# C l a r k C o u n t y

D e p a r t m e n t o f A i r Q u a l i t y & E n v i r o n m e n t a l M a n a g e m e n t

A n n u a l N e t w o r k P l a n R e p o r t

J u n e 2 0 1 1ii



### Executive Summary

This annual plan reports the status of the Clark Co unty air monitoring network operated by its Department of Air Quality and Environmental Managem ent (DAQEM). Reporting standards are outlined in Title 40, Part 58 of the Code of Federa l 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 quali ty, and ways in which the information recorded by the network is disseminated.

The 2010 network review identified potential defici encies 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 networ k 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 monito ring requirements on January 26, 2011; revised the National Ambient Air Quality Standard (NA AQS) for sulfur dioxide (SO 2 ) on June 2, 2010; and revised the NAAQS for nitrogen dioxide (N O 2 ) on January 22, 2010. The EPA requirement to operate a National Core Monitoring Net work (NCore) station is discussed in this report. In addition, this plan includes a discussio n of the regulation changes that affect Clark County and its compliance status.iii



### 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 Databa se ................................................ ...... 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 ....................................

................................................... .......................... 84iv



### 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 – O 3 Monitors .........................................

................................................... ....................56 Figure 23 – NO x Monitors .........................................

................................................... .................57 Figure 24 – Continuous PM 10 Monitors.......................................... ...............................................58 Figure 25 – Continuous PM 2.5 Monitors ......................................... ...............................................59 Figure 26 – Filter-Based PM 2.5 Monitors.......................................... .............................................60 Figure 27 – Carbon Monoxide Trends ................

................................................... ........................76 Figure 28 – O 3 Trends ...........................................

................................................... ......................77 Figure 29 – SO 2 Trends............................................

................................................... ...................78 Figure 30 – NO 2 Trends ...........................................

................................................... ...................79 Figure 31 – Continuous PM 10 Trends ........................................... .................................................80 Figure 32 – Filter-Based PM 2.5 FRM Trends ....................................... ..........................................81 Figure 33 – Continuous PM 2.5 Annual Mean Trends................................ .....................................82 Figure 34 – Continuous vs. Filter-Based PM 2.5 Trends ........................................... ......................83 Figure 35 – Pollen Sampling Locations in Las Vegas and Boulder City .................................. ....85v 

### 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 & Envi ronmental 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 NO 2 nitrogen dioxide NO x nitrogen oxide O 3 ozone Pb lead PM 2.5 particulate matter 2.5 microns or less in aerodyna mic diameter PM 10 particulate matter 10 microns or less in aerodynam ic diameter ppm parts per million SO 2 sulfur dioxide1



### 1. Introduction

This document is a review of the Clark County Depar tment of Air Quality and Environmental Management (DAQEM) air monitoring network, and serv es 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 met hodology. 3. Description of monitoring instruments in the networ k 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 (PM 2.5 ) meets design value standards. 7. Identification of any ozone (O 3 ) monitoring site that exceeds the 2010 design valu e 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 a mbient concentrations of the following criteria pollutants: PM 2.5, PM 10 , O 3 , carbon monoxide (CO), and nitrogen oxides (NO, NO 2 , NO x ). 2. DAQEM operated visibility instrumentation, includin g 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 objective s:

a. Ensure that the network is monitoring representativ e data, and that geographical and population factors are considered in managing the n etwork. b. Make monitoring data readily accessible to the U.S. Environmental Protection Agency (EPA), regional and national air quality agencie s, the general public, and stakeholders.

c. Monitor visibility using long-path visibility techn ology and visibility cameras. d. Review analyzer placement for O 3 boundaries, considering formation and transport.

e. Improve forecasting methods for O 3 , PM 10 , and PM 2.5
. f. Make efforts to update and maintain monitoring equi pment. 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) sit e.2

5. Parts of Clark County are designated nonattainment for two criteria pollutants: PM 10 in Hydrographic Area (HA) 212, and O 3 in HAs 164A, 164B, 165, 166, 167, 212, 213, 214, 216, 217, and 218.

a. The Las Vegas Valley (HA 212) was designated nonatt ainment for PM 10 in the late 1980s, and in 1993 it was reclassified as “serious” nonattainment under the 1990 National Ambient Air Quality Standards (NAAQS) for PM 10 . Since the end of 2006, however, Clark County has maintained compliance wit h the 1990 PM 10 NAAQS. DAQEM is now developing a PM 10 Request for Redesignation and Maintenance Plan for submittal to EPA in the summer of 2011. In addi tion, exceptional event demonstration packages have been submitted to EPA for on e PM 10 exceedance in 2007 (not flagged, not deemed questionable data) and two in 2 008. b. In April 2004, parts of Clark County were designate d nonattainment for the 1997 O 3 NAAQS. Based on 2008-2010 monitoring data, Clark Co unty has been in compliance with the 1997 O 3 NAAQS. DAQEM submitted an Ozone Request for Redesignation and Maintenance Plan to EPA.

c. The Las Vegas Valley was designated “moderate” nona ttainment for the 1990 CO NAAQS in 1997, and in 2000 redesignated “serious” n onattainment. In June 2005, EPA determined that the Las Vegas Valley had attain ed the 1990 CO NAAQS by the applicable date of December 31, 2000, making the ar ea eligible to submit a request for redesignation to attainment status. In 2008, DA QEM prepared and submitted the CO Request for Redesignation and Maintenance Plan , which EPA approved in September 2010. Clark County is thus currently designa ted a maintenance area for CO. d. Clark County is in attainment or unclassifiable for PM 2.5 , NO 2 , lead (Pb), and sulfur dioxide (SO 2 ).3

Below is a picture of the Engineering Division, whi ch includes the Air Quality Monitoring and Quality Assurance Team. From left to right: Christi an Francis, Management Analyst II; Mickey Palmer, Senior Air Quality Monitoring Technician; P ravin Pema, Air Quality Monitoring Technician II; Matt Nelson, Air Quality Monitoring Tech nician II; Mike Sword, Air Quality Engineering Manager; Mickey Turner, Senior Air Quality Monitoring Technician; Yousaf Hameed, Air Quality Monitoring Supervisor; David Dickens, A ir Quality Monitoring Technician II; Brandon Cunningham, Senior Management Analyst; Phil Wik er, Senior Air Quality Monitoring Technician; Kris Simonian, Air Quality Monitoring T echnician 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 writ ten, 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, da ta 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 networ k. 5. Reviewed National Weather Service climate resources

. 6. Studied traffic count reports prepared by the Nevad a Department of Transportation. 7. Reviewed lease agreements. 8. Calculated design values for O 3 and PM 2.5
.5



### 3. Metropolitan Statistical Area

Clark County qualifies as one Metropolitan Statisti cal Area (40 CFR § 81). The Las Vegas Valley contains the majority of the population for Cla rk County; smaller communities, such as the Cities of Mesquite and Boulder City, do not qualify as Metropolitan Statistical Areas.6



### 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 so uthern Nevada. Mountains surrounding the valley extend 2,000 to 10,000 feet above the valley fl oor. The Las Vegas Valley comprises about 600 square miles and runs from northwest to southea st. 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 easter n rim of the valley, including the Muddy Mountains, the Black Mountains, and the Eldorado Ra nge. For most of the Las Vegas metropolitan area, the valley floor slopes downward from wes t to east. This affects local climatology by driving variations in wind, precipitation, and stor m 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), sev en miles south of downtown Las Vegas.

General Climatic Summary

The four seasons are actually well defined in Las V egas, 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 tempere d somewhat by the extremely low relative humidity; howeve r, 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 t he development of spectacular desert thunderstorms associated with significant flash floodin g 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 r ainfall in Las Vegas, but in general, the Sierra Nevada Mountains of eastern California and the Spri ng Mountains immediately west of the Las Vegas Valley act as effective barriers to moisture.

