ENVIRONMENTAL PROTECTION AGENCY 

40 CFR Part 81 

[EPA-R09-OAR-2010-0590; FRL-] 

Determination of Attainment for PM10 for the Las Vegas Valley 

Nonattainment Area, Nevada

AGENCY: Environmental Protection Agency (EPA). 

ACTION: Direct final rule. 

SUMMARY: EPA has determined that the Las Vegas Valley 

nonattainment area in Nevada attained the National Ambient Air 

Quality Standard (NAAQS) for particulate matter with an 

aerodynamic diameter of less than or equal to a nominal ten 

micrometers (PM10) by the applicable attainment date (December 

31, 2006), and that the Las Vegas Valley nonattainment area is 

currently attaining the standard. 

DATES: This action is effective on [Federal Register: Insert 

date 60 days after the publication date] without further notice, 

unless EPA receives adverse comment by [Federal Register: Insert 

date 30 days after the publication date]. If EPA receives 

adverse comment, we will publish a timely withdrawal in the 

Federal Register informing the public that the rule will not 

take effect. 

ADDRESSES: Submit comments, identified by docket number EPAR09-OAR-2010-0590, by one of the following methods:
2 

1. Federal eRulemaking Portal: www.regulations.gov. Follow 

the on-line instructions. 

2. E-mail: tax.wienke@epa.gov. 

3. Mail or deliver: Wienke Tax, Air Planning Office, EPA 

Region IX, 75 Hawthorne Street, San Francisco, CA 94105-

3901. 

Instructions: All comments will be included in the public 

docket without change and may be made available online at 

www.regulations.gov, including any personal information 

provided, unless the comment includes Confidential Business 

Information (CBI) or other information whose disclosure is 

restricted by statute. Information that you consider CBI or 

otherwise protected should be clearly identified as such and 

should not be submitted through www.regulations.gov or e-mail. 

www.regulations.gov is an “anonymous access” system, and EPA 

will not know your identity or contact information unless you 

provide it in the body of your comment. If you send an e-mail 

directly to EPA, your e-mail address will be automatically 

captured and included as part of the public comment. If you 

submit an electronic comment, EPA recommends that you include 

your name and other contact information in the body of your 

comment and with any disk or CD-ROM you submit. If EPA cannot 

read your comment due to technical difficulties and cannot 

contact you for clarification, EPA may not be able to consider 
3 

your comment. Electronic files should avoid the use of special 

characters, any form of encryption, and be free of any defects 

or viruses. 

Docket: The index to the docket for this action is available 

electronically at www.regulations.gov and in hard copy at EPA 

Region IX, 75 Hawthorne Street, San Francisco, California. While 

all documents in the docket are listed in the index, some 

information may be publicly available only at the hard copy 

location (e.g., copyrighted material), and some may not be 

publicly available in either location (e.g., CBI). To inspect 

the hard copy materials, please schedule an appointment during 

normal business hours with the contact listed in the FOR FURTHER 

INFORMATION CONTACT section. 

FOR FURTHER INFORMATION CONTACT: Wienke Tax at telephone 

number: (415) 947-4192, e-mail address: tax.wienke@epa.gov, or 

the above EPA, Region IX address. 

SUPPLEMENTARY INFORMATION: Throughout this document, wherever 

“we”, “us” or “our” are used, we mean EPA. Information is 

organized as follows: 

Table of Contents 

I. Background 

A. PM10 NAAQS 

B. Designation and Classification of PM10 Nonattainment Areas 

C. How does EPA make attainment determinations? 
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D. What is the attainment date for the Las Vegas Valley PM10

nonattainment area? 

E. What PM10 planning has occurred for the Las Vegas Valley 

PM10 nonattainment area? 

II. EPA's Analysis 

A. What does the air quality data show as of the December 31, 

2006 attainment date? 

