2954 Federal Register / Vol. 68, No. 14 / Wednesday, January 22, 2003 / Proposed Rules 

1On October 24, 2002, the Nevada Division of 

Environmental Protection submitted to EPA revised 

versions of Clark County sections 90 through 93, 

dated November 20, 2001, which supersede earlier 

versions submitted with the Plan. Also, on 

November 19, 2002, the Nevada Division of 

Environmental Protection submitted to EPA an 

amendment to the Clark County PM–10 Plan 

adopted by the Clark County Board of 

Commissioners on November 19, 2002.

2There are two separate national ambient air 

quality standards for PM–10, an annual standard of 

50 μg/m3 and a 24-hour standard of 150 μg/m3.

If the EPA receives adverse 

comments, the direct final rule will be 

withdrawn and all public comments 

received will be addressed in a 

subsequent final rule based on this 

proposed rule. The EPA will not 

institute a second comment period. Any 

parties interested in commenting on this 

action should do so at this time. Please 

note that if we receive adverse comment 

on an amendment, paragraph, or section 

of this rule and if that provision may be 

severed from the remainder of the rule, 

we may adopt as final those provisions 

of the rule that are not the subject of an 

adverse comment. 

For additional information, see the 

Direct Final rule which is located in the 

Rules section of this Federal Register.

Dated: December 17, 2002. 

L. John Iani, 

Regional Administrator, Region 10.

[FR Doc. 03–853 Filed 1–21–03; 8:45 am] 

BILLING CODE 6560–50–P

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 52 

[NV–040–0067; FRL–7440–5] 

Approval and Promulgation of 

Implementation Plans; Nevada—Las 

Vegas Valley PM–10 Nonattainment 

Area; Serious Area Plan for Attainment 

of the Annual and 24-Hour PM–10 

Standards

AGENCY: Environmental Protection 

Agency (EPA).

ACTION: Proposed rule.

SUMMARY: EPA proposes to approve 

provisions of the PM–10 State 

Implementation Plan for Clark County,

June 2001, (Clark County plan) that 

address attainment of the annual and 

24-hour PM–10 national ambient air 

quality standards. We also propose to 

grant Nevada’s request to extend the 

Clean Air Act deadline for attaining the 

24-hour PM–10 standard in the Las 

Vegas area from 2001 to 2006.

DATES: Comments on this proposal must 

be received in writing by February 21, 

2003. Comments should be addressed to 

the contact listed below.

ADDRESSES: Comments should be 

mailed to: Karen Irwin, Office of Air 

Planning (AIR–2), EPA Region 9, 75 

Hawthorne Street, San Francisco, CA 

94105–3901. 

A copy of docket No. NV–01–03, 

containing the EPA technical support 

document (TSD) and other material 

relevant to this proposed action, is 

available for public inspection at EPA’s 

Region 9 office during normal business 

hours. We may charge you a reasonable 

fee for copying parts of the docket. 

Environmental Protection Agency, 

Region 9, Air Division, Air Planning 

Office (AIR–2), 75 Hawthorne Street, 

San Francisco, CA 94105–3901. 

Copies of the SIP materials are also 

available for inspection at the addresses 

listed below: Clark County Department 

of Air Quality Management, 500 S. 

Grand Central Pky, Las Vegas, Nevada 

89155. Nevada Division of 

Environmental Protection, 333 West 

Nye Lane, Carson City, Nevada 89710. 

Electronic Availability 

This document and the TSD are also 

available as electronic files on EPA’s 

Region 9 Web Page at http://

www.epa.gov/region09/air.

FOR FURTHER INFORMATION CONTACT:

Karen Irwin, Office of Air Planning 

(AIR–2), U.S. Environmental Protection 

Agency, Region 9, 75 Hawthorne Street, 

San Francisco, California 94105. (415) 

947–4116, email: irwin.karen@epa.gov.

SUPPLEMENTARY INFORMATION:

Table of Contents 

I. Summary of Today’s Proposal 

II. Background to Today’s Proposal 

A. PM–10 Air Quality in the Las Vegas 

Area 

B. Previous Actions on Clark County PM–

10 Plans

III. The CAA’s Planning Requirements for 

Serious PM–10 Nonattainment Areas 

IV. The Clark County Plan’s Compliance with 

the CAA’s Requirements for Serious PM–

10 Nonattainment Areas 

A. Completeness of the SIP Submittals 

B. Adequacy of Transportation Conformity 

Budgets 

C. Adequate Monitoring Network 

D. Emissions Inventory 

E. Contribution to PM–10 Exceedences of 

Major Sources of PM–10 Precursors 

F. Implementation of Best Available 

Control Measures 

1. Steps 1 and 2: Determination of 

Significant Sources—Adequate Modeling 

2. Step 3: Identification of potential BACM 

3. Step 4: Implementation of BACM and 

inclusion of MSM for Each Significant 

Source Category 

a. Disturbed Vacant Land 

b. Unpaved Parking Lots 

c. Construction Sites 

d. Paved Road Dust 

e. Unpaved Roads 

f. Race Tracks 

g. Section 0 

G. Applicable SIP Rules 

H. General SIP Requirements and 

Enforcement of Fugitive Dust Rules 

I. Demonstration of Attainment and 

Attainment Date Extension 

1. Apply for an Extension 

2. Demonstrate the Impracticability of 

Attainment By December 31, 2001 

3. Complied With the Commitments and 

Requirements in the SIP 

4. Include the Most Stringent Measures 

5. Demonstrate Expeditious Attainment 

6. Other Factors That EPA May Consider 

7. Conclusion on the Extension Request 

J. Reasonable Further Progress and 

Quantitative Milestones 

K. Contingency Measures 

L. Administrative Requirements

I. Summary of Today’s Proposal 

First, we propose to approve the 

provisions in the PM–10 State 

Implementation Plan for Clark County,

submitted on July 25, 2001,1 (‘‘the Clark 

County serious area plan’’ or ‘‘Plan’’) 

that address attainment of the annual 

and 24-hour PM–10 standards.2 Our 

proposed actions are based on our 

initial determination that the Clark 

County serious area plan complies with 

the Clean Air Act’s (CAA or ‘‘the Act’’) 

requirements for serious PM–10 

nonattainment area plans.

First, we propose to approve the 

following specific elements of the plan 

as they pertain to the standards: 

• Demonstration that the plan 

provides for implementation of best 

available control measures (BACM); 

• Emissions inventory; 

• Demonstration of attainment of the 

annual standard by the CAA deadline of 

December 31, 2001 and demonstration 

that attainment of the 24-hour standard 

by December 31, 2001 is impracticable; 

• Demonstration that attainment of 

the 24-hour standard will occur by the 

most expeditious alternative date 

practicable, in this case, December 31, 

2006; 

• Clark County fugitive dust rules 

(Sections 90 through 94 and portions of 

Section 0); 

• Demonstration that the plan 

provides for reasonable further progress 

and quantitative milestones; 

• Transportation conformity budget; 

and 

• Contingency measures. 

Second, we are proposing to grant 

Nevada’s request to extend the 

attainment date for the 24-hour PM–10 

standard from December 31, 2001 to 

December 31, 2006. We make this 

proposal based on our determination 

that the State has met the CAA’s criteria 

for granting such extensions.

This preamble describes our proposed 

actions on the Clark County serious area

Federal Register / Vol. 68, No. 14 / Wednesday, January 22, 2003 / Proposed Rules 2955

3However, in a June 2002 letter, the Clark County 

Department of Air Quality Management (DAQM) 

provides an analysis of PM–10 microscale sites that 

demonstrates attainment of the annual standard as 

forecasted in the Clark County Plan as of December 

31, 2001. While EPA is proposing to approve the 

Plan’s attainment demonstration for the annual 

standard under CAA section 189, our action does 

not include an official finding of attainment of the 

annual standard per CAA section 188.

4When a moderate area is reclassified to serious, 

the requirement to implement RACM in section 

189(a)(1)(C) remains and is augmented by the 

requirement to implement BACM. Thus, a serious 

area PM–10 plan must, in addition to BACM, 

provide for the implementation of RACM as 

expeditiously as practicable to the extent that the 

RACM requirement has not been satisfied in the 

area’s moderate area plan. However, to the extent 

that a serious nonattainment area plan provides for 

BACM, we interpret the BACM requirement as 

generally subsuming the RACM requirement (i.e. if 

we determine that the measures are indeed the 

‘‘best available,’’ we have necessarily concluded 

that they are ‘‘reasonably available’’).

5 ‘‘State Implementation Plans; General Preamble 

for the Implementation of Title I of the Clean Air 

Act Amendments of 1990,’’ 57 FR 13498 (April 16, 

1992) and 57 FR 18070 (April 28, 1992).

6 ‘‘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 (August 16, 

1994)

plan and provides a summary of our 

evaluation of the plan. Our detailed 

evaluation of the Plan can be found in 

the TSD that accompanies this proposal. 

See ‘‘Technical Support Document 

Proposing Approval of the PM–10 State 

Implementation Plan for the Clark 

County Serious PM–10 Nonattainment 

Area Annual and 24-Hour PM–10 

Standards,’’ December 19, 2002. A copy 

of EPA’s TSD can be downloaded from 

our website or obtained by calling or 

writing the contact person listed above. 

II. Background to Today’s Proposals 

A. PM–10 Air Quality in the Las Vegas 

Area 

The Las Vegas Valley Nonattainment 

Area, which coincides with 

Hydrographic Basin 212, is roughly 

1,500 square miles in size and 

encompasses the City of Las Vegas, the 

City of North Las Vegas, the City of 

Henderson and the unincorporated 

areas of Clark County. The population of 

the area is approximately 1.15 million 

people and is expected to grow to 1.59 

million by 2006. 

The area violates both the annual 3

and 24-hour PM–10 standards. In 1990, 

the area was designated nonattainment 

for PM–10 and classified as moderate. In 

1993, because of continuing violations 

of both PM–10 standards, the area was 

reclassified to serious and required to 

provide for the implementation of 

BACM by February 8, 1997. 58 FR 3334 

(January 8, 1993).

The principal contributors to elevated 

PM–10 levels in the Las Vegas area are 

fugitive dust sources such as disturbed 

vacant lots, construction sites, unpaved 

roads and paved road dust. Fugitive 

dust is particulate matter suspended in 

the air either by mechanical disturbance 

of the surface material or by wind action 

blowing across surfaces. 

B. Previous Actions on Clark County 

PM–10 Plans 

Clark County prepared and submitted 

a serious area PM–10 plan in 1997 that 

EPA proposed to disapprove, along with 

previously submitted plans. 65 FR 

37324, June 14, 2000. On December 5, 

2000, prior to EPA taking final action on 

its proposed disapproval, the State of 

Nevada withdrew the moderate and 

serious area plans for Clark County. On 

January 5, 2001, EPA proceeded with a 

finding of nonsubmittal, effective as of 

December 20, 2000, which began the 18-

month time clock for mandatory 

application of sanctions and 2-year time 

clock for promulgation of a federal 

implementation plan (FIP). 66 FR 1046. 

On June 19, 2001, the Clark County 

Board of Commissioners adopted a new 

serious area PM–10 plan titled ‘‘PM–10 

State Implementation Plan for Clark 

County’’ (‘‘Plan’’), which was submitted 

to EPA on July 25, 2001. On January 31, 

2002, EPA made a completeness finding 

on the Plan. We have also determined 

that the conformity budgets in the plan 

are adequate. 67 FR 1461, January 11, 

2002. Our adequacy determination was 

effective on January 28, 2002. 

III. The CAA’s Planning Requirements 

for Serious PM–10 Nonattainment 

Areas 

The Las Vegas area is a PM–10 

nonattainment area that has been 

reclassified to serious because it failed 

to attain by the moderate area 

attainment date of December 31, 1994. 

Such an area must submit, within 18 

months of the reclassification, revisions 

to its implementation plan that address 

the CAA requirements for serious PM–

10 nonattainment areas. CAA section 

189(b)(2). These requirements are: 

(a) Assurances that the BACM, 

including best available control 

technology (BACT) for stationary 

sources, for the control of PM–10 shall 

be implemented no later than 4 years 

after the area is reclassified (CAA 

section 189(b)(1)(B)); 4

(b) Assurances that BACT on major 

stationary sources of PM–10 precursors 

shall be implemented no later than 4 

years after the area is reclassified except 

where EPA has determined that such 

sources do not contribute significantly 

to exceedences of the PM–10 standards 

(CAA section 189(e)); 

(c) A demonstration (including air 

quality modeling) that the plan will 

provide for attainment as expeditiously 

as practicable but no later than 

December 31, 2001 or where the State is 

seeking an extension of the attainment 

date under section 188(e), a 

demonstration that attainment by 

December 31, 2001 is impracticable and 

that the plan provides for attainment by 

the most expeditious alternative date 

practicable (CAA sections 188(c)(2) and 

189(b)(1)(A)); 

(d) Quantitative milestones which are 

to be achieved every 3 years and which 

demonstrate reasonable further progress 

(RFP) toward attainment by the 

applicable attainment date (CAA 

sections 172(c)(2) and 189(c)); and 

(e) A comprehensive, accurate, and 

current inventory of actual emissions 

from all sources of PM–10 (CAA section 

172(c)(3)). 

Serious area PM–10 plans must also 

include contingency measures to be 

implemented if the area fails to make 

RFP or attain by its attainment deadline. 

These contingency measures are to take 

effect without further action by the State 

or the Administrator. CAA section 

172(c)(9).

Furthermore, serious area PM–10 

plans must meet the general 

requirements applicable to all SIPs 

including 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 a 

description of enforcement methods as 

required by 40 CFR 51.111. 

We have issued a General Preamble 5

and Addendum to the General 

Preamble 6 describing our preliminary 

views on how the Agency intends to 

review SIPs submitted to meet the 

CAA’s requirements for PM–10 plans. 

