15920 Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Part 52

[FRL–5987–8]

Promulgation of Federal

Implementation Plan for Arizona—

Phoenix Moderate Area PM–10;

Disapproval of State Implementation

Plan for Arizona—Phoenix Moderate

Area PM–10

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Proposed rulemaking and

withdrawal of 1996 proposed rule.

SUMMARY: Under the authority of section

110(c)(1) of the Clean Air Act (CAA or

‘‘the Act’’), EPA today proposes a

federal implementation plan (FIP) to

address the moderate area PM–10

requirements for the Phoenix PM–10

nonattainment area. Specifically, for

both the annual and 24-hour PM–10

standards, EPA is proposing a

demonstration that reasonably available

control measures (RACM) will be

implemented as soon as possible, a

demonstration that it is impracticable

for the area to attain the standards by

the statutory attainment deadline and a

demonstration that reasonable further

progress (RFP) is being met. Pursuant to

a court order, EPA’s final FIP must be

signed by the EPA Administrator no

later than July 18, 1998.

As part of its proposed RACM

demonstration, EPA is proposing a

fugitive dust rule to control PM–10

emissions from vacant lots, unpaved

parking lots and unpaved roads, and is

also proposing an enforceable

commitment to ensure that RACM for

agricultural sources will be proposed by

September 1999, finalized by April 2000

and implemented by June 2000.

In addition, in today’s document, EPA

is withdrawing a 1996 proposal to

restore its approval of the RACM, RFP

and impracticability demonstrations in

Arizona’s moderate area PM–10 plan for

the annual PM–10 standard for Phoenix

and is proposing to disapprove the

impracticability and RACM

demonstrations because those

demonstrations do not adequately

address the CAA’s moderate area PM–10

requirements.

EPA recently established a new

standard for PM–2.5 and also revised

the PM–10 standards; however, today’s

proposal does not address these new

standards.

DATES: Written comments will be

accepted until May 18, 1998. EPA is

scheduled to hold a public workshop

followed by a public hearing at the

following time:

Phoenix PM–10 Moderate Area FIP

Workshop and Hearing

Thursday, April 16, 1998, Workshop, 9

a.m. to 11 a.m.

Hearing, Day Session—12 noon to 4:30

p.m., Evening Session—Convenes at 7

p.m.

ADDRESSES: Written comments on the

EPA’s proposed FIP and SIP actions

must be received by EPA at the address

below on or before May 18, 1998.

Comments should be submitted (in

duplicate, if possible) to: EPA Region 9,

75 Hawthorne Street (AIR2), San

Francisco, CA 94105, Attn. Eleanor

Kaplan, (Phone: 415–744–1287).

The public workshop and public

hearing will be held at the Phoenix

Corporate Center Auditorium, 3003

North Central Avenue, Phoenix,

Arizona.

A copy of docket No. A–09–98,

containing material relevant to EPA’s

proposed action, is available for review

at: EPA Region 9, Air Division, 75

Hawthorne Street, San Francisco, CA

94105. Interested persons may make an

appointment with Eleanor Kaplan (415)

744–1159 to inspect the docket at EPA’s

San Francisco office on weekdays

between 9 a.m. and 4 p.m.

A copy of docket no. A–09–98 is also

available to review at the Arizona

Department of Environmental Quality,

Library, 3033 N. Central Avenue,

Phoenix, Arizona 85012. (602) 207–

2217.

Electronic availability: This document

is also available as an electronic file on

EPA’s Region 9 Web Page at http://

www.epa.gov/region09.

FOR FURTHER INFORMATION CONTACT: For

questions and issues regarding the

proposed measure for agricultural fields

and aprons contact John Ungvarsky

(415) 744–1286; for questions and issues

regarding the proposed rule for vacant

lots, unpaved parking lots and unpaved

roads contact Karen Irwin (415) 744–

1903; for other general FIP and SIP

questions and issues contact Doris Lo

(415) 744–1287.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Executive Summary

A. Background

B. FIP Proposal

C. Public Involvement in the FIP Process

II. Background

A. Clean Air Act Requirements

1. Designation and Classification

2. Moderate Area Planning Requirements

3. Federal Implementation Plan Provisions

4. Indian Reservations

a. EPA’s FIP Obligation

b. EPA and Tribal CAA Authority in Indian

Country

B. History of Arizona’s PM–10 Plans and

Related EPA Actions

1. Arizona’s Moderate Area PM–10 Plan

2. The Microscale Plan—the 24-hour

Standard

3. EPA Actions on Arizona’s Moderate

Area PM–10 Plan Post-Ober With

Respect to the Annual Standard

C. History of PM–10 FIP Litigation in

Phoenix

III. SIP Actions

A. Proposed Disapproval of Moderate Area

Plan

B. Withdrawal of Proposal to Restore

Moderate Area Plan Demonstrations for

the Annual PM–10 Standard

IV. Moderate Area PM–10 Planning

Requirements for the FIP Proposal

A. Attainment/Impracticability

Demonstration

B. RACM/RACT Demonstration

C. Reasonable Further Progress

Demonstration

V. Summary of EPA’s FIP Proposal

A. RACM/RACT Demonstration

1. RACT and PM–10 Precursors

a. RACT

b. PM–10 Precursors

2. RACM Approach

3. Federal Implementation Criteria

a. Applicability to the Phoenix Area

b. Existing RACM

c. Legal Authority

4. Application of Federal Implementation

Criteria

5. RACM Criteria

a. De Minimus Source

b. Technological Feasibility

c. Cost of Implementation

6. Application of RACM Criteria

7. Proposed FIP measures

a. Commitment for Agricultural Sector

(1) Summary of Proposed Commitment and

Approach

(2) Background

(3) RACM Analysis

(4) Proposed Commitment

(i) Discussions With Stakeholders

(ii) BMP Approach

(iii) FIP Proposal

(5) FIP Replacement

b. Rule for Unpaved Parking Lots, Unpaved

Roads and Vacant Lots

(1) Summary of Proposed Rule

(2) Discussion

(3) Compliance Approach

(4) Replacement of FIP Rule

B. Impracticability Demonstration

1. Annual Standard

2. 24-hour Standard

C. Reasonable Further Progress (RFP)

Demonstration

1. Annual Standard

2. 24-hour Standard

a. Gilbert Monitoring Site

b. West Chandler Monitoring Site

VI. Impact on Tribal Reservations

VII. Administrative Requirements

A. Executive Order (E.O.) 12866

B. Regulatory Flexibility Analysis

1. Regulatory Flexibility Act Requirements

2. RFA Analysis

a. Proposed Federal Rule for Unpaved

Roads, Unpaved Parking Lots, and

Vacant Lots
Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules 15921

b. Proposed Federal Commitment for

Agriculture

c. Certification

C. Unfunded Mandates Reform Act

(UMRA)

D. Paperwork Reduction Act

I. Executive Summary

A. Background

The Phoenix area violates both the

annual and 24-hour national healthbased standards for particulate matter

with diameters of 10 microns or less.

Consequently, Maricopa County

residents continue to breathe unhealthy

air. Particulate matter affects the

respiratory system and can cause

damage to lung tissue and premature

death. The elderly, children, and people

with chronic lung disease, influenza, or

asthma are especially sensitive to high

levels of particulate matter. EPA

recently established a new standard for

particulate matter of diameters of 2.5

microns or less and also revised the

PM–10 standards; however, today’s

proposal does not address these new

standards.

The primary cause of the PM–10

problem is dust on paved roads kicked

up by vehicle traffic, and windblown

dust from construction sites, earth

moving operations, unpaved parking

lots and roads, disturbed vacant lots,

agricultural fields and aprons, and other

disturbed areas.

When an area violates a health-based

standard, the Clean Air Act (CAA)

requires that the area be designated as

nonattainment for that pollutant.

Phoenix was originally designated and

classified as a moderate nonattainment

area for particulate matter, and Arizona

was required to develop a plan that put

into place a basic set of control

measures. These measures did not

adequately control the particulate

pollution problem. When the area failed

to attain the standards in 1994 it was

reclassified as a serious nonattainment

area, and the State is now required to

develop a plan with more

comprehensive control measures.

Despite the fact that the State is now

working on its serious area plan, EPA is

under court order, as a result of a

lawsuit by the Arizona Center for Law

in the Public Interest (ACLPI), to

develop a moderate area federal

implementation plan (FIP) for the

Maricopa area. EPA is required to

prepare this FIP because the State does

not have an approved moderate area

plan. Under the court order, EPA has

until March 20, 1998, to propose and

July 18, 1998, to finalize the FIP.

EPA has determined that not all the

basic controls on sources contributing to

violations of the particulate standards

are in place. While the State has

implemented a number of measures

including controls on construction and

earth moving operations, as well as a

vehicle emission inspection and

maintenance program and a clean

burning gasoline program, there remains

a need for additional emissions

reductions. Having considered its

authority and resource constraints, EPA

is proposing two measures in the FIP for

the control of dust from unpaved roads,

parking lots, and vacant lots and

agricultural fields and aprons. These

measures will contribute to the eventual

attainment of both the annual and 24-

hour PM–10 standards.

The State intends to submit its serious

area particulate plan in the summer of

1998. If the plan includes control

measures for the sources covered by the

FIP and those measures are approved by

EPA, the Agency will be able to

withdraw the final FIP measures. EPA

will continue working with the

appropriate State and local agencies, as

well as the agricultural community and

the cities in the metropolitan area, to

replace the FIP measures with State

measures. EPA believes that clean air is

likely to be achieved faster, and in

greater harmony with local economic

and community goals, if its role as a

backstop is minimized by effective State

and local actions. Because of the

willingness of the State and local

communities to identify and pursue

solutions to their air quality problems,

as evidenced by the Governor’s Air

Quality Strategies Task Force, EPA

expects successful State and local

action.

B. FIP Proposal

EPA’s FIP proposal includes a fugitive

dust rule and an enforceable

commitment in regulatory form to

implement control measures for

agricultural PM–10 sources by July

2000. These are discussed in more detail

below. During the development of these

measures, EPA held numerous meetings

with the affected community. The

purpose of these meetings was not only

to inform the public of EPA’s FIP

obligation and the need for the Agency

to develop an adequate moderate area

PM–10 plan, but also to help EPA craft

air quality rules that meet both the

public health and economic needs of

this area. During all of these discussions

there was an ongoing dialogue regarding

what would be needed to replace the

FIP with appropriate State measures.

EPA appreciates the information that

was provided by the community during

the development phase of the proposed

FIP, and the Agency will continue to

work with the community in the

development of the State’s serious area

plan. EPA is hopeful that the local

planning effort will result in an

approvable SIP that will allow EPA to

withdraw its FIP.

Fugitive Dust Rule

Although EPA has approved a

Maricopa County rule (MCESD Rule

310) which requires controls for

unpaved roads, unpaved parking lots

and vacant lots, the County is not

adequately enforcing its rule for these

three sources due to lack of resources.

Therefore, EPA has developed a FIP rule

that proposes specific controls that will

ensure adequate enforcement for these

sources. For each source category, the

FIP rule includes three to four control

measure options and allows submittal of

alternative control measures subject to

EPA approval. In addition to the FIP

rule, EPA is addressing the resource

issue by providing additional inspection

resources to MCESD through a CAA

section 105 grant. These resources will

be used by the County to verify

compliance with the FIP rule. In order

to remove the FIP requirement, MCESD

will have to submit to EPA a credible

implementation strategy for Rule 310,

including the provision of the

additional inspection and enforcement

resources needed to ensure

implementation of its rule. Individual

cities can reduce the scope of the FIP

once EPA has approved ordinances

submitted as SIP revisions that

eliminate and/or control these sources.

Enforceable Commitment for

Agriculture

As mentioned above, EPA has

approved Maricopa County Rule 310

which requires control of fugitive dust

sources, including agricultural sources.

However, MCESD is not ensuring

adequate enforcement of the rule for

agricultural fields and aprons.

Therefore, EPA has developed an

enforceable commitment in regulatory

form for the FIP that requires EPA to

propose controls on agricultural sources

by September 1999 and implement

these controls by July 2000. In

discussions with key stakeholders,

general agreement was reached that

these controls will be in the form of best

management practices. EPA believes

that this approach will ensure

successful dust control in Maricopa’s

unique environment. In order to remove

the FIP requirements, the State will

need to submit and received approval of

a SIP measure that replaces the

enforceable commitment. EPA is

working closely with the regulatory

agencies and the agricultural

community to accomplish this goal.
15922 Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules

1 ‘‘Maricopa,’’ ‘‘Maricopa County’’ and ‘‘Phoenix’’

are used interchangeably throughout this proposal

to refer to the nonattainment area.

2There are two PM–10 NAAQS, a 24-hour

standard and an annual standard. 40 CFR 50.6. EPA

promulgated these NAAQS on July 1, 1987 (52 FR

24672), replacing standards for total suspended

particulate with new standards applying only to

particulate matter up to 10 microns in diameter

(PM–10). At that time, EPA established two PM–10

standards. The annual PM–10 standard is attained

when the expected annual arithmetic average of the

24-hour samples for a period of one year does not

exceed 50 micrograms per cubic meter (μg/m3). The

24-hour PM–10 standard of 150 μg/m3 is attained

if samples taken for 24-hour periods have no more

than one expected exceedance per year, averaged

over 3 years. See 40 CFR 50.6 and 40 CFR part 50,

Appendix K.

On July 18, 1997, EPA revised both the annual

and the 24-hour PM–10 standards and also

established two new standards for PM, both

applying only to particulate matter up to 2.5

microns in diameter (PM–2.5)(62 FR 38651). While

the revised suite of PM standards reflects an overall

strengthening of the regulatory standard for

particulate matter, the revised 24-hour PM–10

standard, viewed by itself, represents a relaxation

of that standard. As such, for areas such as Phoenix

that had not attained the pre-existing 24-hour

standard at the time of the relaxation, CAA section

172(e) calls for application of controls to be

promulgated by EPA that are no less stringent than

would have been required for areas designated

nonattainment prior to the relaxation. While today’s

proposed actions relate only to the CAA

requirements concerning the 24-hour and annual

PM–10 standards, as originally promulgated in

1987, the proposed FIP is consistent with the

section 172(e) requirement.

3While the serious area PM–10 CAA

requirements are referenced periodically

throughout this notice, EPA’s FIP obligation, the

subject of today’s proposal, relates only to the

moderate area statutory requirements.

4By letter dated December 11, 1997 from Russell

Rhoades, ADEQ, to Felicia Marcus, EPA, Arizona

submitted revisions to the Arizona SIP for achieving

and maintaining the PM–10 NAAQS. These

revisions consist of particulate control measures in

the document ‘‘Serious Area Committed Particulate

Control Measures for PM–10 for the Maricopa

County Nonattainment Area and Support Technical

Analysis,’’ Maricopa Association of Governments

(MAG), December 1997. On February 6, 1998, EPA

found that these measures meet the Agency’s

completeness criteria as set forth at 40 CFR part 51,

Appendix V, but has not yet approved or

disapproved them. Also on February 6, 1998, EPA

found, pursuant to CAA section 179(a), that Arizona

had failed to submit the serious area nonattainment

plan for Phoenix by the required date. In the same

rule, EPA found that Arizona had failed to submit

certain portions of the moderate area plan for the

area. 63 FR 9423 (February 25, 1998). These

moderate area portions are discussed further below.

5See ‘‘State Implementation Plans; General

Preamble for the Implementation of Title I of the

Clean Air Act Amendments of 1990,’’ (General

Preamble) 57 FR 13498 (April 16, 1992) and 57 FR

18070 (April 28, 1992).

Tribal Issues

There are three Indian reservations

located within the Phoenix

nonattainment area and which therefore

could be considered subject to the FIP.

However, since this FIP is designed to

fill a gap that exists in the State plan,

and the State plan does not apply to

sources within Indian country, EPA has

decided it is inappropriate to include

the Indian reservations in this FIP. All

three tribes have expressed an interest

in developing air quality programs. EPA

will develop the data, in cooperation

with the tribes, that is needed to

properly assess whether controls are

required to attain the standards. EPA

will ensure that controls are

implemented either through EPAapproved tribal measures or, if

necessary, federal measures.

C. Public Involvement in the FIP Process

Each area has its own unique qualities

and concerns. EPA can fully understand

those concerns, and plans to take them

into account, through direct

participation by the affected

community; therefore, in addition to the

meetings that EPA has already had with

the Phoenix community, there will be

additional opportunities for public

input. EPA wants to make the final plan

a product of local involvement and

consensus. EPA believes strongly that it

can best fulfill the goal of the Clean Air

Act—that is, clean and healthy air for

everyone—and meet the Agency’s courtordered obligations by preparing this

plan with the input of the local

community.

After this proposed action is signed

and published in the Federal Register,

EPA will hold a workshop and public

hearing on April 16, 1998 in the City of

Phoenix. The workshop will provide an

opportunity for EPA to explain to the

community why it is imposing this FIP,

what measures are included in this FIP,

and who will potentially be impacted by

the FIP. The workshop will also provide

the community the opportunity to ask

questions of EPA, and to make

suggestions with respect to its proposed

action. The public hearing will follow

the workshop. During the public

hearing, EPA will be taking formal

comment on the FIP proposal. The

public comment period will begin upon

publication of the FIP proposal and will

remain open for 30 days following the

public hearing, or until May 18, 1998.

EPA encourages everyone who has an

interest in this proposed action to

comment upon it. EPA will consider all

comments received during the public

comment period.

II. Background

A. Clean Air Act Requirements

1. Designation and Classification

On the date of enactment of the 1990

Clean Air Act Amendments, PM–10

areas, including portions of the preexisting Maricopa County 1 PM–10

nonattainment area, meeting the

conditions of section 107(d) of the Act

were designated nonattainment for the

PM–10 national ambient air quality

standards (NAAQS) 2 by operation of

law. Once an area is designated

nonattainment, section 188 of the Clean

Air Act (CAA) outlines the process for

classification of the area and establishes

the area’s attainment date. In

accordance with section 188(a), at the

time of designation, all PM–10

nonattainment areas were initially

classified as ‘‘moderate’’ by operation of

law. 56 FR 11101 (March 15, 1991).

A moderate area could subsequently

be reclassified as ‘‘serious’’ under CAA

section 188(b)(1), if, at any time, EPA

determined that the area could not

practicably attain the PM–10 NAAQS by

the applicable attainment date for

moderate areas, December 31, 1994.

Moreover, a moderate area would be

reclassified by operation of law if EPA

determined after the applicable

attainment date that, based on actual air

quality data, the area was not in

attainment after that date. CAA section

188(b)(2).

On May 10, 1996, EPA published a

final reclassification of the Maricopa

County PM–10 nonattainment area as a

serious PM–10 nonattainment area

based on actual air quality data. 61 FR

21372. Having been reclassified, the

area is required to meet the serious area

requirements in the CAA, including a

demonstration that the area will attain

the PM–10 NAAQS as expeditiously as

practicable but no later than December

31, 2001. CAA sections 188(c)(2) and

189(b).3 Pursuant to section 189(b)(2),

the State of Arizona was required to

submit a serious area plan addressing

both PM–10 NAAQS for the area by

December 10, 1997.4

2. Moderate Area Planning

Requirements

The air quality planning requirements

for PM–10 nonattainment areas are set

out in subparts 1 and 4 of title I of the

Clean Air Act. EPA has issued a

‘‘General Preamble’’ 5 describing EPA’s

preliminary views on how the Agency

intends to review SIPs and SIP revisions

submitted under Title I of the Act,

including those state submittals

containing moderate PM–10

nonattainment area SIP provisions.

Those states containing initial

moderate PM–10 nonattainment areas

were required to submit, among other

things, the following provisions by

November 15, 1991:

(a) Provisions to assure that

reasonably available control measures

(RACM) (including such reductions in

emissions from existing sources in the

area as may be obtained through the
Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules 15923

6As will be seen below, the proposed PM–10 FIP

for the Maricopa area does not demonstrate

attainment by the applicable attainment deadline,

but rather includes the alternative demonstration

that attainment by that date is impracticable.

Therefore, section 189(c) does not apply and is not

discussed further in this notice.

7Section 110(k)(1)(A) requires the Administrator

to promulgate minimum criteria that any plan

submission must meet before EPA is required to act

on the submission. These completeness criteria are

set forth at 40 CFR part 51, Appendix V. 8See 59 FR 43956 (August 25, 1994).

adoption, at a minimum, of reasonably

available control technology (RACT))

shall be implemented no later than

December 10, 1993 (CAA sections

172(c)(1) and 189(a)(1)(C));

(b) Provisions to assure

implementation of RACT on major

stationary sources of PM–10 precursors

except where EPA has determined that

such sources do not contribute

significantly to exceedances of the PM–

10 standards (CAA section 189(e));

(c) Either a demonstration (including

air quality modeling) that the plan will

provide for attainment as expeditiously

as practicable but no later than

December 31, 1994 or a demonstration

that attainment by that date is

impracticable (CAA section

189(a)(1)(B));

(d) For plan revisions demonstrating

attainment, quantitative milestones

which are to be achieved every 3 years

and which demonstrate reasonable

further progress (RFP), as defined in

section 171(l), toward attainment by the

applicable attainment date (CAA section

189(c)); 6 and

(e) For plan revisions demonstrating

impracticability, such annual

incremental reductions in PM–10

emissions as are required by part D of

the Act or may reasonably be required

by the Administrator for the purpose of

ensuring attainment of the PM–10

NAAQS by the applicable attainment

date (CAA sections 172(c)(2) and

171(1)).

