation. Stage I must be fully adopted since it is a

SIP element that was due prior to the submittal of the redesignation

request. Stage II, however, does not have to be fully adopted. In fact,

since the ``onboard rule'' was published on April 6, 1994 Stage II is

no longer a requirement (section 202(a)(6) of the Act). However, if the

State chooses to include this program as a contingency measure,

enabling legislation would suffice. Michigan has chosen to retain Stage

II as a contingency measure in the maintenance plan. Finally, the State

submitted to USEPA a section 182(f) NOX exemption petition based

on 1991-1993 ambient air quality data that demonstrates that the area

is attaining the ozone NAAQS. The USEPA is currently taking action on

this submittal. Since the Detroit-Ann Arbor area has demonstrated that

it can maintain the standard without the implementation of these

programs, USEPA proposes that the maintenance plan be approved with

these elements as contingency measures. In addition, based on the

maintenance demonstration, the USEPA plans to propose approval of the

basic I/M enabling legislation (based on the June 28, 1994 proposed I/M

Redesignation Rule), and the Stage I rule and 182(f) NOX exemption

petition in a separate FR action.

---------------------------------------------------------------------------

\1\2The expanded applicability of Stage I to county boundaries

of each nonattainment area classified as moderate and above.

---------------------------------------------------------------------------

C. Verification of Continued Attainment

Continued attainment of the ozone NAAQS in the Detroit-Ann Arbor

area depends, in part, on the State's efforts toward tracking

indicators of continued attainment during the maintenance period. The

tracking plan for the Detroit-Ann Arbor area consists of two

components; continued ambient ozone monitoring and inventory updates.

To demonstrate ongoing compliance with the NAAQS, Michigan will

continue to monitor ozone levels throughout the area. The State will

also conduct periodic inventories for the redesignated area every 3

years using the most recent emission factors, models and methodologies.

The inventories will begin in 1996 with completion of the 1996

inventory by July 1, 1998. Periodic inventories for 1999, 2002, and

2005 will be completed with submittal to the USEPA on the first of

October 2 years after the inventory year. The periodic inventory will

consist of reviewing the assumptions of the maintenance demonstration

such as VMT, population, employment, etc. If substantial changes are

discovered, the State will reproject the emissions for the maintenance

period.

The contingency plan contains only one trigger, a monitored air

quality violation of the ozone NAAQS, as defined in 40 CFR 50.9. The

trigger date will be the date that the State certifies to the USEPA

that the air quality data are quality assured and no later than 30 days

after an ambient air quality violation is monitored.

D. Contingency Plan

The level of VOC and NOX emissions in the Detroit-Ann Arbor

area will largely determine its ability to stay in compliance with the

ozone NAAQS in the future. Despite best efforts to demonstrate

continued compliance with the NAAQS, the ambient air pollutant

concentrations may exceed or violate the NAAQS. Therefore, as required

by section 175A of the Act, Michigan has provided contingency measures

with a schedule for implementation in the event of a future ozone air

quality problem. Contingency measures contained in the plan include

basic I/M, NOX RACT, Stage I expansion, Stage II, RVP reduction to

7.8 psi and intensified RACT for degreasing operations. In instances

where the contingency measures must be actually adopted and

implemented, the schedules specified for these SIPs in the Act and any

corresponding regulations will be observed, with the exception of

implementation of 7.8 RVP and intensified degreasing rules which will

commence 12 months after the decision to employ these measures. Once

the triggering event, a violation of the ozone NAAQS, is confirmed, the

State will implement one or more appropriate contingency measure.

Selection of the contingency measure(s) will be based on a technical

analysis using UAM. The Governor will select the contingency measures

within 6 months of a triggering event. The adoption and implementation

schedules for the selected contingency measure(s) will be submitted to

the USEPA with the UAM analysis. The USEPA understands, on the basis of

the State's submission, that the adoption and implementation schedules

specified in the Act and any corresponding regulations would be

observed; therefore, the following schedules will be applicable for the

contingency measures specified in the contingency plan:

Basic I/M would be implemented as a contingency measure 1

year from the effective date of the legislation, which would be the

date of the decision to employ a basic I/M program to correct a

violation of the ozone NAAQS. Part 40 CFR 51.373(b) stipulates

implementation of basic I/M within 1 year of obtaining legal authority.

NOX RACT rules would be submitted 2 years from date

of the decision to employ NOx RACT as a contingency measure. The

NOX RACT rules would be implemented 30.5 months from the date NOx

RACT rules are submitted to the USEPA or 54.5 months from the date of

the decision to employ NOX RACT as a contingency measure. This

schedule is consistent with section 182(b)(2)(C) which is the schedule

applicable to the adoption and implementation of NOX RACT as

specified by section 182(f).

Implementation of Stage I expansion to the entire seven

county Detroit-Ann Arbor area (currently, Stage I is implemented in

Wayne, Oakland and Macomb counties) would be in accordance with the

schedule contained in Michigan's Stage I legislation (Senate Bill 726,

section 9i). Gasoline dispensing facilities of any size constructed

after November 15, 1990 must implement Stage I within 6 months of the

decision to employ Stage I as a contingency measure. Existing

facilities dispensing 100,000 gallons or more of gasoline a month must

implement Stage I within 1 year and facilities dispensing less than

100,000 gallons of gasoline a month must implement Stage I within 2

years of the decision to employ Stage I as a contingency measure.

Stage II would be implemented according to the same

schedule set forth for Stage I, since they are contained in the same

legislation (Senate Bill 726), but will only be implemented in the

counties of Wayne, Oakland, Macomb and Washtenaw.

