# [

COUNTYAIRQUALITYZZEMENZRD
AIRQUALITYREGULATIONS

SECTION91

-

### FUGITIVE DUSTFROM UNPAVEDROADS, UNPAVED ALLEYS, ANDUNPAVED EASEMENTROADS

91 .1 FuGITIvE DUST From Unpaved Roads, Unpaved Alleys, and Unpaved EASEMENT Roads
91.1.1 Purpose: To limit the Emission of PARTIcuLATE MATTER into the AMBIENT AIR from unpaved roads, unpaved alleys, unpaved ROAD EASEMENTS and unpaved access roads for utilities and railroads.
91.1.2 Applicability: The provisions of this Regulation shall apply to unpaved roads, which includes unpaved alleys, unpaved ROAD EASEMENTS and unpaved access roads forutilities and railroads which are located in the PMio N0N-ATIAINMENT AREA (HYDR0GRAPHIc BASIN 212) and the Apex Valley (HYDR0GRAPHIc BAsINs 216 and 21 7). Nothing in Subsections 91 .1 through 91 .3 ofthese Regulations shall be construed to prevent enforcement of Section 40 (Prohibition of NUISANCE Conditions) ofthese Regulations. The provisions ofthis Regulation shall not apply to non-commercial and non-institutional private driveways and shall not apply to horse trails, hiking paths, bicycle paths, or other similar paths that have been officially designated by a governing body for exclusive use for purposes other than travel by motor vehicles. The provisions of this Regulation shall not apply to STATIONARY SOURCES as defined in Section 0, except that these control measures shall be considered as part ofa BACTdetermination.
91 .1 .3 Effective Date OfThis Regulation:
91.1.3.1 Regulations 91.1 through 91.3 shall be effective in HYDR0GRAPHIc BASIN 212 ontheir adoption bythe District Board of Health of Clark County on June 22, 2000.
91.1.3.2 Regulations 91.1 through 91.3 shall be effective in HYDR0GRAPH1c BAsINs 216 and 217 on April 1, 2002.
91 .2 Requirements:

Revised 11/20/01 91-1 

### AirQualityRegulations CCAQMB, 500c3randCentralPkwy, LV89155 

# I91 .2.1 Unpaved Roads: An OWNER AND/OR OPERATOR of an unpaved road in the PMio NON-ATTAINMENT AREA, shall implement one of the CONTROL MEASURES setforth in Subsection 91 .2.1 .3 ofthis Regulation, except as set forth in Subsection 91 .2.1 .1 ofthis Regulation. Forthe purpose of this Regulation, the CONTROL MEASURES shall be considered effectively implemented when the unpaved roadway complies with the stabilization standards set forth in Subsection 91 .2.1 .4 of this Regulation. Advisory Notice: In order to conserve water to the greatest extent practicable, the use of RECLAIMED WATER is highly encouraged.
91 .2.1.1 ImplementationOfCONTROLMEASURESForExisting Unpaved Roads:

91 .2.1 .1 .1 OWNERS AND/OR OPERATORS of existing unpaved roads that were constructed prior to June 22, 2000 in HYDROGRAPHIC BASIN 21 2 shall implement one of the CONTROL MEASURES set 

### forth Subsection 91 .2.1 .3 ofthis Regulation accordingtothefollowing schedule:
(a) CONTROL MEASURES shall be implemented for one third (1/3) of the total miles of unpaved roads having vehicular traffic of 150 vehicles or more per day in accordance with Subsection 91.2.1.3 (CONTROL MEASURES) of this Regulation by June 1, 2001.
91 CONTROLMEASURES shall be implemented for two thirds (2/3) of the total miles of unpaved roads having vehicular traffic of 150 vehicles or more per day in accordance with Subsection 91.2.1.3 (CONTRoL MEAsuREs) of this Regulation by June 1, 2002.
(c) CONTROL MEASURES shall be implemented for all unpaved roads having vehicular traffic of 150 vehicles or more per day in accordance with Subsection 91.2.1.3 (CONTRoL MEASURES) of this Regulation byJune 1, 2003. (d) CONTROL MEASURES set forth in Subsection 91 .2.1 .3 shall be implemented for existing unpaved roads on which vehicular traffic is equal to or greater than 150 vehicles per day that develops after June 1, 2003. CONTROL MEASURES shall be implemented within 365 calendar days following the initial discovery that vehicular traffic equals or exceeds 150 vehicles per day and that the road surface does not comply with the stabilization standards set forth in Subsection 91.2.1.4 of this Regulation. The CONTROL OFFIcER may require short-term