Moderate area plans were also

required to meet the generally

applicable SIP requirements for

reasonable notice and public hearing

under section 110(l), necessary

assurances that the implementing

agencies have adequate personnel,

funding and authority under section

110(a)(2)(E)(i) and 40 CFR 51.280; and

the description of enforcement methods

as required by 40 CFR 51.111, and EPA

guidance implementing these

provisions.

3. Federal Implementation Plan

Provisions

Section 110(c) of the CAA provides

that:

(1) The Administrator shall promulgate a

Federal implementation plan at any time

within 2 years after the Administrator—

(A) finds that the State has failed to make

a required submission or finds that the plan

or plan revision submitted by the State does

not satisfy the minimum criteria established

under section 110(k)(1)(A),7 or

(B) disapproves a State implementation

plan submission in whole or in part, unless

the State corrects the deficiency, and the

Administrator approves the plan or plan

revision, before the Administrator

promulgates such Federal implementation

plan.

Section 302(y) defines the term

‘‘Federal implementation plan’’ in

pertinent part, as:

A plan (or portion thereof) promulgated by

the Administrator to fill all or a portion of

a gap or otherwise correct all or a portion of

an inadequacy in a State implementation

plan, and which includes enforceable

emission limitations or other control

measures, means or techniques (including

economic incentives, such as marketable

permits or auctions of emissions allowances).

EPA has wide-ranging authority under

section 110(c) to fill in gaps left by a

State failure. EPA’s authority to

prescribe FIP measures is of three types.

First, EPA may promulgate any measure

which it has authority to issue in a nonFIP context. Second, EPA may invoke

section 110(c)’s general FIP authority

and act to cure a planning inadequacy

in any way not clearly prohibited by

statute. Third, under section 110(c) the

courts have held that EPA may exercise

all authority that the State may exercise

under the Act. For a more detailed

discussion of these authorities and

restrictions on EPA’s FIP authorities, see

59 FR 23262, 23290–23292 (May 5,

1994).

4. Indian Reservations

a. EPA’s FIP Obligation. As stated

above, the purpose of EPA’s proposed

FIP is ‘‘to fill all or a portion of a gap

or otherwise correct all or a portion of

an inadequacy in a State

implementation plan,’’ as specified in

section 302(y). Because, except in the

rare special circumstances that have not

been shown to apply to Arizona, states

have no jurisdiction to impose statutory

or regulatory requirements in Indian

country, the gaps in the Arizona PM–10

SIP for the Phoenix nonattainment area

do not extend to tribal lands. As a

result, EPA is not required in its

proposed FIP to promulgate regulations

for Indian lands within the Phoenix

nonattainment area. While EPA is not

proposing to extend the provisions of

the proposed FIP to tribal lands, as

discussed below, EPA and tribes, that

are determined to be eligible by EPA,

are authoriized under the CAA to

protect air quality throughout Indian

country.

b. EPA and Tribal CAA Authority in

Indian Country. On February 12, 1998,

EPA issued its final rule pursuant to

CAA section 301(d) specifying the

provisions of the Act for which Indian

tribes may be treated in the same

manner as states; the rule also

authorizes eligible tribes to implement

their own air programs under the Act.

63 FR 7254. In the proposed 8 and final

rule, EPA discusses generally the legal

basis under the CAA by which EPA and

tribes are authorized to regulate sources

of air pollution in Indian country.

In the rulemaking, EPA concluded

that the CAA constitutes a statutory

grant of jurisdictional authority to

Indian tribes that allows them to

develop air programs for EPA approval

in the same manner as states. 63 FR at

7254–7259.

EPA also concluded that the CAA

authorizes EPA to protect air quality

throughout Indian country. See, e.g.,

CAA sections 101(b)(1), 301(a), and

502(d), (e), and (i). Therefore, EPA

believes that it has broad legal authority

to provide federal protection in Indian

country when tribes choose not to

develop a program, fail to adopt an

adequate program or fail to adequately

implement a program. In addition,

section 301(d)(4) empowers EPA to

directly administer CAA requirements

in any case where EPA determines that

treatment of tribes as identical to States

is inappropriate or administratively

infeasible. 63 FR at 7262. See also 59 FR

at 43960.

It is EPA’s policy to aid tribes in

developing comprehensive and effective

air quality management programs by

providing technical and other assistance

to them. EPA recognizes, however, that

as it required many years to develop

state and federal programs to cover

lands subject to state jurisdiction, it will

also require time to develop tribal and

federal programs to cover reservations

and other lands subject to tribal

jurisdiction. 59 FR at 43961.

EPA promulgated 40 CFR 49.11 in the

final Tribal rule, providing that the

Agency will promulgate a FIP within a

reasonable time if tribal efforts do not

result in EPA-approved programs. 63 FR

at 7273. EPA has also undertaken an

initiative to develop a comprehensive

strategy for implementing the CAA in

Indian country that will articulate

specific steps the Agency will take to

ensure that air quality problems in

Indian country are addressed either by

EPA or the tribes themselves. This

strategy is currently in draft form. EPA
15924 Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules

9EPA then elaborates on this grass-roots approach

by discussing three components of the Agency’s

strategy: a needs assessment, including the

development of emission inventories, outreach and

communication, and training. 63 FR at 7264.

10The reader should refer to both the proposed

approval, 59 FR 38402, and the final rule, 60 FR

18010, for EPA’s interpretation of certain moderate

area PM–10 requirements of the CAA and the

Agency’s application of these interpretations to the

State’s moderate area PM–10 plan. Those notices

should also be consulted for the history of the

State’s PM–10 plan submittals and EPA’s actions

concerning them.

11For the CAA serious area PM–10 plan

requirements, see section 189(b). EPA has issued an

Addendum to the General Preamble (Addendum)

describing the Agency’s preliminary views on how

it intends to review SIPs and SIP revisions

containing serious area plan provisions. See ‘‘State

Implementation Plans for Serious PM–10

Nonattainment Areas, and Attainment Date Waivers

for PM–10 Nonattainment Areas generally;

Addendum to the General Preamble for the

Implementation of Title I of the Clean Air Act

Amendments of 1990,’’ 59 FR 41998, 42011 (August

16, 1996).

also intends to issue national

regulations covering various categories

of air pollution sources that would

apply in those situations in which a

tribe does not have an approved

program. 63 FR at 7262–7264.

In the final Tribal rule, the Agency

emphasizes that its strategy for

implementing the CAA in Indian

country is multi-pronged, ‘‘one prong of

which is federal implementation * * *

[t]he other prongs derive from a ‘grassroots’ approach in which staff in the

EPA regional offices work with

individual tribes to assess the air quality

problems and develop, in consultation

with the tribes, either tribal or federal

strategies for addressing the problems.’’

63 FR at 7264.9

EPA believes that the strategy that it

has developed for tribal lands in the

Phoenix nonattainment area, discussed

in section VI below, is consistent with

the approach outlined above. In short,

EPA intends to provide technical and

financial support to the Tribes in the

area so that they may develop their own

programs if they wish to do so, and to

develop federal measures should it

become necessary.

B. History of Arizona’s PM–10 Plans and

Related EPA Actions

1. Arizona’s Moderate Area PM–10 Plan

The State of Arizona originally

submitted a moderate area PM–10 plan

revision to EPA on November 15, 1991.

On March 4, 1992, EPA found that the

plan did not meet the Agency’s

completeness criteria at 40 CFR part 51,

Appendix V, in part because a proper

public hearing on the plan had not been

held. Thereafter the State held another

public hearing and resubmitted the SIP

revision on August 11, 1993. On

September 7, 1993 EPA found this plan

to be complete. The State submitted a

revised and updated version of the plan

on March 3, 1994. See generally 59 FR

38402, 38403 (July 28, 1994).

On April 10, 1995, EPA approved the

State’s moderate area PM–10

implementation plan revision for the

Maricopa area. 60 FR 18010. Among

other elements in that plan, EPA

approved the State’s RFP and RACM

demonstrations as meeting the

requirements of sections 171(1),

172(c)(1), 172(c)(2), and 189(a)(1)(C) of

the CAA. Based on its approval of the

RACM demonstration, EPA also

proposed to approve, as meeting the

requirements of section 189(a)(1)(B), the

State’s demonstration that even with the

implementation of all RACM by

December 10, 1993, it was impracticable

for the Maricopa area to attain the PM–

10 NAAQS by December 31, 1994.10

On May 1, 1995, the Arizona Center

for Law in the Public Interest (ACLPI)

filed a petition for review of EPA’s April

10, 1995 approval of the State’s

moderate area PM–10 plan in the United

States Court of Appeals for the Ninth

Circuit.

On May 14, 1996, the Ninth Circuit

vacated EPA’s approval of the States’s

PM–10 moderate area plan. Ober v. EPA,

84 F.3d 304 (9th Cir. 1996). In short, the

Court concluded that the State’s

moderate area plan failed to address the

moderate area CAA requirements for

attainment, RFP and RACM for the 24-

hour standard and mandated that EPA

require the State to do so. The Court

also found that EPA had failed to

provide the required opportunity for

comment with respect to the RFP and

RACM demonstrations for the annual

standard. In response to the Court’s

opinion, EPA initiated the following

actions.

2. The Microscale Plan—24-hour

Standard

In the wake of the Ninth Circuit’s

Ober opinion, EPA considered how to

appropriately implement the Court’s

directive in the context of the State’s

then-prevailing PM–10 planning efforts

for the Maricopa area. The Maricopa

area was reclassified as a serious PM–

10 nonattainment area just days before

the case was decided and, as noted

above, the State was required to submit

a new PM–10 plan meeting the serious

area requirements by December 10,

1997.11 Therefore EPA had to reconcile

the Court’s mandate that the State

submit a plan correcting its moderate

area plan deficiencies regarding the 24-

hour standard concurrent with its

responsibility to submit a plan meeting

the serious area requirements for both

NAAQS.

EPA concluded that, given the

substantial overlap of the moderate and

serious area planning requirements, it

would not be in the public interest to

require the State to divert its scarce

resources into two independent

planning exercises. At the same time,

the Agency recognized that timely

action (i.e., prior to the serious area plan

submittal deadline of December 10,

1997) was required in order to be

responsive to the Court’s mandate.

Therefore EPA, in consultation with the

Arizona Department of Environmental

Quality (ADEQ) and the MCESD,

decided that the State would

incorporate the moderate area plan

elements for the 24-hour standard into

the serious area plan, but would split

that planning effort into two related

parts. Accordingly, EPA, in a September

18, 1996 letter to ADEQ, required

submittal of a limited, locally-targeted

plan (microscale plan) analyzing air

quality impacts at specific monitoring

sites, and meeting both the moderate

and serious area requirements for the

24-hour standard by May 9, 1997

(extended from an original deadline of

April 18) and a full regional plan

meeting those requirements for both the

24-hour and annual standards by

December 10, 1997. Thus, the

microscale and regional plans taken

together would satisfy both the

moderate area requirements mandated

by the Court and the serious area

planning requirements for both

standards.

The State submitted the microscale

plan to EPA on May 9, 1997 and on

August 4, 1997, EPA approved the

following portions of the plan:

(1) under sections 172(c)(1), 189(a)(1)(C)

and 189(b)(1)(B), the provisions for

implementing RACM and best available

control technology (BACM) for the significant

source categories of disturbed cleared areas,

earth moving, and industrial haul roads; and

(2) under sections 189(a)(1)(B),

189(b)(1)(A), and 189(c), the attainment and

RFP demonstrations for the Maryvale and

Salt River monitoring sites.

(3) the resolution by the County of

Maricopa to improve the administration of

Maricopa County’s fugitive dust control

program and to foster interagency

cooperation (adopted May 14, 1997);

(4) the resolutions of intent to work

cooperatively with Maricopa County to

control the generation of fugitive dust

pollution adopted by the Cities of Phoenix

(April 9, 1997), Tempe (March 27, 1997),

Chandler (March 27, 1997), Glendale (March

25, 1997), Scottsdale (March 31, 1997), and

Mesa (April 23, 1997) and the Town of

Gilbert (April 15, 1997); and

(5) MCESD’s Rule 310 (Open Fugitive Dust

Sources), Rule 311 (Particulate Matter from
Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules 15925

12See EPA’s proposed and final actions on the

State’s microscale plan at 62 FR 31025 (June 6,

1997) and 62 FR 41856 (August 4, 1997).

13The reader is referred to the text of the opinion

for the Court’s disposition of the range of issues

raised by ACLPI in its petition. See 84 F.3d 304 (9th

Cir. 1996). See also 61 FR 54972 in which EPA

preliminarily addresses the Court’s opinion as it

relates to the RACM, RFP and attainment

demonstrations for the annual standard and 62 FR

31025 in which EPA discusses the opinion as it

relates to the required demonstrations for the 24-

hour standard.

Process Industries) and Rule 316

(Nonmetallic Mineral Mining and

Processing).

In the same action, EPA disapproved

the following provisions of the State’s

microscale plan:

(1) under sections 172(c)(1), 189(a)(1)(C)

and 189(b)(1)(B), the provisions for

implementing RACM and BACM for the

significant source categories of agricultural

fields, agricultural aprons, vacant lands,

unpaved parking lots, and unpaved roads;

and

(2) under sections 189(a)(1)(B),

189(b)(1)(A), and 189(c)(1), the attainment

and RFP demonstrations at the West

Chandler and Gilbert monitoring sites.12

3. EPA Actions on Arizona’s Moderate

Area PM–10 Plan Post-Ober With

Respect to the Annual Standard

In response to the Ober decision, EPA

provided an opportunity for public

comment on the State’s justifications for

rejecting certain measures as RACM and

on the emission reduction credit granted

by the Agency for Rule 310 as it related

to the State’s RFP demonstration. EPA

also proposed to restore its approval of

the RACM, RFP and impracticability

demonstrations in the State’s moderate

area plan with respect to the annual

PM–10 standard. 61 FR 54972 (October

23, 1996).

As a result of the extensive technical

work associated with the State’s

microscale plan, EPA has concluded, as

discussed in detail in section III below,

that it is no longer appropriate to restore

its approval of the demonstrations in the

State’s moderate area plan for the

annual standard. Therefore, EPA is

proposing to withdraw its 1996 proposal

and, instead, is now proposing to

disapprove the impracticability and

RACM demonstrations in that plan.

C. History of PM–10 FIP Litigation in

Phoenix

On June 28, 1994, ACLPI filed, on

behalf of two Phoenix residents, a

complaint, No. CIV 94–1318 PHX PGR,

in the United States District Court for

the District of Arizona alleging that EPA

was required, pursuant to section 110(c)

of the CAA, to have promulgated a

moderate area PM–10 FIP for Phoenix

by March 4, 1994, two years after EPA’s

finding that the State’s moderate area

plan was incomplete. ACLPI sought,

among other things, an order requiring

EPA to promulgate a final FIP in 12

months. On February 28, 1995, the

district court approved a consent decree

requiring EPA to take final action on the

moderate area plan by March 1, 1995. If

EPA approved the plan, as turned out to

be the case, the district court action

would be stayed pending appellate

review.

On May 1, 1995, ACLPI filed a

petition for review of EPA’s April 10,

1995 approval of Arizona’s moderate

area PM–10 plan for the Phoenix area in

the United States Court of Appeals for

the Ninth Circuit. Ober v. EPA, No. 95–

70352. On May 14, 1996, the Court

issued its opinion in the Ober case

vacating EPA’s approval of the State’s

plan.13

As a result of the Ninth Circuit’s

opinion in Ober, the stay of proceedings

in the district court FIP case was lifted.

On November 29, 1996 and March 25,

1997, respectively, the court approved a

second consent decree and a modified

second consent decree in which EPA

agreed that if the Agency disapproved

the State’s microscale plan in whole or

in part, the Administrator is required to

sign by March 20, 1998 a Notice of

Proposed Rulemaking (NPRM) that sets

forth a proposed FIP for Phoenix that

meets the moderate area PM–10

requirements for the annual and 24-hour

standards for attainment, RACM and

RFP as set forth in CAA sections

189(a)(1)(B) and (C), and 172(c)(2) or

189(c)(1). Under the decree, EPA must

sign a Notice of Final Rulemaking

(NFRM) setting forth the final FIP by

July 18, 1998. EPA’s FIP obligation is

relieved as to any portion of the plan for

which EPA signs a NFRM approving

corrective SIP revisions by July 18,

1998.

III. SIP Actions

A. Proposed Disapproval of Moderate

Area Plan

In its July 28, 1994 proposed approval

of the State’s moderate area plan, EPA

noted that the plan’s emission inventory

identified fugitive dust sources as

contributing more than 50 percent of the

PM–10 emissions in the Phoenix area.

These fugitive dust sources included,

but were not limited to, construction

and demolition activities, farming

operations, uncovered haul trucks, and

emissions from unpaved roads. 59 FR

38405. EPA also stated that it believed

that Maricopa County’s fugitive dust

rule, Rule 310, fully addressed fugitive

dust sources in the area. 59 FR 38404.

Based in part on this belief and its

evaluation of the balance of RACM in

the plan, EPA proposed and eventually

found that the moderate area plan

assured timely implementation of

RACM, and that these RACM were

sufficient to demonstrate RFP but were

insufficient to demonstrate attainment

by the moderate area deadline of

December 31, 1994. EPA, therefore,

approved the RACM, RFP, and

impracticability demonstrations in the

State’s moderate area plan. 60 FR 18010.

As discussed above, EPA’s approval

of the moderate area plan was

subsequently vacated in Ober. In

October 1996, EPA proposed to restore

its approval of the RACM, RFP and

impracticability demonstrations in the

State’s moderate area plan for the

annual standard. 61 FR 54972. This

proposal was based, in part, on the

Agency’s continued belief that Rule 310

represented RACM for fugitive dust

sources in Maricopa County.

As described previously, EPA

subsequently approved in part and

disapproved in part the State’s

microscale plan for the 24-hour

standard. In its evaluation of the

microscale plan, EPA found that, in fact,

Rule 310, due to inadequate

commitment of resources by the State,

does not assure enforcement of RACM

on a number of fugitive dust sources,

including unpaved roads and unpaved

parking lots, that are legally subject to

the rule. In addition, EPA found that

there were no RACM that applied for

agricultural sources. 62 FR 41862.

While these findings were made in

the context of evaluating RACM for the

24-hour standard, the findings also

apply to the annual standard. As noted

above, EPA’s 1994 approval of the

State’s moderate area plan relied in

large part on the Agency’s finding that

Rule 310 constituted RACM for fugitive

dust sources. As a result of its findings

with respect to the microscale plan, EPA

no longer considers Rule 310 to satisfy

the Act’s requirement for enforceable

RACM for fugitive dust sources not

permitted by the County under the rule;

therefore, since the Agency can no

longer find that the State’s moderate

area plan assures the required source

compliance with Rule 310 and, hence,

does not ensure enforcement of RACM

as required by the Act, EPA, is

proposing to disapprove the RACM

demonstration for the annual standard

in the State’s moderate area plan.

In order for a moderate area plan to

demonstrate that attainment is

impracticable, it must make that

showing in light of implementation of

all RACM. 57 FR 13544. Since EPA is

now proposing to disapprove the RACM
15926 Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules

14The discussion in section IV.A. regarding EPA’s

views of the status of the CAA’s moderate area

attainment requirements following an area’s

reclassification to serious is applicable here and the

reader is referred to that section.

15While EPA could have sought clarification on

this issue from the Ninth Circuit, the Agency did

not do so because such a review would necessarily

have occurred without benefit of a thorough

briefing on the issue and in the absence of an

administrative record. The Agency does, however,

reserve its right to assert its interpretation in any

challenge to EPA’s implementation of the Court’s

remedies or in the context of other reclassifications.

demonstration in the State’s moderate

area plan, the Agency is also proposing

to disapprove the demonstration

contained in that plan that attainment

by the moderate area deadline of

December 31, 1994 was impracticable.14

EPA, however, is not proposing to

disapprove the RFP demonstration in

the State’s moderate area plan. The

estimated emission reductions from the

implementation of Rule 310 on

unpermitted sources accounted for less

than 20 percent of the total emission

reductions from the plan. Even without

the reductions from the unpermitted

sources, EPA believes that plan still

contains sufficient emission reductions

from other measures to demonstrate RFP

for the annual standard and, therefore,

disapproval is not warranted. This

issue, however, is academic since, as

noted before, EPA is withdrawing its

proposal to restore approval of the RFP

demonstration for the annual standard

in the State’s plan and is substituting its

own proposed RFP demonstration for

that standard.

B. Withdrawal of Proposal to Restore

Moderate Area Plan Demonstrations for

the Annual PM–10 Standard

As a consequence of the proposed

disapprovals discussed above, EPA is

today withdrawing its October 26, 1996

proposal (61 FR 54972) to restore the

Agency’s approval of the RACM and

impracticability demonstrations for the

annual standard in the State’s moderate

area plan.

EPA is today also withdrawing its

proposal to restore approval of the RFP

demonstration for the annual standard

in the State’s plan. While EPA continues

to believe that the plan as a whole

continues to demonstrate RFP, its

previous analysis of the State’s RFP

demonstration is no longer valid

because it relied in part upon emission

reductions from the implementation of

Rule 310 on a number of unpermitted

source categories. Under its CAA

section 110(c) authority, EPA is

proposing its own RFP demonstration

for the annual standard as described in

section V.C.

IV. Moderate Area PM–10 Planning

Requirements for the FIP Proposal

A. Attainment/Impracticability

Demonstration

Because the moderate area attainment

deadline, December 31, 1994, has

passed, EPA is confronted with the

issue of how to define the moderate area

requirements applicable to the Agency’s

proposed FIP. EPA believes that because

the Maricopa area was reclassified from

a moderate to a serious nonattainment

area, the moderate area requirements

(demonstration of impracticability or

attainment by no later than December

31, 1994) have been superseded by the

serious area attainment requirement

(attainment by no later than December

31, 2001) and are therefore now moot.