Snow accumulation is rare in Las Vegas. Flurries ar e observed once or twice during most winters, but snowfall of an inch or more occurs only o nce every four to five years. However, freezing temperatures occur regularly each year: the val ley has a 30-year average of 24 days with low temperatures at or below 32 ° . Snowfall is common in the mountains surrounding L as Vegas, with the Spring Mountains receiving between 5 and 1 0 feet annually. The spring and fall seasons are generally considered ideal. Although sharp temp erature 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 s torms. Winter and spring wind events often7

generate widespread areas of blowing dust and sand. Strong wind episodes in the summertime are usually connected with thunderstorms, and are t hus isolated and localized. Prevailing wind direction is typically either southwest or north un less associated with a thunderstorm outflow.

Regional transport and local influences produce hig her O 3 concentrations on the west and northwest sides of the valley. O 3 episodes in the Las Vegas Valley are generally cha racterized by a surface (thermal) low pressure system extending ove r Arizona, southern California, and Nevada; ridging of 500 millibars (mb) over the southwest orcentral United States; and southwesterly surface flow during the afternoon hours, accompanied b y ample sunshine and high temperatures. Superimposed on the synoptic-scale meteorological c onditions are local, terrain-induced mesoscale meteorological features. Together, these deter mine 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 t he 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 souther n Nevada is enveloped by a thermal lowpressure system.8

Figure 1 – Topographic Map9



### 5. Ambient Air Quality Monitoring Methodology

DAQEM operated 16 monitoring stations in Clark Coun ty 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 p ollution transport and background levels, contains subnetworks for the EPA criteria pollutant s PM 10 , PM 2.5 , CO, O 3 , and NO 2 .

Continuous Particulate Matter Monitors

The sampling method employs the continuous Thermo E lectron FH62C14 series monitor, which uses carbon-14 as the beta source. All continuous P M 2.5 monitors have a Very Sharp Cut Cyclone (VSCC) as their second stage separator.

Particulate Matter of 10 Microns or Less

DAQEM operated 13 continuous PM 10 monitors in Clark County in 2010, nine inside the Las Vegas Valley and four outside it. The map in the se ction “Continuous PM 10 Monitoring Locations in 2010” shows the locations of the monitors in the PM 10 monitoring network (Figure 23).

A quality control (QC) flow rate verification is co nducted on the continuous PM 10 monitors every two weeks, exceeding the EPA requirement of o nce per month. A QA flow rate audit is conducted on the monitors once every six months.

The following table shows the spatial scale and mon itoring objective for each PM 10 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 PM 2.5 monitors in Clark County. The map in the section titled “Continuous PM 2.5 Monitoring Locations in 2010” shows the locations of the monitors in the continuous PM 2.5 monitoring network (Figure 24).

In accordance with 40 CFR § 58.30, DAQEM has determ ined that all PM 2.5 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 con tinuous PM 2.5 monitors every two weeks, exceeding EPA requirements. A QA flow rate audit is c onducted on the monitors once every six months.

The following table shows the spatial scale and mon itoring objective for each PM 2.5 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 PM 2.5 federal reference method (FRM) and PM 2.5 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 th e section “Filter-Based PM 2.5 Monitoring Locations in 2010” shows the locations of the s amplers in the PM 2.5 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 PM 2.5 FRM filters.

Particulate Matter of 2.5 Microns or Less

The following table lists the four filter-based PM 2.5 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 fil ter-based PM 2.5 FRM samplers once a month, and a QA flow rate audit is conducted on the sample rs once every six months.11

The following table shows the spatial scale and mon itoring objective for each routine filter-based PM 2.5 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 notif y the public if a PM 2.5 monitor exceeds the NAAQS or if a community monitoring zone (as def ined in 40 CFR § 58.10 (8)(c)) is created or changed. DAQEM will notify the community of a pr oposed zone change by (1) posting a review of the PM 2.5 monitoring network to its Web site with the change s being considered, and (2) soliciting feedback from the community. DAQEM will consider and respond to all public comments before making changes to the PM 2.5 network. Exceptions to the review process will be made only for a lost lease or a notice from the pro perty owner to vacate a site.

40 CFR § 58.30(a)(1) states that samples from certa in types of microscale sites are unsuitable for comparison to the annual PM 2.5 NAAQS. DAQEM does not operate a microscale PM 2.5 site, so all its PM 2.5 samples are suitable for NAAQS comparisons.

Speciation

DAQEM operated a SASS speciation sampler in conjunc tion 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). Speciatio n sampling occurs on a one-in-three day schedule, which is the same schedule as the PM 2.5 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 filt er correlation. The map in the section “Carbon Monoxide Monitoring Locations in 2010” show s the locations of the monitors in the CO monitoring network (Figure 20).

DAQEM conducts a three-point QC check on the CO mon itors every week and calibrates them quarterly. Twenty-five percent of the monitors unde rgo a QA audit every quarter, and all are audited at least once a year.

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

Site Spatial Scale Objective Sunrise Acres Neighborhood Highest concentration
All others Neighborhood Population exposure12

Ozone

In 2010, DAQEM operated 17 API 400 Series ultraviol et absorption O 3 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 “O 3 Monitoring Locations in 2010” shows the locations of the monitors in the O 3 monitoring network (Figure 21). The network was or iginally designed for comparison to the one-hour O 3 NAAQS, but was modified to calculate eight-hour (rolling average) values when EPA changed the stand ard in 1997.

DAQEM’s O 3 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 fr om consumer products.

• Establishment of upper-air wind measurements in Cla rk County.

• Characterization of 2009 wildfire impacts on air qu ality in Clark County.

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

DAQEM is planning another wildfire study in the sum mer of 2011 to evaluate how transport and ozone at upper altitudes affects O 3 levels, and O 3 formation in Clark County. These studies should contribute to a better understanding of O 3 transport impacts and more thorough exceptional event demonstrations.

DAQEM conducts a three-point QC check on O 3 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 mon itoring objective for each O 3 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 NO x monitors with gas phase chemiluminescence inside the Las Vegas Valley. The map in the s ection “Nitrogen Oxides Monitoring Locations in 2010” shows the locations of monitors in t he NO x monitoring network (Figure 22).

DAQEM conducts a three-point QC check on the NO x monitors every week and calibrates them quarterly. Twenty-five percent of the monitors unde rgo a QA audit every quarter, and all are audited at least once a year.13

The following table shows the spatial scale and mon itoring objective for each NO x monitor.

Site Spatial Scale Objective J.D. Smith Neighborhood Highest concentration Joe Neal Neighborhood Population exposure14



### 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 correcti ng 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/O 3 Monitor data for impacts from cooling tower. 2011

Obstacle distance Green Valley/PM 2.5 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 C FR § 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.15



### 7. Design Values for 2010

The following table compares O 3 design values with the NAAQS standard.

Station O 3 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 PM 2.5 design values with the NAAQS standard.

Station PM 2.5 Design Value ( μ g/m3) NAAQS Standard ( μ g/m3)
Sunrise Acres 8.5 15
Jean 3.9 15 J.D. Smith 7.8 15

Note: μ g/m3 = micrograms per meter cubed.

The following table compares 24-hour PM 2.5 design values with the NAAQS standard.

Station PM 2.5 Design Value ( μ g/m3) NAAQS Standard ( μ g/m3)
Sunrise Acres 21 35
Jean 11 35 J.D. Smith 17 35

40 CFR § 58.30(a)(1) states that samples from certa in types of microscale sites are unsuitable for comparison to the annual PM 2.5 NAAQS. DAQEM does not operate a microscale PM 2.5 site, so all its FRM PM 2.5 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 emission s from nearby gravel processing and power plants. Since the site is generally downwind from L as 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 V egas was established at the request of Boulder City government of ficials and residents to serve as an indicator of population exposure to pollutants, particularly O 3 and PM 10 . This monitoring site is in operation to serve as an indicator of population exposur e for pollutants.

