Clark County

Department of Air Quality

& Environmental Management

Annual Network Plan Report

June 2011
ii 

Executive Summary 

This annual plan reports the status of the Clark County air monitoring network operated by its 

Department of Air Quality and Environmental Management (DAQEM). 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 2010, planned changes and 

improvements in 2011, efforts to improve data quality, and ways in which the information recorded by the network is disseminated. 

The 2010 network review identified potential deficiencies at three 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 (EPA) finalized revisions to the Lead (Pb) ambient air monitoring requirements on January 26, 2011; revised the National Ambient Air Quality Standard (NAAQS) for sulfur dioxide (SO2) on June 2, 

2010; and revised the NAAQS for nitrogen dioxide (NO2) on January 22, 2010. The EPA requirement to operate a National Core Monitoring Network (NCore) station is discussed in this 

report. In addition, this plan includes a discussion of the regulation changes that affect Clark 

County and its compliance status. 
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Table of Contents 

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

2. Network Review Methodology ............................................................................................... 4

3. Metropolitan Statistical Area .................................................................................................. 5

4. Climatological Information ..................................................................................................... 6

5. Ambient Air Quality Monitoring Methodology ..................................................................... 9

6. Siting Criteria Deficiencies ................................................................................................... 14

7. Design Values for 2010 ........................................................................................................ 15

8. 2010 Site and Instrument Information .................................................................................. 16

9. Monitoring Start Dates in Air Quality System Database ...................................................... 19

10. Monitoring Site Traffic Count Summary .......................................................................... 21

11. Probe and Path Siting for 2010 ......................................................................................... 22

12. Clark County Monitoring Network Sites in 2010 ............................................................. 55

13. Effect of New Regulations on Air Quality Monitoring .................................................... 61

14. Summary of Monitoring Requirements ............................................................................ 63

15. Quality Assurance Program .............................................................................................. 65

16. National Performance Audits ............................................................................................ 68

17. Network Modifications Completed in 2010 ..................................................................... 69

18. Network Modifications Proposed ..................................................................................... 70

19. Status of Monitoring Site Leases ...................................................................................... 73

20. Air Quality System Database Information ........................................................................ 74

21. Receptor-Measured Criteria Pollutant Trends .................................................................. 76

22. Pollen Network ................................................................................................................. 84
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List of Figures 

Figure 1 – Topographic Map ...........................................................................................................8

Figure 2 – Apex .............................................................................................................................23

Figure 3 – Boulder City .................................................................................................................25

Figure 4 – East Craig Road ............................................................................................................26

Figure 5 – East Sahara ...................................................................................................................28

Figure 6 – Green Valley .................................................................................................................30

Figure 7 – J.D. Smith .....................................................................................................................32

Figure 8 – Jean ...............................................................................................................................34

Figure 9 – Jerome Mack ................................................................................................................36

Figure 10 – Joe Neal ......................................................................................................................38

Figure 11 – Lone Mountain ...........................................................................................................40

Figure 12 – Mesquite .....................................................................................................................42

Figure 13 – Orr...............................................................................................................................44

Figure 14 – Palo Verde ..................................................................................................................46

Figure 15 – Paul Meyer..................................................................................................................48

Figure 16 – Sunrise Acres ..............................................................................................................49

Figure 17 – Walter Johnson ...........................................................................................................51

Figure 18 – Winterwood ................................................................................................................52

Figure 19 – Sunrise Hospital..........................................................................................................53

Figure 20 – North Las Vegas Airport ............................................................................................54

Figure 21 – CO Monitors ...............................................................................................................55

Figure 22 – O3 Monitors ................................................................................................................56

Figure 23 – NOx Monitors .............................................................................................................57

Figure 24 – Continuous PM10 Monitors.........................................................................................58

Figure 25 – Continuous PM2.5 Monitors ........................................................................................59

Figure 26 – Filter-Based PM2.5 Monitors.......................................................................................60

Figure 27 – Carbon Monoxide Trends ...........................................................................................76

Figure 28 – O3 Trends ....................................................................................................................77

Figure 29 – SO2 Trends..................................................................................................................78

Figure 30 – NO2 Trends .................................................................................................................79

Figure 31 – Continuous PM10 Trends ............................................................................................80

Figure 32 – Filter-Based PM2.5 FRM Trends .................................................................................81

Figure 33 – Continuous PM2.5 Annual Mean Trends.....................................................................82

Figure 34 – Continuous vs. Filter-Based PM2.5 Trends .................................................................83

Figure 35 – Pollen Sampling Locations in Las Vegas and Boulder City ......................................85

 
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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 

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 

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 any ozone (O3) monitoring site that exceeds the 2010 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 2010. 

11. Identification of projected network changes during calendar year 2011 and beyond. 

12. Description of plans to correct guidance conflicts. 

During 2010, the following conditions existed: 

1. DAQEM operated air quality instruments to measure ambient concentrations of the following criteria pollutants: PM2.5, PM10, O3, carbon monoxide (CO), and nitrogen oxides 

(NO, NO2, NOx). 

2. DAQEM operated visibility instrumentation, including long-path transmissometers and 

visibility cameras, as a special project. 

3. DAQEM counted pollen as a special project. 

4. DAQEM operated with the following program objectives: 

a. Ensure that the network is monitoring representative data, and that 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 using long-path visibility technology and visibility cameras. 

d. Review analyzer placement for O3 boundaries, considering formation and transport. 

e. Improve forecasting methods for O3, PM10, and PM2.5. 

f. Make efforts to update and maintain monitoring equipment. 

g. Develop and implement a corrective action plan (CAP) in response to the EPA 2009 

technical system audit (TSA). 

h. Revise standard operating procedures (SOPs). 

i. Deploy National Core Monitoring Network (NCore) site. 
2 

5. Parts of Clark County are designated nonattainment for two criteria pollutants: PM10 in 

Hydrographic Area (HA) 212, and O3 in HAs 164A, 164B, 165, 166, 167, 212, 213, 214, 

216, 217, and 218. 

a. The Las Vegas Valley (HA 212) was designated nonattainment for PM10 in the late 

1980s, and in 1993 it was reclassified as “serious” nonattainment under the 1990 National Ambient Air Quality Standards (NAAQS) for PM10. Since the end of 2006, 

however, Clark County has maintained compliance with the 1990 PM10 NAAQS. 