B. Does more recent air quality data also show attainment? 

III. EPA’s Final Action 

IV. Statutory and Executive Order Reviews 

I. Background 

A. PM10 NAAQS 

The NAAQS are levels for certain ambient air pollutants set 

by EPA to protect public health and welfare. PM10, or particulate 

matter with an aerodynamic diameter less than or equal to a 

nominal 10 micrometers, is among the ambient air pollutants for 

which EPA has established health-based standards. On July 1, 

1987 (52 FR 24634), EPA promulgated two primary standards for 

PM10: a 24-hour standard of 150 micrograms per cubic meter 

(μg/m3) and an annual PM10 standard of 50 μg/m3. EPA also 

promulgated secondary PM10 standards that were identical to the 

primary standards. 

Effective December 18, 2006, EPA revoked the annual PM10

standard but retained the 24-hour PM10 standard. 71 FR 61144 
5 

(October 17, 2006). The 24-hour PM10 standard is attained when 

the expected number of days per calendar year with a 24-hour 

concentration in excess of the standard (referred to herein as 

“exceedance”), as determined in accordance with 40 CFR part 50, 

appendix K, is equal to or less than one.1 40 CFR 50.6 and 40 CFR 

part 50, appendix K. 

B. Designation and Classification of PM10 Nonattainment 

Areas 

Areas meeting the requirements of section 107(d)(4)(B) of 

the Clean Air Act (CAA or the Act) were designated nonattainment 

for PM10 by operation of law and classified “moderate” upon 

enactment of the 1990 Clean Air Act Amendments. See generally 42 

U.S.C. 7407(d)(4)(B). These areas included all former Group I 

PM10 planning areas identified in 52 FR 29383 (August 7, 1987), 

as further clarified in 55 FR 45799 (October 31, 1990), and any 

other areas violating the NAAQS for PM10 prior to January 1, 

1989. A Federal Register notice announcing the areas designated 

nonattainment for PM10 upon enactment of the 1990 Amendments, 

 

1

 An exceedance is defined as a daily value that is above the 

level of the 24-hour standard (150 μg/m3

) after rounding to the 

nearest 10 μg/m3

 (i.e., values ending in 5 or greater are to be 

rounded up). Thus, a recorded value of 154 μg/m3 would not be an 

exceedance since it would be rounded to 150 μg/m3

 whereas a 

recorded value of 155 μg/m3

 would be an exceedance since it would 

be rounded to 160 μg/m3

. See 40 CFR part 50, appendix K, section 

1.0. 
6 

known as “initial” PM10 nonattainment areas, was published on 

March 15, 1991 (56 FR 11101) and a subsequent Federal Register

document correcting the description of some of these areas was 

published on August 8, 1991 (56 FR 37654). The Las Vegas Valley2

was one of these initial moderate PM10 nonattainment areas. 

All initial moderate PM10 nonattainment areas had the same 

applicable attainment date of December 31, 1994. States 

containing initial moderate PM10 nonattainment areas were 

required to develop and submit to EPA by November 15, 1991, a 

state implementation plan (SIP) revision providing for 

implementation of reasonably available control measures (RACM) 

for the control of PM10, and either a demonstration that the plan 

would provide for attainment by the applicable attainment date 

(December 31, 1994) or a demonstration that attainment by such 

date was impracticable. See CAA section 189(a). 

 

2

 Specifically, the Las Vegas Valley PM10 nonattainment area is 

defined by reference to State hydrographic area #212. See 40 CFR 

81.329. The Las Vegas Valley encompasses roughly 1,500 square 

miles within Clark County and includes the cities of Las Vegas, 

North Las Vegas, and Henderson. Roughly two million people 

reside in Clark County, mostly within Las Vegas Valley. NDEP is 

the state agency under state law that is responsible for SIP 

matters for the State of Nevada. Within Clark County, the Clark 

County Board of Commissioners, acting through the Department of 

Air Quality and Environmental Management (DAQEM), is empowered 

under state law to develop air quality plans and to regulate 

stationary sources within the county with the exception of 

certain types of power plants, which lie exclusively within the 

jurisdiction of NDEP. 
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A moderate PM10 area could subsequently be reclassified as 

“serious” either before the applicable moderate area attainment 

date if EPA determines the area cannot “practicably” attain the 

PM10 NAAQS by this attainment date, or following the passage of 

the applicable moderate area attainment date if EPA determines 

that the area has failed to attain the standard. Effective 

February 8, 1993, EPA determined that Las Vegas Valley could not 

“practicably” attain the PM10 NAAQS by December 31, 1994 (i.e., 

the applicable attainment date for initial moderate PM10

nonattainment areas), and reclassified the area as “serious.” 