The General Preamble mainly addresses 

the requirements for moderate areas and 

the Addendum, the requirements for 

serious areas.

BACM Requirement 

The CAA does not define what level 

of control constitutes a BACM-level of 

control. In guidance, we have defined it 

to be, among other things, the maximum 

degree of emission reduction achievable 

from a source or source category which 

is determined on a case-by-case basis, 

considering energy, economic and 

environmental impacts. Addendum at 

42010. This level of control is

2956 Federal Register / Vol. 68, No. 14 / Wednesday, January 22, 2003 / Proposed Rules 

7We have long held that an otherwise available 

measure is not reasonable if it cannot be 

implemented on a schedule that will advance the 

attainment date. See, e.g., 57 FR 13498, 15560 

(April 16, 1992). See also Delaney v. EPA, 898 F.2d 

695 (9th Cir. 1990) which required the adoption of 

‘‘all available control measures’’ to attain ‘‘as soon 

as possible’’ and not simply all available control 

measures. The most clear example of this is a 

measure that cannot be implemented until after the 

applicable attainment date.

8An example: A measure requires all unpaved 

roads with average daily trips (ADT) over 150 be 

stabilized by either paving, graveling, or treating 

with chemical stabilizers. The control requirement 

here is ‘‘stabilize using one of these three methods: 

paving, graveling, or chemical stabilization’’ and 

the applicability is ‘‘all unpaved roads with ADT 

over 150.’’

9Here our guidance refers to RACM, however, 

since BACM builds upon RACM, the same 

principles apply.

dependent on the deadline by which 

BACM must be implemented.7

We also considered a BACM-level 

control as going beyond existing RACMlevel controls, such as expanding use of 

RACM (e.g, paving more miles of 

unpaved roads). Addendum at 42013. 

The word ‘‘best’’ implies that there 

should be a greater emphasis on the 

merits of the measure or technology 

alone and less flexibility in considering 

other factors. Additionally, we believe 

that BACM should emphasize 

prevention rather than remediation (e.g., 

preventing track out at construction 

sites rather than simply requiring clean 

up of tracked-out dirt). Addendum at 

42013. 

The stringency of a control measure is 

a function of both the measure’s 

applicability and its control requirement 

(i.e., what sources in the category are 

subject to the measure and what does 

the measure require the sources to do to 

reduce emissions).8 Both these elements 

must be specified before the measure’s 

level of control can be determined. Thus 

in setting a BACM, a state must specify 

both the measure’s control requirement 

and its applicability. The control 

requirement alone is not sufficient.

BACM must be applied to each 

significant (i.e., non-de minimis) source 

category. Addendum at 42011. In 

guidance, we have established a 

presumption that a ‘‘significant’’ source 

category is one that contributes 5 μg/m3 

or more of PM–10 to a location of 24-

hour violation and 1 μg/m3 or more for 

the annual standard. Addendum at 

42011. However, whether the threshold 

should be lower than this in any 

particular area depends upon the 

specific facts of that area’s 

nonattainment problem. Specifically, it 

depends on whether requiring the 

application of BACM on source 

categories below a proposed de minimis 

level would meaningfully expedite 

attainment. 

We have outlined in our guidance a 

multi-step process for identifying 

BACM. Addendum at 42010–42014. The 

steps are: 

1. develop a detailed emissions 

inventory of PM–10 sources and source 

categories, 

2. model to evaluate the impact on 

PM–10 concentrations over the 

standards of the various sources and 

source categories to determine which 

are significant, 

3. identify potential BACM for 

significant source categories and 

evaluate their reasonableness, 

considering technological feasibility, 

costs, and energy and environmental 

impacts and 

4. provide for the implementation of 

the BACM or provide a reasoned 

justification for rejecting any potential 

BACM.

When the process is complete, the 

individual measures 9 should then be 

converted into a legally enforceable 

vehicle (e.g., a regulation or permit 

process). CAA sections 172(6) and 

110(a)(2)(A). Also, the regulations or 

other measures should meet EPA’s 

criteria regarding the enforceability of 

SIPs and SIP revisions. General 

Preamble at 13541.

RACM Requirement 

When a moderate area is reclassified 

to serious, the requirement to 

implement RACM in section 

189(a)(1)(C) remains. Thus, a serious 

area PM–10 plan must also provide for 

the implementation of RACM as 

expeditiously as practicable to the 

extent that the RACM requirement has 

not been satisfied in the area’s moderate 

area plan. 

However, we do not normally conduct 

a separate evaluation to determine if a 

serious area plan’s measures also meet 

the RACM requirements as interpreted 

by us in the General Preamble at 13540. 

This is because in our serious area 

guidance (Addendum at 42010), we 

interpret the BACM requirement, as 

generally subsuming the RACM 

requirement. Therefore, a separate 

analysis to determine if the measures 

represent a RACM level of control is 

generally not necessary. Our proposed 

approval of the Clark County Plan’s 

provisions relating to the 

implementation of BACM is also a 

finding that the plan provides for the 

implementation of RACM. 

The Clean Air Act Requirements for 

Attainment Date Extensions 

Section 188(e) of the Act allows us to 

extend the attainment date for a serious 

area for up to five years beyond 2001 if 

attainment by 2001 is impracticable. 

However, before we may grant an 

extension of the attainment date, the 

State must first: 

1. Apply to us for an extension of the 

PM–10 attainment date beyond 2001, 

2. Demonstrate that attainment by 

2001 is impracticable, 

3. Have complied with all 

requirements and commitments 

applying to the area in its 

implementation plan, 

4. Demonstrate to our satisfaction that 

its serious area plan includes the most 

stringent measures that are included in 

the implementation plan of any state 

and/or are achieved in practice in any 

state and are feasible for the area, and 

5. Submit a demonstration of 

attainment by the most expeditious 

alternative date practicable. 

In determining whether to grant an 

extension and the appropriate length of 

the attainment date extension, we may 

consider: 

1. The nature and extent of the 

nonattainment problem, 

2. The types and numbers of sources 

or other emitting activities in the area 

(including the influence of 

uncontrollable natural sources and 

international transport),

3. The population exposed to 

concentrations in excess of the standard, 

4. The presence and concentration of 

potentially toxic substances in the mix 

of particulate emissions in the area, and 

5. The technological and economic 

feasibility of various control measures. 

Under the Act, we may grant only one 

extension for an area and the extension 

cannot be for more than 5 years after 

2001; that is, the extended attainment 

date can be no later than December 31, 

2006. 

IV. The Clark County Plan’s 

Compliance With the CAA’s 

Requirements for Serious PM–10 

Nonattainment Areas 

The following sections present a 

condensed discussion of our evaluation 

of the Clark County Plan’s compliance 

with the applicable CAA requirements 

for attaining the annual and 24-hour 

PM–10 standards. Our complete 

evaluation is found in the TSD for this 

proposal. A copy of the TSD can be 

downloaded from our website or 

obtained by calling or writing the 

contact person listed above. 

A. Completeness of the SIP Submittal 

CAA section 110(k)(1)(B) requires us 

to determine if a SIP submittal is 

complete within 60 days of its receipt. 

This completeness review allows us to 

quickly determine if the submittal

Federal Register / Vol. 68, No. 14 / Wednesday, January 22, 2003 / Proposed Rules 2957

includes all the necessary items and 

information we need to take action on 

it. We make completeness 

determinations using criteria we have 

established in 40 CFR part 51, appendix 

V. 

On January 5, 2001, we took final 

action to find that the State of Nevada 

had failed to make PM–10 

nonattainment area SIP submittals 

required for the Las Vegas Valley 

Planning Area under the CAA. See 66 

FR 1046 (January 5, 2001). That final 

action, which was effective as of 

December 20, 2000, triggered an 18-

month clock for mandatory application 

of sanctions under section 179(a) of the 

Act and the implementing regulations 

set forth at 40 CFR 52.31. In our final 

action, we indicated that the State may 

‘‘turn off’’ the sanctions clock through 

the submission of a complete SIP 

submittal. 

Under section 110(k)(1)(B), if we do 

not make a completeness determination 

within six months of receipt of a SIP 

submittal, then the submittal shall be 

deemed complete by operation of law. 

We had not made this determination by 

January 25, 2002 (i.e., six months from 

receipt); thus, the State’s SIP submittal 

dated July 23, 2001 was deemed 

complete by operation of law effective 

January 25, 2002. 

However, a SIP submittal that is 

deemed complete by operation of law 

does not stop a sanctions clock started 

by a finding by us under section 179(a) 

of the Act. To stop the sanctions clock, 

we must make an affirmative 

determination that the deficiency 

forming the basis of the finding (in this 

case, our finding of failure to submit 

required PM–10 plan elements) has 

been corrected. See 40 CFR 52.31(d)(1). 

Therefore, we have reviewed the July 

23, 2001 PM–10 submittal from the 

State of Nevada and affirmatively 

determined that it satisfies our 

completeness criteria set forth for such 

determinations in appendix V of 40 CFR 

part 51 and that it is thereby complete 

for the purposes of section 110(k)(1) of 

the Act. Furthermore, the State’s 

submission of this complete plan 

corrects the deficiency forming the basis 

for our finding published in the Federal 

Register on January 5, 2001. We notified 

the State of our completeness 

determination by letter to NDEP on 

January 31, 2002, and our letter to NDEP 

permanently stops the sanctions clock 

as of that date. 

B. Adequacy of the Transportation 

Conformity Budgets 

CAA Section 176(c) requires that 

federally-funded or approved 

transportation plans, programs, and 

projects in nonattainment areas 

‘‘conform’’ to the area’s air quality 

implementation plans. Conformity 

ensures that federal transportation 

actions do not worsen an area’s air 

quality or interfere with its meeting the 

air quality standards. We have issued a 

conformity rule that establishes the 

criteria and procedures for determining 

whether or not transportation plans, 

programs, and projects conform to a SIP. 

See 40 CFR part 93, subpart A. 

One of the primary tests for 

conformity is to show transportation 

plans and improvement programs will 

not cause motor vehicle emissions 

higher than the levels needed to make 

progress toward and meet the air quality 

standards. The motor vehicle emissions 

levels needed to make progress toward 

and meet the air quality standards are 

set in an area’s attainment and/or RFP 

plans and are known as the ‘‘emissions 

budget for motor vehicles.’’ Emissions 

budgets are established for specific 

years and specific pollutants. See 40 

CFR 93.118(a). 

Before an emissions budget in a 

submitted SIP revision can be used in a 

conformity determination, we must first 

determine that it is adequate. The 

criteria by which we determine 

adequacy of submitted emission budgets 

are outlined in our conformity rule in 40 

CFR 93.118(e)(4). A finding of adequacy 

does not approve an emissions budget, 

it simply allows States to begin to use 

the budget in conformity determinations 

pending our action on the overall SIP. 

The Clark County Plan establishes a 

mobile source emissions budget of 

201.75 tons per day (tpd) for 2001 and 

an emissions budget of 141.41 tpd for 

2006. This regional budget is applicable 

to both the annual and 24-hour PM–10 

standards. 

On November 9, 2001, we notified the 

State that we find adequate for 

transportation conformity purposes this 

motor vehicle emissions budget. Our 

adequacy determination was effective 

on January 28, 2002 and is documented 

in section C of the TSD. As a result of 

our adequacy finding, the Regional 

Transportation Commission (RTC) and 

the Federal Highway Administration 

(FHWA) are now required to use this 

budget in all conformity analyses.

As discussed later in this preamble, 

we are proposing to approve both the 

attainment and reasonable further 

progress demonstrations for the 24-hour 

standard in the Clark County Plan. An 

emissions budget was set at 155.77 tpd 

for the 2003 interim year, which is 

consistent with these demonstrations. 

We, therefore, propose to approve the 

motor vehicle emissions budget for the 

annual and 24-hour PM–10 standards 

under CAA section 176(c). 

C. Adequate Monitoring Network 

We discuss the adequacy of the 

monitoring network in this preamble 

solely to support our finding that the 

plan appropriately evaluates the PM–10 

problem in the Las Vegas area. Reliable 

ambient data is necessary to validate the 

base year air quality modeling which in 

turn is necessary to assure sound 

attainment demonstrations. 

The CAA requires states to establish 

and operate air monitoring networks to 

compile data on ambient air quality for 

all criteria pollutants. CAA section 

110(a)(2)(B)(i). Our regulations in 40 

CFR part 58 establish specific regulatory 

requirements for operating air quality 

surveillance networks to measure 

ambient concentrations of PM–10, 

including measurement method 

requirements, network design, quality 

assurance procedures, and in the case of 

large urban areas, the minimum number 

of monitoring sites designated as 

National Air Monitoring Stations 

(NAMS). 

Ambient networks, however, do not 

need to meet all our regulations to be 

found adequate to support air quality 

modeling. A good spatial distribution of 

sites, correct siting, and quality-assured 

and quality-controlled data are the most 

important factors for air quality 

modeling. Nonattainment area plans 

developed under title I, part D of the 

Clean Air Act are not, in general, 

required to address how the area’s air 

quality network meets our monitoring 

regulations. These plans are submitted 

too infrequently to serve as the vehicle 

for assuring that monitoring networks 

remain current. 