DAQEM is now developing a PM10 Request for Redesignation and Maintenance Plan

for submittal to EPA in the summer of 2011. In addition, exceptional event demonstration packages have been submitted to EPA for one PM10 exceedance in 2007 (not 

flagged, not deemed questionable data) and two in 2008. 

b. In April 2004, parts of Clark County were designated nonattainment for the 1997 O3

NAAQS. Based on 2008-2010 monitoring data, Clark County has been in compliance 

with the 1997 O3 NAAQS. DAQEM submitted an Ozone Request for Redesignation 

and Maintenance Plan to EPA. 

c. The Las Vegas Valley was designated “moderate” nonattainment for the 1990 CO 

NAAQS in 1997, and in 2000 redesignated “serious” nonattainment. In June 2005, 

EPA determined that the Las Vegas Valley had attained the 1990 CO NAAQS by the 

applicable date of December 31, 2000, making the area eligible to submit a request 

for redesignation to attainment status. In 2008, DAQEM prepared and submitted the 

CO Request for Redesignation and Maintenance Plan, which EPA approved in September 2010. Clark County is thus currently designated a maintenance area for CO. 

d. Clark County is in attainment or unclassifiable for PM2.5, NO2, lead (Pb), and sulfur 

dioxide (SO2). 
3 

Below is a picture of the Engineering Division, which includes the Air Quality Monitoring and 

Quality Assurance Team. From left to right: Christian Francis, Management Analyst II; Mickey 

Palmer, Senior Air Quality Monitoring Technician; Pravin Pema, Air Quality Monitoring Technician II; Matt Nelson, Air Quality Monitoring Technician II; Mike Sword, Air Quality Engineering Manager; Mickey Turner, Senior Air Quality Monitoring Technician; Yousaf Hameed, 

Air Quality Monitoring Supervisor; David Dickens, Air Quality Monitoring Technician II; Brandon Cunningham, Senior Management Analyst; Phil Wiker, Senior Air Quality Monitoring 

Technician; Kris Simonian, Air Quality Monitoring Technician II; Joe Biebrich, Air Quality 

Monitoring Technician II; and Gregory Weber, Senior Office Specialist (not pictured). 

 
4 

2. 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 the supervisor, field technicians, data management specialist, planning staff, quality assurance technician, 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 O3 and PM2.5. 
5 

3. 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 the 

Cities of Mesquite and Boulder City, do not qualify as Metropolitan Statistical Areas. 
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4. Climatological Information 

Information within this section was taken from the National Weather Service’s Las Vegas climate book (Climate of Las Vegas, Nevada, 2005). 

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 the Eldorado Valley and Lake Mead 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. 

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 
7 

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 O3 concentrations on the west and northwest sides of the valley. O3 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 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. 

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 meter/second [m/s]) wind speeds. 

The center’s surface analyses indicate that southern Nevada is enveloped by a thermal lowpressure system. 
8 

Figure 1 – Topographic Map 
9 

5. Ambient Air Quality Monitoring Methodology 

DAQEM operated 16 monitoring stations in Clark County during 2010. Monitor types vary from 

station to station. The network consists primarily of State and Local Air Monitoring Stations 

(SLAMS) with a neighborhood-scale focus intended to assess the exposure levels of the general 

population. The network, which also characterizes pollution transport and background levels, 

contains subnetworks for the EPA criteria pollutants PM10, PM2.5,CO, O3, and NO2. 

Continuous Particulate Matter Monitors 

The sampling method employs the continuous Thermo Electron FH62C14 series monitor, which 

uses carbon-14 as the beta source. All continuous PM2.5 monitors have a Very Sharp Cut Cyclone (VSCC) as their second stage separator. 

Particulate Matter of 10 Microns or Less

DAQEM operated 13 continuous PM10 monitors in Clark County in 2010, nine inside the Las 

Vegas Valley and four outside it. The map in the section “Continuous PM10 Monitoring Locations in 2010” shows the locations of the monitors in the PM10 monitoring network (Figure 23). 

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 oriented 

Craig Road Neighborhood Highest concentration 

All others Neighborhood Population exposure 

Particulate Matter of 2.5 Microns or Less

In 2010, DAQEM operated six continuous PM2.5 monitors in Clark County. The map in the section titled “Continuous PM2.5 Monitoring Locations in 2010” shows the locations of the monitors 

in the continuous PM2.5 monitoring network (Figure 24). 

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. 
10 

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 General/background 

Filter-Based Particulate Matter Samplers 

The PM2.5 federal reference method (FRM) and PM2.5 speciation samplers, the latter of which includes a University Research Glassware (URG) carbon channel sampler, are the only filter-based 

monitoring instruments DAQEM employs. The map in the section “Filter-Based PM2.5 Monitoring Locations in 2010” shows the locations of the samplers in the PM2.5 FRM monitoring network (Figure 25). 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

The following table lists the four filter-based PM2.5 FRM samplers (plus collocated) that 

DAQEM operated in 2010. 

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 

Jerome Mack One in three days 

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

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

 
11 

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

PM2.5 FRM sampler. 

Site Spatial Scale Objective

Jean Regional Background 

Sunrise Acres Neighborhood Highest concentration 

J.D. Smith Neighborhood Population exposure 

Jerome Mack Neighborhood Population exposure 

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

the NAAQS or if a community monitoring zone (as defined in 40 CFR § 58.10 (8)(c)) is created 

or changed. DAQEM will notify the community of a proposed zone change by (1) posting a review of the PM2.5 monitoring network to its Web site with the changes being considered, and (2) 

soliciting feedback from the community. DAQEM will consider and respond to all public comments before making changes to the PM2.5 network. Exceptions to the review process will be 

made only for a lost lease or a notice from the property owner to vacate a site. 

40 CFR § 58.30(a)(1) states that samples from certain types of microscale sites are unsuitable for 

comparison to the annual PM2.5 NAAQS. DAQEM does not operate a microscale PM2.5 site, so 

all its PM2.5 samples are suitable for NAAQS comparisons. 

Speciation 

DAQEM operated a SASS speciation sampler in conjunction with a carbon channel URG sampler at the East Craig Road site (32-003-0022) until April 30, 2010, when the unit was moved to 

the Jerome Mack NCore site (32-003-0540). Speciation sampling occurs on a one-in-three day 

schedule, which is the same schedule as the PM2.5 FRM network. DAQEM provides speciation 

samples to Research Triangle Institute who analyzes the speciation samples and reports the results to the AQS. 

Carbon Monoxide 

DAQEM uses API 300 Series CO monitors with gas filter correlation. The map in the section 

“Carbon Monoxide Monitoring Locations in 2010” shows the locations of the monitors in the 

CO monitoring network (Figure 20). 

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

quarterly. Twenty-five percent of the monitors undergo a QA audit every quarter, and all are audited at least once a 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 
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Ozone 

In 2010, DAQEM operated 17 API 400 Series ultraviolet absorption O3 monitors in Clark County. Nine operated inside the Las Vegas Valley; four operated outside it; and four operated as part 

of a summer study. The map in the section “O3 Monitoring Locations in 2010” shows the locations of the monitors in the O3 monitoring network (Figure 21). The network was originally designed for comparison to the one-hour O3 NAAQS, but was modified to calculate eight-hour 

(rolling average) values when EPA changed the standard in 1997. 

DAQEM’s O3 projects include: 

• Ozone Characterization Study. 

• Clark County Regional Ozone and 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. 

• Characterization of 2010 wildfire impacts on air quality in Clark County. 

DAQEM is planning another wildfire study in the summer of 2011 to evaluate how transport and 

ozone at upper altitudes affects O3 levels, and O3 formation in Clark County. These studies 

should contribute to a better understanding of O3 transport impacts and more thorough exceptional event demonstrations. 

DAQEM conducts a three-point QC check on O3 monitors every week and calibrates them quarterly. Twenty-five percent of the monitors undergo a QA audit every quarter, and all are audited 

at least once a year. 