Having reviewed the CAA’s moderate

and serious area PM–10 attainment

provisions, EPA has concluded that

when a moderate PM–10 area has been

reclassified after the moderate area

attainment deadline has passed and

been replaced with a new deadline, the

moderate area deadline no longer has

any logical, practical or legal

significance.

Thus, under this interpretation, there

would be no need for the proposed FIP,

to the extent that it is intended to meet

the CAA’s moderate area requirements,

to demonstrate attainment. In other

words, such an attainment

demonstration would only be required

when the State submits its complete

serious area plan to comply with the

section 189(b)(1) attainment

demonstration requirement. EPA

believes that its interpretation can be

reconciled with the Ober Court’s

directive that EPA require the State to

address the moderate area attainment

requirements for the 24-hour standard

and that such an interpretation is

reasonable given the legal and factual

context in which that case was decided.

EPA’s reasoning is explained in detail at

61 FR 54972, 54974–54975 (October 23,

1996). Nevertheless, EPA complied with

the Court’s remedies regarding the

moderate area attainment requirements

by directing the State to meet those

requirements in the microscale plan.15

Having complied with the Court

opinion by directing that the State meet

the moderate area attainment

requirements in its planning efforts,

EPA discerns no basis for applying

different requirements to the Agency in

promulgating a moderate area FIP that is

intended to correct State planning

deficiencies.

Having determined that the proposed

FIP must meet the CAA’s moderate area

attainment requirements, EPA has

concluded that since the December 31,

1994 deadline has passed and the

Maricopa area has been reclassified, the

only attainment deadline currently

applicable to the area is the serious area

deadline, that is, achievement of

attainment as expeditiously as

practicable, but no later than December

31, 2001. Thus, consistent with the

terms of section 189(a)(1)(B), the

moderate FIP must either demonstrate

attainment of the PM–10 NAAQS as

expeditiously as practicable but no later

than December 31, 2001, or,

alternatively demonstrate that

attainment by that date is impracticable.

B. RACM/RACT Demonstration

Sections 172(c)(1) and 189(a)(1)(C)

read together require that moderate area

PM–10 plans include RACM and RACT

for existing sources of PM–10. These

plans were to provide for

implementation of RACM/RACT no

later than December 10, 1993. Since the

moderate area deadline for the

implementation of RACM/RACT has

passed, EPA has concluded that the

RACM/RACT required in the FIP must

be implemented ‘‘as soon as possible.’’

Delaney v. EPA, 898 F.2d 687, 691 (9th

Cir. 1990). EPA has interpreted this

requirement to be ‘‘as soon as

practicable.’’ See 55 FR 41204, 41210

(October 1, 1990).

The methodology for determining

RACM/RACT is described in detail in

the General Preamble. 57 FR 13498,

13540–13541. In summary, EPA

suggests starting to define RACM with

the list of available control measures for

fugitive dust, residential wood

combustion, and prescribed burning

contained in Appendices C1, C2, and C3

of the General Preamble and adding to

this list any additional control measures

proposed and documented in public

comments. Any measures that apply to

emission sources of PM–10 and that are

de minimis and any measures that are

unreasonable for technology reasons or

because of the cost of the control in the

area can then be culled from the list. In

addition, potential RACM may be culled

from the list if a measure cannot be

implemented on a schedule that would

advance the date for attainment in the

area. 57 13498, 13560.

In addressing cost issues, the General

Preamble suggests that in case of public

sector sources and control measures, the

cost evaluation should consider the

impact of the reasonableness of the

measures on the governmental entity

that must bear the responsibility for

their implementation. 57 FR 13541.

The General Preamble does not define

‘‘de minimis’’ except to say that it

would be unreasonable to apply
Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules 15927

16EPA originally set forth preliminary guidance

on the RFP requirements for such plans in its final

rule approving the Arizona moderate area PM–10

plan for the Phoenix area. See 60 FR 18010, 18013.

The Agency subsequently clarified portions of that

guidance in its proposal to restore the annual

standard demonstrations in the State’s moderate

area plan following the Ninth Circuit’s Ober

decision. See 61 FR 54972, 54973–54974. The

reader is referred to these notices for an expanded

discussion of the Agency’s interpretation of the RFP

requirements for moderate PM–10 areas

demonstrating impracticability.

17See section IV. above.

18 EPA’s FIP obligation was initially triggered by

an incompleteness finding on the State’s moderate

area plan submittal. Although EPA subsequently

determined the submittal to be complete, the FIP

obligation continues until there is a fully approved

SIP in place.

controls to sources that are negligible

contributors to ambient concentrations.

57 FR 13540, footnote 18. The

regulatory scheme for PM in subpart 4

of the CAA establishes two graduated

levels of controls, RACM and BACM,

depending on the severity of the area’s

air quality. See CAA section 189(a) and

(b). These statutory requirements,

applicable to moderate and serious

areas, respectively, clearly contemplate

that smaller PM sources need not, in the

first instance, bear the burden of

emission reductions. Thus, in

determining the initial level of control,

it is appropriate to focus on what is

reasonable and practicable for

significant sources of PM emissions.

For its proposed FIP, EPA is

proposing to rely on the criteria applied

to define significant contributors under

its new source permitting programs (40

CFR 51.165(b)) as a surrogate for

determining which source categories

require the application of RACM. Under

EPA’s new source permitting programs,

a PM–10 source is considered to be a

‘‘significant contributor’’ if it

contributes 5 μg/m3 or more of PM–10

to a location of expected 24-hour

exceedances and 1 μg/m3 or more to a

location of expected annual violation.

Therefore, a de minimis source category

for the purposes of defining which

source categories require the application

of RACM under section 189(a)(1)(C), is

proposed to be one that contributes less

than 5 μg/m3 of PM–10 to a location of

expected 24-hour exceedances and less

than 1 μg/m3 to a location of expected

annual violations.

It should be emphasized that the de

minimis criterion is invoked solely for

the purposes of determining which

source categories need RACM and not

for determining which source categories

need controls for attainment. In

establishing this RACM de minimis

criterion, EPA is not taking the position

that de minimis RACM source

categories can escape controls if such

controls are needed for attainment or

RFP. In that case, it is the Agency’s

position that the level of control on such

insignificant sources need only be at the

level required to demonstrate reasonable

further progress and expeditious

attainment and that this level need not

be justified under section 189(a)(1)(C) as

RACM.

For any RACM that EPA rejects for

reasons of technology, cost, size of

source category or timing of

implementation as described above, the

Agency must provide a reasoned

justification for the rejection. Once the

final list of RACM is defined, each

RACM must be converted into a legally

enforceable vehicle such as a rule,

permit, or other enforceable document.

57 FR 13498, 13541.

C. Reasonable Further Progress (RFP)

Demonstration to Follow

EPA has concluded that for PM–10

plans that demonstrate that it is

impracticable for an area to attain the

NAAQS by the applicable attainment

date, the governing statutory

requirement for RFP is section 172(c)(2)

as defined by section 171(l).16 Section

172(c)(2) of the Act states that

nonattainment plans shall require

reasonable further progress (RFP). RFP

is defined in section 171(1) as ‘‘such

annual incremental reductions in

emissions of the relevant air pollutant as

are required by this part [D] or may

reasonably be required by [EPA] for the

purpose of ensuring attainment of the

applicable [NAAQS] by the applicable

date.’’

EPA has interpreted the RFP

requirement for areas demonstrating

impracticability as being met by a

showing that the implementation of all

RACM has resulted in incremental

emission reductions below preimplementation levels. EPA believes

that this interpretation is consistent

with the definition in section 171(l) and

with the statutory term ‘‘reasonable

further progress.’’

V. Summary of EPA’s FIP Proposal

As a moderate area plan, EPA’s

proposed FIP must demonstrate

attainment of both the annual and 24-

hour PM–10 standards by December 31,

2001 (as a result of the passing of the

moderate area deadline and the

reclassification to serious) and provide

for expeditious implementation of

RACM for all significant source

categories, or demonstrate that even

with RACM it is impracticable for the

area to attain by that date. The proposed

FIP must also demonstrate RFP

consistent with the attainment or

impracticability demonstration.17

EPA’s FIP obligation arises only as to

SIP provisions that are not approved. As

discussed previously in section II.B.2.,

EPA has already approved RACM,

attainment, and RFP demonstrations for

certain sources of source categories in

the Phoenix area. Specifically, EPA has

already approved RACM for disturbed

cleared areas (e.g., construction

sources), earth moving, industrial haul

roads, and stationary sources and the

attainment and RFP demonstrations for

the 24-hour standard at the Maryvale

and Salt River monitoring sites. 62 FR

41856. As a result, this proposed FIP

does not address these SIP elements.

EPA, however, has disapproved the

State’s RACM demonstrations for the

significant source categories of unpaved

roads, unpaved parking lots, vacant lots,

and agricultural fields and aprons as

well as its attainment and RFP

demonstrations for the 24-hour standard

at the Gilbert and West Chandler

monitoring sites. 62 FR 41856. In

addition, EPA is proposing to

disapprove the RACM and attainment/

impracticability demonstrations for the

annual standard in the State’s moderate

area plan and to revise the State’s RFP

demonstration for this standard.18 See

Section III.A.

The following sections describe EPA’s

proposals to address each of the

outstanding elements of the Phoenix

moderate plan: RACM/RACT

demonstration, attainment/

impracticability demonstrations, and

RFP demonstrations.

A. RACM/RACT Demonstration

1. RACT and PM–10 Precursors

a. RACT. In the General Preamble,

EPA recommends that major stationary

sources of PM–10 be the starting point

for a reasonably available control

technology (RACT) analysis. 57 FR

13541. Stationary sources of PM–10 in

the Phoenix area include power plants,

concrete manufacturing, sand and gravel

operations, and cotton ginning. MCESD

has adopted regulations requiring RACT

for stationary sources of PM–10: Rule

311, ‘‘Particulate Matter from Process

Industries,’’ and Rule 316, ‘‘Nonmetallic

Mineral Mining and Processing.’’ These

measures were approved by EPA in

1995 as RACT for PM–10 stationary

sources as part of the moderate area

plan approval. 60 FR 18009. While not

at issue in the litigation regarding that

plan’s approval, EPA’s approval of these

rules was also incidentally vacated by

the Ober decision. The Agency restored

these RACT rules to the SIP as part of

its action on the microscale plan. 62 FR

41862.
15928 Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules

19The 1991 MAG plan identified 79 potential

RACM with an additional 82 potential measures

identified from public comment. Many of these

public comment measures, however, duplicated

measures on the original list of 79.

b. PM–10 Precursors. Under CAA

section 189(e), the control requirements

applicable to major stationary sources of

PM–10 must also be applied to major

stationary sources of PM–10 precursors,

unless EPA determines such sources do

not contribute significantly to PM–10

levels in excess of the NAAQS in the

area. ‘‘Significantly’’ is not defined in

either the Act or in the General

Preamble. Rather, for moderate areas,

the determination is to be made on a

case-by-case basis. 57 FR at 13539. For

this action, EPA proposes to rely on the

criteria applied under its new source

permitting programs (40 CFR 51.165(b))

to guide its review of whether major

stationary sources of PM–10 precursors

significantly contribute to PM–10 levels

in excess of the standard. See Section

IV.B. A major stationary source in a

moderate area is one that emits or has

the potential to emit 100 tons per year

or more of PM–10 or a PM–10 precursor.

57 FR 13538.

PM–10 precursors can include sulfur

oxides (SOX), nitrogen oxides (NOX),

ammonia, and volatile organic

compounds (VOCs). In the Phoenix area,

VOCs are not important in secondary

particulate formation. Sulfur oxide

emissions in the area are dominated by

emissions from non-road engines and

thus major sources of SOX account for

less than 10 percent of the total

inventory. Nitrogen oxide emissions are

almost entirely (90 percent) from onand non-road engines, with major

stationary sources accounting for only

4.3 percent of the total inventory.

Livestock operations (which are not

considered major point sources) account

for 99.8 percent of ammonia emissions.

See Tables 2–2 and B3–1 in ‘‘1994

Regional PM–10 Emission Inventory for

the Maricopa County Nonattainment

Area,’’ Draft Final Report, MAG, May

1997. In total, major point sources

account for less than 7 percent of the

total precursor inventory.

Draft PM–10 air quality modeling for

the Phoenix nonattainment area

indicates that exceedances of both the

24-hour and annual standards are

attributable chiefly to direct particulate

matter emissions from re-entrained dust

from paved roads and fugitive dust from

disturbed surfaces such as construction

sites and agricultural fields. The draft

modeling also indicates that secondary

particulate formation from all sources of

precursors (including natural

background) contributes from 3.6 to 9.4

μg/m3 to the modeled 24-hour episodes.

See ‘‘Technical Support Document for

the Regional PM–10 Modeling in

Support of the 1997 Serious Area PM–

10 Plan for Maricopa County

Nonattainment Area,’’ Draft Report,

MAG, October 1997, Table 3–26 (MAG

Modeling TSD). No contribution from

secondary particulates to the annual

standard was estimated in the draft

modeling; however, based on a crude

average of the results of the eight 24-

hour episodes modeled, the annual total

impact (including background) of

secondary particulates is around 5.6 μg/

m3.

From these modeling results, and

assuming that a source’s contribution to

secondary particulate levels is

proportional to its presence in the

inventory, major stationary sources of

PM–10 precursors contribute no more

than 0.6 μg/m3 to the 24-hour standard

and 0.3 μg/m3 to the annual standard

(the actual contribution is likely to be

less when the background levels of

secondary particulates are factored out).

Both these levels are well below the 5

μg/m3 24-hour standard and 1 μg/m3

annual standard significance levels;

therefore, EPA proposes to find, based

on existing modeling, that major

stationary sources of PM–10 precursors

do not contribute significantly to PM–10

levels in the Maricopa area which

exceed the PM–10 NAAQS, and

therefore, RACT on these major sources

is not required under section 189(e).

With this proposal, which is based on

an assessment of the current mix of

sources and meteorological patterns,

EPA is not drawing any conclusions on

the potential future need or desirability

of controls on major sources of PM–10

precursors to assure eventual attainment

of the PM–10 standard in the Phoenix

area.

2. RACM Approach

As discussed in section IV.B. above,

EPA’s General Preamble suggests

determining RACM by beginning with

the list of measures found in Appendix

C to the General Preamble and adding

to that list any measures which have

been suggested by public comments.

Any measures that are determined to

apply to emission sources of PM–10 that

are de minimis and any measures that

are technologically infeasible or have

unreasonable costs can then be culled

from the list. A reasoned justification

must be provided for each measure that

is rejected as RACM. 57 FR 13498,

13540.

EPA has identified a list of 99

potential control measures. This list of

measures is taken from the list of

measures developed for the State’s 1991

moderate area plan and includes the

measures found in Appendix C to the

General Preamble as well as measures

recommended by the Maricopa air

agencies and in public comments on the

moderate area plan.19 The measures

range from fugitive dust and

transportation control measures to

measures which achieve reductions

from national transportation sources

such as aircraft and trains.

Before evaluating measures as RACM,

EPA first screened the list of 99

measures to determine which measures

were applicable to the Phoenix area and

for which EPA had legal authority. EPA

then screened the list to determine

which measures it has already approved

as State RACM or adopted at the federal

level and considers RACM. Where EPA

has already determined a measure to be

RACM, no further analysis of the

measure is necessary. Finally, the

Agency evaluated the resulting shorter

list of measures based on the General

Preamble’s RACM criteria to identify

which measures constituted RACM for

the Phoenix area.

Readers should note that the

following analysis is meant to apply

only in the limited instance of this

moderate area PM–10 FIP for the

Maricopa County area and only to the

determination of the availability and

reasonableness of controls for adoption

and implementation by EPA and not by

the State of Arizona, its local

jurisdictions or other states. In contrast

to EPA’s regulatory authority as a

federal executive-branch agency, the

concept of ‘‘state’’ as used in the Clean

Air Act embodies both the state’s

executive and more extensive legislative

functions and therefore includes the

authority not only to regulate but also to

establish new legal authority and to

raise funds for necessary programs. As

a result, it is likely that the State could

adopt and implement a broader range of

RACM.

Because there are both a 24-hour and

an annual PM–10 standard, EPA must

evaluate whether each measure is

reasonably available for each standard.

However, except for the de minimis

criterion discussed later, the criteria

EPA used to determine potential RACM

are equally applicable to both PM–10

standards, that is, each criterion and the

results of applying the criterion to a

measure do not vary depending on

whether the measure is being evaluated

for the 24-hour or annual standard. As

a result, a completely separate RACM

analysis for each standard is not

warranted and has not been performed.
Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules 15929

20Marine vessel operations here mean

commercial port traffic operations and not pleasure

or recreational boating operations. Emissions from

pleasure/recreational boat engines are covered

under non-road engine standards.

21Nor do such flow improvements have a

beneficial effect on secondary particulate levels

since emissions of the major PM–10 precursor from

on-road motor vehicles, NOx, increase with speed.

3. Federal Implementation Criteria

a. Applicability to the Phoenix Area.

Before a measure can be considered as

potential RACM, EPA must first

determine if the measure would have

any inherent potential to reduce PM–10

emissions in the Phoenix area. Some of

the listed measures cover sources that

are not represented in the Phoenix area,

such as marine vessel operations 20 and

deicing materials, and were rejected

from further evaluation on this basis.

In addition, many of the 99 measures

were taken from the ozone or CO air

quality plans for the Phoenix area and

are primarily intended to reduce CO or

ozone precursor emissions. Several of

these measures do not reduce PM–10

emissions. For example, since PM–10

emissions from both tailpipes and reentrained dust from paved roads are

independent of the speed of vehicles,

measures that simply improve traffic

flow and thus improve overall traffic

speeds have no effect on primarilyemitted PM–10. 21

Note that this criterion is not

addressing whether the measure could

be implemented in the Phoenix area in

a manner that would achieve PM–10

emission reductions. Implementation

feasibility will be considered as part of

the technical feasibility criterion below.

b. Existing RACM. In some instances,

EPA has already SIP-approved a

measure or very similar measure as

RACM or has promulgated at the federal

level a measure that it considers to be

RACM. Where EPA has already

determined a measure to be RACM, no

further analysis of the measure is

necessary.

c. Legal Authority. EPA must have the

legal authority under the Clean Air Act

to promulgate, implement and enforce a

measure, and must not be preempted

from promulgating, implementing, or

enforcing it by other federal statutes,

regulations or court orders before it

considers a measure reasonably

available. EPA’s FIP authority under

CAA section 110(c) is broad (see section

II.A.3. above); however, the Agency is

constrained in specific instances by the

Act itself. See e.g., CAA section

110(a)(5)(A)(i) (prohibition on indirect

source review programs) and section

110(c)(2)(B) (prohibition on parking

surcharges).

Additionally, EPA’s authority to

promulgate measures in a FIP which

would require the State to enact

legislation or expend state funds is

limited. EPA may require the State to

enact legislation or expend its funds if

the FIP measures affect the pollutioncreating activities of the State, but may

not do so if the effect is to govern the

pollution-creating activities of others.

For example, EPA could not require a

state to expand a mass transit system in

order to reduce emissions from private

automobiles. EPA could, however,

require a state to retrofit state-owned

buses to reduce emissions from those

buses. For a detailed discussion of this

issue, see 52 FR 23263, 23291–23292

(February 5, 1994) (proposed ozone and

CO FIP for the South Coast Air Basin).

4. Application of Federal

Implementation Criteria

Table 1 provides an overview of the

application of the above federal

implementation criteria to the 99

measures. Table 1 also identifies which

measures EPA has already approved as

RACM or has already promulgated a

federal measure that it considers RACM

(e.g., diesel fuel standards). Of the 99

measures, 21 were eliminated because

the sources do not exist in the Phoenix

area or the measure does not

beneficially affect PM–10 emissions, 11

because EPA had already approved or

promulgated RACM, and 11 measures

because EPA does not have the legal

authority to adopt and/or implement the

measure. Consequently, 56 measures

were considered for inclusion in the

proposed FIP. A more detailed

discussion of EPA’s reasons for rejecting

a measure can be found in the Technical

Support Document for today’s proposed

action.

In order to evaluate its ability to

implement each of these measures, EPA

had to first identify how it would

implement the measure. EPA

considered three basic methods of

implementation: (1) by rule requiring

the owner/operator of the source to

implement the control, (2) by direct

action (e.g., EPA would pave a road), or

(3) by providing additional funding to

the State or local agency to implement

the measure (e.g., expand MAG

ridesharing). The implementation

method(s) assumed for a measure is

indicated in Table 1 by the number in

parentheses after the description of the

measure. These numbers correspond to

the numbers above.

Note: Where a measure is not applicable to

the Phoenix area or where the Agency lacks

legal authority, EPA has not analyzed the

measure for the remaining criteria. This is

indicated by dashes in a column. A question

mark in a legal authority column indicates

that EPA’s legal authority is uncertain at this

time; however, for the purposes of this

analysis, question marks are treated as yeses.

