Clark County

Department of Air Quality

& Environmental Management

Annual Network Plan Report

June 2010
ii 

June 15, 2010 

Jared Blumenfeld, Regional Administrator 

U.S. Environmental Protection Agency, Region 9 

75 Hawthorne Street 

San Francisco, CA 94105 

RE: ANNUAL NETWORK PLAN 

Dear Mr. Blumenfeld: 

The Clark County Department of Air Quality and Environmental Management (DAQEM) has 

completed the “Annual Network Plan Report” required by Title 40, Part 58 of the Code of Federal Regulations. The plan has been available for public inspection since April 15, 2010, on our 

Web site at http://www.accessclarkcounty.com/depts/daqem/aq/Pages/aq_index.aspx. In addition, a newspaper announcement was published, the plan was available at the DAQEM front 

counter for review, and recipients were notified electronically from a list of environmental contacts. 

This report addresses the following objectives, set forth in guidance from the U.S. Environmental 

Protection Agency: 

1. Ambient Air Quality Monitoring Methodology. 

2. Network Design. 

3. Probe and Path Siting Criteria. 

4. Quality Assurance Requirement. 

5. Periodic Systems Audits and National Performance Audits. 

6. Corrective Action. 

DAQEM will continue to evaluate the monitoring network for program effectiveness in the following areas: effectively meeting users’ needs, effectively siting monitors, appropriate scale of 

representation, meeting air monitoring objectives, monitoring National Ambient Air Quality 

Standards, determining the effectiveness of air pollution control programs, and informing the 

public of air pollution levels. 

If you have any questions related to this report, please contact Yousaf Hameed, Air Quality 

Monitoring Supervisor, at (702) 379-4465. 

Respectfully, 

Mike Sword, P.E., CEM 

DAQEM Engineering Manager 
iii 

cc: 

Meredith Kurpius, Acting Manager, EPA Region 9 

Matthew Lakin, EPA Region 9 

Joseph Lapka, EPA Region 9 

Michael Flagg, EPA Region 9 

Mathew Plate, EPA Region 9 

Roy Ford, EPA Region 9 Grant Office 

Lewis Wallenmeyer, Director, DAQEM 

Tina Gingras, Assistant Director, DAQEM 

Yousaf Hameed, Monitoring Supervisor, DAQEM 
iv 

Executive Summary 

This annual plan reports the status of the Clark County Department of Air Quality and Environmental Management (DAQEM) air monitoring network. Reporting standards are outlined in Title 

40, Part 58 of the Code of Federal Regulations (40 CFR 58). 

The plan focuses on monitoring network changes that occurred in 2009, planned changes and 

improvements in 2010, efforts to improve data quality, and ways in which the information recorded by the network is disseminated. 

The 2009 network review identified potential deficiencies at two monitoring stations, along with 

options for correction. Shortcomings fell into the following categories: 

1. Spacing to roadways. 

2. Obstacle distance. 

DAQEM is continuing efforts to achieve total network compliance with the requirements outlined in 40 CFR 58. The section “Siting Criteria Deficiencies” contains an implementation schedule for corrective actions. 

In addition to network plan requirements, the U.S. Environmental Protection Agency released 

the revised final National Ambient Air Quality Standard for NO2 on February 9, 2010. This plan 

includes a discussion of the regulation changes that affect Clark County and its compliance status. 

This plan is an official request for the Region 9 office to determine that this plan meets all applicable requirements of 40 CFR Part 58. 
v 

Table of Contents 

Table of Contents ............................................................................................................................ v

List of Figures ................................................................................................................................ vi

Introduction ..................................................................................................................................... 1

Public Inspection Process ............................................................................................................... 4

Network Review Methodology ....................................................................................................... 5

Metropolitan Statistical Area .......................................................................................................... 6

Climatological Information ............................................................................................................. 7

Ambient Air Quality Monitoring Methodology ........................................................................... 10

Siting Criteria Deficiencies ........................................................................................................... 15

Design Values for 2009 ................................................................................................................ 16

Site and Instrument Information ................................................................................................... 17

Monitoring Start Dates in AQS..................................................................................................... 20

Monitoring Site Traffic Count Summary ...................................................................................... 22

Probe and Path Siting for 2009 ..................................................................................................... 23

Carbon Monoxide Monitoring Locations ..................................................................................... 51

Ozone Monitoring Locations ........................................................................................................ 52

Nitrogen Oxide Monitoring Locations .......................................................................................... 55

Continuous PM10 Monitoring Locations ....................................................................................... 56

Continuous PM2.5 Monitoring Locations ...................................................................................... 59

Filter-Based PM2.5 Monitoring Locations ..................................................................................... 61

Effect of New Regulations on Air Monitoring ............................................................................. 63

Summary of Monitoring Requirements ........................................................................................ 64

Quality Assurance Program .......................................................................................................... 67

National Performance Audits ........................................................................................................ 70

Network Modifications Completed in 2009 ................................................................................. 71

Network Modifications Proposed ................................................................................................. 72

Status of Monitoring Site Leases .................................................................................................. 76

Air Quality System Database Information .................................................................................... 78

Receptor-Measured Criteria Pollutant Trends .............................................................................. 80

Pollen Network ............................................................................................................................. 88
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List of Figures 

Figure 1 – Topographic Map ...........................................................................................................9

Figure 2 – Apex .............................................................................................................................24

Figure 3 – Boulder City .................................................................................................................26

Figure 4 – East Craig Road ............................................................................................................27

Figure 5 – East Sahara ...................................................................................................................29

Figure 6 – Green Valley .................................................................................................................31

Figure 7 – J.D. Smith .....................................................................................................................33

Figure 8 – Jean ...............................................................................................................................35

Figure 9 – Joe Neal ........................................................................................................................37

Figure 10 – Lone Mountain ...........................................................................................................38

Figure 11 – Mesquite .....................................................................................................................39

Figure 12 – Orr...............................................................................................................................41

Figure 13 – Palo Verde ..................................................................................................................43

Figure 14 – Paul Meyer..................................................................................................................45

Figure 16 – Sunrise Acres ..............................................................................................................46

Figure 17 – Walter Johnson ...........................................................................................................48

Figure 18 – Winterwood ................................................................................................................49

Figure 19 – Visibility Sites ............................................................................................................50

Figure 20 – Carbon Monoxide Monitoring Locations ...................................................................51

Figure 21 – Ozone Monitoring Locations in Las Vegas, Boulder City, and Apex ........................52

Figure 22 – Ozone Monitoring Location in Jean ...........................................................................53

Figure 23 – Ozone Monitoring Location in Mesquite ...................................................................54

Figure 24 – Nitrogen Oxide Monitoring Locations in Las Vegas .................................................55

Figure 25 – Continuous PM10 Monitoring Locations in Las Vegas, Boulder City, and Apex ......56

Figure 26 – Continuous PM10 Monitoring Location in Jean ..........................................................57

Figure 27 – Continuous PM10 Monitoring Location in Mesquite ..................................................58

Figure 28 – Continuous PM2.5 Monitoring Locations in Las Vegas and Apex .............................59

Figure 29 – Continuous PM2.5 Monitoring Location in Jean .........................................................60

Figure 30 – Filter-Based PM2.5 Monitoring Locations in Las Vegas ............................................61

Figure 31 – Filter Based PM2.5 Monitoring Location in Jean ........................................................62

Figure 32 – Carbon Monoxide Trends ...........................................................................................80

Figure 33 – Ozone Trends ..............................................................................................................81

Figure 34 – SO2 Trends..................................................................................................................82

Figure 35 – NO2 Trends .................................................................................................................83

Figure 36 – Continuous PM10 Trends ............................................................................................84

Figure 37 – Filter-Based PM2.5 FRM Trends .................................................................................85

Figure 38 – Continuous PM2.5 Annual Mean Trends .....................................................................86

Figure 39 – Continuous vs. Filter-Based PM2.5 Trends .................................................................87

Figure 40 – Pollen Sampling Locations in Las Vegas, Boulder City, and Apex ...........................89
vii 

Acronyms and Abbreviations 

Acronyms 

AQS Air Quality System 

ARM Approved Regional Method 

BAM Beta Attenuation Monitor 

CFR Code of Federal Regulations 

DAQEM Clark County Department of Air Quality & Environmental 

 Management 

EPA U.S. Environmental Protection Agency 

FEM Federal Equivalent Method 

FRM Federal Reference Method 

NAAQS National Ambient Air Quality Standard 

NAMS National Air Monitoring Station 

NCore National Core Monitoring Network 

PEP Performance Evaluation Program 

QA Quality Assurance 

QC Quality Control 

QCAS Quality Control and Assurance System 

RAAS Reference Ambient Air Sampler 

SASS Speciation Air Sampling System 

SLAMS State and Local Air Monitoring System 

TTP Through The Probe 

URG University Research Glassware 

Abbreviations 

CO carbon monoxide 

m/s meters per second 

mb millibar 

mph miles per hour 

NO2 nitrogen dioxide 

NOx nitrogen oxide 

O3 ozone 

Pb lead 

PM2.5 particulate matter 2.5 microns or less in aerodynamic diameter 

PM10 particulate matter 10 microns or less in aerodynamic diameter 

ppm parts per million 

SO2 sulfur dioxide 
1 

Introduction 

This document is a review of the Clark County Department of Air Quality and Environmental 

Management (DAQEM) air monitoring network, and serves as a monitoring network plan for future activities. It contains the following elements: 

1. Description of the climate of Clark County, Nevada. 

2. Documentation of ambient air quality monitoring methodology. 

3. Description of monitoring instruments in the network and general station information. 

4. Definition of the degree to which the network meets monitoring objectives. 

5. Description of probe and path siting compliance. 

6. Demonstration that each site monitoring particulate matter less than 2.5 microns in aerodynamic diameter (PM2.5) meets design value standards. 

7. Identification of ozone (O3) monitoring sites that exceed the 2009 ozone design value 

standard. 

8. Review of the Quality Assurance (QA) Program. 

9. Confirmation that the agency operates the number of monitors required by Title 40, Part 

58 of the Code of Federal Regulations (40 CFR 58). 

10. Description of network changes during calendar year 2009. 

11. Identification of projected network changes during calendar year 2010 and beyond. 

12. Description of the plan to correct guidance conflicts. 

During 2009, the following conditions existed: 

1. DAQEM operated air quality instruments to measure ambient concentrations of the following criteria pollutants: PM2.5, PM10, ozone, carbon monoxide (CO), and nitrogen 

oxides (NO, NO2, NOx). 

2. DAQEM monitored visibility as a special project. 

3. DAQEM counted pollen as a special project. 

4. DAQEM operated with the following program objectives: 

a. Ensure the network is monitoring representative data, and geographical and population factors are considered in managing the network. 

b. Make monitoring data readily accessible to the U.S. Environmental Protection Agency (EPA), regional and national air quality agencies, the general public, and stakeholders. 

c. Monitor visibility in the Las Vegas Valley using long path technology. 

d. Review analyzer placement for ozone boundaries, considering formation and transport. 

e. Improve forecasting methods for ozone, PM10, and PM2.5. 

f. Make efforts to update monitoring equipment when needed. 

g. Revise QCAS standard operating procedures (SOPs). 

h. Prepare National Core Monitoring Network (NCore) site for deployment. 

5. Clark County remained designated a serious nonattainment area for two criteria pollutants in Hydrographic Area 212, PM10 and CO. Clark County is in a nonattainment area 

for O3 and is awaiting an official EPA classification, which is expected in 2011. 
2 

 PM10: Clark County has demonstrated compliance with the NAAQS from the end of 

2006 through 2009, and is presumed to be in attainment. There was one exceedance in 

2007 (not flagged, not deemed questionable data) and two in 2008 (flagged, may be 

deemed questionable data). 

 PM2.5: Clark County is presumed to be in attainment of the NAAQS from 2004 through 

2009. DAQEM is continuing to assess PM2.5 Federal Reference Method (FRM) data to 

confirm. Currently, Clark County is designated as unclassifiable for PM2.5. Hydrographic 

Areas 212, 216, and 164A are designated attainment for PM2.5; all other parts of the 

county are designated unclassifiable for this pollutant. 

 CO: DAQEM has submitted a maintenance plan for CO. EPA's target date for approval is 

the end of June 2010, at which time Hydrographic Area 212 will be redesignated to attainment for CO. Clark County is requesting redesignation because it has been in attainment of the CO NAAQS since 2000. 