The following table shows the spatial scale and monitoring objective for each O3 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 2010, DAQEM operated two API 200 Series NOx monitors with gas phase chemiluminescence inside the Las Vegas Valley. The map in the section “Nitrogen Oxides Monitoring Locations in 2010” shows the locations of monitors in the NOx monitoring network (Figure 22). 

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

quarterly. Twenty-five percent of the monitors undergo a QA audit every quarter, and all are audited at least once a year. 
13 

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

Site Spatial Scale Objective

J.D. Smith Neighborhood Highest concentration 

Joe Neal Neighborhood Population exposure 
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6. Siting Criteria Deficiencies 

DAQEM identified the following deficiencies in its 2010 review of the monitoring network. 

Site Roadway Obstacle Distance

E. Sahara CO - 

Walter Johnson - Water cooling tower 15’ from inlet 

Green Valley - 

Tree drip line 2 m from inlet; tree base 

4 m from inlet 

The following table shows the schedule for correcting these deficiencies. 

Deficiency Site/Monitor Corrective Action Schedule

Spacing from roads E. Sahara/CO Resolved: moved to Jerome Mack Middle School. 2010

Obstacle distance Walter Johnson/O3 Monitor data for impacts from cooling tower. 2011

Obstacle distance Green Valley/PM2.5 Coordinate with city to have tree trimmed. 2011 

Spacing from Roads 

DAQEM evaluated the spacing from roads issue at the East Sahara site and made needed corrections to comply with 40 CFR § 58, Appendix E. Both of the following options were employed: 

1. Relocate the site. 

2. Shut down the site. 

Obstacle Distance 

DAQEM will evaluate the obstacle distance issue at the Walter Johnson and Green Valley sites 

and attempt to bring both into compliance with 40 CFR § 58, Appendix E. One or more of the 

following options will be employed: 

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

2. Trim or remove the tree. 

3. Relocate the site. 

4. Shut down the site. 
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7. Design Values for 2010 

The following table compares O3 design values with the NAAQS standard. 

Station O3 Design Value (ppm) NAAQS Standard (ppm)

E. Craig Road 0.070 0.075 

Winterwood 0.069 0.075 

Apex 0.069 0.075 

Lone Mountain 0.070 0.075 

Palo Verde 0.072 0.075 

Jean 0.073 0.075 

Paul Meyer 0.072 0.075 

Boulder City 0.070 0.075 

J.D. Smith 0.069 0.075 

Walter Johnson 0.074 0.075 

Joe Neal 0.076 0.075 

Mesquite .0.064 0.075 

Orr 0.068 0.075 

Note: ppm = parts per million. 

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

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

Sunrise Acres 8.5 15 

Jean 3.9 15 

J.D. Smith 7.8 15 

Note: μg/m3 = micrograms per meter cubed.

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

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

Sunrise Acres 21 35 

Jean 11 35 

J.D. Smith 17 35 

40 CFR § 58.30(a)(1) states that samples from certain types of microscale sites are unsuitable 

for comparison to the annual PM2.5 NAAQS. DAQEM does not operate a microscale PM2.5 site, 

so all its FRM PM2.5 samples are suitable for NAAQS comparisons. 
16 

8. 2010 Site and Instrument Information 

Site Information 

Apex (32-003-0022). The primary objective of this site approximately 25 miles northeast of Las 

Vegas is to monitor the ambient impacts of emissions from nearby gravel processing and power 

plants. Since the site is generally downwind from Las Vegas, it also serves as an indicator of pollutant transport flow out of the Las Vegas Valley. It is the only DAQEM monitoring station in 

the Apex Valley. 

Boulder City (32-003-0601). This site approximately 25 miles southeast of Las Vegas was established at the request of Boulder City government officials and residents to serve as an indicator 

of population exposure to pollutants, particularly O3 and PM10. This monitoring site is in operation to serve as an indicator of population exposure for pollutants. 

Craig Road (32-003-0020). This site in the City of North Las Vegas was established to comply 

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

in the past it has periodically exceeded the PM10 24-hour standard, this site has not experienced a 

PM10 exceedance since May 2008. 

 

Green Valley (32-003-0298). This site in Henderson was established in response to citizen complaints about dust emissions from a gravel processing plant, and continues to monitor PM10 and 

PM2.5. 

J.D. Smith (32-003-2000). This site in North Las Vegas replaced the old McDaniel and Post Office PM sites. It monitors gaseous (NOx, CO, and O3) and particulate (PM10 and PM2.5) pollutants 

using both filter-based and continuous methods. It also serves as an indicator of population exposure to pollutants. 

Jean (32-003-1019). The primary objective of this site approximately 30 miles south of Las Vegas is to monitor transport pollutants from southern California; O3, PM10, and continuous and filter-based PM2.5 are monitored at this site. 

Jerome Mack (32-003-0540). This site on the east side of Las Vegas contains the EPA NCore 

monitor. Its primary objective is to monitor trace level gaseous pollutants, PM parameters (including PM2.5, PM coarse, and speciated PM parameters), and meteorological parameters as part 

of the nationwide network. Because of NCore requirements, speciation sampling was moved 

here from the East Craig Road site in May 2010. 

Joe Neal (32-003-0075). The primary objectives of this site in northwest Las Vegas are to monitor O3 and its precursors in an area of high concentrations and to support DAQEM modeling efforts. 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 
17 

valley; this site continues to serve as a high O3 indicator for the Las Vegas Valley. A NOx monitor was added in January 2008. 

Lone Mountain (32-003-0072). The primary objective of this site in northwest Las Vegas 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 Monitoring was initiated in 

1998 because of gravel processing to the west/northwest of the site. 

East Sahara (32-003-0539). Centrally located in the Las Vegas Valley, this is one of DAQEM’s 

oldest monitoring sites. Its primary objective is to monitor CO, but it also serves as an indicator 

of population exposure to pollutants. Historically, this site demonstrated the ability to monitor 

for the regional effects of SO2, CO, & O3. 

Mesquite (32-003-0023). This site approximately 70 miles north of Las Vegas monitors O3 and 

PM10. It sits along a transport and exit corridor for jurisdictional boundaries, and serves as an indicator of population exposure to pollutants. 

 

Orr (32-003-1021). This replaced the East Flamingo site, which was terminated because the 

lease was lost and it was too close to the road to meet its O3 monitoring objective. DAQEM began monitoring O3 at Orr in April 2006, and continues monitoring CO and PM10 here. The site 

also serves as an indicator of population exposure to pollutants. 

Paul Meyer (32-003-0043). The primary objective of this site in southwest Las Vegas is to monitor O3, although PM10 is also monitored here. 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. 

Palo Verde (32-003-0073). The primary objective of this site in west Las Vegas is to monitor O3, 

although PM10 is also monitored here. 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. 

Sunrise Acres (32-003-0561). Monitoring at this site near the center of the Las Vegas Valley began as part of a CO study in the 1990s, and its primary objective is still to monitor CO. All monitoring activities at the East Charleston site were transferred here when that lease was lost. The 

site monitors PM10 and PM2.5 using both filter-based and continuous methodologies, and serves 

as the primary and collocated sampling site for PM2.5 FRM samplers. 

