EPA SIP Enforceability Statement

1. APPLICABILITY

a. What sources are being regulated? 

Appendix C describes procedures for test methods associated with Rule 310 

(Fugitive Dust). The provisions of Rule 310 apply to all dust-generating operations. 

Dust-generating operations include: any activity capable of generating fugitive dust, 

including but not limited to, land clearing, earthmoving, weed abatement by discing 

or blading, excavating, construction, demolition, bulk material handling, storage 

and/or transporting operations, vehicle use and movement, the operation of any 

outdoor equipment, or unpaved parking lots. For the purpose of this rule, landscape 

maintenance and playing on or maintaining a field used for non-motorized sports 

shall not be considered a dust-generating operation. However, landscape 

maintenance shall not include grading, trenching, or any other mechanized surface 

disturbing activities performed to establish initial landscapes or to redesign existing 

landscapes. The completeness checklist for Rule 310 is in a separate document. 

b. What exemptions are provided? 

Appendix C describes procedures for test methods associated with Rule 310 

(Fugitive Dust). The provisions of this rule shall not apply to normal farm cultural 

practices according to Arizona Revised Statutes (A.R.S.) § 49-457 and A.R.S. § 

49-504.4. The provisions of this rule shall not apply to the following nontraditional sources of fugitive dust that are located at sources that do not require 

any permit under these rules. These non-traditional sources of fugitive dust are 

subject to the standards and/or requirements described in Rule 310.01-Fugitive 

Dust From Non-Traditional Sources of Fugitive Dust of these rules. a. Vehicle use 

in open areas and vacant lots. b. Open areas and vacant lots. c. Unpaved parking 

lots. d. Unpaved roadways (including alleys). e. Livestock activities. f. Erosioncaused deposition of bulk materials onto paved surfaces. g. Easements, rights-ofway, and access roads for utilities (transmission of electricity, natural gas, oil, 

water, and gas). The provisions of this rule shall not apply to emergency activities 

that may disturb the soil conducted by any utility or government agency in order 

to prevent public injury or to restore critical utilities to functional status. The 

completeness checklist for Rule 310 is in a separate document. 

c. What are the units of compliance? 

The units of compliance are: 

Opacity Test Method. The purpose of this test method is to estimate the percent 

opacity of fugitive dust plumes caused by vehicle movement on unpaved roads and 

unpaved parking lots. This method can only be conducted by an individual who has 

received certification as a qualified observer. Units are in percentages. 

Soil Crust Determination(The Drop Ball Test). The purpose of this test method is to 

estimate the silt content of the trafficked parts of the unpaved roads and unpaved 

parking lots. Units are in centimeters per second. 
Determination of Threshold Friction Velocity (TFV). The purpose of this test 

method is to determine whether an open area or a vacant lot has a stabilized surface. 

Units are in centimeters per second. 

Determination of Flat Vegetative Cover. The purpose of this test method is to 

determine whether an open area or a vacant lot has a stabilized surface. Units are in 

square meters or square inches. 

Determination of Standing Vegetative Cover. The purpose of this test method is to 

determine whether an open area or a vacant lot has a stabilized surface. Units are in 

square meters or square inches. 

Rock Test Method. The purpose of this test method is to examine the windresistance effects of rocks and other non-erodible elements on disturbed surfaces. 

Units are in percentages of rock cover. 

Visual Opacity Determination of Emissions From Dust-Generating Operations. The 

purpose of this test method is to determine opacity of fugitive dust plumes from 

dust-generating operations. Units are in percentages. 

Visual Opacity Determination of Emissions from Livestock Activities - Corrals, 

Pens and Arenas. The purpose of this test method is to determine opacity of fugitive 

dust plumes from livestock activities - corrals, pens and arenas. Units are in 

percentages. 

d. Is bubbling or averaging of any type allowed? 

No. 

e. If there is a redesignation, will this change the emission limitations? 

No. 

2. COMPLIANCE DATES

a. What is the compliance date? 