Under separate cover, the State has submitted to the USEPA, as SIP

revisions, fully adopted legislation allowing implementation of a basic

I/M program, Stage I, and Stage II in the Detroit-Ann Arbor area. The

legislation provide for implementation of these programs as contingency

measures within areas redesignated to attainment for ozone.

The USEPA's Redesignation/Maintenance Plan TSD provides a more

detailed discussion of each contingency measure.

The USEPA finds that the five contingency measures provided in the

State submittal meet the requirements of section 175A(d) of the Act

since they would promptly correct any violation of the ozone NAAQS.

E. Subsequent Maintenance Plan Revisions

In accordance with section 175A(b) of the Act, the State has agreed

to submit a revised maintenance SIP 8 years after the area is

redesignated to attainment. Such revised SIP will provide for

maintenance for an additional 10 years.

IV. Proposed Action

The USEPA proposes to approve the Detroit-Ann Arbor ozone

maintenance plan as a SIP revision meeting the requirements of section

175A if there is full and final approval of the outstanding VOC RACT

requirements previously discussed, 1990 base year emission inventory,

basic I/M (meeting the criteria of the June 28, 1994 proposed I/M

Redesignation Rule), and the section 182(f) NOX exemption

petition. In addition, the USEPA is proposing approval of the

redesignation request for the Detroit-Ann Arbor area, subject to final

approval of the maintenance plan, because the State has demonstrated

compliance with the requirements of section 107(d)(3)(E) for

redesignation pending full approval of the SIP elements listed above.

(In the alternative, if ambient air quality violations occur before

USEPA takes final action on the proposed redesignation or if the USEPA

does not fully approve any of the SIP revisions listed above, the USEPA

proposes to disapprove this redesignation request.)

Nothing in this action should be construed as permitting or

allowing or establishing a precedent for any future request for

revision to any SIP. Each request for revision to the SIP shall be

considered separately in light of specific technical, economic, and

environmental factors and in relation to relevant statutory and

regulatory requirements.

Ozone SIPs are designed to satisfy the requirements of part D of

the Act and to provide for attainment and maintenance of the ozone

NAAQS. This proposed redesignation should not be interpreted as

authorizing the State to delete, alter, or rescind any of the VOC or

NOX emission limitations and restrictions contained in the

approved ozone SIP. Changes to ozone SIP VOC regulations rendering them

less stringent than those contained in the USEPA approved plan cannot

be made unless a revised plan for attainment and maintenance is

submitted to and approved by USEPA. Unauthorized relaxations,

deletions, and changes could result in both a finding of

nonimplementation [section 173(b) of the Act] and in a SIP deficiency

call made pursuant to section 110(a)(2)(H) of the Act.

D. Procedural Background

This action has been classified as a Table 2 Action by the Regional

Administrator under the procedures published in the Federal Register on

January 19, 1989 (54 FR 2214-2225). A revision to the SIP processing

review tables was approved by the Acting Assistant Administrator for

Office of Air and Radiation on October 4, 1993 (Michael Shapiro's

memorandum to Regional Administrators). A future action will inform the

general public of these tables. On January 6, 1989, the Office of

Management and Budget (OMB) waived Table 2 and 3 SIP revisions from the

requirement of section 3 of Executive Order 12291 for a period of 2

years (54 FR 2222). The USEPA has submitted a request for a permanent

waiver for Table 2 and Table 3 SIP revisions. OMB has agreed to

continue the waiver until such time as it rules on USEPA's request.

This request continued in effect under Executive Order 12866 which

superseded Executive order 12291 on September 30, 1993.

E. Regulatory Process

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

the USEPA must prepare a regulatory flexibility analysis assessing the

impact of any proposed or final rule on small entities. 5 U.S.C.

section 603 and 604. Alternatively, the USEPA 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.

The SIP approvals under section 110 and subchapter I, part D of the

Act do not create any new requirements, but simply approve requirements

that the State is already imposing. Therefore, because the Federal SIP

approval does not impose any new requirements, I certify that it does

not have a significant impact on any small entities affected. Moreover,

due to the nature of the Federal-State relationship under the Act,

preparation of a regulatory flexibility analysis would constitute

Federal inquiry into the economic reasonableness of State action. The

Act forbids USEPA to base its actions concerning SIP's on such grounds.

Union Electric Co. v. U.S.E.P.A., 427 U.S. 246, 256-66 (S.Ct. 1976); 42

U.S.C. section 7410(a)(2).

Under section 307(b)(1) of the Act, petitions for judicial review

of this action must be filed in the United States Court of Appeals for

the appropriate circuit by September 19, 1994. Filing a petition for

reconsideration by the Administrator of this rule does not affect the

finality of this rule for the purposes of judicial review nor does it

extend the time within which a petition for judicial review may be

filed, and shall not postpone the effectiveness of such a rule. This

action may not be challenged later in proceedings to enforce its

requirements. (section 307(b)(2).)

List of Subjects

40 CFR Part 52

Environmental protection, Air pollution control, Nitrogen oxides,

Ozone, Volatile organic compounds, Hydrocarbons, Intergovernmental

relations, Carbon monoxide, Motor vehicle pollution, Particulate

matter, Reporting and record keeping requirements.

40 CFR Part 81

Environmental protection, Air pollution control, National parks,

Wilderness areas.

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

Dated: June 24, 1994.

David A. Ullrich,

Acting Regional Administrator.

[FR Doc. 94-17556 Filed 7-20-94; 8:45 am]

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