Craig Road (32-003-0020). This site in the City of North Las Vegas was establ ished to comply with a source’s permit conditions related to potent ially high emissions of O 3 precursors. Although that source no longer exists, the site conti nues to monitor O 3 , PM 10 , and PM 2.5 . Although, in the past it has periodically exceeded the PM 10 24-hour standard, this site has not experienced a PM 10 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 processi ng plant, and continues to monitor PM 10 and PM 2.5
. J.D. Smith (32-003-2000). This site in North Las Vegas replaced the old McDan iel and Post Office PM sites. It monitors gaseous (NO x , CO, and O 3 ) and particulate (PM 10 and PM 2.5 ) 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 souther n California; O 3 , PM 10 , and continuous and filter-based PM 2.5 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 PM 2.5 , PM coarse, and speciated PM parameters), and mete orological parameters as part of the nationwide network. Because of NCore require ments, 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 La s Vegas are to monitor O 3 and its precursors in an area of high concentratio ns and to support DAQEM modeling efforts. The topography is such that the summertime l oft brings higher O 3 and precursor levels toward this site from the east end of the Las Vegas Valley. The primary reason for this installation was to monitor O 3 precursors in a high O 3 concentration area, and to support DAQEM modeling efforts. PM 10 was initially deployed at this site due to populat ion growth in this part of the17

valley; this site continues to serve as a high O 3 indicator for the Las Vegas Valley. A NO x monitor was added in January 2008.

Lone Mountain (32-003-0072) . The primary objective of this site in northwest L as Vegas is to monitor O 3 . The topography is such that the summertime loft b rings higher O 3 and precursor levels toward this site from the east end of the Las Vegas Valley. PM 10 Monitoring was initiated in 1998 because of gravel processing to the west/north west 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 t o 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 SO 2 , CO, & O 3 . Mesquite (32-003-0023). This site approximately 70 miles north of Las Vegas monitors O 3 and PM 10 . It sits along a transport and exit corridor for j urisdictional boundaries, and serves as an indicator of population exposure to pollutants.

Orr (32-003-1021). This replaced the East Flamingo site, which was ter minated because the lease was lost and it was too close to the road to meet its O 3 monitoring objective. DAQEM began monitoring O 3 at Orr in April 2006, and continues monitoring CO and PM 10 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 O 3 , although PM 10 is also monitored here. The topography is such tha t the summertime loft brings higher O 3 and precursor levels toward this site from the eas t end of the Las Vegas Valley.

Palo Verde (32-003-0073). The primary objective of this site in west Las Vega s is to monitor O 3, although PM 10 is also monitored here. The topography is such tha t the summertime loft brings higher O 3 and precursor levels toward this site from the eas t end of the Las Vegas Valley.

Sunrise Acres (32-003-0561). Monitoring at this site near the center of the Las Vegas Valle y began as part of a CO study in the 1990s, and its pri mary 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 PM 10 and PM 2.5 using both filter-based and continuous methodologi es, and serves as the primary and collocated sampling site for PM 2.5 FRM samplers.

Walter Johnson (32-003-0071). The primary objective of this site on the west side of Las Vegas is to monitor O 3 . The topography is such that the summertime loft b rings high O 3 and precursor levels towards this site from the east end of the L as Vegas Valley.

Winterwood (32-003-0538). This site on the east side of Las Vegas is one of D AQEM’s oldest sites. Its primary objective is to monitor CO and O 3 , but it also serves as an indicator of population exposure to pollutants.

No DAQEM monitoring site is located near furnaces o r incinerators.18

Instrument Information

Items monitored: 1. CO. 2. O 3 . 3. NO x . 4. PM 10 continuous. 5. PM 2.5 continuous. 6. PM 2.5 FRM (manual method). 7. PM 2.5 species (manual method). 8. Visibility. 9. Meteorological parameters.

Monitor type: 1. CO: gas filter correlation (non-dispersive infrared ). 2. O 3 : ultraviolet absorption. 3. NO x : chemiluminescent gas phase reaction of NO x and O 3 . 4. PM 10 and PM 2.5 C-14 continuous monitor: Beta Attenuation Monitor (BAM). 5. PM 2.5 RAAS manual method: filter-based. 6. PM 2.5 Speciation Air Sampling System (SASS) and URG manua l 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 O 3 API 400 Series X Yes
NO 2 API 200 Series X Yes
PM 10 Thermo Electron C14 X Yes
PM 2.5 Thermo Electron C14 X No
PM 2.5 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 meteorol ogical tower equipped with an ultrasonic wind speed/wind direction sensor and an ambient tem perature 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 Databa se

The following table shows monitoring start dates in AQS.

Site Name Site ID Parameter Description AQS Parameter Code POC Date Sampling Began Apex 0022 NO 2 42602 1 01-Jan-1998 Apex 0022 O 3 44201 1 01-Jan-1998 Apex 0022 PM 10 total 0-10 μ m STP 1 81102 1 01-Jan-1998 Apex 0022 PM 2.5 - local conditions C-14 88502 3 23-Jan-2007 Boulder City 0601 O 3 44201 1 01-Jul-1998 Boulder City 0601 PM 10 total 0-10 μ m STP 81102 1 01-Jan-1998 E. Craig Road 0020 O 3 44201 1 01-Jan-1992 E. Craig Road 0020 PM 10 total 0-10 μ m STP 81102 1 01-Jan-1998 E. Craig Road 0020 PM 2.5 - local conditions C-14 88101 3 01-Jan-2003 E. Craig Road 0020 PM 2.5 - speciation 88101 5 01-Jan-2007
E. Sahara 0539 CO 42101 1 01-Jan-1998
E. Sahara 0539 SO 2 42401 1 01-Jan-1998
E. Sahara 0539 NO 2 42602 1 01-Jan-1998
E. Sahara 0539 PM 10 total 0-10 μ m STP 81102 1 01-Jan-1995 Green Valley 0298 PM 10 total 0-10 μ m STP 81102 1 01-Jan-1998 Green Valley 0298 PM 2.5 - local conditions C-14 88101 3 01-Jan-2003
J.D. Smith 2002 NO 2 42602 1 01-Oct-1998
J.D. Smith 2002 CO 42101 1 01-Oct-1998
J.D. Smith 2002 O 3 44201 1 01-Oct-1998
J.D. Smith 2002 PM 10 total 0-10 μ m STP 81102 1 01-Jan-1998
J.D. Smith 2002 PM 2.5 - local conditions 88101 1 01-Jan-1999
J.D. Smith 2002 PM 2.5 - local conditions C-14 88502 3 01-Jan-2003
Jean 1019 O 3 44201 1 01-Aug-1998
Jean 1019 PM 10 total 0-10 μ m STP 81102 1 01-Jan-1995
Jean 1019 PM 2.5 - local conditions 88101 1 01-Jan-1999
Jean 1019 PM 2.5 - local conditions C-14 88502 3 26-May-2007
Jerome Mack 0540 PM 2.5 - speciation 88101 5 01-May-2010
Jerome Mack 0540 PM 2.5 - local conditions 88101 1 01-Oct-2010
Joe Neal 0075 O 3 44201 1 01-Jul-2000
Joe Neal 0075 PM 10 total 0-10 μ m STP 81102 1 01-Jan-2001
Joe Neal 0075 NO 2 42602 1 01-Jan-2008
Lone Mountain 0072 O 3 44201 1 01-Jan-1998
Lone Mountain 0072 PM 10 total 0-10 μ m STP 81102 1 01-Jan-1998 Mesquite 0023 NO 2 42602 1 01-Nov-2001 Mesquite 0023 O 3 44201 1 01-Oct-2001 Mesquite 0023 PM 10 total 0-10 μ m STP 81102 1 01-Nov-2001
Orr 1021 CO 42101 1 01-Oct-200220 Site Name Site ID Parameter Description AQS Parameter Code POC Date Sampling Began
Orr 1021 O 3 44201 1 01-Apr-2006
Orr 1021 PM 10 total 0-10 μ m STP 81102 1 01-Oct-2002
Palo Verde 0073 NO 2 42602 1 01-Aug-1998
Palo Verde 0073 O 3 44201 1 01-Jul-1998
Palo Verde 0073 PM 10 total 0-10 μm STP 81102 1 01-Jul-1998 Paul Meyer Park 0043 O 3 44201 1 01-Jul-1998 Paul Meyer Park 0043 PM 10 total 0-10 μm STP 81102 1 01-Jan-1998
Sunrise Acres 0561 CO 42101 1 01-Oct-1996
Sunrise Acres 0561 PM 10 total 0-10 μ m STP 81102 1 17-Apr-2004
Sunrise Acres 0561 PM 2.5 - local conditions 88101 1 14-Apr-2004
Sunrise Acres 0561 PM 2.5 - local conditions 88101 2 14-Apr-2004
Sunrise Acres 0561 PM 2.5 - local conditions C-14 88101 3 01-Jul-2005
Walter Johnson 0071 O 3 44201 1 01-Aug-1998
Walter Johnson 0071 PM 10 total 0-10 μ m STP 81102 1 01-Jul-1995
Winterwood 0538 CO 42101 1 01-Jan-1998
Winterwood 0538 O 3 44201 2 01-Jul-1979