 Clark County was designated nonattainment for the 1997 ozone NAAQS (85 ppb) in 

April 2004. However, based on 2006-2009 monitoring data, Clark County is in attainment of the 1997 NAAQS. DAQEM is preparing a maintenance plan and redesignation 

request for the 1997 NAAQS; submittal to EPA is expected in late 2010. EPA reconsidered the 2008 NAAQS (75 ppb) in September 2009 and proposed a new primary and 

secondary standard in January 2010. The final rule will be promulgated on August 10, 

2010. 
3 

Below is a picture of the Air Quality Monitoring and QA Team. From left to right: Kris Simonian, Air Quality Monitoring Technician II; Pravin Pema, Air Quality Monitoring Technician II; 

Joe Biebrich, Air Quality Monitoring Technician II; Monte Symmonds, Senior Air Quality Monitoring Technician; Yousaf Hameed, Air Quality Monitoring Supervisor; David Dickens, Air 

Quality Monitoring Technician II; Matt Nelson, Air Quality Monitoring Technician II; Mickey 

Turner, Senior Air Quality Monitoring Technician; Phil Wiker, Senior Air Quality Monitoring 

Technician; and Mickey Palmer, Senior Air Quality Monitoring Technician and QA Officer. 

 
4 

Public Inspection Process 

This annual monitoring network plan report was published for public inspection 30 days prior to 

Clark County Board of County Commission approval and subsequent submittal to EPA, in compliance with 40 CFR 58.10. The plan was published and distributed on the DAQEM Web site, 

made available at the DAQEM front counter, advertised in the newspaper, and distributed to a 

list of environmental stakeholders. Public comments on this report may be sent to: 

Yousaf Hameed 

Air Quality Monitoring Supervisor 

Clark County DAQEM 

500 South Grand Central Parkway 

P.O. Box 555210 

Las Vegas, Nevada 89155 
5 

Network Review Methodology 

This annual monitoring network plan report was written, and the monitoring network was 

planned, according to “SLAMS / NAMS / PAMS Network Review Guidance,” published in 

1998 by the EPA Office of Air Quality Planning and Standards (EPA-454/R-98-003). The report 

team included supervisors, field technicians, data management specialists, planning staff, quality 

assurance technicians, and managers. 

The team completed the following tasks in preparing this network plan: 

1. Evaluated each station for pathway and probe siting criteria compliance. 

2. Reviewed Air Quality System (AQS) reports. 

3. Reviewed topographical maps. 

4. Reviewed historical trends in the monitoring network. 

5. Reviewed National Weather Service climate resources. 

6. Studied traffic count reports prepared by the Nevada Department of Transportation. 

7. Reviewed lease agreements. 

8. Calculated design values for ozone and PM2.5. 
6 

Metropolitan Statistical Area 

Clark County qualifies as one Metropolitan Statistical Area (40 CFR 81). The Las Vegas Valley 

contains the majority of the population for Clark County; smaller communities, such as Mesquite 

and Boulder City, do not qualify as Metropolitan Statistical Areas. 
7 

Climatological Information 

Information within this section was taken from the National Weather Service, Las Vegas climate 

book. 

1. Topography and History

Las Vegas is located in a broad desert valley in southern Nevada. Mountains surrounding the valley extend 2,000 to 10,000 feet above the valley floor. The Las Vegas Valley comprises about 

600 square miles and runs from northwest to southeast. It is bounded on the north by the Sheep 

Range, while Boulder City and the Lake Mead National Recreation Area are generally considered its southern extent. To the west are the Spring Mountains, which include Mt. Charleston, 

the region's highest peak at 11,918 feet. Several smaller ranges line the eastern rim of the valley, 

including the Muddy Mountains, the Black Mountains, and the Eldorado Range. For most of the 

Las Vegas metropolitan area, the valley floor slopes downward from west to east. This affects 

local climatology by driving variations in wind, precipitation, and storm runoff. 

Official weather observations have been recorded in Las Vegas since 1937, initially at Nellis 

Field in the northeast part of the valley. In late 1948, the U.S. Weather Bureau moved to McCarran Field (now McCarran International Airport), seven miles south of downtown Las Vegas. 

2. General Climatic Summary

The four seasons are actually well defined in Las Vegas, although they differ from the traditional 

view of seasonal variation. Summers display classic desert Southwest characteristics: daily high 

temperatures typically exceed 100F, with lows in the 70s. The summer heat is tempered somewhat by the extremely low relative humidity; however, humidity can increase markedly for several weeks each summer in association with a moist "monsoonal flow" from the south, typically 

during July and August. These moist winds support the development of spectacular desert thunderstorms associated with significant flash flooding and/or strong downburst winds. 

Winters, overall, are mild and pleasant. Afternoon temperatures average near 60F and skies are 

mostly clear. Pacific storms occasionally produce rainfall in Las Vegas, but in general, the Sierra 

Nevada Mountains of eastern California and the Spring Mountains immediately west of the Las 

Vegas Valley act as effective barriers to moisture. 

Snow accumulation is rare in Las Vegas. Flurries are observed once or twice during most winters, but snowfall of an inch or more occurs only once every four to five years. However, freezing temperatures occur regularly each year: the valley has a 30-year average of 24 days with low 

temperatures at or below 32. Snowfall is common in the mountains surrounding Las Vegas, 

with the Spring Mountains receiving between 5 and 10 feet annually. The spring and fall seasons 

are generally considered ideal. Although sharp temperature changes can occur, outdoor activities 

are seldom hampered. 

Strong winds are the most persistent weather hazard in the area. Winds over 50 miles per hour 

(mph) are infrequent, but can occur with vigorous storms. Winter and spring wind events often 
8 

generate widespread areas of blowing dust and sand. Strong wind episodes in the summertime 

are usually connected with thunderstorms, and are thus isolated and localized. Prevailing wind 

direction is typically either southwest or north unless associated with a thunderstorm outflow. 

Regional transport and local influences produce higher ozone concentrations on the west and 

northwest sides of the valley. Ozone episodes in the Las Vegas Valley are generally characterized by a surface (thermal) low pressure system extending over Arizona, southern California, 

and Nevada; ridging of 500 millibars (mb) over the southwest or central United States; and 

southwesterly surface flow during the afternoon hours, accompanied by ample sunshine and high 

temperatures. Superimposed on the synoptic-scale meteorological conditions are the local, terrain-induced mesoscale meteorological features. Together, these determine the horizontal and 

vertical advection and dispersion of pollutants and their eventual removal from the Las Vegas 

Valley. 

3. Synoptic Meteorology

Based on a National Meteorological Center modeling analysis at 500 mb, a broad, flat ridge of 

pressure over the central U.S. is dominant during the summer season. Winds at this level, as indicated by the Mercury/Desert Rock Weather Service Meteorological Observatory radiosonde, 

are normally westerly and characterized by moderate (10-15 m/s) wind speeds. The center’s surface analyses indicate that southern Nevada is enveloped by a thermal low-pressure system. 
9 

Figure 1 – Topographic Map 
10 

Ambient Air Quality Monitoring Methodology 

DAQEM’s Monitoring Section operated 16 monitoring stations in Clark County during 2009. 

The types of monitors vary from station to station. The network primarily consists of State and 

Local Air Monitoring Stations (SLAMS), with a neighborhood-scale focus intended to assess 

exposure levels of the general population. The network also characterizes pollution transport and 

background levels. It contains subnetworks for the EPA criteria pollutants PM10, PM2.5,CO, O3,

and NO2. 

Continuous Particulate Matter Monitors 

The sampling methodology employs the continuous Thermo Electron FH 62 C14 series monitor, 

which uses carbon-14 as the beta source. All continuous PM2.5 monitors have a Very Sharp Cut 

Cyclone as their second stage separator. 

Particulate Matter of 10 Microns or Less 

During 2009, 13 continuous PM10 monitors operated in Clark County. Nine operated within the 

Las Vegas Valley; the Jean, Boulder City, Apex, and Mesquite monitors operated outside the 

valley. The maps in the section titled “Continuous PM10 Monitoring Locations” show the locations of the monitors in the PM10 monitoring network (Figures 25-27). 

A quality control (QC) flow rate verification is conducted on the continuous PM10 monitors 

every two weeks, exceeding the EPA requirement of once per month. A QA flow rate audit is 

conducted on the monitors once every six months. 

The following table shows the spatial scale and monitoring objective for each PM10 monitor. 

Site Spatial Scale Objective 

Green Valley Middle Population exposure 

Mesquite Middle Population exposure 

Palo Verde Middle Population exposure 

Jean Regional Background 

Apex Regional Source 

Craig Road Neighborhood Highest concentration 

All others Neighborhood Population exposure 

Particulate Matter of 2.5 Microns or Less 

In 2009, DAQEM operated six continuous PM2.5 monitors in Clark County. The maps in the section titled “Continuous PM2.5 Monitoring Locations” show the locations of the monitors in the 

continuous PM2.5 monitoring network (Figures 28 and 29). 
11 

In accordance with 40 CFR 58.30, DAQEM has determined that all PM2.5 monitoring sites are 

representative of area-wide concentrations and not directly impacted by unique sources. The 

Apex Monitoring Station may be an exception due to the close proximity of emission sources. 

A QC flow rate verification is conducted on the continuous PM2.5 monitors every two weeks, exceeding EPA requirements. A QA flow rate audit is conducted on the monitors once every six 

months. 

The following table shows the spatial scale and monitoring objective for each PM2.5 monitor. 

Site Spatial Scale Objective 

Craig Road Neighborhood Population exposure 

J.D. Smith Neighborhood Population exposure 

Sunrise Acres Neighborhood Highest concentration 

Green Valley Middle Population exposure 

Jean Regional General/background 

Apex Regional Source-oriented 

Filter-Based Particulate Matter Samplers 

The PM2.5 FRM and the PM2.5 Speciation samplers, the latter of which includes the University 

Research Glassware (URG) carbon channel sampler, are the only filter-based monitoring instruments DAQEM employs. The maps in the section titled “Filter-Based PM2.5 Monitoring Locations” show the locations of the samplers in the PM2.5 FRM monitoring network (Figures 30 and 

31). Sampling methodology employs the filter-based FRM Andersen Model 300 Reference Ambient Air Sampler (RAAS). 

DAQEM operates a gravimetric laboratory that weighs PM2.5 FRM filters. 

Particulate Matter of 2.5 Microns or Less 

In 2009, three filter-based PM2.5 FRM samplers operated as listed in the table below. 

Site Schedule

Sunrise Acres One in three days 

Sunrise Acres (collocated) One in six days 

Jean One in three days 

J.D. Smith One in three days 

A QC flow rate verification is conducted on the filter-based PM2.5 FRM samplers once a month; 

a QA flow rate audit is conducted on the samplers once every six months. 

The following table shows the spatial scale and monitoring objective for each routine filter-based 

PM2.5 FRM sampler. 
12 

Site Spatial Scale Objective 

Jean Regional Background 

Sunrise Acres Neighborhood Highest concentration 

J.D. Smith Neighborhood Population exposure 

In accordance with 40 CFR 58.10, DAQEM will notify the public if a PM2.5 monitor violates the 

NAAQS, or if a community monitoring zone (as defined in the Federal Register) is created or 

changed. DAQEM will use a two-part process, similar to the current network plan public inspection process, to provide notification of a proposed monitoring zone change: (1) post to its Web 

site a review of the PM2.5 monitoring network with the changes being considered, and (2) solicit 

feedback from the community. DAQEM will respond to any public comments and take all comments into consideration before making changes to the PM2.5 monitoring network. The only exceptions to this process will be a lost lease or a 30-day notice from the property owner to vacate 

the site. 

40 CFR 58.30 describes certain types of microscale PM2.5 sites as unsuitable for comparison to 

the annual NAAQS. DAQEM does not operate a microscale PM2.5 site, so all its FRM PM2.5

monitors are suitable for NAAQS comparisons. 

Speciation 

DAQEM operates a speciation sampler in conjunction with a carbon channel sampler at the East 

Craig Road site (32-003-0022). Under an EPA contract, the Research Triangle Institute analyzes 

speciation samples and reports the results to the AQS. 

Carbon Monoxide 

The map in the section titled “Carbon Monoxide Monitoring Locations” shows the locations of 

the monitors in the CO monitoring network (Figure 20). DAQEM uses API 300 Series monitors 

with gas filter correlation. 