Revised 11/20/01 91-2 

### AirQualifyRegulations CCAQMB, 500GrandCentralPkwy,LV89155

# 3

stabilization of any unpaved road subject to Subsection 91.2.1.1(d). (e) Non-federal Requirement: CONTROL MEASURES set forth in Subsection 91 .2.1 .3 shall be implemented for existing unpaved roads having vehicular traffic of less than 150 vehicles per day within 365 calendardays following the initial discovery thatthe road surface does not comply with the stabilization standards set forth in Section 91.2.1.4 of this Regulation. The requirements of this Subsection (91.2.1.1 (e) shall not constitute applicable State Implementation Plan requirements pursuant to Section 189 of the federal Clean Air Act. The CONTROL OFFICER may require short-term stabilization of any unpaved road subject to Subsection 91 .2.1 .1 (e)). For the purpose of this Subsection, the CONTROL MEASURES shall be considered effectively implemented when the unpaved road complies withthe stabilization standards setforth in Subsection 91.2.1.4ofthis Regulation.
91.2.1.1.2 OwNERS AND/OR OPERATORS of existing unpaved roads that were constructed prior to April 1, 2002 in HYDR0GRAPHIC BASINS 216 and 217_shall implement one of the CONTROL MEASURES set forth Subsection 91.2.1.3 of this Regulation according to the following schedule: (a) CoNTROL MEASURES shall be implemented for one third 

### (113) of the total miles ofunpaved roads having vehiculartraffic of 150 vehicles or more per day in accordance with Subsection 91.2.1 .3 (CoNTRoL MEASURES) of this Regulation by April 1, 2003. (b) CoNTROLMEASURES shall be implementedfortwothirds (2/3) of thetotal miles ofunpaved roads having vehiculartraffic of 150 vehicles ormoreperdayin accordance with Subsection 91 .2.1 .3 (CONTROLMEASURES) ofthis Regulation byApril 1, 2004. (c) CONTROL MEASURES shall be implemented for all unpaved roads having vehicular traffic of 150 vehicles or more per day in accordance with Subsection 91.2.1 .3 (CoNTROL MEASURES) of this RegulationbyApril 1, 2005. (d) CoNTRoL MEASURES set forth in Subsection 91 .2.1 .3 shall be implemented for existing unpaved roads on which vehicular

Revised 11/20/01 91-3 

### AirQualityRegulations CCAQMB, 500GrandCentralPkwy, LV89155

# i traffic is equal to or greater than 150 vehicles per day that develops after April 1, 2005. CoNTRoL MEASURES shall be implemented within 365 calendar days following the initial discovery that vehicular traffic equals or exceeds 150 vehicles per day and that the road surface does not comply with the stabilization standards set forth in Subsection 91 .2.1 .4 of this Regulation. The CONTRoL OFFICER may require short-term stabilization of any unpaved road subject to Subsection 91.2.1.1(d). Ce) Non-federal Requirement: CONTROL MEASURES set forth in Subsection 91 .2.1.3 shall be implemented for existing unpaved roads having vehiculartraffic ofless than 150 vehicles perday within 365 calendardays following the initial discovery thatthe road surface does not comply with the stabilization standards set forth in Section 91 .2.1 .4 of this Regulation. The requirements of this Subsection (91.2.1.1 Ce) shall not constitute applicable State Implementation Plan requirements pursuant to Section 189 of the federal Clean Air Act. The CONTROL OFFICER may require short-term stabilization of any unpaved road subject to Subsection 91 .2.1 .1 (e)). For the purpose of this Subsection, the CONTRoL MEAsuREs shall be considered effectively implemented when the unpaved road complies with the stabilization standards setforth in Subsection 91.2.1.4ofthis Regulation.
91.2.1.2 No unpavedroads oralleys maybeconstructedinpublicthoroughfares in HYDROGRAPHIC BASIN 212 after June 22, 2000, or in HYDR0GRAPHIC BAsINs 216 and 217 afterApril 1,2002, unless the unpaved road is an interim component of an active paving project.
91.2.1.3 CoNTROLMEASURES: (a) PAVE, or (b) Apply DUST PALLIATIVES, in compliance with the stabilization standards setforthin Subsection 91 .2.1 .4 ofthis Regulation, or Cc) Apply and maintain and alternative CoNTROL MEASURE approved in writing by the CONTROL OFFICER and the Region IX Administrator ofthe EPA.
91.2.1.4 Stabilization Standards: For the purpose of this rule, CONTROL MEASURES shall be considered effectively implemented when

