4-25 

4.4.2 Public Workshops 

Beginning in September 1999, CCDCP and AQD staff 

jointly conducted a series of workshops to develop new 

fugitive dust controls for disturbed open areas and 

vacant lots. Initially, these regulations were developed 

as amendments to the existing Section 41 Air Quality 

Regulations. As draft regulations were developed for 

other fugitive dust sources, they were also incorporated 

into Section 41. As a result of public comments made 

during the workshop process, regulations for the control 

of disturbed open areas and weed abatement; unpaved 

roads; unpaved parking lots; and construction activities 

were separated into individual sections of the Air Quality 

Regulations in May of 2000. The draft regulations for 

disturbed open areas were rewritten as a new Section 

90. Draft regulations for unpaved roads were rewritten 

as Section 91. Draft regulations for unpaved parking 

lots were rewritten as Section 92. Draft regulations for 

street sweeping equipment, paved road shoulders, and 

paved medians were developed as Section 93. Draft 

regulations for enhanced requirements for construction 

activities became Section 94. A total of 20 workshops 

were conducted between September 1999 and 

November 2000 on these draft regulations. 

Documentation for the workshops is in Appendix F. 

These workshops were advertised and opened to the 

public in compliance with NRS 241 Open Meeting Law 

requirements. 

In the following sections (4.4.2.1 through 4.4.2.5) a 

summary of the significant issues brought up at the 

workshops is provided for each of the major 

topics/significant emission sources that were addressed. 

A chart is provided for each significant source category 

that lists the potential BACM from Section 4.3 and 

indicates the decision resulting from the evaluation of 

each measure to either develop/strengthen appropriate 

control measures or to discount the measure from 

further consideration. A discussion of the implemented 

control measures is then provided in Section 4.5.

4.4.2.1 Emission Inventory Issues

During these workshops, concern was expressed 

regarding the draft emission inventories prepared by the 

CCDCP. Almost all participants believed that the 

Workshops Held on 

Fugitive Dust Controls

Emission Inventories 

Discussed
 4-26 

emissions from paved roads were greatly 

overestimated. The CCDCP staff explained the U. S. 

EPA approved AP-42 emission algorithm for paved road 

dust, noted that research on paved road dust emissions 

was ongoing, and committed to updating the inventories 

when better emission estimates were available. There 

was some disagreement among stakeholders over the 

contribution of unpaved road dust to the inventories. 

Many felt that this source category might be 

underestimated in the inventory. Some members of the 

public also indicated that they thought the estimates of 

emissions from disturbed open areas were 

overestimated. There was much discussion on the 

contribution of construction activities, including the 

contribution of silt loadings on paved roads from 

construction activities. CCDCP explained how the 

emission inventory estimates were developed and has 

refined the draft emission inventories. The inventories 

are discussed in Chapter 3 and Appendix B of this SIP. 

4.4.2.2 Disturbed Open Area/Vacant Lot/Unpaved 

Parking Lot Issues 

Listed below in Table 4-10 are the BACM implemented 

for emissions from disturbed vacant land and unpaved 

parking lots identified as a result of the research 

performed as described above. For a detailed 

description of the implemented control measures, see 

Sections 4.5.2.1, 4.5.2.2, 4.5.3.1 and 4.5.3.2. 

Emission Inventory 

Development 

Discussed in 

Appendix B 

Table 4-10 

BACM for Disturbed Vacant Land and Unpaved Parking Lots 

Control Measure Implemented 

Limit off-road use of RVs on open land Yes 

Vacant land stabilization Yes 

Construct windbreaks Optional 

Controls on weed abatement Yes 

Prohibit unpaved parking lots Proposed 

Stabilize surface of unpaved parking lots Yes 

Dust abatement and management plans for 

large tracts of governmentally owned lands Partial – See discussion below 
 4-27 

Major issues related to the potential control measures 

for disturbed open areas and vacant lots included 1) the 

cost to property owners of complying with the proposed 

requirements, and 2) the liability of property owners to 

pay the cost of remediating unauthorized dumping and 

ATV use on their property. Another concern was that 

local regulations sometimes make it difficult or 

impossible to get local approval to fence a parcel. 

Some participants expressed the opinion that it was 

acceptable to require stabilization and prevent vehicular 

use on urban vacant lots, but that the regulations should 

not apply to “open areas.” They expressed the view that 

the County should not adopt regulations that would 

result in “fencing off the desert.” 

The use of windbreaks was addressed and they were 

determined to be suitable as an optional control 

measure. This option was made subject to approval 

since requirements that were developed and included in 

AQR Section 90 to prevent motor vehicle trespass and 

to stabilize disturbed surfaces are more stringent than a 

stand alone requirement to construct windbreaks. The 

placement of windbreaks in terms of both orientation 

and spacing is critical if windbreaks are to be effective in 

controlling dust. Where surfaces have been stabilized, 

windbreaks are not necessary. Therefore, AQR Section 

90 does not require that windbreaks be constructed, but 

leaves this control as an option if approved by the AQD 

Control Officer and U. S. EPA. Approval is subject to a 

determination that use of windbreaks as proposed will 

provide a level of control equivalent to other BACM 

approved for open areas and disturbed vacant land. 

Site-specific dust mitigation plans for large parcels were 

discussed by CCDCP and AQD staff. As discussed in 

Section 4.3.1, requiring dust mitigation plans for 

individual parcels was not found to be cost effective. 

However, stabilization plans from large property owners 

with several parcels would be an effective method for 

enforcing vacant land regulations. This would be 

especially effective if the parcels had a high potential of 

being disturbed. As described in Section 4.8.3.3, Clark 

County is proposing an amendment to AQR Section 

90.2.1.3 to require property owners managing over 

10,000 acres to prepare dust mitigation plans by 

January 1, 2002. It was decided that requiring plans 

Disturbed Open Areas 

Issues Discussed 

 
 4-28 

would be an enforcement burden, but that large property 

owners, including governmental entities, would be 

contacted individually and plans developed for their 

parcels. 

The proposed U. S. EPA test methods for soil surface 

stability, which were used in the Maricopa County 

Federal Implementation Plan (FIP), were extensively 

criticized. AQD enforcement staff suggested thatthese 

tests were too labor intensive to allow for cost-effective 

enforcement of the regulation. Members of the public 

said the tests were too complicated for the average 

property owner to be able 

to use in determining if his/her property was in 

compliance with the regulation. At the end of these 

discussions, a general consensus evolved that resulted 

in the adoption of Section 90 of the Air Quality 

Regulations. 

Some of the comments made concerning the 

requirements for disturbed open areas were also made 

concerning the proposals to regulate vacant lots. These 

included comments on cost, test methods, and fencing. 

Use of unpaved areas for intermittent parking was also 

discussed at length. At the end of these discussions, a 

general consensus evolved that resulted in the adoption 

of Section 92 of the Air Quality Regulations, requiring 

vacant lots and disturbed open areas to be stabilized 

and off-road vehicle use prohibited. 

Current zoning regulations and development standards 

for Clark County and the cities of Las Vegas, North Las 

Vegas, and Henderson generally require paved parking 

for new development. Consideration was therefore 

given to prohibiting construction of any new unpaved 

parking lots. During consideration of this issue, it was 

noted that requiring paved parking lots for rural public 

facilities such as trailheads, campgrounds, etc., might 

conflict with the rural nature of these facilities and 

require more intensive construction in these rural areas. 

A consensus evolved to allow stabilization of unpaved 

parking lots in lieu of a mandatory paving requirement. 

For urban parking facilities that are used on a yearround basis, it is believed that paving will be the most 

cost-effective stabilization method. Clark County 

currently proposes to strengthen this requirement by 

 

Soil Surface Stability 

Tests Difficult To Use

 

Vacant Lots, Disturbed 

Open Areas To Be 

Stabilized; Off-Road 

Vehicle Use Prohibited
 4-29 

prohibiting construction of new unpaved parking lots 

except where a paved parking lot conflicts with rural 

facilities such as trailheads or campgrounds. 

4.4.2.3 Construction Activity Issues 

The BACM identified for control of dust from 

construction activities are listed in Table 4-11. A 

detailed description of the implemented control 

measures can be found in Sections 4.5.2.3 and 4.5.3.3. 

Table 4-11 

BACM for Construction Activities 

Control Measure Implemented 

Strengthen requirements of existing fugitive dust control rules Yes 

Provide for better enforcement of fugitive dust control rules Yes 

Mitigation bond requirement to insure implementation of dust 

control plan Yes 

Dust control plans for construction/land clearing and 

demolition Yes 

Dust control monitor required for construction sites having 

more than 50 acres of actively disturbed area Yes 

Track out control Yes 

Staging areas, equipment storage, and material storage 

areas 

Yes 

Use of surfactants or tackifiers Yes 

High-wind operating restrictions Yes 

Phasing land development Yes -- Partial 

Stabilized disturbed inactive surfaces Yes 

Dust controls for blasting of soil and rock Yes 

Dust controls for abrasive blasting Yes 

Dust controls for crushing Yes 

Dust controls for landscaping Yes 

Dust controls for paving/subgrade preparation Yes 

Dust controls for screening Yes 

Dust controls for construction traffic Yes 

Dust controls for trenching Yes 

Dust controls for truck loading Yes 

Dust controls for stockpiles Yes 

Require visible emission limits not to exceed 20% opacity Yes 

Limit visible emissions to 100 feet Yes 

Prevent visible emissions from crossing property line Proposed 
 4-30 

For several construction activities, Clark County did not 

find specific control measures adopted in other areas 

through the potential BACM research. New control 

measures were developed by Clark County as potential 

BACM to reduce emissions from these construction 

activities. 

Extensive discussion was held on developing new and 

enhanced control measures for construction activities. 

Stakeholders noted that our minimum fines are the 

highest in the nation for fugitive dust violations, but that 

we still are violating the federal air quality standards. It 

was asserted that the “command and control” approach 

had not proven effective here. Examples were cited 

where permit conditions under the current rule did not 

allow the most efficient or cost-effective control measure 

to be employed. The need to be able to apply the most 

appropriate Best Management Practice for the job was 

emphasized. A suggestion was made to issue only one 

dust control permit for each project and make the 

applicant responsible for dust control on the project. 

Concerns were expressed regarding the U. S. EPA 

opacity test. Some participants expressed doubt that it 

would be possible to comply with this standard when 

working in difficult soils. CCDCP staff noted that U. S. 

EPA required a quantitative, verifiable, and repeatable 

test method that could be related to the reduced 

emissions that would occur from the effective 

application of control measures. There was agreement 

to continue development of better test methods beyond 

submittal of the SIP. 

The Particulate Matter Control Research Advisory 

Committee (Advisory Committee) has funded a study of 

test methods that can be used to enforce the dust 

control standards for construction activities. U. S. EPA 

has provided additional funding for the study. The study 

began in early 2001, and it is expected the study will be 

finalized by August of the same year. The CCDCP has 

made a SIP commitment to initiate an additional study if 

the results of this study do not produce test methods 

that are acceptable. It is anticipated that the current 

study will result in acceptable test methods. The 

difficulty in developing acceptable test methods lies in 

the variety of activities that take place on construction 

Construction Activities 

Control Measures

Study Funded To 

Develop Test Methods 
 4-31 

sites and the different soil types present in the Las 

Vegas Valley. 

After extensive discussion, it was generally agreed that 

the new regulatory program should require site-specific 

and phase-specific dust control permits for larger 

projects and that the regulation incorporate an extensive 

list of BMP that would provide a comprehensive set of 

BACM to address fugitive dust from construction sites. 

BMP should generally be selected based on soil type as 

well as other factors specific to the construction site and 

activity. One suggestion put forward but not adopted 

was a limitation on the acreage that could be graded 

and disturbed at any one time. Opponents of this 

proposal suggested that in some instances, on very 

large projects, this requirement could force off-site 

hauling and stockpiling of fill dirt. This would not be 

necessary if there was not a limitation on the acreage 

that could be graded and kept disturbed at any one 

time. Staff reviewed dust control permits for large 

projects and determined that these issues were valid. It 

was also argued that the requirements for stabilizing 

any areas of a construction site that were disturbed 

would force developers to minimize disturbed areas to 

the maximum extent feasible for economic reasons. 

During the workshop process, it was noted that 

Maricopa County required dust control permits for all 

construction sites of one-tenth (0.1) acre or larger, 

whereas Clark County requires dust control permits for 

construction sites of one-quarter (0.25) acre or larger, 

trenching operations of 100 feet or greater, or demolition 

of structures of 1,000 square feet or greater. In some 

instances, the latter permit thresholds for dust producing 

activities may mandate permits on parcels of less than 

0.1 acre. Consideration was given to reducing the 

construction site size threshold to one-tenth (0.1) acre 

for requiring dust control permits. Most construction 

activities on these very small sites that do not include 

trenching or demolition are limited to remodeling. 

Small-scale remodeling does not typically involve 

significant dust producing activities. In addition, the 

Clark County regulation requires that BMP be employed 

for any dust producing activity that occurs, even when a 

permit is not required. It was therefore determined that 

reducing the construction site size threshold for 

Site-Specific Dust 

Mitigation Plans Part 

of BMP

Reducing 

Construction Site Size 

Threshold Provides No 

Air Quality Benefit
 4-32 

requiring dust control permits would provide no air 

quality benefits. 

Only one potential control measure for construction 

activities was rejected as infeasible for BACM during the 

rule development process. Prevention of visible 

emissions from crossing property lines was discussed at 

length during the rule development process. This 

performance standard was determined to be both 

infeasible and ineffective. For public works agencies 

and contractors working on road construction projects, 

this requirement may result in a no-visible-emissions 

standard due to the close proximity of a property line 

next to road rights-of-way. The same concern applies to 

any other work that occurs next to a property line. It 

would not be possible to comply with the required level 

of control that this performance standard would 

mandate under these circumstances. 

On the other hand, for construction work that occurs on 

a large section of land, this performance standard may 

allow almost unlimited emissions. Under these 

circumstances, this performance standard would 

provide no air quality benefits. This performance 

standard was therefore rejected as a BACM measure 

for construction activities. 

As a result of public comments received during the SIP 

development process, Clark County has reassessed this 

issue and determined that under some circumstances, 

this may be an appropriate performance standard. 

Therefore, Clark County is proposing to amend Section 

9.4 of the AQR to incorporate this requirement. 

At the end of these discussions, a general consensus 

evolved that resulted in the adoption of Section 94 of the 

Air Quality Regulations and the Section 94 Handbook of 

Best Management Practices by the Clark County Health 

District Board of Health. 

Visible Emissions 

Crossing Property 

Lines Deemed 

Infeasible, Ineffective

Section 94 Adopted
 4-33 

4.4.2.4 Paved Road Issues 

Table 4-12 identifies the potential BACM that were 

identified for control of paved road dust. For a detailed 

description of the implemented control measures, see 

Sections 4.5.2.4 and 4.5.3.4. 

Table 4-12 

BACM for Paved Road Dust 

Control Measure Implemented 

Preventing deposition of material onto paved roadways – 

stabilizing unpaved access points Yes 

Preventing deposition of material onto paved roads – 

construction track out Yes 

Preventing deposition of material onto paved roads – 

industrial site track out Yes 

Use of Pm10-efficient sweepers to clean paved roads Yes 

Use of vacuum crack seal equipment Yes 

Preventing deposition of material onto paved roads – 

stabilizing shoulders on paved roads Yes 

Preventing deposition of material onto paved roads – 

material transport controls –truck covers, freeboard 

requirement 

Yes 

Preventing deposition of material onto roads – storm water 

drainage Yes 

Cleanup of material spills and erosion-caused deposits Yes 

Routine sweeping/cleaning of paved roads Yes 

Some public works agencies initially expressed concern 

that the proposed draft regulations would require all new 

street sweeping equipment to be certified PM-efficient. 

This concern related to the need to retain some broomtype sweepers in the fleet. This issue was resolved 

when it was determined that the current list of Certified 

PM-Efficient Sweepers included broom sweepers. It 

was also suggested that the regulations allow the use of 

sweeping equipment that is “equivalent” to certified 

equipment. The issue of requiring new sweeping 

equipment for sweeping parking lots to be certified 

All Street Cleaning 

Equipment To Be 

Certified PM-Efficient 
 4-34 

PM-efficient was discussed at some length. At the end 

of these discussions, a general consensus evolved that 

resulted in the adoption of the sweeping requirements in 

Section 93 of the Air Quality Regulations, which require 

all street cleaning equipment to be certified. 

All of the public works departments have established 

programs for sweeping frequency in order to maximize 

the emission reduction benefits from their sweeper 

resources. These programs are described in Appendix 

J. 

The value of requiring paved road unpaved shoulders 

and medians to be stabilized and the time frame in 

which this should occur was discussed. Related to this 

discussion was the desire to preserve horse trails in the 

road rights-of-way in certain rural areas. Public works 

agencies indicated that surveying rights-of-way and 

establishing drainage where these improvements are 

required will take time and be expensive to resolve in 

some situations. The costs that could incur for the 

maintenance of limited access freeway rights-of-way 

and the difficulty of maintaining these areas were issues 

raised by the Nevada Department of Transportation 

(NDOT). At the end of these discussions, a general 

consensus evolved that resulted in the adoption of 

paved road unpaved shoulder and median stabilization 

requirements in Section 93 of the Air Quality 

Regulations, requiring unstable shoulders and medians 

to be stabilized within 365 days of discovery. Public 

works departments are developing plans for shoulder 

stabilization as described in Section 4.5.2.4.3. 

Control measures to control track out from 

stationary/industrial sources are addressed in Section 

4.6.1.1. Stationary sources are classified as an 

insignificant source category, but control measures to 

reduce track out onto paved roads are incorporated in 

the permit conditions for each source. 

Vacuum-type crack seal equipment evaluated by Public 

Works departments in the valley have been found to be 

of poor design and did not work well. Evaluation of offthe-shelf equipment available from manufacturers 

concluded that the current technology needs 

modification and/or improvement before the equipment 

Paved Road Unpaved 

Shoulder and Median 

Stabilization 

Requirements 

Adopted

Vacuum-Type Crack 

Seal Equipment Must 

Be Purchased in the 

Future 
 4-35 

Is as an effective means of reducing emissions in the 

crack sealing process. However, these modifications 

have been found to be relatively minor and Clark County 

is proposing to amend AQR Section 93 to require that 

future purchases of crack seal equipment employ this 

technology. 

4.4.2.5 Unpaved Road Issues

The BACM implemented for unpaved roads are listed in 

the controls shown in Table 4-13. A detailed description 

of these control measures is provided in Sections 

4.5.2.5 and 4.5.3.5. 

Table 4-13 

BACM for Unpaved Roads 

Control Measure Implemented 

Surface treatment to reduce dust from unpaved roads 

and alleys Yes 

Prohibition on new unpaved roads in public 

thoroughfares Yes 

Traffic reduction/speed control for unpaved roads Yes - For Construction 

Roads 

Potential control measures for unpaved roads were 

extensively discussed, with some participants 

suggesting that all unpaved roads should be paved and 

others suggesting that a much higher threshold for 

vehicle trips should be used for triggering a paving 

requirement. The time table for bringing unpaved roads 

into compliance was also discussed at length. 

After extended discussion spanning a number of 

workshops, a consensus was reached to require paving 

of all unpaved roads with vehicle traffic of 150 trips per 

day or greater over a three-year period, with one third of 

the roads paved each year. The only source from which 

the level of funding for paving roads can be acquired is 

through the Congestion Mitigation and Air Quality 

Improvement program (CMAQ). However, the total 

funding needed to ensure paving of these roads can 

only be accrued over a three-year period. The 

infeasibility of obtaining the funding necessary for this 

paving program in a shorter time period is a factor that 

Unpaved Roads 

Control Measures 

CMAQ Funding 

Commitment To Pave 

Unpaved Roads
 4-36 

prevents Clark County from demonstrating attainment of 

the 24-hour standard before 2006. 

Extended discussions took place on what constituted an 

unpaved road, who should be responsible in the case of 

easements, and who should be responsible for roads in 

public rights-of-way where a public agency has not 

accepted the road. A majority of participants indicated 

that they thought that the regulations should be drafted 

to allow the road-paving offset credits program to 

continue. At the end of these discussions, a general 

consensus evolved that resulted in the adoption of 

Section 91 of the Air Quality Regulations, requiring 

unpaved roads with greater than 150 ADT to be 

stabilized. 

Toward the end of these workshops, the issue of 

property owner and developer liability for potential 

environmental damage from the use of dust 

suppressant products emerged. As a result of these 

discussions, Clark County has committed to working 

with the State of Nevada to facilitate development and 

adoption of specifications for dust suppressant product 

use in Nevada. 

4.4.3 Public Hearings and Adoption

After public notice in compliance with NRS 241, a 

30-day public comment period was scheduled and 

public hearing set for March 23, 2000 on amendments 

to Section 41 for consideration by the Clark County 

Board of Health. This hearing was continued to the 

April 27, 2000 meeting of the Clark County Board of 

Health. After rewriting the draft regulations as 

amendments to Section 0 and adding Sections 90, 91, 

92, 93, and 94, a public hearing was scheduled for the 

May 25, 2000 meeting of the Clark County Board of 

Health. This hearing was continued to the June 22, 

2000 Board of Health meeting. The draft Sections 93 

and 94 were also scheduled for a hearing at the June 

22, 2000 Board of Health meeting. On June 22, 2000, 

the Clark County Board of Health amended Section 0 

and adopted Sections 90, 91, 92, 93, and 94. On July 

27, 2000, the Section 94 Handbook was scheduled for a 

public hearing by the Clark County Health District Board 

of Health on August 24, 2000. The Section 94 

Funding Constraints 

Prevent Attainment of 

the 24-Hour Standard 

Before 2006

Unpaved Roads 

Stabilization Adopted 

Dust Suppressant 

Specifications 

AQR Section 0 

Amended; Sections 

90, 91, 92, 93 and 94 

Adopted in 2000
 4-37 

Handbook was subsequently adopted at this meeting. 

The Clark County Health District Board of Health 

commenced a public comment period for Revised 

Sections 0 and 93 on September 28, 2000 and set a 

public hearing for November 16, 2000. The revised 

draft Sections 0 and 93 were adopted at the November 

16, 2000 meeting of the Clark County Health District 

Board of Health. Documentation of the public hearing 

and adoption process is in Appendix F. 

 

4.5 IMPLEMENTED CONTROL MEASURES 

4.5.1 Control Measure Terminology 

The terms emission reduction, rule penetration, rule 

effectiveness, and overall (rule) reduction are used 

throughout this overview of Clark County control 

measures. Emission reduction denotes the actual 

reduction that can be achieved when the control 

measure is properly applied to a specific activity or 

source. An example of emission reduction would be the 

percent reductions achieved when paving an unpaved 

road. The emission reduction is calculated by dividing 

the emissions that occur after the control measure is 

applied by the emissions that occur before the control 

measure is applied. 

Rule penetration is the percentage of a total source 

category that a particular rule will impact. Continuing 

with the road example, if the rule applies to roads 

having more than 150 vehicle trips per day, then the rule 

penetration would be the emissions generated by roads 

having more than 150 vehicle trips per day as a 

percentage of the emissions from all of the unpaved 

roads. 

The term “rule effectiveness” is somewhat misleading. 

Rule effectiveness is used to denote the rate of 

compliance with a rule. If, for example, operators of 

80 percent of a source category that is subject to a 

control measure requirement implement the control 

measure, and comply at all times with its requirements, 

then this “rule effectiveness” is said to be 80 percent. 

The overall reduction for a rule is calculated by 

multiplying the emission reduction by the rule 

Control Measure 

Terms Defined 

Rule Penetration 

Rule Effectiveness 

Default of 80 Percent 
 4-38 

penetration and multiplying the result by the rule 

effectiveness. This gives the overall emission reduction 

that is achieved by implementing the rule. 

4.5.2 Adopted Control Measures for the 24-Hour 

NAAQS 

Table 4-14 provides a detailed list of the specific 

elements of the Clark County control measures adopted 

or implemented to achieve attainment of the 24-hour 

PM10 NAAQS. 