The compliance date is the date of the appendix adoption – March 26, 2008. 

b. What is the attainment date? 

Particulates attainment date: December 31, 2006 

CO attainment date: December 31, 2000 

Ozone attainment date: November 15, 1999 

3. SPECIFICITY OF CONDUCT 

a. What test method is required? 

Appendix C describes procedures for the following test methods associated with 

Rule 310 (Fugitive Dust): 

Unpaved roads and unpaved parking lots opacity test method. 
Silt content test method. 

Stabilization limitations for open areas and vacant lots. 

Soil Crust Determination. 

Determination of Threshold Friction Velocity. 

Determination of Flat Vegetative Cover. 

Determination of Standing Vegetative Cover. 

Rock Test Method. 

Visual Opacity determination of emissions from dust-generating operations for 

fugitive dust emissions. 

Visual Opacity determination of emissions from livestock activities - Corrals, Pens 

and Arenas. 

b. What is the averaging time in the compliance test method? 

Appendix C, Section 2 (Test Methods for Stabilization) states: 

Unpaved Roads and Unpaved Parking Lots Opacity Test Method: The purpose of 

this test method is to estimate the percent opacity of fugitive dust plumes caused by 

vehicle movement on unpaved roads and unpaved parking lots. Make 2 

observations per vehicle, beginning with the first reading 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. Record a 

total of 12 consecutive opacity readings. This will occur once 6 vehicles have 

driven on the source in the line of observation for which readings are taken. The 12 

consecutive readings must be taken within the same period of observation but must 

not exceed 1 hour. 

Silt Content Test Method: The purpose of this test method is to estimate the silt 

content of the trafficked parts of unpaved roads and unpaved parking lots. The 

higher the silt content, the more fine dust particles that are released when cars and 

trucks drive on unpaved roads and unpaved parking lots. 

Stabilization Limitations for Open Areas and Vacant Lots: The purpose of this test 

method is to determine whether an open area or a vacant lot has a stabilized surface. 

Should a disturbed open area or vacant lot contain more than one type of 

disturbance, soil, vegetation, or other characteristics, which are visibly 

distinguishable, test each representative surface separately for stability, in an area 

that represents a random portion of the overall disturbed conditions of the site, 

according to the appropriate test methods listed below. 

Soil Crust Determination 

Determination of threshold friction velocity (TFV) 

Determination of flat vegetative cover 
Determination of standing vegetative cover 

Rock test method 

Appendix C, Section 3 (Visual Opacity Determination of Emissions From DustGenerating Operations) states: 

For Fugitive Dust Emissions: These procedures are applicable for the determination 

of the opacity of fugitive dust emissions by a qualified observer. Make opacity 

observations, to the extent possible, using a contrasting background that is 

perpendicular to the line of sight. For storage piles, make opacity observations 

approximately 1 meter above the surface from which the plume is generated. The 

initial observations should begin immediately after a plume has been created above 

the surface involved. Observe the plume momentarily at 15-second intervals. For 

fugitive dust from earthmoving equipment, make opacity observations 

approximately 1 meter above the mechanical equipment generating the plume. 

For Non-Continuous Dust Plumes Caused by Activities Including Bulk Material 

Loading/Unloading, Non-Conveyorized Screening, or Trenching With Backhoes:

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 in the line of sight at one time. Record the distance 

from the equipment or path that is the identified initial fallout zone. Opacity 

readings should be taken at the maximum point of the entrained fugitive dust plume 

that is located outside the initial fallout zone. Make 2 observations per discrete 

activity, beginning with the first reading at zero seconds and the second reading at 5 

seconds. The zero-second observation should begin immediately after a plume has 

been created above the surface involved. Observe the plume briefly at zero seconds 

and then again at 5 seconds. Each momentary observation recorded represents the 

average opacity of emissions for a 5-second period. Repeat observations until at 

least a total of 12 consecutive opacity readings have been recorded. The 12 

consecutive readings must be take within the same period of observations but must 

not exceed 1 hour. 