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



### 10. Monitoring Site Traffic Count Summary

The following table provides traffic count informat ion near monitoring sites.

Site Name Distance to Nearest Roadway 1 Traffic Study Counts from Nearest Roadway 2 Traffic Counts Estimated by Operator Maximum Traffic

Counts for Distance to Roadway

3 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 20,000/15,00 0 E. Sahara 48 m to Sahara 25,000 20,000/20,000 Green Valley 12.2 m to Santiago 3,900 10,000/10,0 00 J.D. Smith 180 m to Bruce 8,500 70,000/60,000 Jean 1287 m to State Hwy. 161 1,700 110,000/60,00 0 Jerome Mack 484 m to Lamb 30,000 70,000/60,000 Joe Neal 12.2 m to Rebecca Not available 4,200 10,0 00/10,000 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 10,000/10,0 00 Palo Verde 14.7 m to Pavilion Not available 7,800 1 0,000/10,000 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 4 00 20,000/15,000

1 Distance from monitoring path to edge of roadway.
2 Traffic study counts taken or derived from nearest study performed by the Nevada Department of Transpo rtation.
3 Tables E-1 & E-2 in 40 CFR § 58, Appendix E, are us ed to determine the minimum and maximum distance fr om the edge of the roadway to the monitoring path or probe. Table E-1 = O 3 and NO 2 for urban and neighborhood scale; Table E-2 = CO f or 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 Airport23

Figure 2 – Apex

Type: SLAMS Apex (AP) (32-003-0022) Location: 12101 U.S. Highway 93, Las Vegas, NV 8903 0 Closest Roads: I-15, U.S. Highway 93 Universal Transverse Mercator (UTM) X-Coordinate: 6 67652.800; UTM Y-Coordinate: 4004823.000 Operative Schedule: 24 hours Sampling Methods: O 3 : Ultraviolet Absorption, API 400 PM 10 : Beta Attenuation, Thermo Electron FH62C14 PM 2.5 : Beta Attenuation, Thermo Electron FH62C14 Predominant Wind Direction: South Photograph Direction: South

PM 10 PM 2.5 Continuous O 3 Spatial scale Regional Regional Regional Monitoring objective Source-oriented General/Backgr ound 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 m24 PM 10 PM 2.5 Continuous O 3 Obstructions on roof None None — Obstacle distance None None None
Probe material — — Teflon
Residence time — — 1.9 s25

Figure 3 – Boulder City

Type: SLAMS Boulder City (BC) (32-003-0601) Location: 1005 Industrial Rd., Boulder City, NV 890 05 Closest Roads: U.S. Hwy. 93, Industrial Rd. UTM X-Coordinate: 694175.800; UTM Y-Coordinate: 398 3670.000 Operative Schedule: 24 hours Sampling Methods: O 3 : Ultraviolet Absorption, API 400E PM 10 : Beta Attenuation, Thermo Electron FH62C14 Predominant Wind Direction: Southwest Photograph Direction: Northwest

PM 10 O 3 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 s26

Figure 4 – East Craig Road

Type: SLAMS E. Craig Rd (CR) (32-003-0020) Location: 4701 Mitchell St., North Las Vegas, NV 89 081 Three Closest Roads: N. Walnut Rd., E. Craig Rd., M itchell St. UTM X-Coordinate: 671333.900; UTM Y-Coordinate: 401 2829.000 Operative Schedule: 24 hours Sampling Methods: O 3 : Ultraviolet Absorption, API 400A PM 2.5 : Beta Attenuation, Thermo Electron FH62C14 PM 10 : Beta Attenuation, Thermo Electron FH62C14 PM 2.5 : Speciation, MetOne SASS and URG 3000 Predominant Wind Direction: South Photograph Direction: West

PM 10 O 3 Speciation PM 2.5 Continuous Spatial scale Neighborhood Neighborhood Neighborhoo d 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 3 4.0 m
Distance between collocated monitors 1.5 m — 1.9 m 1.5 m27 PM 10 O 3 Speciation PM 2.5 Continuous Ground cover Paved, unpaved — Paved, unpaved Paved, unpavedSpacing 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: 400 1593.000 Operative Schedule: 24 hours Sampling Method: CO: Gas Filter Correlation API 300 E Predominant Wind Direction: Southwest Photograph Direction: East Changes: Moved to Jerome Mack Middle School; new sh elter; 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 s30

Figure 6 – Green Valley

Type: SLAMS Green Valley (GV) (32-003-0298) Location: 298 Arroyo Grande Blvd., Henderson, NV 89 014 Three Closest Roads: Arroyo Grande Blvd., Santiago Dr., N. Stephanie St. UTM X-Coordinate: 675390.700; UTM Y-Coordinate: 399 1108.000 Operative Schedule: 24 hours Sampling Methods: PM 2.5 : Beta Attenuation, Thermo Electron FH62C14 PM 10 : Beta Attenuation, Thermo Electron FH62C14 Predominant Wind Direction: Southwest Photograph Direction: Southeast

PM 10 PM 2.5 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 PM 10 PM 2.5 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 8 9030 Three Closest Roads: E. Owens Ave., N. Bruce St., E . Lake Mead Blvd. UTM X-Coordinate: 668778.300; UTM Y-Coordinate: 400 6793.000 Operative Schedule: 24 hours Sampling Methods: O 3 : Ultraviolet Absorption, API 400A CO: Gas Filter Correlation Analyzer, API 300E PM 10 : Beta Attenuation, Thermo Electron FH62C14 PM 2.5 : Beta Attenuation, Thermo Electron FH62C14 PM 2.5 : Andersen RAAS2.5-300 FRM NO 2 : Gas Phase Chemiluminescence, API 200E Predominant Wind Direction: Southwest Photograph Direction: North

PM 10 CO PM 2.5 (FRM) NO 2 O 3 PM 2.5 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