Walter Johnson (32-003-0071). The primary objective of this site on the west side of Las Vegas 

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). This site on the east side of Las Vegas is one of DAQEM’s oldest 

sites. Its primary objective is to monitor CO and O3, but it also serves as an indicator of population exposure to pollutants. 

No DAQEM monitoring site is located near furnaces or incinerators. 
18 

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 and cameras. 

The following table demonstrates 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 

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 house a meteorological tower equipped with an ultrasonic 

wind speed/wind direction sensor and an ambient temperature sensor at a height of 10 m. Some 

of the meteorological monitoring stations also have relative humidity (at a height of 10 m), precipitation, and solar radiation sensors. 
19 

9. Monitoring Start Dates in Air Quality System Database 

The following table shows monitoring start dates in AQS. 

Site Name Site ID Parameter Description AQS Parameter

Code POC Date Sampling Began 

Apex 0022 NO2 42602 1 01-Jan-1998 

Apex 0022 O3 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 O3 44201 1 01-Jul-1998 

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

E. Craig Road 0020 O3 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 01-Jan-2007 

E. Sahara 0539 CO 42101 1 01-Jan-1998 

E. Sahara 0539 SO2 42401 1 01-Jan-1998 

E. Sahara 0539 NO2 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 NO2 42602 1 01-Oct-1998 

J.D. Smith 2002 CO 42101 1 01-Oct-1998 

J.D. Smith 2002 O3 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 O3 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 

Jerome Mack 0540 PM2.5 - speciation 88101 5 01-May-2010 

Jerome Mack 0540 PM2.5 - local conditions 88101 1 01-Oct-2010 

Joe Neal 0075 O3 44201 1 01-Jul-2000 

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

Joe Neal 0075 NO2 42602 1 01-Jan-2008 

Lone Mountain 0072 O3 44201 1 01-Jan-1998 

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

Mesquite 0023 NO2 42602 1 01-Nov-2001 

Mesquite 0023 O3 44201 1 01-Oct-2001 

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

Orr 1021 CO 42101 1 01-Oct-2002 
20 

Site Name Site ID Parameter Description AQS Parameter

Code POC Date Sampling Began 

Orr 1021 O3 44201 1 01-Apr-2006 

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

Palo Verde 0073 NO2 42602 1 01-Aug-1998 

Palo Verde 0073 O3 44201 1 01-Jul-1998 

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

Paul Meyer Park 0043 O3 44201 1 01-Jul-1998 

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

Sunrise Acres 0561 CO 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 O3 44201 1 01-Aug-1998 

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

Winterwood 0538 CO 42101 1 01-Jan-1998 

Winterwood 0538 O3 44201 2 01-Jul-1979 

Note: POC = parameter occurrence code; STP = standard temperature and pressure. 
21 

10. Monitoring Site Traffic Count Summary 

The following table 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 m to U.S. Hwy. 93 2,300 70,000/30,000 

Boulder City 57 m to Industrial 19,000 40,000/20,000 

E. Craig Road 34 m to Mitchell 4,300 20,000/15,000 

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

Green Valley 12.2 m to Santiago 3,900 10,000/10,000 

J.D. Smith 180 m to Bruce 8,500 70,000/60,000 

Jean 1287 m to State Hwy. 161 1,700 110,000/60,000 

Jerome Mack 484 m to Lamb 30,000 70,000/60,000 

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

Lone Mountain 50 m to Valadez 5,300 40,000/20,000

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

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

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

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

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

Walter Johnson 13 m to Villa Monterrey 12,000 10,000/≤10,000 

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

1Distance 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 = O3 and NO2 for urban and neighborhood scale; Table E-2 = CO for neighborhood scale. 
22 

11. Probe and Path Siting for 2010 

Monitoring stations: 

• Apex 

• Boulder City 

• East Craig Road 

• East Sahara 

• Green Valley 

• J.D. Smith 

• Jean 

• Jerome Mack 

• Joe Neal 

• Lone Mountain 

• Mesquite 

• Orr 

• Palo Verde 

• Paul Meyer 

• Sunrise Acres 

• Walter Johnson 

• Winterwood 

Visibility sites: 

• Bank of America 

• Sunrise Hospital 

• North Las Vegas Airport 
23 

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 

Universal Transverse Mercator (UTM) X-Coordinate: 667652.800; 

UTM Y-Coordinate: 4004823.000 

Operative Schedule: 24 hours 

Sampling Methods: O3: Ultraviolet Absorption, API 400 

PM10: Beta Attenuation, Thermo Electron FH62C14 

PM2.5: Beta Attenuation, Thermo Electron FH62C14 

Predominant Wind Direction: South 

Photograph Direction: South 

PM10 PM2.5 Continuous O3

Spatial scale Regional Regional Regional 

Monitoring objective Source-oriented General/Background 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 
24 

PM10 PM2.5 Continuous O3

Obstructions on roof None None — 

Obstacle distance None None None 

Probe material — — Teflon 

Residence time — — 1.9 s 
25 

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 Methods: O3: Ultraviolet Absorption, API 400E 

 PM10: Beta Attenuation, Thermo Electron FH62C14 

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 
26 

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 Methods: O3: Ultraviolet Absorption, API 400A 

PM2.5: Beta Attenuation, Thermo Electron FH62C14 

PM10: Beta Attenuation, Thermo Electron FH62C14 

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 
27 

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 — — 
28 

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: CO: Gas Filter Correlation API 300E 

Predominant Wind Direction: Southwest 

Photograph Direction: East 

Changes: Moved to Jerome Mack Middle School; new shelter; operating at NCore 

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 — 

Obstacle distance — 
29 

CO

Probe material — 

Residence time 2.7 s 
30 

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 Methods: PM2.5: Beta Attenuation, Thermo Electron FH62C14 

PM10: Beta Attenuation, Thermo Electron FH62C14 

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 4.6 m 2.0 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 — — 
31 

PM10 PM2.5 Continuous 

Obstructions on roof — — 

Obstacle distance 6.9 m 6.3 m 

PM Probe material Stainless steel Stainless steel 

Residence time — — 
32 

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 Methods: O3: Ultraviolet Absorption, API 400A 

CO: Gas Filter Correlation Analyzer, API 300E 

PM10: Beta Attenuation, Thermo Electron FH62C14 

PM2.5: Beta Attenuation, Thermo Electron FH62C14 

PM2.5: Andersen RAAS2.5-300 FRM 

NO2: 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 

Highest 

concentration

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° 
33 

 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 — 
34 

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 Methods: O3: Ultraviolet Absorption, API 400E 

PM10: Beta Attenuation, Thermo Electron FH62C14 

PM2.5: Beta Attenuation, Thermo Electron FH62C14 

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 General/Background Regional 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 
35 

 PM10

PM2.5

Continuous O3 PM2.5 (FRM) 

Distance between 

collocated monitors 2.7 m 2.7 m — 10 m 

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

Spacing from supporting structure — — 1.4 m — 

Obstructions on roof — — — — 

Obstacle distance — — — — 

Probe material — — Teflon — 

Residence time — — 1.6 s — 

 
36 

Figure 9 – Jerome Mack 

Type: NCore 

Jerome Mack (JM) (32-003-0540) 