Table 4-14 

Significant PM10 Sources Control Measures 24-Hour Standard 

Source 

Category BACM-Control Measures 

Overall 

Reduction 

Percentage 

with 

Control 

Measures 

Area Sources 

Disturbed 

Vacant Land 

• Prevent Motor Vehicle Access and Stabilize Disturbed 

Surface. {Section 90.2.1.1(a)} 

• Stabilize Disturbed Surface greater than 5,000 sq.ft. with 

Gravel or Dust Palliatives {Section 90.2.1.1(b)} 

• Discing or Blading areas of 5,000 square feet or larger for 

weed abatement, apply water both before and during 

operations {Section 90.2.2.1(a),(b)} 

• After Discing or Blading occurs, stabilize disturbed surfaces 

with Gravel, Water, Dust Palliatives, or Paving {Section 

90.2.2.1(c)} 

36% (2001) 

72% (2002+) 

Unpaved 

Parking Lots 

• Pave {Section 92.2.1.2(a)} 

• Apply and Maintain Dust Palliatives {Section 92.2.1.2(b)} 

• Apply and Maintain Dust Palliatives on Traffic Lanes and 

apply surface gravel to depth of two inches on Parking Areas 

{Section 92.2.1.2(c)} 

• (Proposed) Prohibition of new, unpaved parking lots 

• (Proposed) Prohibition of dust crossing property line 

Wind Erosion

36% (2001) 

72% (2002+) 

Vehicles 

24% (2001) 

48% (2002+) 

Construction 

Activity 

Fugitive Dust 

• Apply Dust Suppressant (water) throughout construction site 

to stabilize soil (Section 94 Handbook, CST 10-l) 

• Apply Dust Palliative on soils based on soil type (Section 94 

Handbook, CST 12) 

• Traffic Control in Construction Area {Section 94 Handbook, 

CST 10-2, CST 20-1, CST 19 Requirements & CST19-7)} 

• Use tarps or other suitable enclosures on haul truck 

(Section 94 Handbook, CST 13-1) 

34 % (2001) 

68 % (2003) 
 4-39 

Table 4-14 

Significant PM10 Sources Control Measures 24-Hour Standard 

(continued) 

Source 

Category BACM-Control Measures 

Overall 

Reduction 

Percentage 

with 

Control 

Measures 

Construction 

Activity 

Fugitive Dust 

(continued) 

• Stabilize surface with materials that will prevent track out of 

mud and dirt to the Paved section, with wheel shakers, wheel 

washers {Section 94 Handbook, CST 19-3, 19-4 and Section 

94.6.8.(c)} 

• Permits Required for Construction Activities (Section 94.4.1) 

• Public Information Signage Required (Section 94.4.5) 

• Site-Specific Dust Mitigation Plan Required for Projects of ten 

acres or greater in size (Section 94.4.9) 

• Dust Control Monitor Required for Construction Activity 

having 50 acres or more of actively Disturbed Soil (Section 

94.4.11) 

• 20% Opacity Limit on Dust Emissions {Section 94.5.2 & 

94.6.8(d)} 

• 100-yard Plume Limit {Section 94.6.8(b)} 

• (Proposed) 100-foot plume limit 

• (Proposed) Prohibition on dust crossing property line 

• Controls Required on site at all times, whether or not 

Construction Activity is occurring (Section 94.5.3) 

• Backfilling (Section 94 Handbook, CST 1) 

• Blasting – Abrasive (Section 94 Handbook, CST 2) 

• Blasting – Soil and Rock (Section 94 Handbook, CST 3) 

• Clearing and Grubbing (Section 94 Handbook, CST 4) 

• Clearing Forms (Section 94 Handbook, CST 5) 

• Crushing (Section 94 Handbook, CST 6) 

• Cut and Fill (Section 94 Handbook, CST 7) 

• Demolitions – Implosion (Section 94 Handbook, CST 8) 

• Demolitions – Mechanical/Manual (Section 94 Handbook, 

CST 9) 

• Disturbed Land Large Tracts (Section 94 Handbook, CST 11) 

• Dust Suppressant, Dust Palliative, and Surfactant Selection 

and Use (Section 94 Handbook, CST 12) 

• Landscaping (Section 94 Handbook, CST 14) 

• Paving/Subgrade Preparation (Section 94 Handbook, CST 

15) 

• Screening (Section 94 Handbook, CST 16) 

• Staging Areas (Section 94 Handbook, CST 17) 

• Stockpiles (Section 94 Handbook, CST 18) 

• Traffic – Construction Related (Section 94 Handbook, CST 

20) 

• Trenching (Section 94 Handbook, CST 21) 
 4-40 

Table 4-14 

Significant PM10 Sources Control Measures 24-Hour Standard 

 (continued) 

Source 

Category BACM-Control Measures 

Overall 

Reduction 

Percentage 

with Control 

Measures 

Construction 

Activity 

Fugitive Dust 

(continued) 

♦ Truck Loading (Section 94 Handbook, CST 22)100-yard 

Plume Limit {Section 94.6.8(b) 

♦ (Proposed) Prohibition on the use of dry rotary brushes or 

blower devices for cleanup of track out 

Windblown 

Construction 

Dust 

• Apply Dust Suppressant (water) throughout construction site 

to stabilize soil (Section 94 Handbook, CST 10-l) 

• Apply Dust Palliative on soils based on soil type (Section 94 

Handbook, CST 12) 

• Traffic Control in Construction Area (Section 94 Handbook, 

CST 10-2, CST 20-1, CST 19 Requirements & CST19-7) 

• Use tarps or other suitable enclosures on haul truck (Section 

94 Handbook, CST 13-1) 

• Stabilize surface with materials that will prevent track out of 

mud and dirt to the Paved section, with wheel shakers, 

wheel washers {Section 94 Handbook, CST 19-3, 19-4 and 

Section 94.6.8.(c)} 

• Permits Required for Construction Activities (Section 94.4.1) 

• Public Information Signage Required (Section 94.4.5) 

• Site-Specific Dust Mitigation Plan Required for Projects of 

ten acres or greater in size (Section 94.4.9) 

• Dust Control Monitor Required for Construction Activity 

having 50 acres or more of actively Disturbed Soil (Section 

94.4.11) 

• 20% Opacity Limit on Dust Emissions {Section 94.5.2 & 

94.6.8(d)} 

• 100-yard Plume Limit {Section 94.6.8(b)} 

• Controls Required on site at all times, whether or not 

Construction Activity is occurring (Section 94.5.3) 

• Backfilling (Section 94 Handbook, CST 1) 

• Blasting – Abrasive (Section 94 Handbook, CST 2) 

• Blasting – Soil and Rock (Section 94 Handbook, CST 3) 

• Clearing and Grubbing (Section 94 Handbook, CST 4) 

• Clearing Forms (Section 94 Handbook, CST 5) 

• Crushing (Section 94 Handbook, CST 6) 

• Cut and Fill (Section 94 Handbook, CST 7) 

• Demolitions – Implosion (Section 94 Handbook, CST 8) 

• Demolitions – Mechanical/Manual (Section 94 Handbook, 

CST 9) 

• Disturbed Land Large Tracts (Section 94 Handbook, CST 

11) 

• Dust Suppressant, Dust Palliative, and Surfactant Selection 

and Use (Section 94 Handbook, CST 12) 

36% (2001) 

71% (2002+) 
 4-41 

Table 4-14 

Significant PM10 Sources Control Measures 24-Hour Standard 

(continued) 

Source 

Category BACM-Control Measures 

Overall 

Reduction 

Percentage 

with 

Control 

Measures 

Windblown 

Construction 

Dust 

(continued) 

• Landscaping (Section 94 Handbook, CST 14) 

• Paving/Subgrade Preparation (Section 94 Handbook, CST 

15)Screening (Section 94 Handbook, CST 16) 

• Staging Areas (Section 94 Handbook, CST 17) 

• Stockpiles (Section 94 Handbook, CST 18) 

• Traffic – Construction Related (Section 94 Handbook, CST 

20) 

• Trenching (Section 94 Handbook, CST 21) 

• Truck Loading (Section 94 Handbook, CST 22) 

On-Road Mobile Sources

Paved Road 

Dust (includes 

Construction 

Track-Out) 

• Pave or Stabilize four feet of Shoulders (Section 93.2.1.1) 

• (Proposed) Stabilize eight feet of shoulders on new roads 

with 3,000 ADT or greater 

• Pave or Stabilize Medians with solid paving across median 

(Section 93.2.1.4) 

• Use PM-Efficient Street Sweepers (Section 93.2.3.1) 

• Establish routine frequent street sweeping programs 

• Prevent haul truck track out and spillage (Section 94 

Handbook, CSTs 13 & 22) 

• Prevent mud and dirt track out with wheel shakers, or wheel 

washers must be employed at Construction Sites to prevent 

mud and dirt track out onto paved roads (Section 94 

Handbook, CST 19-3 & CST 19-4) 

• Clean up mud and dirt track out at least once daily and when 

track out extends more than 50 feet 

N/A 13

Unpaved 

Road Dust 

• Pave Unpaved Roads With Traffic ≥ 150 ADT 

{Section 91.2.1.3(a)}; or

• Apply and Maintain Dust Palliatives to Unpaved Roads 

With Traffic ≥ 150 ADT {Section 91.2.1.3(b)}

Paving 

Phase-In 

(2001) -22% 

(2002) -44% 

(2003+)-65% 

 

 

13 No emission reductions taken for PM-Efficient Street Sweepers. Because there is not a linear relationship between silt loading 

and emission rates, the actual emission reductions will vary with the roadway mix in each inventory area. 
 4-42 

Table 4-14 

Significant PM10 Sources Control Measures 24-Hour Standard 

(continued) 

Source 

Category 

BACM-Control Measures 

Overall 

Reduction 

Percentage 

with 

Control 

Measures 

Highway 

Construction 

Project 

Activities 

• Apply Dust Suppressant (water) throughout construction site to 

stabilize soil (Section 94 Handbook, CST 10-l) 

• Apply Dust Palliative on soils based on soil type (Section 94 

Handbook, CST 12) 

• Traffic Control in Construction Area (Section 94 Handbook, 

CST 10-2, Section 20-1, CST 19 Requirements & CST19-7) 

• Use tarps or other suitable enclosures on haul truck (Section 

94 Handbook, CST 13-1) 

• Stabilize surface with materials that will prevent track out of 

mud and dirt to the Paved section, with wheel shakers, wheel 

washers {Section 94 Handbook, CST 19-3, 19-4 and Section 

94.6.8.(c)} 

• Permits Required for Construction Activities (Section 94.4.1) 

• Public Information Signage Required (Section 94.4.5) 

• Site-Specific Dust Mitigation Plan Required for Projects of ten 

acres or greater in size (Section 94.4.9) 

• Dust Control Monitor Required for Construction Activity having 

50 acres or more of actively Disturbed Soil (Section 94.4.11) 

• 20% Opacity Limit on Dust Emissions {Section 94.5.2 & 

94.6.8(d)} 

• 100-yard Plume Limit {Section 94.6.8(b)} 

• (Proposed) 100-foot plume limit 

• (Proposed) Prohibition of dust crossing property line 

• Controls Required on site at all times, whether or not 

Construction Activity is occurring (Section 94.5.3) 

• Backfilling (Section 94 Handbook, CST 1) 

• Blasting – Abrasive (Section 94 Handbook, CST 2) 

• Blasting – Soil and Rock (Section 94 Handbook, CST 3) 

• Clearing and Grubbing (Section 94 Handbook, CST 4) 

• Clearing Forms (Section 94 Handbook, CST 5) 

• Crushing (Section 94 Handbook, CST 6) 

• Cut and Fill (Section 94 Handbook, CST 7) 

• Demolitions – Implosion (Section 94 Handbook, CST 8) 

• Demolitions – Mechanical/Manual (Section 94 Handbook, CST 

9) 

• Disturbed Land Large Tracts (Section 94 Handbook, CST 11) 

• Dust Suppressant, Dust Palliative, and Surfactant Selection 

and Use (Section 94 Handbook, CST 12)

34% (2001) 

68% (2003)
 4-43 

Table 4-14 

Significant PM10 Sources Control Measures 24-Hour Standard 

(continued) 

Source 

Category BACM-Control Measures 

Overall 

Reduction 

Percentage 

with 

Control 

Measures 

Highway 

Construction 

Project 

Activities 

(continued)

• Landscaping (Section 94 Handbook, CST 14) 

• Paving/Subgrade Preparation (Section 94 Handbook, CST 

15)

• (Proposed) Prohibition on use of dry rolling brushes or 

blower devices for cleanup of track out

• (Proposed) Acquire only vacuum-type chip seal equipment 

• Screening (Section 94 Handbook, CST 16) 

• Staging Areas (Section 94 Handbook, CST 17) 

• Stockpiles (Section 94 Handbook, CST 18) 

• Traffic – Construction Related (Section 94 Handbook, CST 

20) 

• Trenching (Section 94 Handbook, CST 21) 

• Truck Loading (Section 94 Handbook, CST 22) 

Highway 

Construction 

Project-Wind 

Erosion 

• Apply Dust Suppressant (water) throughout construction site 

to stabilize soil (Section 94 Handbook, CST 10-l) 

• Apply Dust Palliative on soils based on soil type (Section 94 

Handbook, CST 12) 

• Traffic Control in Construction Area (Section 94 Handbook, 

CST 10-2, CST 20-1, CST 19 Requirements & CST19-7) 

• Use tarps or other suitable enclosures on haul truck (Section 

94 Handbook, CST 13-1) 

• Stabilize surface with materials that will prevent track out of 

mud and dirt to the Paved section, with wheel shakers, 

wheel washers {Section 94 Handbook, CST 19-3, 19-4 and 

Section 94.6.8.(c)} 

• Permits Required for Construction Activities (Section 94.4.1) 

• Public Information Signage Required (Section 94.4.5) 

• Site-Specific Dust Mitigation Plan Required for Projects of 

ten acres or greater in size (Section 94.4.9) 

• Dust Control Monitor Required for Construction Activity 

having 50 acres or more of actively Disturbed Soil (Section 

94.4.11) 

• 20% Opacity Limit on Dust Emissions {Section 94.5.2 & 

94.6.8(d)} 

• 100-yard Plume Limit {Section 94.6.8(b)} 

• Controls Required on site at all times, whether or not 

Construction Activity is occurring (Section 94.5.3) 

• Backfilling (Section 94 Handbook, CST 1) 

• Blasting – Abrasive (Section 94 Handbook, CST 2) 

• Blasting – Soil and Rock (Section 94 Handbook, CST 3)

36% (2001) 

71% (2002+)
 4-44 

Table 4-14 

Significant PM10 Sources Control Measures 24-Hour Standard 

 (continued) 

Source 

Category BACM-Control Measures 

Overall 

Reduction 

Percentage 

with 

Control 

Measures 

Highway 

Construction 

Project-Wind 

Erosion 

(continued) 

• Clearing and Grubbing (Section 94 Handbook, CST 4) 

• Clearing Forms (Section 94 Handbook, CST 5) 

• Crushing (Section 94 Handbook, CST 6) 

• Cut and Fill (Section 94 Handbook, CST 7) 

• Demolitions – Implosion (Section 94 Handbook, CST 8) 

• Demolitions – Mechanical/Manual (Section 94 Handbook, 

CST 9) 

• Disturbed Land Large Tracts (Section 94 Handbook, CST 

11) 

• Dust Suppressant, Dust Palliative, and Surfactant Selection 

and Use (Section 94 Handbook, CST 12) 

• Landscaping (Section 94 Handbook, CST 14) 

• Paving/Subgrade Preparation (Section 94 Handbook, CST 

15) 

• Screening (Section 94 Handbook, CST 16) 

• Staging Areas (Section 94 Handbook, CST 17) 

• Stockpiles (Section 94 Handbook, CST 18) 

• Traffic – Construction Related (Section 94 Handbook, CST 

20) 

• Trenching (Section 94 Handbook, CST 21) 

• Truck Loading (Section 94 Handbook, CST 22) 

Vehicle 

Erosion-Race 

Activities 

• Prevent Motor Vehicle Access and Stabilize Disturbed 

Surface {Section 90.2.1.1(a)}. 

• Stabilize Disturbed Surface greater than 5,000 sq.ft. with 

Gravel or Dust Palliatives {Section 90.2.1.1(b)}. 

40% (2001) 

79% (2002+) 

Wind ErosionRace 

Activities 

• Prevent Motor Vehicle Access and Stabilize Disturbed 

Surface {Section 90.2.1.1(a)}. 

• Stabilize Disturbed surface greater than 5,000 sq.ft. with 

Gravel or Dust Palliatives {Section 90.2.1.1(b)}. 

36% (2001) 

72% (2002+) 
 4-45 

4.5.2.1 Control Measures For Disturbed Vacant 

Lands (24-hour Standard)

4.5.2.1.1 Sources Controlled: 1) Publicly and privately 

owned disturbed open areas and vacant lots. 2) Weed 

abatement by discing and blading of open areas and 

vacant lots. 

4.5.2.1.2 Implementation Schedule: All requirements 

became effective on January 1, 2001. 

4.5.2.1.3 Description of Control Strategy: This 

control measure is implemented through Section 90 of 

the Air Quality Regulations. This regulation requires the 

implementation of controls for preventing fugitive dust 

emissions from disturbed open areas and vacant lots 

with a cumulative disturbed area larger than 5,000 

square feet, and for preventing fugitive dust emissions 

for weed abatement by discing and blading of open 

areas and vacant lots of 5,000 square feet or larger. 

An analysis of Clark County Assessor Records (See 

Appendix L) determined that less than one percent of 

vacant land within the BLM disposal boundary was from 

parcels smaller than 5,000 square feet. 

Control measures applicable to disturbed areas consist 

of the following: 

• Preventing motor vehicle access and stabilizing the 

disturbed surfaces; or 

• Applying dust palliatives to disturbed surfaces; or 

• Applying and maintaining a uniform surface gravel 

cover over the disturbed surfaces; or 

• Applying and maintaining alternative control 

approved by U. S. EPA. 

Where motor vehicle trespass is occurring on open 

areas and vacant lots greater than 5,000 square feet, 

regardless of the amount of cumulative disturbed 

surface area, owners must take steps to prevent 

trespass and stabilize the surface. Where greater than 

5,000 square feet of cumulatively disturbed surface 

exists, if owners have not implemented the latter control, 

they must apply dust palliative (not just water) or gravel. 

Prevention of Fugitive 

Dust Emissions 
 4-46 

Control measures for discing and blading consist of the 

following: 

• Applying water before and during discing and 

blading for weeds; and 

• Stabilizing after weed abatement. 

Test methods for determining compliance with the 

regulation’s stabilization requirements consist of the 

following: 

• Drop ball test; or 

• Threshold friction velocity test; or 

• Rock test method for non-erodible surface 

elements. 

4.5.2.1.4 Technical Feasibility and Environmental 

Impacts: Similar requirements for disturbed open areas 

and vacant lots, and for discing and blading, have been 

implemented in Maricopa County. The major difference 

between the Clark County regulatory program and the 

Maricopa County program is that the Clark County 

Regulations do not provide for revegetation as a control 

option. Revegetation was not considered to be a 

generally effective control option in the Las Vegas 

Valley due to the area’s meteorology. Rainfall occurs 

very sporadically in the Valley and averages only 4.13 

inches per year over an extended time period, as 

detailed in Chapter 3. This makes establishing selfsustaining vegetation generally infeasible as a method 

of controlling fugitive dust, unless special efforts are 

made to ensure adequate application of water and 

interim soil stabilization. However, the regulation does 

allow for revegetation and other control options not 

explicitly provided for in the regulation on a case-bycase basis, subject to approval by the Control Officer 

and the U. S. EPA Region IX Administrator. 

Use of windbreaks as a control measure for controlling 

dust from disturbed vacant lands are also subject to 

approval by the Control Officer and the U. S. EPA 

Region IX Administrator under this regulation. This 

allows for review of factors that may affect windbreak 

performance such as vehicular access, severity of soil 

disturbance, and windbreak orientation. 

 

Revegetation Not a 

Control Option

Windbreaks as a 

Control Measure
 4-47 

Clark County is proposing to amend AQR Section 90 to 

require large property owners managing 10,000 acres or 

more to develope vacant land stabilization plans. For 

example, BLM is using satellite data to identify parcels 

with potential disturbance and hiring an employee to 

routinely inspect parcels. Nellis Air Force Base has 

hired a consultant to test their parcels and develop an 

inspection plan. The public works departments from the 

various entities have also been contacted by AQD staff 

and are beginning to develop plans of their own. These 

voluntary measures allow the AQD staff to prioritize the 

property owners and work with the owners of the largest 

number of acres first. 

The controls of choice under this regulation will 

generally be vehicular access controls and the 

application of dust suppressants. A number of classes 

of dust suppressant products are in large-scale use both 

in the Las Vegas Valley and throughout the United 

States. They are generally considered to be 

environmentally innocuous. However, field and 

laboratory studies evaluating the long-term potential 

adverse impacts of these products on soil and water are 

limited, and no studies to evaluate these impacts have 

been conducted to date in the Las Vegas Valley. 

Because it is recognized that the requirements set forth 

in this regulation will significantly increase the use of 

these dust suppressant products, Clark County has 

committed to facilitating and participating in research to 

address these issues. The SIP commitment for this 

research is in Section 4.8.2.1. 

One environmental impact of commonly used dust 

suppressant materials is the decrease in the 

permeability of treated soil surfaces and, as a result, 

increased water runoff during storm events. Although 

the products protect treated areas from water erosion 

and reduce downstream siltation from these areas, the 

increased surface flow may result in additional flood 

potential downstream. The CCDCP will work with the 

Clark County Flood Control District to further evaluate 

these impacts. 

4.5.2.1.5 Emission Reductions: All emission reduction 

computations are based on the 2006 attainment year for 

the 24-hour NAAQS. The control measure applies 

Dust Suppressants as 

a Control Measure 

Water Runoff a 

Concern with the Use 

of Dust Suppressants
 4-48 

to the PM10 emission source category “Disturbed Vacant 

Lands/Unpaved Parking Lots” with a total of 19.3 tons 

per day of uncontrolled PM10 emissions coming from 

976 acres of disturbed vacant land. Control measures 

and emission reductions for unpaved parking lots are 

addressed under the unpaved parking lots section. The 

emission reduction, rule penetration, rule effectiveness, 

and overall reduction for this control measure are 

detailed in Appendix L, Table L-2, and are shown below: 

• Emission Reduction 91 percent; 

• Rule Penetration 99 percent; 

• Rule Effectiveness 80 percent; and 

• Overall Control Reduction 72 percent; 

Applying these overall control reductions to the 2006 

uncontrolled emissions for this source category yields 

the following emission reductions: 

• Baseline Emissions: 19.3 TPD 

• Controlled Emissions: 13.9 TPD 

• Emission Reductions: 5.4 TPD 

4.5.2.1.6 Control Measure Costs: A range of costs has 

been calculated for this control measure due to the 

following factors: 

• The rule allows a number of alternative control 

options that may differ widely in cost; 

• The cost for a given option may vary 

considerably with the size of area to be treated 

and onsite impacts such as vehicular traffic; and 

• Specific site conditions, such as soil type 

may significantly impact costs. 

The following control measure cost and assumptions 

were utilized in developing cost effectiveness estimates: 

• Fencing Cost14 –Acre per year (based on cost of 

renting fencing): $2,000; 

• Stabilization Cost15 – Acre per application: $500 

to $1,500; 

 

14 Memorandum #08-00 to Clark County Health District Board of 

Health, May 25, 2000 

15 Ibid 

Disturbed Vacant Land 

Control Measure 

Effectiveness

Stabilizing Unstable 

Vacant Land Is a CostEffective Control 

Measure
 4-49 

• Number of Applications per year: one to three 

(assume less expensive material will need to be 

applied more frequently); 

• Cost Range per acre per year: $500 to $2,000; 

and 

• Cost of Enforcement: $540,540. 

The public cost of enforcement must also be considered 

when calculating control measure cost effectiveness. 

As noted in the discussion of commitments for additional 

Air Quality Division (AQD) enforcement staffing levels in 

this chapter, the total cost per year of this expanded 

effort, with the exception of certain administrative costs, 

is $780,000.16 Administrative costs are assumed to be 

ten percent. It is anticipated that 63 percent of the 

enhanced enforcement effort will be applied to disturbed 

vacant land compliance. It is estimated that the total 

enforcement cost per year attributed to this control 

measure will be $540,540.17

The number of acres of disturbed open areas or vacant 

lots, including unpaved parking lots, that are subject to 

these controls are estimated to be 976 acres in the 2006 

24-Hour Valley-Wide Emission Inventory (Table E-9). 