For Continuous Dust Plumes Caused by Equipment and Activities Including 

Graders, Trechers, Paddlewheels, Blades, Clearing, Leveling, and Raking:

Evaluate the dust plume generation and determine if the observations will be 

made from a single plume or from multiple related plumes. If there are multiple 

related sources or multiple related points of emissions of dust from a particular 

activity or multiple pieces of equipment operating in a confined area, opacity 

readings should be taken at the densest point within the discrete length of 

equipment travel path within the 140° sector to the back. Record the distance 

from the equipment or path that is identified as the initial fallout zone. Opacity 

readings should be taken at the maximum point of the entrained fugitive dust 

plume that is located outside the initial fallout zone. Observations will be made 

every 10 seconds until at least 12 readings have been recorded. Observe the plume 

momentarily at 10-second intervals. Average 12 consecutive opacity readings 

together. If the average opacity reading equals 20% or lower, the dust-generating 
operation is in compliance with the opacity standard described in Rule 310 

(Fugitive Dust). 

4. RECORDKEEPING 

a. What records are required to determine compliance? 

Records required to determine compliance include: 

Appendix C, Section 2 (Test Methods for Stabilization) states: 

Unpaved Roads and Unpaved Parking Lots Opacity Test Method: The fugitive dust 

source location, source type, method of control used, observer's name, certification 

data and affiliation, a sketch of the observer's position relative to the fugitive dust 

source, 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 fugitive dust source, and 

color of the plume and type of background on the visible emission observation from 

both when opacity readings are initiated and completed. 

Silt Content Test Method: Weigh the container with the material from the collector 

pan and record its weight. 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 recorded earlier and multiply by 100 to estimate the 

percent silt content. Select another two routinely traveled portions of the unpaved 

road or unpaved parking lot and repeat this test method. Once the silt loading and 

percent silt content of the 3 samples have been collected and calculated, average 

the results together. If the average silt loading is less than 0.33 oz/ft2, the surface 

is stable. If the average silt loading is greater than or equal to 0.33 oz/ft2, then 

examine the average percent silt content. If the source is an unpaved road and the 

average percent silt content is 6% or less, the surface is stable. If the source is an 

unpaved parking lot and the average percent silt content is 8% or less, the surface 

is stable. If field test results are within 2% of the standard (for example, 4%-8% 

silt content on an unpaved road), it is recommended that 3 additional samples 

from the source be taken to an independent laboratory for silt content analysis. 

Stabilization Limitations for Open Areas and Vacant Lots: 

Soil crust determination: Where a visible crust exists, drop a steel ball with a 

diameter of 15.9 millimeters (0.625 inches) and a mass ranging from 16-17 grams 

from a distance of one foot directly above (at a 90° angle perpendicular to) the 

soil surface. Drop the ball three times within a survey area that measures 1 foot by 

1 foot and that represents a random portion of the overall disturbed conditions of 

the site. The survey area shall be considered to have passed the Soil Crust 

Determination Test if at least two out of the three times that the ball was dropped, 

the results met the criteria in subsection 2.3.2 of this appendix. Select at least two 

other survey areas that represent a random portion of the overall disturbed 

conditions of the site, and repeat this procedure. If the results meet the criteria of 

subsection 2.3.2 of this appendix for all of the survey areas tested, then the site 
shall be considered to have passed the Soil Crust Determination Test and shall be 

considered sufficiently crusted. Repeat the visible crust test as often as necessary 

on each random portion of the overall conditions of the site for an accurate 

assessment. 

Determination of threshold friction velocity (TFV): Estimate TFV for the sieve 

catch with the greatest volume using Table 1 of this appendix, which provides a 

correlation between sieve opening size and TFV. Collect at least three soil 

samples which represent random portions of the overall conditions of the site, 

repeat the above TFV test method for each sample and average the resulting TFVs 

together to determine the TFV uncorrected for non-erodible elements. Select a 

survey area of 1 meter by 1 meter that represents a random portion of the overall 

conditions of the site. Where many non-erodible elements lie within the survey 

area, separate the non-erodible elements into groups according to size. For each 

group, calculate the overhead area for the non-erodible elements. Repeat this 

procedure on an additional two distinct survey areas that represent a random 

portion of the overall conditions of the site and average the results. Identify the 

correction factor for the percent cover of non-erodible elements. Multiply the 

TFV by the corresponding correction factor to calculate the TFV corrected for 

non-erodible elements. 