TABLE 1.—MEASURES APPROPRIATE FOR FEDERAL IMPLEMENTATION

Source category and measure

Appropriate

to PHX

PM–10

No approved

RACM

Legal authorization

Available

federal

measures

A.1. Paved Road Dust—Reduce Dust (Silt) Loading

1. Pave, vegetate, or chemically stabilize access points where unpaved traffic surfaces adjoin paved roads (1) ........................................................................................ Y Y Y Y

2. Require haul trucks to be covered (1) ......................................................................... Y Y Y Y

3. Provide for traffic rerouting/rapid clean-up of temporary sources of dust (water erosion, track out, material spills) (1) ................................................................................ Y Y/N Y Y

4. Improved material specification for deicing materials (1) ............................................ N .................... .................... N

5 Require curbing and pave or stabilize road shoulders (1) ........................................... Y Y ? Y

6. Provide for stormwater drainage to prevent water erosion onto paved roads (2/3) ... Y Y ? Y

7. Mitigation of freeway construction impacts (1) ............................................................ Y Y/N Y Y

A.2. Paved Road Dust/Tailpipe Emissions—Reduce VMT

1. Implement short range transit improvements (2/3) ...................................................... Y Y ? Y

2. Implement long range transit improvements (2/3) ....................................................... Y Y ? Y
15930 Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules

TABLE 1.—MEASURES APPROPRIATE FOR FEDERAL IMPLEMENTATION—Continued

Source category and measure

Appropriate

to PHX

PM–10

No approved

RACM

Legal authorization

Available

federal

measures

3. Require exclusive bus lanes on arterials and freeways (2/3) ...................................... Y Y ? Y

4. Expand MAG rideshare program (2/3) ......................................................................... Y Y Y Y

5. Adopt trip reduction ordinance ..................................................................................... Y Y Y Y

6. Establish voluntary no drive days (2/3) ........................................................................ Y Y Y Y

7. Establish an areawide public awareness program (2/3) .............................................. Y Y Y Y

8. Build/establish park and ride lots (2/3) ........................................................................ Y Y Y Y

9. Provide employees financial incentives (e.g., zero bus fares) in lieu of parking (1) ... Y Y Y Y

10. Require employers to provide preferential parking for car and van pools (1) ........... Y Y Y Y

11. Require mandatory parking charges for employees (1) ............................................ .................... .................... N N

12. Build HOV lanes on freeways (3) .............................................................................. Y Y ? Y

13. Build HOV lanes on arterials (3) ................................................................................ Y Y ? Y

14. Build HOV ramps which bypass metering signals (3) ............................................... Y Y ? Y

15. Promote increased bicycle use (3) ............................................................................ Y Y Y Y

16. Provide or require bicycle travel (e.g., lanes) and support facilities (e.g., lockers

and racks) (3) ................................................................................................................ Y Y ? Y

17. Promote pedestrian travel through provisions of pedestrian facilities (e.g. sidewalks) (3) ...................................................................................................................... Y Y ? Y

18. Provide pedestrian overpasses (3) ............................................................................ Y Y ? Y

19. Promote the use of/require employers to provide alternative work hours (1) ........... Y Y Y Y

20. Promote the use of/require employers to provide alternative work weeks (1) .......... Y Y Y Y

21. Promote the use of telecommuting (1) ...................................................................... Y Y Y Y

22. Promote the use of teleconferencing (1/2/3) ............................................................. Y Y Y Y

23. Provide auto free zones and pedestrian malls (2/3) .................................................. Y Y N N

24. Provide vanpool purchase incentives such as tax breaks (1) ................................... Y Y N N

25. Require merchants to provide alternative transportation incentives to customers

(1) .................................................................................................................................. Y Y Y Y

26. Implement congestion pricing (2/3) ............................................................................ Y Y N N

27. Require non-employee parking to be priced (1) ........................................................ Y Y N N

28. Impose fee on vehicles related to emissions (smog fees) (1) ................................... Y Y Y Y

29. Encourage private sector transit by state deregulation (1) ........................................ N .................... .................... N

30. Evaluate & mitigate air quality impacts from new development (indirect source review) (1) ........................................................................................................................ Y Y N N

31. Require increased land use density along transit routes (1) ..................................... Y Y N N

32. Provide a fee-based tradable travel permit program (1/2) ........................................ Y Y N N

33. Set up system of road pricing (2/3) ........................................................................... Y Y N N

B. On-Road Vehicle Exhaust—Tailpipe and Non-VMT Reduction Measures

1. Expand current I/M to all model years (1/2/3) ............................................................. Y Y Y Y

2. Expand the current I/M program statewide (1/2/3) ...................................................... Y Y Y Y

3. Expand the current I/M program countywide (1/2/3) ................................................... Y Y Y Y

4. Require the use of No. 1 diesel fuel (1) ...................................................................... Y N Y N

5. Require clean fuels for fleet vehicles (1) ..................................................................... Y Y Y Y

6. CA new car standards (1) ............................................................................................ Y Y Y Y

7. Reduce cold start emissions (1) .................................................................................. N .................... .................... N

8. Scrap higher polluting vehicles (2/3) ............................................................................ Y Y Y Y

9. Reduce idling at drive up facilities (1) .......................................................................... N .................... .................... N

10. More strictly enforce traffic, parking, air pollution regulations (2) 1 ........................... Y Y N N

11. Freeway surveillance (2/3) ......................................................................................... N .................... .................... N

12. Ramp metering & signage (2/3) ................................................................................. N .................... .................... N

13. Traffic signal synchronization (1/2/3) ......................................................................... N .................... .................... N

14. Reversible lanes on arterials (1/2/3) .......................................................................... N .................... .................... N

15. One way streets (1/2/3) .............................................................................................. N .................... .................... N

16. Truck restrictions during peak periods (1/2/3) ........................................................... N .................... .................... N

17. Intersection improvements (2/3) ................................................................................. N .................... .................... N

18. On street parking restrictions (1/2/3) ......................................................................... N .................... .................... N

19. Bus pullouts in curbs (1/2/3) ...................................................................................... N .................... .................... N

20. Alternative fuels for buses/electric shuttle buses (1) ................................................. Y Y Y Y

21. Emission controls on public diesel vehicles (1) ......................................................... Y N .................... N

C. Dust from Unpaved Road/Parking Lot/Disturbed Vacant Lots

1. Pave or otherwise stabilize permanent unpaved haul roads, and parking or staging

areas at commercial, municipal, or industrial facilities (1) ........................................... Y N .................... N

2. Require sources to submit dust control plans (1) ........................................................ Y 2 N/Y Y Y

3. Develop traffic reduction plans on unpaved roads (1) ................................................. Y Y Y Y

4. Limit use of recreational vehicles on open land (1) ..................................................... Y Y Y Y

5. Pave or stabilize unpaved roads (1) ............................................................................ Y Y Y Y

6. Pave or stabilize unpaved parking areas (1) ............................................................... Y Y Y Y

7. Require controls on material storage piles (1) ............................................................. Y N .................... N
Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules 15931

TABLE 1.—MEASURES APPROPRIATE FOR FEDERAL IMPLEMENTATION—Continued

Source category and measure

Appropriate

to PHX

PM–10

No approved

RACM

Legal authorization

Available

federal

measures

8. Require stabilization of wind erodible soils (1) ............................................................ Y Y Y Y

9. Require windbreaks, watering, paving, vegetating for windblown dust (1) ................. Y Y Y Y

10. Restrict blowers for landscaping (1) .......................................................................... Y Y Y Y

D. Agricultural Sources

1. Rely on soil conservation requirements (e.g., conservation plans) of the Food Security Act (1) ..................................................................................................................... Y Y Y Y

2. Require windbreaks for agricultural sources (1) .......................................................... Y Y Y Y

E. Residential Wood Combustion (RWC)

1. Establish an episodic curtailment program for RWC (1/2/3) ....................................... Y N .................... N

2. Establish a public education/information program for RWC (2/3) ............................... Y N .................... N

3. Encourage the improved performance of RWC devices (1) ........................................ Y N .................... N

4. Provide inducements to reduce number of RWC devices (1/2/3) ............................... Y N .................... N

F. Other Area Sources

1. Develop a smoke management program for prescribed burns (1) ............................. Y N .................... N

G. Point Sources

1. RACT for stationary sources (1) .................................................................................. Y N .................... N

H. Marine Vessel/Ports

1. Divert port related truck traffic to rail (1) ...................................................................... N .................... .................... N

2. Control emissions from ship berthing facilities (1) ....................................................... N .................... .................... N

3. Control fugitive emissions from marine vessels (1) ..................................................... N .................... .................... N

4. Control emissions from marine diesel operations (1) .................................................. N .................... .................... N

5. Limit the sulfur content of marine fuel (1) .................................................................... N .................... .................... N

I. Locomotives

1. Reduce rail crossings (1) ............................................................................................. Y Y N N

2. Control switching locomotives (1) ................................................................................ Y Y Y Y

3. Electrify rail lines (1) ..................................................................................................... Y Y Y Y

J. Airplanes/Airport Ground Equipment

1. Centralized airport ground power systems (1) ............................................................. Y Y Y Y

2. Reduce emissions from airport ground access vehicles (1) ........................................ Y Y Y Y

3. Establish tighter emissions standards for new jet engines (1) .................................... Y Y Y Y

4. Control emissions from aircraft and ground service vehicles (1) ................................ Y Y Y Y

5. Require replacement of high emitting aircraft (1) ........................................................ Y Y Y Y

6. Require general aviation vapor recovery (1) ............................................................... N .................... .................... N

K. Other Non-Road Engines

1. Establish emission standards for small utility equipment (1) ....................................... Y N .................... N

2. Establish emission standards for new heavy duty construction equipment (1) .......... Y Y .................... Y

3. Establish emission standards for off road motorcycles (1) .......................................... Y Y Y Y

L. Miscellaneous Measures

1. Expand PM–10 monitoring network (2⁄3) ...................................................................... N .................... .................... N

2. Move state fair to a different time of the year (1) ........................................................ N .................... .................... N

3. Winter daylight savings time (1) ................................................................................... N .................... .................... N

1EPA has no legal authority to enforce local measures, such as traffic and parking regulations, which are not approved into the SIP. Most PM–

10 air pollution regulations are separately listed in this table. 2 Dust control plans are a requirement for sources which are required to obtain a permit from the County, but are not a requirement for

unpermitted sources. A dust control plan is a method for identifying, implementing and enforcing dust control measures for and on a particular

source, rather than a dust control measure in and of itself.

5. RACM Criteria

The General Preamble suggests three

criteria for excluding measures as

RACM: de minimis source,

technological infeasibility, and the cost

of control in the nonattainment area.

EPA’s proposed definitions for each of

these criteria are described below.

a. De Minimis Source. EPA proposes

to rely on the criteria applied under its

new source permitting programs (40

CFR 51.165(b)) as a guide in

determining when a source category is

de minimis for the purposes of

determining whether RACM must be

applied: a de minimis source or source

category is one that contributes less than
15932 Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules

22–24This de minimis RACM criterion is invoked

here solely for the purposes of determining which

source categories need RACM and not for

determining which source categories need controls

for attainment. See Section IV.B.

25EPA has already approved RACM for some of

the de minimis sources, e.g., major stationary

sources, residential wood combustion, non-road

engines). Also, EPA notes that some de minimis

source categories already have substantial SIPapproved controls on them (e.g., clean fuels and

inspection and maintenance program for on-road

mobile sources) although EPA has not formally

found these controls to be RACM under the

moderate area PM–10 RACM requirement in section

189(a)(1)(C).

5 g/μ3 of PM–10 to a location of

expected 24-hour exceedances and 1 μg/

m3 to a location of expected annual

violation. To be a considered a de

minimis source for the purposes of this

RACM analysis, the source had to be de

minimis for both the 24-hour and

annual standard. As discussed

previously in section IV.B., focusing on

what is reasonable and practicable for

significant sources is consistent with the

CAA’s scheme of graduated controls for

PM.

EPA has used the results from the

State’s microscale plan to identify

which source categories are significant

and de minimis for the 24-hour standard

for the purposes of RACM analysis. As

discussed in EPA’s final action on the

microscale plan (62 FR 41856), the

significant source categories for the 24-

hour standard are unpaved roads,

unpaved parking lots, disturbed cleared

areas (i.e., vacant lots), agricultural

fields, and agricultural aprons. 62 FR

31031. De minimis source categories for

the 24-hour standard are industrial

yards, surface mining, other industrial

activities, paved roads, trackout, and

paved parking lots. To determine significant and de

minimis sources for the annual standard

for this RACM analysis, EPA has relied

on the results at the Greenwood

monitoring site in the State’s Urban

Airshed Model (UAM) simulation,

performed as part of ongoing work for

Maricopa’s serious area PM–10 plan, see

MAG Modeling TSD, Table 6.9. The

complete list of significant and de

minimis sources for this RACM

determination can be found in Table 2

below. Where the air quality modeling

provides only a single impact number

for a group of source categories (e.g.,

‘‘other area sources’’ which contains

area source fuel combustion, open

burning, and emissions from

charbroiling), EPA has assumed that the

impact of an individual source category

is proportional to its presence in the

inventory for that group of source

categories. In total, the de minimis

categories account for less than 10

percent of the total exceedance value at

the Greenwood monitor.22–24, 25

TABLE 2.—SIGNIFICANT AND DE MINIMIS SOURCE CATEGORIES FOR DETERMINING RACM FOR THE ANNUAL STANDARD

PM–10 Source category

Annual impact at the

Greenwood

Monitor (μg/

m 3)

Significant Source Categories

Paved road dust ...................................................................................................................................................................................... 20.0

Unpaved road dust .................................................................................................................................................................................. 2.9

Construction/earthmoving ........................................................................................................................................................................ 5.4

Non-road engines .................................................................................................................................................................................... 1.2

De Minimis Source Categories

On-road mobile sources:

Gasoline-powered ............................................................................................................................................................................. 0.3

Diesel-powered ................................................................................................................................................................................. 0.9

Agricultural dust ....................................................................................................................................................................................... 0.2

Residential wood combustion .................................................................................................................................................................. 0.4

Other area sources:

Fuel combustion ............................................................................................................................................................................... 0.4

Charbroiling ...................................................................................................................................................................................... 0.5

Other ................................................................................................................................................................................................. 0.5

Other non-road engines:

Locomotives ...................................................................................................................................................................................... 0.1

Airport ground support ...................................................................................................................................................................... 0.1

Major Point Sources ................................................................................................................................................................................ 0.2

Windblown dust ....................................................................................................................................................................................... 0.4

b. Technological Feasibility. As the

term is proposed to be used here,

technological feasibility means that the

control measure is currently available

and being implemented elsewhere and

that the measure can achieve PM–10

emission reductions in Maricopa

County prior to the attainment deadline

of December 31, 2001. EPA has long

held that it would not consider a

measure ‘‘reasonable’’ if it could not be

implemented on a schedule that would

advance the date for attainment in the

area. See 57 FR 13498, 13560.

For some measures (e.g., trip

reduction ordinances), the State has

already implemented SIP-approved

controls. For these measures, EPA has

evaluated the potential emission

reduction benefit of additional federal

controls from a baseline that reflects the

existing controls.

Finally, one measure on the list,

restrictions on blowers for landscaping,

would in order to be effective require a

complete ban on leaf blowers. EPA does

not believe that, under the CAA’s

graduated level of controls for PM–10,

that eliminating a source completely

constitutes a reasonable level of control.

c. Cost of Implementation. In

considering the cost of implementing a

measure in an area, the General

Preamble suggests that in case of public

sector sources and control measures, the

cost evaluation should consider the

impact of the reasonableness of the

measures on the governmental entity

that must bear the responsibility for

their implementation. 57 FR 13541. This

statement in the General Preamble is a

recognition, as noted in section IV.B.,
Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules 15933

26One significant source category for the annual

standard, paved roads, is not currently being

addressed comprehensively through SIP-approved

RACM or proposed FIP RACM. While EPA analyzed

40 potential measures for this source category (see

categories A.1. and A.2. on Table 1), only one of

these measures was found to be a FIP RACM. EPA

notes, however, that the State has a number of SIPapproved measures already in place, including a

trip reduction program, that reduce emissions from

this category.

that the regulatory scheme for PM–10 in

subpart 4 establishes two graduated

levels of control, RACM and BACM,

depending on the severity of the air

quality problem. As such, greater

latitude is given responsible entities to

determine what is feasible and

practicable when selecting their initial

RACM control strategy. Thus the nature

and scope of a potential control

measure, including such factors as the

degree of capital expenditures required

and lead-time needed for legislative

consideration, operational and/or

infrastructural development needs, etc.,

are appropriate determinants of what

measures may be ‘‘reasonably

available.’’

In promulgating a FIP, EPA is the

primary implementing entity. As such,

EPA must evaluate the reasonableness

of potential RACM based on its financial

and resource capabilities (in the manner

described above for other governmental

entities) to implement the measure . The

Agency notes that its duty to promulgate

and implement FIPs is in addition to

rather than a replacement of its other

duties under the Clean Air Act. As such,

where implementing a potental RACM

FIP measure would require the Agency

to expend substantial efforts to acquire

needed resources, including financial

resources, EPA could also take such

factors into consideration in

determining whether the measure is

practicable and, thus, reasonable to

implement.

A general discussion of the abovedescribed types of constraints in

implementing measures for the Phoenix

area can be found in the 1990 CO FIP

proposal. 55 FR 41210. While EPA may

undertake the necessary steps to acquire

resources and funding, e.g., by diverting

personnel and funds or by submitting

budget supplement requests to

Congress, to implement and enforce a

FIP in Maricopa County or anywhere

else in the nation, the feasibility of such

efforts, depending on the nature and

scope of the work needed to implement

the proposed measure, may well exceed

what may fairly be considered

reasonable or practicable. EPA has also

discussed generally the resource

constraints associated with federal

implementation of transportation

control measures in its proposal of an

ozone and CO FIP for the Los Angeles

area. See 55 FR 36458, 36517

(September 5, 1990).

Examples of measures on the list that

are generally not reasonably within

EPA’s current resource constraints to

implement are measures which require

substantial capital or operational

expenditures. Examples of measures in

this category include building high

occupancy vehicle lanes, funding

expansion of mass transit, and

constructing substantial traffic flow

improvements.

6. Application of RACM Criteria

EPA applied these proposed RACM

criteria to the 56 measures in Table 1

that were found to be appropriate for

federal implementation. The results of

this RACM screening are given in Table

3. Of the 56 measures, 46 were

eliminated: 17 because they apply to de

minimis sources; 20 because a federal

measure would not improve on the

emission reduction benefit from a SIPapproved measure; 5 because the

measure could not be feasibly

implemented prior to the attainment

date, one because the measure required

elimination of the source completely

which EPA believes is unreasonable,

and 3 because of cost considerations. A

more detailed discussion of EPA’s

justifications for rejecting potential

RACM measures based on these RACM

criteria can be found in the TSD for this

proposed rulemaking.

As seen from Table 3, ten measures

remain after the application of the

RACM criteria. These measures are a

variety of potential fugitive dust

controls for unpaved roads, unpaved

parking lots, disturbed cleared land, and

agriculture. Therefore, as described in

detail in section V.A.7, EPA is

proposing federal RACM measures to

address these fugitive dust sources

including a federal fugitive dust rule

and an enforceable commitment for the

agricultural sector.26

TABLE 3.—FIP RACM EVALUATION 1

Source category and measure De Minim is

Source

Technically

feasible

Reasonable

implementation costFIP RACM

A.1. Paved Road Dust—Reduce Dust (Silt) Loading

1. Pave, vegetate, or chemically stabilize access points where unpaved traffic surfaces adjoin paved roads (1) ........................................................................................ N Y Y Y

2. Require haul trucks to be covered (1) ......................................................................... Unk 2 N–1 .................... N

3. Provide for traffic rerouting/rapid clean-up of temporary sources of dust (water erosion, track out, material spills) (1) ................................................................................ Unk N–1 .................... N

5. Require curbing and pave or stabilize road shoulders (1) .......................................... Unk N–1 .................... N

6. Provide for stormwater drainage to prevent water erosion onto paved roads (2/3) ... N N–1 N N

7. Mitigation of freeway construction impacts (1) ............................................................ Unk N–1 .................... N

A.2. Paved Road Dust/Tailpipe Emissions—Reduce VMT

1. Implement short range transit improvements (2/3) ...................................................... N Y N N

2. Implement long range transit improvements (2/3) ....................................................... N N–2 N N

3. Require exclusive bus lanes on arterials and freeways (2/3) ...................................... N N–2 N N

4. Expand MAG rideshare program (2/3) ......................................................................... N Y N N

5. Adopt trip reduction ordinance (1) ............................................................................... N N–1 .................... N

6. Establish a voluntary no drive days (1) ....................................................................... N N–1 .................... N

7. Establish an areawide public awareness program (1) ................................................. N N–1 .................... N

8. Build/establish park and ride lots ................................................................................. N N–1 N N

9. Provide employees financial incentives (e.g., zero bus fares) in lieu of parking (1) ... N N–1 .................... N
15934 Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules

TABLE 3.—FIP RACM EVALUATION 1—Continued

Source category and measure De Minim is

Source

Technically

feasible

Reasonable

implementation costFIP RACM

10. Require employers to provide preferential parking for car and van pools (1) ........... N N–1 .................... N

12. Build HOV lanes on freeways (3) .............................................................................. N N–1 N N

13. Build HOV lanes on arterials (3) ................................................................................ N N–2 N N

14. Build HOV ramps which bypass metering signals (3) ............................................... N N–1 N N

15. Promote increased bicycle use (3) ............................................................................ N N–1 N N

16. Provide or require bicycle travel (e.g., lanes) and support facilities (e.g., lockers

and racks) (3) ................................................................................................................ N N–1 N N

17. Promote pedestrian travel through provisions of pedestrian facilities (e.g. sidewalks) (3) ...................................................................................................................... N N–1 N N

18. Provide pedestrian overpasses (3) ............................................................................ N N–1 N N

19. Promote the use of/require employers to provide alternative work hours (1) ........... N N–1 .................... N

20. Promote the use of/require employers to provide alternative work weeks (1) .......... N N–1 .................... N

21. Promote the use of telecommuting (1) ...................................................................... N N–1 .................... N

22. Promote the use of teleconferencing (1/2/3) ............................................................. N N–1 .................... N

25. Require merchant to provide alternative transportation incentives to customers (1) N N–2 .................... N

28. Impose fee on vehicles related to emissions (smog fees) (1) ................................... N N–2 .................... N

B. On-Road Vehicle Exhaust—Tailpipe and Non-VMT Reduction Measures

1. Expand current I/M to all model years (1/2/3) ............................................................. Y .................... .................... N

2. Expand the current I/M program state wide (1/2/3) ..................................................... Y .................... .................... N

3. Expand the current I/M program county wide .............................................................. Y .................... .................... N

5. Require clean fuels for fleet vehicles ........................................................................... Y .................... .................... N

6. CA new car standards .................................................................................................. Y .................... .................... N

8. Scrap higher polluting vehicles (2/3) ............................................................................ Y .................... .................... N

20. Alternative fuels for buses/electric shuttle buses (1) ................................................. Y .................... .................... N

21. Emission controls on public diesel vehicles (1) ......................................................... Y .................... .................... N

C. Dust from Unpaved Road/Parking Lot/Disturbed Vacant Lots

2. Require sources to submit dust control plans (1) ........................................................ N Y Y Y

3. Develop traffic reduction plans on unpaved roads (1) ................................................. N Y Y Y

4. Limit use of recreational vehicles on open land (1) ..................................................... N Y Y Y

5. Pave or stabilize unpaved roads (1) ............................................................................ N Y Y Y

6. Pave or stabilize unpaved parking areas (1) ............................................................... N Y Y Y

8. Require stabilization of wind erodible soils (1) ............................................................ N Y Y Y

9. Require windbreaks, watering, paving, vegetating for windblown dust (1) ................. N Y Y Y

10. Restrict blowers for landscaping (1) .......................................................................... Unk. N–3 .................... N

D. Agricultural Sources

1. Rely on soil conservation requirements (e.g., conservation plans) of the Food Security Act (1) ..................................................................................................................... N Y Y Y

2. Require windbreaks for agricultural sources (1) .......................................................... N Y Y Y

I. Locomotives

2. Control switching locomotives (1) ................................................................................ Y .................... .................... N

3. Require electrification of rail lines (1) .......................................................................... Y .................... .................... N

J. Airplanes/Airport Ground Equipment

1. Centralized airport ground power systems (1) ............................................................. Y .................... .................... N

2. Reduce emissions from airport ground access vehicles (1) ........................................ Y .................... .................... N

3. Establish tighter emissions standards for new jet engines (1) .................................... Y .................... .................... N

4. Control emissions from aircraft and ground service vehicles (1) ................................ Y .................... .................... N

5. Require replacement of high emitting aircraft (1) ........................................................ Y .................... .................... N

K. Other Non-Road Engines

2. Establish emission standards for new heavy duty construction equipment (1) .......... Y .................... .................... N

3. Establish emission standards for off-road motorcycles (1) .......................................... Y .................... .................... N

1Technological feasibility codes on Table 3 are:

N–1. Measure is already in place in local jurisdiction. Additional federal rule would not result in additional emission reductions.