Revised 11120101 91-4 AirQualityRegulations CCAOMB, 500GrandCentralPkwy, LV89155

## f U

. stabilization observations for FUGITIVE Dust EMISSIONS from unpaved roads and unpaved alleys do not exceed 20% OPAcITY and do not equal or exceed 0.33 oz/ft 2 sift loading, or do not exceed 6% silt content, as determinedby Subsection 91 .4.1 ofthese Regulations.

91.3 Record Keeping Requirements
91 .3.1 Record Keeping: Any person subjecttotherequirements ofthis Regulation shall compile and retain records that provide evidence of CONTROL MEASURE application, by indicating type of treatment or CONTROL MEAsuRE, extent of coverage, and date applied. The records and supporting documentation shall be made availableto the CoNTRoL OFFICER within 24hours fromwritten orverbalrequest.
91 .3.2 Records Retention: Copies of the records required by Subsection 91.3.1 (Record Keeping Requirements) of this Regulation shall be retainedforatleastoneyear.
91 .3.3 Reports Required: In addition to complying with the record keeping requirements specified in Subsection 91 .3.1, OwNERs of unpaved roads shall be subject to the requirements set forth in Subsection 91.2.1.1, and shall prepare and submitawrittenreporttothe CONTROL OFFICER documenting compliance with the provisions •of Subsection 91 .2.1 .1. This report shall be prepared for the years 2001, 2002, and 2003 for OwNERs ofunpaved roads in HYDR0GRAPHIC BASIN 212, for the years 2003, 2004, and 2005 for OWNERS of unpaved roads in HYDR0GRAPHIc BASINS 216 and 217, and shall be submitted to the CONTROL OFFICER no later than October first of each yearand shall include:
91 .3.3.1 The total miles ofunpaved roads under thejurisdiction ofthe OWNER and the miles PAVED during the reporting period subject to the requirements of Subsection 91.2.1.1. Miles of PAvING for roads subject to Subsections 91.2.1.1.1(a), 91.2.1.1.1(b), and 91.2.1.1.1(c) mustbe listed separately from paving ofroads found to be subject Subsection 91 .2.1 .1 .1 (d). Miles of PAVING for roads subject to Subsections 91 .2.1 .1 .2(a), 91 .2.1 .1 .2(b), and 91.2.1.1.2(c) must be listed separatelyfrom paving ofroads found to besubjectSubsection 91.2.1.1.2(d).
91 .4 TestMethods
91 .4.1 Stabilization Test Methods For Unpaved Roads And Unpaved Alleys:
Revised11/20/01 91-5 AirQualltyRegulations CCAQMB,500GrandCentralPkwy,LV69155