Location: 4250 Karen Avenue, 89121-1832: 1758’ elevation 

Three Closest Roads: Lamb, Nellis, and East Sahara 

UTM X-Coordinate:36.138467; UTM Y-Coordinate: 115.073854 

Operative Schedule: 24 hours 

Sampling Methods: SO2: TAPI 100E 

NOx: TAPI 200EU 

Nitrogen compounds: TAPI 501Y 

CO: TAPI 300EU 

O3: Ultraviolet Absorption, API 400E 

Chemical speciation: Met One Instruments SASS 

Reference Ambient Air Sampler: Andersen Instruments PM2.5-300 

PM10, PM2.5, and PM10-2.5: MetOne BAM 1020 Pair 

Chemical Carbon: Sequential Particulate Speciation System: URG-3000N 

Predominant Wind Direction: South (light and variable) 

Photograph Direction: Southwest 
37 

PM10

Continuous 

PM2.5

Continuous 

PM10-2.5

Continuous PM2.5 (FRM) Speciation SASS Speciation URG O3 NOY 

Spatial scale — — — Neighborhood Neighborhood Neighborhood Neighborhood Urban NMonitoring objective — — — 

Population 

exposure 

Population 

exposure 

Population 

exposure 

Population 

exposure 

Population 

exposure 

Vertical probe placement — — — 2.1 m 1.6 m 1.8 m 12.8 m 13.6 m Unrestricted airflow — — — 360° 360° 360° 360° 360° Spacing from trees — — — 25 m 25 m 25 m 18 m 19 m Spacing from station to road — — — 482 m 482 m 482 m 482 m 482 m Distance between collocated monitors — — — — 2.3 m 2.3 m — — Ground cover — — — Concrete/ 

grass 

Concrete/ 

grass 

Concrete/ 

grass 

Grass Grass 

Spacing from supporting structure — — — Free- standing Free- standing Free- standing 1.3 m 0.4 m Obstructions on roof — — — — — — None None Obstacle distance — — — 25 m 25 m 25 m 19 m 19 m Probe material — — — — — — Teflon Teflon Residence time — — — — — — 3.8 s 10.1 s 
38 

Figure 10 – 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 Methods: O3: Ultraviolet Absorption, API 400A 

PM10: Beta Attenuation, Thermo Electron FH62C14 

NO2: 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 
39 

PM10 O3 NO2

Probe material — Teflon Teflon 

Residence time — 2.1 s 2.1 s 

 
40 

Figure 11 – 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 Methods: O3: Ultraviolet Absorption, API 400 

PM10: Beta Attenuation, Thermo Electron FH62C14 

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 
41 

PM10 O3

Probe material — Teflon 

Residence time — 10.7 s 

 
42 

Figure 12 – 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 Methods: O3: Ultraviolet Absorption, API 400A 

PM10: Beta Attenuation, Thermo Electron FH62C14 

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 
43 

PM10 O3

Probe material — Teflon 

Residence time — 10.3 s 
44 

Figure 13 – 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 Methods: CO: Gas Filter Correlation CO Analyzer, API 300E 

O3: Ultraviolet Absorption, API 400E 

PM10: Beta Attenuation, Thermo Electron FH62C14 

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 — — 
45 

PM10 CO O3

Obstacle distance No obstacles — — 

Probe material — — Teflon 

Residence time — — 3.5 s 
46 

Figure 14 – 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 Methods: O3: Ultraviolet Absorption, API 400E 

PM10: Beta Attenuation, Thermo Electron FH62C14 

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 — — 
47 

PM10 O3

Probe material — Teflon 

Residence time — 2.1 s 
48 

Figure 15 – 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 Methods: O3: Ultraviolet Absorption, API 400A 

PM10: Beta Attenuation, Thermo Electron FH62C14 

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 
49 

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 Methods: CO: Gas Filter Correlation, API 300E 

PM10: Beta Attenuation, Thermo Andersen FH62C14 

PM2.5: Beta Attenuation, Thermo Electron FH62C14 

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 — — — — — 
50 

 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 — — — 
51 

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: O3: 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 
52 

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 Methods: O3: Ultraviolet Absorption, API 400A 

CO: 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 
53 

Figure 19 – Sunrise Hospital 

Type: Transmissometer (Visibility Monitoring Network) 

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 

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 

 
54 

Figure 20 – North Las Vegas Airport 

Type: Visibility Camera (Visibility Monitoring Network) 

North Las Vegas Airport 

Location: 2730 Airport Drive, North Las Vegas, NV 89032 

Three closest roads: Cheyenne Ave., North Decatur Blvd., North Rancho Drive 

Equipment: High-Resolution Digital Camera System, Olympus E-420 Series 
55 

12. Clark County Monitoring Network Sites in 2010 

Figure 21 – CO Monitors 
56 

Figure 22 – O3 Monitors 

Note: Red dots indicate 2010 summer O3 study sites. 
57 

Figure 23 – NOx Monitors 

 
58 

Figure 24 – Continuous PM10 Monitors 
59 

Figure 25 – Continuous PM2.5 Monitors 
60 

Figure 26 – Filter-Based PM2.5 Monitors 
61 

13. Effect of New Regulations on Air Quality Monitoring

On November 12, 2008, EPA released the revised NAAQS for Pb. Revisions to the Pb ambient 

air monitoring rule was finalized on January 26, 2011 [75 FR 81126 (December 27, 2010)]. As a 

result of these changes, Clark County must now address two Pb monitoring requirements: ambient nonsource-oriented monitoring and ambient source-oriented monitoring. DAQEM plans to 

initiate ambient nonsource-oriented Pb monitoring at the NCore site by January 2012 and has 

asked Region 9 for authorization to use the nationally contracted Research Triangle Institute laboratory for sample analysis. The source emission threshold for the ambient source-oriented 

monitoring requirement is 0.50 tons per year, and DAQEM is identifying potential sources that 

may trigger that requirement. A preliminary assessment shows no such sources within Clark 

County, but an official emissions inventory is being conducted and will be provided at a later 

date. The DAQEM Quality Assurance Project Plan for Pb was submitted to EPA June 30, 2010. 

On June 2, 2010, EPA strengthened the primary NAAQS for SO2: it revoked the two existing 

standards, 140 ppb over 24 hours and 30 ppb over a year, and established a new 1-hour standard 

of 75 ppb. Newly sited SO2 monitors must be operational by January 1, 2013. In addition to 1-

hour averages, DAQEM will also report maximum 5-minute block averages in accordance with 

the revised SO2 rule. Historically, SO2 data in Clark County is well below the NAAQS; therefore, DAQEM will operate one SO2 monitor at the NCore site. 