DAQEM conducts a three-point QC check on the CO monitors every week and calibrates them 

quarterly. Twenty-five percent of the CO monitors undergo a QA audit every quarter, and all CO 

monitors undergo an audit at least once each year. 

The following table shows the spatial scale and monitoring objective for each CO monitor. 

Site Spatial Scale Objective 

Sunrise Acres Neighborhood Highest concentration 

All others Neighborhood Population exposure 

Ozone 

In 2009, DAQEM operated 13 ozone monitors in Clark County. Nine operated within the Las 

Vegas Valley; the Jean, Apex, Boulder City, and Mesquite monitors operated outside the valley. 

The maps in the section titled “Ozone Monitoring Locations” show the locations of monitors in 
13 

the ozone monitoring network (Figures 21-23). Clark County uses API 400 Series ultraviolet absorption monitors. 

The majority of the ozone network in Clark County was designed for the one-hour ozone standard. That is now used to calculate eight-hour (rolling average) values for comparison to the current ozone NAAQS. 

DAQEM’s ozone projects include: 

 “Ozone Characterization Study.” 

 “Clark County Regional Ozone & Precursor Study.” 

 “Southwest Desert Las Vegas Ozone Transport Study.” 

 Biogenic emissions inventory. 

 Emission inventory of volatile organic compounds from consumer products. 

 Establishment of upper air wind measurements in Clark County. 

 Characterization of 2009 wildfire impacts on air quality in Clark County. 

DAQEM is planning another wildfire study in the summer of 2010 to evaluate how smoke 

plumes affect Clark County with respect to ozone precursors and ozone formation. The goal is to 

further characterize smoke plume impacts on ozone concentrations by showing a quantifiable relationship between ozone, PM2.5, and levoglucosan, a chemical marker for wildfires. DAQEM 

anticipates these wildfire studies will contribute to successful exceptional event demonstration 

packages. In addition, there is evidence that introducing smoke into the analytical bench of ozone 

analyzers can cause an artificial positive bias. Thus far DAQEM has not been able to establish 

this relationship, but it will continue to investigate. DAQEM may deploy a chemiluminescence 

ozone analyzer in the 2010 study, since it uses a measurement principle that is not affected by 

particulate interference. All instrumentation deployed as part of the wildfire study will be operated as special purpose monitoring (SPM). 

DAQEM conducts a three-point QC check on the ozone monitors every week and calibrates 

them quarterly. Twenty-five percent of the ozone monitors undergo a QA audit every quarter, 

and all ozone monitors undergo an audit at least once each year. 

The following table shows the spatial scale and monitoring objective for each monitor. 

Site Spatial Scale Objective 

Apex Regional Regional transport 

Joe Neal Neighborhood Highest concentration 

Jean Regional Regional transport 

All others Neighborhood Population exposure 

Nitrogen Oxides 

In 2009, DAQEM operated two nitrogen oxide monitors in Clark County. All nitrogen oxide 

monitors were operated within the Las Vegas Valley. The map in the section titled “Nitrogen 
14 

Oxide Monitoring Locations” shows the locations of monitors in the nitrogen oxide monitoring 

network (Figure 24). DAQEM uses API 200 Series monitors with gas phase chemiluminescence. 

DAQEM conducts a three-point QC check on the nitrogen oxide monitors every week and calibrates them quarterly. Twenty-five percent of the nitrogen oxide monitors undergo a QA audit 

every quarter, and all nitrogen oxide monitors undergo an audit at least once each year. 

The table below shows the spatial scale and monitoring objective for each monitor. 

Site Spatial Scale Objective 

J.D. Smith Neighborhood Highest concentration 

Joe Neal Neighborhood Population exposure 
15 

Siting Criteria Deficiencies 

DAQEM identified the following deficiencies in the 2009 review of the network. 

Site Roadway Obstacle Distance

E. Sahara CO 

Walter Johnson Water cooling tower 15’ from inlet 

The table below shows the schedule to correct the identified siting deficiencies. 

Deficiency Site/Monitor Corrective Action Schedule

Spacing from roads E. Sahara/CO Move to Jerome Mack Middle School 2010

Obstacle distance Walter Johnson/O3 DAQEM will monitor data for impacts 

from cooling tower 2010

Spacing from roads: 

DAQEM will evaluate spacing and attempt to comply with 40 CFR 58, Appendix E. DAQEM 

will consider one or more of the following options: 

1. Relocate the site. 

2. Shut down the site. 

Obstacle distance: 

DAQEM will evaluate the obstacle distance problem and will attempt to comply with 40 CFR 

58, Appendix E. DAQEM will consider the following options: 

1. Increase the height of the probe so the obstacle is no longer an issue. 

2. Relocate the site. 

3. Shut down the site. 
16 

Design Values for 2009 

The following table compares ozone design values with the NAAQS standard. 

Station Ozone Design Value (ppm) NAAQS Standard (ppm)

E. Craig Road 0.072 .075 

Winterwood 0.072 .075 

Apex 0.074 .075 

Lone Mountain 0.076 .075 

Palo Verde 0.075 .075 

Jean 0.076 .075 

Paul Meyer 0.077 .075 

Boulder City 0.072 .075 

J.D. Smith 0.073 .075 

Walter Johnson 0.078 .075 

Joe Neal 0.078 .075 

Mesquite .0.065 .075 

Orr 0.074 .075 

Note: ppm = parts per million. 

The following table compares annual PM2.5 design values with the NAAQS standard. 

Station PM2.5 Design Value (g/m3) NAAQS Standard (g/m3) 

Sunrise Acres 9.4 15 

Jean 4.1 15 

J.D. Smith 8.5 15 

The following table compares 24-hour PM2.5 design values with the NAAQS standard. 

Station PM2.5 Design Value (g/m3) NAAQS Standard (g/m3) 

Sunrise Acres 21 35 

Jean 11 35 

J.D. Smith 18 35 

40 CFR 58.30 describes certain types of microscale PM2.5 sites as unsuitable for comparison to 

the annual NAAQS. DAQEM does not operate a microscale PM2.5 site, so all its FRM PM2.5

monitors are suitable for NAAQS comparisons. 
17 

Site and Instrument Information 

Site Information 

Apex (32-003-0022). The site is located in Apex Valley, approximately 25 miles northeast of Las 

Vegas. Its primary purpose is to monitor ambient impacts of emissions from nearby gravel 

processing and power plants, and pollutant flow out of the Las Vegas Valley. This monitoring 

site is generally downwind from Las Vegas and serves as an indicator of pollutant transport flow 

out of the Las Vegas Valley; this site is the only DAQEM monitoring station in the Apex Valley. 

Boulder City (32-003-0601). The site is located in Boulder City, approximately 25 miles southeast of Las Vegas. It was established at the request of Boulder City government officials and residents. The primary pollutants of interest are O3 and PM10. 

Craig Road (32-003-0020). The site is located in the city of North Las Vegas. It was established 

to comply with permit conditions related to potentially high emissions of O3 precursors. Although that emission source no longer exists, the site continues to monitor O3, PM10, and PM2.5; 

it periodically violates the PM10 24-hour standard. Because of other DAQEM efforts and the periodic PM10 exceedances, the speciation sampler was moved to this site in March 2007 from the 

Sunrise Acres site. This site has not experienced a PM10 exceedance since May 2008. 

 

Green Valley (32-003-0298). The site is located in Henderson. It was established because of citizen complaints about dust emissions from a gravel processing plant, and continues to monitor 

PM10 and PM2.5. 

J.D. Smith (32-003-2000). The site is located in the City of North Las Vegas. It replaced the old 

McDaniel and Post Office PM sites. The site monitors gaseous (NOx, CO, and O3) and particulate (PM10 and PM2.5) pollutants using both filter-based and continuous methodologies. 

Jean (32-003-1019). The site is located in Jean, approximately 30 miles south of Las Vegas. Its 

primary purpose is to monitor transport pollutants from southern California: O3, PM10, and continuous and filter-based PM2.5. 

Joe Neal (32-003-0075). The site is located in the northwest part of Las Vegas. Its primary objective is to monitor O3, although a NOx monitor has also been operating at this location since 

January 2008. The topography is such that the summertime loft brings higher O3 and precursor 

levels toward this site from the east end of the Las Vegas Valley. The primary reason for this installation was to monitor O3 precursors in a high O3 concentration area, and to support DAQEM 

modeling efforts. PM10 was initially deployed at this site due to population growth in this part of 

the valley; this site continues to serve its intended population. 

Lone Mountain (32-003-0072). The site is located in the northwest part of Las Vegas. Its primary 

objective is to monitor O3. The topography is such that the summertime loft brings higher O3 and 

precursor levels toward this site from the east end of the Las Vegas Valley. DAQEM initiated 

PM10 monitoring here because of gravel processing to the west/northwest of the monitoring site. 
18 

East Sahara (32-003-0539). The site, centrally located in the Las Vegas Valley, is one of the 

oldest sites. Its primary objective is to monitor CO. 

Mesquite (32-003-0023). The site is located in Mesquite, approximately 70 miles north of Las 

Vegas; it monitors O3 and PM10. This station is located along a transport and exit corridor for jurisdictional boundaries. 

 

Orr (32-003-1021). The site is the replacement for the East Flamingo site, which was terminated 

because the lease was lost and it was too close to the road to meet its original O3 monitoring objective. DAQEM began monitoring O3 at Orr in April 2006, and continues monitoring CO and 

PM10 there. 

Paul Meyer (32-003-0043). The site is located in the southwest part of Las Vegas. Its primary 

objective is to monitor O3. The topography is such that the summertime loft brings higher O3 and 

precursor levels toward this site from the east end of the Las Vegas Valley. PM10 is also monitored at this location. 

Palo Verde (32-003-0073). The site is located in the west part of Las Vegas. Its primary objective is to monitor O3. The topography is such that the summertime loft brings higher O3 and precursor levels toward this site from the east end of the Las Vegas Valley. The site also monitors 

PM10. 

Sunrise Acres (32-003-0561). The site is near the center of the Las Vegas Valley. Monitoring 

began here as part of a CO study in the 1990s, and its primary objective is still to monitor CO. 

After the lease for the East Charleston site was lost, all monitoring activities at that site were 

transferred to Sunrise Acres. This site monitors particulate pollutants (PM10 and PM2.5) using 

both filter-based and continuous methodologies. The site also utilizes PM2.5 FRM samplers as the 

primary and collocated sampling site. 

Walter Johnson (32-003-0071). The site is located on the west side of Las Vegas. Its primary objective is to monitor O3. The topography is such that the summertime loft brings high O3 and 

precursor levels towards this site from the east end of the Las Vegas Valley. 

Winterwood (32-003-0538). The site is located on the east side of Las Vegas, and is one of the 

oldest sites. Its primary objective is to monitor CO and O3. 

None of the DAQEM monitoring sites are located near furnaces or incinerators. 
19 

Instrument Information 

Items monitored: 

1. CO 

2. O3 

3. NOx 

4. PM10 continuous 

5. PM2.5 continuous 

6. PM2.5 FRM, manual method 

7. PM2.5 species, manual method 

8. Visibility 

9. Meteorological parameters 

Monitor type: 

1. CO: gas filter correlation (non-dispersive infrared). 

2. O3: ultraviolet absorption. 

3. NOx: chemiluminescent gas phase reaction of NOx and O3. 

4. PM10 and PM2.5 C-14 continuous monitor: Beta Attenuation Monitor (BAM). 

5. PM2.5 RAAS manual method: filter-based. 

6. PM2.5 Speciation Air Sampling System (SASS) and URG manual methods: filter-based. 

7. Visibility: transmissometer. 

The table below shows DAQEM fulfillment of FRM and NAAQS instrumentation requirements. 

Pollutant Instrument FRM FEM SPM Comparable to NAAQS

CO API 300 Series X Yes 

O3 API 400 Series X Yes 

NO2 API 200 Series X Yes 

SO2 Monitor Lab ML9850 X Yes 

PM10 Thermo Electron C14 X Yes 

PM2.5 Thermo Electron C14 X No 

PM2.5 Thermo Andersen RAAS X Yes 

Note: FRM = Federal Reference Method; FEM = Federal Equivalence Method; SPM = Special Purpose Monitor. 