N–2. Measure is very unlikely to result in measurable emission reductions in the Phoenix area because technology is not available and/or

demonstrated, technology will not be available prior to the attainment date, and/or supporting infrastructure is absent (e.g., a viable transit system

is necessary in order for merchant transportation incentives to be effective).

N–3. Measure involves elimination of the source and therefore does not represent a reasonable level of control.

2While paved (i.e., re-entrained) road dust is clearly a significant source of PM–10 in the Phoenix nonattainment area, the contribution of unpaved shoulders, material from haul trucks, all track out and accidental spills to this source category is unknown.
Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules 15935

27–29Application of Rule 310 to agricultural

sources including fields and aprons is affected by

a provision in section 102 of the rule which

incorporates A.R.S. 49–504.4. Section 102 provides

that Rule 310 ‘‘shall not be construed so as to

prevent normal farm cultural practices.’’ Therefore,

applicability of the rule to such sources depends on

the nature of the dust-generating operation. As

such, Rule 310 applies to some operations on

agricultural fields and aprons and not to others.

30 In addition to EPA’s standard AP–42 emission

methodologies and some other prior special studies

for particular source categories, the microscale

study included field surveys, aerial photography,

examination of activity logs, and interviews with

source operators. The study resulted in a

substantially better emissions inventory data than is

usually available.

31EPA identified South Coast Air Quality

Management District (SCAQMD) Rule 403.1—Wind

Entrainment of Fugitive Dust. This rule applies to

any activities which can generate fugitive dust

when winds exceed twenty-five miles per hour

(mph) in the Coachella Valley Planning PM–10

nonattainment area. Rule 403.1 requires that any

person involved in activities which both occur in

the Coachella Valley Blowsand Zone and are

capable of generating fugitive dust to stabilize

deposits using water or dust suppressants, or install

wind breaks, and also restricts agricultural tilling

when wind speeds exceed twenty-five mph and

requires that inactive disturbed surface areas be

stabilized using water or dust suppressants.

EPA also identified SCAQMD 403—Fugitive Dust

(amended February 14, 1997), which requires any

person generating fugitive dust from an active

operation, open storage pile, or disturbed surface to

implement RACM or BACM listed in the rule to

minimize fugitive dust (e.g., apply chemical

stabilizers on disturbed surface areas; apply water

to unstabilized areas three times per day). Subject

sources may submit a dust control plan in lieu of

the control measures listed in the rule.

Finally, EPA identified SCAQMD Rule 1186—

PM10 Emissions From Paved and Unpaved Roads,

and Livestock Operations, which is intended to

reduce PM–10 entrained in the ambient air as a

result of vehicular travel on paved and unpaved

roads, and at livestock operations. The

requirements affecting livestock operations include:

cease hay grinding between 2 and 5 p.m. if visible

emissions extend 50 feet from the source; and treat

unpaved access connections and unpaved feed

access areas using either pavement, gravel, or

asphalt.

A more detailed discussion of the provisions

found in these rules can be found in the Technical

Support Document for today’s proposed action.

32EPA recognizes the role of USDA’s Natural

Resources Conservation Service (NRCS) in working

with individual growers to voluntarily develop Soil

Conservation Plans (SCPs). Because SCPs in the

Maricopa County area are voluntary (approximately

one-third of the growers have a SCP), growerinitiated, and have very minimal air quality benefits

as currently designed, the use of SCPs in Maricopa

County was determined to not meet RACM and thus

not considered a viable option for the proposed FIP.

See 57 FR 13498, 13541. In addition,

representatives from NRCS and the Arizona Farm

Bureau Federation have indicated to EPA that they

do not support using SCPs for RACM.

a. Commitment for Agricultural

Sector. (1) Summary of Proposed

Commitment and Approach EPA’s

RACM analysis above indicates that

RACM controls are needed for

agricultural sources of PM–10.

Currently, RACM is not being fully

implemented for agricultural fields and

aprons in the Phoenix area.27–29

Therefore, federal measures are needed

to reduce PM–10 from these sources.

EPA is proposing an enforceable

commitment to adopt and implement

RACM as required by CAA section

189(a)(1)(C) for the agricultural sector.

In order to develop the RACM, as

discussed below, EPA intends to use a

stakeholder approach which, it is

anticipated, will result in the

development of best management

practices (BMPs) that provide PM–10

emission reductions from agricultural

sources in the nonattainment area.

(2) Background. The microscale

plan 30 demonstrated that wind-blown

dust from agricultural fields and aprons

(i.e., farm access roads and equipment

turnaround areas) significantly

contributes to exceedances of the 24-

hour standard at the Gilbert and West

Chandler monitoring sites. These sites

are representative of the numerous

agricultural-urban interface areas

located in the nonattainment area.

The Gilbert monitoring site is located

on the grounds of the City of Gilbert’s

wastewater treatment plant and has

agricultural fields and aprons to its

north, an unpaved and paved parking

lots to the north and west, and a city

park to the south. Modeling showed that

windblown dust from agricultural fields

and unpaved parking lots was the

largest contributor to the exceedance at

the Gilbert monitor. The West Chandler

monitoring site is bordered on the west

by agricultural fields and the right of

way for the Price Road/Freeway, which

was under construction in early 1995.

Modeling showed that windblown dust,

mainly from agricultural fields and road

construction, was the largest contributor

to the exceedance at the West Chandler

monitor.

There are approximately 600 growers

farming approximately 300,000 acres of

land in Maricopa County. An estimated

63 percent of the agricultural activity in

Maricopa County occurs within the

nonattainment area. Upland cotton

(112,000 acres), alfalfa (54,000 acres),

and durum wheat (45,000 acres)

comprised over two-thirds of the crop

acreage in Maricopa County during

1996. Cash receipts for crops grown in

1996 totaled over $440 million, ranking

Maricopa County second in the state.

The area is characterized by very low

rainfall (7 inches per year) and desert

conditions.

Maricopa County is undergoing rapid

urbanization with agricultural land

being converted into other uses at a rate

of approximately 6,000 acres per year.

As this urbanization continues, the

amount of PM–10 associated with

agricultural lands will decrease because

the amount of land being farmed within

Maricopa County is shrinking. The 1996

Farm Bill has also affected farming

practices in the Maricopa County

nonattainment area. See 16 U.S.C. 3801

et seq. After 1994, land which had been

set aside under a prior U.S. Department

of Agriculture (USDA) program was

placed in production (primarily alfalfa).

The switch from unplanted set-aside to

planted alfalfa resulted in a relatively

small decrease in PM–10 emissions.

Despite the conversion of agricultural

lands to other uses and the small

increase in agricultural land being put

back into production, agricultural

sources are expected to continue to

contribute to PM–10 emissions for the

foreseeable future.

(3) RACM Analysis. EPA evaluated

existing agriculture measures in the

South Coast Air Basin (SCAB) 31 to

assess potential RACM for agriculture

for the Phoenix nonattainment area.32

However, it is important to note that

because agricultural sources in the

United States vary by factors such as

regional climate, soil type, growing

season, crop type, water availability,

and relation to urban centers, each PM–

10 agricultural strategy is uniquely

based on local circumstances. Unlike

many stationary sources, which can

have many common design features,

whether located in California or New

Jersey, agricultural sources and

activities vary greatly throughout the

country.

With respect to Phoenix and the Los

Angeles area, EPA determined that the

two areas differ in a number of key

characteristics (e.g., crops grown, soil

types, climate, and number of growers

affected). In assessing RACM for

agricultural sources, EPA considered the

uniqueness of the myriad factors

affecting agricultural activity in the

nonattainment area. 57 FR 13498,

13540–13541. Based on this initial

screening, EPA decided that it would

not be responsible to propose the

SCAQMD rules at this time because the

Agency could not reasonably conclude

that their implementation would in fact

result in air quality benefits for the

nonattainment area. Instead, the

SCAQMD rules will be further assessed

as part of the BMP development

process. This process will allow EPA to

take advantage of various local and

national agricultural expertise to more

fully evaluate whether the SCAQMD

rules, portions thereof, or other unique

emission reduction strategies would

contribute to attainment and, therefore,

should be applied in Maricopa County.
15936 Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules

33 In early 1997, the USDA’s Agricultural Air

Quality Task Force began discussions with EPA on

issues related to agriculture and air quality. Over

the course of the year, the Task Force drafted a

Memorandum of Understanding (MOU) between

USDA and EPA that establishs a formal relationship

for sharing expertise and involving the agricultural

community in air quality issues. The MOU was

signed by EPA on February 25, 1998 and by the

USDA on 1/14/98. EPA believes that the BMP

approach follows the cooperative spirit outlined in

the MOU.

(4) Proposed Commitment

(i) Discussions With Stakeholders. In

recognition of the need to address

agriculture’s contribution to the PM–10

exceedences, the microscale plan

included a March 27, 1997 letter signed

by the Arizona Department of

Environmental Quality (ADEQ), MCESD

and the NRCS. The letter stated the

intent of the three agencies to work

cooperatively toward strategies that

address PM–10 emissions from

agricultural lands within Maricopa

County. The three agencies sponsored

meetings in March and May, 1997

which brought stakeholders together to

discuss agriculture and PM–10. At the

same time, and into the summer of

1997, MAG was working with the

Maricopa County Farm Bureau on

possible emission controls for

agricultural lands as part of the PM–10

serious area plan development. Also

during the summer of 1997, EPA held

meetings with ADEQ, MAG, MCESD,

and NRCS to discuss potential strategies

to reduce PM–10 from agricultural

lands.

Because there were two separate

ongoing efforts with respect to PM–10

emissions from agricultural sources, as

described above, EPA used these

meetings to keep apprised of the

progress of the two efforts, as well as to

discuss implementation issues related to

agricultural control measures. The MAG

discussions with the Maricopa Farm

Bureau resulted in the identification of

several potential PM–10 control

measures by early fall, 1997. These

measures were voted on and approved

by the Maricopa County Farm Bureau

Board in September, 1997. At that time,

EPA decided that a joint discussion

with ADEQ, MCSED, MAG, NRCS, and

the Farm Bureau would be beneficial to

both the FIP and SIP processes.

Thereafter, EPA contacted the NRCS,

the Arizona Farm Bureau Federation,

and other stakeholders and arranged for

a November 12–14, 1997 tour of

agricultural activities to better

understand their impact in Maricopa

County. Several meetings were held

with these same stakeholders. The

meetings provided an opportunity for

EPA to discuss the upcoming FIP

proposal and the need to work

collaboratively 33 on strategies

addressing agriculture and PM–10. The

tour and subsequent meetings allowed

EPA to work directly with the leaders in

the Maricopa County agricultural and

regulatory community and set the stage

for future discussions on possible

strategies for reducing PM–10 from

agriculture in the area. Subsequent

meetings on December 2 and 16, 1997

among EPA, Farm Bureau

representatives, farmers, NRCS, ADEQ,

MCESD, and MAG resulted in a general

consensus on using a BMP approach to

develop measures to reduce PM–10

from agriculture. On January 7, 1998,

EPA Region IX sent a letter to the

Maricopa County Farm Bureau stating

EPA’s intention to include the BMP

approach in the proposed FIP. On

January 21, 1998, the Maricopa County

Farm Bureau sent a letter to EPA Region

IX indicating their general support for

the BMP approach. The letter also

provided their recommendations on

milestones and timeframe needed for a

successful BMP approach.

(ii) BMP Approach. The proposed

BMP approach for addressing PM–10

from agricultural sources could be

modeled after an analogous BMP

approach used for managing fertilizer

applications and protecting

groundwater in Arizona. Under the

nitrogen fertilizer BMP program,

legislation was passed in the late 1980s

giving the Director of ADEQ the

authority to oversee the development

and implementation of BMPs. An

Advisory Committee, comprised of

representatives from key government

agencies, universities, and the

agricultural community was established

to develop and recommend BMPs for

adoption by ADEQ. After adoption of

the BMPs, supplemental guidance

documents were developed by the

University of Arizona to assist growers,

and an extensive grower education

campaign was undertaken to increase

the likelihood for successful BMP

implementation. The BMPs eventually

became part of the Arizona

Administrative Code (Title 18, Chapter

9, Article 2), which requires that all

persons engaged in the application of

nitrogen fertilizers be issued a general

permit and comply with the six

agricultural BMPs stated in the law. A

similar approach was also used to

develop BMPs for concentrated animal

feeding operations in Arizona.

(iii) FIP Proposal. EPA is proposing an

enforceable commitment to adopt and

implement RACM to reduce PM–10

emissions from agricultural sources. The

proposed FIP commitment includes a

series of enforceable milestones and due

dates listed in Table 4 to assure

adoption and implementation of RACM.

EPA would initially convene a

stakeholder-based process to begin

formal development of draft BMPs.

Stakeholder groups represented will

likely include but not be limited to the

Arizona Farm Bureau Federation,

Maricopa County Farm Bureau, ADEQ,

MAG, MCESD, NRCS, Cooperative

Extension, the University of Arizona,

tribes, and environmental and/or public

health organizations. This effort would

build upon the stakeholder-based

discussions which occurred in 1997 and

early 1998. By September 1998, the

stakeholders would begin to draft BMPs.

Potential BMPs likely to be considered

include but are not limited to:

windbreaks, vegetative covers, chemical

or physical soil stabilizers, improved

tillage practices, tillage limitations

during high wind events, speed

reductions on unpaved or untreated

farm roads, and tillage pre-irrigation.

The milestones by which EPA proposes

to complete various aspects of BMP

development and implementation are as

follows. By September 1999, EPA will

have drafted the BMPs developed for

official public comment, which will

occur through a Notice of Proposed

Rulemaking. After public comment and

additional stakeholder meetings, EPA

will finalize the BMPs in a Notice of

Final Rulemaking. In June 2000, BMP

implementation will begin with an

extensive collaborative public outreach

and education campaign. Guidance

documents would be developed to assist

growers with implementation of the

BMPs. Compliance assistance would

also be a key element of the BMP

program.

TABLE 4.—PROPOSED DEADLINES FOR EPA ADOPTION/IMPLEMENTATION OF RACM FOR AGRICULTURE IN MARICOPA

Milestones Due date

Notice of Proposed Rulemaking for RACM .................................................................................................................................... September 1999.

Notice of Final Rulemaking for RACM ........................................................................................................................................... April 2000.
Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules 15937

34Rule 310 only requires recordkeeping for

permitted dust-generating operations.

TABLE 4.—PROPOSED DEADLINES FOR EPA ADOPTION/IMPLEMENTATION OF RACM FOR AGRICULTURE IN MARICOPA—

Continued

Milestones Due date

RACM implementation .................................................................................................................................................................... June 2000.

(5) FIP Replacement.

Although EPA is only required in the

FIP to meet the CAA RACM

requirement, the State is expected, as

required for PM–10 serious

nonattainment areas, to develop BACM

for agricultural sources. The State

expects the BACM developed for the

serious area plan to also Satisfy any

remaining CAA RACM requirements.

EPA is committed to working with

ADEQ and the other stakeholders to

develop a SIP measure to replace the

proposed enforceable commitment.

While EPA’s intended BMP approach

is designed to meet the RACM

requirement, the Agency believes it can

serve as a potential starting point and

model for the development of a Stateled SIP process for addressing BACM for

agricultural sources. Thus, the

stakeholders could potentially build

upon the BMP approach initiated for the

FIP to address both RACM and BACM

requirements for the agricultural sector

in the SIP. The Arizona Farm Bureau

Federation, the Maricopa County Farm

Bureau, NRCS, ADEQ, and other

regulatory agencies are currently

working collaboratively to develop a

State-led BMP process for that purpose.

EPA strongly endorses such a process.

However, because EPA has not received

to date an adequate SIP submittal

addressing the implementation of

RACM by June 2000 for agricultural

sources of PM–10, EPA is proposing an

enforceable commitment for those

sources as described above.

b. Rule for Unpaved Parking Lots,

Unpaved Roads and Vacant Lots.

Fugitive dust from unpaved parking lots

and unpaved roads is primarily caused

by vehicle traffic. When vehicles travel

over unpaved surfaces, they raise the

silt content (i.e., grind up dirt so as to

result in a greater abundance of finer

particles). The more vehicles (and the

faster they travel) on unpaved surfaces,

the more PM–10 is stirred up in clouds

of fugitive dust.

On vacant lots, fugitive dust

emissions are caused by virtually any

activity which disturbs an otherwise

naturally stable parcel of land,

including earth-moving activities, weed

abatement, material dumping and

vehicle traffic. Once disturbed, the

vacant lot may continuously generate

dust until it is restabilized. Since wind

conditions affect the amount of dust

raised on vacant lots, PM–10 emission

impacts may not be fully realized until

several days following a disturbance.

MCESD’s Rule 310 requires RACM for

fugitive dust sources; however, EPA has

determined that the County does not

enforce the rule for three source

categories within the Phoenix PM–10

nonattainment area: unpaved parking

lots, unpaved roads and vacant lots. As

a result, EPA is having to fulfill the role

of primary enforcer of the RACM

requirement for these sources and has

developed its own proposed rule

addressing RACM for these sources.

EPA’s regional office in San

Francisco, California (EPA Region 9)

will have primary responsibility for

enforcement of the proposed FIP rule.

Given the difficulties that Region 9 will

inevitably face in enforcing the RACM

requirement in Arizona, EPA has

designed a RACM rule that ensures EPA

enforcement of the rule will be

practicable. Furthermore, EPA believes

that the proposed rule will be useful to

MCESD in future SIP efforts to control

dust from these sources.

In general, EPA believes that all of the

RACM requirements of the proposed FIP

rule can also be required through

enforcement of Rule 310. However, the

rule’s lack of specificity makes it more

likely that the agency enforcing the rule

will routinely be called upon to address

which RACM should be applied to

which source categories. By addressing

this issue in the FIP rule itself through

detailing specific RACM requirements,

EPA hopes to reduce the extent to

which sources and others may have to

consult with the Agency to determine

which RACM are appropriate for a

particular source or source category.

The only proposed FIP rule

requirement that is not required in Rule

310 is a recordkeeping requirement for

owners/operators to maintain records of

controls implemented on unpaved

roads, unpaved parking lots, and vacant

lots in order for EPA to ensure

compliance with the rule.34 The

proposed recordkeeping requirements in

the FIP rule are simple and

straightforward. In many cases, the

owner/operator need only retain a

purchase receipt or contractor work

order for the controls implemented.

More information is required when

chemical stabilization is applied as a

control measure, however, this

information is readily available from

vendors or easily determined at the time

of application.

(1) Summary of Proposed Rule. In

developing the proposed FIP rule, EPA

utilized the RACM in Rule 310 while

drawing upon several additional sources

to increase specificity of the measures.

A detailed discussion of EPA

determinations and references for the

proposed rule can be found in the

Technical Support Document. Specific

requirements of the proposed rule are

summarized below.