This acreage is multiplied by the low and high control 

cost per acre ($500 and $2000) to calculate the control 

measure cost per year. Enforcement cost per year is 

added to the low and high control costs to get the total 

control costs range per year. These total costs were 

divided by 365 to get the low and high end total control 

cost per day. Dividing these numbers by the emission 

reductions achieved (5.4 tons per day) yields the cost 

effectiveness for this control measure. 

The Clark County Health District Board of Health has 

adopted Section 90 of the Air Quality Regulations as 

RACM and BACM for this emission source category. 

 

16 Naylor, M.H., Workplan for PM10 Resources Commitment, 

Prepared for Clark County Health District Board of Health, July 11, 

2000. 

17 The estimated cost for enforcing Section 90 is based on the 

assumption that 63 percent of the new enforcement cost will be 

allocated to Section 90. Unaccounted administrative costs are 

estimated to be 10 percent of the operational cost. Therefore, 

Section 90 enforcement costs are calculated as follows: 

$780,000x0.63x1.10=$540,540. 
 4-50 

Low High 

Control 

Measure 

Cost/Year 

$488,000 $1,952,00 

Enforcement 

Cost/Year $540,540 $540,540 

Total Control 

Cost/Year $1,028,540 $2,492,540 

Total Cost Per 

Day $2,818 $ 6,829 

Cost 

Effectiveness 

$522 

per ton 

$1,265 

per ton 

4.5.2.2 Control Measures For Unpaved Parking Lots 

(24-Hour Standard)

4.5.2.2.1 Sources Controlled: Unpaved parking lots. 

4.5.2.2.2 Implementation Schedule: Control 

measures must be applied to new parking lots 

constructed after June 22, 2000. Control measures 

must be applied to existing parking lots by July 1, 2001. 

4.5.2.2.3 Description of Control Strategy: This 

regulation requires the implementation of controls for 

preventing fugitive dust emissions from unpaved parking 

lots that are used for parking, maneuvering, or storing 

motor vehicles. Parking lots that are utilized 

intermittently, for a period of 35 days or less during the 

calendar year, may implement the controls set forth in 

this regulation only during the period that the parking lot 

is utilized for vehicle parking. It should be noted, 

however, that an intermittent-use parking lot would 

become subject to Section 90 of the Air Quality 

Regulations during periods the lot was not utilized for 

vehicle parking. 

Control measures applicable to unpaved parking lots 

consist of the following: 

• Paving; or 

• Applying and maintaining dust palliatives; or 

Unpaved Parking 

Lots Control 

Measures 
 4-51 

• Applying and maintaining dust palliatives on 

traffic lanes and applying and maintaining 

surface gravel to a depth of two inches on the 

parking areas; or 

• Applying and maintaining alternative controls 

approved by U. S. EPA. 

Stabilization standards include the following: 

• Complying with a 20 percent opacity requirement; 

and

• Maintaining silt loading of no more than 0.33 

ounces per square foot; or 

• Maintaining silt content of no more than eight 

percent. 

Test methods for determining compliance with the 

control measures and stabilization standards include an 

opacity test method and a silt content test method. 

4.5.2.2.4 Technical Feasibility and Environmental 

Impacts: The control measures and stabilization criteria 

required under this regulation have been implemented 

in Maricopa County. The Clark County regulation does 

not permit the use of gravel as a control measure for 

travel lanes in unpaved parking lots. The requirement 

that gravel be maintained at a depth of two inches is 

also unique to the Clark County Regulation. The total 

area of unpaved parking lots is relatively small and 

these facilities were therefore inventoried with disturbed 

open areas. This was done in part because of the 

difficulty in differentiating between unpaved parking lots 

and disturbed open areas in many cases. For those 

unpaved parking facilities that are utilized on a regular 

basis, paving will probably be the most cost-effective 

option. It is also expected that in response to the 

adoption of Section 92, land use planning agencies will 

not be able to issue variances for paving requirements 

for future development projects. Where paving 

requirements have been previously deferred, it is not 

anticipated that additional deferrals will be granted for 

existing projects, given the fact that the Section 92 

requirements supersede the County and Local Planning 

Code requirements. 

Thus, increased use of dust suppressant products 

Paving Most CostEffective Option 
 4-52 

under the provisions of this regulation is expected to be 

limited. Dust suppressant products would primarily be 

limited to intermittently used parking facilities and other 

existing unpaved parking facilities as an interim 

compliance measure until more permanent and costeffective paving can be financed. 

4.5.2.2.5 Emission Reductions: Because the extent of 

unpaved parking lots affected by this regulation has not 

been determined on a valley-wide basis, emission 

reductions from this regulation have been calculated 

using acreage of unpaved parking from the two “worst 

case” micro-scale areas that contained unpaved 

parking. A total of 21 acres of unpaved parking was 

found in the Pittman micro-scale area and 18 acres of 

unpaved parking was found in the Craig Road microscale area. The emission reductions, rule penetration, 

rule effectiveness, and overall reduction are detailed in 

Appendix L and shown below: 

• Emission Reductions-Wind: 91 percent; 

• Emission Reductions-Vehicle: 60 percent; 

• Rule Penetration-Wind: 99 percent; 

• Rule Penetration-Vehicle: 100 percent; 

• Rule Effectiveness-Wind: 80 percent; 

• Rule Effectiveness-Vehicle: 80 percent; 

• Overall Reduction-Wind : 72 percent; and 

• Overall Reduction-Vehicle: 48 percent. 

Applying these overall control reductions to the 

calculated emissions from the 39 acres of unpaved 

parking in the two inventory areas yields the following 

emission reductions: 

• Baseline Emissions (Wind): 1.62 TPD; 

• Controlled Emissions (Wind): 0.45 TPD; 

• Emission Reductions (Wind): 1.17 TPD; 

• Baseline Emissions (Vehicle): 0.034 TPD; 

• Controlled Emissions (Vehicle): 0.018 TPD; 

and 

• Emission Reductions (Vehicle): 0.016 TPD. 

4.5.2.2.6 Control Measure Costs: A range of costs 

has been calculated for this control measure due to the 

following factors: 

Use of Dust 

Suppressants Will Be 

Limited

Emission Reductions 

Calculated from 

“Worst Case” Areas 
 4-53 

• The rule allows several alternative control options 

that may differ significantly in cost; 

• The cost for a given option may vary considerably 

with the size, frequency of use, and intensity of use 

of the parking lot to be treated; and 

• Specific site conditions, such as soil type, may 

significantly impact costs. 

The following control measure costs per acre and 

assumptions were utilized in developing cost 

effectiveness estimates: 

• Annual Control Measure Cost (Paving): 

 $1,722 to $4,300; 

• Annual Control Measure Cost (Dust Palliatives): 

 $1,000 to $2,000; and 

• Annual Control Cost Range: 

 $1,000 to $4,300. 

The public cost of enforcing the requirements for 

unpaved parking lots cannot be accurately separated 

from the cost of compliance enforcement of disturbed 

open areas and vacant land, but are expected to be a 

relatively small part of the $540,540 annual enforcement 

cost for this source category. The public cost of 

compliance enforcement is, therefore, not considered in 

this cost assessment for unpaved parking lots. 

The cost effectiveness of this control measure for windgenerated emissions is calculated as follows. The 

number of acres of unpaved parking lots from the microscale areas is 39 acres. This acreage is multiplied by 

the low and high annual control cost per acre ($1000 

and $4,300) to get the control measure cost per year. 

This control cost is divided by 365 to get the low and 

high end control cost per day. Dividing these numbers 

by the wind erosion emission reductions achieved (1.17 

tons per day) gives the low and high end cost 

effectiveness from this control measure for wind erosion 

emissions. 

Low High 

Control Measure 

Cost/year $39,000 $167,700 

Control Measure 

Cost/day $106.85 $459.45 

Emission Reductions 1.17 TPD 1.17 TPD 

Cost Effectiveness $91 per ton $393 per ton 
 4-54 

The cost effectiveness of this control measure for 

vehicle-generated emissions is calculated as follows. 

The number of acres of unpaved parking lots from the 

micro-scale areas is 39 acres. This acreage is 

multiplied by the low and high annual control cost per 

acre ($1000 and $4,300) to get the control measure cost 

per year. This control cost is divided by 365 to get the 

low and high end control cost per day. Dividing these 

numbers by the vehicle-generated emission reductions 

achieved (0.016 tons per day) gives the low and high 

end cost effectiveness from this control measure for 

vehicle-generated emissions. 

Low High 

Control Measure 

Cost/year $39,000 $167,700 

Control Measure 

Cost/day $106.85 $459.45 

Emission Reductions 0.016 TPD 0.016 TPD 

Cost Effectiveness $6,678 per 

ton 

$28,716 per 

ton 

The Clark County Health District Board of Health has 

adopted Section 92 of the Air Quality Regulations as 

RACM and BACM for this emission source category.

4.5.2.3 Control Measures For Construction Activities 

(24-hour Standard)

4.5.2.3.1 Sources Controlled: Construction activities 

and related emissions. 

4.5.2.3.2 Implementation Schedule: These control 

measures must be implemented on construction sites 

beginning on January 1, 2001. 

4.5.2.3.3 Description of Control Strategy: Primary 

elements of the control measures set forth in Section 94 

of the Air Quality Regulations and the companion 

Section 94 Handbook for Best Management Practices 

(BMP) are the use of site-specific and phase-specific 

dust control plans and activity-specific and soil-specific 

control measure options for each dust-generating 

activity. This regulatory program is designed to facilitate 

pre-planning for dust control and the integration of dust 

Controlling Dust from 

Construction Activities 
 4-55 

control activities with other work at construction sites 

while allowing the flexibility to employ the best and most 

cost-effective control measures for each specific job 

site. Clark County staff believes that this regulatory 

program provides a major advancement over other 

programs that have been implemented to regulate 

fugitive dust from construction activities and sets the 

BACM/Most Stringent Measure benchmark. 

Section 94 of the Air Quality Regulations (Section 94) 

contains specific regulatory requirements, including 

permit requirements, stabilization requirements, 

administrative requirements, and performance 

standards. The Section 94 Handbook is a 

compendium of BMP that has been approved by the 

Clark County Board of Health for controlling dust from 

construction activities under varying site-specific 

conditions. Implementing the appropriate BMPs 

contained in the Section 94 Handbook will result in 

compliance with the rule; and the Section 94 Handbook 

methodologies and procedures will be the basis for 

enforceable dust permit conditions. 

This regulatory program is the result of the cumulative 

efforts of the Advisory Committee, the Clark County 

Board of Health, the construction industry coalition, 

CCDCP staff, AQD staff, and the U. S. EPA. It 

represents a successful example of what can be 

achieved through a consensus-based regulatory 

development process. The Advisory Committee 

finalized a Request for Proposals (RFP) for review of 

the Clark County Health District air quality program and 

development of BMP for construction activities in July 

1999. Proposals for this work were accepted through 

August 27, 1999 and the Advisory Committee 

recommended that the firm of Dames & Moore be 

retained to perform this work on September 10, 1999. 

The Clark County Board of Health approved this 

recommendation. The construction industry was 

interviewed by Dames & Moore and provided many 

insightful comments on the current regulatory program. 

The Advisory Committee provided assistance in the 

development of BMP for controlling dust. The Advisory 

Committee accepted the Dames & Moore reports as 

complete on May 5, 2000 and the 

BMP for Construction 

Activities Developed 
 4-56 

Clark County Board of Health accepted these reports on 

May 25, 2000. Section 94 of the Air Quality 

Regulations and the companion Section 94 Handbook 

for BMP implement the concepts and the control 

measures recommended in the Dames & Moore reports. 

The Section 94 Regulation includes the following permit 

requirements for construction activities: 

• Dust control permits are required for construction 

activities on sites of 0.25 acres or larger; or 

• Trenching projects of 100 feet or greater in 

length; or 

• Demolition of structures 1,000 square feet or 

larger; and 

• A dust control permit and a site-specific dust 

mitigation plan is required for construction 

activities on sites of ten acres or more. 

As noted above, a site-specific dust mitigation plan must 

be provided for all construction projects of ten acres or 

greater. For projects of less than ten acres, a sitespecific dust mitigation plan is not required, but 

appropriate BMPs from the Section 94 Handbook must 

be incorporated into the permit application and 

approved by AQD staff. Where dust mitigation plans 

are submitted, the plans are subject to review and 

approval by AQD staff. The regulation also obligates 

permit holders to ensure that contractors and 

subcontractors abide by the conditions of the approved 

dust control permit and dust mitigation plan. For a 

further description of the dust control plan and permit 

requirements, see Section 6.3.3.3. 

Section 94 implements the following general 

requirements and standards for construction activities: 

• Posting signs which advise the public who to call 

in the event of a dust problem and where to call 

to report a dust violation; and

• Employing Best Management Practices (BMP) 

from the Section 94 Handbook as specified in the 

approved dust control permit and dust mitigation 

plan; and 

General 

Requirements for 

Construction 

Activities
 4-57 

• Requiring a dust control coordinator (monitor) for 

construction projects having 50 acres or more of 

actively disturbed area; and 

• Handling, transporting, or storing material in a 

manner that prevents dust plumes from 

exceeding 20 percent opacity; and

• Maintaining disturbed soil in a condition to 

minimize wind erosion and particulate emissions 

24 hours a day, seven days a week; and

• Ceasing construction activities when wind 

conditions cause dust emissions to exceed 20 

percent opacity; and

• Maintaining dust control until the construction site 

is completely stabilized by landscaping, paving, 

or the application and maintenance of a dust 

palliative or other effective long-term stabilization; 

and

• Notifying the AQD within ten days after 

completion of a construction project in order to 

allow the AQD to verify that stabilization 

requirements have been met.

Section 94 contains the following enforcement 

standards and requirements: 

• Requires a surety bond to cover the cost of the 

dust control measures when three or more 

violations occur within 180 days; and 

• Establishes that non-compliance with BMP as set 

forth in the approved dust control permit or dust 

mitigation plan is a violation of the AQD’s 

regulations; and 

• Provides that a permit may be revoked or 

suspended when three notices of violation have 

been issued; and 

• Establishes that generation of a dust plume 

extending more than 100 yards is a violation; and 

• Establishes that the failure to immediately clean 

up mud and dirt that is tracked out onto a paved 

road and that extends a cumulative distance of 

50 feet or more, or the failure to clean up any 

track out by the end of the work day, is a 

violation; and 

• Establishes that allowing a dust plume to exceed 

an opacity of 20 percent is a violation; and 

• Establishes that failure to maintain project soils 

Section 94 

Enforcement 

Standards and 

Requirements 
 4-58 

with adequate crusting is a violation; 

• Provides that the Clark County Control Officer 

may, after giving due notice, take appropriate 

corrective action to remedy a dust problem where 

the owner or operator fails to do so and assess 

the cost to the responsible party; and 

• (Proposed) Establishes that the generation of a 

dust plume more than 100 feet is a violation. 

Section 94 also contains the following miscellaneous 

and administrative requirements: 

• Construction site superintendents or designated 

alternatives and water truck operators are 

required to attend the AQD dust control class 

every three years; and 

• Records of construction site self-inspections must 

be kept for one year or for a six-month period 

following the project’s completion, whichever is 

longer; and 

• Where chemical or organic soil stabilizers are 

applied, records must indicate the type of product 

applied, vendor name, and label instructions for 

approved usage; and the method, frequency, 

concentration, and quantity of application. 

Test methods contained in Section 94 for determining 

compliance with the control measures and stabilization 

standards consist of an opacity test method and a drop 

ball test method. Clark County has contracted with 

Converse Consultants to develop and field-test 

improved alternative test methods for monitoring visible 

emissions. 

The Section 94 Handbook of Best Management 

Practices for Dust Control grew out of efforts to define 

what control measures were appropriate for different 

construction activities within the Las Vegas Valley. Due 

to differences in soil types and the need to control water 

usage, a “one size fits all” approach was not considered 

effective and had not worked well in the past. The 

Section 94 Handbook provides BMPs for dust control 

that are activity-specific and which may be implemented 

on a site-specific and phase-specific basis, considering 

the type of soil at a particular site or location and the 

soils’ potential to emit fugitive dust. Currently , AQD 

Section 94 

Miscellaneous and 

Administrative 

Requirements

Section 94 Handbook 

Defines Dust Control 

Measures for Different 

Construction Activities
 4-59 

staff are working to develop dust mitigation recordkeeping forms that are easy to use, yet detailed enough 

to demonstrate compliance with each site-specific dust 

mitigation plan. When finalized, these forms will be 

incorporated into the Section 94 Handbook. The 

regulatory requirements for construction activities are 

contained in Section 94 of the Air Quality Regulations 

and are described above. 

In the Section 94 Handbook, soil types are classified 

into five categories (high, moderately high, moderately 

low, low, and slight) based on their Particulate Emission 

Potential (PEP). PEP is determined by soil silt content 

(measured by the soil percentage that will pass through 

a 200-mesh sieve) and optimum moisture content for 

compaction (measured by the percent moisture 

necessary to maximize compaction of the soil). The 

Section 94 Handbook contains a decision flow chart 

using these two parameters, optimum moisture content 

and silt content, to calculate PEP for Las Vegas soils. 

Maps of Clark County and Las Vegas that delineate the 

five PEP categories are included in the Handbook for 

projects where the optimum moisture content or silt 

content is not known. Use of site-specific geotechnical 

reports or preliminary soil studies are highly encouraged 

when developing dust mitigation plans for submittal to 

the AQD. 

Subsections of the Section 94 Handbook list the BMP 

alphabetically by construction activity and then by soil 

PEP category. Within most construction activity 

categories there are multiple BMP options which may be 

implemented to meet the Section 94 requirements for 

each activity. All BMPs for each activity that will occur 

at a construction site must be identified in the dust 

mitigation plan submitted to the AQD or will be specified 

in the dust control permit that is issued by AQD for the 

construction project. Dust mitigation plans must be 

approved by the AQD prior to the issuance of a dust 

control permit. The BMP selected to meet the 

requirements of Section 94 must take into account the 

soil PEP for the area in which the construction activity 

will occur. 

The following categories of construction activities are 

covered by BMP: 

Soil Types 

Described in 

Section 94 

Handbook

BMPs Must Be 

Identified for Dust 

Mitigation Plans 
 4-60 

• Backfilling; 

• Blasting – Abrasive; 

• Blasting – Soil and Rock; 

• Clearing and Grubbing; 

• Clearing Forms; 

• Crushing Operations; 

• Cut and Fill Operations; 

• Demolition – Implosion; 

• Demolition – Mechanical/Hand; 

• Disturbed Soil; 

• Disturbed Land – Large Tracts; 

• Dust Suppressant, Dust Palliative, and Surfactant 

Selection and Use; 

• Importing Soil, Rock, and Other Bulk Materials; 

• Landscaping; 

• Paving/Subgrade Preparation; 

• Screening; 

• Staging Area; 

• Stockpiles; 

• Track Out Prevention; 

• Traffic – Construction Related; 

• Trenching Operations; and 

• Truck Loading. 

Control measures not currently listed in the Handbook 

may be proposed in the dust mitigation plan. Such 

measures will be reviewed by the District’s staff and 

evaluated according to the following criteria: 

• The control technique is a new or alternative 

technology that has been shown to be of equal or 

greater effectiveness in meeting the requirements 

than the existing BMP; or 

• Site logistics do not permit the implementation of 

the control measure as written; or 

• The owner/operator demonstrates that the control 

measure is technically infeasible due to sitespecific or material-specific conditions in that its 

implementation will not reduce fugitive dust 

emissions. 

At least one of the above criteria must be met before 

permit deviations from specific soil category BMPs are 

allowed. 

Non-Listed Control 

Measures May Be 

Proposed and 

Evaluated 
 4-61 

4.5.2.3.4 Technical Feasibility and Environmental 

Impacts: The regulatory approach implemented by this 

regulation has been utilized for controlling emissions 

from stationary sources for many years, but has not 

been applied to area-source fugitive dust emissions until 

now. The regulation implements site-specific permitting 

for large construction sites. The permitting process is 

designed to allow flexibility in crafting a dust 

control plan while ensuring that appropriate control 

measures are applied to all dust-producing activities 

associated with a construction project. Clark County 

believes that this regulatory approach will lead to future 

improvements to dust control technology in the same 

way that this regulatory approach has facilitated 

improved control technology for stationary sources. 

In order to facilitate rule implementation and encourage 

development of improved methods of dust control for 

construction activities, the AQD has committed to 

reviewing and, as appropriate, updating the Section 94 

Handbook every six months. 

All of the BMPs provided in the Section 94 Handbook 

have been effectively employed by the construction 

industry in either the Las Vegas Valley or other parts of 

the southwestern United States. The unique component 

of the Section 94 Handbook is the soil characterizations 

used to predict a soil’s PEP category. This was 

developed utilizing data from 150 soil samples. Since 

its publication in the Dames & Moore reports, PEP 

categorization has been employed by the construction 

industry in the Las Vegas Valley and has been found by 

the industry to accurately reflect the potential severity of 

fugitive dust emissions and a soil’s response to various 

control measures. County staff also observed the 

comparative dustiness of unpaved roads in the Las 

Vegas Valley and found that the relative dustiness of the 

road tracked the PEP category of the road surface. 

However, County staff believes that additional 

refinement of the PEP index would be desirable. If 

feasible, County staff may collaborate with the research 

scientists who developed the PEP concept in publishing 

a paper in a peer-reviewed 

Permitting Process 

Allows Flexibility in 

Dust Control Plan 

This Approach Will 

Lead to Future 

Improvements in Dust 

Control

AQD Will Update 

Handbook Every Six 

Months 

Handbook’s PEP 

Categories a Unique 

Factor 

County Believes 

Additional Refinement 

of PEP Categories 

Desirable 
 4-62 

scientific journal. In addition to getting the concept peer 

reviewed, and increasing our knowledge base, a journal 

article would facilitate the utilization of the PEP concept 

in other nonattainment areas. 

This regulation will result in the increased use of dust 

palliatives in the Las Vegas Valley. In addition, the 

regulation will require significant increases in the 

amount of surfactants and tackifiers that are applied 

during land clearing, grubbing, and earth-moving 

operations. The potential impacts of this increased use 

of dust palliatives and suppressants in the Las Vegas 

Valley are detailed above under the review of disturbed 

vacant land. As described under the SIP commitments 

section in this chapter, Clark County is committed to 

participating in the funding and coordination of research 

to determine the potential adverse environmental 

impacts from the long-term use of dust suppressant 

materials. 

4.5.2.3.5 Emission Reductions: All emission reduction 

computations are based on the 2006 attainment year for 

the 24-hour NAAQS. The rule applies to the PM10

emission source categories, “Construction Activity 

Fugitive Dust” and “Windblown Construction Dust.” 

“Highway Construction Activity Fugitive Dust” and 

“Highway Construction Projects-Wind Erosion” were 

broken out separately from other construction activities 

in the Chapter 3 emission inventories for transportation 

conformity purposes, but have been included with the 

other construction activities for the purposes of this 

analysis. Control factors for highway-related 

construction activities are identical to those for other 

types of construction. This control measure applies to 

all of Clark County, so the actual reductions achieved 

are greater than those applicable to the Las Vegas 

Valley and factored into the attainment demonstration. 

The emission reductions, rule penetration, rule 

effectiveness, and overall reduction for the year 2006 

are shown below. 

Emission Reductions: 

• Construction Activity Fugitive Dust: 87 percent 

• Windblown Construction Dust: 91 percent 

Dust Palliative Use 

Will Increase in Valley 

Emission 

Reductions 

Quantified for 

Several Categories
 4-63 

Rule Penetration: 

• Windblown Construction Dust: 98 percent 

• Construction Activity Fugitive Dust: 98 percent; 

Rule Effectiveness (2006): 

• Construction Activity Fugitive Dust: 80 percent 

• Windblown Construction Dust: 80 percent 

Overall Reduction (2006): 

• Construction Activity Fugitive Dust: 68 percent 

• Windblown Construction Dust: 71 percent 

Applying these overall control reductions to the 

uncontrolled emissions from the 14,587 acres under 

construction in 2006 (Table E-5) provides the controlled 

emissions and emission reductions shown below for this 

source category: 

• Baseline Emissions (Activity): 45.6 TPD; 

• Controlled Emissions (Activity): 14.6 TPD; 

• Emission Reductions (Activity): 31.0 TPD; 

• Baseline Emissions (Wind): 97.5 TPD; 

• Controlled Emissions (Wind): 29.4 TPD; 

and 

• Emission Reductions (Wind): 68.1 TPD. 