Most DAQEM air monitoring stations are equipped with a 10-meter meteorological tower that 

has an ultrasonic wind speed and wind direction sensor and an ambient temperature sensor at 10 

meters. Some meteorological monitoring stations also have relative humidity, precipitation, and 

solar radiation sensors. 
20 

Monitoring Start Dates in AQS 

The table below shows monitoring start dates in AQS. 

Site Name Site ID Parameter Description AQS Parameter

Code POC Date Sampling Began 

Apex 0022 Nitrogen dioxide 42602 1 01-Jan-1998 

Apex 0022 Ozone 44201 1 01-Jan-1998 

Apex 0022 PM10 total 0-10 μm STP1 81102 1 01-Jan-1998 

Apex 0022 PM2.5 - local conditions C-14 88502 3 23-Jan-2007 

Boulder City 0601 Ozone 44201 1 01-Jul-1998 

Boulder City 0601 PM10 total 0-10 μm STP 81102 1 01-Jan-1998 

E. Craig Road 0020 Ozone 44201 1 01-Jan-1992 

E. Craig Road 0020 PM10 total 0-10 μm STP 81102 1 01-Jan-1998 

E. Craig Road 0020 PM2.5 - local conditions C-14 88101 3 01-Jan-2003 

E. Craig Road 0020 PM2.5 - speciation 88101 5 --- 

E. Sahara 0539 Carbon monoxide 42101 1 01-Jan-1998 

E. Sahara 0539 Sulfur dioxide 42401 1 01-Jan-1998 

E. Sahara 0539 Nitrogen dioxide 42602 1 01-Jan-1998 

E. Sahara 0539 PM10 total 0-10 μm STP 81102 1 01-Jan-1995 

Green Valley 0298 PM10 total 0-10 μm STP 81102 1 01-Jan-1998 

Green Valley 0298 PM2.5 - local conditions C-14 88101 3 01-Jan-2003 

J.D. Smith 2002 Nitrogen dioxide 42602 1 01-Oct-1998 

J.D. Smith 2002 Carbon monoxide 42101 1 01-Oct-1998 

J.D. Smith 2002 Ozone 44201 1 01-Oct-1998 

J.D. Smith 2002 PM10 total 0-10 μm STP 81102 1 01-Jan-1998 

J.D. Smith 2002 PM2.5 - local conditions 88101 1 01-Jan-1999 

J.D. Smith 2002 PM2.5 - local conditions C-14 88502 3 01-Jan-2003 

Jean 1019 Ozone 44201 1 01-Aug-1998 

Jean 1019 PM10 total 0-10 μm STP 81102 1 01-Jan-1995 

Jean 1019 PM2.5 - local conditions 88101 1 01-Jan-1999 

Jean 1019 PM2.5 - local conditions C-14 88502 3 26-May-2007 

Joe Neal 0075 Ozone 44201 1 01-Jul-2000 

Joe Neal 0075 PM10 total 0-10 μm STP 81102 1 01-Jan-2001 

Joe Neal 0075 Nitrogen dioxide 42602 1 01-Jan-2008 

Lone Mountain 0072 Ozone 44201 1 01-Jan-1998 

Lone Mountain 0072 PM10 total 0-10 μm STP 81102 1 01-Jan-1998 

Mesquite 0023 Nitrogen dioxide 42602 1 01-Nov-2001 

Mesquite 0023 Ozone 44201 1 01-Oct-2001 

Mesquite 0023 PM10 total 0-10 μm STP 81102 1 01-Nov-2001 

Orr 1021 Carbon monoxide 42101 1 01-Oct-2002 

Orr 1021 Ozone 44201 1 01-Apr-2006 

Orr 1021 PM10 total 0-10 μm STP 81102 1 01-Oct-2002 
21 

Site Name Site ID Parameter Description AQS Parameter

Code POC Date Sampling Began 

Palo Verde 0073 Nitrogen dioxide 42602 1 01-Aug-1998 

Palo Verde 0073 Ozone 44201 1 01-Jul-1998 

Palo Verde 0073 PM10 total 0-10 μm STP 81102 1 01-Jul-1998 

Paul Meyer Park 0043 Ozone 44201 1 01-Jul-1998 

Paul Meyer Park 0043 PM10 total 0-10 μm STP 81102 1 01-Jan-1998 

Southeast Valley 0007 Ozone 44201 1 01-Jan-1980 

Southeast Valley 0007 PM10 total 0-10 μm STP 81102 1 01-Jan-1998 

Sunrise Acres 0561 Carbon monoxide 42101 1 01-Oct-1996 

Sunrise Acres 0561 PM10 total 0-10 μm STP 81102 1 17-Apr-2004 

Sunrise Acres 0561 PM2.5 - local conditions 88101 1 14-Apr-2004 

Sunrise Acres 0561 PM2.5 - local conditions 88101 2 14-Apr-2004 

Sunrise Acres 0561 PM2.5 - local conditions C-14 88101 3 01-Jul-2005 

Walter Johnson 0071 Ozone 44201 1 01-Aug-1998 

Walter Johnson 0071 PM10 total 0-10 μm STP 81102 1 01-Jul-1995 

Winterwood 0538 Carbon monoxide 42101 1 01-Jan-1998 

Winterwood 0538 Ozone 44201 2 01-Jul-1979 

Note: POC = parameter occurrence code; STP = standard temperature and pressure. 
22 

Monitoring Site Traffic Count Summary 

The table below provides traffic count information near monitoring sites. 

Site Name Distance to Nearest 

Roadway1

Traffic Study 

Counts from 

Nearest Roadway2

Traffic Counts 

Estimated by 

Operator 

Maximum Traffic 

Counts for Distance to 

Roadway3

Apex 108 meters to U.S. Hwy. 93 2,100 70,000/30,000 

Boulder City 57 meters to Industrial 18,000 40,000/20,000 

E. Craig Road 34 meters to Mitchell 4,400 20,000/15,000 

E. Sahara 48 meters to Sahara 25,000 20,000/20,000 

Green Valley 12.2 meters to Santiago 4,600 10,000/10,000 

J.D. Smith 180 meters to Bruce 7,200 70,000/60,000 

Jean 1287 meters to 

State Hwy. 161 2,000 110,000/60,000 

Joe Neal 12.2 meters to Rebecca Not available 4,200 10,000/10,000 

Lone Mountain 50 meters to Valadez 5,400 40,000/20,000 

Mesquite 9.2 meters to Old Mill Rd. Not available 1,000 ≤1,000/≤10,000 

Orr 11.9 meters to Katie Not available 5,000 10,000/10,000 

Palo Verde 14.7 meters to Pavilion Not available 7,800 10,000/10,000 

Paul Meyer 102 meters to New Forrest Dr. Not available 5,200 70,000/30,000 

Sunrise Acres 128 meters to Sunrise Not available 3,000 70,000/40,000 

Walter Johnson 13 meters to 

Villa Monterrey 11,000 10,000/≤10,000 

Winterwood 33.8 meters to Club House Dr. Not available 400 20,000/15,000 1

Distance from monitoring path to edge of roadway. 

2

Traffic study counts taken or derived from nearest study performed by the Nevada Department of Transportation. 3

Tables E-1 & E-2 in 40 CFR 58, Appendix E, are used to determine the minimum and maximum distance from the edge of the 

roadway to the monitoring path or probe. Table E-1 = ozone and nitrogen oxides for urban and neighborhood scale; Table E-2 = 

CO for neighborhood scale. 
23 

Probe and Path Siting for 2009 

1. Apex 

2. Boulder City 

3. East Craig Road 

4. East Sahara 

5. Green Valley 

6. J.D. Smith 

7. Jean 

8. Joe Neal 

9. Lone Mountain 

10. Mesquite 

11. Orr 

12. Palo Verde 

13. Paul Meyer 

14. Sunrise Acres 

15. Walter Johnson 

16. Winterwood 
24 

Figure 2 – Apex 

Type: SLAMS 

Apex (AP) (32-003-0022) 

Location: 12101 U.S. Highway 93, Las Vegas, NV 89030 

Closest Roads: I-15, U.S. Highway 93 

UTM X-Coordinate: 667652.800; UTM Y-Coordinate: 4004823.000 

Operative Schedule: 24 hours 

Sampling Method: Ozone: Ultraviolet Absorption, API 400 

PM10: Beta Attenuation, Thermo Electron FH 62 C14 

PM2.5: Beta Attenuation, Thermo Electron FH 62 C14 

Predominant Wind Direction: South 

Photograph Direction: South 

 PM10 PM2.5 Continuous O3

Spatial scale Neighborhood Neighborhood Regional 

Monitoring objective Source-oriented Source-oriented Regional transport 

Vertical probe placement 4.8 m 4.9 m 3.8 m 

Unrestricted airflow 360° 360° 360° 

Spacing from trees None None None 

Spacing from station to road 108 m 108 m 108 m 

Distance between collocated 

monitors 1.4 m 1.4 m — 

Ground cover Native desert Native desert — 

Spacing from supporting structure — — 1.3 m 
25 

 PM10 PM2.5 Continuous O3

Obstructions on roof None None — 

Obstacle distance None None None 

Probe material — — Teflon 

Residence time — — 1.9 s 
26 

Figure 3 – Boulder City 

Type: SLAMS 

Boulder City (BC) (32-003-0601) 

Location: 1005 Industrial Rd., Boulder City, NV 89005 

Closest Roads: U.S. Hwy. 93, Industrial Rd. 

UTM X-Coordinate: 694175.800; UTM Y-Coordinate: 3983670.000 

Operative Schedule: 24 hours 

Sampling Method: Ozone: Ultraviolet Absorption, API 400E 

PM10: Beta Attenuation, Thermo Electron FH 62 C14 

Predominant Wind Direction: Southwest 

Photograph Direction: Northwest 

 PM10 O3

Spatial scale Neighborhood Neighborhood 

Monitoring objective Population exposure Population exposure 

Vertical probe placement 5.2 m 4.1 m 

Unrestricted airflow 360° 360° 

Spacing from trees None None 

Spacing from station to road 58.0 m 58.0 m 

Distance between collocated monitors Not applicable — 

Ground cover Paved, native desert — 

Spacing from supporting structure — 1.0 m 

Obstructions on roof None — 

Obstacle distance None None 

Probe material — Teflon 

Residence time — 4.9 s 
27 

Figure 4 – East Craig Road 

Type: SLAMS 

E. Craig Rd (CR) (32-003-0020) 

Location: 4701 Mitchell St., North Las Vegas, NV 89081 

Three Closest Roads: N. Walnut Rd., E. Craig Rd., Mitchell St. 

UTM X-Coordinate: 671333.900; UTM Y-Coordinate: 4012829.000 

Operative Schedule: 24 hours 

Sampling Method: Ozone: Ultraviolet Absorption, API 400A 

PM2.5: Beta Attenuation, Thermo Electron FH 62 C14 

PM10: Beta Attenuation, Thermo Electron FH 62 C14 

PM2.5: Speciation, MetOne SASS and URG 3000 

Predominant Wind Direction: South 

Photograph Direction: West 

 PM10 O3 Speciation PM2.5 Continuous

Spatial scale Neighborhood Neighborhood Neighborhood Neighborhood 

Monitoring objective Highest 

concentration 

Population 

exposure 

Population 

exposure 

Population 

exposure 

Vertical probe placement 5.7 m 4.6 m 5.7 m 5.7 m 

Unrestricted airflow 360° 360° 360° 360° 

Spacing from trees None None None None 

Spacing from station to road 34.0 m 34.0 m 34.0 m 34.0 m 

Distance between collocated 

monitors 1.5 m — 1.9 m 1.5 m 
28 

 PM10 O3 Speciation PM2.5 Continuous

Ground cover Paved, unpaved — Paved, unpaved Paved, unpaved 

Spacing from supporting structure — 1.2 m — — 

Obstructions on roof None — None None 

Obstacle distance 15 m 60 m 15 m 15 m 

Probe material — Teflon — — 

Residence time — 5.0 s — — 
29 

Figure 5 – East Sahara 

Type: SLAMS 

East Sahara (ES) (320030539) 

Location: 4001 E. Sahara Ave., Las Vegas, NV 89104 

Three Closest Roads: S. Lamb Blvd., S. Sandhill Rd., S. Walnut Rd. 