Unpaved parking lots: Any owners/

operators of unpaved parking lots

greater than 5,000 square feet are

required to pave, chemically stabilize,

or apply gravel to the lot within eight

months of the rule’s effective date. For

unpaved parking lots that are used no

more than 35 days per year, owners/

operators may choose to apply chemical

stabilizers within 20 days prior to any

day in which over 100 vehicles enter the

lot.

Unpaved roads: Any owners/

operators of existing public unpaved

roads with average daily trip volumes of

150 vehicles or greater are required to

pave, chemically stabilize, or apply

gravel to the unpaved road by June 10,

2000.

Vacant lots: (1) A Dust Control Plan

(as described in section 503) is required

for weed abatement operations on

vacant lots that disturb 0.10 acres or

more of soil by blading, disking,

plowing under or other means

(excluding mowing, cutting or similar

processes in which soil is not

disturbed), unless such operations

receive an approved permit from

Maricopa County Environmental

Services Department. (2) Any owners/

operators of an urban or suburban open

area vacant lot with 0.10 acres or more

of disturbed surface area which is

unused or undeveloped for more than

15 days are required to establish

vegetation, apply dust suppressants,

restore to a natural state, or apply gravel

to all disturbed surfaces within eight

months following the effective date of

the proposed rule or within eight

months following the initial 15 day
15938 Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules

35MCESD is currently preparing a revision to

Rule 310 which would require dust control plans

for weed abatement operations that disturb soil

surfaces of 0.1 acres or greater.

period of inactivity, whichever is later.

(3) Any owners/operators of an urban or

suburban open area vacant lot which

has a disturbed surface due to motor

vehicles (including off-road vehicles)

are required to place signs, fencing,

shrubs, trees, or cement barriers to

prohibit vehicle entry along the access

perimeter.

The threshold level of 0.10 acres for

weed abatement and disturbed surface

areas is the same threshold level for the

permitting of construction sites in Rule

310.35 Currently Rule 310 does not

contain a threshold exemption for

vacant lots. EPA is requesting comments

on whether the 0.1 acre threshold is the

appropriate threshold for determining

when controls on vacant lots is

required.

All categories: As an alternative to

compliance with any of the FIP rule

requirements (with the exception of the

weed abatement provision), owners/

operators may use alternative control

measures approved by EPA. Proposed

alternative control measures must be

submitted to EPA for approval prior to

the rule’s deadline for RACM

implementation for the source. Should

EPA disapprove an alternative control

measure, the owner/operator must begin

implementing RACM as required in the

rule no later than 60 days after receiving

notice of disapproval.

Recordkeeping: Owners/operators are

required to maintain records of controls

implemented on unpaved roads,

unpaved parking lots, and vacant lots.

(2) Discussion. The proposed FIP rule

includes three to four RACM options for

each source category. In order to ensure

that emission reductions are achieved,

the FIP rule only specifies control

measures which have a reasonably high

level of certainty in their control

effectiveness and enforcement.

However, EPA is willing to consider

other measures, and is therefore

allowing submittal of alternative control

measures for any of the source

categories subject to EPA approval.

Surveys of fugitive dust sources and

control measures are required to be

conducted by EPA or its contractor in

the proposed FIP rule in order to

improve knowledge of the universe of

sources and provide feedback on the

rule’s effectiveness. The surveys will

enable regulators to better estimate the

contribution of unpaved roads, unpaved

parking lots and vacant lots to Maricopa

County’s PM–10 inventory, identify

control measures that are the most

frequently implemented, and study the

effectiveness of these measures in

controlling fugitive dust.

Tests in order to determine

compliance with the proposed FIP rule

would be conducted by EPA or its

contractor, and do not pose additional

requirements on sources subject to the

rule. Implementation of some control

measures, such as paving unpaved

roads, are obvious upon inspection and

tests are not necessary to determine

compliance. For other control measures,

such as application of chemical

stabilizers and gravel, a test is needed to

determine whether the surface is

sufficiently stabilized to prevent or

minimize fugitive dust emissions.

For determining whether unpaved

roads and unpaved parking lots are

stabilized, EPA is proposing visible

opacity test methods associated with

vehicle use (Reference Method 9,

Methods 203A, 203B, and 203C), with

opacity readings conducted according to

203C. These methods incorporate a

fugitive dust element to Reference

Method 9, which is most appropriate for

measuring emissions from stationary

sources of PM–10. Method 203C allows

‘‘instantaneous’’ readings averaged over

a period of one minute, taken at 5

second intervals. EPA first proposed

Reference Method 9, Methods 203 A, B,

and C in 1993 (Appendix M, part 51)

and has incorporated public comments

into the test methods. While EPA has

not yet promulgated the methods, for

purposes of federal enforcement of the

FIP rule, they can be used as credible

evidence until such time as EPA

publishes a final rulemaking for the test

methods (40 CFR part 52.12).

For determining whether vacant lots

have stabilized surfaces, EPA is

proposing and requesting comment on

test methods concerning visible crusts,

vegetation, and threshold friction

velocity of soil samples. Information on

test methods proposed for this FIP is

available in the TSD and the rulemaking

docket.

The proposed FIP rule does not

preclude the right of any State or

locality to adopt or enforce an emission

standard or limitation which is more

stringent than this rule (Clean Air Act

section 116).

(3) Compliance Approach. Upon

promulgation of the FIP, EPA will

implement its rule for unpaved parking

lots, unpaved roads, and vacant lots.

Thus, EPA will take on responsibilities

that are normally performed by the local

air quality regulatory agency, in this

case, MCESD. These responsibilities

would include such activities as:

refining EPA’s information on the

universe of sources subject to the rule,

developing an outreach/compliance

assistance program for the affected

community, inspecting sources subject

to the rule, and following up with an

appropriate enforcement response in the

event of rule violations.

Although the cities in the Phoenix

area have provided information on the

sources within their jurisdictions, EPA

will be using contractual assistance to

obtain additional information on the

sources subject to the FIP rule. This

information will be used by EPA to

perform the surveys described above, to

evaluate the rule’s effectiveness, and to

identify sources for potential

inspections. This information can also

be used (and EPA will encourage its

use) by Maricopa County to better

implement Rule 310.

EPA will be implementing the FIP

rule by providing resources directly

from the Regional Office in San

Francisco. Working with the

information provided by the contractor,

Region 9 will develop a compliance

assistance strategy that will ensure that

sources subject to the FIP rule are

informed about the rule, and understand

how the rule applies to them, what their

compliance options are, and the need to

comply with the provisions in the rule.

Once EPA compliance assistance efforts

are underway, EPA will inspect these

sources for compliance with the FIP

rule.

In addition, EPA exercises a

traditional oversight role over state and

local air quality programs by making

periodic visits to the states within

Region 9 and conducting joint

inspections with the state and/or local

regulatory agencies. These joint

inspections can cover a variety of

sources, and, in the future, will include

sources covered by the FIP rule.

Also, because MCESD does not have

sufficient resources to enforce Rule 310

for unpaved roads, unpaved parking

lots, and vacant lots, EPA intends to

provide two additional inspection

resources to MCESD by supplementing

the MCESD CAA section 105 grant in

October 1998. These additional

inspectors will perform inspections for

EPA with respect to the three source

categories subject to the FIP Rule. These

additional resources will be provided to

MCESD as long as the FIP is in place.

(4) Replacement of FIP Rule. MCESD

is currently trying to obtain additional

resources to expand implementation of

Rule 310. If MCESD obtains the

additional resources and is able to

develop an enforcement strategy for the

vacant lot, unpaved parking lot and

unpaved road sources covered by the

FIP rule, this strategy may be submitted

to EPA for approval as meeting the
Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules 15939

36Estimated regional emission reductions from

the proposed FIP rule are discussed in Section

V.C.1.

CAA’s RACM requirement for these

sources. As part of any implementation

strategy that MCESD submits for EPA

approval, the County will need to

provide evidence that it has adequate

resources of its own to ensure that Rule

310 is fully enforced for all fugitive dust

sources. If approved, such a strategy

will allow EPA to rescind its FIP rule.

B. Impracticability Demonstration.

The Clean Air Act requires moderate

PM–10 nonattainment areas to

demonstrate attainment of the PM–10

annual and 24-hour standards, or to

show that attainment by December 31,

2001 is impracticable (see section IV.B.

of this notice). For this proposed FIP,

EPA is making the latter demonstration.

Based on modeling work performed by

the State, existing State controls

together with the RACM being proposed

by EPA are not sufficient for attainment

of either the 24-hour or the annual PM–

10 standard by December 31, 2001.

1. Annual Standard

For the annual standard attainment

analysis, EPA relied on the State’s

simulation of the 1995 year found in the

MAG Modeling TSD which was

performed as part of ongoing work for

Maricopa’s PM–10 serious area plan.

This work used a variant of the Urban

Airshed Model (UAM), which is the

EPA-recommended model for

attainment demonstrations for ozone

and carbon monoxide, though it can be

used to model any pollutant. The UAM

results were scaled using factors derived

from observed PM–10 concentrations

and from emissions projected to 2001.

Because the Greenwood monitoring site

had the highest simulated annual

concentrations, EPA has used this site

as the basis for the annual standard

impracticability demonstration.

As can be seen in Table 5, even

assuming 100 percent control for

sources subject to the proposed FIP rule

(an unrealistic level of control, actual

control levels will be less 36), simulated

concentrations are still over the annual

standard of 50 μg/m3. Thus, EPA

proposes to find that attainment of the

annual PM–10 standard is impracticable

with the implementation of RACM.

TABLE 5.—ANNUAL STANDARD IMPRACTICABILITY DEMONSTRATION

Source category

Concentration after

SIP controls

μg/m3

Maximum

possible

control (percent)

Concentration after

FIP controls

μg/m3

Paved road dust ....................................................................................................................................... 20.0 .................... 20.0

Unpaved road dust ................................................................................................................................... 2.9 100 0.0

Gasoline and Diesel vehicle exhaust ....................................................................................................... 1.2 .................... 1.2

Agricultural dust ........................................................................................................................................ 0.2 100 0.0

Other area sources .................................................................................................................................. 1.4 .................... 1.4

Residential wood combustion .................................................................................................................. 0.4 .................... 0.4

Construction/earth moving ....................................................................................................................... 5.4 .................... 5.4

Construction equipment, locomotives, other non-road engines .............................................................. 1.4 .................... 1.4

Major point sources .................................................................................................................................. 0.2 .................... 0.2

Windblown dust ........................................................................................................................................ 0.4 100 0.0

Anthropogenic Total ................................................................................................................................. 33.5 .................... 30.0

Background .............................................................................................................................................. 22 .................... 22

Total ............................................................................................................................................... 55.5 .................... 52.0

2. 24-hour Standard

For its 24-hour standard attainment

analysis, EPA relied on the modeling in

Arizona’s microscale plan. This

modeling used the ISCST (Industrial

Source Complex, Short Term) model, an

EPA guideline model often used for

stationary source permit applications,

and well-suited to the locally-driven

exceedances that were the focus of the

microscale plan. ISCST was used to

simulate PM–10 concentrations at

representative sites subject to emissions

from various source types and at which

24-hour exceedances had been

observed. These monitoring sites were:

1) Salt River, in an industrial area; 2)

Gilbert, affected by agricultural and

unpaved parking lot fugitive dust

emissions; 3) Maryvale, with disturbed

cleared areas nearby due to construction

of a park; and 4) West Chandler, near a

highway construction project. These

sites were selected to represent a variety

of conditions within the Maricopa

nonattainment area.

The microscale plan demonstrated

attainment at the Salt River and

Maryvale sites, and EPA approved the

attainment demonstrations at these sites

at the time it took final action on the

microscale plan. 62 FR 41856. The

microscale plan did not demonstrate

attainment at the West Chandler and

Gilbert sites. These sites will be

addressed here.

The proposed FIP rule requires RACM

for unpaved roads, vacant lots, and

unpaved parking lots. These sources in

total contribute 25 percent of the

emissions to the exceedance at the

Gilbert site and just 1 percent of the

emissions to the exceedance at the West

Chandler site. (For both sites, fugitive

dust from agricultural sources is the

largest contributor to the exceedances.)

The proposed FIP rule has a substantial

impact for the Gilbert site, reducing

ambient concentrations from 213 to 176

μg/m3 but much less effect at West

Chandler, reducing concentrations from

332 to just 316 μg/m3. See Table 6.

Because the proposed RACM do not

result in attainment at either site, EPA

is proposing to find that attainment of

the 24-hour standard is impracticable

with the implementation of RACM.

As can be seen from Table 6,

attainment at both sites will require

substantial reductions from agricultural

sources in addition to reductions from

unpaved roads, unpaved parking lots,

and vacant lots. While reductions from

agricultural sources are expected

through the implementation of BMPs by

2001, EPA is unable to quantify the

impact of these BMPs at this time

because they have not been defined

sufficiently to determine the expected

level of control. Once the BMPs have

been defined, EPA will better be able to

estimate reductions from agricultural

sources and will revisit any final

impracticability demonstration for the

24-hour standard and modify the

demonstrations as necessary.
15940 Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules

37The 1998 emission levels also include the

implementation of improved controls on

construction sources that were approved as BACM

in the microscale plan and were to be implemented

by mid-1997. No increase in control effectiveness

after 1998 is expected from these State BACM

measures or from other approved State RACM

measures; therefore, the RFP demonstration

proposed here only addresses the incremental

reductions resulting from the proposed FIP

measures.

TABLE 6.—IMPRACTICABILITY DEMONSTRATION FOR THE 24-HOUR PM–10 STANDARD

Source category

Concentration after SIP controls μg/m3 FIP control

(percent)

Concentration after FIP controls μg/m3

Chandler Gilbert Chandler Gilbert

Agricultural fields .............................................................................. 194.7 —— —— 194.7 ——

Agricultural aprons ............................................................................ 21.7 55.6 —— 21.7 55.6

Road construction ............................................................................. 6.9 —— —— 6.9 ——

Unpaved roads ................................................................................. 0.5 0.5 64 0.2 0.2

Paved Roads .................................................................................... 0.2 1.6 —— 0.2 1.6

Unpaved parking lots ........................................................................ ...................... 51.3 56 ...................... 22.6

Vacant lots ........................................................................................ 28.1 14.5 56 12.4 6.4

Anthropogenic Total .......................................................................... 252.1 123.4 .................... 236.1 86.3

Background ....................................................................................... 80 90 .................... 80 90

Total ........................................................................................... 332.1 213.4 .................... 316.1 176.3

See section V.C. immediately below

for a discussion of the estimated

emission reductions from the FIP

control measures.

C. Reasonable Further Progress (RFP)

Demonstration

As discussed previously in Section

IV.C. of this preamble, EPA interprets

the RFP requirement for areas

demonstrating impracticability as being

met by a showing that all RACM will be

implemented and that the

implementation of all RACM has

resulted in incremental emission

reductions below pre-implementation

levels. For the purposes of this proposed

RFP demonstration, pre-implementation

levels are 1998 emission levels, the

promulgation year for this FIP. Because

CAA section 171(1) defines RFP

reductions as being ‘‘for the purpose of

ensuring attainment* * *by the

applicable attainment date,’’ postimplementation levels are 2001

emission levels, the statutory attainment

year.37

RFP is demonstrated separately for

the annual and 24-hour standards

because the mix of sources contributing

to the annual standard exceedances

differs from that contributing to the 24-

hour exceedances. In addition, since

PM–10 exceedances are related almost

entirely to primarily-emitted PM–10,

only emissions of primarily-emitted

PM–10 are evaluated for RFP.

1. Annual Standard

The proposed RFP demonstration for

the annual standard is summarized here

and in Table 7. A complete discussion

of the RFP demonstration can be found

in the TSD for this proposed action.

Emission levels for 1998 and 2001

were calculated by growing emissions

from the emission inventory base year of

1994 and the modeling year of 1995

based on growth factors contained in the

MAG Modeling TSD and by

incorporating reductions from approved

State RACM and BACM controls.

Emissions levels for 2001 also reflect the

estimated emission reductions from the

proposed FIP rule for unpaved roads.

The estimated effectiveness of controls

on unpaved roads, 80 percent, was

based on the research done for the

microscale plan on the effectiveness of

controls for unpaved parking (see Table

4–1 in the final Microscale Plan) and

assumes a rule effectiveness of 80

percent per EPA’s guidance and that 90

percent of the VMT on unpaved roads

will be impacted by the FIP rule. 57 FR

13503.

The proposed annual RFP

demonstration does not include

emission reductions from the

implementation of the proposed FIP

rule for unpaved parking lots and vacant

lots. Although emission reductions are

expected from these sources, there

currently is insufficient information on

the number of unpaved parking lots and

vacant lots that will be subject to the FIP

to calculate an annual emission

reduction. Information from the surveys

EPA will perform after promulgation of

the rule will help in quantifying

emission reductions from these sources.

In addition, while reductions from

agricultural sources are also expected by

2001, no emission reductions were

assumed in the proposed RFP

demonstration for agricultural sources

because the ultimate RACM have not

been defined sufficiently to determine

the expected level of control.

As described in section V.A.7.b., the

FIP rule as proposed requires phased

implementation with final

implementation no later than June,

2000: existing vacant lots and unpaved

parking lots are required to comply

within 8 months of the effective date of

the final rule (approximately April

1999) and unpaved roads are required to

comply by June, 2000. Therefore, full

implementation of the measure by 2001

can be assumed. A more detailed

discussion of the proposed annual

standard RFP demonstration can be

found in the TSD for this action.

As can be seen from Table 7, the

emission reductions from the proposed

FIP measure for unpaved roads is

sufficient to assure an incremental

emission reduction between 1998 and

2001 and additional reductions

expected from unpaved parking lots,

vacant lots, and agricultural sources will

also contribute to this incremental

emission reduction; therefore, EPA

proposes to determine that the FIP

assures RFP for the annual standard.

TABLE 7.—RFP DEMONSTRATION FOR

THE ANNUAL STANDARD

Year

Total

PM–10

emissions

metric

tons/

year

1998 ................................................ 61,024

2001 ................................................ 54,256

2. 24-hour Standard

For the 24-hour standard, EPA

evaluated RFP only for the Gilbert and

West Chandler sites, having already

approved the RFP demonstrations at the

Maryvale and Salt River sites as part of

its action on the microscale plan. 62 FR

41856. For these proposed RFP

demonstrations, source activity at each

monitor was assumed to be unchanged
Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules 15941

38The microscale analysis at each monitor

evaluated sources in a very limited geographic area.

Because of this limited area, there is little

opportunity for sources to expand. In some cases,

a source that was present at the microscale site in

1995 no longer exists (e.g., the freeway construction

at the West Chandler site); however, for this

demonstration, EPA has assumed that the source is

still present since the sites were chosen to be

representative of other sites in the nonattainment

area.

from the 1995 levels determined in the

microscale plan.38

As with the annual standard

demonstration, 1998 emission levels

were adjusted to reflect implementation

of the improved controls on

construction sources and 2001

emissions levels to reflect the estimated

emission reductions from the proposed

FIP rule for unpaved roads, unpaved

parking lots, and vacant lots. Emission

reductions estimates are again based on

the research done for the microscale

plan and assume a rule effectiveness of

80 percent per EPA’s guidance. For

unpaved roads, a control effectiveness

of 80 percent is assumed. For vacant lots

and unpaved parking lots, a control

effectiveness of 70 percent is assumed.

As with the annual standard, no

emission reductions were assumed for

agricultural sources. A more detailed

analysis of the proposed RFP

demonstrations for the Gilbert and West

Chandler monitors can be found in the

TSD for this proposal.

a. Gilbert Monitoring Site. The 24-

hour exceedances at the Gilbert monitor

are impacted by emissions from

agricultural aprons, disturbed cleared

lands (i.e., vacant lots), unpaved parking

lots, and paved roads. 62 FR 31031. As

can be seen from Table 8, the emission

reductions from the proposed FIP rule

for unpaved parking lots and vacant lots

are sufficient to assure incremental

emission reductions between 1998 and

2001 at the Gilbert monitoring sites;

therefore, EPA proposes to determine

that the proposed FIP assures RFP for

the 24-hour standard at the Gilbert

monitor.

TABLE 8.—RFP DEMONSTRATION FOR THE 24-HOUR STANDARD—GILBERT MONITORING SITE

Source categories

1998 Emissions (kg/

day)

FIP Control

(percent)

2001 Emissions (kg/

day)

Agriculture aprons .................................................................................................................................. 165 0 165

Vacant lots .............................................................................................................................................. 76 0.56 33

Unpaved parking lots ............................................................................................................................. 190 0.56 84

Paved roads ........................................................................................................................................... 5 0 5

Total ............................................................................................................................................. 436 ...................... 287

b. West Chandler Monitoring Site.

The 24-hour exceedances at the West

Chandler monitor are impacted by

emissions from agricultural fields,

agricultural aprons, road construction,

disturbed cleared lands (i.e., vacant

lots), unpaved roads, and paved roads.

62 FR 31031. As can be seen from Table

9, the emission reductions from the

proposed FIP rule for unpaved roads

and vacant lots are sufficient to assure

incremental emission reductions

between 1998 and 2001 at the West

Chandler monitoring sites; therefore,

EPA proposes to determine that the FIP

assures RFP for the 24-hour standard at

the West Chandler monitor.