Determination of flat vegetative cover: Pinpoint an area the size of a 3/32 inch 

diameter brazing rod or wooden dowel centered above each 1 foot interval mark 

along one edge of the tape. Count the number of times that flat vegetation lies 

directly underneath the pinpointed area at 1 foot intervals. Consistently observe 

the underlying surface from a 90° angle directly above each pinpoint on one side 

of the tape. Do not count the underlying surface as vegetated if any portion of the 

pinpoint extends beyond the edge of the vegetation underneath in any direction. If 

clumps of vegetation or vegetative debris lie underneath the pinpointed area, 

count the surface as vegetated, unless bare soil is visible directly below the 

pinpointed area. When 100 observations have been made, add together the 

number of times a surface was counted as vegetated. This total represents the 

percent of flat vegetation cover (e.g., if 35 positive counts were made, then 

vegetation cover is 35%). If the survey area that represents a random portion of 

the overall conditions of the site is too small for 100 observations, make as many 

observations as possible. Then multiply the count of vegetated surface areas by 

the appropriate conversion factor to obtain percent cover. For example, if 

vegetation was counted 20 times within a total of 50 observations, divide 20 by 50 

and multiply by 100 to obtain a flat vegetation cover of 40%. Conduct the line 

transect test method an additional two times on areas that represent a random 

portion of the overall conditions of the site and average results. 

Determination of standing vegetative cover: Select a survey area that represents a 

random portion of the overall conditions of the site that is the shape of a square 

with sides equal to at least 10 times the average height of the vegetative 

structures. For smaller standing vegetation, select a survey area of three feet by 

three feet. Count the number of standing vegetative structures within the survey 
area. Count vegetation, which grows in clumps as a single unit. Where different 

types of vegetation exist and/or vegetation of different height and width exists, 

separate the vegetative structures with similar dimensions into groups. Count the 

number of vegetative structures in each group within the survey area. Select an 

individual structure within each group that represents the average height and 

width of the vegetation in the group. If the structure is dense (e.g., when looking 

at it vertically from base to top there is little or zero open air space within its 

perimeter), calculate and record its frontal silhouette area, according to Equation 6 

of this appendix. Also, estimate the average height and width of the vegetation if 

the survey area is larger than nine square feet. Otherwise, calculate the frontal 

silhouette area. Then calculate the percent cover of standing vegetation.

Rock test method: Select a 1 meter by 1 meter survey area that represents the 

general rock distribution on the surface. (A 1 meter by 1 meter area is slightly 

greater than a 3 foot by 3 foot area.) Mark-off the survey area by tracing a 

straight, visible line in the dirt along the edge of a measuring tape or by placing 

short ropes, yard sticks, or other straight objects in a square around the survey 

area. Without moving any of the rocks or other elements, examine the survey 

area. Since rocks >3/8 inch (1 cm) in diameter are of interest, measure the 

diameter of some of the smaller rocks to a get a sense for which rocks need to be 

considered. Mentally group the rocks >3/8 inch (1 cm) diameter lying in the 

survey area into small, medium, and large size categories. or, if the rocks are all 

approximately the same size, simply select a rock of average size and typical 

shape. Without removing any of the rocks from the ground, count the number of 

rocks in the survey area in each group and write down the resulting number. 