UTM X-Coordinate: 672250.100; UTM Y-Coordinate: 4001593.000 

Operative Schedule: 24 hours 

Sampling Method: Carbon Monoxide: Gas Filter Correlation API 300E 

Predominant Wind Direction: Southwest 

Photograph Direction: East 

Changes: Proposed move to Jerome Mack Middle School and new shelter, candidate for NCore 

operations 

 CO 

Spatial scale Neighborhood 

Monitoring objective Population exposure 

Vertical probe placement 4.3 m 

Unrestricted airflow 360° 

Spacing from trees 39.5 m 

Spacing from station to road 45.7 m 

Distance between collocated monitors — 

Ground cover Asphalt, gravel 

Spacing from supporting structure 1.3 m 

Obstructions on roof — 
30 

 CO 

Obstacle distance — 

Probe material — 

Residence time 2.7 s 
31 

Figure 6 – Green Valley 

Type: SLAMS 

Green Valley (GV) (32-003-0298) 

Location: 298 Arroyo Grande Blvd., Henderson, NV 89014 

Three Closest Roads: Arroyo Grande Blvd., Santiago Dr., N. Stephanie St. 

UTM X-Coordinate: 675390.700; UTM Y-Coordinate: 3991108.000 

Operative Schedule: 24 hours 

Sampling Method: PM2.5: Beta Attenuation, Thermo Electron FH 62 C14 

PM10: Beta Attenuation, Thermo Electron FH 62 C14 

Predominant Wind Direction: Southwest 

Photograph Direction: Southeast 

 

 PM10 PM2.5 Continuous 

Spatial scale Middle Middle 

Monitoring objective Population exposure Population exposure 

Vertical probe placement 4.8 m 4.9 m 

Unrestricted airflow 360° 360° 

Spacing from trees 4.8 m 2.2 m 

Spacing from station to road 12.2 m 12.2 m 

Distance between collocated monitors 2.5 m 2.5 m 

Ground cover Paved, gravel Paved, gravel 

Spacing from supporting structure — — 
32 

 PM10 PM2.5 Continuous 

Obstructions on roof — — 

Obstacle distance 7.1 m 6.6 m 

PM Probe material Stainless steel Stainless steel 

Residence time — — 
33 

Figure 7 – J.D. Smith 

Type: NAMS/SLAMS 

J.D. Smith (JD) (32-003-2002) 

Location: 1301B Tonopah Ave., North Las Vegas, NV 89030 

Three Closest Roads: E. Owens Ave., N. Bruce St., E. Lake Mead Blvd. 

UTM X-Coordinate: 668778.300; UTM Y-Coordinate: 4006793.000 

Operative Schedule: 24 hours 

Sampling Method: Ozone: Ultraviolet Absorption, API 400A 

Carbon Monoxide: Gas Filter Correlation Analyzer, API 300E 

PM10: Beta Attenuation, Thermo Electron FH 62 C14 

PM2.5: Beta Attenuation, Thermo Electron FH 62 C14 

PM2.5: Andersen RAAS2.5-300 FRM 

Nitrogen Dioxide: Gas Phase Chemiluminescence, API 200E 

Predominant Wind Direction: Southwest 

Photograph Direction: North 

 PM10 CO PM2.5 (FRM) NO2 O3

PM2.5

Continuous 

Spatial scale Neighborhood 

Neighborhood Neighborhood Neighborhood Neighborhood Neighborhood 

Monitoring objective Population 

exposure 

Population 

exposure 

Population 

exposure 

Population 

exposure 

Population 

exposure 

Population 

exposure 

Vertical probe placement 4.7 m 3.7 m 3.6 m 3.7 m 3.7 m 4.8 m 

Unrestricted airflow 360° 360° 360° 360° 360° 360° 
34 

 PM10 CO PM2.5 (FRM) NO2 O3

PM2.5

Continuous 

Spacing from trees 35 m 32.8 m 35 m 32.8 m 32.8 m 35 m 

Spacing from station to 

road 135 m 135 m 141 m 135 m 135 m 135 m 

Distance between collocated monitors 2.6 m — NA — — 2.6 m 

Ground cover Paved, grass — Paved, grass — — Paved, grass 

Spacing from supporting 

structure — 1.2 m — 1.2 m 1.2 m — 

Obstructions on roof None — None — — None 

Obstacle distance 3.3 m to wall — 5.1 m to wall 4.2 m to wall 4.2 m to wall 5.9 m to wall 

Probe material — — — Teflon Teflon — 

Residence time — 5.3 s — 5.3 s 5.3 s — 
35 

Figure 8 – Jean 

Type: SLAMS 

Jean (JN) (32-003-1019) 

Location: 1965 State Highway 161, Jean, NV 89019 

Roads: State Highway 161, I-15 

UTM X-Coordinate: 648490.100; UTM Y-Coordinate: 3961425.000 

Operative Schedule: 24 hours 

Sampling Method: Ozone: Ultraviolet Absorption, API 400E 

PM10: Beta Attenuation, Thermo Electron FH 62 C14 

PM2.5: Beta Attenuation, Thermo Electron FH 62 C14 

PM2.5: Andersen RAAS2.5-300 FRM 

Predominant Wind Direction: Southwest 

Photograph Direction: Southwest 

 PM10

PM2.5

Continuous O3 PM2.5 (FRM) 

Spatial scale Regional Regional Regional Regional 

Monitoring objective Background Background Transport Background 

Vertical probe placement 4.8 m 4.8 m 4 m 2.1 m 

Unrestricted airflow 360° 360° 360° 360° 

Spacing from trees — — — — 

Spacing from station to 

road 1,287 m 1,287 m 1,287 m 1,287 m 

Distance between 

collocated monitors 2.7 m 2.7 m — 10 m 

Ground cover Native desert, gravel Native desert, gravel — Native desert, gravel 
36 

 PM10

PM2.5

Continuous O3 PM2.5 (FRM) 

Spacing from supporting structure — — 1.4 m — 

Obstructions on roof — — — — 

Obstacle distance — — — — 

Probe material — — Teflon — 

Residence time — — 1.6 s — 
37 

Figure 9 – Joe Neal 

Type: SLAMS 

Joe Neal (JO) (32-003-0075) 

Location: 6651 W. Azure Way, Las Vegas, NV 89130 

Three Closest Roads: Ann Rd., N. Tenaya Way, W. Azure Way 

UTM X-Coordinate: 658246.700; UTM Y-Coordinate: 4015402.000 

Operative Schedule: 24 hours 

Sampling Method: Ozone: Ultraviolet Absorption, API 400A 

PM10: Beta Attenuation, Thermo Electron FH 62 C14 

Nitrogen Dioxide: Gas Phase Chemiluminescence, API 200E 

Predominant Wind Direction: Northwest 

Photograph Direction: North 

 PM10 O3 NO2

Spatial scale Neighborhood Neighborhood Neighborhood 

Monitoring objective Population exposure Highest concentration Population exposure 

Vertical probe placement 4.7 m 3.8 m 3.8 m 

Unrestricted airflow 360° 360° 360° 

Spacing from trees 8.2 m 5.7 m 5.7 m 

Spacing from station to road 12.6 m 12.6 m 12.6 m 

Distance between collocated 

monitors — — — 

Ground cover Gravel, grass, natural desert — — 

Spacing from supporting 

structure — 0.5 m 2.62 m 

Obstructions on roof None — — 

Obstacle distance None None None 

Probe material — Teflon Teflon 

Residence time — 2.1 s 2.1 s 
38 

Figure 10 – Lone Mountain 

Type: SLAMS 

Lone Mountain (LM) (32-003-0072) 

Location: 3525 N. Valadez St., Las Vegas NV 89129 

Three Closest Roads: N. Cimarron Rd., W. Gowan Rd., N. Buffalo Dr. 

UTM X-Coordinate: 655656.400; UTM Y-Coordinate: 4010319.000 

Operative Schedule: 24 hours 

Sampling Method: Ozone: Ultraviolet Absorption, API 400 

PM10: Beta Attenuation, Thermo Electron FH 62 C14 

Predominant Wind Direction: Northwest 

Photograph Direction: West 

 PM10 O3

Spatial scale Neighborhood Neighborhood 

Monitoring objective Population exposure Population exposure 

Vertical probe placement 4.9 m 4.4 m 

Unrestricted airflow 360° 360° 

Spacing from trees 9.0 m 12.1 m 

Spacing from station to road 50.0 m 50.0 m 

Distance between collocated monitors None — 

Ground cover Gravel — 

Spacing from supporting structure — 0.5 m 

Obstructions on roof None — 

Obstacle distance 18.0 m 15.5 m 

Probe material — Teflon 

Residence time — 10.7 s 
39 

Figure 11 – Mesquite 

Type: SLAMS 

Mesquite (MQ) (32-003-0023) 

Location: 465 E. Old Mill Rd., Mesquite, NV 89027 

Three Closest Roads: I-15, N. Sandhill Blvd., Old Mill Rd. 

UTM X-Coordinate: 762202.400; UTM Y-Coordinate: 4077598.000 

Operative Schedule: 24 hours 

Sampling Method: Ozone: Ultraviolet Absorption, API 400A 

PM10: Beta Attenuation, Thermo Electron FH 62 C14 

Predominant Wind Direction: Southwest 

Photograph Direction: West 

 PM10 O3

Spatial scale Middle Neighborhood 

Monitoring objective Population exposure Population exposure 

Vertical probe placement 4.7 m 3.6 m 

Unrestricted airflow 360° 360° 

Spacing from trees 24 m 24.0 m 

Spacing from station to road 5.9 m 7.7 m 

Distance between collocated monitors — — 

Ground cover Adjacent raised dirt field — 

Spacing from supporting structure — 0.5 m 

Obstructions on roof None — 

Obstacle distance None None 
40 

 PM10 O3

Probe material — Teflon 

Residence time — 10.3 s 
41 

Figure 12 – Orr 

Type: SLAMS 

Orr (OR) (32-003-1021) 

Location: 1562D E. Katie Ave., Las Vegas, NV 89119 

Three Closest Roads: E. Katie Ave., S. Maryland Pkwy., E. Flamingo Rd. 

UTM X-Coordinate: 667832.143; UTM Y-Coordinate: 3998918.690 

Operative Schedule: 24 hours 

Sampling Method: Carbon Monoxide: Gas Filter Correlation CO Analyzer, API 300E 

Ozone: Ultraviolet Absorption, API 400E 

PM10: Beta Attenuation, Thermo Electron FH 62 C14 

Predominant Wind Direction: Southwest 

Photograph Direction: Northwest 

 PM10 CO O3

Spatial scale Middle Neighborhood Neighborhood 

Monitoring objective Population exposure Population exposure Population exposure 

Vertical probe placement 4.6 m 4.4 m 4.4 m 

Unrestricted airflow 360° 360° 360° 

Spacing from trees 30.0 m 28.0 m 28.0 m 

Spacing from station to road 11.2 m 11.2 m 11.2 m 

Distance between collocated monitors — — — 

Ground cover Paved, grass, gravel — — 

Spacing from supporting structure — — 0.5 m 

Obstructions on roof None — — 
42 

 PM10 CO O3

Obstacle distance No obstacles — — 

Probe material — — Teflon 

Residence time — — 3.5 s 
43 

Figure 13 – Palo Verde 

Type: SLAMS 

Palo Verde (PV) (32-003-0073) 

Location: 333 Pavilion Center Dr., Las Vegas, NV 89144 

Three Closest Roads: W. Alta Dr., S. Town Center Dr., W. Charleston Blvd. 

UTM X-Coordinate: 649914.700; UTM Y-Coordinate: 4004542.000 

Operative Schedule: 24 hours 

Sampling Method: Ozone: Ultraviolet Absorption, API 400E 

PM2PM10: Beta Attenuation, Thermo Electron FH 62 C14 

Predominant Wind Direction: Southwest 

Photograph Direction: East 

 PM10 O3 

Spatial scale Middle Neighborhood 

Monitoring objective Population exposure Population exposure 

Vertical probe placement 4.9 m 3.7 m 

Unrestricted airflow 360° 360° 

Spacing from trees 16.7 m 19.9 m 

Spacing from station to road 14.7 m 14.7 m 

Distance between collocated monitors NA — 

Ground cover Paved Paved 

Spacing from supporting structure — 0.5 m 

Obstructions on roof — — 

Obstacle distance — — 
44 

 PM10 O3 

Probe material — Teflon 

Residence time — 2.1 s 
45 

Figure 14 – Paul Meyer 

Type: SLAMS 

Paul Meyer (PM) (32-002-0043) 

Location: 4525 New Forest Dr., Las Vegas, NV 89147 

Three Closest Roads: S. Rainbow Blvd., W. Tropicana Ave., S. Buffalo Dr. 