PM 10 CO PM 2.5 (FRM) NO 2 O 3 PM 2.5 Continuous Spacing from trees 35 m 32.8 m 35 m 32.8 m 32.8 m 3 5 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: 396 1425.000 Operative Schedule: 24 hours Sampling Methods: O 3 : Ultraviolet Absorption, API 400E PM 10 : Beta Attenuation, Thermo Electron FH62C14 PM 2.5 : Beta Attenuation, Thermo Electron FH62C14 PM 2.5 : Andersen RAAS2.5-300 FRM Predominant Wind Direction: Southwest Photograph Direction: Southwest

PM 10 PM 2.5 Continuous O 3 PM 2.5 (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 m35

PM 10 PM 2.5 Continuous O 3 PM 2.5 (FRM)

Distance between collocated monitors 2.7 m 2.7 m — 10 m
Ground cover Native desert, gravel Native desert, g ravel — Native desert, gravelSpacing 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’ elev ation Three Closest Roads: Lamb, Nellis, and East Sahara UTM X-Coordinate:36.138467; UTM Y-Coordinate: 115.0 73854 Operative Schedule: 24 hours Sampling Methods: SO 2 : TAPI 100E NO x : TAPI 200EU Nitrogen compounds: TAPI 501Y CO: TAPI 300EU O 3 : Ultraviolet Absorption, API 400E Chemical speciation: Met One Instruments SASS Reference Ambient Air Sampler: Andersen Instruments PM2.5-300 PM 10 , PM 2.5 , and PM 10-2.5 : MetOne BAM 1020 Pair Chemical Carbon: Sequential Particulate Speciation System: URG-3000N Predominant Wind Direction: South (light and variab le) Photograph Direction: Southwest37PM10ContinuousPM2.5ContinuousPM10-2.5ContinuousPM2.5(FRM)SpeciationSASSSpeciationURGO3NOYTrace CO Trace SO2Spatial scale — — — Neighborhood Neighborhood NeighborhoodNeighborhoodUrban NeighborhoodUrbanMonitoringobjective— — —PopulationexposurePopulationexposurePopulationexposurePopulationexposurePopulationexposurePopulationexposurePopulationexposureVertical probeplacement— — — 2.1 m 1.6 m 1.8 m 12.8 m 13.6 m 12.8 m 12.8 mUnrestrictedairflow— — — 360° 360° 360° 360° 360° 360° 360°Spacing from trees — — — 25 m 25 m 25 m 18 m 19 m 18 m 18 mSpacing fromstation to road— — — 482 m 482 m 482 m 482 m 482 m 482 m 482 mDistance betweencollocated monitors— — — — 2.3 m 2.3 m — — — —Ground cover — — —Concrete/grassConcrete/grassConcrete/grassGrass Grass Grass GrassSpacing from supporting structure— — —Free-standingFree-standingFree-standing1.3 m 0.4 m 1.3 m 1.3 mObstructions on roof— — — — — — None None None NoneObstacledistance— — — 25 m 25 m 25 m 19 m 19 m 19 m 19 mProbe material — — — — — — Teflon Teflon Teflon TeflonResidence time — — — — — — 3.8 s 10.1 s 2.1 s 5.7 s38

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. Azu re Way UTM X-Coordinate: 658246.700; UTM Y-Coordinate: 401 5402.000 Operative Schedule: 24 hours Sampling Methods: O 3 : Ultraviolet Absorption, API 400A PM 10 : Beta Attenuation, Thermo Electron FH62C14 NO 2 : Gas Phase Chemiluminescence, API 200E Predominant Wind Direction: Northwest Photograph Direction: North

PM 10 O 3 NO 2 Spatial scale Neighborhood Neighborhood Neighborhoo d Monitoring objective Population exposure Highest co ncentration 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 None39 PM 10 O 3 NO 2 Probe material — Teflon Teflon
Residence time — 2.1 s 2.1 s40

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: 401 0319.000 Operative Schedule: 24 hours Sampling Methods: O 3 : Ultraviolet Absorption, API 400 PM 10 : Beta Attenuation, Thermo Electron FH62C14 Predominant Wind Direction: Northwest Photograph Direction: West

PM 10 O 3 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 m41 PM 10 O 3 Probe material — Teflon
Residence time — 10.7 s42

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 M ill Rd. UTM X-Coordinate: 762202.400; UTM Y-Coordinate: 407 7598.000 Operative Schedule: 24 hours Sampling Methods: O 3 : Ultraviolet Absorption, API 400A PM 10 : Beta Attenuation, Thermo Electron FH62C14 Predominant Wind Direction: Southwest Photograph Direction: West

PM 10 O 3 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 None43 PM 10 O 3 Probe material — Teflon
Residence time — 10.3 s44

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 Pkw y., E. Flamingo Rd. UTM X-Coordinate: 667832.143; UTM Y-Coordinate: 399 8918.690 Operative Schedule: 24 hours Sampling Methods: CO: Gas Filter Correlation CO Ana lyzer, API 300E O 3 : Ultraviolet Absorption, API 400E PM 10 : Beta Attenuation, Thermo Electron FH62C14 Predominant Wind Direction: Southwest Photograph Direction: Northwest

PM 10 CO O 3 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 PM 10 CO O 3 Obstacle distance No obstacles — —
Probe material — — Teflon
Residence time — — 3.5 s46

Figure 14 – Palo Verde

Type: SLAMS Palo Verde (PV) (32-003-0073) Location: 333 Pavilion Center Dr., Las Vegas, NV 89 144 Three Closest Roads: W. Alta Dr., S. Town Center Dr ., W. Charleston Blvd. UTM X-Coordinate: 649914.700; UTM Y-Coordinate: 400 4542.000 Operative Schedule: 24 hours Sampling Methods: O 3 : Ultraviolet Absorption, API 400E PM 10 : Beta Attenuation, Thermo Electron FH62C14 Predominant Wind Direction: Southwest Photograph Direction: East

PM 10 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 PM 10 O3
Probe material — Teflon
Residence time — 2.1 s48

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: 399 7162.000 Operative Schedule: 24 hours Sampling Methods: O 3 : Ultraviolet Absorption, API 400A PM 10 : Beta Attenuation, Thermo Electron FH62C14 Predominant Wind Direction: South Photograph Direction: Southwest

PM 10 O 3 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 s49

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: 400 3698.329 Operative Schedule: 24 hours Sampling Methods: CO: Gas Filter Correlation, API 3 00E PM 10 : Beta Attenuation, Thermo Andersen FH62C14 PM 2.5 : Beta Attenuation, Thermo Electron FH62C14 PM 2.5 : Andersen RAAS2.5-300 FRM PM 2.5 : Collocated: Andersen RAAS2.5-300 FRM Predominant Wind Direction: South Photograph Direction: Northeast

PM 10 CO PM 2.5 (FRM) PM 2.5 FRM Collocated PM 2.5

Continuous Spatial scale Neighborhood Neighborhood Neighborhoo d 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

PM 10 CO PM 2.5 (FRM) PM 2.5 FRM Collocated PM 2.5

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. C imarron Rd. UTM X-Coordinate: 656223.000; UTM Y-Coordinate: 400 4175.000 Operative Schedule: 24 hours Sampling Method: O 3 : Ultraviolet Absorption, API 400 Predominant Wind Direction: Southwest Photograph Direction: West

O 3 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 s52

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 Blv d., S. Nellis Blvd. UTM X-Coordinate: 674872.900; UTM Y-Coordinate: 400 1556.000 Operative Schedule: 24 hours Sampling Methods: O 3 : Ultraviolet Absorption, API 400A CO: Gas Filter Correlation Analyzer, API 300E Predominant Wind Direction: Southeast Photograph Direction: North

CO O 3 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 s53

Figure 19 – Sunrise Hospital

Type: Transmissometer (Visibility Monitoring Networ k)