On January 22, 2010 [75 FR 6474 (February 9, 2010)] EPA revised the primary NAAQS for 

NO2. EPA established requirements for an NO2 monitoring network with monitors sited at locations where maximum NO2 concentrations are expected to occur, including within 50 m of major 

roadways, and monitors sited to measure the area-wide NO2 concentrations that occur more 

broadly across communities. DAQEM is currently investigating siting locations and believes that 

the City Center site (32-003-0016) will meet this requirement. City Center is one of the valley’s 

ten highest traffic count areas. Its diverse traffic mix includes older vehicles and it experiences 

significant congestion at least twice per day. It 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., the 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; a 

previous study determined that O3 was undergoing titration by NOx from vehicles on U.S. 95. In 

addition, City Center has the flexibility to qualify for neighborhood scale monitoring. New roadside NO2 monitors must begin operating no later than January 1, 2013. 

On January 28, 2011, EPA proposed retaining the existing NAAQS for CO. Although the primary standard will not change, a requirement for near-road monitoring is expected to be established. 

DAQEM anticipates collocating near-road CO monitoring with the near-road NO2 monitor. 

40 CFR § 58.10(3) requires that NCore stations be operational by January 1, 2011, and DAQEM 

is operating a new NCore monitoring station at Jerome Mack Middle School in accordance with 

40 CFR § 58, Appendix D. PM Coarse monitoring will also commence at Jerome Mack in 2011. 
62 

All monitoring instruments are operated continuously year-round except PM2.5 FRM samplers, 

speciation samplers, and monitors for seasonal studies. O3 monitoring at Mesquite and Apex may 

also be conducted in conjunction with summer O3 studies. 
63 

14. Summary of Monitoring Requirements 

40 CFR § 58 dictates the maintenance requirements for ambient air monitoring networks. 

DAQEM continuously considers those requirements in its network design, leading to the results 

listed beneath each requirement below. 

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

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

Ave., Las Vegas, NV. 

• The area of highest O3 concentration is the Joe Neal station at 6651 W. Azure Way, 

Las Vegas, NV. 

• The area of highest PM10 concentration is the Apex station (now closed) at 12101 

U.S. Highway 93, Las Vegas, NV. Second highest is the Joe Neal station at 6651 W. 

Azure Way, Las Vegas, NV. 

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

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

1301b E. Tonopah Dr., Las Vegas, NV. 

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

• City of Las Vegas: 

- Annual average CO concentration is 0.56 ppm. 

- Annual average O3 concentration is 0.053 ppm. 

- Annual average PM10 concentration is 24.93 μg/m3. 

- Average PM2.5 concentration is 7.42 μg/m3

. 

- Annual average NO2 concentration is 0.013 ppm. 

• City of Henderson: 

- Annual average PM10 concentration is 14.8 μg/m3. 

- Average PM2.5 concentration is 5.56 μg/m3. 

• City of Boulder City: 

- Annual average O3 concentration is 0.052 ppm. 

- Annual average PM10 concentration is 12.6 μg/m3

. 

• City of Mesquite: 

- Annual average O3 concentration is 0.049 ppm. 

- Annual average PM10 concentration is 13.3 μg/m3. 

3. Determine the impact significant sources have 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: one exceedance day because of fireworks. 

• PM10 sources: fugitive dust, industrial processes. 

- Impact: zero exceedance days. 

4. Determine general background concentration levels. 
64 

• Jean: 

- PM10: 2010 average = 8.7 μg/m3. 

- PM2.5: 2010 average = 3.45 μg/m3. 

- O3: 2010 average = 0.053 ppm. 

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

• Studies show that O3 transport and regional contributors have an influence on Clark 

County, which may result in O3 exceedances. Smoke from seasonal wildfires may 

contribute significantly to O3 and PM levels in Clark County. 

6. Determine health and 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 rural population and is located at an outflow transport corridor adjacent to a jurisdictional boundary. 

Clark County Air Monitoring Network 

The table below shows the network meets or exceeds the minimum requirements of 40 CFR § 

58. 

Pollutant Monitors Required Monitors in service in 2010

CO 0 5 

O3

2 

13 year around operations 

5 summer study (including 1 chemiluminescent) 

SO2 0 0 

NO2 0 2 

PM10 BAM 4-8 13 

PM2.5 BAM 0 6 

PM2.5 FRM 2 + collocation 4 + collocation 

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

its ability 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. 

9. Departmental resources. 

Applicable state implementation and maintenance plans require no additional instrumentation. 
65 

15. Quality Assurance Program 

DAQEM conducted performance field evaluations throughout 2010. 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, including two NO2 instruments, five CO instruments, and thirteen O3 instruments. The only failure of DAQEM Measurement Quality Objectives took place at the Boulder City site on June 22, 2010, caused by a 

calibrator flaw; the instrument was promptly recalibrated, and a follow-up audit on August 13 

was satisfactory. Five O3 sites, including Apex, Craig Road, Lone Mountain, Mesquite, and Orr 

Middle School, were shut down, but may be used again for special studies. DAQEM has no SO2

instruments to audit. 

Five RAAS300-2.5 samplers at three monitoring sites were evaluated, along with one SASS. The 

SASS was initially sited at East Craig Road, then moved to Jerome Mack Middle School. Thirteen continuous PM10 C-14 BAMs and six continuous PM2.5 C-14 BAMs underwent performance evaluations for flow, temperature, pressure, and time. Five PM10μ monitoring sites—

Apex, East Craig Road, Lone Mountain, Mesquite, and Orr Middle School—had been shut down 

by the end of 2010, as had two PM2.5μ sites—Apex and Craig Road. 

Each continuous PM2.5 BAM is equipped with a VSCC as a second stage separator. PM2.5 FRM 

samplers are equipped with a mix of VSCC separators and Well Impactor Ninety-Six impactors. 

Each operational PM2.5 FRM was audited quarterly in 2010 for a total of fifteen evaluations of 

the three sites (including Sunrise Acres, which hosts the precision pair). In the final quarter of 

2010, the FRM at J.D. Smith was moved to Jerome Mack. All continuous particulate monitors 

were evaluated semiannually. 

Evaluations were balanced throughout the calendar year. Any scheduling adjustments favored 

pollutant seasonality, e.g., more CO instruments were audited during the winter months and 

more O3 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 (LEADS), 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. Precise and accurate 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 2010 schedule for internal QA performance evaluations. 

 