UTM X-Coordinate: 657221.200; UTM Y-Coordinate: 3997162.000 

Operative Schedule: 24 hours 

Sampling Method: Ozone: Ultraviolet Absorption, API 400A 

PM10: Beta Attenuation, Thermo Electron FH 62 C14 

Predominant Wind Direction: South 

Photograph Direction: Southwest 

 PM10 O3

Spatial scale Neighborhood Neighborhood 

Monitoring objective Population exposure Population exposure 

Vertical probe placement 6.3 m 4.0 m 

Unrestricted airflow 360° 360° 

Spacing from trees 17.1 m 21 m 

Spacing from station to road 102.0 m 102.0 m 

Distance between collocated monitors — — 

Ground cover Paved, grass, concrete — 

Spacing from supporting structure — 0.6 m 

Obstructions on roof None — 

Obstacle distance None — 

Probe material — Teflon 

Residence time — 2.93 s 
46 

Figure 16 – Sunrise Acres 

Type: SLAMS 

Sunrise Acres (SA) (32-003-0561) 

Location: 2501 Sunrise Ave., Las Vegas, NV 89101 

Three Closest Roads: N. Eastern Ave., Sunrise Ave., N. 26th St. 

UTM X-Coordinate: 669664.653; UTM Y-Coordinate: 4003698.329 

Operative Schedule: 24 hours 

Sampling Method: Carbon Monoxide: Gas Filter Correlation, API 300E 

PM10: Beta Attenuation, Thermo Andersen FH 62 C14 

PM2.5: Beta Attenuation, Thermo Electron FH 62 C14 

PM2.5: Andersen RAAS2.5-300 FRM 

PM2.5 Collocated: Andersen RAAS2.5-300 FRM 

Predominant Wind Direction: South 

Photograph Direction: Northeast 

 PM10 CO PM2.5 (FRM) PM2.5 FRM 

Collocated 

PM2.5

Continuous 

Spatial scale Neighborhood Neighborhood Neighborhood Neighborhood Neighborhood 

Monitoring objective Population. 

exposure 

Highest 

concentration 

Highest 

concentration 

Highest 

concentration 

Highest 

concentration 

Population exposure Highest 

concentration — — — — 

Vertical probe placement 4.7 m 3.6 m 2.9 m 2.9 m 4.8 m 

Unrestricted airflow 360° 360° 360° — 360° 

Spacing from trees — — — — — 
47 

 PM10 CO PM2.5 (FRM) PM2.5 FRM 

Collocated 

PM2.5

Continuous 

Spacing from station to 

road 134 m 134 m 134 m 134 m 134 m 

Distance between collocated monitors 3.0 m — 2.1 m 2.1 m 3.0 m 

Paving Ground cover — Paved Paved Paved 

Spacing from supporting 

structure — — — — — 

Obstructions on roof None — — — None 

Obstacle distance — — 8 m to wall 7 m to wall — 

3.99 building height 6.5 m to building — — — — 

Probe material — Teflon — — — 

Residence time — 0.54 s — — — 
48 

Figure 17 – Walter Johnson 

Type: SLAMS 

Walter Johnson (WJ) (32-002-0071) 

Location: 7701 Ducharme Ave., Las Vegas, NV 89145 

Three Closest Roads: S. Buffalo Dr., Alta Dr., S. Cimarron Rd. 

UTM X-Coordinate: 656223.000; UTM Y-Coordinate: 4004175.000 

Operative Schedule: 24 hours 

Sampling Method: Ozone: Ultraviolet Absorption, API 400 

Predominant Wind Direction: Southwest 

Photograph Direction: West 

O3

Spatial scale Neighborhood 

Monitoring objective Population exposure 

Vertical probe placement 3.7 m 

Unrestricted airflow 360° 

Spacing from trees 16.5 m 

Spacing from station to road 13.0 m 

Distance between collocated monitors — 

Ground cover — 

Spacing from supporting structure 0.5 m 

Obstructions on roof — 

Obstacle distance 18.4 m 

Probe material Teflon 

Residence time 3.1 s 
49 

Figure 18 – Winterwood 

Type: NAMS/SLAMS 

Winterwood (WW) (32-0030-538), Elevation 1788 

Location: 5483 Club House Dr., Las Vegas, NV 89142 

Three Closest Roads: E. Sahara Ave., Winterwood Blvd., S. Nellis Blvd. 

UTM X-Coordinate: 674872.900; UTM Y-Coordinate: 4001556.000 

Operative Schedule: 24 hours 

Sampling Method: Ozone: Ultraviolet Absorption, API 400A 

Carbon Monoxide: Gas Filter Correlation Analyzer, API 300E 

Predominant Wind Direction: Southeast 

Photograph Direction: North 

CO O3

Spatial scale Neighborhood Neighborhood 

Monitoring objective Population exposure Population exposure 

Vertical probe placement 3.9 m 3.9 m 

Unrestricted airflow 360° 360° 

Spacing from trees 26.4 m 26.4 m 

Spacing from station to road 42 m 42 m 

Distance between collocated monitors — — 

Ground cover Paving, grass, rock — 

Spacing from supporting structure 0.5 m 0.5 m 

Obstructions on roof — — 

Obstacle distance — — 

Probe material — Teflon 

Residence time — 3.1 s 
50 

Figure 19 – Visibility Sites 

Visibility Monitoring Network (Transmitter/Receiver) 

VISIBILITY SITE (Las Vegas) 

Bank of America – T1 receiver 

Location: 300 S. Fourth St., Las Vegas, NV 89101 

Three closest roads: Fremont St., S. Las Vegas Blvd., Main St. 

Operative Schedule: 24 hours 

Equipment: Optec LPV-2 

VISIBILITY SITE (Las Vegas) 

Sunrise Hospital – T1 transmitter 

Location: 3186 S. Maryland Pkwy., Las Vegas, NV 89109 

Three Closest Roads: E. Desert Inn Rd., Vegas Valley Dr., Maryland Pkwy. 

Operative Schedule: 24 hours 

Equipment: Optec LPV-2 
51 

Carbon Monoxide Monitoring Locations 

Figure 20 – Carbon Monoxide Monitoring Locations 
52 

Ozone Monitoring Locations 

Figure 21 – Ozone Monitoring Locations in Las Vegas, Boulder City, and Apex 
53 

Figure 22 – Ozone Monitoring Location in Jean 
54 

Figure 23 – Ozone Monitoring Location in Mesquite 
55 

Nitrogen Oxide Monitoring Locations 

Figure 24 – Nitrogen Oxide Monitoring Locations in Las Vegas 
56 

Continuous PM10 Monitoring Locations 

Figure 25 – Continuous PM10 Monitoring Locations in Las Vegas, Boulder City, and Apex 
57 

Figure 26 – Continuous PM10 Monitoring Location in Jean 
58 

Figure 27 – Continuous PM10 Monitoring Location in Mesquite 
59 

Continuous PM2.5 Monitoring Locations 

Figure 28 – Continuous PM2.5 Monitoring Locations in Las Vegas and Apex 
60 

Figure 29 – Continuous PM2.5 Monitoring Location in Jean 
61 

Filter-Based PM2.5 Monitoring Locations 

Figure 30 – Filter-Based PM2.5 Monitoring Locations in Las Vegas 
62 

Figure 31 – Filter Based PM2.5 Monitoring Location in Jean 
63 

Effect of New Regulations on Air Monitoring 

On February 9, 2010, EPA released 40 CFR Parts 50 and 58, “Primary National Ambient Air 

Quality Standards for Nitrogen Dioxide; Final Rule.” In this revision, EPA established requirements for an NO2 monitoring network with monitors at locations where maximum NO2 concentrations are expected to occur, including within 50 meters of major roadways, and monitors sited 

to measure the area-wide NO2 concentrations that occur more broadly across communities. Clark 

County is currently investigating siting locations and believes that the City Center site (EPA site 

number 32-003-0016) may meet this requirement. City Center is one of the top ten high traffic 

count areas. It has a diverse traffic mix that includes older vehicles, since it is located in an underserved community, and experiences significant congestion at least twice per day. City Center 

is situated in a unique topographic area that, based on predominant wind flow, receives transport 

from both the I-15 and South Las Vegas Boulevard (i.e., Las Vegas Strip) corridors, as well as 

roadside emissions from U.S. Highway 95; since the site is within 50 m of U.S. 95, it may also 

be suitable for microscale monitoring. In addition, the City Center location has the flexibility to 

qualify for neighborhood scale monitoring. A previous study determined that ozone was undergoing titration by NOx from vehicles on U.S. 95. 

On November 12, 2008, EPA released the revised NAAQS for lead (Pb). There are two lead 

monitoring requirements that Clark County must address: ambient nonsource monitoring and 

ambient source-oriented monitoring. DAQEM plans to initiate ambient nonsource lead monitoring at the NCore site by January 2011. DAQEM is currently in the process of identifying potential sources that may trigger required ambient source-oriented lead monitoring. 

DAQEM is planning for an NCore site in accordance with 40 CFR 58, Appendix D. The location 

is a new monitoring station at Jerome Mack Middle School that should be operating by January 

2011. 

With the exception of PM2.5 FRM samplers, pollen samplers, speciation samplers, and nonroutine special studies, all monitoring instruments are operated continuously all year round. 
64 

Summary of Monitoring Requirements 

40 CFR 58 dictates requirements for maintaining ambient air monitoring networks. DAQEM 

continuously considers those requirements in its network design, resulting in the conclusions 

listed beneath each requirement. 

1. Determine the highest NAAQS concentration area in the network. 

 The area of highest CO concentration is the Sunrise Acres station at 2501 Sunrise 

Ave., Las Vegas, NV. 

 The areas of highest O3 concentration are the Joe Neal station at 6651 W. Azure Way, 

Las Vegas, NV and the Walter Johnson station at 7701 Ducharme Ave., Las Vegas, 

NV. 

 The area of highest PM10 concentration is the Apex station at 12101 U.S. Highway 

93, Las Vegas, NV. 

 The area of highest annual average PM2.5 concentration is the Sunrise Acres station at 

2501 Sunrise Ave. 

 The area of highest annual average NO2 concentration is the J.D. Smith station at 

1301b E. Tonopah Dr. 

2. Determine representative concentrations in areas of high population density. 

 City of Las Vegas: 

- Annual average CO concentration is 0.6 ppm. 

- Annual average O3 concentration is 0.031 ppm. 

- Annual average PM10 concentration is 21.9 g/m3

. 

- Average PM2.5 concentration is 8.64 g/m3. 

- Annual average NO2 concentration is 0.011 ppm. 

 City of Henderson: 

- Annual average PM10 concentration is 19.86 g/m3

. 

- Average PM2.5 concentration is 6.65 g/m3

. 

 City of Boulder City: 

- Annual average O3 concentration is 0.045 ppm. 

- Annual average PM10 concentration is 14.55 g/m3. 

 City of Mesquite: 

- Annual average O3 concentration is 0.028 ppm. 

- Annual average PM10 concentration is 20.45 g/m3

. 

3. Determine impacts of significant sources on air quality. 

 CO sources: vehicle and non-vehicle combustion sources 

- Impact: zero exceedance days. 

 NO2 sources: vehicle and non-vehicle combustion sources 

- Impact: zero exceedance days. 

 PM2.5 sources: vehicle and non-vehicle combustion sources, fugitive dust 

- Impact: zero exceedance days. 

 PM10 sources: fugitive dust, industrial processes 

- Impact: One exceedance day in 2009. 
65 

4. Determine general background concentration levels. 

 Jean: 

- PM10: 2009 average = 12.37 g/m3. 

- PM2.5: 2009 average = 4.85 g/m3

. 

- O3: 2009 average = 0.041 ppm. 

5. Determine extent of regional pollutant transport among population areas. 

 Studies show that ozone transport and regional contributors have an influence on 

Clark County, which results in ozone exceedances. Smoke from seasonal wildfires 

contributes significantly to ozone and particulate matter levels in Clark County. 