Sunrise Hospital—T1 transmitter Location: 3186 S. Maryland Pkwy., Las Vegas, NV 891 09 Three closest roads: E. Desert Inn Rd., Vegas Valle y 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-254

Figure 20 – North Las Vegas Airport

Type: Visibility Camera (Visibility Monitoring Netw ork) North Las Vegas Airport Location: 2730 Airport Drive, North Las Vegas, NV 8 9032 Three closest roads: Cheyenne Ave., North Decatur B lvd., North Rancho Drive Equipment: High-Resolution Digital Camera System, O lympus E-420 Series55



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

Figure 21 – CO Monitors56

Figure 22 – O 3 Monitors

Note: Red dots indicate 2010 summer O 3 study sites.57

Figure 23 – NO x Monitors58

Figure 24 – Continuous PM 10 Monitors59

Figure 25 – Continuous PM 2.5 Monitors60

Figure 26 – Filter-Based PM 2.5 Monitors61



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

On November 12, 2008, EPA released the revised NAAQ S for Pb. Revisions to the Pb ambient air monitoring rule was finalized on January 26, 20 11 [75 FR 81126 (December 27, 2010)]. As a result of these changes, Clark County must now addr ess two Pb monitoring requirements: ambient nonsource-oriented monitoring and ambient sou rce-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 nationa lly contracted Research Triangle Institute laboratory for sample analysis. The source emission t hreshold for the ambient source-oriented monitoring requirement is 0.50 tons per year, and D AQEM is identifying potential sources that may trigger that requirement. A preliminary assessm ent shows no such sources within Clark County, but an official emissions inventory is bein g 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 SO 2 : 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 SO 2 monitors must be operational by January 1, 2013. I n addition to 1- hour averages, DAQEM will also report maximum 5-min ute block averages in accordance with the revised SO 2 rule. Historically, SO 2 data in Clark County is well below the NAAQS; ther efore, DAQEM will operate one SO 2 monitor at the NCore site.

On January 22, 2010 [75 FR 6474 (February 9, 2010)] EPA revised the primary NAAQS for NO 2 . EPA established requirements for an NO 2 monitoring network with monitors sited at locations where maximum NO 2 concentrations are expected to occur, including wi thin 50 m of major roadways, and monitors sited to measure the area-wi de NO 2 concentrations that occur more broadly across communities. DAQEM is currently inve stigating siting locations and believes that the City Center site (32-003-0016) will meet this r equirement. City Center is one of the valley’s ten highest traffic count areas. Its diverse traffi c mix includes older vehicles and it experiences significant congestion at least twice per day. It i s 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 ma y also be suitable for microscale monitoring; a previous study determined that O 3 was undergoing titration by NO x from vehicles on U.S. 95. In addition, City Center has the flexibility to qualify for neighborhood scale monitoring. New roadside NO 2 monitors must begin operating no later than January 1, 2013.

On January 28, 2011, EPA proposed retaining the exi sting 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 monitori ng with the near-road NO 2 monitor.

40 CFR § 58.10(3) requires that NCore stations be o perational by January 1, 2011, and DAQEM is operating a new NCore monitoring station at Jero me 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 continuousl y year-round except PM 2.5 FRM samplers, speciation samplers, and monitors for seasonal stud ies. O 3 monitoring at Mesquite and Apex may also be conducted in conjunction with summer O 3 studies.63



### 14. Summary of Monitoring Requirements

40 CFR § 58 dictates the maintenance requirements f or 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 O 3 concentration is the Joe Neal station at 6651 W. A zure Way, Las Vegas, NV.

• The area of highest PM 10 concentration is the Apex station (now closed) at 12101 U.S. Highway 93, Las Vegas, NV. Second highest is t he Joe Neal station at 6651 W. Azure Way, Las Vegas, NV.

• The area of highest annual average PM 2.5 concentration is the Sunrise Acres station.

• The area of highest annual average NO 2 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 O 3 concentration is 0.053 ppm.

- Annual average PM 10 concentration is 24.93 μ g/m 3

.

- Average PM 2.5 concentration is 7.42 μ g/m 3

.

- Annual average NO 2 concentration is 0.013 ppm.

• City of Henderson:

- Annual average PM 10 concentration is 14.8 μ g/m 3

.

- Average PM 2.5 concentration is 5.56 μ g/m 3

.

• City of Boulder City:

- Annual average O 3 concentration is 0.052 ppm.

- Annual average PM 10 concentration is 12.6 μ g/m 3

.
• City of Mesquite:

- Annual average O 3 concentration is 0.049 ppm.

- Annual average PM 10 concentration is 13.3 μ g/m 3

.

3. Determine the impact significant sources have on ai r quality.

• CO sources: vehicle and non-vehicle combustion sour ces.

- Impact: zero exceedance days.

• NO 2 sources: vehicle and non-vehicle combustion source s.

- Impact: zero exceedance days.

• PM 2.5 sources: vehicle and non-vehicle combustion source s, fugitive dust.

- Impact: one exceedance day because of fireworks.

• PM 10 sources: fugitive dust, industrial processes.

- Impact: zero exceedance days. 4. Determine general background concentration levels.64

• Jean:

- PM 10 : 2010 average = 8.7 μ g/m 3

.

- PM 2.5 : 2010 average = 3.45 μ g/m 3

.

- O 3 : 2010 average = 0.053 ppm.

5. Determine the extent of regional pollutant transpor t among population areas.

• Studies show that O 3 transport and regional contributors have an influe nce on Clark County, which may result in O 3 exceedances. Smoke from seasonal wildfires may contribute significantly to O 3 and PM levels in Clark County.

6. Determine health and welfare related impacts in rur al and remote areas.

• Monitoring at Jean serves a rural area, provides ba ckground levels, and can be used to indicate transport from California.

• Monitoring at Boulder City serves a rural populatio n.

• Monitoring at Mesquite serves a rural population an d 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 20 10 CO 0 5 O 3 2 13 year around operations5 summer study (including 1 chemiluminescent) SO 2 0 0 NO 2 0 2 PM 10 BAM 4-8 13 PM 2.5 BAM 0 6 PM 2.5 FRM 2 + collocation 4 + collocation

DAQEM uses the following criteria to evaluate the p lacement 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 pla ns require no additional instrumentation.65



### 15. Quality Assurance Program

DAQEM conducted performance field evaluations throu ghout 2010. These audits indicated that DAQEM is providing instrument data of sufficient qu ality to satisfy EPA guidance parameters and meet Measurement Quality Objectives.

All gaseous criteria pollutant monitoring instrumen ts were field-audited, including two NO 2 instruments, five CO instruments, and thirteen O 3 instruments. The only failure of DAQEM Measurement Quality Objectives took place at the Bould er City site on June 22, 2010, caused by a calibrator flaw; the instrument was promptly recali brated, and a follow-up audit on August 13 was satisfactory. Five O 3 sites, including Apex, Craig Road, Lone Mountain, Mesquite, and Orr Middle School, were shut down, but may be used agai n for special studies. DAQEM has no SO 2 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 m oved to Jerome Mack Middle School. Thirteen continuous PM 10 C-14 BAMs and six continuous PM 2.5 C-14 BAMs underwent performance evaluations for flow, temperature, pressure, and time. Five PM 10 μ 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 PM 2.5 μ sites—Apex and Craig Road.

Each continuous PM 2.5 BAM is equipped with a VSCC as a second stage sepa rator. PM 2.5 FRM samplers are equipped with a mix of VSCC separators and Well Impactor Ninety-Six impactors. Each operational PM 2.5 FRM was audited quarterly in 2010 for a total of f ifteen evaluations of the three sites (including Sunrise Acres, which hos ts the precision pair). In the final quarter of 2010, the FRM at J.D. Smith was moved to Jerome Mac k. All continuous particulate monitors were evaluated semiannually.