4.5.2.3.6 Control Measure Costs: Dames & Moore18

found that the cost of controlling dust during grading on 

a 40-acre parcel with soils categorized as “Low” for PEP 

would typically be $1,700 per day, or $43 per acre per 

day. This cost is predicated on the application of 

200,000 gallons of water. The water application rate 

and cost would double for a parcel with soils classified 

as “High” for PEP. Therefore, the cost per acre per day 

for controlling dust from grading operations ranges from 

$43 per acre per day to $86 per acre per day. The 

projected acreage of construction occurring valley-wide 

in 2006 is 14,587 acres as shown in Appendix E, Table 

E-5. However, not all of this construction acreage is 

active during the entire year as discussed in Appendix 

B. Using the average length of construction by type of 

construction project, the number of acres on any given 

 

18 Dames & Moore, An Evaluation of Incorporating Best 

Management Practices into the Construction Activities Program, 

document 44499-001-128, prepared for the Clark County Health 

District Board of Health, p. 13. 

Costs of Controlling 

Dust
 4-64 

day can be calculated. The acreage under construction 

in 2006 is 225 acres. 

Grading is the most dust-intensive phase of a 

construction project. Cost estimates for dust control 

during other phases of a construction project under this 

control measure have not been developed by industry 

and are currently not known. Once cost factors have 

been developed by industry for compliance, a more 

complete cost analysis can be completed. Because of 

the unavailability of cost factors for other requirements 

in the control measure, the cost analysis for this control 

measure is based on cost effectiveness per acre for 

control of dust from grading operations and will 

overestimate the compliance cost for most other types 

of construction activities. 

The cost of enforcement to the local air agency is 

calculated as follows. The cost of additional AQD 

enforcement staffing levels for the implementation of 

this regulation is calculated to be $285,714.19 The perday enforcement cost is calculated by dividing this figure 

by 365, and is approximately $783. 

The cost of compliance is calculated by multiplying the 

cost per day of control by the number of acres per day 

that must be controlled each day. The low and high 

control costs range is calculated as follows: 

Low Cost: $43 x 225 acres/day = $9,675 

High Cost: $80 x 225 acres/day = $19,350 

Adding the cost per day of enforcement to the total low 

and high cost of controls gives the total cost of 

implementing the control measure. These low and high 

costs for control measure implementation are $10,458 

and $20,132 respectively. Dividing the total control 

measure implementation cost by the emission 

reductions achieved by the control measure gives the 

cost effectiveness for the control measure. 

 

19 The estimated cost for enforcing Section 94 is based on the 

assumption that 33 percent of the new enforcement cost will be 

allocated to enforcing Section 94. Unaccounted administrative 

costs are estimated to be 10 percent of the operational cost. 

Therefore, Section 90 enforcement costs are calculated as follows: 

$780,000x0.3x1.10=$285,714 

 
 4-65 

These values are set forth below: 

Low High 

Total Cost Per Day $10,458 $20,132 

Emission 

Reductions (Wind 

and Activity) 

99.1 99.1 

Cost Effectiveness $106 per ton $203 per ton 

The Clark County Health District Board of Health has 

adopted Section 94 of the AQR as RACM and BACM for 

this emission source category. 

4.5.2.4 Control Measures For Paved Road Dust (24-

Hour Standard)

4.5.2.4.1 Sources Controlled: Paved roads 

4.5.2.4.2 Implementation Schedule: The 

requirements of these control measures became 

effective on January 1, 2000. 

4.5.2.4.3 Description of Control Strategy: These 

control measures set requirements for design standards 

for paved road shoulders and medians and set PM 

efficiency requirements for street sweeping equipment. 

The control measures for unpaved shoulders and street 

sweeping equipment are implemented under Section 93 

of the AQR. The control measure for reducing track out 

of mud and dirt from construction sites onto paved 

roads is implemented under Section 94 of the AQR. 

The purpose of the shoulder and median design 

requirements is to reduce silt loading on paved road 

travel lane surfaces from mud and dirt track on. The 

U. S. EPA Fugitive Dust BACM guidance document20

suggests that other benefits from shoulder or curb 

improvements are reductions in the transfer of dust from 

exposed road shoulders to road surfaces by vehicle 

turbulence, wind erosion, and water erosion. An 

authoritative peer-reviewed study conducted by the 

Desert Research Institute in Merced County, California, 

found that the actual entrainment occurring from vehicle 

wakes was limited and was only measurable from large 

 

20 Fugitive Dust Background Document, supra, p 3-11 

Paved Road Dust 

Control Measures 
 4-66 

vehicles traveling at 50 to 60 mph.21 The primary 

emphasis of these paved road design standards is, 

therefore, prevention of mud and dirt track out on to the 

travel lanes of paved road surfaces. 

The regulation requires paving or stabilization of fourfoot shoulders beyond the travel lane or the installation 

of curbs adjacent to the paved section of road. The 

regulation also requires that medians be paved or 

stabilized, or be constructed with curbing. Most 

medians constructed in the Las Vegas Valley 

already comply with this standard. The regulation 

provides that medians located in limited access freeway 

rights-of-way that exceed 5,000 square feet are subject 

to the provisions of Section 90 (Disturbed Open Areas) 

in lieu of Section 93. 

Preventative control measures for preventing the track 

out of mud and dirt from unpaved shoulders consist of 

the following minimum design standards for paved 

roads: 

• Constructing paved shoulders with a minimum 

width of four feet adjacent to the paved travel 

lane; or 

• (Proposed) Constructing paved road shoulders 

with a minimum width of eight feet adjacent to 

travel lanes on new roads with 3,000 ADT or 

greater; or 

• Applying and maintaining dust palliatives for a 

minimum width of four feet adjacent to the travel 

lane; or 

• Constructing curbing adjacent to the paved travel 

lane; or 

• Constructing paved median for paved roads. 

Preventative control measures for preventing the 

track out of mud and dirt from unpaved medians 

consist of the following minimum design standards 

for paved roads: 

• Construct medians with paving; or 

 

21 Watson, J.G., et. al., Effectiveness Demonstration of Fugitive 

Dust Control Methods for Public Unpaved Roads and Unpaved 

Shoulders of Paved Roads, DRI Document No. 685-5200.1F1, 

Desert Research Institute, Reno, Nevada, p 9-2 

Medians, Curbs 

Paved or Stabilized 

Preventative Control 

Measures for Unpaved 

Shoulders 

Preventative 

Control Measures 

for Unpaved 

Medians
 4-67 

• Apply and maintain dust palliatives; or 

• Construct curbing on the median adjacent to 

the traffic lane. 

Stabilization standards for dust palliative applications 

consist of the following: 

• Complying with a 20 percent opacity requirement; 

and

• Maintaining silt loading of no more than 0.33 

ounces per square foot. 

Test methods for determining compliance with the 

stabilization standards include an opacity test method 

and a silt content test method. 

Section 93 of the AQR sets standards that must be 

incorporated into any new or modified sections of paved 

roads during construction. In addition, the public 

agencies having jurisdiction over public roads in the 

nonattainment area have committed to developing a 

plan by February 15, 2002 for upgrading all existing 

roads to meet the requirements of Section 93 by 

December 31, 2006. Based on this commitment, it is 

assumed that all paved roads in the Las Vegas Valley 

will be in compliance with the Section 93 standards by 

2006. In the event a road is discovered that does not 

meet the requirements of Section 93 and is not included 

in an agency’s plan, then the road must be brought into 

compliance with the AQR Section 93 requirements 

within 365 days following the issuance of a corrective 

action order. If a road is included in an agency’s plan 

but is not scheduled for improvement in a timely fashion, 

AQD will work with the agency to reprioritize the road. 

Public works agencies will ensure the stabilization of the 

existing inventory of unpaved shoulders of paved road 

by the end of 2006. Plans will be developed through the 

following process. 

1. Each entity will identify the roadways that have a 

paved section less than 28’, which is the minimal 

acceptable width for two travel lanes and two fourfoot paved shoulders. 
 4-68 

2. Once the inventory is complete, the entities will then 

compare the inventory to their capital improvement 

program and developer agreements to determine 

which of the roadways will be brought up to the 

minimal acceptable width standard or full 

improvement standards over the next six years. 

3. For those roadways that are not to be improved over 

the next five years, a schedule will be developed for 

bringing them up to appropriate local standards by 

the end of 2006. The acceptable standard will be at 

a minimum either a 28’ or 32’ paved section. As part 

of the inventory effort, car counts on the roadways 

and silt loading measurements of the paved travel 

lane will be taken on all candidate roadways to 

determine their contribution to the inventory of PM10 

attributable to unstabilized shoulders. 

The SIP commitment to stabilize unpaved shoulders is 

described in Section 4.8.3.2. 

This regulation also mandates the purchase or leasing 

of certified PM10-efficient street sweepers for sweeping 

of paved roads or paved parking lots after 

January 1, 2001. This requirement applies to both 

public and private operators of street sweeping 

equipment. The regulation references South Coast Air 

Quality Management District (SCAQMD) Rule 1186 

certification requirements and the SCAQMD certified 

equipment list. The urban streets in Clark County are 

swept on the average of every two weeks. Rural streets 

are swept somewhat less frequently. Further details on 

street sweeping frequency are provided in Appendix J 

and Section 6.3.4.4. 

Clark County, the Nevada Department of 

Transportation, and the cities of Las Vegas, North Las 

Vegas, and Henderson currently operate a combined 

total of 72 street sweepers in the Las Vegas 

metropolitan area. When agencies reviewed their 

equipment inventories, it was found that most of the 

equipment already in use was in compliance with this 

regulation. Equipment lists are provided in Appendix J. 

Therefore, Clark County has not calculated emission 

reductions from this control measure for the attainment 

demonstration. 

Paved Road 

Unstabilized 

Shoulders Will Be 

Done by 2006

Certified PM-Efficient 

Street Sweepers To Be 

Used for Paved Areas
 4-69 

Clark County has developed an extensive flood control 

system to minimize property damage and the 

deposition of materials on roadways caused by storm 

events. As noted in Chapter 2, precipitation is limited in 

the Las Vegas Valley, averaging only 4.13 inches per 

year. However, annual rainfall can vary substantially 

from year to year and from rainfall event to rainfall 

event. In general, rainfall events are infrequent but may 

result in intense precipitation. As a result, the 

infrastructure for handling storm water is necessarily 

robust to the extent that minor storms do not generally 

result in significant off-site deposition of material. The 

flood control program for the area is directed by the 

Clark County Regional Flood Control District. The 

District was created in 1986 and was charged with the 

responsibility of developing and implementing a 

comprehensive flood control master plan to alleviate 

flooding in Clark County. Funding has been provided 

through voter-approved sales taxes and General 

Obligation Flood Control Bonds. Since 1987 the District 

has funded projects totaling over $600 million. 

Completed facilities include 45 detention basins and 

approximately 220 miles of channels, washes, and 

storm drains. Additionally, there are approximately 

$1.1 billion in flood control facilities identified for future 

funding. 

 

The natural-event action plans or policies in place in 

Clark County and the cities of North Las Vegas, Las 

Vegas, and Henderson to deal with cleanup when a 

major storm event does occur complement the work of 

the Flood Control District to reduce flood damage. The 

plans entail mobilization of all available equipment from 

unaffected areas to the event location(s) and removal of 

heavy silt deposits as quickly as possible. Since 

completion of the flood control system to handle a 100-

year storm is years out (pending additional $1.1 billion in 

funding), there is still the possibility of widespread 

erosion and deposition from a major storm. The entity 

plans require quick response and focus maximum 

resources on the rapid clean up of roadways. These 

programs are documented in Appendix J. 

4.5.2.4.4 Technical Feasibility and Environmental 

Impacts: Paved road shoulder and median 

requirements set forth in this regulation for public roads 
 4-70 

will be met in accordance with the standards in AQR 

Section 93. Public works agencies consider paving to 

be the most cost-effective solution to stabilization over 

an extended period rather than the use of dust 

suppressants or gravel. Dust suppressants and gravel 

will most likely be used by public works departments as 

a temporary measure. Some private operators of paved 

roads with low traffic volumes may elect to utilize dust 

suppressants to meet the requirements of this 

regulation. This control measure will therefore not 

significantly increase the use of dust suppressants. 

City and county paved road development standards in 

the Las Vegas Valley already comply with or exceed the 

design standards set forth in this regulation. Paved 

public roads are constructed to a lesser standard only 

when partial improvements are approved for a 

development project as an interim measure pending 

additional development in an area. Where road 

medians are to be incorporated into the final road 

design, they are almost always paved or curbed, even 

when partial improvements are authorized. 

The sweeper requirements set forth in this regulation 

have been implemented by the SCAQMD. Initially, 

public works agencies expressed concern that no 

exemptions were included in the regulation to allow for 

the purchase of broom-type sweepers. The agencies 

noted that broom sweepers are needed for cleanup of 

heavy debris deposits after flood events and for certain 

other task which vacuum-type sweepers cannot 

perform. A review of the updated SCAQMD-certified 

street sweeping equipment list indicated that broom 

sweepers, including models utilized by local agencies, 

are now certified as PM10-efficient, eliminating this 

concern. Therefore, it is now technically feasible for an 

agency’s entire sweeper fleet to be certified as PM10-

efficient. 

4.5.2.4.5 Emission Reductions: All emission reduction 

computations are based on the 2006 attainment year for 

the 24-hour NAAQS. Because a very large proportion 

of the existing fleet of publicly owned and operated 

street-sweeping equipment in Clark County complies 

with this regulation, no emission reductions have been 

taken that would 

Paving Most CostEffective Method for 

Stabilization of Dust 

Sweeper 

Requirements 
 4-71 

otherwise be achieved through the PM10-efficient 

sweeper requirements. The emission reductions from 

this control measure are reflected in the emission 

inventory baseline. This control measure also applies to 

private operators of sweeping equipment. The impact of 

this regulation on these privately owned sweeping fleets 

is not known, but is likely to be insignificant, and was not 

factored into this attainment demonstration. 

Entrained/re-entrained fugitive dust emissions from 

paved roads are dependent on silt loadings deposited 

on all classes of paved roads from all sources and 

Vehicle Miles Traveled (VMT) on these roads. 

Reductions in silt loadings do not result in linear 

percentage reductions of PM10 emissions. Because 

PM10 emissions generated from paved roads are 

dependent on both silt loadings and VMT for each 

roadway type, emission reductions must be computed 

separately by VMT and silt loading for each road class. 

These computations are detailed in Appendix B. 

Emission reductions that occur due to the reductions in 

silt loadings from these control measures must likewise 

be calculated separately by VMT and road type. 

Standard emission reductions, rule penetration, rule 

effectiveness, and overall reduction percentages 

therefore cannot be applied to these reductions in the 

standard form. Emission reduction calculations for 

entrained/re-entrained road dust are detailed in 

Appendix L. 

The controlled and uncontrolled entrained/re-entrained 

fugitive dust emission for paved roads from the 2006 

valley-wide 24-hour emission inventory taken from 

Chapter 5 are as follows: 

• Baseline Emissions: 161.70 TPD; 

• Controlled Emissions: 114.86 TPD; and 

• Emission Reductions: 46.84 TPD. 

These emission reductions include reductions from silt 

loading from all control measures except street 

sweeping, including reduced deposition from other 

sources, improving unstabilized shoulders, and reduced 

track out from construction activities. 

Sweeper Fleets Not 

Factored In 

Paved Road Dust 

Emissions Dependent 

on Silt Loading and 

VMT
 4-72 

Reduced deposition of particulate matter onto paved 

roads occurs from control measures applied to disturbed 

open areas, construction activities, and unpaved roads. 

This reduced deposition onto paved roads results in 

lower paved road silt loadings which in turn results in 

lower entrained/re-entrained PM10 emissions from the 

paved roads. The weighted composite of the emission 

reductions from disturbed open areas, construction 

activities, and unpaved roads is an approximate overall 

reduction of 75 percent. If the silt loading value is 

reduced by 75 percent in proportion to emission 

reductions from other sources, then factoring the 

reduced silt loading values into the paved roads 

emission equation would yield an approximate reduction 

of 60 percent in paved road emissions. However, a 

linear relationship between local fugitive dust source 

emissions and silt loading has not been established. 

Clark County has therefore estimated the reductions 

from roadway silt loadings gained from the reduced 

fugitive emissions from other sources to be 30 percent. 

This estimate is based on the professional judgment of 

the CCDCP air planning staff observing local conditions 

and is documented in Appendix L. Staff believes that 

the actual reductions are likely to be greater, but that 

this conservative estimate is warranted due to the lack 

of empirical data. The total PM10 emission reductions 

from paved roads that are gained from reduced 

emissions from open areas, construction activities, and 

unpaved roads are detailed in Appendix L, Table L-15 

and summarized below: 

• Baseline Emissions: 122.58 TPD; 

• Controlled Emissions: 97.92 TPD; and 

• Emission Reductions: 24.66 TPD. 

Note that these reductions do not include reductions 

from improving unpaved shoulders or reducing track out 

from construction activities. 

Four roadway categories in Clark County contain road 

segments without improved shoulders. Based on the 

Dames & Moore Silt Loading Measurements study,22 it 

was determined that the silt loadings for roadways 

 

22 Dames & Moore, Silt Loading Measurements for Clark County 

Paved Roads, document 44429-001-131, prepared for the Clark 

County Regional Transportation Commission, March 16, 2000 

Reduced PM10

Emissions from Paved 

Road Dust Not 

Linearly Related to Silt 

Loading Reduction
 4-73 

without improved shoulders are 1.34 g/m2 for major and 

minor arterials and 24.7 g/m2

 for collectors and local 

roadways. The respective silt loadings from Table B-15 

for these roadways with improved shoulders are 1.04 

g/m2

 for minor arterials, 0.49 g/m2 for major arterials, 

0.86 g/m3 for collectors, and 1.70 g/m3

 for local streets. 

As paved road shoulders are improved and silt loadings 

decline, it is necessary to reapportion VMT from the 

higher silt loading values to the lower silt loading values 

in computing emissions. Section 93 rule effectiveness 

and rule penetration were estimated at 95 percent for 

the improvement of existing unpaved shoulders. 

Therefore, 90 percent of roadways that currently do not 

have improved shoulders would have improved 

shoulders in 2006. The total paved road dust emissions 

from this category would therefore be calculated with 90 

percent of the daily VMT traveling on roadways with 

improvements and ten percent traveling on roadways 

without improved shoulders. These emissions are 

detailed in Appendix L, Table L-16, and summarized 

below: 

• Uncontrolled Emissions 

 -No Shoulders Improved: 37.96 TPD; 

• Potentially Controlled Emissions 

 -All Shoulders Improved: 13.63 TPD; 

• Actual Controlled Emissions 

 -90 percent of Shoulders Improved: 16.04 TPD; 

 and 

• Emission Reductions: 21.92 TPD. 

Actual controlled emissions are calculated from the 

uncontrolled emissions and potentially controlled 

emissions as follows: 

Total Emissions = 0.9(13.63 tons) + 0.1(37.96 tons) 

= 16.04 (tons per day). 

4.5.2.4.6 Control Measure Cost: The cost of 

compliance with this control measure will vary 

depending on the control measure approach utilized, but 

is estimated as follows: 

• Cost Per Mile Per Year Using Paving:

 $2,500 to $25,000;

 
 4-74 

• Cost Per Mile Per Day Using Paving: 

$6.85 to $68.49; 

• Cost Per Mile Per Year Using Dust Palliatives: 

 $1,100 to $3,200; 

• Cost Per Mile Per Day Using Dust Palliatives: 

 $3.01 to $8.77; 

• Miles of Shoulder Improvements: 

 444 miles. 

Low end and high end costs of compliance are 

estimated by multiplying the estimated cost of shoulder 

improvements by the number of miles of shoulder 

improvements required. These shoulder improvements 

will be constructed under public works improvement 

plans and the cost of enforcement is expected to be 

minor. Enforcement cost has therefore not been 

included in the total cost for implementation of this 

control measure. 

Low High 

Total Cost per Day $1,336.44 $30,409.56 

Emission 

Reductions 21.92 TPD 21.92 TPD 

Cost 

Effectiveness $61 per ton $1,387 per ton 

The Clark County Health District Board of Health has 

adopted Section 93 and Section 94 of the AQR as 

RACM and BACM for this emission source category. 

4.5.2.5 Control Measures For Unpaved Road Dust 

(24-hour Standard)

4.5.2.5.1 Sources Controlled: All publicly and privately 

owned unpaved roads, including unpaved alleys, 

unpaved easement roads, and unpaved access roads. 

4.5.2.5.2 Implementation Schedule: The 

requirements of this regulation became effective on 

June 22, 2000 for the construction of new publicly 

owned and maintained and privately owned unpaved 

roads. Owners and/or operators of existing unpaved 

roads having vehicular traffic of 150 vehicle trips or

more per day are required to apply control measures

Paved Road Control 

Costs 

 

 
 4-75 

to one-third of the total road miles by June 1, 2001; 

apply control measures to two-thirds of the total road 

miles by June 1, 2002; and apply control measures to all 

unpaved roads having vehicular traffic of 150 vehicle 

miles or more per day by June 1, 2003.

4.5.2.5.3 Description of Control Strategy: This 

regulation requires the implementation of controls for 

preventing fugitive dust emissions for unpaved roads. 

Control measures applicable to unpaved roads consist 

of the following: 

• Paving; or 

• Applying and maintaining dust palliatives; or 

• Applying and maintaining alternative controls 

approved by U. S. EPA. 

In addition, the regulation does not allow the 

construction of unpaved roads in public thoroughfares 

after June 22, 2000, unless the unpaved road is an 

interim component of an active paving project. 

Stabilization standards include the following: 

• Compliance with a 20 percent opacity 

requirement; and

• Maintenance of a silt loading of no more than 

0.33 ounces per square foot; or 

• Maintenance of silt content of no greater than 6 

percent. 

Test methods for determining compliance with the 

control measures and stabilization standards include an 

opacity test method and a silt content test method. 

It is estimated that approximately 64 miles of the 259-

mile total base year inventory of publicly owned and 

maintained unpaved roads have 150 or more trips per 

day. However, this estimate is based on current traffic 

counts and the actual vehicle travel may be subject to 

seasonal variation. In order to comply with this 

regulatory program, Clark County and the cities of Las 

Vegas, North Las Vegas, and Henderson have 

obligated Congestion Mitigation and Air Quality 

Improvement Program (CMAQ) funds (including local 

match) over the next three years to pave publicly 

 Unpaved Road 

Control Measures 

 

Entities Have 

Obligated CMAQ 

Funds To Pave 

Publicly Owned 

Unpaved Roads
 4-76 

owned unpaved roads. The entities settled upon paving 

as the most cost-effective method of addressing the 

PM10 emissions resulting from the publicly owned and 

maintained roadways. Even though this is the most 

expensive alternative, it has the lowest maintenance 

cost, and will provide for longer life facilities. This 

funding commitment will ensure the public agencies can 

comply with the regulation. 

It is the intention of the respective public agencies to 

pave all roads with average vehicle trips of 150 or more 

per day. As part of either the development of the bid 

package, or as part of the construction agreement, 24-

hour car counts will be obtained on each segment to be 

paved. During construction, silt-loading tests will be 

obtained for each segment. Each entity is in the 

process of determining the ownership of the unpaved 

roadways. As these are determined, they will be placed 

in the database described below, and these will become 

the basis of the bid packages. 

Clark County is in the process of preparing an extranet 

website that will contain information on the roads that 

have been designated as publicly owned and 

maintained which local governments will be paving. The 

inventory of unpaved roads was developed by the 

respective public works departments after extensive 

review of the existing roadway network. Information on 

the website will be available to all governmental 

agencies at the local, regional, state, and federal level. 

The SIP commitment for unpaved roads is described in 

Section 4.8.3. 

The miles of privately owned unpaved roads have not 

been inventoried in detail, but public works staff from 

Clark County and the cities of Las Vegas, North Las 

Vegas, and Henderson have found a total of 45 miles of 

privately owned unpaved roads in the nonattainment 

area. Of these, 40.5 miles are located in the BLM 

Disposal Boundary area. None of these privately owned 

unpaved roads had traffic volumes greater than 50 ADT. 