See 58 FR 3334 (January 8, 1993). Reclassification of Las Vegas 

Valley to “serious” triggered deadlines for additional SIP 

revisions and established a new applicable attainment date of 

(no later than) December 31, 2001. See CAA section 188(c)(2). 

Section 188(e) of the Act authorizes EPA to extend the 

applicable attainment date for serious PM10 nonattainment areas 

under certain circumstances. In 2004, EPA approved the PM10

attainment plan for Las Vegas Valley and granted the State of 

Nevada’s request to extend the applicable attainment date from 

December 31, 2001 to December 31, 2006. See 69 FR 32273 (June 9, 

2004). 

C. How does EPA make attainment determinations? 

Section 188(b)(2) of the Act requires EPA to determine 

within six months of the applicable attainment date whether, 
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based on air quality data, PM10 nonattainment areas attained the 

PM10 NAAQS by that date. Generally, EPA determines whether an 

area’s air quality is meeting the PM10 NAAQS based upon complete 

(minimum of 75 percent of scheduled PM10 samples recorded), 

quality-assured data gathered at established state and local air 

monitoring stations (SLAMS) and national air monitoring stations 

(NAMS) in the nonattainment area and entered into the EPA Air 

Quality System (AQS) database. Data from air monitors operated 

by State/local/tribal agencies in compliance with EPA monitoring 

requirements must be submitted to AQS. EPA relies primarily on 

data in AQS when determining the attainment status of an area. 

See 40 CFR 50.6; 40 CFR part 50, appendix J; 40 CFR part 53; 40 

CFR part 58, appendix A. EPA will also consider air quality data 

from other air monitoring stations in the nonattainment area 

provided that the stations meet the Federal monitoring 

requirements for SLAMS, including the quality assurance and 

quality control criteria in 40 CFR part 58, appendix A. 40 CFR 

58.14 (2006) and 58.20 (2007);3 71 FR 61236, 61242 (October 17, 

2006). All valid data are reviewed to determine the area's air 

quality status in accordance with 40 CFR part 50, appendix K. 

 

3

 EPA promulgated amendments to the ambient air monitoring 

regulations in 40 CFR parts 53 and 58 on October 17, 2006. See 

71 FR 61236. The requirements for Special Purpose Monitors were 

revised and moved from 40 CFR 58.14 to 40 CFR 58.20. 
9 

Attainment of the 24-hour PM10 standard is determined by 

calculating the expected number of exceedances of the standard 

in a year. The 24-hour standard is attained when the expected 

number of exceedances averaged over a three-year period is less 

than or equal to one at each monitoring site within the 

nonattainment area. Generally, three consecutive years of air 

quality data are required to show attainment of the 24-hour PM10

standard. See 40 CFR part 50 and appendix K.4

D. What is the attainment date for the Las Vegas Valley PM10 

nonattainment area? 

As noted above, the original attainment date for the Las 

Vegas Valley PM10 nonattainment area was December 31, 1994, but 

was later extended, first to December 31, 2001, and later, to 

December 31, 2006. See 58 FR 3334 (January 8, 1993) and 69 FR 

32273 (June 9, 2004). 

E. What PM10 planning has occurred for the Las Vegas Valley PM10

nonattainment area? 