# I ()i

91.4.1.1 OPACITY Test Method: The purpose of this test method is to estimate the percent OPACITY of FuGITIvE DUST plumes caused by vehicle movementon unpavedroads, unpaved alleys, and unpaved EAsEMENTs. This method can only beconducted by an individual who has received certification as aqualifiedVisibleEMISSIONS Evaluator, (a) Step 1: Stand at least 16.5 feet from the FUGITIVEDUST source in order to provide a clear view of the EMISSIONS with the sun oriented in the 140-degree sector to the back, Following the above requirements, make OPACITY observations so that the line of vision is approximately perpendicular to the dust plume and wind direction. If multiple plumes are involved, do not include more than one plume inthe line of sightatonetime. (b) Step 2: Record the FUGITIVE DUST source location, source type, method of control used, if any, observer’s name, certification data and affiliation, and a sketch of the observer’s position relative to the FUGITIVE DUST source. Also, record the time, estimated distance to the FUGITIVE DusT source location, approximate wind direction, estimated wind speed, description of the sky condition (presence and color of clouds), observer’s position to the FUGITIVEDUST source, and colorofthe plume and type of background on the visible emission observation form both when OPACITYreadings are initiated and completed. (c) Step 3: Make OPACITY observations, to the extent possible, using a contrasting background that is perpendicular to the line of vision. Make OPACITY observations approximately 1 meter above the surface from which the plume is generated. Notethat the observation is to be made at only one visual point upon generation of a plume, as opposed to visually tracking the entire length of a dust plume as it is created along a surface. Make two observations pervehicle, beginning with the firstreading at zero seconds and the second reading at five seconds. The zero-second observation should begin immediately after a plume has been created above the surface involved. Do not look continuously at the plume but, instead, observe the plume briefly atzero seconds andthen again atfive seconds. (d) Step 4: Record the OPACITY observations to the nearest 5% on an observational record sheet. Each momentary observation recorded represents the average OPACITY of EMissioNs for a 5-second period. While it is not required by the test method, 

### Revised 11/20/01 91-6 

### AirQualityRegulations CCAQMB, 500GrandCentralPkwy, LV89155/(J / EPA recommends thatthe observerestimatethe size ofvehicles which generate dust plumes for which readings are taken (e.g. mid-sizepassengercarorheavy-dutytruck) andtheapproximate speedsthevehicles aretraveling when readings aretaken. (e) Step 5: Repeat Step 3 (Subsection 91 .4.1 .1(c) of this Regulation) and Step 4 (Subsection 91.4.1 .1 (d) of this Regulation) until you have recorded a total of 12 consecutive OPACITY readings. This will occur once six vehicles have driven on the source in your line ofobservation for which you are able to take proper readings. The 12 consecutive readings must be taken within the same period of observation but must not exceed 1 hour. Observations immediately preceding and following interrupted observations can be considered consecutive. (f) Step & Average the 12 OPAcITY readings together. If the average OPAcITY reading equals 20% or lower, the source is in compliance with the OPACITY standard described in Section 91 ofthese Regulations. 91.4.1.2 Silt Content Test Method: The purpose of this test method is to estimate the silt content of the trafficked parts of unpaved roads, unpaved alleys, and unpaved EAsEMENTs. The higher the silt content, the greaterthe amountoffinedustparticles thatareentrained into the atmosphere when cars and trucks drive on unpaved roads, unpaved alleys, and unpaved EASEMENTS. (a) Equipment: (1) A set of sieves with the following openings: 4 millimeters (mm), 2 mm,”l mm, 0.5 mm and 0.25 mm, a lid, and collectorpan (2) A small whiskbroom or paintbrush with stiff bristles and dustpan 1 foot in width (the broom/brush should preferably have one, thin row of bristles no longer than 1 .5 inches inlength) (3) Aspatulawithoutholes (4) A small scale with half ounce increments (e.g., postal/ package scale)

Revised 11/20101 91-7 

### AirQualityRegulations CCAQMB, 500GrandCentralPkkvy, LV89155(5) A shallow, lightweight container (e.g., plastic storage container) (6) A sturdy cardboard box or other rigid object with a level surface (7) Acalculator (8) Cloth gloves (optional for handling metal sieves on hot, sunny days) (9) Sealableplastic bags (ifsending samplesto a laboratory) (10) Apencil/pen and paper (b) Step 1: Look for a routinely traveled surface, as evidenced by tiretracks (onlycollect samples from surfacesthatare not damp due to precipitation or dew). This statement is not meantto be a standard in itselffor dampness where watering is being used
as a CONTROL MEAsuRE. It is only intended to ensure that surface testing is done in a representative manner. Use caution when taking samples to ensure personal safety with respect to passing vehicles. Gently press the edge ofa dustpan (1 foot in width) into the surface four times to mark an area that is 1 square foot. Collect a sample ofloose surface material using a whiskbroom or brush and slowly sweep the material into the dustpan, minimizing escape of dust particles. Use a spatula to lift heavier elements such as gravel. Only collect dirt/gravel to an approximate depth of 3/8 inch or 1 cm in the 1 square foot area. Ifyou reach a hard, underlying subsurface that is greater than 3/8 inch in depth, do notcontinue collecting the sampleby digging into the hard surfacer In other words, you are only collecting a surface sample of loose material down to 1 cm. In order to confirm that samples are collected to 1 cm in depth, a wooden dowel orother similar narrow objectatleastone footin length can be laid horizontally across the survey area while a metric ruleris held perpendiculartothedowel.