Without removing rocks, select one or two average-size rocks in each group and 

measure the length and width. Use either metric units or standard units. Using a 

calculator, multiply the length times the width of the rocks to get the average 

dimensions of the rocks in each group. Write down the results for each rock 

group. For each rock group, multiply the average dimensions (length times width) 

by the number of rocks counted in the group. Add the results from each rock 

group to get the total rock area within the survey area. Divide the total rock area 

by two (to get frontal area). Divide the resulting number by the size of the survey 

area (make sure the units of measurement match), and multiply by 100 for percent 

rock cover. For example, the total rock area is 1,400 square centimeters, divide 

1,400 by 2 to get 700. Divide 700 by 10,000 (the survey area is 1 meter by 1 

meter, which is 100 centimeters by 100 centimeters or 10,000 centimeters) and 

multiply by 100. The result is 7% rock cover. If rock measurements are made in 

inches, convert the survey area from meters to inches (1 inch = 2.54 centimeters). 

Select and mark-off two additional survey areas and repeat the procedures. Make 

sure the additional survey areas also represent the general rock distribution on the 

site. Average the percent cover results from all three survey areas to estimate the 

average percent of rock cover. If the average rock cover is greater than or equal to 

10%, the surface is stable. If the average rock cover is less than 10%, the surface 

may or may not be stable. Follow the procedures for the determination of 

threshold friction velocity (TFV) and use the results from the rock test method as 
a correction (i.e., multiplication) factor. If the rock cover is at least 1%, such rock 

cover helps to limit windblown dust. However, depending on the soil’s ability to 

release fine dust particles into the air, the percent rock cover may or may not be 

sufficient enough to stabilize the surface. It is also possible that the soil itself has 

a high enough TFV to be stable without even accounting for rock cover. 

Appendix C, Section 3 (Visual Opacity Determination of Emissions From DustGenerating Operations) states: 

For Fugitive Dust Emissions: The name of the site, fugitive dust source type (i.e., 

pile, material handling (i.e., transfer, loading, sorting)), method of control used, 

observer's name, certification data and affiliation, a sketch of the observer's 

position relative to the fugitive dust source, 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 relative to the fugitive dust source, and color of the plume, and type of 

background on the visible emission observation from when opacity readings are 

initiated and completed. 

For Non-Continuous Dust Plumes Caused by Activities Including Bulk Material

Loading/Unloading, Non-Conveyorized Screening, or Trenching With Backhoes:

(1) location of dust-generating operation, type of operation, type of equipment in 

use and activity, and method of control used, if any; (2) observer's name, 

certification data and affiliation, a sketch of the observer's position relative to the 

dust-generating operation, and observer’s estimated distance and direction to the 

location of the dust-generating operation; (3) time that readings begin, 

approximate wind direction, estimated wind speed, description of the sky 

condition (presence and color of clouds); and (4) color of the plume and type of 

background.

b. In what forms or units must records be kept? 

Appendix C describes procedures for test methods associated with Rule 310 

(Fugitive Dust). Rule 310, Section 502 (Recordkeeping) requires the following: 

Any person who conducts dust-generating operations that require a Dust Control 

Plan shall keep a daily written log recording the actual application or 

implementation of the control measures delineated in the approved Dust Control 

Plan (including records on any street sweeping, water applications, and maintenance 

of trackout control devices, gravel pads, fences, wind barriers, and tarps). 

Any person who conducts dust-generating operations that do not require a Dust 

Control Plan shall compile and retain records (including records on any street 

sweeping, water applications, and maintenance of trackout control devices, gravel 

pads, fences, wind barriers, and tarps) that provide evidence of control measure 

application, by indicating the type of treatment or control measure, extent of 

coverage, and date applied. 
c. On what time basis must records be kept? 

Appendix C describes procedures for test methods associated with Rule 310 

(Fugitive Dust). Rule 310, Section 503 (Records Retention) requires the following: 

Copies of approved Dust Control Plans, control measures implementation records, 

and all supporting documentation shall be retained for at least six months following 

the termination of the dust-generating operation. Copies of approved Dust Control 

Plans, control measures implementation records, and all supporting documentation 

shall be retained for at least 1 year from the date such records were initiated. If a 

person has obtained a Title V Permit and is subject to the requirements of this rule, 

then such person shall retain records required by this rule for at least 5 years from 

the date such records are established.