After Las Vegas Valley was designated nonattainment for 

PM10, Clark County and NDEP began in the early 1990s to prepare 

the technical elements needed to bring the area into attainment 

and meet the planning requirements of title I of the CAA. NDEP 

submitted a moderate area PM10 plan for the Las Vegas Valley on 

 

4

 Because the annual PM10 standard was revoked effective 

December 18, 2006, see 71 FR 61144 (October 17, 2006), this 

document discusses only attainment of the 24-hour PM10 standard. 
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December 6, 1991. Based on this submittal, EPA determined on 

January 8, 1993, that the Las Vegas Valley could not practicably 

attain the PM10 NAAQS by the applicable attainment deadline for 

moderate areas (December 31, 1994, per section 188(c)(1) of the 

Act),and reclassified the Las Vegas Valley as serious (58 FR 

3334). 

In response to the area’s reclassification as a “serious” 

PM10 nonattainment area, Clark County prepared and, and NDEP 

submitted, a serious area PM10 plan in 1997 that EPA subsequently 

proposed to disapprove, along with the previously submitted 

plan. See 65 FR 37324 (June 14, 2000). However, NDEP submitted a 

revised serious area PM10 plan in July 2001, which EPA later 

approved. 69 FR 32273 (June 9, 2004). Among the various serious 

area SIP elements approved by EPA in 2004 are the best available 

control measures (BACM) demonstration under CAA section 

189(b)(1)(B), the most stringent measures (MSM) demonstration 

under CAA section 188(e), and various Clark County air pollution 

control rules regulating such fugitive dust sources as open 

areas, unpaved roads, and construction activities. 

II. EPA's Analysis

A. What does the air quality data show as of the December 31, 

2006 attainment date? 

Clark County DAQEM is responsible for monitoring ambient 

air quality within Clark County. DAQEM submits monitoring 
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network plan reports to EPA on an annual basis. These reports 

discuss the status of the air monitoring network, as required 

under 40 CFR part 58. Beginning in 2007, EPA reviews these 

annual plans for compliance with the applicable reporting 

requirements in 40 CFR 58.10. With respect to PM10, we have found 

DAQEM’s annual network plans to meet the applicable requirements 

under 40 CFR part 58. See EPA letters to DAQEM concerning 

DAQEM’s annual network plan reports for years 2007, 2008, and 

2009. Furthermore, we concluded in our Technical System Audit 

Report (February 2010) that Clark County DAQEM’s ambient air 

monitoring network currently meets or exceeds the requirements 

for the minimum number of monitoring sites designated as SLAMS 

for all of the criteria pollutants, and that all of the 

monitoring sites are properly located with respect to monitoring 

objectives, spatial scales and other site criteria. 

Clark County DAQEM currently operates nine PM10 SLAMS 

monitoring sites within Las Vegas Valley: Craig Road (North Las 

Vegas), Green Valley (Henderson), J.D. Smith School (North Las 

Vegas), Joe Neal (northwest Las Vegas), Lone Mountain (northwest 

Las Vegas), Orr School (central-southeast Las Vegas), Paul Meyer 

Park (southwest Las Vegas), Palo Verde School (west Las Vegas), 

Sunrise Acres School (central Las Vegas), and Walter Johnson 

(west Las Vegas). All nine sites monitor PM10 concentrations on a 

continuous basis using Beta Attenuation Monitors (BAMs). See 
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Clark County DAQEM’s Annual Network Plan Report (June 2010). 

Most of the sites are sited to provide PM10 concentration data at 

a neighborhood scale5 for the purpose of determining population 

exposure. The Craig Road site, however, is intended to capture 

the highest PM10 concentrations in Las Vegas Valley (i.e., at the 

neighborhood scale), and Green Valley and Palo Verde are 

intended to represent middle scale6 conditions. 

In table 1, below, we present a summary of AQS data 

collected at the nine PM10 sites currently in operation, as well 

as two sites (City Center in Las Vegas and Southeast Valley in 

Henderson), which have closed since 2006, and two sites (East 

Sahara in central Las Vegas and Walter Johnson in west Las 

Vegas), which no longer monitor PM10. As shown in table 1, only 

one PM10 exceedance was measured at any of the monitoring sites 

over the 2004-2006 period. 