The DAQM operates 17 monitoring 

sites collecting PM–10 data in the Las 

Vegas area, about half of which are 

designated as special purpose monitors 

(SPMs) with the remaining monitors 

designated as NAMS or state/local 

monitoring stations. Table MON–2 in 

the TSD lists the names of the sites and 

their locations in the Las Vegas area as 

of July 2000. Many of the SPM sites 

operated by the DAQM are in fact long 

term sites that have been in operation 

longer than three years. EPA performed 

a technical system audit of the DAQM’s 

ambient air monitoring program in 

August 2001. In this audit, EPA 

identified some concerns with how 

DAQM characterizes its monitoring 

networks in terms of site objectives, that 

at least two more NAMS sites are 

needed, and that the quality assurance 

program needs to be better defined and 

integrated into the daily functions of the 

air monitoring program. However, we

2958 Federal Register / Vol. 68, No. 14 / Wednesday, January 22, 2003 / Proposed Rules 

10The microscale inventories include only 

sources within a small area surrounding each 

monitor rather than all sources within the entire 

nonattainment area, the requirement in CAA 

section 172(c)(3).

do not believe these deficiencies 

adversely affect our ability to determine 

the air quality status of the area. 

The Las Vegas PM–10 network 

employs a large number of monitoring 

sites that are spread out over the Las 

Vegas valley. Given the nature of the 

emission sources, which are mostly 

local fugitive dust sources, and since 

PM–10 is a localized yet widespread 

pollutant, we believe a dense network 

such as DAQM operates is appropriate. 

The 24-hour attainment 

demonstration in the Clark County plan 

relies, in part, on showing attainment at 

five specific monitoring sites. These 

sites were chosen based on the fact that 

they represent the worst case 

environments for a mix of PM–10 

emission sources: East Flamingo site for 

its high traffic volume; Green Valley for 

its nearby highway construction and 

race tracks; J.D. Smith for its mixture of 

roadways, small point sources and 

construction sites; Craig Road for its 

light industrial facility and vacant land 

influences; and Pittman for its larger 

stationary sources, unpaved parking lots 

and unpaved roads. In 1997–1999 these 

sites cumulatively recorded 43 

exceedences of the 24-hour PM–10 

standard. They are also representative of 

similar areas in the Las Vegas area that 

may not have monitoring sites. 

In conclusion, we believe the 

monitoring network operated by the 

DAQM in 1998 was adequate to support 

the technical evaluation of the PM–10 

nonattainment problem for the Clark 

County Plan. The network utilizes EPA 

reference or equivalent method 

monitors and the DAQM performs 

routine precision and accuracy checks 

of the monitoring equipment and 

performs necessary maintenance when 

warranted. 

D. Emissions Inventory 

CAA section 172(c)(3) requires that 

nonattainment area plans include a 

comprehensive, accurate, and current 

inventory of actual emissions from all 

sources in the nonattainment area in the 

designated base year and a future 

attainment year. To meet this 

requirement, Clark County prepared a 

1998 base year annual emissions 

inventory for the entire nonattainment 

area. See Clark County Plan, Chapter 3, 

Table 3–1. Emissions inventories for the 

baseline and future years for both the 

annual and 24-hour standards are 

necessary prerequisites to meet 

requirements for BACM and 

demonstration of attainment per CAA 

section 189(b). In the Las Vegas Valley, 

both regional and microscale modeling 

inventories are needed to accurately 

reflect the sources that are contributing 

to ambient levels of the 24-hour PM–10 

standard. By design and need, the 

microscale inventory includes only 

sources within a small area around a 

monitor rather than all sources within 

the entire nonattainment area.

For the attainment demonstration, the 

Clark County Plan relies upon regional 

annual and 24-hour emissions 

inventories associated with a portion of 

the entire PM–10 nonattainment area 

titled the ‘‘BLM Disposal Area’’. See 

Clark County Plan, Chapter 3, section 

3.3 and Appendix E. All lands 

controlled by the federal government 

outside the BLM disposal area are to 

remain in their native state and the 

boundary can only be changed by an act 

of the United States Congress. 

Approximately 99 percent of the 

nonattainment area resides within the 

BLM Disposal Area and nearly all 

anthropogenic sources within the 

nonattainment area occur within the 

BLM Disposal Area, making it the 

appropriate focus for the attainment 

demonstration. We address the 

modeling used in the attainment 

demonstration later in this notice. The 

rules adopted by Clark County to 

address sources within the BLM 

Disposal Area equally apply to the 

entire PM–10 nonattainment area. 

The Plan contains two 1998 BLM 

Disposal Area emissions inventories for 

the annual standard: a valley-wide 

inventory and a microscale inventory 

for the area surrounding the J.D. Smith 

monitoring station, which was the only 

site that measured a violation of the 

annual NAAQS. For the 24-hour 

standard, the Plan contains a base year 

emissions inventory for the design day 

(December 21, 1998), which is scaled 

from the annual valley-wide inventory 

with additional wind erosion emissions 

factored in due to specific 

meteorological conditions. 

Clark County also prepared future 

year PM–10 inventories comparing an 

‘‘uncontrolled’’ scenario to a scenario 

assuming application of control 

measures adopted by Clark County as 

BACM. The Plan contains uncontrolled 

2001 and 2006 annual valley-wide 

emissions inventories and a 2006 

uncontrolled valley-wide 24-hour 

inventory. Emissions inventories were 

also developed for each of the five 

microscale sites. These microscale 

inventories are specialized modeling 

inventories and are not intended to 

satisfy the CAA section 172(c)(3) 

requirement.10

The following fugitive dust source 

categories make up 97 percent and 99 

percent of PM–10 emissions in the base 

year annual valley-wide and 24-hour 

BLM Disposal Area inventories for the 

Las Vegas Valley, respectively: vacant 

land, construction, paved roads and 

unpaved roads. The inventory includes 

only primary PM–10 as chemical mass 

balance receptor modeling showed that 

secondary and condensable particulate 

formation contribute less than 

significant amounts to ambient PM–10 

concentrations. Clark County Plan, 

Chapter 4, section 4.2.1. 

In our review of the Plan, we found 

that the emissions estimates for all of 

the source categories are based on 

emissions factors and methodologies 

recommended by EPA, or are derived 

from a specific study or data collected 

from a source category in the area (e.g., 

vacant lots). We propose to find that the 

inventory projections methodologies 

and calculations rely upon reasonable 

assumptions and provide a sufficient 

basis upon which to assess control 

measure impacts on future PM–10 air 

quality in the Las Vegas area. Clark 

County has also included commitments 

in the Plan to improve and update the 

emissions inventories in future years. 

E. Contribution of PM–10 Exceedences 

of Major Sources of PM–10 Precursors 

CAA section 189(e) requires BACT to 

be applied to major stationary sources of 

PM–10 precursors if these sources 

contribute significantly to PM–10 

exceedences in the area. Clark County 

determined that stationary sources, 

including sand and gravel operations, 

natural gas-fired utility power plants, 

asphalt concrete plants, industrial 

processes, and other sources 

cumulatively contribute less than 1 μg/

m3 of the design day concentration, 

placing them below the 5 μg/m3

significance threshold for the 24-hour 

standard. Design day micro-inventory 

concentrations from stationary source 

emissions were higher in some cases 

(3.74 μg/m3 and 3.53 μg/m3 at the 

Pittman and Craig Road monitoring 

sites, respectively), but were still below 

the threshold of presumed significance 

for this source category. Therefore, 

BACT is not required to be applied to 

stationary sources per CAA section 

189(e). 

F. Implementation of Best Available 

Control Measures 

CAA section 189(b)(1)(B) requires that 

a serious area PM–10 plan provide for 

the implementation of BACM within 

four years of reclassification to serious. 

Under our applicable guidance, BACM 

must be applied to each significant areaVerDate Dec<13>2002 14:27 Jan 21, 2003 Jkt 200001 PO 00000 Frm 00036 Fmt 4702 Sfmt 4702 E:\FR\FM\22JAP1.SGM 22JAP1
Federal Register / Vol. 68, No. 14 / Wednesday, January 22, 2003 / Proposed Rules 2959

11Because the RACM demonstration is subsumed 

in the BACM demonstration, a separate analysis to 

determine if the measures represent a RACM level 

of control is not necessary. Our proposed approval 

of the Clark County Plan’s provisions relating to the 

implementation of BACM is also a finding that the 

plan provides for the implementation of RACM.

wide source category. Addendum at 

42011. As discussed in section III of this 

preamble, we have established a fourstep process for evaluating BACM in 

serious area PM–10 plans. 

Steps 1 and 2: Determination of 

Significant Sources 

The first step in the BACM analysis is 

to develop a detailed emissions 

inventory of PM–10 sources and source 

categories that can be used in modeling 

to determine their impact on ambient air 

quality. Addendum at 42012. The 

second step is to use this inventory in 

air quality modeling to evaluate the 

impact on PM–10 concentrations over 

the standards of the various sources and 

source categories to determine which 

are significant. 

The development of the detailed 

emissions inventory is discussed in the 

preceding section and in the TSD. We 

propose to find that the baseline 

emissions inventory contains a 

sufficient level of detail to enable 

appropriate evaluation of the Plan’s 

control measures for BACM purposes. 

The determination of source 

significance is based primarily on the 

J.D. Smith annual inventory and the 24-

hour micro-inventories at the five 

representative sites, supplemented by 

reviews of the 1998 valley-wide 24-hour 

emissions inventory, the 1998 valleywide annual emissions inventory, and 

Chemical Mass Balance modeling. Clark 

County Plan, Chapter 4, pg. 4–1.

From these evaluations, the Clark 

County Plan identifies the following 

sources as significant with respect to the 

annual standard: 

1. Disturbed vacant land/unpaved 

parking lots 

2. Construction (including highway 

construction) 

3. Paved roads 

4. Unpaved roads

The same source categories are 

deemed significant for the 24-hour 

standard, with the additional category 

of:

5. Race tracks 

Clark County determined that the 

following source categories are not 

significant for both standards:

1. Stationary point sources (sand and 

gravel operations, utilities—natural 

gas, asphalt concrete manufacture, 

industrial processes, other) 

2. Some stationary area sources (small 

point sources, fuel combustion 

sources, residential wood combustion, 

open burning, farming operations) 

3. Nonroad mobile sources (airport 

support equipment, commercial 

equipment, construction and mining 

equipment, lawn and garden 

equipment, railroad equipment, 

airport emissions) 

4. Onroad mobile vehicle exhaust and 

other emissions 

5. Secondary aerosol particulate 

Emissions from the proposed de 

minimis categories are a small 

percentage (3% collectively) of the total 

1998 BLM Disposal Area annual and 24-

hour PM–10 emissions inventories. The 

minimal contribution of the proposed 

de minimis source categories to the 

inventory supports that, both 

individually and collectively, they have 

a minor impact on elevated annual and 

24-hour PM–10 levels in the Clark 

County nonattainment area. 

For the 24-hour standard, the Clark 

County Plan demonstrates that its 

selection of significant source categories 

is appropriate by showing that controls 

on the de minimis source categories 

would not result in attainment of the 24-

hour standard by 2001. See Clark 

County Plan, Chapter 7, section 7.4. 

We propose to find that the Clark 

County Plan has not excluded any 

source categories that should be 

considered significant from its list of 

significant source categories. The Plan 

presents acceptable modeling to 

evaluate the impact of various PM–10 

sources and source categories on PM–10 

levels and to derive a comprehensive 

list of significant source categories. 

Step 3: Identification of Potential BACM 

In preparing the list of candidate 

BACM, Clark County reviewed our 

guidance documents on BACM, other 

EPA documents on PM–10 control, as 

well as PM–10 plans from other serious 

PM–10 areas in the United States. Clark 

County also evaluated controls 

proposed during public comment. 

The Clark County plan appropriately 

screened the list of candidate BACM to 

eliminate measures that did not apply to 

significant source categories in the area, 

or were technologically infeasible for 

the area because they would not reduce 

PM–10 emissions. The Clark County 

Plan also provides cost-effectiveness 

estimates for each of the candidate 

BACM. 

We propose to find that the Clark 

County Plan identified and evaluated 

potential BACM for the Las Vegas area 

consistent with our guidance. As we 

will discuss below in our evaluations of 

the implementation of BACM for each 

significant source category, we do not 

believe that the Clark County plan left 

out any candidate BACM. 

Step 4: Implementation of RACM 11 and 

BACM and Inclusion of MSM for Each 

Significant Source Category

In the following sections, we review 

the results of the Clark County Plan’s 

BACM analysis and adopted measures. 

The same control measures apply to 

BACM determinations for both the 

annual and 24-hour PM–10 standards. 

We also present our evaluation of the 

Plan’s provisions for including MSM 

alongside our evaluation of BACM 

implementation for each significant 

source category. 

Clark County adopted sections 90 

through 94 and section 0 on November 

16, 2000. Sections 90 through 93 were 

subsequently revised by the DAQM on 

November 20, 2001. Clark County 

submitted these revised rules to EPA on 

October 24, 2002 for our action in place 

of the sections 90 through 93 adopted 

on November 16, 2000. These rules 

address the significant sources 

identified in the Plan, along with SIP 

commitments for unpaved roads and 

unpaved road shoulders contained in 

Chapter 4 of the Plan. 

Clark County has also committed to 

increase its staffing levels to enhance 

compliance and enforcement of these 

rules to assure that the emission 

reductions necessary for expeditious 

attainment are achieved. This 

commitment is an important component 

of our proposed finding that the Clark 

County Plan provides for 

implementation of BACM and inclusion 

of MSM. 

We also have evaluated the rules for 

enforceability and consistency with 

applicable CAA requirements for SIP 

revisions in section 110 and Part D and 

EPA rulemaking policy. 

a. Disturbed Vacant Land 

This category includes windblown 

fugitive dust emissions from disturbed 

surfaces of vacant land. On vacant land, 

fugitive dust emissions are caused by 

virtually any activity which disturbs an 

otherwise naturally stable parcel of 

land, including earth-moving activities, 

material dumping, weed abatement, and 

vehicle traffic. Wind erosion from 

disturbed vacant land accounts for 45 

percent of total PM–10 emissions in the 

1998 24-hour BLM Disposal Area 

inventory and 39 percent of total PM–

10 emissions in the 1998 annual BLM 

Disposal Area valley-wide inventory,

2960 Federal Register / Vol. 68, No. 14 / Wednesday, January 22, 2003 / Proposed Rules 

12Constructing windbreaks was also identified 

but deemed less stringent than surface stabilization. 