6. Determine welfare-related impacts in rural and remote areas. 

 Monitoring at Jean serves a rural area, provides background levels, and can be used to 

indicate transport from California 

 Monitoring at Boulder City serves a rural population 

 Monitoring at Mesquite serves a remote population and is located at an outflow transport corridor adjacent a jurisdictional boundary 

Clark County Air Monitoring Network 

The table below shows that the network meets or exceeds the minimum monitoring requirements 

in 40 CFR 58. 

Pollutant Monitors Required Monitors in service in 2009

CO 0 5 

O3 2 13 

SO2 0 0 

NO2 0 2 

PM10 BAM 4-8 13 

PM2.5 BAM 0 6 

PM2.5 FRM 2 + collocation 3 + collocation 

DAQEM uses the following criteria to evaluate the placement and function of the network to 

meet the requirements of 40 CFR 58: 

1. Monitoring objectives 

2. AQS scale of representation 

3. Emission densities 

4. Dispersion modeling 

5. Special studies 

6. Revised monitoring strategies 

7. Sampling schedules 

8. Las Vegas area population. 
66 

State implementation and maintenance plans require no additional instrumentation. 
67 

Quality Assurance Program 

The QA Officer conducted performance field evaluations throughout 2009. These audits indicated that DAQEM is providing instrument data of sufficient quality to satisfy EPA guidance parameters and meet Measurement Quality Objectives. 

All gaseous criteria pollutant monitoring instruments were field-audited. There were no SO2 instruments to be audited. Two sites had NO2 instruments, and both were evaluated. Five CO instruments were evaluated. Twelve O3 instruments were also audited, and there were no failures. 

Seven PM2.5 FRM RAAS samplers at three monitoring sites were evaluated. A single SASS was 

audited. Twelve continuous PM10 C-14 BAMs and six continuous PM2.5 C-14 BAMs underwent 

performance evaluations for flow, temperature, pressure, and time. Each continuous PM2.5 BAM 

is equipped with a Very Sharp Cut Cyclone as a second stage separator. The PM2.5 FRM samplers are equipped with a mix of Very Sharp Cut Cyclone separators and Well Impactor NinetySix impactors. The three PM2.5 FRM sites (including Sunrise Acres, which hosts the precision 

pair) were evaluated twelve times during 2009. Each operational PM2.5 FRM and the SASS were 

audited quarterly. All continuous particulate monitors were evaluated semiannually except the 

one at the Boulder City site, where sampling was terminated for site structure repair. 

Evaluations of audit sites were balanced across the calendar year. Any adjustments to the auditing schedule favored pollutant seasonality, e.g., more CO instruments were audited during the 

winter months and more ozone instruments during the summer months. Audit evaluations of the 

gaseous pollutants used the transmutation values of slope/intercept created by calibration activity 

from the IPS MeteoStar Leading Environment Analysis and Display System, DAQEM’s data acquisition system. Assessments of data flow—from collection, to storage, to transfer, to 

processing with verification, to validation, to review and submittal—indicated consistent, thorough, and acceptable handling regimens. 

Precision and accuracy data were uploaded to the AQS database in accordance with 40 CFR 58 

requirements, and annual data certifications were completed in accordance with 40 CFR 58.15 

requirements. 

The following table summarizes the 2009 gaseous and continuous particulate matter event schedule for internal QA performance evaluations. 

 

Date Pollutant Monitoring Stations

2/26/2009 PM10 Jean 

3/12/2009 PM10 Paul Meyer 

3/19/2009 PM10 Lone Mountain 

3/31/2009 PM10 Joe Neal 

5/6/2009 PM10 Apex, E. Craig Road 

5/13/2009 PM10 Sunrise Acres 

7/31/2009 PM10 Boulder City 

8/28/2009 PM10 Joe Neal, Lone Mountain, Paul Meyer 

8/31/2009 PM10 J.D. Smith, Mesquite 
68 

Date Pollutant Monitoring Stations

9/10/2009 PM10 Green Valley, Orr 

9/11/2009 PM10 Jean 

12/03/2009 PM10 Craig Road, Orr, Sunrise Acres 

12/04/2009 PM10 Apex, Green Valley, J.D. Smith 

12/24/2009 PM10 Mesquite 

2/26/2009 PM2.5 Jean 

5/6/2009 PM2.5 Apex, E. Craig Road 

5/13/2009 PM2.5 Sunrise Acres 

8/31/2009 PM2.5 J.D. Smith 

9/10/2009 PM2.5 Green Valley 

9/11/2009 PM2.5 Jean 

12/03/2009 PM2.5 E. Craig Road, Sunrise Acres 

12/04/2009 PM2.5 Apex, Green Valley, J.D. Smith 

1/27/2009 RAAS Sunrise Acres 

2/19/2009 RAAS J.D. Smith 

3/27/2009 RAAS Jean 

7/21/2009 RAAS J.D. Smith, Sunrise Acres 

9/11/2009 RAAS Jean 

12/28/2009 RAAS Jean, J.D. Smith, Sunrise Acres 

3/27/2009 CO E. Sahara, Winterwood 

5/13/2009 CO Winterwood 

12/22/2009 CO Orr 

12/31/2009 CO J.D. Smith 

3/12/2009 O3 Paul Meyer 

3/13/2009 O3 Walter Johnson 

3/19/2009 O3 Lone Mountain 

3/25/2009 O3 Jean 

3/26/2009 O3 Palo Verde 

7/30/2009 O3 Apex 

7/31/2009 O3 Boulder City 

9/10/2009 O3 Orr 

12/23/2009 O3 E. Craig Road, J.D. Smith 

12/24/2009 O3 Mesquite 

3/31/2009 NO2 Joe Neal 

12/31/2009 NO2 J.D. Smith 
69 

Speciation sampling is grant-funded, and DAQEM operates as an informational adjunct to the 

ambient sampling network. Because it does not have a dedicated sampling site in the Chemical 

Speciation Network, DAQEM can move the speciation samplers throughout the county to support special project initiatives. In 2009, all sampling events took place at the E. Craig Road site; 

performance evaluations were conducted on 1/27/2009, 5/6/2009, 9/11/2009, and 12/08/2009. 
70 

National Performance Audits 

DAQEM is available for participation in the EPA Region 9-sponsored National Performance 

Evaluation Program. This Through-The-Probe (TTP) performance evaluation, which focuses on 

gaseous criteria pollutants, is contracted for and scheduled by Region 9. Audit results are made 

available immediately. DAQEM received a “Pass” audit report for all TTP performance evaluations in 2009. 

The following table shows the 2009 TTP event schedule. 

MONITORING STATION POLLUTANT TTP CONDUCTED 

Walter Johnson O3 4/13/2009 

Orr, Winterwood CO, O3 4/14/2009 

J.D. Smith CO, O3, NO2 4/15/2009 

Sunrise Acres CO 4/16/2009 

DAQEM annually submits its PM2.5 FRM sampling network for a Performance Evaluation Program (PEP) audit. Through EPA Region 9, an independent auditor is contracted to perform external field audits. An audit event occurs quarterly at the same specified site. The contractor 

submits evaluation results to the AQS database. Because of the manual methods used to audit 

FRM samplers, the audit findings (in μg/m3) are not immediately known. 

The following table summarizes 2009 PEP audit event activity. 

PM2.5 Sampler Location Date of PEP Audit 

J.D. Smith 1/07/2009 

J.D. Smith 5/13/09 

J.D. Smith 8/11/2009 

J.D. Smith 11/03/2009 
71 

Network Modifications Completed in 2009 

The following table summarizes network changes in 2009. 

Action Date Reason 

Terminated chemiluminescent 

O3 operations at Joe Neal site September 2009 Operated as part of 2009 wildfire study; instrument 

ran between April and September 

Temporarily shut down O3 and 

PM10 operations at Boulder City 

site. 

November 2009 Station repairs 
72 

Network Modifications Proposed

This section describes anticipated and potential changes to the air monitoring network over the 

next two years. The actions proposed in this section constitute DAQEM’s official approval request to EPA Region 9. 

 

Financial, technical, and regulatory challenges may necessitate air monitoring site and equipment 

terminations. In addition, logistical issues, such as expired leases, leases due to expire, and administrative issues may require DAQEM to terminate sites or equipment beyond what is specified in this plan. 

Proposed Terminations 

Site/Equipment Termination Date Explanation 

Apex To be determined Site is located on property of a major stationary 

source 

PM2.5 FRMs at J.D. Smith and Jean 

sites To be determined 

Anticipate continuous PM2.5 FEM or ARM deployment at NCore site; Sunrise Acres has the 

primary and collocated PM2.5 FRM for the network 

CO monitoring at J.D. Smith, Orr, E. 

Sahara, and Winterwood sites To be determined No EPA requirement for CO monitoring 

O3 monitoring at Orr, Winterwood, 

Boulder City, Walter Johnson, and 

Lone Mountain sites 

To be determined EPA requires only two sites for O3 monitoring 

E. Craig Road, Mesquite, Apex, Jean, 

and Lone Mountain sites To be determined Unresolved lease issues 

Additional Site Closures To be determined Site Closures due to budgetary issues 

Note: ARM = Approved Regional Method. 

Termination Considerations 

Apex. The Apex site is located on the property of a major stationary source. Data trends indicate 

that the major source may be influencing this site, so DAQEM has reconsidered its viability. The 

site may be reconfigured for meteorological measurements, including upper air measurements. 

PM2.5 FRM samplers at J.D. Smith and Jean sites. In 2009, DAQEM maintained operations in 

the PM2.5 FRM filter-based network to match the grant level of funding. If this network is reduced, DAQEM will continue to keep using, and applying for, grant funding based on activities 

outside the PM2.5 FRM network, including PM2.5 BAM operations, PM2.5 speciation sampling, 

PM2.5 FEM and ARM efforts, applicable NCore monitoring, and related training. If deemed appropriate, the criteria in 40 CFR 58.14(c)(3) will comprise DAQEM’s justification for discontinuing filter-based PM2.5 FRM samplers altogether. DAQEM is anticipating the upgrade of a 

PM2.5 BAM to FEM status and a potential ARM designation in 2010. Sunrise Acres has the primary and collocated PM2.5 FRM sampler for the network, and DAQEM anticipates installing a 

PM2.5 BAM at the NCore site that may receive FEM or ARM designation. 
73 

CO monitoring at J.D. Smith, Orr, East Sahara, and Winterwood sites. Since 40 CFR 

58.14(c)(2) no longer requires CO monitoring at these locations, DAQEM may discontinue use 

of these monitors. DAQEM will evaluate the CO data from these sites and the state implementation plan (SIP) requirements, and may choose to terminate CO monitoring at these sites to conserve resources that can be redirected within the monitoring program. 

O3 monitoring at Orr, Winterwood, Boulder City, Walter Johnson, and Lone Mountain 

sites. In accordance with 40 CFR 58, DAQEM is only required to operate two O3 monitoring 

sites. DAQEM will evaluate the O3 data from these sites and the SIP requirements, and may 

choose to terminate O3 monitoring at these sites to conserve resources that can be redirected 

within the monitoring program. Comparatively, Orr and Winterwood sites measure lower O3

readings in the Las Vegas Valley, and Boulder City has the potential to be considered nonrepresentative. The Walter Johnson and Lone Mountain sites could be considered redundant; 

however, both have been the high O3 site in the network. DAQEM will continue to monitor and 

evaluate O3 in the urban core, high-concentration areas, background areas, and other areas to 

characterize transport. 

E. Craig Road, Mesquite, Apex, Jean, and Lone Mountain sites. These sites have a variety of 

issues with lease or occupancy agreements. DAQEM could be required to vacate with little or no 

notice, which would necessitate terminating all monitoring operations. 

Additional Site Closures. Due to reductions in the Air Quality Monitoring budget, DAQEM is 

considering site closures during the 2010 calendar year. 

Proposed Relocations and Installations 

Relocation/Installation Date Explanation 

E. Sahara 2010 Remove monitoring equipment from private property; begin 

monitoring at nearby Jerome Mack Middle School 

E. Craig Road 2010 Move SASS and URG from E. Craig Road to Jerome Mack 

Middle School to support NCore operations 

Apex 2011 Install SODAR to provide upper air data, facilitate O3 forecasting & transport 

Note: SODAR = sonic detection and ranging. 