Table 1: Summary Of Las Vegas Valley PM10 Monitoring Data, 2004-

2006 

Monitoring Site 

Highest 24-hour PM10

Concentration (μg/m3) 

Expected 

Exceedances 

 Per Year 

2004 2005 2006 2004-2006

City Center* 84 70 95 0.0 

Craig Road 151 149 157 0.4 

East Sahara* 89 99 93 0.0 

 

5

 In this context, “neighborhood scale” refers to conditions 

throughout some reasonably homogeneous urban sub-region with 

dimensions of a few kilometers. See 40 CFR part 58, appendix D, 

section 4.6. 

6

 In this context, “middle scale” refers to conditions 

characteristic of areas from 100 meters to several kilometers. 
13 

Green Valley 84 79 97 0.0 

J.D. Smith 122 144 136 0.0 

Joe Neal 135 124 122 0.0 

Lone Mountain 58 55 82 0.0 

Orr 88 75 94 0.0 

Paul Meyer 86 70 100 0.0 

Palo Verde 65 46 69 0.0 

Southeast Valley* 119 84 77 0.0 

Sunrise Acres 72 120 113 0.0 

Walter Johnson* 64 56 106 0.0 

PM10 NAAQS = 150 μg/m3. Exceedances shown in bold type. 

*

 Site is no longer in operation or is no longer monitoring PM10. 

Based on a review of air quality data during the three-year 

period ending with the December 31, 2006 attainment date (and 

summarized above in table 1), we find that the expected number 

of exceedances per year for Las Vegas Valley for 2004-2006 is 

0.4 days per year (based on the Craig Road monitoring site, the 

only one measuring an exceedance). This is less than an annual 

expected exceedance rate for the 24-hour PM10 NAAQS of 1.0 and 

represents attainment of the standard. EPA has therefore 

determined that the Las Vegas Valley PM10 nonattainment area 

attained the PM10 NAAQS by the applicable attainment date of 

December 31, 2006. 

B. Does more recent air quality data also show attainment? 

Although the attainment date for the Las Vegas Valley PM10

nonattainment area is December 31, 2006, EPA has also reviewed 

the air quality data collected at Clark County DAQEM’s PM10

monitoring sites in Las Vegas Valley from January 2007 through 
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the first quarter of 2010. During this period, the only 

exceedances of the 150 μg/m3 24-hour standard occurred at the 

Craig Road site, which monitored 24-hour concentrations of 203 

and 168 μg/m3 in 2008, but given the continuous nature of PM10

monitoring at the site, the annual expected exceedance rate, 

averaged over three years, has not exceeded 1.0. Thus, the data 

continue to show attainment of the 24-hour PM10 NAAQS in Las 

Vegas Valley since the end of 2006. 

III. EPA’s Final Action 

 Under section 188(b)(2) of the Clean Air Act, and based on 

complete, quality-assured data, we find that the Las Vegas 

Valley PM10 nonattainment area attained the 24-hour PM10 NAAQS by 

the applicable attainment date (December 31, 2006). We also find 

that the Las Vegas Valley nonattainment area is currently 

attaining the PM10 standard. This action is not a redesignation 

to attainment under CAA section 107(d)(3) because we have not 

yet approved a maintenance plan as meeting the requirements of 

section 175A of the CAA or determined that the area has met the 

other CAA requirements for redesignation. The PM10 classification 

and designation status in 40 CFR part 81 will remain serious 

nonattainment for Las Vegas Valley until such time as the State 

of Nevada meets the CAA requirements for redesignation of the 

valley to attainment. 
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 We are publishing this rule without prior proposal because 

the Agency views this as a noncontroversial action and 

anticipates no adverse comments. However, in the proposed rules 

section of this Federal Register publication, EPA is publishing 

a separate document that will serve as the proposal should 

adverse comments be filed. This action will be effective 

[Federal Register: Insert date 60 days after the publication 

date], without further notice unless the EPA receives relevant 

adverse comments by [Federal Register: Insert date 30 days after 

the publication date]. 