As set forth under the commitments section of this 

chapter, Clark County is committing to develop an 

improved inventory of these privately owned unpaved 

roads. 

Inventory of Privately 

Owned Unpaved 

Roads Show None 

with Greater than 50 

VMT 
 4-77 

4.5.2.5.4 Technical Feasibility and Environmental 

Impacts: The control measures and stabilization 

criteria required under this regulation have been 

implemented in Maricopa County, Arizona except that 

the Maricopa County regulation allows the use of gravel 

as a control measure. Although gravel is listed as a 

control measure for unpaved roads in the Fugitive Dust 

Technical Information Document,23 experience in Clark 

County has shown that this control measure is not 

effective in the Las Vegas Valley. Both Clark County 

and Maricopa County use similar activity thresholds for 

unpaved roads, except that the Maricopa Rule only 

applies to publicly owned unpaved roads. Both areas 

also have programs in place that will result in the paving 

of some unpaved roads with less than 150 ADT. 

A concern of public works agencies during the 

development of this program was that if the time frame 

for implementing this control measure was shortened to 

one or two years, then funding would not be available to 

implement the program. Costs could also escalate 

significantly, making acquisition of sufficient funding 

even more difficult. Costs would be expected to 

increase significantly under an accelerated program 

because of the limited number of contractors in the 

region performing this class of work. The time lines and 

requirements of the adopted regulatory program are not 

expected to significantly inflate road paving costs. 

Because public agencies are planning to comply with 

the provisions of this regulation by paving, this 

regulation is not expected to significantly increase the 

use of dust suppressant products. Incidental drainage 

improvements constructed with the road improvements 

mandated under this regulation will help to address silt 

loading on paved roads and storm water runoff issues. 

4.5.2.5.5 Emission Reductions: The rule applies to 

the PM10 emission source category “unpaved road dust” 

with a total of 55.11 TPD of PM10 emissions coming 

 

23 Fugitive Dust Background Document and Technical Information 

Document for Best Available Control Measures, EPA-450/2-92-004; 

U. S. Environmental Protection Agency; Research Triangle Park, 

1992; pp 3-15, 3-16 

Gravel Not Effective in 

Clark County 

Cost Issues 

 

 
 4-78 

from 259 miles of unpaved roads in 2006. However, 66 

percent of these emissions come from 64 miles of 

unpaved roads having vehicle travel of 150 or more trips 

per day. This source category contributes approximately 

13.95 percent of the total valley-wide PM10 emissions. 

Paving as a control measure is calculated to provide a 

99 percent emission reduction. The rule penetration for 

this control measure, based on the 150 or more vehicle 

trips per day action threshold, is: 

• Rule Penetration-2001 (1/3 of all roads paved):

 22 percent; 

• Rule Penetration-2002 (2/3 of all roads paved): 

44 percent; and 

• Rule Penetration-2003 (all roads paved):

 66 percent. 

This regulation will primarily apply to public agencies. 

None of the privately owned unpaved roads currently 

inventoried meet the 150 ADT threshold. Public works 

agencies are developing a compliance program that is 

subject to public review and that will allow government 

agencies to track program progress through the 

extranet. Progress reports must also be submitted to 

the AQD on an annual basis. The rule effectiveness of 

this measure is projected to be 99 percent, due to the 

strength of the commitment, its financial backing, and 

the priority the agencies are giving to compliance. The 

overall control reduction for this source category is 65 

percent. 

Emission reductions from the 2006 24-hour inventory 

are shown below: 

• Baseline Emissions: 55.11 TPD; 

• Controlled Emissions: 19.50 TPD; and 

• Emission Reductions: 35.61 TPD. 

 

4.5.2.5.6 Control Measure Costs: The following 

control measure cost and assumptions were utilized in 

developing cost effectiveness estimates: 

• Paving Cost24 - Per mile per year $50,000; 

 

24 Per year cost calculated assuming a five-year life span for paved 

roads. 

Unpaved Roads 

Emission Reductions 
 4-79 

• Paving Cost25 - Per mile per day: $137; 

• Annual Cost of Enforcement: $25,740; and 

• Daily Cost of Enforcement: $70. 

The number of miles of unpaved roads that are subject 

to this control measure is estimated to be 64 miles in the 

valley-wide emission inventory. Applying the control 

cost of $137 per day to this road mileage results in total 

paving cost of $8,768 per day. 

The public cost of enforcement must be included when 

calculating control measure cost effectiveness. As 

noted in the discussion of commitments for additional 

AQD enforcement staffing levels in this chapter, the total 

cost of this expanded effort for Sections 90 through 94, 

excluding certain administrative costs, is $780,000.26 

Adjusting for administrative cost, it is estimated that the 

total enforcement cost attributed to this regulation will be 

$25,740.27 Dividing this amount by 365 yields the daily 

cost of enforcement ($70 per day). Adding the cost per 

day of paving and cost per day of enforcement yields 

the total cost per day of implementing this control 

measure. 

Dividing the total cost per day of control measure 

implementation by the emission reductions achieved per 

day by the control measure yields the cost effectiveness 

for this control measure. 

Paving 

Total Cost per Day $8,838 

Emission Reductions 35.61 TPD 

Cost Effectiveness $248 per ton 

Although this cost effectiveness value is favorable, 

several issues make acceleration or expansion of this 

 

25 Per day cost calculated by dividing per year cost by 365. 26 Naylor, M.H., Workplan for PM10 Resources Commitment, 

Prepared for Clark County Health District Board of Health, July 11, 

2000. 

27 The estimated cost for enforcing Section 91 is based on the 

assumption that 3 percent of the new enforcement cost will be 

allocated to Section 91. Unaccounted administrative costs are 

estimated to be 10 percent of the operational cost. Therefore, 

Section 91 enforcement costs are calculated as follows: 

$780,000x0.03x1.10=$25,740. 

Unpaved Roads 

Control Costs 
 4-80 

program infeasible. These costs are predicated on the 

use of all CMAQ funding not allocated to other 

proposals in the Las Vegas Valley over the next three 

years, and do not include interest costs that would be 

incurred if the program were expanded beyond what 

can be financed with CMAQ funding. 

The Clark County Health District Board of Health has 

adopted Section 91 of the Air Quality Regulations as 

RACM and BACM for this source category. 

4.5.2.6 Control Measures For Race Tracks (24-Hour 

Standard)

4.5.2.6.1 Sources Controlled: Dirt race tracks on 

publicly and privately owned disturbed open areas and 

vacant lots. 

4.5.2.6.2 Implementation Schedule: All requirements 

become effective on January 1, 2001. 

4.5.2.6.3 Description of Control Strategy: This 

control measure is implemented through Section 90 of 

the Air Quality Regulations. This regulation requires the 

implementation of controls for preventing fugitive dust 

emissions from disturbed open areas and vacant lots 

with a cumulative disturbed area larger than 5,000 

square feet. Although the regulation does not 

specifically prohibit dirt race tracks per se, it is not 

possible to allow operation of off-road vehicles, 

including “dirt bikes” and “all terrain vehicles” (ATVs) on 

open areas and vacant lots and remain in compliance 

with the regulation. 

Where motor vehicle trespass is occurring on open 

areas and vacant lots greater than 5,000 square feet, 

regardless of the amount of cumulative disturbed 

surface area, owners must take steps to prevent 

trespass and stabilize the surface. Where greater than 

5,000 square feet of cumulatively disturbed surface 

exists, if owners have not implemented the latter control, 

they must apply dust palliative (not just water) or gravel. 

Control measures applicable to disturbed areas consist 

of the following: 

Expansion of this 

Program Is 

Infeasible Beyond 

Current 

Commitment 

Dirt Race Track 

Control Measures 

 

 
 4-81 

• Preventing motor vehicle access, including dirt 

bike and all terrain vehicle access, and stabilizing 

the disturbed surfaces; or 

• Applying dust palliatives to disturbed surfaces; or 

• Applying and maintaining a uniform surface 

gravel cover over the disturbed surfaces; or 

• Applying and maintaining alternative control 

approved by U. S. EPA. 

Test methods for determining compliance with the 

regulation’s stabilization requirements consist of the 

following: 

• Drop ball test; or 

• Threshold friction velocity test; or 

• Rock test method for non-erodible surface 

elements. 

4.5.2.6.4 Technical Feasibility and Environmental 

Impacts: Much of the discussion under Technical 

Feasibility and Environmental Impacts in the Control 

Measures For Unpaved Parking Lots (24-Hour 

Standard) section is also applicable to this control 

measure. As noted in that discussion, the controls of 

choice under this regulation will generally be vehicular 

access controls and the application of dust 

suppressants. Application of dust suppressants will not 

be economical if off-road vehicle use is allowed to 

occur. To the extent that ATV use is presently occurring 

in the Las Vegas Valley urban area, their use will be 

sharply curtailed due to the associated economic cost of 

these activities under this regulation. Where property 

owners find that their property is impacted by ATV use, 

access restrictions will be the preferred control measure 

of choice. 

4.5.2.6.5 Emission Reductions: “Race tracks” were 

found to have significant impacts at the Craig Road and 

Green Valley micro-inventory sites. These activities 

occurred where ATV users identified a vacant parcel 

that was unfenced and unposted and placed some old 

tires on the site to form a “race track.” The emission 

reduction, rule penetration, rule effectiveness, and 

overall reduction for this control measure are detailed in 

Appendix L and are shown below: 

Access Controls 

Preferred Control 

Measure 
 4-82 

 Race Track Wind Erosion 

• Emission Reduction 91percent; 

• Rule Penetration 99percent; 

• Rule Effectiveness 80 percent; 

• Overall Control Reduction 72 percent; 

Race Track Vehicles 

• Emission Reduction 100 percent; 

• Rule Penetration 99 percent; 

• Rule Effectiveness 80 percent; and 

• Overall Control Reduction 79 percent. 

Applying these overall control reductions to the 2006 

uncontrolled emissions for this source category yields 

the following emission reductions: 

RACE 

TRACKS 

Uncontrolled 

Emissions 

Tons/Day

Controlled 

Emissions 

Tons/Day 

Emission 

Reductions 

Tons/Day 

CRAIG ROAD

Wind Erosion 1.71 0.48 1.23 

Emissions 0.72 0.15 0.57 

GREEN VALLEY

Wind Erosion 1.08 0.30 0.78 

Emissions 0.18 0.04 0.14 

Off-road racing is sufficiently miniscule in scale as to not 

warrant a separate category in the valley-wide 

inventories. To the extent that “dirt bike” and “all terrain 

vehicle” use disturbs open areas and vacant parcels in 

the urban area, they are accounted for in the disturbed 

vacant land inventories. Developing a separate 

inventory for this source category is very difficult due 

to the sporadic nature of this activity, most of which 

occurs on property without the property owner’s 

permission.28

 

28 Testimony and complaints about unauthorized off-road vehicle 

use were heard at a number of the workshops on disturbed vacant 

land and unpaved road rules. In addition, when surveying countyowned land for surface stabilization, County staff observed “dirt 

bike” and “all terrain vehicle” use occurring in areas where this 

activity was clearly not authorized. 

Recreational Vehicle 

Use Is Sporadic and of 

Limited Scale 

 
 4-83 

In reviewing BLM permits for off-road racing events on 

BLM land, it was found that no off-road racing events 

were approved by BLM in the nonattainment area during 

the past year. Currently BLM is working to establish offroad racing courses outside the nonattainment area. 

Courses within the nonattainment area are permanently 

closed. 

4.5.2.6.6 Control Measure Costs: The control 

measure cost discussion in the Control Measures For 

Disturbed Vacant Lands (24-Hour Standard) section is 

also applicable to this control measure. 

4.5.3 Adopted Control Measures For The Annual 

NAAQS 

Table 4-15 (pages 4-83 – 4-88) provides a detailed list 

of the specific elements of the Clark County control 

measures adopted or implemented to achieve 

attainment of the annual PM10 NAAQS. 

4.5.3.1 Control Measures For Disturbed Vacant 

Lands (Annual Standard)

4.5.3.1.1Sources Controlled: 1) Publicly and privately 

owned disturbed open areas and vacant lots. 2) Weed 

abatement by discing and blading of open areas and 

vacant lots. 

4.5.3.1.2 Implementation Schedule: All requirements 

became effective on January 1, 2001. 

4.5.3.1.3 Description of Control Strategy: See 

Description Of Control Strategy discussion in Control 

Measures For Disturbed Vacant Lands (24-Hour 

Standard) Section 4.5.2.1.2. 

4.5.3.1.4 Technical Feasibility and Environmental 

Impacts: See Technical Feasibility and Environmental 

Impacts discussion in Control Measures For Disturbed 

Vacant Lands (24-Hour Standard) Section 4.5.2.1.3. 

Disturbed Vacant 

Lands Control 

Measures 
 4-84 

Table 4-15 

Significant PM10 Sources Control Measures-Annual Standard 

Source 

Category BACM Control Measures 

Overall 

Reduction 

Percentage 

with Control 

Measures 

Area Sources 

Disturbed 

Vacant 

Lands 

• Prevent Motor Vehicle Access and Stabilize Disturbed 

Surface {Section 90.2.1.1(a)} 

• Stabilize Disturbed Surface greater than 5,000 sq.ft. with 

Gravel or Dust Palliatives {Section 90.2.1.1(b)} 

• Discing or Blading areas of 5,000 square feet or larger for 

weed abatement, apply water both before and during 

operations {Section 90.2.2.1(a),(b)} 

• After Discing or Blading occurs, stabilize disturbed surfaces 

with Gravel, Water, Dust Palliatives, or Paving {Section 

90.2.2.1(c)} 

36% (2001) 

72% (2002 +) 

Unpaved 

Parking Lots 

• Pave {Section 92.2.1.2(a)} 

• Apply and Maintain Dust Palliatives {Section 92.2.1.2(b)} 

• Apply and Maintain Dust Palliatives on Traffic Lanes and 

apply surface gravel to depth of two inches on Parking 

Areas {Section 92.2.1.2(c)} 

• (Proposed) Prohibition of new unpaved parking lots 

• (Proposed) Prohibition of dust crossing property line 

Wind Erosion 

36% (2001) 

72% (2002+) 

Vehicles 

24% (2001) 

48% (2006) 

Construction 

Activity 

Fugitive 

Dust

• Apply Dust Suppressant (water) throughout construction site 

to stabilize soil (Section 94 Handbook, CST 10-l) 

• Apply Dust Palliative on soils based on soil type (Section 94 

Handbook, CST 12) 

• Traffic Control in Construction Area (Section 94 Handbook, 

CST 10-2, CST 20-1, CST 19 Requirements & CST19-7) 

• Use tarps or other suitable enclosures on haul truck (Section 

94 Handbook, CST 13-1) 

• Stabilize surface with materials that will prevent track out of 

mud and dirt to the Paved section, with wheel shakers, 

wheel washers {Section 94 Handbook, CST 19-3, 19-4 and 

Section 94.6.8.(c)} 

• Permits Required for Construction Activities (Section 94.4.1) 

• Public Information Signage Required (Section 94.4.5) 

• Site-Specific Dust Mitigation Plan Required for Projects of 

ten acres or greater in size (Section 94.4.9) 

• Dust Control Monitor Required for Construction Activity 

having 50 acres or more of actively Disturbed Soil (Section 

94.4.11) 

34% (2001) 

68% (2003+) 
 4-85 

Source 

Category BACM-Control Measures

Overall 

Reduction 

Percentage 

with Control 

Measures

Construction 

Activity 

Fugitive 

Dust 

(continued)

• 20% Opacity Limit on Dust Emissions {Section 94.5.2 & 

94.6.8(d)} 

• 100-yard Plume Limit {Section 94.6.8(b)} 

• (Proposed) 100-foot plume limit 

• (Proposed) Prohibition of dust crossing property line 

• Controls Required on site at all times, whether or not 

Construction Activity is occurring (Section 94.5.3) 

• Backfilling (Section 94 Handbook, CST 1) 

• Blasting – Abrasive (Section 94 Handbook, CST 2) 

• Blasting – Soil and Rock (Section 94 Handbook, CST 3) 

• Clearing and Grubbing (Section 94 Handbook, CST 4) 

• Clearing Forms (Section 94 Handbook, CST 5) 

• Crushing (Section 94 Handbook, CST 6) 

• Cut and Fill (Section 94 Handbook, CST 7) 

• Demolitions – Implosion (Section 94 Handbook, CST 8) 

• Demolitions – Mechanical/Manual (Section 94 Handbook, 

CST 9) 

• Disturbed Land Large Tracts (Section 94 Handbook, CST 

11) 

• Dust Suppressant, Dust Palliative, and Surfactant Selection 

and Use (Section 94 Handbook, CST 12) 

• Landscaping (Section 94 Handbook, CST 14) 

• Paving/Subgrade Preparation (Section 94 Handbook, CST 

15) 

• Screening (Section 94 Handbook, CST 16) 

• Staging Areas (Section 94 Handbook, CST 17) 

• Stockpiles (Section 94 Handbook, CST 18) 

• Traffic – Construction Related (Section 94 Handbook, CST 

20) 

• Trenching (Section 94 Handbook, CST 21) 

• Truck Loading (Section 94 Handbook, CST 22) 

• (Proposed) Prohibition on use of dry rotary brushes or 

blower devices to clean up track out

Table 4-15 

Significant PM10 Sources Control Measures-Annual Standard 

(continued) 
 4-86 

Source 

Category BACM-Control Measures 

Overall 

Reduction 

Percentage 

with Control 

Measures

Windblown 

Construction 

Dust 

• Apply Dust Suppressant (water) throughout construction site 

to stabilize soil (Section 94 Handbook, CST 10-l) 

• Apply Dust Palliative on soils based on soil type (Section 94 

Handbook, CST 12) 

• Traffic Control in Construction Area (Section 94 Handbook, 

CST 10-2, CST 20-1, CST 19 Requirements & CST19-7) 

• Use tarps or other suitable enclosures on haul truck (Section 

94 Handbook, CST 13-1) 

• Stabilize surface with materials that will prevent track out of 

mud and dirt to the Paved section, with wheel shakers, wheel 

washers {Section 94 Handbook, CST 19-3, 19-4 and Section 

94.6.8.(c)} 

• Permits Required for Construction Activities (Section 94.4.1) 

• Public Information Signage Required (Section 94.4.5) 

• Site Specific Dust Mitigation Plan Required for Projects of ten 

acres or greater in size (Section 94.4.9) 

• Dust Control Monitor Required for Construction Activity having 

50 acres or more of actively Disturbed Soil (Section 94.4.11) 

• 20% Opacity Limit on Dust Emissions {Section 94.5.2 & 

94.6.8(d)} 

• 100 yard Plume Limit {Section 94.6.8(b)} 

• Controls Required on site at all times, whether or not 

Construction Activity is occurring (Section 94.5.3) 

• Backfilling (Section 94 Handbook, CST 1) 

• Blasting – Abrasive (Section 94 Handbook, CST 2) 

• Blasting – Soil and Rock (Section 94 Handbook, CST 3) 

• Clearing and Grubbing (Section 94 Handbook, CST 4) 

• Clearing Forms (Section 94 Handbook, CST 5) 

• Crushing (Section 94 Handbook, CST 6) 

• Cut and Fill (Section 94 Handbook, CST 7) 

• Demolitions – Implosion (Section 94 Handbook, CST 8) 

• Demolitions – Mechanical/Manual (Section 94 Handbook, CST 

9) 

• Disturbed Land Large Tracts (Section 94 Handbook, CST 11) 

• Dust Suppressant, Dust Palliative, and Surfactant Selection 

and Use (Section 94 Handbook, CST 12) 

• Landscaping (Section 94 Handbook, CST 14) 

• Paving/Subgrade Preparation (Section 94 Handbook, CST 15) 

• Screening (Section 94 Handbook, CST 16) 

• Staging Areas (Section 94 Handbook, CST 17) 

36% (2001) 

71% (2002+) 

Table 4-15 

Significant PM10 Sources Control Measures-Annual Standard 

(continued)
 4-87 

Source 

Category BACM Control Measures 

Overall 

Reduction 

Percentage 

with Control 

Measures

Windblown 

Construction 

Dust 

(continued) 

• Stockpiles (Section 94 Handbook, CST 18) 

• Traffic – Construction Related (Section 94 Handbook, CST 20) 

• Trenching (Section 94 Handbook, CST 21) 

• Truck Loading (Section 94 Handbook, CST 22) 

On-Road Mobile Sources 

Paved Road 

Dust 

(includes 

Construction 

Track Out) 

• Pave or Stabilize four feet of Shoulders (Section 93.2.1.1) 

• (Proposed) Stabilize eight feet of shoulders on new roads 

with 3,000 ADT or greater 

• Pave or Stabilize Medians with solid paving across median 

(Section 93.2.1.4) 

• Use PM-Efficient Street Sweepers (Section 93.2.3.1) 

• Prevent mud and dirt track out with wheel shakers, or wheel 

washers must be employed at Construction Sites to prevent 

mud and dirt track out onto paved roads (Section 94 

Handbook, CST 19-3 & CST 19-4) 

• Clean up mud and dirt track out once every 24 hours and 

when track out extends more than 50 feet 

N/A 29 

Unpaved 

Road Dust 

• Pave Unpaved Roads With Traffic ≥ 150 ADT 

{Section 91.2.1.3(a)}; or

• Apply and Maintain Dust Palliatives to Unpaved Roads With 

Traffic ≥ 150 ADT {Section 91.2.1.3(b)} 

Paving PhaseIn 

(2001) – 22% 

(2002) – 44% 

(2003+) – 65% 

Highway 

Construction 

Project 

Activities 

• Apply Dust Suppressant (water) throughout construction site 

to stabilize soil (Section 94 Handbook, CST 10-l) 

• Apply Dust Palliative on soils based on soil type (Section 94 

Handbook, CST 12) 

• Traffic Control in Construction Area (Section 94 Handbook, 

CST 10-2, CST 20-1, CST 19 Requirements & CST19-7) 

• Use tarps or other suitable enclosures on haul truck (Section 

94 Handbook, CST 13-1) 

• Stabilize surface with materials that will prevent track out of 

mud and dirt to the Paved section, with wheel shakers, wheel 

washers {Section 94 Handbook, CST 19-3, 19-4 and Section 

94.6.8.(c)} 

• Permits Required for Construction Activities (Section 94.4.1) 

• Public Information Signage Required (Section 94.4.5) 

• Site-Specific Dust Mitigation Plan Required for Projects of ten 

acres or greater in size (Section 94.4.9)

34% (2001) 

63% (2003 +) 

 

29 No emission reductions taken for PM-Efficient Street Sweepers. Because there is not a linear relationship between silt loading and emission 

rates, the actual emission reductions will vary with the roadway mix in each inventory area. 