Relocation and Installation Considerations 

East Sahara. This site has several administrative and logistical issues: (1) zoning requires the site 

to be a wheeled mobile unit; (2) the structure is past its life expectancy; (3) climate control indoors has become increasingly difficult; (4) electrical code prohibits permanent use of extension 

cords, which are the only way to power this unit; (5) electricity prices at this location have increased significantly; and (6) the lease requires all tenants to share the cost of electric usage, 

which causes monthly fees to vary considerably. DAQEM will relocate operations to the Jerome 

Mack Middle School NCore Site in 2010, less than a mile away. 
74 

East Craig Road. Speciation sampling at this site will be moved to the Jerome Mack Middle 

School NCore monitoring station before January 2011; the move will include both the SASS and 

URG samplers. 

Apex. DAQEM plans to install a SODAR unit at the Apex monitoring station. The unit will provide upper-air meteorological data, facilitate pollution forecasting, characterize outflow from the 

Las Vegas Valley, and help in evaluating pollution transport issues. 

Other Considerations 

Ivanpah Valley. DAQEM is conducting background monitoring at the Jean site in the Ivanpah 

Valley. Since there may be construction in this area over the next few years, the Jean site may 

continue to monitor PM10, PM2.5, other criteria pollutants, and meteorological parameters. 

Spatial monitoring gaps and potential high pollutant sites. DAQEM has an interest in filling spatial monitoring gaps and monitoring in high concentration areas. Through special studies, modeling, and forecasting, DAQEM has projected spatial gaps and elevated pollutant concentrations in 

specific areas throughout the county: Indian Springs, Laughlin, Coyote Springs, the north-central 

valley, the southwest valley, and Mt. Charleston have been identified for potential monitoring in 

the future when resources allow. 

Collaboration on monitoring. DAQEM may receive opportunities to exchange information and 

data with other local agencies, such as the Desert Research Institute (DRI) and the Las Vegas 

Paiute Tribe. DAQEM may also seek opportunities to enhance current data sets through data exchanges, and may engage in operational exchanges while ensuring the integrity of associated data. 

Mobile monitoring. DAQEM would like to implement a mobile monitoring system as an evaluation tool for PM10 and O3 throughout Clark County. The mobile monitoring system could be deployed at various locations to assess air quality and help determine where to site permanent 

monitoring stations. DAQEM’s current resource limitations do not allow its to implement a mobile monitoring system at this time, but the department will continue to look for opportunities to 

fund this project. 

In addition to the modifications proposed above, DAQEM will evaluate other network changes 

based on results from the following studies: 

1. “PM10 Saturation Study” (completed December 2005). 

2. “Clark County Regional Ozone & Precursor Study” (completed March 2006). 

3. ”Field Measurements and Documentation of Wildfire Event Air Quality Impacts during 

the 2009 Summer Wildfire Season.” 

4. Analysis to determine the ozone nonattainment boundary area (completed July 2004). 

5. “Carbon Monoxide Saturation Study” (completed April 2002), which confirmed at the 

time that the network did not miss any CO hot spots. (DAQEM is currently reevaluating 

the CO network and considering site closures.) 
75 

6. The recent designation by EPA of the Thermo Electron FH 62 C14 PM2.5 BAM as an 

FEM, or the potential EPA approval of the Thermo Electron FH 62 C14 PM2.5 BAM as 

an ARM. 
76 

Status of Monitoring Site Leases 

The following table documents the status of leases for each monitoring site as of March 2009. 

Expired leases or related events may result in the closure of a monitoring station at a particular 

site. This plan constitutes DAQEM’s official request to EPA Region 9 to discontinue monitoring 

under these or similar circumstances. 

Site Documentation Owner Terms Status of Negotiations

Apex 

Agreement with 

BLM. However, 

property is not 

owned by BLM. 

Site is part of 

property owned 

and operated by 

Chemical Lime. 

Chemical Lime 9/17/20 Complete 

Boulder City: 

1 pollen site, 1 air quality 

monitoring station (at different locations) 

2 agreements City of Boulder 

City 11/30/15 Complete 

City Center Space use 

permit NDOT Expired 

E. Craig Road None L&M Holding 

County letter to 

property owner 

identifying presence of trailer on 

site 

Complete (owner unwilling to provide authorization) 

E. Sahara Lease Maycliff 

Storage 6/30/12 Site being relocated to Jerome 

Mack Middle School 

Green Valley Agreement City of 

Henderson Ended 3/15/96 Agreement held by Henderson City 

Attorney 

J.D. Smith MOU Clark County 

School District 5/10/10 Currently in renewal process 

Jean 

ROW grant/ 

temp. use 

permit 

BLM 6/22/09 Complete (owner unwilling to provide authorization renewal) 

Joe Neal MOU Clark County 

School District 5/10/10 Currently in renewal process 

Lone Mountain No agreement LV Water 

District 

New interlocal 

agreement pending, will terminate 

12/31/15 

Water District seeking board approval for new agreement 

Mesquite 

Agreement with 

city. However, 

site is located on 

an easement on 

private land. 

City of 

Mesquite 4/30/06 

Complete with City (Private land 

owner has failed to respond and 

provide authorization) 

NLV Airport Agreement 

Clark County 

Department of 

Aviation 

10/19/10 Complete 

Orr MOU Clark County 

School District 5/10/10 Currently in renewal process 
77 

Site Documentation Owner Terms Status of Negotiations

Palo Verde MOU Clark County 

School District 5/10/10 Currently in renewal process 

Paul Meyer Agreement Clark County 4/14/14 Complete 

Sunrise Acres MOU Clark County 

School District 5/10/10 Currently in renewal process 

Walter Johnson MOU Clark County 

School District 5/10/10 Currently in renewal process 

Winterwood MOU Clark County 6/30/25 Complete 

NOTE: BLM = U.S. Bureau of Land Management; MOU = Memorandum of Understanding; NDOT = Nevada Department of Transportation; ROW = 

right-of-way. 
78 

Air Quality System Database Information 

The following table is a compilation of scale and objective information in the AQS database. 

Site Monitor Measurement Scale Monitor Objective Type 

Apex O3 Regional scale Regional transport 

Apex PM10 C-14 Regional scale Source oriented 

Apex PM2.5 C-14 Regional scale Source oriented 

Boulder City O3 Neighborhood Population exposure 

Boulder City PM10 C-14 Neighborhood Population exposure 

E. Craig Road O3 Neighborhood Population exposure 

E. Craig Road PM10 C-14 Neighborhood Highest concentration 

E. Craig Road PM2.5 C-14 Neighborhood Population exposure 

E. Sahara CO Neighborhood Population exposure 

Green Valley PM10 C-14 Middle scale Population exposure 

Green Valley PM2.5 C-14 Middle scale Population exposure 

J.D. Smith CO Neighborhood Population exposure 

J.D. Smith NOx Neighborhood Highest concentration 

J.D. Smith NO2 Neighborhood Highest concentration 

J.D. Smith O3 Neighborhood Population exposure 

J.D. Smith PM10 C-14 Neighborhood Population exposure 

J.D. Smith PM2.5 FRM Neighborhood Population exposure 

J.D. Smith PM2.5 C-14 Neighborhood Population exposure 

Jean O3 Regional scale Regional transport 

Jean PM10 C-14 Regional scale General/background 

Jean PM2.5 FRM Regional scale General/background 

Jean PM2.5 C-14 Regional scale General/background 

Joe Neal NOx Neighborhood Population exposure 

Joe Neal NO2 Neighborhood Population exposure 

Joe Neal O3 Neighborhood Highest concentration 

Joe Neal PM10 C-14 Neighborhood Population exposure 

Lone Mountain O3 Neighborhood Population exposure 

Lone Mountain PM10 C-14 Neighborhood Population exposure 

Mesquite O3 Neighborhood Population exposure 

Mesquite PM10 C-14 Middle scale Population exposure 

Orr CO Neighborhood Population exposure 

Orr O3 Neighborhood Population exposure 

Orr PM10 C-14 Neighborhood Population exposure 

Palo Verde O3 Neighborhood Population exposure 

Palo Verde PM10 C-14 Neighborhood Population exposure 

Paul Meyer O3 Neighborhood Population exposure 
79 

Site Monitor Measurement Scale Monitor Objective Type 

Paul Meyer PM10 C-14 Neighborhood Population exposure 

Sunrise Acres CO Neighborhood Highest concentration 

Sunrise Acres PM10 C-14 Neighborhood Population exposure 

Sunrise Acres PM2.5 FRM Neighborhood Highest concentration 

Sunrise Acres PM2.5 FRM Neighborhood Highest concentration 

Sunrise Acres PM2.5 C-14 Neighborhood Highest concentration 

Walter Johnson O3 Neighborhood Population exposure 

Winterwood CO Neighborhood Population exposure 

Winterwood O3 Neighborhood Population exposure 
80 

Receptor-Measured Criteria Pollutant Trends 

The following pages contain plots of criteria pollutant measurements. In general, NO2 has remained steady over the past few years; CO, O3, and PM have declined; and SO2 has remained insignificant. 

Figure 32 – Carbon Monoxide Trends 

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Year

High 8-Hour Average 

Concentration (ppm) 

E. Flamingo / Orr E. Sahara J.D. Smith Sunrise Acres Winterwood

EPA 8-Hour Standard
81 

Figure 33 – Ozone Trends 

45

50

55

60

65

70

75

80

85

90

95

100

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Year

4th Highest 8-Hour Average

Concentration (ppb)

Palo Verde Joe Neal Lone Mountain

Walter Johnson Paul Meyer Park Apex

Jean Winterwood Craig Road

J.D. Smith Boulder City

Current EPA 8-Hour Standard

1997 EPA 8-Hour Standard
82 

Figure 34 – SO2 Trends 

0

20

40

60

80

100

120

140

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Year

High 24 Hour Average

Concentration (ppb)

E. Sahara Apex*

Boulder City* Searchlight*

EPA 24 Hour Standard

* - Site Discontinued June 30, 2003
83 

Figure 35 – NO2 Trends 

0

5

10

15

20

25

30

35

40

45

50

55

60

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Year

Annual Mean (ppb)

Apex

J.D. Smith

Jean

E. Sahara

Palo Verde

Joe Neal

EPA Annual Standard 
84 

Figure 36 – Continuous PM10 Trends 

0

10

20

30

40

50

60

70

80

90

100

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Year

Annual Mean (μg/M3

)

Apex Boulder City Craig Road E. Flamingo / Orr

Green Valley J.D. Smith Sunrise Acres Paul Meyer Park

Jean Lone Mountain Palo Verde Joe Neal

Mesquite
85 

Figure 37 – Filter-Based PM2.5 FRM Trends 

0

5

10

15

20

25

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Year

Annual Mean (μg/M3

)

J. D. Smith E. Charleston/ Sunrise Acres Jean

EPA Annual Standard
86 

Figure 38 – Continuous PM2.5 Annual Mean Trends 

0

5

10

15

20

25

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Year

Annual Mean (μg/M3

)

Craig Road Green Valley J. D. Smith

 Sunrise Acres Apex Jean
87 

Figure 39 – Continuous vs. Filter-Based PM2.5 Trends 

0

2

4

6

8

10

12

14

16

18

20

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Year

Annual Mean (μg/M3

)

J.D. Smith FRM J.D. Smith BAM

Sunrise Acres FRM Sunrise Acres BAM
88 

Pollen Network 

The pollen network, which is separate from the NAAQS network, is a unique local service DAQEM provides to Clark County residents. It is included in this report for DAQEM use and future 

reference. 

DAQEM operated nine pollen monitoring stations in Clark County during 2009, using the Multidata Model 40 rotorod sampler at each site. The pollen network is located primarily in residential 

areas, and is intended to assess the general population’s pollen exposure levels. Data are reported 

to the public through the DAQEM Web site, the media, and faxed reports; one monitoring station 

also reports pollen levels to the American Academy of Asthma, Allergy, & Immunology three 

days a week. This same station reports pollen levels to the public from July through January. The 

remaining ten stations report data to the public once a week from February through June. 

The two primary producers of allergens in Clark County are the fruitless mulberry and the European olive. The fruitless mulberry pollinates in March, the European olive in April; during these 

months, eight stations operate twice a week. Clark County banned further planting of these trees, 

with the exception of low-pollinating varieties, because of their high levels of pollen (see Section 

44 of the Clark County Air Quality Regulations). 

The pollen monitoring network is dynamic, and monitoring locations change depending on valley growth, pollen levels, and public requests. The following map depicts the current pollen network. 
89 

Figure 40 – Pollen Sampling Locations in Las Vegas, Boulder City, and Apex