Therefore, the benefits of applying this potential 

BACM are subsumed in the more stringent emission 

reductions associated with surface stabilization. In 

addition, Clark County identified weed abatement 

on vacant land as a separate category. Since this 

pertains to ‘‘surface stabilization’’ we include it 

under that category; however, weed abatement by 

discing and blading also generates emissions as the 

activity is being conducted, therefore, Clark County 

has adopted separate requirements for weed 

abatement in its vacant lot rule.

13We note that section 90 requirements apply 

throughout the entire PM–10 nonattainment area.

14Standards include a visible crust 

determination, 20% cover of nonerodible elements, 

or a threshold friction velocity (corrected for 

nonerodible elements) of 100 cm/sec or higher.

15Clark County submitted a SIP amendment that 

establishes a revised deadline of March 31, 2003 for 

the section 90 and other rule revisions. 16See Clark County Plan, Chapter 4, subsection 

4.5.2.2.5. 17Clark County submitted a SIP amendment that 

establishes a revised deadline of March 31, 2003 for 

the section 92 and other rule revisions.

18Adoption of a requirement prohibiting new 

unpaved parking lots, in addition to the section 92 

stabilization requirements, collectively fulfill 

BACM and MSM. However, since the section 92 

surface stabilization requirements apply to both 

new and existing unpaved parking lots, the 

requirement that new lots be paved provides only 

incremental emission reductions beyond measures 

already adopted and, therefore, is not critical in our 

determination that measures for this source 

category have been adopted as expeditiously as 

practicable.

19Both a 20% opacity standard according to a 

modified EPA Reference Method 9 and a silt 

content standard of 8% or alternatively, a silt 

loading standard of 0.33 oz/sq. ft., apply.

making it the largest source of PM–10 in 

the Las Vegas area.

The suggested measures for 

controlling emissions from disturbed 

vacant land fall into one of two 

categories: preventing motor vehicle 

disturbance of vacant land, and 

stabilizing vacant land.12 We propose to 

find that the Clark County Plan 

evaluates a comprehensive set of 

potential controls for disturbed vacant 

land including the potential MSM from 

other States.

Clark County implemented both 

access prevention and surface 

stabilization with specific requirements 

in section 90 ‘‘Fugitive Dust From Open 

Areas and Vacant Lots’’. Section 90 

requires prevention of motor vehicles 

(including off-road vehicles), where 

there is evidence of such use, on open 

areas and vacant lots greater than or 

equal to 5,000 square feet by installation 

of barriers or other effective traffic 

control measures and stabilization of 

motor-vehicle disturbed surfaces on 

such lots. Also, where 5,000 square feet 

or more of cumulative disturbed surface 

exists (from any activity) all disturbed 

areas must be stabilized using water, 

dust palliatives or gravel. When discing 

or blading areas of 5,000 square feet or 

more, water must be applied before and 

during operations and the disturbed 

surface stabilized afterwards. 

The requirements apply to public and 

private vacant land alike. Clark County 

determined that less than one percent of 

vacant land within the BLM Disposal 

Boundary 13 consists of parcels smaller 

than 5,000 square feet, thus the 

requirements provide a stringent 

threshold of applicability. Section 90 

contains appropriate performance 

standards and test methods for surface 

stability,14 recordkeeping requirements, 

and otherwise meets EPA’s 

enforceability criteria.

Clark County has also made a SIP 

commitment to adopt a requirement for 

dust management plans on large tracts 

(i.e., 10,000 acres or more) of 

government owned land.15

Section 90 vacant lot requirements 

became effective on January 1, 2001. We 

propose to find that the Clark County 

Plan provides for the implementation of 

vacant lot measures as expeditiously as 

practicable, consistent with our 

proposed MSM policy. 

For the MSM analysis, Clark County 

demonstrated that the section 90 

requirements are of equivalent or greater 

stringency than those adopted or in 

practice in other areas. 

We, therefore, propose to find that the 

Clark County Plan provides for the 

implementation of BACM and for the 

inclusion of MSM for disturbed vacant 

land. We also propose approval of 

section 90 into the SIP in accordance 

with CAA section 110 and the 

requirements of CAA Title I, part D. 

b. Unpaved Parking Lots 

This category includes emissions from 

re-entrained road dust from vehicle 

traffic on unpaved parking lots and 

windblown dust entrained from the 

disturbed surface of unpaved parking 

lots. Windblown emissions from 

unpaved parking lots are included in 

the disturbed vacant land category in 

the 1998 base year valley-wide and BLM 

Disposal Area emissions inventories. 

The extent of unpaved parking lots 

affected by the controls in adopted Rule 

92 has not been determined (or credited) 

on a valley-wide inventory basis,16 but 

instead only with respect to the 

microscale inventories.

There are two principal ways to 

control emissions from unpaved parking 

lots, both of which Clark County 

identified: prohibit unpaved parking 

lots or stabilize existing lots. We 

propose to find that the Clark County 

Plan evaluates a comprehensive set of 

potential controls for unpaved parking 

lots including the potential MSM from 

other States. 

Clark County adopted requirements to 

stabilize existing unpaved parking lots 

in section 92 ‘‘Fugitive Dust From 

Unpaved Parking Lots.’’ Clark County 

also adopted a SIP commitment to 

modify section 92 to prohibit new 

unpaved parking lots with limited 

exceptions.17 Therefore, both potential 

BACM have or will shortly be 

adopted.18

Section 92 requires that all unpaved 

parking lots greater than or equal to 

5,000 square feet be stabilized by 

application of paving, dust palliatives, 

or a combination of dust palliatives in 

the travel lanes and two inches of 

gravel. Lots used intermittently (thirtyfive days per year or less), must be 

stabilized according to section 92 

standards only on days of use. On days 

of inactivity, however, such lots are 

subject to section 90 standards.

The section 92 requirements apply to 

both public and private unpaved 

parking lots. The analysis Clark County 

used to assess the percentage of vacant 

land parcels smaller than 5,000 square 

feet in the BLM Disposal Area applies 

to unpaved parking lots as well. Section 

92 contains appropriate performance 

standards and test methods for surface 

stability and opacity,19 recordkeeping 

requirements, and otherwise meets 

EPA’s enforceability criteria.

Section 92 unpaved parking lot 

requirements became effective on 

January 1, 2001. We propose to find that 

the Clark County Plan provides for the 

implementation of unpaved parking lot 

measures as expeditiously as 

practicable, consistent with our 

proposed MSM policy. 

For the MSM analysis, Clark County 

demonstrated that the section 92 

requirements are more stringent than 

those adopted or in practice in other 

areas. We, therefore, propose to find that 

the Clark County Plan provides for the 

implementation of BACM and for the 

inclusion of MSM for unpaved parking 

lots. We also propose SIP approval of 

section 92 per CAA section 110 and Part 

D. 

c. Construction Sites 

Sources of fugitive dust emissions at 

construction sites include land clearing, 

earthmoving, excavating, construction, 

demolition, material handling, bulk 

material storage and/or transporting 

operations, material track out or spillage 

onto paved roads (which we have 

addressed in the paved road section), 

and vehicle use and movement on site 

(e.g., the operation of any equipment on 

unpaved surfaces, unpaved roads and

Federal Register / Vol. 68, No. 14 / Wednesday, January 22, 2003 / Proposed Rules 2961

20We do not consider improved enforcement a 

BACM but rather a method of implementing BACM.

21The Section 94 Handbook and associated 

documents are explicitly adopted as part of section 

94 per subsection 94.3.1 of the rule.

22Five soil type categories are included that take 

into account both silt content and optimum 

moisture content: high, moderately high, 

moderately low, low and slight. The high and 

moderately high soils generally require that a 

surfactant mixture with water or tackifyer mixture 

with water, respectively, be applied for effective 

dust control.

23Construction activities with specific BMPs 

include trenching, truck loading, screening, 

landscaping, paving/subgrade preparation, 

disturbed inactive surfaces, track out control, 

staging, equipment, and material storage areas, 

construction traffic, crushing, abrasive blasting, soil 

and rock blasting, stockpiles, importing bulk 

materials, backfilling, clearing and grubbing, 

clearing forms, cut and fill and demolition.

24Surfaces must comply with a visible crust 

standard per the test method in section 94 but may 

also comply with other surface stability standards 

in section 90.

25A modified EPA Reference Method 9 applies, 

found in section 91.

26A 6 percent silt content and/or 0.33 oz per 

square foot silt loading standard applies.

27This requirement was newly developed by 

Clark County and serves the dual purpose of 

improving compliance of larger sites by active 

monitoring of dust control-related efforts, but also 

encourages owners/operators to keep the total 

amount of disturbed surface under 50 acres as a 

preventative measure.

unpaved parking areas). Windblown 

emissions from disturbed areas and 

inactive storage piles on construction 

sites are also a source of PM–10. 

Construction operations, which are 

mostly earthmoving, represent 

approximately 37 percent of the 24-hour 

BLM Disposal Area emissions (not 

including trackout emissions). 

The suggested measures in the Clark 

County Plan for controlling emissions 

from constructions sites include a 

detailed list of controls encompassing a 

great variety of dust-generating 

activities, performance standards, 

enforcement-related measures,20 and 

new measures not implemented in other 

areas. The measures considered include 

all sources of active dust generation and 

windblown dust on construction sites. 

We propose to find that the Clark 

County Plan evaluates a comprehensive 

set of potential controls for construction 

sites emissions including the potential 

MSM from other States.

Clark County adopted requirements 

pertaining to construction sites in 

Section 94 ‘‘Permitting and Dust Control 

for Construction Activities’’ on 

November 16, 2000. As part of this 

action, Clark County also adopted a 

‘‘Section 94 Handbook,’’ along with 

relevant tables of contents, definitions, 

articles, tables, indexes, examples and 

appendices.21 Together these 

documents make up the required 

control measures applicable to 

construction sites. Section 94 

establishes the basic requirements for 

construction site dust control permits 

and other standards while the Section 

94 Handbook lays forth more specific 

requirements for each dust-generating 

source.

Dust control permits are required 

prior to soil disturbance for all sites 

greater than 1⁄4 acre, mechanized 

trenching greater than 100 feet in length, 

and mechanical demolition of structures 

greater than 1,000 square feet. However, 

all sites with construction activities 

regardless of size are subject to the 

requirements of section 94 and the 

Section 94 Handbook. Dust control 

permits must contain a ‘‘Dust Mitigation 

Plan’’ that employs the Section 94 

Handbook Best Management Practices 

(BMPs). The Section 94 Handbook 

requirements are not only activityspecific and designed to be placed into 

dust control permits in a phase-specific 

manner, but are also specific to the type 

of soil at a particular site or location and 

the soil’s potential to emit fugitive dust. 

Therefore, each Dust Mitigation Plan 

must incorporate the appropriate BMPs 

per the Section 94 Handbook according 

to soil type parameters.22 Sites 10 acres 

or greater must provide a more detailed 

project description and site plan 

according to a ‘‘Site Specific Dust 

Mitigation Plan’’.

The Section 94 Handbook establishes 

a specific performance standard (i.e., 

Control Requirement) that must be met 

for each identified construction 

activity.23 Multiple Control 

Requirements apply for each 

construction activity. A menu of control 

measure options is provided, one or 

more of which must be specifically 

identified in the Dust Mitigation Plan to 

meet each applicable Control 

Requirement for the activity. The 

control measures identified in the Dust 

Mitigation Plan are subject to review 

and approval by the DAQM as part of 

the dust control permit.

Specific requirements include a 20 

percent opacity standard for active 

earthmoving operations and 

construction traffic. Also, all 

construction activities are prohibited 

from creating a visible plume that 

extends more than 100 yards from the 

point of origin. Construction site 

trackout is addressed by both a 

requirement to install and maintain 

trackout control devices at all traffic 

access/exit points and a requirement 

that trackout be cleaned up immediately 

(within one hour of discovery) if it 

extends a cumulative distance of 50 feet 

or more. In addition, all trackout must 

be cleaned up by the end of the work 

day or evening shift. To prevent 

emissions during bulk material 

transport and handling, truck loads 

must be covered on public roads and a 

20 percent opacity limit applies during 

truck loading and unloading. Truck 

loads of bulk materials on site must 

either be covered, maintain three to six 

inches of freeboard, or maintain 

optimum moisture content of soils. All 

inactive disturbed soil areas must meet 

surface stabilization standards, 

including stockpiles and parking 

areas.24 Unpaved haul roads must 

comply with both a 20% opacity 

standard 25 and a surface stabilization 

standard.26 In high wind conditions, 

owners/operators must cease all 

construction activities if fugitive dust 

exceeds 20 percent opacity but must 

continue operation of water trucks and 

pulls except under specific 

circumstances. Sites with greater than 

50 acres of actively disturbed soil are 

required to employ a responsible person 

to monitor dust control at the site.27

Section 94 and the Section 94 

Handbook and other documents 

adopted by reference contain 

appropriate performance standards and 

test methods for opacity and surface 

stability, recordkeeping requirements, 

and otherwise meet EPA’s enforceability 

criteria. Although the opacity standard 

per the test method included in section 

94 is the best currently available to 

assess the opacity of emissions from the 

variety of construction activities 

generating fugitive dust, it may not be 

sufficient in all field circumstances to 

control intermittently-occurring dust 

plumes to BACM levels. Therefore, 

Clark County has adopted a SIP 

commitment to fund additional research 

to develop an acceptable alternative test 

method and revise section 94 

accordingly. See Chapter 4 of the Plan, 

section 4.8.2.7. We consider this 

commitment as factoring into our 

determination that the Plan provides for 

BACM/MSM. 