 If we receive such comments, then we will publish a 

document withdrawing the final rule and informing the public 

that the rule will not take effect. All public comments received 

will then be addressed in a subsequent final rule based on the 

proposed rule. We will not institute a second comment period. 

Parties interested in commenting should so at this time. If no 

such comments are received, the public is advised that this rule 

will be effective on [Federal Register: Insert date 60 days 

after the publication date] and no further action will be taken 

on the proposed rule. 

IV. Statutory and Executive Order Reviews 

This action merely makes a determination based on air 

quality data and does not impose any additional Federal 

requirements. For that reason, this action: 
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• Is not a “significant regulatory action” subject to review 

by the Office of Management and Budget under Executive 

Order 12866 (58 FR 51735, October 4, 1993); 

• Does not impose an information collection burden under the 

provisions of the Paperwork Reduction Act (44 U.S.C. 3501 

et seq.); 

• Is certified as not having a significant economic impact on 

a substantial number of small entities under the Regulatory 

Flexibility Act (5 U.S.C. 601 et seq.); 

• 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); 

• Does not have Federalism implications as specified in 

Executive Order 13132 (64 FR 43255, August 10, 1999); 

• Is not an economically significant regulatory action based 

on health or safety risks subject to Executive Order 13045 

(62 FR 19885, April 23, 1997); is not a significant 

regulatory action subject to Executive Order 13211 (66 FR 

28355, May 22, 2001); 

• Is not subject to requirements of Section 12(d) of the 

National Technology Transfer and Advancement Act of 1995 

(15 U.S.C. 272 note) because application of those 

requirements would be inconsistent with the CAA; and 
17 

• Does not provide EPA with the discretionary authority to 

address, as appropriate, disproportionate human health or 

environmental effects, using practicable and legally 

permissible methods, under Executive Order 12898 (59 FR 

7629, February 16, 1994). 

In addition, this rule does not have tribal implications as 

specified by Executive Order 13175 (65 FR 67249, November 9, 

2000), because it will not impose substantial direct costs on 

tribal governments or preempt tribal law. 

The Congressional Review Act, 5 U.S.C. 801 et seq., as 

added by the Small Business Regulatory Enforcement Fairness Act 

of 1996, generally provides that before a rule may take effect, 

the agency promulgating the rule must submit a rule report, 

which includes a copy of the rule, to each House of the Congress 

and to the Comptroller General of the United States. EPA will 

submit a report containing this action and other required 

information to the U.S. Senate, the U.S. House of 

Representatives, and the Comptroller General of the United 

States prior to publication of the rule in the Federal Register. 

A major rule cannot take effect until 60 days after it is 

published in the Federal Register. This action is not a “major 

rule” as defined by 5 U.S.C. 804(2). 

Under section 307(b)(1) of the Clean Air Act, petitions for 

judicial review of this action must be filed in the United 
18 

States Court of Appeals for the appropriate circuit by [Federal 

Register: Insert date 60 days after the publication date]. 

Filing a petition for reconsideration by the Administrator of 

this final rule does not affect the finality of this action for 

the purposes of judicial review nor does it extend the time 

within which a petition for judicial review may be filed, and 

shall not postpone the effectiveness of such rule or action. 

Parties with objections to this direct final rule are encouraged 

to file a comment in response to the parallel notice of proposed 

rulemaking for this action published in the proposed rules 

section of today's Federal Register, rather than file an 

immediate petition for judicial review of this direct final 

rule, so that EPA can withdraw this direct final rule and 

address the comment in the proposed rulemaking. This action may 

not be challenged later in proceedings to enforce its 

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

List of Subjects in 40 CFR Part 81 

 Environmental protection, Air pollution control, National 

parks, Particulate matter, Wilderness areas. 

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

________7/21/2010______ __________sb__________________

Dated: Keith Takata 

Acting Regional Administrator, 

EPA Region IX.