TABLE 9.—RFP DEMONSTRATION FOR THE 24-HOUR STANDARD—WEST CHANDLER MONITORING SITE

Source category

1998 Emissions (kg/

day)

FIP control

(percent)

2001 Emissions (kg/

day)

Agriculture .............................................................................................................................................. 19378 0 19378

Vacant lots .............................................................................................................................................. 6188 0.56 2723

Road Construction .................................................................................................................................. 440 0 440

Agricultural apron ................................................................................................................................... 1954 0 1954

Unpaved road ......................................................................................................................................... 49 0.64 18

Paved roads ........................................................................................................................................... 37 0 37

Total ............................................................................................................................................. 28046 ...................... 24550

VI. Impact on Indian Reservations

The Phoenix PM–10 nonattainment

area includes two Indian reservations

(the Salt River Pima-Maricopa Indian

Community and the Fort McDowell

Mojave-Apache Indian Community) and

a portion of a third (the Gila River

Indian Community). As discussed in

section II.A.4. above, EPA’s obligation is

to apply the measures in the proposed

FIP to those sources that would have

been regulated under the moderate area

PM–10 SIP. That does not include those

sources located within Indian country

that are not subject to State jurisdiction,

and the State of Arizona has not

demonstrated to EPA it has any such

jurisdiction with respect to these lands.

In addition, EPA believes it would be

inappropriate to apply federal control

measures to Indian country sources

without data showing that these sources

are contributing to the area’s

nonattainment problem. No such data

has been submitted to EPA. Therefore,

EPA proposes to exclude sources

located in Indian country from the

proposed FIP requirements.

However, EPA believes that the

solution to the Phoenix PM–10 problem

must be developed in an equitable

manner, and recognizes that such a

solution may require that emission

controls be applied to certain onreservation PM–10 sources. In order to

assess whether controls should be

applied in Indian country, it will be

necessary to obtain enough data to

identify on-reservation sources and

assess their contribution to the air

quality problem. EPA is committed to

working closely with the Indian tribes to

identify impacts of activities on the

reservations on the nonattainment area,

and to ensure, if necessary, that onreservation emissions are controlled in
15942 Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules

39The County typically only ensures compliance

with Rule 310 for these sources on a complaint

basis.

a manner consistent with attainment of

the NAAQS.

The three Phoenix-area tribal

governments have indicated their

willingness to take appropriate steps to

protect and improve air quality in the

Phoenix area. All three tribes have been

building environmental regulatory

programs for several years, and all three

have expressed their intention to add an

air quality component to these

programs. The Gila River Indian

Community and the Salt River PimaMaricopa Indian Community are

actively developing CAA programs with

grant support from EPA Region IX. The

Fort McDowell Indian Community is

working with EPA Region IX to develop

an air grant project that will result in the

development of an air quality needs

assessment for the Tribe. For all three

tribes, an early step in the program

development process will be to generate

detailed emissions inventory data and

assess the need for regulations to control

emissions from on-reservation sources.

It took many years for states to

develop the comprehensive air quality

programs that exist now; likewise, air

quality program development can be

expected to take many years for tribes.

EPA is committed to working closely

with the three Phoenix-area tribes over

the next several years to enhance and

support their air program development.

EPA will provide the necessary

technical and financial support to

ensure not only that an adequate level

of data is generated in order to assess

appropriate air pollution controls for the

reservations, but also to ensure that the

tribes develop the capacity, if they so

desire, to implement such controls

through tribal CAA programs. As a

backstop, and consistent with 40 CFR

section 49.11(a), EPA is prepared to

develop federal measures to implement

PM–10 controls necessary to attain the

NAAQS in the absence of an approved

tribal CAA program.

Furthermore, EPA recognizes that

there is a potential equity issue

regarding nonattainment area

agricultural activities as addressed by

this proposal, specifically that many of

the farms on the Indian reservations are

leased to commercial farmers who are

also actively farming off-reservation. In

order to address this issue, EPA will

actively support tribal participation in

the process of developing the

agricultural BMPs described in section

V.A.7.a. above, and will promote the

equitable implementation of BMPs

throughout the Phoenix nonattainment

area.

VII. Administrative Requirements

A. Executive Order (E.O.) 12866

Under Executive Order 12866, 58 FR

51735 (October 4, 1993), the Agency

must determine whether the regulatory

action is ‘‘significant’’ and therefore

subject to Office of Management and

Budget (OMB) review and the

requirements of the Executive Order.

The Order defines ‘‘significant

regulatory action’’ as one that is likely

to result in a rule that may:

(1) 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;

(2) Create a serious inconsistency or

otherwise interfere with an action taken or

planned by another agency;

(3) Materially alter the budgetary impact of

entitlements, grants, user fees, or loan

programs or the rights and obligations of

recipients thereof; or

(4) Raise novel legal or policy issues

arising out of legal mandates, the President’s

priorities, or the principles set forth in the

Executive Order.

Due to potential novel policy issues

this action is considered a significant

regulatory action and therefore must be

reviewed by OMB. Changes made in

response to OMB suggestions or

recommendations will be documented

in the public record.

B. Regulatory Flexibility Analysis

1. Regulatory Flexibility Act

Requirements

Under the Regulatory Flexibility Act

(RFA), 5 U.S.C. section 601 et. seq., EPA

must prepare a regulatory flexibility

analysis assessing the impact of any

proposed or final rule on small entities

unless EPA certifies that the rule will

not have a significant economic impact

on a substantial number of small

entities. 5 U.S.C. sections 603, 604 and

605(b). Small entities include small

businesses, small not-for-profit

enterprises, and government entities

with jurisdiction over populations of

less than 50,000.

For the purposes of this inquiry, as it

applies to the two proposed federal

measures, the fugitive dust rule and the

commitment for the development and

implementation of RACM for the

agricultural sector, EPA is assuming that

the affected or potentially affected

sources constitute ‘‘small entities’’ as

defined by the RFA.

The proposed federal measures are

intended to fill gaps in the Arizona PM–

10 SIP for the Phoenix nonattainment

area. For non-agricultural fugitive dust

sources, while the County has adopted

and EPA has approved Rule 310 into the

SIP, the County has not made a

commitment to provide adequate

resources to ensure enforcement of the

rule as it applies to the unpaved road,

unpaved parking lot and vacant lot

source categories.39 Further, application

of Rule 310 to agricultural sources

including fields and aprons is affected

by the provision in section 102

(incorporating A.R.S. 49–504.4) that

states that the rule ‘‘shall not be

construed so as to prevent normal farm

cultural practices.’’ Therefore,

applicability of the rule to such sources

depends on what dust-generating

operation is occurring at the source. In

other words, Rule 310 applies to some

operations on agricultural fields and

aprons and not to others.

2. RFA Analysis

a. Proposed Federal Rule for Unpaved

Roads, Unpaved Parking Lots, and

Vacant Lots. The starting point for

EPA’s analysis is Maricopa County’s

Rule 310. Regardless of the County’s

resources for enforcing the rule with

respect to nonagricultural fugitive dust

sources, those sources are legally

responsible for complying with it.

Failure to do so subjects such sources to

potential enforcement action by EPA,

the State, County and/or citizens. Thus,

for the purpose of analyzing whether the

proposed FIP rule will have ‘‘a

significant economic impact,’’ EPA

assumes that sources subject to the rule

are complying with it. The appropriate

inquiry then is whether the terms of

EPA’s proposed rule would impose a

significant economic impact beyond

that imposed by the terms of Rule 310.

Section 101 of Rule 310 states that the

purpose of the rule is ‘‘[t]o limit the

emission of particulate matter into the

ambient air from any property,

operation or activity that may serve as

an open fugitive dust source.’’ Further,

the provisions of the rule ‘‘apply to any

activity, equipment, operation and/or

man-made or man-caused condition or

practice * * * capable of generating

fugitive dust. * * *’’ Sections 305, 306,

309 and 312 of the rule contain the

regulatory requirements applicable to

the following source categories: vehicle

use in open areas and vacant parcels,

unpaved parking areas, vacant areas,

and roadways. These requirements

differ to some extent depending on the

source category, but generally they

mandate the implementation of RACM

before certain dust-producing activities
Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules 15943

40EPA believes that it is reasonable and

appropriate for its proposed rule to be more specific

and detailed than the County rule. As a result of

the State’s failure to commit sufficient enforcement

resources for its rule, EPA is having to fulfill the

role of primary enforcer of the RACM requirement

for the sources described above. EPA Region 9 will

be responsible for fulfilling that role, and it is

located in San Francisco. Given the greater

difficulties that Region 9 will inevitably face in

enforcing the RACM requirement in Arizona, it is

reasonable for EPA to design a RACM rule that

ensures EPA enforcement of the rule will be

practicable. As described above, the County rule

provides a general basis for determining which

RACM should be applied to which source

categories. But its lack of specificity makes it more

likely that the agency enforcing the rule will

routinely be called upon to address which RACM

should be applied to which source categories. By

addressing this issue in the FIP rule itself, EPA

hopes to reduce the extent to which sources and

others may have to consult with the Agency to

determine which RACM are appropriate for a

particular source or source category.

can be undertaken. RACM is defined in

section 221 as ‘‘[a] technique, practice,

or procedure used to prevent or

minimize the generation, emission,

entrainment, suspension and/or

airbourne transport of fugitive dust.’’ As

further defined in subsection 221.1, and

as pertinent to this analysis, RACM

include, but are not limited to: curbing,

paving, applying dust suppressants,

and/or physically stabilizing with

vegetation and gravel.

While subsection 211.1 does not

specify which of the listed measures are

appropriate for what types of source

categories, the general definition of

RACM in section 221 together with the

list of RACM measures in subsection

211.1 provide a basis for selecting

measures which are appropriate for a

particular source to prevent or minimize

dust emissions, to the extent other

provisions of Rule 310 do not specify a

particular RACM measure.

EPA’s proposed fugitive dust rule is

intended to establish a RACM

requirement for unpaved parking lots,

unpaved roads and vacant lots that is

substantively equivalent to that

established for the same sources by the

Maricopa County rule. As noted above,

the requirements of the County rule

differ to some extent depending on the

source category; EPA’s proposed rule

mirrors those differences. The primary

difference between the County rule and

EPA’s proposed rule is that the EPA rule

provides greater specificity and detail

regarding which RACM are appropriate

for a particular source category for the

purpose of preventing or minimizing

fugitive dust emissions.40

In providing further specificity and

detail, EPA’s proposed rule does not

change the nature of the RACM

requirement already applicable to

sources covered by County Rule 310.

The RACM required to be applied in the

proposed FIP rule are the very measures

listed in subsection 211.1 of Rule 310.

Beyond that, the RACM specified in the

proposed rule for any particular source

category are the appropriate RACM for

that source category. What constitutes

RACM for the source categories covered

by the proposed FIP rule is relatively

straightforward in light of the

differences among the source categories,

the low technology nature of the

potential RACM and other available

information. EPA therefore believes that

its further specification of the RACM

requirements does not change the nature

of the RACM requirements already

applicable under County Rule 310.

The only other notable difference

between the County rule and the

proposed FIP rule that is relevant to this

analysis is section 600 of the proposed

FIP rule. Rule 310 contains a

recordkeeping requirement for

permitted dust-generating activities, but

does not contain such a requirement for

unpermitted activities, including

unpaved parking lots, unpaved roads

and vacant lots. Therefore, section 600

of the proposed FIP rule includes a

requirement that owners/operators

subject to the rule maintain records

demonstrating appropriate application

of RACM. EPA has determined that the

recordkeeping requirements for the

source categories covered in the FIP rule

will not have a significant economic

impact. In many cases, the owner/

operator need only retain a purchase

receipt or contractor work order for the

control(s) implemented. When chemical

stabilization is applied as a control

measure, more specific information

regarding the product being used is

required. However, this information

(e.g., type of product, label instructions)

is readily available from vendors or

easily determined at the time of

application. EPA expects that the

information the proposed rule would

require sources to keep would be

retained by source owners or operators

in any event in the normal course of

business (e.g., for tax and accounting

purposes).

As the above discussion of the RACM

requirements of the two rules makes

clear, even though the proposed FIP rule

differs from Rule 310 in that it is more

specific and detailed, there should be no

additional burden on regulated sources

because they are already legally

required to apply RACM under the

County rule, and the RACM required by

the proposed FIP rule is substantively

identical to that required under Rule

310. Moreover, EPA believes that the

additional recordkeeping requirement in

the proposed FIP rule will not have a

significant economic impact on the

affected sources. As stated above and in

section V.A.7.b., the information

proposed to be retained is minimal and

is therefore not expected to entail any

appreciable economic impact.

b. Proposed Federal Commitment for

Agriculture. EPA’s proposed measure to

control fugitive dust from agricultural

fields and aprons consists of an

enforceable commitment to propose and

finalize adoption of RACM for those

sources in September 1999 and April

2000, respectively. Prior to this formal

rulemaking, EPA intends to convene a

stakeholder process to develop the

specific RACM that will ultimately be

proposed for adoption. As discussed in

detail in section V.A.7.a. above, EPA’s

intends the RACM to take the form of

BMPs. During the BMP development

process, EPA will investigate a myriad

of factors, including the appropriate

coverage of potential BMPs, regional

climate, soil and crop types, and

growing seasons.

Because this aspect of today’s action

neither proposes specific regulatory

requirements, nor obligates EPA to

propose requirements necessarily

applicable to small entities, it will not,

by itself, have a significant economic

impact on a substantial number of small

entities. When EPA proposes specific

RACM in the September 1999

rulemaking, it will either undertake a

RFA analysis or certify the proposed

rule, as appropriate.

c. Certification. For the reasons set

forth above, pursuant to 5 U.S.C. 605(b),

EPA certifies that today’s proposed

federal rules do not have a significant

impact on a substantial number of small

entities within the meaning of those

terms for RFA purposes.

C. Unfunded Mandates Reform Act

(UMRA)

Title II of the Unfunded Mandates

Reform Act of 1995 (UMRA), P.L. 104–

4, establishes requirements for Federal

agencies to assess the effects of their

regulatory actions on State, local, and

tribal governments and the private

sector.

Under section 202 of the UMRA, EPA

generally must prepare a written

statement, including a cost-benefit

analysis, when EPA promulgates ‘‘any

general notice of proposed rulemaking

that is likely to result in promulgation

of any rule that includes any Federal

mandate that may result in the

expenditures by State, local, and tribal

governments, in the aggregate, or by the

private sector, of $100 million or more’’

in any one year. A ‘‘Federal mandate’’

is defined, under section 101 of UMRA,

as a provision that ‘‘would impose an

enforceable duty’’ upon the private
15944 Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules

sector or State, local, or tribal

governments’’, with certain exceptions

not here relevant.

Under section 203 of UMRA, EPA

must develop a small government

agency plan before EPA ‘‘establish[es]

any regulatory requirements that might

significantly or uniquely affect small

governments’’.

Under section 204 of UMRA, EPA is

required to develop a process to

facilitate input by elected officers of

State, local, and tribal governments for

EPA’s ‘‘regulatory proposals’’ that

contain significant Federal

intergovernmental mandates.

Under section 205 of UMRA, before

EPA promulgates ‘‘any rule for which a

written statement is required under

[UMRA section] 202’’, EPA must

identify and consider a reasonable

number of regulatory alternatives and

either adopt the least costly, most costeffective or least burdensome alternative

that achieves the objectives of the rule,

or explain why a different alternative

was selected.

As explained above, while the

proposed federal fugitive dust rule may

impose an enforceable duty on State or

local governments, the resulting

expenditures by those entities are

expected to be minimal. Tribal

governments are excluded from the

coverage of this proposed rule. In

addition, there will be no current

enforceable duties imposed on, or

expenditures by, State, local or tribal

governments or the private sector as a

result of the proposed federal

commitment regarding the agricultural

sector. Therefore, expenditures by State,

local and tribal governments, in the

aggregate, or by the private sector, will

be well under $100 million per year as

a result of today’s proposed federal

measures. Consequently, sections 202,

204 and 205 of UMRA do not apply to

today’s proposed action. Therefore, EPA

is not required and has not taken any

actions to meet the requirements of

these sections of UMRA.

With respect to section 203 of UMRA,

EPA has concluded that its proposed

actions include no regulatory

requirements that will significantly or

uniquely affect small governments. As

discussed in detail in section VII.B.

above, EPA believes that the RACM

requirements of the proposed FIP rule

for vacant lots, unpaved parking lots

and unpaved roads are already legally

required under Maricopa County Rule

310. Moreover, the requirements of

EPA’s proposed FIP rule, while more

specific and detailed, are substantively

identical to those required under Rule

310. Therefore, there should be no

additional burden on regulated sources,

including small governments. With

respect to EPA’s proposed enforceable

commitment for the agricultural sector,

such a commitment neither proposes

specific regulatory requirements, nor

obligates EPA to propose requirements

necessarily applicable to small entities.

Thus, neither EPA’s proposed fugitive

dust rule nor its proposed commitment

for the agricultural sector will

significantly or uniquely affect small

governments. Consequently, EPA has

not developed a small government plan.

Nevertheless, during the development of

today’s proposed action, EPA held

numerous meetings with potentially

affected representatives of the State and

local governments to discuss the

requirements of, and receive input

regarding, the proposed federal fugitive

dust rule and commitment for the

agricultural sector.

D. Paperwork Reduction Act

The information collection

requirements in this proposed rule have

been submitted for approval to the

Office of Management and Budget

(OMB) under the Paperwork Reduction

Act, 44 U.S.C. 3501 et seq. An

Information Collection Request (ICR)

document has been prepared by EPA

(ICR No. 1855.01) and a copy may be

obtained from Sandy Farmer, OPPE

Regulatory Information Division; U.S.

Environmental Protection Agency

(2137); 401 M St., S.W.; Washington, DC

20460 or by calling (202) 260–2740.

EPA’s proposed FIP rule for unpaved

parking lots, unpaved roads and vacant

lots includes recordkeeping and

reporting requirements which will help

ensure source compliance with the

rule’s control requirements. In general,

EPA believes the recordkeeping and

reporting requirements are the minimal

requirements necessary to demonstrate

compliance. The requirents include:

—Owners/operators of unpaved roads must

keep a record which indicates the date and

type of control (i.e., paving, stabilizing, or

applying gravel) applied to the road.

—Owners/operators of unpaved parking lots

must keep a record which indicates the

date and type of control (i.e., paving,

stabilizing, applying gravel, or temporary

stabilization for lots used less than 35 days

per year) applied to the unpaved parking

lot.

—Responsible party(ies) for unpermitted

weed abatement activities on vacant lots

must develop a dust control plan and

submit the plan to EPA for approval prior

to the weed abatement.

—Owners/operators of vacant lots with

disturbed surfaces must keep a record

which indicates the date and type of

control (i.e., applying ground cover

vegetation, stabilizing, restoring to natural

undisturbed state, or applying gravel)

applied to the vacant lot.

—Owners/operators of vacant lots with motor

vehicle disturbances must keep a record

which indicates the date and type of

control (i.e., installing signs, fences, dust

suppressants, or cement barriers) applied

to the vacant lot.

—Agency surveys will be conducted by the

EPA or other appropriate agency to

determine the effectiveness of the rule in

the Phoenix area.

The estimated recordkeeping and

reporting burden for the proposed FIP

rule is about 9716 hours. The estimated

labor cost is about $173,632. No capital/

start-up costs or operational and

maintenance costs are anticipated.

Burden means the total time, effort, or

financial resources expended by persons

to generate, maintain, retain, or disclose

or provide information to or for a

Federal agency. This includes the time

needed to review instructions; develop,

acquire, install, and utilize technology

and systems for the purposes of

collecting, validating, and verifying

information, processing and

maintaining information, and disclosing

and providing information; adjust the

existing ways to comply with any

previously applicable instructions and

requirements; train personnel to be able

to respond to a collection of

information; search data sources;

complete and review the collection of

information; and transmit or otherwise

disclose the information.

An agency may not conduct or

sponsor, and a person is not required to

respond to a collection of information

unless it displays a currently valid OMB

control number. The OMB control

number for EPA’s regulations are listed

in 40 CFR Part 9 and 48 CFR Chapter

15.

Comments are requested on the

Agency’s need for this information, the

accuracy of the provided burden

estimates, and any suggested methods

for minimizing respondent burden,

including through the use of automated

collection techniques. Send comments

on the ICR to the Director, OPPE

Regulatory Information Division; U.S.

Environmental Protection Agency

(2137); 401 M St., S.W.; Washington, DC

20460; and to the Office of Information

and Regulatory Affairs, Office of

Management and Budget, 725 17th St.,

N.W. Washington, DC 20503, marked

‘‘Attention: Desk Officer for EPA.’’

Include the ICR number in any

correspondence. Since OMB is required

to make a decision concerning the ICR

between 30 and 60 days after April 1,

1998, a comment to OMB is best assured

of having its full effect if OMB receives

it by May 1, 1998. The final rule will

respond to any OMB or public
Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules 15945

comments on the information collection

requirements contained in this proposal.

List of Subjects in 40 CFR Part 52

Environmental protection, Air

pollution control, Intergovernmental

relations, Particulate matter, Reporting

and recordkeeping requirements.

Dated: March 20, 1998.

Carol M. Browner,

Administrator.

For the reasons set forth in the

preamble, part 52, chapter I, title 40 of

the Code of Federal Regulations is

proposed to be amended as follows:

PART 52—APPROVAL AND

PROMULGATION OF

IMPLEMENTATION PLANS

1. The authority citation for part 52

continues to read as follows:

Authority: 42 U.S.C. 7401 et seq.

Subpart D—Arizona

2. Subpart D is proposed to be

amended by adding §§ 52.127 and

52.128 to read as follows:

§ 52.127 Commitment to promulgate and

implement reasonably available control

measures for the agricultural fields and

aprons.