Section 94 construction site 

requirements became effective on 

January 1, 2001. We propose to find that 

the Clark County Plan provides for the 

implementation of construction site 

measures as expeditiously as 

practicable, consistent with our 

proposed MSM policy.

For the MSM analysis, Clark County 

demonstrated that the section 94 and 

section 94 Handbook requirements are 

of equivalent or greater stringency than 

those adopted or in practice in other 

areas. 

We, therefore, propose to find that the 

Clark County Plan provides for the

2962 Federal Register / Vol. 68, No. 14 / Wednesday, January 22, 2003 / Proposed Rules 

28Reductions in vehicle miles traveled and 

vehicle trips are also candidate transportation 

control measures (TCMs) that could have positive 

impacts on reducing paved road dust. However, 

these measures are more appropriate for areas 

addressing significant on-road mobile source 

emissions and would not impact paved road dust 

on the same magnitude as measures directed 

towards preventing or removing deposition. TCMs 

are separately addressed and included in Clark 

County’s Carbon Monoxide Plan, adopted on 

August 1, 2000.

29Clark County submitted a SIP amendment that 

establishes a revised deadline of March 31, 2003 for 

the section 93 and other rule revisions.

30Prevention of storm water drainage deposits, 

cleanup of material spills and erosion-caused 

deposits, and routine sweeping of paved roads.

31See Clark County Plan, Appendix J and Chapter 

4, pg. 4–69.

32For example, a large portion of the publiclyowned street sweeping fleet already consisted of 

PM–10 efficient street sweepers in 1998 and routine 

sweeping programs were already in place.

33This refers to a street sweeper which has been 

certified by the South Coast Air Quality 

Management District (SCAQMD) to comply with the 

performance standards in SCAQMD’s Rule 1186 

according to test methods specified in Rule 1186.

34Clark County has made a SIP commitment to 

strengthen this provision to provide for eight feet 

of stabilized shoulder adjacent to the paved travel 

section on roads with 3,000 vehicles per day or 

more. The new SIP commitment date of March 31, 

2003 applies per Clark County’s SIP amendment.

implementation BACM and for the 

inclusion of MSM for construction sites. 

We also propose SIP approval of section 

94 and the section 94 Handbook and 

referenced documents per CAA section 

110 and part D. 

d. Paved Road Dust 

Paved road dust is fugitive dust that 

is deposited on a paved roadway and 

then re-entrained into the air by the 

action of tires grinding on the roadway. 

Dust can be deposited on the roadway 

from being blown onto the road from 

disturbed areas, tracked onto the road 

from unpaved shoulders, unpaved 

roads, or other unpaved access points, 

stirred up from unpaved shoulders by 

wind currents created from traffic 

movement, spilled onto the road by haul 

trucks, and carried onto the road by 

water runoff or erosion. Paved road dust 

constitutes 26 percent of the 1998 

valley-wide annual BLM Disposal Area 

emissions, thus is the second largest 

source of valley-wide PM–10 in the Las 

Vegas area. Paved road dust accounts for 

13 percent of the overall 24-hour BLM 

Disposal Area 1998 inventory. 

The suggested measures for 

controlling emissions from paved road 

dust fall into two categories: Preventing 

deposition of material onto a roadway, 

and cleaning material off the roadway.28

The Clark County Plan includes ten 

potential BACM for paved road dust 

that fall under one of these two 

categories. We believe this list is 

complete and propose to find that the 

Clark County Plan evaluates a 

comprehensive set of potential controls 

for paved road dust including the 

potential MSM from other States.

Clark County adopted requirements 

for paved road shoulders and PM–10 

efficient street sweeping requirements 

in section 93 ‘‘Fugitive Dust from Paved 

Roads and Street Sweeping Equipment’’. 

Clark County adopted SIP commitments 

to stabilize existing unpaved road 

shoulders and require use of vacuum 

crack seal equipment. See Clark County 

Plan, Chapter 4, sections 4.8.3.2 and 

4.8.2.9.29 Measures to prevent 

construction site trackout onto paved 

roads from truck tires and material 

transport are included in section 94 and 

the section 94 Handbook (construction 

activity regulations). For other 

measures 30, Clark County provided 

documentation of ongoing programs in 

place.31

The paved road measures relied upon 

for emissions reductions towards 

demonstrating attainment include 

stabilizing unpaved road shoulders, 

preventing trackout from construction 

sites, and reducing deposition from 

other fugitive dust sources subject to 

control per sections 90 through 94. The 

remaining measures are either already 

factored into the baseline or are not 

credited with emissions reductions 

towards the attainment 

demonstration.32

Section 93 requires owners/operators 

using street sweeping equipment or 

services on paved roads or parking lots 

to acquire or contract to acquire only 

certified PM–10 efficient street 

sweeping equipment 33 after January 1, 

2001. We note this requirement applies 

to both private operators and 

government agencies.

For new or modified road shoulders, 

section 93 requires four feet of paved or 

stabilized shoulder on each side of the 

paved travel section or construction of 

curbing adjacent to the paved travel 

lane.34 Medians must also be stabilized.

For existing unpaved road shoulders, 

section 93 requires stabilization within 

365 days following initial discovery that 

the road fails to meet the stabilization 

standards and other requirements that 

apply to new/modified paved road 

shoulders. The stringency of this 

provision is necessarily enhanced by the 

SIP commitment in the Plan which lays 

forth the program and definitive dates 

by which all unstabilized shoulders will 

be identified and stabilized by public 

agencies in the Valley. Clark County 

indicates that shoulder improvements 

will be prioritized by each entity for 

their respective jurisdictions based 

upon emissions estimates. To 

implement the program, Plans will be 

completed by February 15, 2002, and at 

a minimum, funds will be obligated to 

improve 33 miles of paved road 

shoulders by the end of 2003, with all 

shoulders to be stabilized by the end of 

2006. Annual updates on the progress of 

stabilizing shoulders will be submitted 

to Clark County and EPA. In a June 28, 

2002 letter, the DAQM indicates that the 

respective public entities have 

submitted initial plans for stabilizing 

shoulders and initiated programs to 

begin stabilization.

Section 93, paved road requirements, 

became effective on January 1, 2001. 

The SIP commitment by governmental 

entities to stabilize 33 miles of unpaved 

shoulders by the end of 2003 and all 

shoulders by the end of 2006 allows 

time for public works agencies to 

complete an inventory of the unpaved 

shoulders in their respective 

jurisdictions and adopt schedules under 

capital improvement programs to 

stabilize shoulders each year using 

Congestion Management Air Quality 

(CMAQ) funds. Other measures have ongoing implementation schedules 

because they are part of an on-going 

capital improvement program, e.g., 

storm water drainage projects. 

Therefore, we propose to find that the 

Clark County Plan provides for the 

implementation of paved road measures 

as expeditiously as practicable, 

consistent with our proposed MSM 

policy. 

For the MSM analysis, Clark County 

demonstrated that the section 93 

requirements and SIP commitments 

contained in the Plan are of equivalent 

or greater stringency than those adopted 

or in practice in other areas. 

We, therefore, propose to find that the 

Clark County Plan provides for the 

implementation of BACM and for the 

inclusion of MSM for paved road dust. 

e. Unpaved Roads 

This category includes re-entrained 

dust from vehicle travel on unpaved 

roads and windblown emissions from 

unpaved roads. There are three 

categories of unpaved roads in the Clark 

County nonattainment area: Publiclyowned/maintained roads, privatelyowned roads, and unpaved haul/access 

roads associated with construction sites 

or industrial facilities. We have 

addressed the latter category in the 

discussion of construction site measures 

(section IV.D.3.c) of this document. 

There are three ways to control 

fugitive dust emissions from unpaved 

roads: surface treatment to reduce dust 

from unpaved roads and alleys, traffic 

reduction/speed control plans for 

unpaved roads, and prohibition of

Federal Register / Vol. 68, No. 14 / Wednesday, January 22, 2003 / Proposed Rules 2963

35However, traffic reduction/speed control is 

included in the Section 94 Handbook as a BMP for 

unpaved haul/access construction site roads.

36See Chapter 4, section 4.8.3.1 of the Plan.

37See Chapter 4, section 4.8.3.2 of the Plan.

38See Chapter 4, section 4.8.2.3 of the Plan.

39Where paving is not conducted (this would 

only apply to roads that are not included in the SIP 

commitment by Public Works entities), both a 20% 

opacity standard according to a modified EPA 

Reference Method 9 and a silt content standard of 

6% or alternatively, a silt loading standard of 0.33 

oz/sq. ft., apply.

40See Chapter 7, pg. 7–4 of the Plan.

41See Chapter 4, pg. 4–81 of the Plan.

unpaved haul roads. All three are 

identified and evaluated in the Clark 

County Plan. We believe this list is 

complete and propose to find that the 

Clark County Plan evaluates a 

comprehensive set of potential BACM 

and MSM for unpaved roads. 

Clark County did not implement 

traffic reduction/speed control on 

public and private roads in the Valley.35

This is because the County determined 

that reducing traffic on public and 

private unpaved roads is not as stringent 

a measure as paving or other means of 

surface stabilization. Speed control is 

difficult to enforce compared to road 

paving, which can be readily verified 

and results in greater emissions 

reductions. Thus, the benefits of 

applying this potential BACM are 

subsumed in the more stringent 

emission reductions associated with 

surface stabilization.

Clark County adopted requirements to 

stabilize existing unpaved roads and 

alleys and to prohibit new unpaved 

roads in public thoroughfares in section 

91 ‘‘Fugitive Dust From Unpaved Roads, 

Unpaved Alleys and Unpaved Easement 

Roads.’’ Also, Clark County adopted a 

SIP commitment for County and City 

Public Works agencies to pave unpaved 

roads subject to section 91.36

Section 91 requires all existing 

unpaved roads that receive 150 vehicle 

trips per day or more to be paved or 

treated with dust palliatives on the 

following schedule: 1⁄3 of the total by 

June 2001, two-thirds of the total by 

June 2002, and any remaining roads by 

June 1, 2003. Section 91 prohibits 

construction of new unpaved roads or 

alleys in public thoroughfares after June 

22, 2000 unless the unpaved road is an 

interim component of an active paving 

project. 

Section 91 requirements apply to both 

public and private roads. Clark County 

estimates that approximately 64 miles of 

the 259-mile total base year inventory of 

publicly-owned and maintained 

unpaved roads have 150 or more 

average daily vehicle trips (ADT). The 

unpaved roads inventory was developed 

by the respective Public Works 

departments after extensive review of 

the existing road network. Given that 

higher ADT unpaved roads 

proportionately contribute greater 

emissions than lower ADT roads, the 64 

miles constitute 66% of emissions from 

the total inventoried road network. The 

SIP commitment for unpaved roads 

made by County and City Public Works 

agencies not only goes beyond the 

section 93 requirements in that it 

ensures roads will receive the maximum 

emissions reductions possible through 

paving, but further enhances coverage in 

that the City of Las Vegas makes an 

additional commitment to pave all 

unpaved roads within its jurisdiction by 

the end of 2006. We also note that the 

SIP commitment concerning paved road 

shoulders 37 indicates that shoulder 

improvements and road paving for 

unpaved roads with less than 150 ADT 

will be prioritized by each entity for 

their respective jurisdictions based 

upon emissions estimates. Thus, road 

paving efforts by jurisdictions may very 

well go beyond the requirements in 

section 91 depending on the availability 

of CMAQ dollars. Section 91 contains 

specific reporting requirements for the 

responsible jurisdictions and the SIP 

commitment for unpaved roads 

provides for annual progress updates to 

be provided to the DAQM and EPA.

While the miles of privately owned 

unpaved roads have not been fully 

inventoried in detail, a total of 45 miles 

of private roads were identified by 

various municipalities and the County, 

none of which were determined to have 

traffic volumes greater than 50 ADT. 

Clark County included a SIP 

commitment in the Plan to develop an 

improved inventory of both public and 

private unpaved roads.38

Section 91 also contains requirements 

that address the prospect of vehicle 

traffic increases on unpaved roads that 

are currently below the 150 ADT 

threshold but in the future exceed it. 

Any existing unpaved roads which 

equal or exceed 150 ADT after June 1, 

2003 are subject to control according to 

section 91 within 365 calendar days 

following initial discovery that 

vehicular traffic equals or exceeds 150. 

Section 91 contains appropriate 

performance standards and test methods 

for surface stability and opacity,39

recordkeeping requirements, and 

otherwise meets EPA’s enforceability 

criteria. 

Section 91 unpaved road 

requirements prohibit new unpaved 

roads as of June 22, 2000. Clark County 

indicates that the CMAQ funding 

obligated by the responsible government 

agencies (totaling over $25 million) will 

support completing approximately onethird of the total paving requirement in 

section 91 for each year from 2001 to 

2003.40 Moreover, we note in a June 28, 

2002 letter from the DAQM that the 

responsible jurisdictions have exceeded 

the section 91 required one-third 

increment of road paving by June 2001 

and have reported paving 86 percent, or 

a total of 55 of the 64-mile public road 

inventory receiving 150 ADT or more. 

This demonstrates the commitment of 

Clark County governmental entities to 

implement control measures 

expeditiously. We propose to find that 

the Clark County Plan provides for the 

implementation of unpaved road 

measures as expeditiously as 

practicable, consistent with our 

proposed MSM policy.

For the MSM analysis, Clark County 

demonstrated that the section 91 

requirements and SIP commitments for 

unpaved roads are equally or more 

stringent than those adopted or in 

practice in other areas. 

We, therefore, propose to find that the 

Clark County Plan provides for the 

implementation of BACM and for the 

inclusion of MSM for unpaved roads. 