Evaluations were balanced throughout the calendar y ear. Any scheduling adjustments favored pollutant seasonality, e.g., more CO instruments we re audited during the winter months and more O 3 instruments during the summer months. Audit evalua tions of the gaseous pollutants used the transmutation values of slope/intercept cr eated by calibration activity from the IPS MeteoStar Leading Environment Analysis and Display Sy stem (LEADS), DAQEM’s data acquisition system. Assessments of data flow—from collecti on, to storage, to transfer, to processing with verification, to validation, to review and sub mittal—indicated consistent, thorough, and acceptable handling regimens. Precise and accurate da ta 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 fo r internal QA performance evaluations.

Date Pollutant Monitoring Stations
3/10/2010 PM 10 Jean, Green Valley, Paul Meyer
3/11/2010 PM 10 Lone Mountain, Palo Verde 3/12/2010 PM 10 Mesquite 4/22/2010 PM 10 Orr66 Date Pollutant Monitoring Stations
6/8/2010 PM 10 Craig Road, J.D. Smith, Joe Neal, Sunrise Acres 6/22/2010 PM 10 Boulder City
9/1/2010 PM 10 Green Valley, Jean
9/10/2010 PM 10 Paul Meyer

9/29/2010 PM 10 Palo Verde
10/25/2010 PM 10 Boulder City

10/27/2010 PM 10 Joe Neal

11/8/2010 PM 10 Sunrise Acres
11/29/2010 PM 10 J.D. Smith
3/10/2010 PM 2.5 continuous Green Valley, Jean
3/12/2010 PM 2.5 continuous Apex

6/8/2010 PM 2.5 continuous Craig Road, J.D. Smith, Jean

9/1/2010 PM 2.5 continuous Green Valley, Jean
9/10/2010 PM 2.5 continuous Apex

9/16/2010 PM 2.5 continuous Craig Road

11/8/2010 PM 2.5 continuous Sunrise Acres
11/9/2010 PM 2.5 continuous J.D. Smith

3/26/2010 PM 2.5 filter-based Jean, Sunrise Acres, J.D. Smith

5/19/2010 PM 2.5 filter-based J.D. Smith, Sunrise Acres
5/27/2010 PM 2.5 filter-based Jean

9/9/2010 PM 2.5 filter-based Jean, J.D. Smith, Sunrise Acres

10/16/2010 PM 2.5 filter-based Sunrise Acres
10/25/2010 PM 2.5 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 O 3 Jean, Paul Meyer

3/11/2010 O 3 Lone Mountain, Palo Verde, Walter Johnson
3/12/2010 O 3 Apex

4/22/2010 O 3 Orr

6/10/2010 O 3 J.D. Smith
6/22/2010 O 3 Boulder City

8/13/2010 O 3 Boulder City

9/15/2010 O 3 Craig Road
9/22/2010 O 3 Mesquite

10/27/2010 O 3 Joe Neal

12/6/2010 O 3 Winterwood

3/30/2010 NO 2 Joe Neal67 Date Pollutant Monitoring Stations
6/9/2010 NO 2 J.D. Smith

Speciation sampling is grant-funded, and DAQEM oper ates 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 sampl ing equipment anywhere in the county to support special project initiatives. Initial sam pling 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 Nation al Performance Audit Program (NPAP). This Through-the-Probe (TTP) performance evaluation , which focuses on gaseous criteria pollutants, is contracted and scheduled by Region 9. Aud it results are immediately available. DAQEM received a “Pass” audit report for all TTP performa nce evaluations in 2010.

The following table shows the 2010 TTP event schedu le.

Monitoring Station Pollutant TTP Conducted
Walter Johnson O 3 4/12/2010 Sunrise Acres, J.D. Smith CO, O 3 4/13/2010 J.D. Smith, Joe Neal O 3 , NO 2 4/14/2010

Each year, the PM 2.5 FRM sampling network undergoes a Performance Evalu ation Program (PEP) audit. Through EPA Region 9, an independent a uditor is contracted to perform external field audits quarterly. The contractor submits eval uation results to the AQS database. Because of the manual methods used to audit FRM samplers, audi t results (in μ g/m 3 ) are generated at some point after the audit. The point at which audit res ults are available varies.

The following table summarizes 2010 PEP audit event activity.

PM 2.5 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 11/10/201069



### 17. Network Modifications Completed in 2010

The following table summarizes network changes made in 2010.

Action Date Reason Apex station closed.

PM 10 C-14, PM 2.5 C-14, and O 3 sampling terminated, though O 3 and meteorological monitoring may occur during ozone season. September 2010 Budget and manpower constraints.

E. Craig Road station closed.

PM 10 , PM 2.5, and O 3 sampling terminated.

Speciation sampling moved to NCore site (Jerome Mack). September 2010 Land lease issue, budget and manpower constraints.

PM 2.5 FRM sampler at J.D. Smith moved to NCore site (Jerome Mack). September 2010 PM 2.5 FRM required at NCore.
Jerome Mack site construction completed.

Speciation samplers started operation.

PM 2.5 FRM sampler started operation. May 2010

May 2010

October 2010 NCore site became operational for limited

sampling.

Lone Mountain site closed.

O 3 and PM 10 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.

PM 10 C-14 and O 3 monitoring terminated, though O 3 monitoring may occur during

ozone season. September 2010 Land lease issue; budget and manpower constraints.

Orr site closed.

PM 10 C-14, O 3 , and CO monitoring terminated. April 2010 Budget and manpower constraints.70



### 18. Network Modifications Proposed

This section describes anticipated and potential ch anges to the air monitoring network over the next two years. The actions proposed constitute Cla rk County’s official approval request to EPA Region 9.

Financial, technical, staffing, and regulatory chal lenges 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 ter minate sites or equipment beyond what is specified in this plan. The following table lists p roposed site and/or equipment terminations over the next two years.

Site/Equipment Termination Date Explanation

PM 2.5 FRM at Jean site. To be determined Anticipate continuous PM 2.5 FEM deployment; Sunrise Acres has primary and collocated PM 2.5 FRM for the network. CO monitoring at J.D. Smith, Orr, and Winterwood sites. To be determined No EPA requirement for CO monitori ng.

O 3 monitoring at Winterwood and Boulder City sites. To be determined EPA requires only two sites for O 3 monitoring.
Apex and Jean sites. To be determined Unresolved le ase issues. Additional site closures. To be determined Sites cl osed because of resource limitations. Note: ARM = Approved Regional Method.

Termination Considerations

PM 2.5 FRM sampler at Jean site. In 2010, DAQEM maintained operations in the PM 2.5 FRM filter-based network at a level that matched grant fun ding. If this network is reduced, DAQEM will continue to keep using, and applying for, grant fun ding based on activities outside the PM 2.5 FRM network, including the PM 2.5 gravimetric laboratory, PM 2.5 BAM operations, PM 2.5 speciation sampling, PM 2.5 FEM deployment, applicable NCore monitoring, and r elated training. The criteria in 40 CFR § 58.14(c)(3) may justify discon tinuing filter-based PM 2.5 FRM samplers altogether; in the future, DAQEM goals include replacin g current non-designated PM 2.5 BAMs with FEM-designated BAMs. Sunrise Acres has the primary and collocated PM 2.5 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 si tes. 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 t erminate CO monitoring at these sites to redirect program resources. DAQEM anticipates conductin g near-road CO monitoring based on the newly proposed CO rule.

O 3 monitoring at Winterwood and Boulder City sites. 40 CFR § 58 requires operating two O 3 monitoring sites. DAQEM will evaluate the O 3 data from these sites, along with SIP requirements, and may terminate O 3 monitoring at these sites to redirect program reso urces. Winterwood measures lower O 3 readings in the Las Vegas Valley, and Boulder City may not be71

sufficiently representative. DAQEM will continue to monitor and evaluate O 3 in the urban core, high-concentration areas, background areas, and oth er 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 requir e terminating all monitoring operations.