The Administrator shall promulgate

and implement reasonably available

control measures (RACM) pursuant to

section 189(a)(1)(C) of the Clean Air Act

for agricultural fields and aprons in the

Maricopa County (Phoenix) PM–10

nonattainment area according to the

following schedule: by no later than

September, 1999, the Administrator

shall sign a Notice of Proposed

Rulemaking; by no later than April,

2000, the Administrator shall sign a

Notice of Final Rulemaking; and by no

later than June, 2000, EPA shall begin

implementing the final RACM.

§ 52.128 Rule for unpaved parking lots,

unpaved roads and vacant lots.

(a) General.—(1) Purpose. The

purpose of this section is to limit the

emissions of particulate matter into the

ambient air from human activity on

unpaved parking lots, unpaved roads

and vacant lots.

(2) Applicability. The provisions of

this section shall apply to owners/

operators of unpaved roads, unpaved

parking lots and vacant lots and

responsible parties for weed abatement

on vacant lots in the Phoenix PM–10

nonattainment area. This section does

not apply to unpaved roads, unpaved

parking lots, or vacant lots located on an

industrial facility, construction, or

earth-moving site that has an approved

permit issued by Maricopa County

Environmental Services Division under

Rule 200, Section 305 containing a Dust

Control Plan (DCP) approved under

Rule 310 covering all unpaved parking

lots, unpaved roads and vacant lots.

Nothing in this definition shall preclude

applicability of this section to vacant

lots with disturbed surface areas due to

construction, earth-moving, weed

abatement or other dust generating

operations which have been terminated

for over eight months.

(b) Definitions.—(1) Average Daily

Trips (ADT). The average number of

vehicles that cross a given surface

during a specified 24-hour time period

as determined by the Institute of

Transportation Engineers Trip

Generation Report (6th edition, 1997) or

tube counts.

(2) Chemical Stabilizer. Any non-toxic

chemical dust suppressant which meets

any specifications, criteria, or tests

required by any federal, state, or local

water agency and is not prohibited for

use by the U.S. Environmental

Protection Agency or any applicable

law, rule or regulation.

(3) Disturbed Surface Area. Any

portion of the earth’s surface, or

materials placed thereon, which has

been physically moved, uncovered,

destabilized, or otherwise modified

from its undisturbed natural condition,

thereby increasing the potential for

emission of fugitive dust.

(4) Dust Suppressants. Water,

hygroscopic materials, solution of water

and chemical surfactant, foam, or nontoxic chemical stabilizers not prohibited

for use by the U.S. Environmental

Protection Agency or any applicable

law, rule or regulation, as a treatment

material to reduce fugitive dust

emissions.

(5) EPA. United States Environmental

Protection Agency, Region IX, 75

Hawthorne Street, San Francisco,

California 94105.

(6) Fugitive Dust. The particulate

matter entrained in the ambient air

which is caused from man-made and

natural activities such as, but not

limited to, movement of soil, vehicles,

equipment, blasting, and wind. This

excludes particulate matter emitted

directly from the exhaust of motor

vehicles and other internal combustion

engines, from portable brazing,

soldering, or welding equipment, and

from piledrivers.

(7) Lot. A parcel of land identified on

a final or parcel map recorded in the

office of the Maricopa County recorder

with a separate and distinct number or

letter.

(8) Motor Vehicle. A self-propelled

vehicle for use on the public roads and

highways of the State of Arizona and

required to be registered under the

Arizona State Uniform Motor Vehicle

Act, including any non-motorized

attachments, such as, but not limited to,

trailers or other conveyances which are

connected to or propelled by the actual

motorized portion of the vehicle.

(9) Off-Road Motor Vehicle. Any

wheeled vehicle which is used off

paved roadways and includes but is not

limited to the following: any motor

cycle or motor-driven cycle; any motor

vehicle commonly referred to as a sand

buggy, dune buggy, or all terrain

vehicle.

(10) Owner/Operator. Any person

who owns, leases, operates, controls or

supervises a fugitive dust source subject

to the requirements of this section.

(11) Paving. Applying asphalt,

recycled asphalt, concrete, or asphaltic

concrete to a roadway surface.

(12) Phoenix PM–10 Nonattainment

Area. Such area as defined in 40 CFR

81.303.

(13) PM–10. Particulate matter with an

aerodynamic diameter less than or equal

to a nominal 10 micrometers as

measured by reference or equivalent

methods that meet the requirements

specified for PM–10 in 40 CFR part 50,

appendix J.

(14) Reasonably Available Control

Measures (RACM). Techniques used to

prevent the emission and/or airborne

transport of fugitive dust and dirt.

(15) Stabilized Surface. (i) Any

unpaved road or unpaved parking lot

surface in which any fugitive dust

plume emanating from vehicular

movement does not exceed 20 percent

opacity as determined by test methods

in paragraph (g)(1) of this section.

(ii) Any vacant lot surface that has a

visible crust as determined by the test

method in paragraph (g)(2)(i) of this

section;

(iii) Any vacant lot surface that is

sufficiently vegetated as determined by

test methods in paragraph (g)(2)(ii) or

(g)(2)(iv) of this section.

(iv) Any vacant lot surface which is

stabilized as determined by the test

method in paragraph (g)(2)(iii) of this

section;

(16) Unpaved Parking Lot. A privately

or publicly owned or operated area

utilized for parking vehicles that is not

covered by concrete, asphaltic concrete,

asphalt, or recycled asphalt.

(17) Unpaved Road. Any road,

equipment path, or driveway that is not

covered by asphalt, asphaltic concrete,

recycled asphalt, or concrete. Public

unpaved roads are those open to public

access that are owned by any federal,

state, county, municipal or other
15946 Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules

governmental or quasi-governmental

agencies.

(18) Urban or Suburban Open Area.

An unsubdivided or undeveloped tract

of land adjoining a residential,

industrial, or commercial area, located

on public or private property.

(19) Vacant Lot. A subdivided

residential, industrial, institutional,

governmental, or commercial lot which

contains no approved or permitted

buildings or structures of a temporary or

permanent nature.

(c) Exemptions. The requirements in

paragraph (d) of this section do not

apply to the following:

(1) Any unpaved parking lot 5,000

square feet or less.

(2) Any vacant lot with less than 0.10

acres (4,356 square feet) of disturbed

surface area(s).

(3) Non-routine or emergency

maintenance of flood control channels

and water retention basins.

(4) Vehicle test and development

facilities and operations when dust is

required to test and validate design

integrity, product quality and/or

commercial acceptance. Such facilities

and operations shall be exempted from

the provisions of this section only if

such testing is not feasible within

enclosed facilities.

(5) Weed abatement operations

performed on any vacant lot or property

under the order of a governing agency

for the control of a potential fire hazard

or otherwise unhealthy condition

provided that mowing, cutting, or other

similar process is used to maintain

weed stubble at least three (3) inches

above the soil surface. This includes the

application of herbicides provided that

the clean-up of any debris does not

disturb the soil surface.

(6) Weed abatement operations that

receive an approved Earth Moving

permit under Maricopa County Rule

200, Section 305 (adopted 11/15/93).

(d) Requirements.—(1) Unpaved

parking lots. Any owners/operators of

an unpaved parking lot shall implement

one of the following RACM on the entire

surface area of the lot within eight (8)

months following [the effective date of

the final rule].

(i) An owner or operator of an

unpaved parking lot shall:

(A) Pave the lot; or

(B) Apply chemical stabilizers in

sufficient concentration and frequency

to maintain a stabilized surface; or

(C) Apply and maintain surface gravel

uniformly to a depth of at least 2 inches

such that the surface is stabilized.

(ii) Any owners/operators of an

unpaved parking lot that is used no

more than 35 days per year may

substitute the following control measure

for those listed in paragraph (d)(1)(i) of

this section:

(A) Apply chemical stabilizers within

20 days prior to any day in which over

100 vehicles are parked. Chemical

stabilizers must be applied in sufficient

concentration and frequency to

maintain a stabilized surface throughout

any day(s) when over 100 vehicles

ingress into the lot.

(2) Unpaved roads. Any owners/

operators of existing public unpaved

roads with ADT volumes of 150 vehicles

or greater, where at least 70% of the

road is located within the Phoenix PM–

10 nonattainment area, shall implement

one of the following RACM along the

entire surface of the road by June 10,

2000:

(i) Pave the road; or

(ii) Apply chemical stabilizers in

sufficient concentration and frequency

to maintain a stabilized surface; or

(iii) Apply and maintain surface

gravel uniformly to a depth of at least

2 inches such that the surface is

stabilized.

(3) Vacant lots. The following

provisions shall be implemented as

applicable:

(i) Weed abatement. No person shall

remove vegetation from any vacant lot

by blading, disking, plowing under or

any other means that disturbs 0.10 acres

or more of soil surface without first

obtaining EPA approval of a DCP

pursuant to paragraph (d)(3)(i)(A) of this

section to effectively prevent or

minimize fugitive dust.

(A) A DCP, containing the information

described in paragraph (e)(3) of this

section, shall be submitted to EPA at

least 60 calendar days before the weed

abatement occurs. Within 30 calendar

days of its receipt, EPA shall provide

written notice to the responsible

party(ies) approving or disapproving the

DCP. Should a DCP be disapproved,

within 14 calendar days following

receipt of any revisions provided by the

responsible party(ies) to EPA, EPA shall

provide notice to the responsible

party(ies) approving or disapproving the

DCP. Should EPA not provide written

notice of approval or disapproval within

the above deadlines, the responsible

party(ies) may assume that the DCP is

approved.

(B) Any person responsible for more

than one weed abatement operation at

non-contiguous sites may submit one

DCP covering multiple sites provided

that the contents of the DCP apply

similarly to all such sites and any

information specific to the site that is

required by paragraph (e)(3) of this

section is included.

(ii) Disturbed surfaces. Any owners/

operators of an urban or suburban open

area vacant lot which remains

unoccupied, unused, vacant or

undeveloped for more than fifteen (15)

days of which any portion has a

disturbed surface area(s) shall

implement one of the following RACM

within eight (8) months following [the

effective date of the final rule] or within

eight (8) months following the initial

fifteen-day period of inactivity,

whichever is later:

(A) Establish ground cover vegetation

on all disturbed surface areas in

sufficient quantity to maintain a

stabilized surface; or

(B) Apply dust suppressants to all

disturbed surface areas in sufficient

quantity and frequency to maintain a

stabilized surface; or

(C) Restore to a natural state, i.e. as

existing in or produced by nature

without cultivation or artificial

influence, such that all disturbed

surface areas are stabilized; or

(D) Apply and maintain surface gravel

uniformly over all disturbed surface

areas to a depth of at least 2 inches such

that all disturbed surface areas are

stabilized.

(iii) Motor Vehicle Disturbances. Any

owners/operators of an urban or

suburban open area vacant lot of which

any portion has a disturbed surface area

due to motor vehicle or off-road motor

vehicle use or parking, notwithstanding

use or parking by the owner(s), one of

the following RACM shall be

implemented within 60 calendar days

following the initial determination of

disturbance:

(A) Place signs at intervals of at least

300 feet, as measured along the access

perimeter, that state ‘‘Dust Control Area:

No Trespassing’’ with lettering at least

two inches in height; or

(B) Place fencing along the access

perimeter; or

(C) Plant shrubs or trees at least two

(2) feet in height that prohibit motor

vehicle and off-road motor vehicle entry

along the access perimeter; or

(D) Place cement barriers that prohibit

motor vehicle and off-road motor

vehicle entry along the access perimeter.

(4) Alternative control measures. For

sources subject to requirements in

paragraphs (d)(1), (d)(2), (d)(3)(ii) and

(d)(3)(iii) of this section: As an

alternative to compliance, owners/

operators may use any other alternative

control measures approved by EPA

pursuant to paragraphs (e)(1) and (e)(2)

of this section as equivalent to the

methods specified in paragraph (d) of

this section.

(e) Administrative requirements. (1)

Proposed alternative control measures

for sources subject to paragraph (d)(1) of

this section must be submitted to EPA
Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules 15947

1These proposed methods in 40 CFR part 51,

appendix M, were published at 58 FR 61640,

November 22, 1993.

for approval within one year of the

effective date of the final rule. Proposed

alternative control measures for sources

subject to paragraphs (d)(2) and (d)(3)(ii)

of this section must be submitted to EPA

for approval within 90 days prior to the

required RACM implementation date as

specified in this section. Proposed

alternative control measures for sources

subject to paragraph (d)(3)(iii) of this

section must be submitted to EPA for

approval within 60 calendar days

following the initial determination of

disturbance.

(2) Upon receipt of an alternative

control measure, EPA shall provide

written notice within 30 calendar days

to the owner/operator approving or

disapproving the alternative control

measure. Should EPA not provide

written notice of approval or

disapproval within the above deadline,

the owner/operator shall assume that

the alternative control measure is

approved. Upon receiving notice of EPA

approval, the owner/operator shall

implement the alternative control

measure according to the timeframe

established in this section unless

otherwise specified by EPA. Upon

receiving notice of EPA disapproval of

the alternative control measure, the

owner/operator shall implement RACM

according to the specifications and

timeframe established in this section.

For sources submitting an alternative

control measure under paragraph

(d)(3)(iii) of this section, owners/

operators shall implement the

alternative control measure if approved

by EPA within 60 days upon receiving

written notice, or, upon disapproval of

the alternative control measure,

implement RACM as specified in this

section within 60 days upon receiving

written notice.

(3) Information to be included in a

DCP:

(i) Name(s), address(es) and phone

number(s) of person(s) responsible for

the preparation, submittal and

implementation of the DCP and

responsible for the weed abatement

operation(s).

(ii) A plot plan of the site which

describes:

(A) The location of the site;

(B) The total area of land surface

subject to disturbance and the total area

of the entire project site, in acres;

(C) The type of weed abatement

operation(s) and equipment to be used

on the site.

(iii) A description of:

(A) Dust control measures or

combinations thereof to be applied

during all periods of weed abatement

operations, including post-weed

abatement and any operations

conducted afterwork hours and on

weekends and holidays, to all surface

areas subject to disturbance as described

in the plot plan.

(B) Dust control measures to be

applied on all days when wind speeds

exceed 25 miles per hour.

(C) Dust suppressant(s) to be applied,

including product specifications or label

instructions for approved usage; the

method, frequency and concentration of

application; the type, number and

capacity of application equipment and;

information on environmental impacts

and approvals or certifications related to

appropriate and safe use for ground

applications.

(D) The specific surface treatment(s)

and/or control measures utilized to

control material track-out and

sedimentation onto unpaved surfaces

and access points adjoining paved

surfaces.

(f) Monitoring and records (1) Any

owners/operators that are subject to the

provisions of this section shall compile

and retain records that provide evidence

of control measure application,

indicating the type of treatment or

measure, extent of coverage and date

applied. For control measures involving

chemical stabilization, records shall also

indicate the type of product applied,

vendor name, label instructions for

approved usage, and the method,

frequency and concentration of

application.

(2) Copies of control measure records

and dust control plans along with

supporting documentation shall be

retained for at least three years.

(3) Agency surveys. (i) EPA or other

appropriate entity shall conduct a

survey of the number and size (or

length) of unpaved roads, unpaved

parking lots, and vacant lots subject to

the provisions of this section located

within the Phoenix PM–10

nonattainment area beginning no later

than 365 days following [the effective

date of the final rule].

(ii) EPA or other appropriate entity

shall conduct a survey at least every

three years within the Phoenix PM–10

nonattainment area beginning no later

than 365 days following [the effective

date of the final rule] which includes:

(A) An estimate of the percentage of

unpaved roads, unpaved parking lots,

and vacant lots subject to this section to

which RACM as required in this section

have been applied; and

(B) A description of the most

frequently applied RACM and estimates

of their control effectiveness.

(g) Test methods. (1) For determining

whether unpaved roads and unpaved

parking lots are stabilized, visible

opacity from vehicular movement shall

not exceed twenty (20) percent. Opacity

observations shall be conducted in

accordance with Reference Method 9

(40 CFR part 60, appendix A), [Proposed

Methods 203A, 203B, and 203C, with

opacity readings conducted according to

Method 203C] 1. Visible opacity tests

shall only be conducted on dry unpaved

surfaces (i.e. when the surface is not

damp to the touch) and on days when

average wind speeds do not exceed 15

miles per hour (mph). For purposes of

this section, visible opacity tests shall

be conducted using the following

vehicle speeds: 35 mph on unpaved

roads and 20 mph on unpaved parking

lots.

(2) The test methods in this paragraph

(g)(2) shall be used for determining

whether a vacant lot, or portion thereof,

has a stabilized surface. Evidence of

disturbance is loss of vegetation cover

and disintegration of surface

compaction and/or crusts. The surface

shall be considered stabilized if any of

the following test methods indicate that

conditions defining a stabilized surface

have been met:

(i)(A) Where a visible crust exists

which is greater than 0.6 cm thick and

not easily crumbled between the fingers,

the surface shall be considered

stabilized. This determination shall be

based on the majority of at least three (3)

crustal measurements representative of

the disturbed surface area.

(B) If thin deposits of loose

uncombined surface material cover

more than 50 percent of a crusted

surface, the test method described in

paragraph (g)(2)(iii) of this section shall

be applied to the loose material to

determine whether the surface is

stabilized.

(ii) Where flat vegetation covers at

least 50 percent of the disturbed surface

area as determined by the line transect

method described in ‘‘Estimating

Percent Residue Cover Using the LineTransect Method’’, G93–1133 (February

1997, Electronic version), Cooperative

Extension, Institute of Agriculture and

Natural Resources, University of

Nebraska-Lincoln, the surface shall be

considered stabilized. Flat vegetation

shall include attached vegetation or

unattached vegetative debris lying on

the surface with a predominant

horizontal orientation and a vertical

height of one (1) inch or less that is not

subject to movement by wind. Flat

vegetation which is dead but firmly

attached shall be considered equally

protective as live vegetation. Stones or

other aggregate larger than one
15948 Federal Register / Vol. 63, No. 62 /Wednesday, April 1, 1998 / Proposed Rules

centimeter in diameter may be

considered protective cover in the

course of conducting the line transect

method.

(iii) For all other surface conditions,

at least three (3) soil samples shall be

collected representative of the disturbed

surface area. Each sample shall be

measured for threshold friction velocity

in accordance with the sieving field

procedure found in ‘‘Industrial Wind

Erosion’’ (Fifth Edition, Volume I,

Chapter 13, Section 13.2.5, 1995), AP–

42, Office of Air Quality Planning &

Standards, U.S. Environmental

Protection Agency, Research Triangle

Park, North Carolina. Corrections for

non-erodible elements (not including

flat or standing vegetation), shall be

determined by following the procedures

in ‘‘Rapid Assessment of Exposure to

Particulate Emissions from Surface

Contamination Sites’’, (February 1985,

Appendix A) EPA/600/8–85/002, Office

of Health and Environmental

Assessment, United States

Environmental Protection Agency,

Washington DC. Non-erodible elements

shall be defined as elements on the

disturbed surface area which remain

firmly in place during a wind episode

and inhibit soil loss by consuming part

of the shear stress of the wind, such as

stones larger than one centimeter in

diameter. Soil samples shall only be

collected from dry surfaces (i.e. when

the surface is not damp to the touch) to

a depth of approximately one (1)

centimeter. The threshold friction

velocity of all soil samples shall be

averaged. The surface shall be

considered stabilized if the threshold

friction velocity, corrected for nonerodible elements, is equal to or greater

than 100 centimeters per second.

(iv) Where standing vegetation is

firmly attached to the disturbed surface

area and the corrected threshold friction

velocity measured in paragraph

(g)(2)(iii) of this section is equal to or

greater than forty-three (43) centimeters

per second, the surface shall be

considered stabilized if the average

frontal silhouette area of the standing

vegetation per unit of ground area is ten

(10) percent or greater. Where standing

vegetation is firmly attached to the

disturbed surface area and the corrected

threshold friction velocity measured in

paragraph (g)(2)(iii) of this section is

less than forty-three (43) centimeters per

second, the surface shall be considered

stabilized if the average frontal

silhouette area of the standing

vegetation per unit of ground area is

thirty (30) percent or greater. Standing

vegetation shall include vegetation that

is attached via root systems with

predominant vertical orientation and a

height exceeding one (1) inch. Standing

vegetation which is dead but firmly

attached shall be considered equally

protective as live vegetation.

(A) For standing vegetation that

consists of separate vegetative units (for

example, shrubs and sagebrush), the

standard unit area of ground surface to

be surveyed shall be a square of side

length equal to at least 10 times the

average height of the vegetative

structure. For other standing vegetation,

the standard unit area to be surveyed

shall be three (3) feet by 3 feet.

(B) The number of standing vegetative

structures within the standard unit area

shall be counted. Vegetation which

grows in clumps shall be counted as a

single unit. Where vegetation of diverse

dimensions is present, vegetation shall

be counted separately in groups with

similar horizontal and vertical structural

dimensions. The width and height of

the vegetation that is representative of

the average dimensions of the general

vegetation within each structural group

in the standard unit area shall be

measured and multiplied together to

obtain a frontal silhouette area. The

frontal silhouette areas for each

vegetative group shall be multiplied by

the total number of vegetation counted

within each group and added together to

arrive at the total frontal silhouette area

of all standing vegetative structures. The

total frontal silhouette area shall be

divided by the total standard unit area

and multiplied by 100 to arrive at the

percent frontal silhouette area coverage.

(C) This procedure shall be repeated

for at least two additional representative

areas within the disturbed portion(s) of

the vacant lot. The three percent frontal

silhouette areas shall be averaged. Total

frontal silhouette areas of distinct

standard unit areas may only be added

together if the vegetation is relatively

uniform and consistent in spacing over

the entire disturbed surface area.

(3) Alternative test methods may be

used upon obtaining the written

approval of the EPA.

[FR Doc. 98–8061 Filed 3–31–98; 8:45 am]

BILLING CODE 6560–50–P