Table 4-15 

Significant PM10 Sources Control Measures-Annual Standard 

(continued)
 4-88 

Source 

Category BACM-Control Measures 

Overall 

Reduction 

Percentage 

with Control 

Measures

Highway 

Construction 

Project 

Activities 

(continued) 

• Dust Control Monitor Required for Construction Activity 

having 50 acres or more of actively Disturbed Soil (Section 

94.4.11) 

• 20% Opacity Limit on Dust Emissions {Section 94.5.2 & 

94.6.8(d)} 

• 100 yard Plume Limit {Section 94.6.8(b)} 

• (Proposed) 100-foot plume limit 

• (Proposed) Prohibition of dust crossing property line 

• Controls Required on site at all times, whether or not 

Construction Activity is occurring (Section 94.5.3) 

• Backfilling (Section 94 Handbook, CST 1) 

• Blasting – Abrasive (Section 94 Handbook, CST 2) 

• Blasting – Soil and Rock (Section 94 Handbook, CST 3) 

• Clearing and Grubbing (Section 94 Handbook, CST 4) 

• Clearing Forms (Section 94 Handbook, CST 5) 

• Crushing (Section 94 Handbook, CST 6) 

• Cut and Fill (Section 94 Handbook, CST 7) 

• Demolitions – Implosion (Section 94 Handbook, CST 8) 

• Demolitions – Mechanical/Manual (Section 94 Handbook, 

CST 9) 

• Disturbed Land Large Tracts (Section 94 Handbook, CST 11) 

• Dust Suppressant, Dust Palliative, and Surfactant Selection 

and Use (Section 94 Handbook, CST 12) 

• Landscaping (Section 94 Handbook, CST 14) 

• Paving/Subgrade Preparation (Section 94 Handbook, CST 

15) 

• Screening (Section 94 Handbook, CST 16) 

• Staging Areas (Section 94 Handbook, CST 17) 

• Stockpiles (Section 94 Handbook, CST 18) 

• Traffic – Construction Related (Section 94 Handbook, CST 

20) 

• Trenching (Section 94 Handbook, CST 21) 

• Truck Loading (Section 94 Handbook, CST 22) 

• (Proposed) Prohibition on use of dry rotary brushes or blower 

devices for clean up of track out 

• (Proposed) Acquire only vacuum type chip seal equipment 

Highway 

Construction 

Project-Wind 

Erosion 

• Apply Dust Suppressant (water) throughout construction site 

to stabilize soil (Section 94 Handbook, CST 10-l) 

• Apply Dust Palliative on soils based on soil type (Section 94 

Handbook, CST 12) 

36% (2001) 

71% (2002 +) 

Table 4-15 

Significant PM10 Sources Control Measures-Annual Standard 

(continued)
 4-89 

Table 4-15 

Significant PM10 Sources Control Measures-Annual Standard 

(continued) 

Source 

Category BACM-Control Measures

Overall 

Reduction 

Percentage 

with Control 

Measures 

Highway 

Construction 

Project-Wind 

Erosion 

(continued) 

• Traffic Control in Construction Area (Section 94 Handbook, 

CST 10-2, CST 20-1, CST 19 Requirements & CST19-7) 

• Use tarps or other suitable enclosures on haul truck (Section 

94 Handbook, CST 13-1) 

• Stabilize surface with materials that will prevent track out of 

mud and dirt to the Paved section, with wheel shakers, wheel 

washers {Section 94 Handbook, CST 19-3, 19-4 and Section 

94.6.8.(c)} 

• Permits Required for Construction Activities (Section 94.4.1) 

• Public Information Signage Required (Section 94.4.5) 

• Site-Specific Dust Mitigation Plan Required for Projects of ten 

acres or greater in size (Section 94.4.9) 

• Dust Control Monitor Required for Construction Activity 

having 50 acres or more of actively Disturbed Soil (Section 

94.4.11) 

• 20% Opacity Limit on Dust Emissions {Section 94.5.2 & 

94.6.8(d)} 

• 100 yard Plume Limit {Section 94.6.8(b)} 

• Controls Required on site at all times, whether or not 

Construction Activity is occurring (Section 94.5.3) 

• Backfilling (Section 94 Handbook, CST 1) 

• Blasting – Abrasive (Section 94 Handbook, CST 2) 

• Blasting – Soil and Rock (Section 94 Handbook, CST 3) 

• Clearing and Grubbing (Section 94 Handbook, CST 4) 

• Clearing Forms (Section 94 Handbook, CST 5) 

• Crushing (Section 94 Handbook, CST 6) 

• Cut and Fill (Section 94 Handbook, CST 7) 

• Demolitions – Implosion (Section 94 Handbook, CST 8) 

• Demolitions – Mechanical/Manual (Section 94 Handbook, 

CST 9) 

• Disturbed Land Large Tracts (Section 94 Handbook, CST 11) 

• Dust Suppressant, Dust Palliative, and Surfactant Selection 

and Use (Section 94 Handbook, CST 12) 

• Landscaping (Section 94 Handbook, CST 14) 

• Paving/Subgrade Preparation (Section 94 Handbook, CST 

15) 

• Screening (Section 94 Handbook, CST 16) 

• Staging Areas (Section 94 Handbook, CST 17) 
 4-90 

Table 4-15 

Significant PM10 Sources Control Measures-Annual Standard 

(continued) 

Source 

Category BACM-Control Measures

Overall 

Reduction 

Percentage 

with Control 

Measures 

Highway 

Construction 

Project-Wind 

Erosion 

(continued) 

• Stockpiles (Section 94 Handbook, CST 18) 

• Traffic – Construction Related (Section 94 Handbook, CST 

20) 

• Trenching (Section 94 Handbook, CST 21) 

• Truck Loading (Section 94 Handbook, CST 22) 

4.5.3.1.5 Emission Reductions: All emission reduction 

computations are based on the 2001 attainment year for 

the annual NAAQS. The control 

measure applies to the PM10 emission source category 

“Disturbed Vacant Lands/Unpaved Parking Lots” with a 

total of 48,500 TPY of uncontrolled PM10 emissions 

coming from 2,430 acres of disturbed vacant land. 

Control measures and emission reductions for unpaved 

parking lots are addressed under the unpaved parking 

lots section. The emission reduction, rule penetration, 

rule effectiveness, and overall reduction for this control 

measure are detailed in Appendix L and are shown 

below: 

• Emission Reduction 91 percent; 

• Rule Penetration 99 percent; 

• Rule Effectiveness 40 percent; and 

• Overall Control Reduction 36 percent. 

Applying these overall control reduction to the 2001 

emissions for this source category yields the following 

emission reductions: 

• Baseline Emissions: 33,100 TPY 

• Controlled Emissions: 21,184 TPY 

• Emission Reductions: 11,916 TPY 

Emission Reductions 

from Disturbed Vacant 

Land 
 4-91 

4.5.3.1.6 Control Measure Costs: A range of costs has 

been calculated for this regulation due to the following 

factors: 

• The rule allows a number of alternative control 

options that may differ widely in cost; 

• The cost for a given option may vary 

considerably with the size of area to be treated 

and onsite impacts such as vehicular traffic; and 

• Specific site conditions such as soil type may 

significantly impact costs. 

The following control measure costs and assumptions 

were utilized in developing cost effectiveness estimates: 

• Fencing Cost30 –Acre per year (based on cost of 

renting fencing) $2,000; 

• Stabilization Cost31 – Acre per application: $500 

to $1,500; 

• Number of Applications per year: one to three 

(assume less expensive material will need to be 

applied more frequently); 

• Cost Range per acre per year: $500 to $2,000; 

and 

• Cost of Enforcement: $540,540. 

Public cost of enforcement must also be considered 

when calculating control measure cost effectiveness. As 

noted in the discussion of commitments for additional 

Air Quality Division (AQD) enforcement staffing levels in 

this chapter, the total cost per year of this expanded 

effort, with the exception of certain administrative costs, 

is $780,000.32 Adjusting for the administrative cost and 

assuming 63 percent of the enhanced enforcement 

effort will be applied to disturbed vacant lands, it is 

estimated that the total enforcement cost per year 

 

30 Memorandum #08-00 to Clark County Health District Board of 

Health, May 25, 2000 

31 Ibid. 

32 Naylor, M.H., Workplan for PM10 Resources Commitment, 

Prepared for Clark County Health District Board of Health, July 11, 

2000. 

Disturbed Vacant Land 

Control Costs 
 4-92 

attributed to this control measure will be $540,540.33 

The number of acres of disturbed open areas or vacant 

lots that are subject to these control measures is 

estimated to be 12,766 acres34 in the 2001 annual 

valley-wide emission inventory (Appendix E, Table E-9). 

This acreage is multiplied by the low and high cost per 

acre ($500 and $2,000) to calculate the control measure 

cost per year. Enforcement cost per year is added to 

the low end and high end control cost to calculate the 

total control cost per year. Dividing these numbers by 

the emission reductions (11,916 TPY) yields the cost 

effectiveness for this control measure. 

 

Therefore, applying the above control cost to the 

acreage subject to the control measure on the per-day 

basis yields the following cost factors. 

 Low High 

Control Measure 

Cost/Year $6,383,000 $25,532,000 

Enforcement Cost/Year $540,540 $540,540 

Total Control Cost/Year $6,923,540 $26,072,540 

Cost Effectiveness $581 per 

ton 

$2,188 per 

ton 

The Clark County Health District Board of Health has 

adopted Section 90 of the Air Quality Regulations as 

RACM and BACM for this emission source category. 

4.5.3.2 Control Measures For Unpaved Parking Lots 

(Annual Standard)

4.5.3.2.1 Sources Controlled: Unpaved parking lots. 

4.5.3.2.2 Implementation Schedule: Control 

measures must be applied to new parking lots 

constructed after June 22, 2000. Control measures 

must be applied to existing parking lots by July 1, 2001. 

 

33 The estimated cost for enforcing Section 90 is based on the 

assumption that 63 percent of the new enforcement cost will be 

allocated to Section 90. Unaccounted administrative costs are 

estimated to be ten percent of the operational cost. Therefore, 

Section 90 enforcement costs are calculated as follows: 

$780,000x0.63x1.10=$540,540 

34 This acreage includes unpaved parking lots. 
 4-93 

4.5.3.2.3 Description of Control Strategy: See 

Description Of Control Strategy discussion in Control 

Measures For Unpaved Parking Lots (24-Hour 

Standard) Section 4.5.2.2.3. 

4.5.3.2.4 Technical Feasibility and Environmental 

Impacts: See Technical Feasibility and Environmental 

Impacts discussion in Control Measures For Unpaved 

Parking Lots (24-Hour Standard) Section 4.5.2.2.4. 

4.5.3.2.5 Emission Reductions: Because the extent of 

unpaved parking lots affected by this regulation has not 

been determined on a valley-wide basis, emission 

reductions from this regulation were calculated using 

acreage of unpaved parking from the two “worst 

case” micro-scale areas that contained unpaved 

parking. A total of 21 acres of unpaved parking was 

found in the Pittman micro-scale area and 18 acres of 

unpaved parking was found in the Craig Road microscale area. The emission reductions, rule penetration, 

rule effectiveness, and overall reduction are detailed in 

Appendix L and shown below for the year 2001: 

• Emission Reductions-Wind: 91 percent; 

• Emission Reductions-Vehicle: 60 percent; 

• Rule Penetration-Wind: 99 percent; 

• Rule Penetration-Vehicle: 100 percent; 

• Rule Effectiveness-Wind: 40 percent; 

• Rule Effectiveness-Vehicle 40 percent; 

• Overall Reduction-Wind: 36 percent; and 

• Overall Reduction-Vehicle: 24 percent. 

 

The uncontrolled baseline emissions, controlled 

emissions, and emission reductions for wind and vehicle 

emissions from the 39 acres of unpaved parking are 

listed below. Emissions from the two micro-scale sites 

were calculated on a daily basis for the design day; 

therefore, the emissions have been “annualized” by 

multiplying by 365. These emission estimates are 

assumed to overestimate emissions from this source 

category. 

• Baseline Emissions (Wind): 591.3 TPY 

• Controlled Emissions (Wind): 378.4 TPY 

• Emission Reductions (Wind): 212.9 TPY 

 

Unpaved Parking Lots 

Control Measures 
 4-94 

• Baseline Emissions (Vehicle): 12.41 TPY 

• Controlled Emissions (Vehicle): 9.41 TPY 

• Emission Reductions (Vehicle): 2.99 TPY 

4.5.3.2.6 Control Measure Costs: A range of costs 

has been calculated for this control measure due to the 

following factors: 

• The rule allows several alternative control options 

that may differ significantly in cost; 

• The cost for a given option may vary considerably 

with the size, frequency of use, and intensity of use 

of the parking lot to be treated; and 

• Specific site conditions, such as soil type, may 

significantly impact costs. 

The following control measure costs and assumptions 

were utilized in developing cost-effectiveness estimates: 

• Annual Control Measure Cost (Paving): $1,722 to 

$4,300; 

• Annual Control Measure Cost (Dust Palliatives): 

$1,000 to $2,000; and 

• Annual Control Cost Range: $1,000 to $4,300. 

The public cost of enforcing the requirements for 

unpaved parking lots cannot be accurately separated 

from the cost of compliance enforcement of disturbed 

open areas and vacant land, but are expected to be a 

relatively small part of the $540,540 annual enforcement 

cost for this source category. The public cost of 

compliance enforcement is not considered in this cost 

assessment for unpaved parking lots. 

The cost effectiveness of this control measure for windgenerated emissions is calculated as follows. The 

number of acres of unpaved parking lots from the microscale areas is 39 acres. This acreage is multiplied by 

the low and high annual control cost per acre ($1000 

and $4,300) to get the control measure cost per year. 

Dividing these numbers by the wind erosion emission 

reductions achieved (212.9 tons per year) gives the low 

and high end cost effectiveness from this control 

measure for wind- generated emissions from unpaved 

parking lots. 

Emission Reductions 

from Unpaved Parking 

Lots 
 4-95 

 Low High 

Control Measure 

Cost/Year $39,000 $167,700 

Emission Reductions 212.9 TPY 212.9 TPY 

Cost Effectiveness $183 per ton $788 per ton 

The cost effectiveness of this control measure for 

vehicle-generated emissions is calculated as follows. 

The number of acres of unpaved parking lots from the 

micro-scale areas is 39 acres. This acreage is 

multiplied by the low and high annual control cost per 

acre ($1000 and $4,300) to get the control measure cost 

per year. Dividing these numbers by the vehiclegenerated emission reductions achieved (2.99 tons per 

year) gives the low and high end cost effectiveness from 

this control measure for vehicle-generated emissions. 

Low High 

Control Measure 

Cost/Year $39,000 $167,700 

Emission Reductions 2.99 TPY 2.99 TPY 

Cost Effectiveness $13,044 per 

ton 

$56,087 per 

ton 

The Clark County Health District Board of Health has 

adopted Section 92 of the Air Quality Regulations as 

RACM and BACM for this emission source category. 

4.5.3.3 Control Measures For Construction Activities 

(Annual Standard)

4.5.3.3.1 Sources Controlled: Construction activities 

and related emissions. 

4.5.3.3.2 Implementation Schedule: These control 

measures must be implemented on construction sites 

beginning on January 1, 2001. 

4.5.3.3.3 Description of Control Strategy: See 

Description Of Control Strategy discussion in Control 

Measures For Construction Activities (24-Hour 

Standard) Section 4.5.2.3.3. 

Cost Effectiveness 

 for Unpaved 

Parking Lots 

Construction Activities 

Control Measures 
 4-96 

4.5.3.3.4 Technical Feasibility and Environmental 

Impacts: See Technical Feasibility and Environmental 

Impacts discussion in Control Measures For 

Construction Activities (24-Hour Standard) Section 

4.5.2.3.4. 

4.5.3.3.5 Emission Reductions: All emission reduction 

computations are based on the 2001 attainment year for 

the annual NAAQS. The rule applies to the PM10

emission source categories “Construction Activity 

Fugitive Dust” and “Windblown Construction Dust.” 

“Highway Construction Activity Fugitive Dust” and 

“Highway Construction Projects-Wind Erosion” were 

broken out separately from other construction activities 

in the Chapter 3 emission inventories for transportation 

conformity purposes, but have been included with the 

other construction activities for the purposes of this 

analysis. Control factors for highway-related 

construction activities are identical to those for other 

types of construction. This control measure applies to 

all of Clark County, so the actual reductions achieved 

are greater than those applicable to the Las Vegas 

Valley and factored into the attainment demonstration. 

The emission reductions, rule penetration, rule 

effectiveness, and overall reduction for the year 2001 

are shown below: 

Emission Reductions: 

• Construction Activity Fugitive Dust: 80 percent; 

• Windblown Construction Dust: 91 percent; 

Rule Penetration: 

• Construction Activity Fugitive Dust: 98 percent; 

• Windblown Construction Dust: 98 percent; 

Rule Effectiveness (2001): 

• Construction Activity Fugitive Dust: 40 percent; 

• Windblown Construction Dust: 40 percent; 

Overall Reduction (2001): 

• Construction Activity Fugitive Dust: 32 percent; 

• Windblown Construction Dust: 36 percent;a

a

 As noted in Appendix L, wind erosion emissions from 

construction sites were calculated assuming a 

percentage of each construction site was already 

controlled under regulations (i.e., RACM) already in 

place and not measures adopted as part of the SIP. 

Therefore, the percent reduction calculated for the 
 4-97 

SIP- adopted measures is applied to those portions of 

the site not already being controlled. Therefore, actual 

emission reductions achieved are less than the 

reductions that would be achieved by applying the 

control measure to an uncontrolled source. 

Applying these overall control reductions to the 2001 

annual uncontrolled emissions yields the following 

emission reductions: 

• Baseline Emissions (Activity): 25,891 TPY 

• Controlled Emissions-(Activity): 17,088 TPY 

• Emission Reductions-(Activity): 8,803 TPY 

• Baseline Emissions (Wind): 19,851 TPY 

• Controlled Emissions-(Wind): 12,812 TPY 

• Emission Reductions-(Wind): 7,039 TPY 

4.5.3.3.6 Control Measure Cost: Dames & Moore35

found that the cost of controlling dust during grading on 

a 40 acre parcel with soils categorized as “Low” for PEP 

would typically be $1,700 per day, or $43 per acre per 

day. This cost is predicated on the application of 

200,000 gallons of water. The water application rate 

and cost would double for a parcel with soils 

categorized as “High” for PEP. Therefore, the cost per 

acre per day for controlling dust from grading operations 

ranges from $43 per acre per day to $86 per acre per 

day. The projected acreage of construction occurring 

valley-wide in 2001 is 22,691 acres as shown in 

Appendix E, Table E-5. However, not all of this 

construction acreage is active during the entire year as 

discussed in Appendix B. Using the average length of 

construction by type of construction project, the number 

of acres on any given day can be calculated. The 

acreage under construction in 2001 averages 350 acres 

per day. 

Grading is the most dust-intensive phase of a 

construction project. Cost estimates for dust

 

35 Dames & Moore, An Evaluation of Incorporating Best 

Management Practices into the Construction Activities Program,

document 44499-001-128, prepared for the Clark County Health 

District Board of Health, p. 13 

Construction Activity 

Emission Reductions 

Construction Activity 

Control Costs 
 4-98 

control during other phases of a construction project 

under this control measure have not been developed by 

industry and are currently not known. Once cost factors 

have been developed by industry for compliance, a 

more detailed cost analysis can be completed. Because 

of the unavailability of cost factors for other 

requirements in the control measure, the cost analysis 

for this control measure is based on cost effectiveness 

per acre for control of dust from grading operations and 

will overestimate the compliance cost for most other 

types of construction activities. 

The cost of enforcement to the local air agency is 

calculated as follows. The cost of additional AQD 

enforcement staffing levels for the implementation of 

this regulation is calculated to be $285,714 per year.36 

The annual cost of compliance per acre is calculated by 

multiplying the low and high cost per day by 365. These 

annual costs per acre controlled are $15,965 and 

$31,390 respectively. The cost of compliance is 

calculated by multiplying the cost per year of control by 

the number of acres per day that must be controlled 

each day. The low and high control costs are calculated 

as follows: 

Low Cost: $15,695 x 350 acres = $5,493,250; 

and 

High Cost: $31,390 x 350 acres = $10,986,500. 

Adding the cost per year of enforcement to the total low 

and high cost of controls gives the total cost of 

implementing the control measure. These low and high 

costs for control measure implementation are 

$5,778,964 and $11,272,214 respectively. Dividing the 

total control measure implementation cost by the 

emission reductions achieved by the control measure 

gives the cost effectiveness for the control measure. 

 

36 The estimated cost for enforcing Section 94 is based on the 

assumption that 33 percent of the new enforcement cost will be 

allocated to enforcing Section 94. Unaccounted administrative 

costs are estimated to be ten percent of the operational cost. 

Therefore, Section 90 enforcement costs are calculated as follows: 

$780,000x0.3x1.10=$285,714. 
 4-99 

Low High 

Total Cost Per Day $5,778,964 $11,272,214

Emission Reductions (Wind 

and Activity) 15,842 tons 15,842 tons 

Cost Effectiveness $365 per 

ton 

$712 per 

ton 

The Clark County Health District Board of Health has 

adopted Section 94 of the AQR as RACM and BACM for 

this emission source category. 

4.5.3.4 Control Measures For Paved Road Dust 

(Annual Standard)

4.5.3.4.1 Sources Controlled: Paved roads. 

4.5.3.4.2 Implementation Schedule: The 

requirements of these control measures became 

effective on January 1, 2000. 

4.5.3.4.3 Description of Control Strategy: See 

Description Of Control Strategy discussion in Control 

Measures For Paved Road Dust (24-Hour Standard)

Section 4.5.2.4.3.

4.5.3.4.4 Technical Feasibility and Environmental 

Impacts: See Technical Feasibility and Environmental 

Impacts discussion in Control Measures For Paved 

Road Dust (24-Hour Standard) Section 4.5.2.4.4. 

4.5.3.4.5 Emission Reductions: All emission reduction 

computations are based on the 2001 attainment year for 

the annual NAAQS. Because a very large proportion of 

the existing fleet of publicly owned and operated streetsweeping equipment in Clark County complies with this 

regulation, no emission reductions have been taken that 

would otherwise be achieved through the PM10-efficient 

sweeper requirements. The emission reductions from 

this control measure are reflected in the emission 

inventory baseline. This control measure also applies to 

private operators of sweeping equipment. The impact of 

this regulation on these privately owned sweeping fleets 

is not known, but is likely to be insignificant, and was not 

factored into this attainment demonstration. 

Paved Road Dust 

Control Measures 

Sweeper Fleets Not 

Factored In 
 4-100 

Entrained/re-entrained fugitive dust emissions from 

paved roads are dependent on silt loadings deposited 

on all classes of paved roads from all sources and 

Vehicle Miles Traveled (VMT) on these roads. 

Reductions in silt loadings do not result in linear 

percentage reductions of PM10 emissions. Because 

PM10 emissions generated from paved roads are 

dependent on both silt loadings and VMT for each 

roadway type, emission reductions must be computed 

separately by VMT and silt loading for each road class. 

The attainment demonstration for the annual standard is 

based on the J. D. Smith micro-scale site. The valleywide annual emission inventory was based on the J. D. 

Smith micro-scale site. The reduction in silt loading that 

will occur in 2001 due to reduced deposition from 

emissions from other sources is 15 percent. When the 

15 percent silt reduction was applied to the paved road 

miles with improved shoulders by class and VMT mix at 

the J. D. Smith micro-scale site, a ten percent reduction 

in overall emissions was achieved. In order to ensure 

consistency between the valley-wide 2001 annual 

emission inventory and the J. D. Smith attainment 

demonstration, the same overall emission reduction was 

applied to the paved road emissions in the valley-wide 

inventory. This is a conservative approach in that 

applying the 15 percent silt reduction to the valley-wide 

road mix would result in somewhat larger emission 

reductions. 

Because there were not unimproved shoulders in the 

J. D. Smith micro-scale site boundary, no reductions 

were taken in the valley-wide emission inventory for the 

improvement of unimproved shoulders. 

The controlled and uncontrolled entrained/re-entrained 

fugitive dust emission for paved roads from the 2001 

Valley-Wide Annual Emission Inventory that are 

presented in Chapter 5 and Appendix L are shown 

below: 

• Total Uncontrolled Paved Road Emissions:

 55,350 TPY 

• Total Controlled Paved Road Emissions:

50,239 TPY 

• Uncontrolled Paved Road Dust Emissions:

 41,115 TPY 

Paved Road Dust 

Emissions Dependent 

on Silt Loading and 

VMT 

Emission Reductions 

from Paved Roads 
 4-101 

• Controlled Paved Road Dust Emissions: 

 37,004 TPY 

a

 Total uncontrolled and controlled paved road 

emissions include emissions that result from 

unimproved shoulders throughout the valley. This 

emission source was not controlled in the annual 2001 

valley-wide inventory in order to maintain consistency 

with the J. D. Smith attainment demonstration. 

4.5.3.4.6 Control Measure Costs: No emission 

reduction credit was taken for improving unimproved 

shoulders or for utilization of certified PM-efficient street 

sweeping equipment in the 2001 Annual Valley-Wide 

emission inventory. Therefore, cost effectiveness of 

these control measures was not evaluated. 

The Clark County Health District Board of Health has 

adopted Section 93 and Section 94 of the AQR as 

RACM and BACM for this emission source category. 

4.5.3.5 Control Measures For Unpaved Road Dust 

(Annual Standard)

 4.5.3.5.1 Sources Controlled: All publicly and 

privately owned unpaved roads, including unpaved 

alleys, unpaved easement roads, and unpaved access 

roads. 

4.5.3.5.2 Implementation Schedule: The 

requirements of this regulation became effective on 

June 22, 2000 for the construction of new publicly 

owned and maintained and privately owned unpaved 

roads. Owners and/or operators of existing unpaved 

roads having vehicular traffic of 150 vehicle trips or 

more per day are required to apply control measures to 

one-third of the total road miles by June 1, 2001; apply 

control measures to two-thirds of the total road miles by 

June 1, 2002; and apply control measures to all 

unpaved roads having vehicular traffic of 150 vehicle 

miles or more per day by June 1, 2003. 