Date Pollutant Monitoring Stations

3/10/2010 PM10 Jean, Green Valley, Paul Meyer 

3/11/2010 PM10 Lone Mountain, Palo Verde 

3/12/2010 PM10 Mesquite 

4/22/2010 PM10 Orr 
66 

Date Pollutant Monitoring Stations

6/8/2010 PM10 Craig Road, J.D. Smith, Joe Neal, Sunrise Acres 

6/22/2010 PM10 Boulder City 

9/1/2010 PM10 Green Valley, Jean 

9/10/2010 PM10 Paul Meyer 

9/29/2010 PM10 Palo Verde 

10/25/2010 PM10 Boulder City 

10/27/2010 PM10 Joe Neal 

11/8/2010 PM10 Sunrise Acres 

11/29/2010 PM10 J.D. Smith 

3/10/2010 PM2.5 continuous Green Valley, Jean 

3/12/2010 PM2.5 continuous Apex 

6/8/2010 PM2.5 continuous Craig Road, J.D. Smith, Jean 

9/1/2010 PM2.5 continuous Green Valley, Jean 

9/10/2010 PM2.5 continuous Apex 

9/16/2010 PM2.5 continuous Craig Road 

11/8/2010 PM2.5 continuous Sunrise Acres 

11/9/2010 PM2.5 continuous J.D. Smith 

3/26/2010 PM2.5 filter-based Jean, Sunrise Acres, J.D. Smith 

5/19/2010 PM2.5 filter-based J.D. Smith, Sunrise Acres 

5/27/2010 PM2.5 filter-based Jean 

9/9/2010 PM2.5 filter-based Jean, J.D. Smith, Sunrise Acres 

10/16/2010 PM2.5 filter-based Sunrise Acres 

10/25/2010 PM2.5 filter-based Jean 

3/31/2010 CO East Sahara 

3/17/2010 CO Orr, Winterwood 

6/9/2010 CO J.D. Smith 

9/28/2010 CO Sunrise Acres 

3/10/2010 O3 Jean, Paul Meyer 

3/11/2010 O3 Lone Mountain, Palo Verde, Walter Johnson 

3/12/2010 O3 Apex 

4/22/2010 O3 Orr 

6/10/2010 O3 J.D. Smith 

6/22/2010 O3 Boulder City 

8/13/2010 O3 Boulder City 

9/15/2010 O3 Craig Road 

9/22/2010 O3 Mesquite 

10/27/2010 O3 Joe Neal 

12/6/2010 O3 Winterwood 

3/30/2010 NO2 Joe Neal 
67 

Date Pollutant Monitoring Stations

6/9/2010 NO2 J.D. Smith 

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

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

Speciation Network, DAQEM can move speciation sampling equipment anywhere in the county 

to support special project initiatives. Initial sampling took place at East Craig Road through April 

2010, and then sampling was moved to Jerome Mack to comply with NCore requirements. 
68 

16. National Performance Audits 

DAQEM participates in the Region 9-sponsored National Performance Audit Program (NPAP). 

This Through-the-Probe (TTP) performance evaluation, which focuses on gaseous criteria pollutants, is contracted and scheduled by Region 9. Audit results are immediately available. DAQEM 

received a “Pass” audit report for all TTP performance evaluations in 2010. 

The following table shows the 2010 TTP event schedule. 

Monitoring Station Pollutant TTP Conducted

Walter Johnson O3 4/12/2010 

Sunrise Acres, J.D. Smith CO, O3 4/13/2010 

J.D. Smith, Joe Neal O3, NO2 4/14/2010 

Each year, the PM2.5 FRM sampling network undergoes a Performance Evaluation Program 

(PEP) audit. Through EPA Region 9, an independent auditor is contracted to perform external 

field audits quarterly. The contractor submits evaluation results to the AQS database. Because of 

the manual methods used to audit FRM samplers, audit results (in μg/m3) are generated at some 

point after the audit. The point at which audit results are available varies. 

The following table summarizes 2010 PEP audit event activity. 

PM2.5 Sampler Location Date of PEP Audit

Sunrise Acres 2/16/2010 

J.D. Smith 4/29/2010 

J.D. Smith, Sunrise Acres 7/19/2010 

Sunrise Acres 11/10/2010 
69 

17. Network Modifications Completed in 2010 

The following table summarizes network changes made in 2010. 

Action Date Reason

Apex station closed. 

PM10 C-14, PM2.5 C-14, and O3 sampling 

terminated, though O3 and meteorological 

monitoring may occur during ozone season. 

September 2010 Budget and manpower constraints. 

E. Craig Road station closed. 

PM10, PM2.5, and O3 sampling terminated. 

Speciation sampling moved to NCore site 

(Jerome Mack). 

September 2010 Land lease issue, budget and manpower 

constraints. 

PM2.5 FRM sampler at J.D. Smith moved to 

NCore site (Jerome Mack). September 2010 PM2.5 FRM required at NCore. 

Jerome Mack site construction completed. 

Speciation samplers started operation. 

PM2.5 FRM sampler started operation. 

May 2010 

May 2010 

October 2010 

NCore site became operational for limited 

sampling. 

Lone Mountain site closed. 

O3 and PM10 monitoring terminated. 

April 2010 

Shelter safety concerns; budget and manpower constraints, redundancy with other 

ozone sites. 

East Sahara site closed. 

CO sampling terminated. 

April 2010 

Shelter safety concerns; budget and manpower constraints. NCore site activated as 

replacement. 

Mesquite site closed for normal operation. 

PM10 C-14 and O3 monitoring terminated, 

though O3 monitoring may occur during 

ozone season. 

September 2010 Land lease issue; budget and manpower 

constraints. 

Orr site closed. 

PM10 C-14, O3, and CO monitoring terminated. 

April 2010 Budget and manpower constraints. 
70 

18. Network Modifications Proposed 

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

next two years. The actions proposed constitute Clark County’s official approval request to EPA 

Region 9. 

 

Financial, technical, staffing, and regulatory challenges may require monitoring site and equipment terminations. In addition, logistical issues, e.g., expired leases, leases due to expire, and 

administrative challenges, may require DAQEM to terminate sites or equipment beyond what is 

specified in this plan. The following table lists proposed site and/or equipment terminations over 

the next two years. 

Site/Equipment Termination Date Explanation

PM2.5 FRM at Jean site. To be determined 

Anticipate continuous PM2.5 FEM deployment; 

Sunrise Acres has primary and collocated PM2.5

FRM for the network. 

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

Winterwood sites. To be determined No EPA requirement for CO monitoring. 

O3 monitoring at Winterwood and 

Boulder City sites. To be determined EPA requires only two sites for O3 monitoring. 

Apex and Jean sites. To be determined Unresolved lease issues. 

Additional site closures. To be determined Sites closed because of resource limitations. 

Note: ARM = Approved Regional Method. 

Termination Considerations 

PM2.5 FRM sampler at Jean site. In 2010, DAQEM maintained operations in the PM2.5 FRM filter-based network at a level that matched grant 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 the PM2.5 gravimetric laboratory, PM2.5 BAM operations, PM2.5 speciation sampling, PM2.5 FEM deployment, applicable NCore monitoring, and related training. The 

criteria in 40 CFR § 58.14(c)(3) may justify discontinuing filter-based PM2.5 FRM samplers altogether; in the future, DAQEM goals include replacing current non-designated PM2.5 BAMs with 

FEM-designated BAMs. Sunrise Acres has the primary and collocated PM2.5 FRM sampler for 

the network, so the FRM sampler at this site may no longer be needed. 

CO monitoring at J.D. Smith, Orr, and Winterwood sites. Compliance with 40 CFR § 58.14(c)(2) 

no longer requires CO monitoring at these locations. DAQEM will evaluate the CO data from 

these sites, along with SIP requirements, and may terminate CO monitoring at these sites to redirect program resources. DAQEM anticipates conducting near-road CO monitoring based on the 

newly proposed CO rule. 