• At this point, you can choose to place the sample collected into a plastic bag or container and take it to an independent laboratory for silt content analysis. A reference to the procedure the laboratory is required to follow is attheend ofthis section.

Revised 11/20/01 91-8 

### AirQualityRegulations CCAQMB, 500GrandCentralPkw LV89155(c) Step 2: Place a scale on a level surface. Place a lightweight container on the scale. Zero the scale with the weight of the empty container on it. Transfer the entire sample collected in the dustpan to the container, minimizing escape of dust particles. Weighthe sample andrecord its weight. (d) Step 3: Stack a set of sieves in order according to the size openings specified above, beginning with the largest size opening (4 mm) atthetop. Placea collectorpan underneaththe bottom (0.25 mm) sieve. (a) Step 4: Carefully pour the sample into the sieve stack, minimizing escape of dust particles by slowly brushing material into the stack with a whiskbroom or brush (on windy days, use thetrunk or door ofa car as awind barricade). Coverthe stack with a lid. Lift up the sieve stack and shake it vigorously up, down and sideways foratleast 1 minute. (f) Step 5: Remove the lid from the stack and disassemble each sieve separately, beginning with the top sieve. As you remove each sieve, examine it to make sure that all ofthe material has been sifted to the finest sieve through which it can pass; e.g. material in each sieve (besides the top sieve that captures a range of larger elements) should look the same size. If this is not the case, re-stack the sieves and collector pan, cover the stack with the lid, and shake it again for at least 1 minute (you only need to reassemble the sieve(s) that contain material, which requires further sifting). (g) Step 6: Afterdisassembling the sieves and collectorpan, slowly sweep the material from the collector pan into the empty container originally used to collect and weigh the entire sample. Take care to minimize escape of dust particles. You do not need to do anything withmaterial captured in the sieves; only the collector pan. Weigh the container with the material from thecollectorpan and record its weight. (h) Step 7: If the source is an unpaved road, multiply the resulting weight by 0.38. If the source is an UNPAVED PARKING LOT, multiply the resulting weight by 0.55. The resulting number is the estimated silt loading. Then, divide by the total weight of the sample you recorded earlier in Step 2 (Subsection 91 .4.1.2(c) ofthis Regulation) and multiply by 100 to estimate thepercent siltcontent.
Revised 11/20/01 91-9 

### AirQualityRegulations CCAQM8, 500GrandCentralPkwy, LV89155 

# 7(i) Step 8: Select another two routinely traveled portions of the unpaved road or UNPAVED PARKING LOT and repeat this test method. Once you have calculated the silt loading and percent silt content of the 3 samples collected, average your results together. 

### (j) Step 9: Examine Results. Ifthe average siltloading is less than 0.33 oz/ft 2

, the surface is stable. If the average silt loading is greater than or equal to 0.33 oz/ft 2

, then proceed to examine the average percent silt content. If the source is an unpaved road, unpaved alley, or unpaved EAsEMENT and the average percent silt contentis 6% or less, the surface is stable. Ifyour field test results are within 2% of the standard (for example, 4%-8% silt content on an unpaved road, alley, or EASEMENT), it is recommended that you collect 3 additional samples from the source according to Step 1 (Subsection 91 .4.1 .2(b) of this Regulation) and take them to an independent laboratory for silt content analysis. (k) Independent Laboratory Analysis: You may choose to collect 3 samples from the source, according to Step 1 (Subsection 91 .4.1 .2(b) of this Regulation), and send them to an independent laboratory for silt content analysis rather than conductthe sieve field procedure. If so, the test method the laboratory is requiredto useis: “Procedures ForLaboratoryAnalysis OfSurface/Bulk Loading Samples”, (Fifth Edition, VolumeI, Appendix C.2.3 “SiltAnalysis’, 1995), AP-42, Office ofAir Quality Planning & Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina

Revised 11/20/01 91-10 

### AirQualityRegulations CCAQMB, 500GrandCentralPkwy, LV89155