We also propose SIP approval of section 

91 per CAA section 110 and part D.

f. Race Tracks 

Race track emissions are both actively 

generated from use by offroad vehicles, 

e.g., dirt bikes and all-terrain vehicles 

(ATVs), and windblown from disturbed 

surfaces following use. Clark County 

determined that race track emissions are 

only significant with respect to the 24-

hour standard. Race track emissions that 

were found to have significant impacts 

at two micro-inventory sites were 

associated with unauthorized ATV use 

on a vacant parcel.41

Clark County did not prepare a 

separate BACM analysis for race tracks. 

Rather, Clark County implements its 

strategy for race tracks through section 

90 controls for disturbed vacant land 

and open areas. We note that there are 

three potential BACM for control of dirt 

race tracks: Prohibit race tracks, treat the 

surface of race tracks with dust 

suppressants or palliatives, and 

establish wind breaks around the 

circumference of tracks. Of these 

potential BACM, Section 90 controls 

address the first two. Establishing wind 

breaks has not been adopted, but this 

measure is not as stringent as 

prohibiting race tracks and surface 

treatment of disturbed areas. 

Clark County determined that section 

90 requirements effectively prohibit dirt 

race tracks because it is not possible to

2964 Federal Register / Vol. 68, No. 14 / Wednesday, January 22, 2003 / Proposed Rules 

operate off-road vehicles, including dirt 

bikes and ATVs, on open areas/vacant 

lots and remain in compliance with the 

regulation. Where motor vehicle 

trespass is occurring on vacant lots 

greater than 5,000 square feet, owners 

must take steps to prevent trespass and 

stabilize the surface. Even if motor 

vehicle use is authorized, where over 

5,000 cumulative square feet of surface 

has been disturbed, owners/operators 

must apply dust palliative (other than 

water) or gravel. These requirements 

would apply to any public or private 

lands where offroad racing occurs. 

The one public entity in Clark County 

that can effectively authorize use of 

public land for offroad racing events is 

the Bureau of Land Management. Clark 

County indicates that BLM is currently 

working to establish offroad racing 

courses outside the nonattainment area. 

The DAQM’s policy prohibiting 

issuance of permits for offroad race 

tracks within the nonattainment area is 

described in a letter dated September 5, 

2002 from the DAQM to the BLM and 

in letters from the DAQM to other 

public agencies dated September 9, 

2002. 

Clark County did not conduct a MSM 

evaluation specific to race tracks. 

Rather, the MSM evaluation for section 

90 applies. We propose to find that the 

Clark County Plan provides for the 

implementation of BACM and for the 

inclusion of MSM for race tracks. 

g. Section 0 

Section 0 was revised by Clark County 

at the same time sections 90 through 94 

were originally adopted (November 16, 

2000). The section 0 definitions that 

concern fugitive dust sources are 

integrally linked to the requirements 

found in sections 90 through 94. 

However, section 0 also contains 

definitions that are not pertinent to 

sections 90 through 94. For the purposes 

of this action, we have only evaluated 

the definitions concerning fugitive dust 

sources per section 90 through 94 

requirements and are proposing to 

approve only these sections into the SIP, 

rather than the entire section 0. 

The individual sections of section 0, 

November 16, 2000, we are proposing to 

approve into the Nevada PM–10 SIP 

include the following:

Section 0.25 ‘‘Best Management 

Practices’’

Section 0.33 ‘‘Commercial and 

Residential Construction’’

Section 0.36 ‘‘Construction Activity’’

Section 0.37 ‘‘Control Measure’’

Section 0.43 ‘‘Disturbed Surface 

Area’’

Section 0.45 ‘‘Dust Palliative’’

Section 0.46 ‘‘Dust Suppressant’’

Section 0.47 ‘‘Easement’’

Section 0.48 ‘‘Easement Holder’’

Section 0.51 ‘‘Emergency’’

Section 0.58 ‘‘EPA or Administrator’’

Section 0.65 ‘‘Flood Control 

Construction’’

Section 0.70 ‘‘Fugitive Dust’’

Section 0.81 ‘‘Hearing Officer’’

Section 0.84 ‘‘Highway Construction’’

Section 0.110 ‘‘Nonroad Easement’’

Section 0.111 ‘‘Normal Farm Cultural 

Practice’’

Section 0.114 ‘‘Offroad Vehicle’’

Section 0.117 ‘‘Open Areas and 

Vacant Lots’’

Section 0.120 ‘‘Owner and/or 

Operator’’

Section 0.127 ‘‘Pave’’

Section 0.132 ‘‘PM–10 Nonattainment 

Area’’

Section 0.133 ‘‘PM–10’’

Section 0.140 ‘‘Public Road’’

Section 0.141 ‘‘Reclaimed Water’’

Section 0.147 ‘‘Road Easement’’

Section 0.162 ‘‘Trench’’

Section 0.164 ‘‘Unpaved Parking Lot’’

Section 0.166 ‘‘Vacant Lot’’

The current Nevada SIP contains a 

definitions rule titled ‘‘Section 1—

Definitions’’ submitted on November 17, 

1981 and approved into the SIP by EPA 

on June 21, 1982. Our proposed 

incorporation of the specified section 0 

definitions into the SIP would upgrade 

the SIP by adding several new 

definitions and by replacing two of the 

existing section 1 definitions. These two 

definitions include section 0.70 

‘‘Fugitive Dust’’ and section 0.114 

‘‘Offroad Vehicle’’, which would replace 

subsection 1.35 and subsection 1.64 of 

section 1, respectively. 

G. Applicable SIP Rules 

In addition to section 1, the 

applicable SIP-approved fugitive dust 

rules that apply in Clark County include 

section 41 ‘‘Fugitive Dust’’ (submitted 

on July 24, 1979 and approved by EPA 

on August 27, 1981) and section 17 

‘‘Permission to Disturb Topsoil’’

(submitted on July 24, 1979 and 

approved by EPA on August 27, 1981). 

Revisions to section 17 were submitted 

on November 17, 1981 and approved by 

EPA on June 18, 1982. 

We are proposing to revise the Nevada 

PM–10 SIP to incorporate sections 90, 

91, 92, 93 (as adopted on November 20, 

2001) and section 94 (including the 

Section 94 Handbook and other 

referenced documents) (as adopted on 

November 16, 2000) of the Clark County 

Regulations. We are proposing to 

replace SIP-approved Clark County 

section 17. We are also proposing to add 

certain portions of Section 0 (as adopted 

on November 16, 2000) to the existing 

SIP-approved section 1, and replace two 

definitions in section 1, as previously 

identified in this notice. 

CAA section 110(l) prohibits approval 

of SIP revisions that would interfere 

with any applicable requirement 

concerning attainment and RFP or any 

other applicable requirement of the Act. 

As discussed in other sections of this 

document, we are proposing to approve 

the expeditious attainment and RFP 

demonstrations in the PM–10 State 

Implementation Plan for Clark County. 

These demonstrations are in large part 

dependent on approval of sections 90, 

91, 92, 93, and 94 (including Handbook) 

and Clark County SIP commitments. 

Therefore, our proposed approval of 

these rules and SIP commitments will 

not adversely affect the Plan’s 

provisions for expeditious attainment 

and RFP. These SIP revisions also 

satisfy all other applicable CAA 

requirements including implementation 

of BACM and the inclusion of MSM. 

H. General SIP Requirements and 

Enforcement of Fugitive Dust Rules 

Section 110(a)(2)(E)(i) of the Clean Air 

Act requires that the implementation 

plan provide necessary assurances that 

the State (or the general purpose local 

government) will have adequate 

personnel, funding and authority under 

State law. Requirements for legal 

authority are further defined in 40 CFR 

part 51, subpart L (51.230–51.232) and 

for resources in 40 CFR 51.280. 

States and responsible local agencies 

must demonstrate that they have the 

legal authority to adopt and enforce 

provisions of the SIP and to obtain 

information necessary to determine 

compliance. SIPs must also describe the 

resources that are available or will be 

available to the State and local agencies 

to carry out the plan, both at the time 

of submittal and during the 5-year 

period following submittal. 

Section 110(a)(2)(C) of the Act 

requires SIPs to include a program to 

provide for the enforcement of SIP 

measures. The implementing regulation 

for this section is found at 40 CFR 

51.111(a) and requires control strategies 

to include a description of enforcement 

methods including (1) procedures for 

monitoring compliance with each of the 

selected control measures, (2) 

procedures for handling violations, and 

(3) the designation of the agency 

responsible for enforcement. 

Section 110(a)(2)(E)(iii) of the Act 

requires SIPs to include necessary 

assurances that where a State has relied 

on a local or regional government, 

agency or instrumentality for the 

implementation of any plan provision, 

the State has responsibility for ensuring

Federal Register / Vol. 68, No. 14 / Wednesday, January 22, 2003 / Proposed Rules 2965

42See June 28, 2002 letter and attached RFP 

Report and October 1, 2002 letter from the DAQM 

to EPA.

adequate implementation of the such 

plan provision. 

With respect to CAA section 

110(a)(2)(E)(iii), the State of Nevada has 

ultimate responsibility for ensuring the 

adequate implementation of the Clark 

County air quality program according to 

NRS 445B.520. This statute allows the 

State Environmental Commission to 

supersede a County’s program when the 

Commission determines that a local air 

quality program is inadequate. 

The principal control measures in the 

Clark County Plan are the adopted 

requirements in sections 90 through 94 

and the Plan’s SIP commitments for 

unpaved shoulders and roads. 

1. Staffing 

Clark County has committed to 

increase its enforcement staffing and 

thus enhance enforcement efforts. See 

Chapter 4, section 4.8.1 and appendix 

H, Resolution 02–00, July 27, 2001, of 

the Clark County Plan. Specifically, 

Clark County committed to hire 15 

additional staff by December 31, 2001 to 

implement and enforce sections 90 

through 94, including several 

enforcement officers, clerical and other 

support positions. Prior to the 

fulfillment of this SIP commitment, 

compliance for fugitive dust sources 

(per sections 17 and 41 of the Clark 

County Regulations) was being handled 

by 11 people total, seven (7) of which 

were field enforcement officers 

conducting inspections.

The DAQM has provided us with the 

status of its SIP commitments.42 First, 

the DAQM met its commitment by 

hiring 15 new staff into the compliance 

division, 12 of which were hired as field 

enforcement officers to conduct 

inspections and handle cases for 

construction sites and vacant lots. The 

DAQM then exceeded its SIP 

commitment by hiring an additional 

seven (7) field enforcement officers in 

2002. The Compliance Division now 

consists of a total of 44 positions, with 

22 field enforcement officers who spend 

approximately 90 percent of their time 

on fugitive dust issues. The increased 

level of effort specifically being targeted 

towards fugitive dust sources is 

evidenced by the significant number of 

inspections and corrective action orders 

concerning fugitive dust sources in 2001 

and 2002, which we address in 

subsequent paragraphs.

We address below other program 

areas that are key to improving 

compliance and which we believe form 

a solid program for the effectiveness of 

the County’s efforts to control fugitive 

dust. 

2. Inspection Program 

Clark County’s enforcement staff 

utilizes the county Geographic 

Information System (GISMO) to obtain 

detailed aerial photographs to locate 

and identify large parcels of vacant land 

to inspect and characterize. The DAQM 

continues to expand the existing vacant 

land program by identifying and 

systematically inspecting the problem 

areas and the larger parcels. 

In calendar years 2001 and 2002 (as 

of September) combined, Clark County 

has conducted over 4,000 vacant land 

inspections. The Compliance Division 

has a member on staff who coordinates 

all activities and concerns with two 

government agency large vacant 

landowners, the Bureau of Land 

Management and the Bureau of 

Reclamation—in order to ensure close 

cooperation with these agencies. 

In calendar years 2001 and 2002 (as 

of September) combined, Clark County 

has conducted over 5,000 construction 

site inspections. Complaints are given 

priority for inspection; however, 

enforcement officers also inspect 

construction sites within their assigned 

area on a routine basis, including nonpermitted construction activities as they 

are encountered in the field. 

3. Enforcement Program 

Clark County relies upon two options 

for handling noncompliant sources: 

issuing a Corrective Action Order (CAO) 

or a Notice of Violation (NOV). In 2001, 

the County issued 1,316 CAOs and as of 

September 2002 has issued 1,775 CAOs. 

In 2001, the County issued 57 NOVs and 

as of September 2002 has issued 133 

NOVs. The penalties assessed for the 

two years combined amount to 

$719,372. CAOs are generally written 

for infractions that are not substantial 

enough to warrant a NOV, allowing 

source owners/operators a first-time 

chance to comply. NOVs are issued for 

more serious violations. Should owners/

operators fail to comply with a CAO, it 

becomes a NOV with associated 

penalties. 

Section 7 provides that the Hearing 

Board Officers be selected by the 

District Board of Health and have the 

authority to levy penalties for alleged 

violations in accordance with section 9 

of Clark County regulations, which 

contains the minimum penalties for 

violations of fugitive dust requirements. 

The minimum penalty for limiting 

visible emissions is $2,000. The 

minimum penalty for not complying 

with other control measure provisions is 

$1,000. Minimum penalties for failing to 

comply with administrative 

requirements related to permit 

conditions is $500 and $250 for other 

administrative requirements. Clark 

County compared these minimum 

penalties for dust violations to those of 

other air regulatory agencies and found 

that they were among the highest in the 

nation. 

4. Public Outreach/Education 

Public outreach and education 

consists of staff training, educating the 

regulated parties, developing good 

working relationships with other 

involved parties such as the cities, and 

making the program more 

understandable. Increased education of 

both inspectors and the regulated 

industry increases compliance. 