4.5.3.5.3 Description of Control Strategy: See 

Description Of Control Strategy discussion in Control 

Measures For Unpaved Road Dust (24-Hour Standard)

Section 4.5.2.5.3. 

Publicly, Privately 

Owned Unpaved 

Roads Dust Control 

Measures 
 4-102 

4.5.3.5.4 Technical Feasibility and Environmental 

Impacts: See Technical Feasibility and Environmental 

Impacts discussion in Control Measures For Unpaved 

Road Dust (24-Hour Standard) Section 4.5.2.5.4. 

4.5.3.5.5 Emission Reductions: The rule applies to 

the PM10 emission source category “unpaved road dust” 

with total PM10 emissions of 18,932 TPY in the PM10

2001 Annual Valley-Wide Emission Inventory. The 

attainment demonstration for the annual standard is 

based on the J. D. Smith micro-scale site. Therefore, 

the valley-wide annual emission inventory was based on 

the J. D. Smith micro-scale site. No unpaved roads with 

greater than 150 vehicle trips per day were located 

within the J. D. Smith micro-scale inventory area so no 

reduction from this source category was calculated for 

the J. D. Smith annual inventory. As the valley-wide 

annual attainment is based upon the attainment at the 

J. D. Smith monitoring station and the controls 

implemented within this micro-scale area, no reduction 

in unpaved road dust was applied to the valley-wide 

annual inventory in 2001 for purposes of attainment 

demonstration. This is a conservative estimate, as rules 

regarding the paving of unpaved roads over 150 vehicle 

trips per day will be in place and enforced during 2001. 

4.5.3.5.6 Control Measure Costs: No emission 

reduction credit was taken for paving unpaved roads in 

the annual attainment demonstration or included in the 

PM10 2001 Annual Valley-Wide Emission Inventory. 

Therefore, cost effectiveness of these control measures 

was not evaluated. 

4.6 INSIGNIFICANT SOURCE CATEGORIES 

The determination of source significance is based 

primarily on the J. D. Smith annual inventory and the 

24-hour micro-scale inventories at the five 

representative sites, supplemented by reviews of the 

1998 valley-wide 24-hour emission inventory, the 1998 

valley-wide annual emission inventory, and Chemical 

Mass Balance (CMB) modeling. A significant source is 

defined in U. S. EPA’s Addendum to General 

Preamble,37 as a source that contributes more than five 

μg/m3

 to a 24-hour violation and more than one μg/m3 to 

 

37 Federal Register, FRL-5052-2, August 16, 1994 

Unpaved Road Dust 

Emissions 

Insignificant Sources 

Contribute Less Than 

One μg/m3 
 4-103 

an annual violation. Sources with lower contributions to 

a violation are presumed to be de minimis. 

4.6.1 De Minimis Source Categories – 24-Hour PM10

NAAQS 

Applying the above criteria, the anthropogenic source 

categories shown in Table 4-16 are found to be de 

minimis for the 24-hour PM10 NAAQS in the 1998 base 

year. 

Table 4-16 

De Minimis Source Categories – 24-Hour NAAQS 

SOURCE 

CATEGORY

Craig 

Road 

24-Hour

(μg/m3) 

East 

Flamingo 

24-Hour 

(μg/m3) 

Green 

Valley 

24-Hour 

(μg/m3) 

J.D. 

Smith 

24-Hour 

(μg/m3) 

Pittman 

24-Hour 

(μg/m3) 

24-Hour 

ValleyWide 

(μg/m3) 

STATIONARY SOURCES 3.53 0.13 1.34 0.08 3.74 

Sand & Gravel Operations 0.50 

Utilities – Natural Gas 0.16 

Asphalt Concrete Manufacture 0.14 

Industrial Processes 0.06 

Other Stationary Point Sources 0.10 

Small Point Sources 0.15 

Residential Firewood 0.24 

Residential Natural Gas 0.05 

Commercial Natural Gas 0.03 

Industrial Natural Gas 0.01 

NG – Purchased at the sourceCarried by SWG 0.17 

Structural/Vehicle/Wildfires 0.01 

Charbroiling/Meat Cooking 0.60 

NONROAD MOBILE SOURCES 

Airport Support Equipment 0.03 

Commercial Equipment 0.00 

Construction and Mining 

Equipment 0.29 

Lawn & Garden Equipment 0.01 

Railroad Equipment 0.01 

Recreational Equipment 0.00 

McCarran International Airport 0.20 

Henderson Executive Airport 0.00 

North Las Vegas Municipal Airport 0.02 

Nellis Air Force Base 0.03 
 4-104 

Table 4-16 

De Minimis Source Categories – 24-Hour NAAQS 

(continued) 

ONROAD MOBLE SOURCES 

Vehicular Sulfate PM 0.32 

Vehicular Tire Wear 0.07 

Vehicular Brake Wear 0.11 

Vehicular Exhaust (Carbon PM) 1.47 1.68 0.55 1.66 0.62 0.28 

4.6.1.1 Stationary Sources

As shown in Chapter 3, stationary sources, including 

sand and gravel operations; natural gas-fired utility 

power plants; asphalt concrete plants; industrial 

processes; and other stationary sources, generated 

3.29 tons per day valley-wide during the 24-hour design 

day. The tonnage for this source category is projected 

to remain unchanged through 2006. By equating the 

1998 base year 24-hour design day emission total of 

931.95 tons per day with the design concentration 

(which occurred in 1998) of 281 μg/m3

 and allowing for 

the background concentration of 10.5 μg/m3

, the 

contribution of all stationary source emissions to the 

design day concentration is calculated to be 0.95 μg/m3. 

Stationary point sources are projected to contribute the 

same PM10 mass to the 24-hour design day in 2006. 

At the micro-scale level, a review of the design day 

micro-inventories indicated that stationary source 

emissions at the Pittman (3.68 μg/m3

) and Craig Road 

(3.53 μg/m3

) monitoring sites came close to, but fell 

below, the U. S. EPA thresholds of presumed 

significance for this source category. 

The relatively constant emissions from stationary 

sources are predicated on 1) current trends for this 

source category, which show a slight decrease in 

emissions from 1994 to 1998; 2) the fact that BACT 

controls are required for new and modified sources 

which produce more than two tons; and 3) Lowest 

Achievable Emission Reductions (LAER) that are 

required for all major sources which have been 

constructed or modified after September 26,1996. 
 4-105 

Declining rates of population growth and construction 

activity would be expected to decrease activity levels in 

the sand and gravel operations and asphalt concrete 

manufacturing categories. To the extent that other 

stationary source categories may grow in proportion to 

the overall population, the BACT and LAER 

requirements will ensure that all stationary point source 

emissions will remain at the de minimis level. 

The requirements for BACT controls for potential 

emissions over two tons and LAER requirements for all 

new and modified sources with the potential to emit 

more than 70 tons of PM10 are set forth under 

Section 12 of the AQR. Section 12 was formally 

approved by the U. S. EPA as part of the Nevada SIP 

on May 11, 1999.38 In addition to a stationary source’s 

emission units, the Section 12 BACT requirements also 

apply to all fugitive emissions generated by the 

permitted facility. The definition of BACT found in the 

first sentence of AQR Section 0 - Definitions, indicates 

that BACT is the “maximum degree of reduction for 

each pollutant ... which the Control Officer, on a caseby-case basis, taking into account energy, 

environmental, and economic impacts and other costs, 

determines is achievable ... for control of such 

pollutant.” Clark County interprets this to mean that the 

level of control representative of BACT for permitted 

sources with fugitive emissions is no less stringent than 

that required to meet BACM for those fugitive sources. 

Fugitive emissions at a stationary source are those not 

emitted through a stack or duct and, therefore, include 

PM10 sources such as disturbed vacant lands, unpaved 

roads/haul roads, and track out onto paved roads. 

Stationary sources are required to apply BACT to their 

fugitive dust sources to be at least as stringent as the 

standards in the applicable Regulations 90, 91, 92, and 

94. 

The requirement to apply BACT to fugitive dust sources 

is established by the conditions contained in the 

Authority to Construct Certificate issued by the Control 

Officer in accordance with the provisions of Section 12. 

 

38 Federal Register, Vol. 64. No. 90, May 11, 1999, pages 25210 - 

25213 

BACT Required for 

Stationary Sources 

with a Potential To 

Emit Greater than Two 

Tons 

All Major PM10 Sources 

Required To Apply 

BACT or LAER 
 4-106 

All sources with the potential to emit of 70 tons or 

greater in the PM10 nonattainment area are listed below: 

Wells Cargo – LAER; 

Nevada Power-Sunrise (including the State regulated 

sources) – BACT; 

Nevada Power-Clark – BACT; 

James Hardie Gypsum – BACT; 

Chemical Lime Henderson – BACT; 

Timet – BACT; and 

CSR West – BACT. 

Wells Cargo, Inc. is currently undergoing a permit 

modification that will require either BACT or LAER for all 

PM10 emission units at the facility. Currently, the facility 

has some emission units that meet the BACT standard. 

In addition to stationary sources, the AQD also issues 

permits to sources with a potential to emit greater than 

one ton but less than 15 tons that are located at a site 

less than 365 continuous days. The sources are issued 

variable location permits (VLPs) and must also meet 

stringent control standards. The following permit 

conditions for VLPs are contained in AQD guidelines: 

• Minimum moisture content of processed 

materials of 1.5 percent; and 

• Haul roads controlled to 90 percent by use of 

water, dust suppressants, sealing or paving. 

Beginning January 1, 2001 a new requirement for 

disturbed soil to pass the test standards adopted in 

Section 90 of the AQR was added to the guidelines. 

Currently, the requirements for material being handled 

or stockpiled to have a 1.5 percent minimum moisture 

content and loose soil to be stabilized are being 

incorporated into VLP permits. 

The AQD does have a program for minor source 

emission reduction credits that is administered locally. 

Credits are usually generated by paving unpaved roads. 

The credits are then used to offset minor source 

emissions by a 2-to-1 ratio as described in Section 12 of 

the AQR. Credits are not pollutant specific and 

VLPs Also Required to 

Have BACT 
 4-107 

reductions of one pollutant can be used to offset a 

different and sometimes unrelated pollutant. For 

example, emission reduction credits generated by 

paving a road and reducing PM10 emissions by 100 tons 

can be used to offset 50 tons of carbon monoxide 

emissions. This program is not used for major sources 

and has not been used to determine emission 

inventories or as part of the rollback modeling in this 

SIP. However, the requirement for offsets for new or 

modified minor sources may be a further deterrent for 

an increase in emissions because emission increases 

would require offsets and the facility would incur 

additional expenses. 

In addition to Section 12 of the Air Quality Regulations, 

Section 445.389 of the Nevada Administrative Code 

(NAC) prohibits the construction or modification of fossilfuel-powered electricity generation plants in 

Hydrographic Basin 212 and the city limits of Boulder 

City. This requirement will further limit the potential for 

additional emissions from stationary sources. 

Two of the source categories projected to increase in 

proportion to population growth, structural/vehicle 

fires/wild fires and residential natural gas, are very small 

sources that will remain far below the de minimis level. 

The charbroiling/meat cooking source category is larger, 

but emissions from the sources with potential to emit 

greater than two tons within this category are subject to 

BACT requirements under Section 12. 

Residential firewood combustion is projected to increase 

in proportion to population growth. New fireplaces are 

restricted to U. S. EPA Certified Phase II wood burning 

stoves or cleaner alternative non-wood burning devices 

such as gas logs. These requirements are implemented 

through Clark County Ordinance 1249, City of Las 

Vegas Ordinance 3538, City of North Las Vegas 

Ordinance 1020, and City of Henderson Ordinance 

1997. These control measures will prevent emissions 

from this source category from approaching or 

exceeding the de minimis source threshold level for this 

source category. 

As detailed under the commitments section of this 

chapter, Clark County has committed to conducting a 

Minor Source 

Emission Reduction 

Credits Administrated 

Locally 

State Law Prohibits 

New Fossil-FuelPowered Power Plants 

in the Nonattainment 

Area 

Residential Fireplaces 

Restricted Under 

County Ordinance 
 4-108 

PM10 saturation study to further evaluate the impacts of 

stationary sources on neighborhood scale PM10

concentrations. If stationary sources are found to have 

significant impacts on neighborhood PM10

concentrations, then Clark County will develop and 

adopt U. S. EPA approvable rules that require the 

implementation of BACT for all stationary sources. 

4.6.1.2 Nonroad Mobile

The de minimis source categories in the nonroad mobile 

sources grouping are projected to remain relatively 

constant, grow in proportion with population growth, or 

grow in proportion to airport activity. Of these source 

categories, only two contribute more then 0.03 μg/m3 to 

the 1998 base year 24-hour design value. These are 

the construction and mining category and McCarran 

International Airport. Construction and mining 

equipment is projected to grow in proportion to 

population growth. This source category contributed 

0.29 μg/m3 to the 1998 base year 24-hour design value 

and is projected to contribute 0.94 μg/m3

 to the 2006 

attainment year 24-hour design value. This is a 

conservative projection. Actual use of construction 

equipment by 2006 could actually decline in proportion 

with the declining growth rate. Emissions from 

McCarran International Airport contributed 0.20 μg/m3 to 

the 1998 base year 24-hour design value. Emissions 

from McCarran will decline in 2006 due to aircraft gate 

electrification and use of newer lower-emission aircraft 

at the facility. 

4.6.1.3 Onroad Mobile

Onroad mobile de minimis sources include vehicular 

sulfate particulate, vehicular tire wear, vehicular brake 

wear, and vehicular exhaust (carbon particulate). These 

contribute 0.32 μg/m3

, 0.07 μg/m3, 0.11 μg/m3, and 0.28 

μg/m3

 respectively to the 1998 base year 24-hour 

design value. Projected increases in vehicle miles 

traveled are shown for each road category in Table E-14 

of Appendix E. Vehicles are expected to produce less 

particulate and sulfate emissions per mile traveled in 

2006 than in the 1998 base year based on emission 

factors in the Mobile5b and Part5 models. These 

emission factors are developed using federal 

automotive exhaust standards. Applying these factors, 

it is found that there will be a slight decrease in 

Projected Emissions 

of Nonroad Mobile 

Sources Stay Below 

the Level of 

Significance in 2006 

Vehicle Exhaust, Tire 

Wear, and Brake 

Emissions Remain De 

Minimis in 2006 
 4-109 

emissions from the vehicular sulfate and vehicular 

exhaust categories in 2006 and a slight increase in 

emissions from the tire wear and brake wear categories. 

4.6.2 De Minimis Source Categories – Annual PM10

NAAQS 

Determination of source significance for the Annual 

PM10 NAAQS was based primarily on the 1998 annual 

micro-inventory at the J. D. Smith representative site 

and 1998 Base Year Valley-Wide PM10 Annual 

Inventory and supplemented by review of CMB 

modeling. A significant source is defined in U. S. EPA’s 

Addendum to General Preamble39 as a source that 

contributes one μg/m3 or more to an annual violation. 

Sources with lower contributions to a violation are 

presumed to be de minimis. 

Applying the above criteria, the source categories 

shown in Table 4-17 are found to be de minimis for the 

annual PM10 NAAQS in the 1998 base year. 

 

39 Federal Register, FRL-5052-2, August 16, 1994 

Table 4-17 

De Minimis Source Categories – Annual NAAQS 

SOURCE 

CATEGORY

J. D. Smith Annual 

(μg/m3) 

Valley-Wide Annual 

(μg/m3) 

STATIONARY SOURCES 0.05 

Sand & Gravel Operations 0.13 

Utilities – Natural Gas 0.04 

Asphalt Concrete Manufacture 0.04 

Industrial Processes 0.02 

Other Stationary Point Sources 0.03 

Small Point Sources 0.04 

Residential Firewood 0.02 

Residential Natural Gas 0.01 

Commercial Natural Gas 0.01 

Industrial Natural Gas 0.00 

NG – Purchased at the source-Carried by SWG 0.04 

Structural/Vehicle/Wildfires 0.00 

Charbroiling/Meat Cooking 0.16 

NONROAD MOBILE SOURCES 

Airport Support Equipment 0.01 

Commercial Equipment 0.00 

Construction and Mining Equipment 0.08 

Lawn & Garden Equipment 0.00 

Railroad Equipment 0.00 
 4-110 

Table 4-17 

De Minimis Source Categories – Annual NAAQS 

(continued) 

Recreational Equipment 0.00 

McCarran International Airport 0.05 

Henderson Executive Airport 0.00 

North Las Vegas Municipal Airport 0.00 

Nellis Air Force Base 0.01 

ONROAD MOBLE SOURCES 

Vehicular Sulfate PM 0.09 

Vehicular Tire Wear 0.02 

Vehicular Brake Wear 0.03 

Vehicular Exhaust (Carbon PM) 0.29 0.08 

4.6.2.1 Motor Vehicle Exhaust

There are two categories of motor vehicle exhaust: onroad and non-road. The on-road category includes 

tailpipe and tire wear emissions of primary PM10 from 

on-road vehicles including both gasoline and dieselpowered passenger cars, light-, medium-, and heavyduty trucks, buses, and motorcycles. The 1998 base 

year inventory shows total emissions from these 

sources to be 1,399 tons per year. 

The non-road category includes various “off-road” 

equipment that use a variety of engine types and fuels. 

Examples are construction equipment; lawn and garden 

equipment; railroad equipment; recreational equipment; 

and airport equipment. Total PM10 emissions from 

these sources in the 1998 base year inventory are 737 

tons per year. 

Measures to control vehicle emissions have been 

implemented at the national, state and local level. The 

following describe the measures implemented that 

reduce motor vehicle exhaust emissions in the Las 

Vegas Valley. Most of the state and local measures 

were implemented to reduce carbon monoxide 

emissions, and are documented in the Las Vegas Valley 

Carbon Monoxide State Implementation Plan dated 

August, 2000. Reduced particulate emission benefits 

from these measures are often negligible, and the 

reductions are generally not quantifiable due to 

limitations in available models, specifically the U. S. 

EPA Part5 model. 

Motor Vehicle Exhaust 

Likely To Stay De 

Minimis Because of 

Federal Controls 
 4-111 

Since 1994, U. S. EPA standards limited the sulfur 

content of diesel fuel for on-road diesel vehicles to 0.05 

percent by weight (500 ppm). Concurrently, Clark 

County adopted the 500 ppm low-sulfur diesel standard 

for all diesel fuel sold in Clark County (District Board of 

Health Regulations, Section 29, December 16, 1993). 

This rule, although not changing on-road diesel fuel 

composition, has reduced the non-road diesel fuel sulfur 

content by 85 percent from an uncontrolled average of 

approximately 3,300 ppm. The PM10 emission benefits 

from this measure and related costs cannot be 

calculated. Added costs, if any, are absorbed by the 

users. 

District Board of Health Air Quality Regulations, Section 

45, September 26, 1991, limits the idling of diesel truck 

or diesel bus engines to no more than 15 minutes. 

Nevada Administrative Code (NAC) 445B.576 restricts 

visible emissions from both gasoline and dieselpowered motor vehicles, and also prohibits idling the 

engine of a diesel truck or bus for more than 15 

minutes. A program for the control of emissions from 

motor vehicles is established in Nevada Revised 

Statutes 445B.700 to 445B.845 and implemented in 

NAC 445B.400-774. The following vehicle inspection 

programs are established under these statutes: 

Light-duty motor vehicles powered by diesel engines 

are required to pass an annual emission test in order 

to be registered in Clark County. The inspection 

criteria are established in Nevada Administrative 

Code (NAC) 445B.587, which includes a tampering 

inspection and an opacity test phase. 

NAC 445B.737-774 addresses the control of 

emissions from onroad heavy-duty motor vehicles. It 

establishes a program for random roadside smoke 

opacity testing utilizing the Society of Automotive 

Engineers Procedure SAE J1667, Snap-Acceleration 

Smoke Test Procedure for Heavy-Duty Diesel 

Powered Vehicles. In addition to the smoke opacity 

test, criteria for inspection for tampered or defective 

conditions are also established to determine that the 

vehicle’s emission control system is operating 

correctly. 

Annual Smog Checks 

Required for LightDuty Motor Vehicles 
 4-112 

The State’s Motor Vehicle Inspection Maintenance 

Program is provided for in NAC 445B.400-735. The 

provisions apply to all gasoline-powered motor vehicles, 

model year 1968 or later, that reside in the Las Vegas 

Valley. 

The State Department of Motor Vehicles and Public 

Safety has committed to implement a remote sensing 

program in the Las Vegas Valley which will target 

50 percent of the motor vehicles operating in Las Vegas 

in 2001 and increase to 90 percent of the local motor 

vehicle fleet by 2011.40 This commitment will provide 

substantial air quality benefits and assist in 

attaining/maintaining national ambient air quality 

standards. 

Additional state programs, other than vehicle 

inspections, established to reduce motor vehicle 

emissions include: 

An alternative fuel vehicle program, established 

under NAC 486A, which requires state and local 

government agencies to acquire cleaner burning 

alternative fuel vehicles. For fiscal year 1999-2000 

the rule required all regulated agencies to purchase 

qualifying alternative fuel vehicles at the rate of 75 

percent of all vehicle purchases. The rate increases 

to 90 percent for FY 2000-2001, and remains at 90 

percent for future years. 

The State Department of Motor Vehicles has 

established a “Smoking Vehicle Hotline” program in 

the Las Vegas Valley. Citizens can report smoking 

vehicles to the department to help identify and have 

repaired excessively smoking vehicles. 

A lower Reid Vapor Pressure (RVP) requirement for 

gasoline was established in 1995 in NAC 590.065. 

Also a carbon monoxide control measure, this action 

lowered the RVP limit of gasoline from 11.0 psi to 

9.0 psi. 

 

40 Letter from the Nevada Department of Motor Vehicles and Public 

Safety, August 28, 1995 

Additional local 

programs 

implemented to 

reduce emissions 

from gasoline motor 

vehicles specifically 

as 

Alternative Fuel 

Program Mandated 

by State Law 
 4-113 

carbon monoxide control measures include a wintertime 

Clean Burning Gasoline (CBG) program and an 

oxygenated gasoline program. 

CBG is a low-sulfur and low-aromatic fuel which 

helps to increase catalytic converter efficiency, 

resulting in lower CO as well as other emissions. 

District Board of Health Air Quality Regulations, 

Section 54, April 22, 1999, implemented the CBG 

program beginning October 1, 1999. 

The Clark County oxygenated fuel program requires that 

all gasoline sold in the County during the winter season 

(October 1 to March 31) contain 3.5 percent oxygen by 

weight, the maximum amount allowed. This mandate is 

being satisfied by the use of ethanol in lieu of MTBE. 

Air Quality Regulation, Section 53, September 27, 1997, 

governs this program. 

The Regional Transportation Commission of Clark 

County has implemented Transportation Control 

Measures/Travel Demand Management (TCM/TDM) to 

reduce vehicle emissions and offset growth in vehicle 

miles traveled (VMT). The following voluntary control 

measures are being implemented: employer based 

commuter incentive programs; telecommuting; and 

area-wide ridesharing programs. 

In addition to these state and local measures 

implemented to reduce mobile source emissions, U. S. 

EPA has initiated or has proposed actions that will 

further reduce emissions from diesel vehicles, both on 

and off road, in the future: 

Standards for on-road heavy-duty truck and bus 

engines were established for model years 1987-

2003. These standards, following the reduced sulfur 

content requirement (500 ppm) beginning in 1994, 

significantly reduce PM10 emissions and some NOx. 

In 1997, U. S. EPA adopted new standards for the 

2004 model heavy-duty engines, with the goal of 

further reducing NOx emissions. 

In May 2000, U. S. EPA announced proposed 

emission standards for model year 2007 and later 

heavy-duty highway engines. The proposal includes 

Wintertime Clean 

Burning Gasoline 

Program Helps To 

Reduce Sulfur 

Emissions and 

Increase Catalytic 

Converter 

Efficiency 

RTC Has 

Implemented 

Transportation 

Control Measures 

Heavy-Duty Diesel 

Truck and Bus 

Engine Standards 
 4-114 

two components: 1) diesel fuel regulation, and 2) 

emission standards. The fuel provisions would 

reduce the sulfur content in on-highway diesel fuel to 

15 ppm, down from the current 500 ppm, beginning 

in 2006. New engine standards would be phased in 

beginning in 2007. The super-low-sulfur diesel is the 

“technology enabler” necessary to the further 

development of advanced exhaust emission 

technologies that will reduce particulate matter 

emissions by 90 percent and NOx by 95 percent in 

2030. 