O3 monitoring at Winterwood and Boulder City sites. 40 CFR § 58 requires operating two O3

monitoring sites. DAQEM will evaluate the O3 data from these sites, along with SIP requirements, and may terminate O3 monitoring at these sites to redirect program resources. Winterwood measures lower O3 readings in the Las Vegas Valley, and Boulder City may not be 
71 

sufficiently representative. DAQEM will continue to monitor and evaluate O3 in the urban core, 

high-concentration areas, background areas, and other areas to characterize transport patterns. 

Apex and Jean sites. These sites have lease or occupancy issues. DAQEM could be required to 

vacate with little or no notice, which would require terminating all monitoring operations. 

Additional Site Closures. Reductions in budget and staff or equipment failures may require 

DAQEM to consider further site closures in 2011. 

Proposed Installations and Considerations 

Apex. DAQEM plans to install a sonic detection and ranging 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 gaps and potential high pollutant sites. DAQEM has an interest in filling spatial monitoring gaps and monitoring 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, Sandy Valley, the north-central valley, 

the southwest valley, and Mt. Charleston have been identified for potential monitoring when resources allow. 

Collaboration. DAQEM may have opportunities to exchange information and data with other 

entities that monitor air quality, including the Las Vegas Paiute Tribe. DAQEM may also seek 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 to evaluate 

PM10 and O3 throughout Clark County. The system could move between various locations to assess air quality and help determine where to site permanent stations. Current resource limits will 

not support such a system, but DAQEM 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. Network Assessment (submitted June 30, 2010) 

2. PM10 Saturation Study (December 2005). 

3. Clark County Regional Ozone & Precursor Study (March 2006). 
72 

4. “Field Measurements and Documentation of Wildfire Event Air Quality Impacts during 

the 2009 and 2010 Summer Wildfire Season” (February 2011). 

5. Analysis to determine the O3 nonattainment boundary area (July 2004). 

6. Carbon Monoxide Saturation Study (April 2002), which confirmed that the network did

not miss any CO hot spots at that time. (DAQEM is reevaluating the CO network and 

considering site closures.) 

7. The EPA designation of the Thermo Electron FH62C14 PM2.5 BAM as an FEM and the 

potential for using the MetOne 1020 BAM as a designated PM2.5 FEM. 
73 

19. Status of Monitoring Site Leases 

The following table documents the status of leases for each monitoring site as of May 2011. Expired leases or related events may result in the closure of a particular monitoring station or site. 

This plan constitutes Clark County’s official request to EPA Region 9 to discontinue monitoring 

under these or similar circumstances. 

Site Agreements

Site Documentation Owner Terms

Boulder City: 

1 air quality monitoring 

station, 1 met site (decommissioned) 

2 agreements Boulder City and 

CCSD 

11/30/15 

3/1/16

Green Valley Agreement City of 

Henderson 3/2/12 

J.D. Smith MOU CCSD 3/1/16 

Joe Neal MOU CCSD 3/1/16 

Mesquite Grant of easement Alcarza Family Trust 4/30/21 

NLV Airport Agreement Clark County Dept. of 

Aviation 10/19/15 

Orr MOU CCSD 3/1/16 

Palo Verde MOU CCSD 3/1/16 

Paul Meyer Agreement Clark County 4/14/14 

Sunrise Acres MOU CCSD 3/1/16 

Walter Johnson MOU CCSD 3/1/16 

Winterwood MOU Clark County 6/30/25 

Continuing Site Access Issues*

Site Documentation Owner Terms

Apex 

Local Stationary 

Source; Land use Under Review 

City Center NDOT 

E. Craig Road L&M Holding 

Jean BLM and Las Vegas 

Valley Water District 

Lone Mountain 

Las Vegas 

Valley Water 

District 

NOTE: BLM = U.S. Bureau of Land Management; CCSD = Clark County School District; MOU = Memorandum of Understanding; NDOT = Nevada Department of 

Transportation; ROW = right-of-way. 

*Agreements for these sites are under review; however, we may have to abandon these sites with little to no notice.
74 

20. 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 

Jerome Mack PM2.5 FRM Neighborhood Population exposure 

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 
75 

Site Monitor Measurement Scale Monitor Objective Type 

Paul Meyer O3 Neighborhood Population exposure 

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 
76 

21. Receptor-Measured Criteria Pollutant Trends 

The following pages contain plots of criteria pollutant measurements. In general, all pollutants 

have declined over the years. 

Figure 27 – 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 2010

High 8-Hour Average 

Concentration (ppm) 

Year

E. Flamingo / Orr E. Sahara J.D. Smith

Sunrise Acres Winterwood

EPA 8-Hour 
77 

Figure 28 – O3 Trends 

0.000

0.010

0.020

0.030

0.040

0.050

0.060

0.070

0.080

0.090

0.100

0.110

0.120

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

Ozone (PPM)

DAQEM Ozone Fourth High Eight Hour Average

SE

CC

CR

FL

AP

MQ

PM

WJ

LO

PV
Figure 29 – SO2 Trends 

0

20

40

60

80

1998 1999 2000

SO2 One Hour High

Concentration (ppb)

EPA 1 Hour Standard 75 ppb

78 

2001 2002 2003 2004 2005 2006 2007 2008

E. Sahara
79 

Figure 30 – 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 2010

Annual Mean (ppb)

Year

Apex

J.D. Smith

Jean

E. Sahara

Palo Verde

Joe Neal

EPA Annual 

Standard 
80 

Figure 31 – 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 2010

Annual Mean (μg/M3

)

PM10

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
81 

Figure 32 – Filter-Based PM2.5 FRM Trends 

0

5

10

15

20

25

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

Annual Mean (μg/M3

)

Year

J. D. Smith E. Charleston/ Sunrise Acres

Jean Jerome Mack

EPA Annual 
82 

Figure 33 – Continuous PM2.5 Annual Mean Trends 

0

5

10

15

20

25

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

Annual Mean (μg/M3

)

Year

Craig Road Green Valley J. D. Smith

Sunrise Acres Apex Jean
83 

Figure 34 – 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 2010

Annual Mean (μg/M3

)

Year

J.D. Smith 

FRM

J.D. Smith 

BAM

Sunrise Acres 

FRM

Sunrise Acres 

BAM

Jean FRM

Jean BAM
84 

22. Pollen Network 

The pollen network, which was separate from the NAAQS network, was a unique local service 

DAQEM provided to Clark County residents that ended in 2010. It is included in this report for 

DAQEM use and future reference. 

The two primary producers of allergens in Clark County are the fruitless mulberry, which pollinates in March, and the European olive, which pollinates in April. Clark County banned further 

planting of these trees (except certified low-pollinating varieties) because of their high levels of 

pollen (see Section 44 of the Clark County Air Quality Regulations). 

DAQEM operated nine pollen monitoring stations in Clark County during 2010, using the Multidata Model 40 rotorod sampler at each site. The pollen network was located primarily in residential areas, and was intended to assess the general population’s pollen exposure levels. Data were 

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

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

days a week. The following map depicts the pollen network in 2010. 

The pollen monitoring network was dynamic, and monitoring locations changed depending on 

valley growth, pollen levels, and public requests. However, Clark County terminated pollen 

monitoring in October 2010 due to resource constraints and reduced staffing levels. 
85 

Figure 35 – Pollen Sampling Locations in Las Vegas and Boulder City