Public outreach efforts in which Clark 

County has engaged to improve 

compliance for construction sites 

include publishing and distributing a 

manual that summarizes the section 94 

and section 94 Handbook requirements 

in an easy-to-comprehend format. Also, 

dust control classes and educational 

workshops are regularly offered by the 

DAQM’s Compliance Division. The 

construction site superintendent or 

designated on-site representative and 

water truck and water pull drivers for 

each construction project are required 

per section 94 to have successfully 

completed a Dust Control Class and all 

individuals required to attend must 

successfully complete the Dust Control 

Class at least once every three years. In 

addition, as of 2002, the DAQM has 

conducted a special training effort per 

the section 94 requirement for a 

responsible person to monitor dust (i.e.

‘‘Dust Control Monitor’’) on sites with 

more than 50 acres of disturbed surface. 

To date, two Dust Control Monitor 

classes have been held with over 90 

participants. 

In order to increase awareness among 

vacant lot owners/operators of the 

disturbed vacant lot requirements, Clark 

County prepared and distributed a 

brochure summarizing the section 90 

requirements to over 40,000 vacant 

landowners. 

5. Program Evaluation and Tracking 

Clark County tracks the number of 

inspections, CAOs, NOVs, penalties 

assessed and penalties collected for 

fugitive dust and other sources and 

provides quarterly reports containing 

this information to EPA.

Clark County tracks progress of 

government agencies on their unpaved 

road and paved road SIP commitments 

through a PM–10 SIP Implementation 

Working Group and an Unpaved Road 

Ad Hoc Committee. These groups are

2966 Federal Register / Vol. 68, No. 14 / Wednesday, January 22, 2003 / Proposed Rules 

43Appendix L, pg. L–12 of the Plan. 44 June 28, 2002 letter from the DAQM to EPA 

with attached June 2002 Reasonable Further 

Progress Report.

comprised of DAQM planning and 

compliance staff and staff from the 

County and City public works agencies. 

Unpaved road paving is documented 

using an extranet site and the 

unimproved shoulders program will be 

reviewed through submittal of annual 

reports to the DAQM.43 Also, the Public 

Works Departments in Clark County 

routinely track paved road performance 

and maintenance by checking the 

condition of paved roads in their 

respective jurisdictions.

6. Conclusion 

We propose to find that the Clark 

County PM–10 Plan adequately 

provides for the enforcement of the 

principal measures relied on for 

attainment and that Clark County has 

provided adequate descriptions of its 

enforcement methods as required by our 

regulations. 

We also propose to find that the 

implementing agencies for the Clark 

County Plan have adequate resources for 

implementing their respective 

commitments that are included in the 

submitted Plan and that the Plan 

adequately describes the resources that 

are available or will be available to the 

State and local agencies to carry out the 

Plan, both now and over the next 5 

years. 

I. Demonstration of Attainment and 

Attainment Date Extension 

The Clark County Plan contains an 

analysis that demonstrates attainment of 

the annual PM–10 standard by 

December 31, 2001. Clark County 

predicted that an annual reduction of 

5.66 percent, equivalent to 9,657 tons 

valley-wide and 303 tons for the J.D. 

Smith micro-inventory area, is needed 

to attain the annual 50 μg/m3 standard, 

given an estimated uncontrolled 

concentration of 53 μg/m3. The valleywide rollback modeling predicts annual 

PM–10 concentrations to be 46.2 μg/m3

in 2001. The corresponding 

microinventory projection for J.D. 

Smith, the exceeding site, is 48.5 μg/m3, 

also less than 50 μg/m3. Together, these 

demonstrate attainment of the annual 

PM–10 standard by 2001. We propose to 

find this demonstration adequate. The 

adequacy of the demonstration is further 

supported by information provided by 

the DAQM to EPA 44 indicating that the 

three-year annual average (1999–2001) 

of the microscale sites is below the 50 

μg/m3 standard.

Clark County has requested an 

extension of the attainment date for the 

24-hour 150 μg/m3 PM–10 standard. 

Section 188(e) of the Act allows us to 

extend the attainment date for a serious 

area for up to five years beyond 2001 if 

attainment by 2001 is impracticable. 

However, before we may grant an 

extension of the attainment date, the 

State must first: 

1. Apply to us for an extension of the 

PM–10 attainment date beyond 2001, 

2. Demonstrate that attainment by 

2001 is impracticable, 

3. Have complied with all 

requirements and commitments 

applying to the area in its 

implementation plan, 

4. Demonstrate to our satisfaction that 

its serious area plan includes the most 

stringent measures that are included in 

the implementation plan of any state 

and/or are achieved in practice in any 

state and are feasible for the area, and 

5. Submit a demonstration of 

attainment by the most expeditious 

alternative date practicable. 

We evaluate the Clark County serious 

area plan’s compliance with each of 

these requirements below. 

1. Apply for an Extension 

The documentation supporting Clark 

County’s extension request is found in 

Chapter 7 of the Plan. This extension 

request is an integral part of the Clark 

County Plan and was subject to public 

hearing along with the rest of the plan, 

including the demonstration that the 

area will attain the 24-hour standard by 

the earliest alternative date practicable. 

2. Demonstrate the Impracticability of 

Attainment by December 31, 2001 

Clark County’s determination that 

demonstrating attainment of the 24-hour 

standard by 2001 is impracticable is 

primarily based upon the need for 

increased enforcement staffing, which 

could not be completed until the end of 

2001. Clark County conservatively 

assumes that the rule effectiveness of its 

regulations in 2001 is half of what it 

will need to be in 2006 to demonstrate 

attainment of the 24-hour standard. 

Also, with respect to the unpaved 

roads schedule, Clark County indicates 

that the maximum benefit that will be 

realized at the end of 2003 from the 

appropriated CMAQ funding cannot 

practicably be achieved earlier due to 

funding limitations each year. 

Notwithstanding, we note from the 

DAQM’s June 2002 RFP Report that the 

responsible entities have exceeded the 

Section 91 required 33 percent paving of 

roads subject to the rule by 2001 and 

reported paving 86 percent, or a total of 

55 of the 64 mile inventory of unpaved 

roads with 150 vehicle trips per day. 

With respect to improvements to 

paved road shoulders, Clark County has 

committed to stabilize 33 miles of paved 

road shoulders by the end of 2003 using 

appropriated CMAQ funds and all 

shoulders by 2006. The remaining 

shoulders have a later implementation 

date given that new CMAQ funds will 

need to be appropriated and first 

committed towards the carbon 

monoxide transportation demand 

management program. Thus, earlier 

implementation would be 

impracticable. 

The modeled valley-wide 24-hour 

value for 2001 is 209 μg/m3. Although 

this is a significant reduction from the 

projected design day value of 281 μg/

m3, it still falls far short of the 150 μg/

m3 standard.

Thus, we propose to find that Clark 

County has demonstrated the 

impracticability of meeting the 24-hour 

standard by 2001. 

3. Complied With Commitments and 

Requirements in the SIP 

All measures upon which Clark 

County is relying to meet the applicable 

CAA requirements for a Serious Area 

PM–10 plan are included or referenced 

in the current June 2001 Plan, as 

amended by Clark County in November 

2002. 

4. Include the Most Stringent Measures 

Clark County identified candidate 

MSM in the context of its analysis to 

identify potential BACM, generally 

finding that control measures being 

implemented in other PM–10 serious 

nonattainment areas in the western U.S. 

were the most stringent controls 

implemented by others for the types of 

fugitive PM–10 sources requiring 

control in the Las Vegas Valley. 

In the Clark County Plan, after a 

comprehensive list of candidate MSM 

was developed, each measure was 

screened against the corresponding 

Clark County measure to identify those 

with more restrictive emission 

limitations, more extensive lists of 

affected sources, fewer exemptions, 

and/or one or more substantive 

regulatory provisions not found in the 

Clark County measure. Clark County 

includes a measure-by-measure MSM 

comparison in Chapter 6 of the Plan. 

Based on our analysis of the Clark 

County Plan, we propose to find that it 

demonstrates to our satisfaction 

inclusion of the most stringent measures 

that are included in the implementation 

plan of any State, or are achieved in 

practice in any State, and can be 

feasibly implemented in the Clark 

County area.

Federal Register / Vol. 68, No. 14 / Wednesday, January 22, 2003 / Proposed Rules 2967

45 Guideline On Air Quality Models, 2001, 

sections 7.2.1 and 7.2.2.

46Emission reductions for section 92 controls 

were only specifically calculated for the two 

microscale areas that included unpaved parking as 

opposed to a valley-wide basis. These microscale 

areas play a role in the 24-hour but not annual 

attainment demonstration. Clark County did not 

prepare a separate valley-wide inventory for 

unpaved parking lots apart from the disturbed 

vacant land inventory. Thus, reductions attributable 

to the section 92 controls are only implicitly 

assumed, for purposes of the annual attainment 

demonstration, within the larger valley-wide 

emission reductions anticipated from disturbed 

vacant land.

5. Demonstrate Expeditious Attainment 

For the reasons discussed below, we 

propose to find that the Clark County 

Plan demonstrates attainment by the 

earliest date practicable after December 

31, 2001 as required by CAA section 

189(b)(1)(A)(ii). We also propose to find 

that: The attainment demonstration 

relies on control measures that either 

are approved or have been proposed for 

approval and meet our SIP 

enforceability criteria; the emissions 

estimates credited to these measures in 

the attainment demonstration are 

reasonable; and the measures are being 

implemented on a schedule that is as 

expeditious as practicable and will 

result in attainment by the earliest 

practicable date. 

a. Air Quality Modeling 

The attainment demonstration for the 

24-hour standard in the Clark County 

Plan is divided into two parts, a 

microscale analysis and a regional 

analysis. The microscale part evaluates 

24-hour exceedences at five monitoring 

sites in the Las Vegas. The regional part 

evaluates 24-hour levels throughout the 

rest of the Clark County nonattainment 

area. 

Clark County relies upon an 

emissions ‘‘rollback’’ model for the 

attainment demonstrations. EPA’s 

guidelines 45 allow the need for case-bycase approaches in circumstances when 

recommended dispersion models are 

not available or applicable and where 

area sources are the predominant 

component of PM–10. To predict future 

concentration, the current concentration 

is reduced or ‘‘rolled back’’ by the same 

fractional amount that emissions are 

reduced. In recognition of the special 

characteristics of fugitive dustdominated areas, we believe an 

attainment demonstration based on 

proportional rollback of one or more 

microinventories is a reasonable 

approach and is consistent with EPA 

guidance, as long as the microinventory 

areas are representative of worst case 

conditions, and the resulting emission 

controls are applied throughout the 

area.

We have evaluated the five 

microinventory areas mentioned 

previously in this document and find 

that they contain varying source 

category mixes and span a range of 

conditions that occur in the Las Vegas 

Valley. By showing that the chosen 

microinventory areas are representative 

of conditions leading to PM–10 NAAQS 

exceedences, and by then applying the 

controls shown to be needed in these 

microareas to the entire nonattainment 

area, Clark County has followed an 

acceptable procedure for demonstrating 

attainment. 

b. Control Measures Relied on for 

Attainment 

For demonstrating attainment of the 

annual and 24-hour PM–10 standards, 

the Clark County Plan relies on 

reductions in directly-emitted PM–10 

from the following measures: Section 90 

controls for disturbed vacant land, 

section 92 controls for unpaved parking 

lots,46 section 94 (including Handbook) 

controls for construction sites, section 

91 and government agency SIP 

commitment controls for unpaved 

roads, and section 93 and government 

agency SIP commitment controls for 

unpaved road shoulders (within the 

paved road dust category).

For the 24-hour attainment 

demonstration, Clark County models 

controlled valley-wide future 

concentrations for the years 2001 and 

2006 as well as controlled 2006 

concentrations at each of the five 

microscale sites. We have evaluated the 

emissions reductions credited to each 

measure in the attainment 

demonstrations to ensure they are 

reasonable. Three factors considered 

include: 

1. Emissions reductions from controls 

applied (e.g. percent reduction achieved 

through paving or chemical 

stabilization); 

2. Rule penetration (i.e. percentage of 

sources within the total source category 

that the rule or measure will impact); 

and 

3. Rule effectiveness (i.e. the expected 

rate of compliance with a rule or 

measure).

We find that the emission reduction 

estimates for each source category are 

consistent with available research on 

the applicable control methods, rule 

penetration estimates are reasonable 

based on emissions inventory data, and 

rule effectiveness estimates are 

reasonable given the schedule for 

adoption of measures and other factors. 

Emissions reductions credited based on 

these estimates are appropriately 

applied in the attainment 

demonstrations. For more information 

on the quantification of emission 

reductions, we refer to the TSD 

associated with this rulemaking. 

We are also proposing that the 

measures relied on for attainment are 

being expeditiously implemented. 

Section 90, 91, 92, 93 and 94 

requirements all applied well before 

adoption of the Clark County Plan in 

June 2001. While Clark County has 

revised the original SIP commitment 

deadline for adopting certain revisions 

to its fugitive dust regulations to March 

31, 2003, these revisions provide 

incremental reductions above an 

already-adopted baseline that should 

achieve substantial immediate 

reductions. Therefore, we believe the 

extension is reasonable and does not 

impact our finding that the Plan 

provides for expeditious 

implementation of measures. Finally, 

Clark County’s SIP commitment for 

hiring additional staff to implement and 

enforce fugitive dust controls was 

established with an expeditious 

timeframe for all positions to be filled 

by the end of 2001. Clark County has 

not only met, but exceeded this 

commitment. 

6. Other Factors That EPA May Consider 

CAA section 188(e) lists five 

additional factors that we may consider 

in deciding whether to grant an 

extension and the length of that 

extension. These include: (1) The nature 

and extent of the nonattainment 

problem; (2) the types and numbers of 

sources or other emitting activities in 

the area (including the influence of 

uncontrollable natural sources and 

international transport); (3) the 

population exposed to concentrations in 

excess of the standard; (4) the presence 

and concentration of potentially toxic 

substances in the mix of particulate 

emissions in the area; and (5) the 

technological and economic feasibility 

of various control measures. 