Additional Site Closures. Reductions in budget and staff or equipment failure s may require DAQEM to consider further site closures in 2011.

Proposed Installations and Considerations

Apex. DAQEM plans to install a sonic detection and rangi ng 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 eval uating pollution transport issues.

Other Considerations

Ivanpah Valley. DAQEM is conducting background monitoring at the J ean site in the Ivanpah Valley. Since there may be construction in this are a over the next few years, the Jean site may continue to monitor PM 10 , PM 2.5 , other criteria pollutants, and meteorological par ameters.

Spatial gaps and potential high pollutant sites. DAQEM has an interest in filling spatial monitoring gaps and monitoring high-concentration areas. T hrough special studies, modeling, and forecasting, DAQEM has projected spatial gaps and eleva ted pollutant concentrations in specific areas throughout the county: Indian Springs, Laughl in, 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 informati on and data with other entities that monitor air quality, including the La s Vegas Paiute Tribe. DAQEM may also seek to enhance current data sets through data exchanges, a nd 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 PM 10 and O 3 throughout Clark County. The system could move bet ween various locations to assess air quality and help determine where to site p ermanent 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, DA QEM will evaluate other network changes based on results from the following studies:

1. Network Assessment (submitted June 30, 2010) 2. PM

10 Saturation Study (December 2005). 3. Clark County Regional Ozone & Precursor Study (March 2006).72

4. “Field Measurements and Documentation of Wildfire E vent Air Quality Impacts during the 2009 and 2010 Summer Wildfire Season” (February 2011). 5. Analysis to determine the O 3 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 r eevaluating the CO network and considering site closures.) 7. The EPA designation of the Thermo Electron FH62C14 PM 2.5 BAM as an FEM and the potential for using the MetOne 1020 BAM as a design ated PM 2.5 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 cl osure of a particular monitoring station or site. This plan constitutes Clark County’s official reque st to EPA Region 9 to discontinue monitoring under these or similar circumstances.

Site Agreements

Site Documentation Owner Terms Boulder City: 1 air quality monitoringstation, 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 StationarySource; 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 Unders tanding; NDOT = Nevada Department of Transportation; ROW = right-of-way. *Agreements for these sites are under review; howev er, 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 o bjective information in the AQS database.

Site Monitor Measurement Scale Monitor Objective Ty pe Apex O 3 Regional scale Regional transport Apex PM 10 C-14 Regional scale Source-oriented Apex PM 2.5 C-14 Regional scale Source-oriented Boulder City O 3 Neighborhood Population exposure Boulder City PM 10 C-14 Neighborhood Population exposure E. Craig Road O 3 Neighborhood Population exposure E. Craig Road PM 10 C-14 Neighborhood Highest concentration E. Craig Road PM 2.5 C-14 Neighborhood Population exposure E. Sahara CO Neighborhood Population exposure Green Valley PM 10 C-14 Middle scale Population exposure Green Valley PM 2.5 C-14 Middle scale Population exposure J.D. Smith CO Neighborhood Population exposure
J.D. Smith NO x Neighborhood Highest concentration
J.D. Smith NO 2 Neighborhood Highest concentration
J.D. Smith O 3 Neighborhood Population exposure
J.D. Smith PM 10 C-14 Neighborhood Population exposure
J.D. Smith PM 2.5 FRM Neighborhood Population exposure
J.D. Smith PM 2.5 C-14 Neighborhood Population exposure
Jean O 3 Regional scale Regional transport
Jean PM 10 C-14 Regional scale General/background

Jean PM 2.5 FRM Regional scale General/background

Jean PM 2.5 C-14 Regional scale General/background

Jerome Mack PM 2.5 FRM Neighborhood Population exposure
Joe Neal NO x Neighborhood Population exposure
Joe Neal NO 2 Neighborhood Population exposure
Joe Neal O 3 Neighborhood Highest concentration
Joe Neal PM 10 C-14 Neighborhood Population exposure
Lone Mountain O 3 Neighborhood Population exposure
Lone Mountain PM 10 C-14 Neighborhood Population exposure Mesquite O 3 Neighborhood Population exposure Mesquite PM 10 C-14 Middle scale Population exposure Orr CO Neighborhood Population exposure
Orr O 3 Neighborhood Population exposure
Orr PM 10 C-14 Neighborhood Population exposure
Palo Verde O 3 Neighborhood Population exposure
Palo Verde PM 10 C-14 Neighborhood Population exposure75 Site Monitor Measurement Scale Monitor Objective Ty pe Paul Meyer O 3 Neighborhood Population exposure Paul Meyer PM 10 C-14 Neighborhood Population exposure Sunrise Acres CO Neighborhood Highest concentration
Sunrise Acres PM 10 C-14 Neighborhood Population exposure
Sunrise Acres PM 2.5 FRM Neighborhood Highest concentration
Sunrise Acres PM 2.5 FRM Neighborhood Highest concentration
Sunrise Acres PM 2.5 C-14 Neighborhood Highest concentration
Walter Johnson O 3 Neighborhood Population exposure Winterwood CO Neighborhood Population exposure
Winterwood O 3 Neighborhood Population exposure76



### 21. Receptor-Measured Criteria Pollutant Trends

The following pages contain plots of criteria pollu tant 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 2010High 8-Hour AverageConcentration (ppm)

Year

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



### EPA 8

- Hour77

Figure 28 – O 3 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 200 7 2008 2009 2010Ozone (PPM) DAQEM Ozone Fourth High Eight Hour Average

SE

CC

CR

FL

AP

MQ

PM

WJ

LO

PVFigure 29 – SO 2 Trends

0 20 40 60 80

1998 1999 2000SO2 One Hour HighConcentration (ppb) EPA 1 Hour Standard 75 ppb

78 2001 2002 2003 2004 2005 2006 2007 2008 E. Sahara79

Figure 30 – NO 2 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 2010Annual Mean (ppb)

Year Apex J.D. Smith Jean E. Sahara Palo Verde Joe Neal EPA Annual Standard80

Figure 31 – Continuous PM 10 Trends

0 10 20 30 40 50 60 70 80 90 100

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010Annual Mean (μg/M3) 

### PM 10

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 Mesquite81

Figure 32 – Filter-Based PM 2.5 FRM Trends

0 5 10 15 20 25

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010Annual Mean (μg/M3)

Year

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

EPA Annual82

Figure 33 – Continuous PM 2.5 Annual Mean Trends

0 5 10 15 20 25

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010Annual Mean (μg/M3)

Year Craig Road Green Valley J. D. Smith Sunrise Acres Apex Jean83

Figure 34 – Continuous vs. Filter-Based PM 2.5 Trends

0 2 4 6 8 10 12 14 16 18 20

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010Annual Mean (μg/M3)

Year

J.D. Smith FRM J.D. Smith BAM Sunrise Acres FRM Sunrise Acres BAM Jean FRM

Jean BAM84



### 22. Pollen Network

The pollen network, which was separate from the NAA QS 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 Cou nty are the fruitless mulberry, which pollinates in March, and the European olive, which polli nates in April. Clark County banned further planting of these trees (except certified low-polli nating varieties) because of their high levels of pollen (see Section 44 of the Clark County Air Qual ity Regulations).

DAQEM operated nine pollen monitoring stations in C lark County during 2010, using the Multidata Model 40 rotorod sampler at each site. The pol len 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 n etwork in 2010.

The pollen monitoring network was dynamic, and moni toring locations changed depending on valley growth, pollen levels, and public requests. However, Clark County terminated pollen monitoring in October 2010 due to resource constrai nts and reduced staffing levels.85

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