U. S. EPA’s off-road engine regulations are 

structured as a three-tiered progression to low 

emissions. Each tier involves a phase in (by 

horsepower rating) over several years. Tier 1 

standards phase in from 1996 to 2000. A more 

stringent Tier 2 standard for all engine sizes take 

effect from 2001 to 2006, and yet more stringent Tier 

3 standards for engines rated over 50 hp phase in 

from 2006 to 2008. The Tier 3 standards are 

expected to lead to emission control technologies for 

off-road engines that will be similar to the 2004 

controls for highway heavy-duty engines. 

The U. S. EPA regulations that improve diesel fuel 

composition and diesel engine emissions have been 

and will continue to be the most effective measures for 

reducing emissions of particulate and other pollutants 

from diesel engines. These programs are 

complemented by state and local programs as 

described above to contribute to the larger emission 

reductions that will be realized from the full 

implementation of the U. S. EPA emission reduction 

programs. When U. S. EPA-approved methodologies 

are available for calculating emission reductions from 

these programs, Clark County will complete an analysis 

and propose a SIP revision as appropriate. 

Although there are numerous programs initiated or in 

development to reduce vehicle emissions, there is 

limited information or guidance on methods to quantify 

the benefits that will be realized in terms of particulate 

matter reductions and their subsequent impact on 

improving ambient air quality. Several research projects 

Stricter Heavy-Duty 

Diesel Truck and 

Bus Engine 

Standards Begin in 

2007 

 

U. S. EPA Has 

Regulations for Diesel 

Fuel Composition 

Several Research 

Projects Are Funded 
 4-115 

are funded and in progress that are expected to provide 

better information about the contributions of specific 

sources of particulate in the Las Vegas Valley, and to 

identify potential control measures to reduce future 

emissions. These studies are discussed in more detail 

in this chapter in Section 4.7. 

4.6.2.2 Stationary Sources

J. D. Smith is the only monitoring station with an annual 

average exceeding the NAAQS. Stationary sources in 

the J. D. Smith micro-scale area generated 6.3 tons per 

year in the 1998 base year (see Chapter 3) and 

contributed 0.05 μg/m3

 to the annual design 

concentration. The stationary source contribution is 

derived by equating the J. D. Smith 1998 base year 

emission total of 4,511 tons per year with the design 

concentration of 53 μg/m3

 and allowing for a 

background concentration of 16.5 μg/m3

. The tonnage 

for this source category is projected to remain 

consistent through 2006. Stationary point sources 

would be expected to contribute a similar mass (0.05 

μg/m3) of PM10 to the annual design value in 2006. 

As shown in Chapter 3, stationary point sources, which 

include sand and gravel operations; natural gas-fired 

utility power plants; asphalt concrete plants; industrial 

processes; and other stationary sources, generated 

1,201 tons per year on an annual valley wide basis in 

the 1998 base year. The tonnage for this source 

category is projected to remain consistent through 2006. 

By equating the 1998 base year annual emission total of 

171,755 tons per year with the design concentration of 

53 μg/m3

 and allowing for a background concentration 

of 16.5 μg/m3

, total stationary source emissions are 

estimated to contribute 0.26 μg/m3

 to the design day 

concentration. Stationary point sources would be 

expected to contribute a similar amount of PM10 annual 

design value 2006. 

Stationary sources are not expected to increase in 

future years for the same reasons discussed for the 24-

hour standard: 1) current trends for this source 

category, which show a slight decrease in emissions 

from 1994 to 1998; 2) the fact that BACT controls are 

required for sources which produce more than two tons; 

3) Lowest Achievable Emission Reductions (LAER) are 

Stationary Sources 

Contribute Less than 

One μg/m3

 to the 

Annual Average 

Stationary Source 

Emissions in the 

Nonattainment Area 

Not Projected To 

Increase 
 4-116 

required for all major sources which have been 

constructed or modified after September 26, 1996. 

Residential firewood emissions, residential natural gas 

emissions, structural/vehicle/wildfires, and charbroiling/ 

meat cooking, are projected to increase in proportion to 

the projected population growth as detailed in Table E-1 

of Appendix E. Of the four emission sources projected 

to increase in proportion with the projected population 

growth, only one contributes more than 0.05 μg/m3

 to 

the annual design value on a valley-wide basis. 

Charbroiling and meat cooking contribute 0.16 μg/m3 to 

the annual design value. In 2001 and 2006 charbroiling 

and meat cooking will contribute 0.19 μg/m3 and 0.32 

μg/m3 respectively to the annual design values. New 

emissions from the larger sources within this category 

are subject to BACT requirements under Section 12, 

ensuring that this source category will not exceed the de 

minimis source threshold in the 2001 or 2006 attainment 

years. 

The residential firewood combustion source category is 

also subject to non-federal controls. This source 

category is projected to increase in proportion to 

population growth, but only contributes 0.02 μg/m3

 to 

the 1998 base year annual design value. This small 

source category is subject to the requirements of Clark 

County Ordinance1249, City of Las Vegas Ordinance 

3538, City of North Las Vegas Ordinance 1020, and City 

of Henderson Ordinance 1997. These ordinances 

restrict new fireplaces to U. S. EPA Certified Phase II 

wood burning stoves or cleaner alternative non-wood 

burning devices such as gas logs. Even in the face of 

potential cost increases for alternative home heating 

fuels, these control measures will limit emissions from 

this source category to levels that are far below the de 

minimis source threshold. 

4.6.2.3 Nonroad Mobile

The de minimis source categories within the nonroad 

mobile source category grouping are projected to 

remain relatively constant, grow in proportion with 

population growth, or grow in proportion to aviation 

activity as detailed in Table E-1 of Appendix E. Nellis 

Air Force Base emissions will remain constant. Of 

Residential Firewood 

Emissions Not 

Expected To Become 

Significant 

Construction and 

Mining Equipment 

Largest Nonroad 

Mobile Contributor to 

PM10 Emissions Other 

than Airports 
 4-117 

these source categories, the highest emissions are 

generated from construction and mining equipment and 

McCarran International Airport. Construction and 

mining equipment is projected to grow in proportion to 

population growth and contributes 0.08 μg/m3

 to the 

1998 annual base year, 0.09 μg/m3

 to the 2001 annual 

design value, and 0.15 μg/m3 to the 2006 annual design 

value. Actual use of construction equipment is likely to 

decline in proportion with the declining growth rate. 

Emissions from McCarran International Airport 

contribute 0.05 μg/m3 to the 1998 base year annual 

design value. These emissions will decline in future 

years due to aircraft gate electrification and use of 

newer, lower-emission aircraft. 

4.6.2.4 Onroad Mobile

Onroad mobile de minimis sources include vehicular tire 

wear and vehicular brake wear. These contribute 0.02 

μg/m3, and 0.03 μg/m3 respectively to the 1998 base 

year annual design value. Projected increases in 

vehicle miles traveled are shown for each road category 

in Table E-14 of Appendix E. These emission factors 

were generated using the Mobile5b and Part5 models. 

These models show a slight increase in emissions from 

the tire wear and brake wear categories in future years, 

contributing 0.02 μg/m3 and 0.03 μg/m3 in 2001 and 

0.04 μg/m3 and 0.06 μg/m3 in 2006. 

4.6.3 Contingency Measures 

Clark County Health District Board of Health adopted 

Resolution #03-00 on July 27, 2000 committing the 

Clark County Health District to evaluating the following 

candidate contingency measures for an assessment of 

suitability: 

• Reduce the site-specific dust mitigation plan 

requirements for construction activities from ten 

acres to five acres; 

• Require paving/stabilization of all unpaved roads 

with average daily traffic (ADT) equal to or 

exceeding 100 trips; 

• Provide for at least two additional field 

enforcement officers above and beyond those 

staff increases committed to in the State 

Implementation Plan; 

Contingency Measures 

Have Been Identified 

by the Clark County 

Health District Board 

of Health 
 4-118 

• Increase minimum penalties for violations or Air 

Quality Regulations for fugitive dust; and 

• Reduce the size threshold for requiring a dust 

control monitor (coordinator) at construction sites. 

The entire set of contingency measures provided in 

Section 4.6.3 will be automatically implemented if Clark 

County fails to meet the projected 2003 emissions 

reduction milestone. The emissions reduction benefit 

form these measures is 1,373 tons (Appendix B), which 

exceeds the 19.07 TPY emission reduction increment. 

4.7 CLARK COUNTY AIR QUALITY PROGRAMS 

4.7.1 Clark County Educational Programs 

4.7.1.1 Dust Control Class

The Air Quality Division (AQD) conducts a Dust Control 

Class for permit compliance education and public 

education. The class was initiated in 1997 and initially 

used as a remedial or corrective requirement for 

violators of the Section 41 fugitive dust regulation. 

In early 1998, the scope of the class was expanded to 

include a more thorough discussion of preventative 

measures. The requirement to complete the Dust 

Control Class was extended to include the on-site 

superintendents or construction foremen for each new 

dust control permit issued. Interested members of the 

public have also attended the class. Those completing 

the class successfully receive a Certificate of Training 

and a photo-identification attendance card. The Dust 

Control Class is instructed by AQD Enforcement 

Officers and by contract instructors. 

The class has been presented on numerous occasions 

to large employee groups of construction contracting 

companies, public utilities, and public agencies. When 

presented in this manner, the class discussion is 

modified to focus on the specific activities of the 

company or group. 

The AQD is in the process of shifting the focus of the 

dust control class to Section 94 of the Air Quality 

Regulations and the Section 94 Handbook. Special 

Dust Control Class 

Required To Obtain a 

Dust Control Permit 
 4-119 

classes are being conducted to familiarize the 

construction industry with these new requirements. 

4.7.1.2 Small Business Assistance Program

The AQD has contracted with the University of Nevada, 

Reno Business Education Program to work with small 

businesses to explain AQD Air Quality Regulations and 

foster compliance. 

4.7.1.3 Clark County Conservation District 

Education Program

The AQD has contracted with the Clark County 

Conservation District of Southern Nevada to develop an 

informational brochure that has been mailed to property 

owners who may be impacted by Section 90 

requirements. 

The AQD is currently assessing the feasibility of 

additional roles for the Conservation District. These 

might include acting as advisors to property owners on 

how to avoid receiving a corrective action order and/or 

how to best respond to a corrective action order. 

4.7.1.4 Construction Industry Training Programs

Some of the building trade associations in the Las 

Vegas Valley have indicated that they will be providing 

training materials and/or classes to their members on 

Section 94 and the Section 94 Handbook. These efforts 

are being developed on a voluntary basis by the 

industry in cooperation with the AQD. 

4.7.1.5 Environmental Monitoring for Public Access 

and Community Tracking (EMPACT) Project

The Las Vegas Valley EMPACT Website provides 

public access to time-relevant environmental data 

including air quality, water quality, and meteorological 

information. Hourly updates from the AQD monitoring 

network are available for all recorded levels of CO, 

PM10, and ozone, as well as site-specific meteorological 

data. Relevant health information related to the levels of 

pollution is also displayed in a format that is easily 

understood. 

The Las Vegas Valley EMPACT Website was 

developed with funding assistance from the U. S. EPA 

EMPACT Funded by 

U. S. EPA 
 4-120 

EMPACT program. The grant was awarded on a joint 

Nevada application by the CCDCP, the City of Las 

Vegas, and the National Weather Service. The CCDCP 

served as project coordinator for the website 

development, with funding provided to its project 

partners that included the AQD; the Conservation 

District of Southern Nevada; the University of Nevada, 

Las Vegas; and the Desert Research Institute. 

4.7.1.6 Visibility Assessment and Time-Relevant 

Reporting 

This ongoing study is funded via an EMPACT Grant 

from U. S. EPA and a grant from the 

Department of Motor Vehicles. This study provides 

time-relevant visibility data which can be accessed by 

the public via the internet. The study report will 

characterize visibility in the Las Vegas Valley in regards 

to spatial, diurnal, weekday/weekend, and seasonal 

patterns. An assessment of sources contributing to 

urban haze will be conducted as part of the study. Work 

will be coordinated with the SNAQS (See Section 

4.7.2.1). 

4.7.1.7 Dust Control Product and Equipment Trade 

Shows

Dust control product applicators, dust control product 

manufacturers, equipment manufacturers, building trade 

associations, and UNLV have indicated an interest in 

participating in dust control products and equipment 

trade show. The SCAQMD, San Joaquin Valley Unified 

Air Pollution Control District (SJVUAPCD), and Mojave 

Desert AQMD have all successfully co-sponsored air 

pollution control product and equipment shows that 

were focused on different target groups. 

The SCAQMD event was focused primarily on fugitive 

dust sources and included equipment such as street 

sweepers and dust suppressant products. The 

SJVUAPCD co-sponsored three events that were 

targeted primarily at the agricultural industry and 

emphasized dust suppressant products. The Mojave 

Desert AQMD sponsored two shows that were more 

general in scope and targeted all types of air pollution 

control equipment and products. 

Dust Suppressant 

Product Shows 

Provide a Great Deal 

of Information in One 

Place 
 4-121 

Clark County will explore the feasibility of organizing 

and co-sponsoring a dust control product and 

equipment show in the Las Vegas Valley. The targeted 

audience for the event would be the construction 

industry, public works agencies, and members of the 

general public. 

4.7.2 Clark County Air Quality Research 

4.7.2.1 Southern Nevada Air Quality Study (SNAQS)

This study is currently ongoing and focuses on 

measurement of primary particulate matter emissions 

from motor vehicle exhaust using LIDAR technology. 

Development of a GIS-based transportation model for 

the Las Vegas Valley and determining the frequency 

and magnitude of PM2.5 transported into the Las Vegas 

Valley are components of the study. This study has 

been funded by the Federal Transit Administration. 

4.7.2.2 Quantification of Vehicular Emissions in the 

Las Vegas Valley Air Basin and Impacts on Air 

Quality

This ongoing study is coordinated with the SNAQS and 

is funded by the Nevada Department of Motor Vehicles 

under the sponsorship of the CCDCP. The focus of the 

study is development of a vehicle registration 

information data base that is linked to emission 

measurements conducted as part of the SNAQS. This 

data base will allow researchers to draw conclusions on 

the profiles of high-emitting vehicles, their geographic 

concentrations, the effectiveness of the current smog 

check program, and to develop effective control 

strategies for reducing emissions from on-road gasoline 

and diesel vehicles. 

4.7.2.3 Chemical Characterization of PM2.5 in the Las 

Vegas Valley

This ongoing study is coordinated with the SNAQS and 

is funded by the Nevada Department of Motor Vehicles 

under the sponsorship of the CCDCP. The objectives of 

this study are characterization of the chemical 

composition of PM2.5 in the Las Vegas Valley, estimation 

of the contribution of major source types to PM2.5

concentrations and urban haze, the contributions of 

Continuing Research 

in Clark County 
 4-122 

transported constituents to PM2.5 concentrations and 

urban haze, and the fraction of dust in PM2.5 and PM10

particulate concentrations. PM2.5 samples will be taken 

at an urban and background site every third day for a 

one-year period. PM10 samples will be taken every sixth 

day from a co-located PM10 sampler at the urban site. 

4.8 CLARK COUNTY AIR QUALITY SIP 

COMMITMENTS 

4.8.1 Commitment For Additional Staffing Levels 

and Enhanced Enforcement Efforts 

The AQD currently employs one enforcement 

supervisor, seven enforcement officers, one senior 

administrative clerk, one administrative clerk, and one 

 administrative secretary to enforce former Section 17 

(Dust Control Permit for Construction) and Section 41 

(Fugitive Dust). The AQD has committed to hiring 15 

additional staff to implement and enforce Sections 90, 

91, 92, 93, and 94 with Resolution 02-00, dated July 27, 

2000.41 A new compliance team, titled Dust Mitigation 

and Prevention (DMAP), has been formed and will have 

ten new positions to focus on Sections 90, 91, 92, and 

93 of the Air Quality Regulations. These positions will 

include a supervisor, clerical, secretarial support, field 

enforcement, and one half-time attorney. An additional 

five new staff members will be hired to augment the 

existing construction activity program, as the newly 

adopted Section 94 supplements and strengthens the 

existing Sections 17 and 41 of the Air Quality 

Regulations. The five new positions for the construction 

program will include one person to handle additional 

construction permit processing, an additional clerical 

position, and three additional enforcement officers. 

Costs incurred for the additional personnel and 

equipment (but not including phones, computers, and 

certain administrative costs) are estimated to be 

$780,000 for the first year. Targeted funding sources 

are a dust control permit fee increase of $15 per acre 

(from $90 per acre to $105), redirecting funding from the 

PM10 Emission Control Research Account, and 

increased funding from the Clark County general fund. 

The dust control permit fee was approved by the 

 

41 See Appendix H 

Additional 

Enforcement Staff Will 

Be Hired 

An Increase in Dust 

Control Permit Fees 

Will Help Defray the 

Costs of Additional 

Staff 
 4-123 

Clark County Health District Board of Health on 

December 14, 2000. The CCHD is currently seeking 

office space for the new staff positions. Ramp-up of 

additional staff will occur during 2001, and all new 

positions will be filled by December 31, 2001. The 

control measure effectiveness values utilized in this SIP 

are predicated on this schedule. 

Violations of the Air Quality Regulations are heard by 

hearing officers who can make findings of violation and 

assess penalties. The AQD currently has five Board of 

Health-appointed hearing officers. Implementation of 

the new regulations in conjunction with these enhanced 

enforcement efforts may result in the need for additional 

hearing officers. 

The AQD will identify and prioritize areas for inspection. 

The initial focus areas for inspection will be areas of 

Hydrographic Basin 212 characterized as having a high 

degree of soil disturbance. 

4.8.2 Clark County Research Commitments 

4.8.2.1 Participation in Funding Dust Suppressant 

Multi-Media Studies 

Clark County Health District will participate in funding 

and coordination of research to determine the potential 

for multi-media adverse environmental impacts from the 

long-term use of dust suppressant products. UNLV has 

recently obtained funding from local agencies for 

conducting a field study to evaluate potential long-term 

water quality impacts from the use of several classes of 

dust suppressant products. The study will evaluate 

impacts to both surface water runoff from treated areas 

and water that has percolated through a treated area. 

The AQD has provided partial funding for this study and 

AQD and CCDCP staff are assisting UNLV in 

coordinating this work with research planned by the 

U. S. EPA. The results of the study are anticipated to 

be available before the end of 2003. 

4.8.2.2 Commitment to Conduct a PM10 Saturation 

Study

Clark County Department of Comprehensive Planning 

will conduct a PM10 saturation study that will begin in 

Dust Suppressants 

and Their Effects Will 

Be Studied 
 4-124 

2004 and be completed by the 2006 RFP Plan deadline. 

The focus of the study will be on neighborhood impacts 

of major sources, particulate concentrations in 

geographic locations not well covered by the current 

monitoring network due to growth within the valley, and 

inter-basin intra-basin transport during high wind events. 

The study will be conducted in later years to measure 

the impacts of growth in future years. In addition to the 

primary objectives of the study, the results will be 

utilized in future evaluations of the National Ambient 

Monitoring Network (NAMS), State and Local Air Quality 

Monitoring Network (SLAMS), and Special Purpose 

Location (SPL) monitoring network. 

4.8.2.3 Commitment to Develop An Improved 

Inventory of Unpaved Roads

Clark County Department of Comprehensive Planning 

will develop an improved inventory of unpaved roads. 

The inventory for publicly maintained roads will be 

developed by Clark County Public Works, City of North 

Las Vegas Public Works, City of Las Vegas Public 

Works, and City of Henderson Public Works 

departments and will be completed by the first quarter of 

2002. The inventory of unpaved private roads will be 

completed by CCDCP using either satellite data or 

aerial photography by March of 2003. 

4.8.2.4 Commitment to Develop An Improved 

Disturbed Vacant Land and Construction Inventory

Clark County Department of Comprehensive Planning 

will pursue development of an improved inventory of 

disturbed vacant land and construction activities. The 

vacant land inventory will be developed using satellite 

data and ground truthing. It will be completed by June 

of 2003. The construction activities inventory will be 

developed using the AQD dust permitting data base, the 

Clark County’s GIS system and aerial photographs. 

The construction inventory update will be completed by 

the end of 2002. 

4.8.2.5 Commitment to Develop Improved Emission 

Factors for Native Desert and Disturbed Areas 

The emission factors for native desert used in the PM10

plan were developed by UNLV based on data 

developed with the UNLV wind tunnel. When these 

Commitments To 

Improve Emission 

Inventories 
 4-125 

test were conducted, the U. S. EPA test for soil surface 

characterization had not been developed. Because 

both undisturbed native desert and disturbed areas 

account for a major part of the PM10 emissions that are 

generated during high wind conditions, a refinement of 

the emission factors for these sources is warranted. 

Clark County Department of Comprehensive Planning 

anticipates moving forward with additional studies to 

develop refined emission factors in 2003, with 

completion of the studies expected by the end of 2005. 

4.8.2.6 Commitment to Track Silt Loadings on Paved 

Roads 

Clark County Department of Comprehensive Planning 

will conduct additional measurements of silt loadings on 

paved roads in order to update the paved roads 

emission inventory and evaluate the effectiveness of 

control measures for reducing silt loading on paved 

roads. Silt loading measurements will begin in the 

fourth quarter of 2001 and be conducted quarterly 

though June of 2006. 

4.8.2.7 Commitment to Establish Test Methods for 

Section 94

If an acceptable test method has not been developed 

and adopted into Section 94 by September 1, 2001, 

Clark County will fund additional research up to 

$100,000 to develop an acceptable test method. It is 

Clark County’s intention that a contractor will be 

selected by November 1, 2001. If a test method that is 

acceptable to U. S. EPA under its BACM and 

enforceability criteria has not been incorporated into 

Section 94 by November 1, 2002, the opacity test 

method for unpaved roads in Section 91 will be 

presented to the governing board for adoption in 

December of 2002 for all non-process, intermittent 

construction site fugitive dust generating activities. 

4.8.2.8 Commitment to Update Emission Inventories

Clark County will revise the entire PM10 emission 

inventories for the attainment year in 2003 and 2006 to 

coincide with the Reasonable Further Progress reports. 

If the emission inventories are significantly different than 

in this SIP, particularly if the differences would affect the 

attainment demonstration, the SIP will be adjusted to

Commitment to 

Research 

Development of a 

Better Construction 

Activities Test Method 
 4-126 

reflect the revised PM10 emission inventories. If the SIP 

inventory requires adjustment, it will be resubmitted for 

approval to U. S. EPA with the Reasonable Further 

Progress/milestone reports that include revising 

conformity budgets and re-evaluation of control 

measures if necessary. The existing approved SIP and 

conformity budgets will remain in place until such time 

as a new SIP is approved. 

4.8.2.9 Commitment to Revise Air Quality 

Regulations

The following proposed language for revision to the Air 

Quality Regulations will move forward in the rule 

development and adoption process, with rule revisions 

to be brought to the Clark County Health District Board 

of Health for approval at the regularly scheduled 

meeting in August of 2001. 

Section 90.2.1.3 –Dust Mitigation Plan Required: 

Owners AND/OR OPERATORS of OPEN AREAS AND 

VACANT LOTS having a cumulative area of 10,000 

acres or greater must submit a dust mitigation 

plan to the Air Quality Division for approval by 

January 1, 2002 in a format prescribed by the 

CONTROL OFFICER. 

Section 92.2.1.1 Revised Section: 

No UNPAVED PARKING LOTS may be constructed 

after the adoption of this Subsection except as 

provided in Subsection 92.2.1.1 (a) and (b) 

below: 

(a) The requirements of Subsection 

92.2.1.1 shall not be applicable to 

parking lots for rural public facilities 

such as trailheads, campgrounds, 

and similar facilities where paved 

parking lots would conflict with the 

rural nature of these facilities; and 

(b) The unpaved parking lot is 

stabilized in accordance with 

Subsection 92.2.1.2 (b) through (d) 

Revisions to Air 

Quality 

Regulations Moving 

Forward in The Rule 

Process