In evaluating these factors, we have 

focused on the nature and extent of the 

nonattainment area problem, the types 

of sources contributing to the problem, 

and the ability of the County to control 

these sources. Fugitive dust sources 

dominate the emissions inventory in the 

Clark County PM–10 nonattainment 

area. Controls for these sources are well 

known (paving, wetting surfaces, etc.) 

and have been adopted; however, the 

number of sources and nature of sources 

make education, outreach and enhanced 

enforcement necessary to assure full 

compliance with those controls. In 

addition, costs for paving roads and 

stabilizing shoulders necessary to

2968 Federal Register / Vol. 68, No. 14 / Wednesday, January 22, 2003 / Proposed Rules 

reduce PM–10 emissions are high and 

funds are only available over a number 

of years. These factors generally support 

a longer time frame for attainment. 

7. Conclusion on Extension Request 

Based on our review of the Clark 

County Plan and our proposed 

determination that it meets the 

requirements necessary for granting an 

extension of the attainment date under 

CAA section 188(e), we are proposing to 

grant a five-year extension of the 

attainment date for the 24-hour PM–10 

standard in the Clark County PM–10 

serious nonattainment area from 

December 31, 2001 to December 31, 

2006. 

J. Reasonable Further Progress and 

Quantitative Milestones 

CAA section 172(c)(2) requires 

nonattainment plans to provide for 

reasonable further progress (RFP). 

Section 171(1) of the Act defines RFP as 

‘‘such annual incremental reductions in 

emissions of the relevant air pollutant as 

are required by this part (part D of title 

I) or may reasonable be required by the 

Administrator for the purpose of 

ensuring attainment of the applicable 

national ambient air quality standard by 

the applicable date.’’

CAA section 189(c) also requires PM–

10 plans demonstrating attainment to 

contain quantitative milestones which 

are to be achieved every 3 years until 

the area is redesignated attainment and 

which demonstrate RFP. These 

quantitative milestones should consist 

of elements that allow progress to be 

quantified or measured. Addendum at 

42016. 

Clark County identified milestone 

achievement dates of 2003 and 2006 

with respect tp the 24-hour standard. 

The milestones have been addressed by 

quantifying emission reductions which 

result from the implementation of the 

committed control measures after 

predicted growth has occurred. 

Emissions by 2003 are projected to be 

reduced substantially to 276.48 tons per 

day, with 77.23 additional tons per day 

reductions occurring between 2003 and 

2006, resulting in 199.25 tons per day. 

Clark County indicates that total 

emissions under 210.70 tons per day 

should result in attainment of the 24-

hour standard. RFP Reports are due at 

the end of 2003 and 2006, which 

correspond with Clark County’s 

milestone achievement dates. 

The milestones for the 24-hour 

standard are based on reasonable 

assumptions that are consistent with the 

implementation schedules for the 

measures in the plan and with the RFP 

demonstrations. For these reasons, we 

propose to find that the Plan meets the 

quantitative milestone requirement in 

CAA section 189(c)(1). 

K. Contingency Measures 

Section 172(c)(9) of the Clean Air Act 

requires that implementation plans 

provide for the implementation of 

specific measures to be undertaken if 

the area fails to make RFP or attain by 

its attainment deadline. These 

contingency measures are to take effect 

without further action by the State or 

the Administrator. The Act does not 

specify how many contingency 

measures are necessary nor does it 

specify the level of emission reductions 

they must produce.

The purpose of contingency measures 

is to ensure that additional emission 

reductions beyond those relied on in the 

attainment and RFP demonstrations are 

available if there is a failure to make 

RFP or attain by the applicable 

attainment date. These additional 

emission reductions will assure 

continued progress towards attainment 

while the SIP is being revised to fully 

correct the failure. To ensure this 

continued progress, we recommend that 

contingency measures provide emission 

reductions equivalent of one year’s 

average increment of RFP. Addendum at 

42016. 

The following contingency measures 

were adopted by Clark County Health 

District Board of Health Resolution #03–

00 on July 27, 2000. 

1. Reduce the threshold for sitespecific dust mitigation plan 

requirements for construction activities 

from ten acres to five acres; 

2. Require paving/stabilization of all 

unpaved roads with ≥ 100 average daily 

vehicle trips; 

3. Provide for at least two additional 

field enforcement officers above and 

beyond those staff increases committed 

to in the State Implementation Plan; 

4. Increase minimum penalties for 

violations of Air Quality Regulations for 

fugitive dust; and 

5. Reduce the size threshold for 

requiring a dust control monitor 

(coordinator) at construction sites. 

Clark County describes that the entire 

set of contingency measures will be 

automatically implemented if Clark 

County fails to meet the projected 2003 

emissions reduction milestone. We note 

that Clark County has already 

implemented Contingency Measure 3 

for field enforcement officer staff 

increases above and beyond the staff 

increases committed to in the Plan. 

Clark County estimates the emissions 

reduction benefit from the contingency 

measures to be 1,373 tons per year in 

total. This annual reduction exceeds the 

annual average increment of RFP. 

The contingency measures identified 

in the Plan have been adopted but are 

not credited in the attainment, RFP or 

milestone demonstrations for the 24-

hour standard and are not necessary to 

demonstrate expeditious attainment of 

the standard. 

Therefore, we propose to find that the 

Plan provides for the implementation of 

contingency measures for the 24-hour 

standard as required by CAA section 

172(c)(9). This proposal is based on our 

analysis that these contingency 

measures comply with applicable CAA 

requirements and EPA policy. 

L. Administrative Requirements 

Under Executive Order 12866 (58 FR 

51735, October 4, 1993), this proposed 

action is not a ‘‘significant regulatory 

action’’ and therefore is not subject to 

review by the Office of Management and 

Budget. For this reason, this proposed 

action is also not subject to Executive 

Order 32111, ‘‘Actions Concerning 

Regulations That Significantly Affect 

Energy Supply, Distribution, or Use’’ (66 

FR 28355, May 22, 2001). This proposed 

action merely approves state law as 

meeting federal requirements and 

imposes no additional requirements 

beyond those imposed by state law. 

Accordingly, the Administrator certifies 

that this proposed rule will not have a 

significant economic impact on a 

substantial number of small entities 

under the Regulatory Flexibility Act (5 

U.S.C. 601 et seq.). Because this rule 

proposes to approve pre-existing 

requirements under state law and does 

not impose any additional enforceable 

duty beyond that required by state law, 

it does not contain any unfunded 

mandate or significantly or uniquely 

affect small governments, as described 

in the Unfunded Mandates Reform Act 

of 1995 (Pub. L. 104–4). This rule also 

does not have a substantial direct effect 

on one or more Indian tribes, on the 

relationship between the Federal 

Government and Indian tribes, or on the 

distribution of power and 

responsibilities between the Federal 

Government and Indian tribes, as 

specified by Executive Order 13175 (65 

FR 67249, November 9, 2000), nor will 

it have substantial direct effects on the 

States, on the relationship between the 

national government and the States, or 

on the distribution of power and 

responsibilities among the various 

levels of government, as specified in 

Executive Order 13132 (64 FR 43255, 

August 10, 1999), because it merely 

approves a state rule implementing a 

federal standard, and does not alter the 

relationship or the distribution of power

Federal Register / Vol. 68, No. 14 / Wednesday, January 22, 2003 / Proposed Rules 2969

and responsibilities established in the 

Clean Air Act. This proposed rule also 

is not subject to Executive Order 13045 

(62 FR 19885, April 23, 1997), because 

it is not economically significant. 

In reviewing SIP submissions, EPA’s 

role is to approve state choices, 

provided that they meet the criteria of 

the Clean Air Act. In this context, in the 

absence of a prior existing requirement 

for the State to use voluntary consensus 

standards (VCS), EPA has no authority 

to disapprove a SIP submission for 

failure to use VCS. It would thus be 

inconsistent with applicable law for 

EPA, when it reviews a SIP submission, 

to use VCS in place of a SIP submission 

that otherwise satisfies the provisions of 

the Clean Air Act. Thus, the 

requirements of section 12(d) of the 

National Technology Transfer and 

Advancement Act of 1995 (15 U.S.C. 

272 note) do not apply. This proposed 

rule does not impose an information 

collection burden under the provisions 

of the Paperwork Reduction Act of 1995 

(44 U.S.C. 3501 et seq.).

List of Subjects in 40 CFR Part 52 

Environmental protection, Air 

pollution control, Intergovernmental 

relations, Particulate matter, Reporting 

and recordkeeping requirements.

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

Dated: January 9, 2003 

Wayne Nastri, 

Regional Administrator, Region IX.

[FR Doc. 03–1145 Filed 1–21–03; 8:45 am] 

BILLING CODE 6560–50–P

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 52 

[OH118–1b; FRL–7428–4] 

Approval and Promulgation of 

Implementation Plans; Ohio

AGENCY: Environmental Protection 

Agency (EPA).

ACTION: Proposed rule.

SUMMARY: The EPA is proposing to 

approve, as a revision to the Ohio State 

Implementation Plan (SIP), the 

remaining portions of the Ohio 

Environmental Protection Agency’s 

(OEPA) regulations for Prevention of 

Significant Deterioration (PSD) 

provisions for attainment areas. EPA 

had previously conditionally approved 

Ohio’s prior SIP submission on October 

10, 2001. Today’s proposed final 

approval of changes in the plan 

correcting minor deficiencies cited in 

EPA’s original conditional approval, is 

based on Ohio’s July 18, 2002, 

submission of revisions to the Ohio 

Administrative Code (OAC). In its July 

2002 submittal, Ohio also made 

additional revisions to the OAC that 

were not addressed in EPA’s October 10, 

2001 conditional approval. 

Recently, EPA announced new 

regulations regarding changes to the 

preconstruction permit program under 

EPA’s efforts regarding ‘‘New Source 

Review Reform.’’ Today’s approval of 

Ohio’s SIP submission does not address 

EPA’s new rules but is limited to 

portions of Ohio’s preconstruction 

permit program under the existing rules. 

EPA is taking no position today on 

whether Ohio will need to make 

changes to its SIP to meet any 

requirements that EPA may promulgate 

as part of New Source Review Reform. 

In the ‘‘Rules and Regulations’’

section of this Federal Register, EPA is 

approving the State’s request as a direct 

final rule without prior proposal 

because EPA views this action as 

noncontroversial and anticipates no 

adverse comments. The rationale for 

approval is set forth in the direct final 

rule. If EPA receives no written adverse 

comments, EPA will take no further 

action on this proposed rule. If EPA 

receives written adverse comment, we 

will publish a timely withdrawal of the 

direct final rule in the Federal Register

and inform the public that the rule will 

not take effect. In that event, EPA will 

address all relevant public comments in 

a subsequent final rule based on this 

proposed rule. In either event, EPA will 

not institute a second comment period 

on this action. Any parties interested in 

commenting must do so at this time.

DATES: Comments on this action must be 

received by February 21, 2003.

ADDRESSES: Copies of the documents 

relevant to this action are available for 

inspection during normal business 

hours at the following location: Permits 

and Grants Section, Air Programs 

Branch, (AR–18J), U.S. Environmental 

Protection Agency, Region 5, 77 West 

Jackson Boulevard, Chicago, Illinois 

60604. 

Please contact Genevieve Damico at 

(312) 353–4761 before visiting the 

Region 5 office. 

Written comments should be sent to: 

Pamela Blakley, Chief, Permits and 

Grants Section, Air Programs Branch, 

(AR–18J), U.S. Environmental 

Protection Agency, Region 5, 77 West 

Jackson Boulevard, Chicago, Illinois 

60604.

FOR FURTHER INFORMATION CONTACT:

Genevieve Damico, Environmental 

Engineer, Permits and Grants Section, 

Air Programs Branch, (AR–18J), U.S. 

Environmental Protection Agency, 

Region 5, 77 West Jackson Boulevard, 

Chicago, Illinois 60604, (312) 353–4761.

SUPPLEMENTARY INFORMATION:

Throughout this document whenever 

‘‘we,’’ ‘‘us,’’ or ‘‘our’’ are used we mean 

the EPA.

I. What action is EPA taking today? 

II. Where can I find more information about 

this proposal and corresponding direct 

final rule?

I. What Action Is EPA Taking Today? 

The EPA is proposing to approve, as 

a revision to the SIP, the remaining 

portions of the Ohio Environmental 

Protection Agency’s (OEPA) PSD 

provisions for attainment areas. EPA 

had previously conditionally approved 

Ohio’s prior SIP submission on October 

10, 2001 (66 FR 51570). Today’s 

proposed final approval of EPA’s 

original conditional approval is based 

on Ohio’s July 18, 2002, submission of 

the revisions to the OAC. In its July 

2002 submittal, Ohio also made 

additional revisions to OAC 3745–31–

01, –02, –03, –05, and –07 that were not 

addressed in EPA’s October 10, 2001 

conditional approval. 

Recently, EPA announced new 

regulations regarding changes to the 

preconstruction permit program under 

EPA’s efforts regarding ‘‘New Source 

Review Reform’’. See http://

www.epa.gov/nsr/. Today’s approval of 

Ohio’s SIP submission does not address 

EPA’s new rules but is limited to 

portions of Ohio’s preconstruction 

permit program under the existing rules. 

EPA is taking no position today on 

whether Ohio will need to make 

changes to its SIP to meet any 

requirements that EPA may promulgate 

as part of New Source Review Reform. 

II. Where Can I Find More Information 

About This Proposal and 

Corresponding Direct Final Rule? 

For additional information see the 

direct final rule published in the rules 

and regulations section of this Federal 

Register.

Authority: 42 U.S.C. 4201 et seq.

Dated: December 13, 2002. 

Bharat Mathur, 

Acting Regional Administrator, Region 5.

[FR Doc. 03–1236 Filed 1–21–03; 8:45 am] 

BILLING CODE 6560–50–P