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Air Sciences 

DRAFT FINAL 

TECHNICAL MEMORANDUM 

REGULATION VIII BACM ANALYSIS 

Prepared for 

Imperial County Air Pollution Control District 

150 South 9th Street 

El Centro, CA. 92243-2801 

Prepared by 

ENVIRON International Corporation 

707 Wilshire Blvd., Suite 4950 

Los Angeles, CA 90017 

October 2005 
Technical Memorandum: Regulation VIII BACM Analysis October 2005

D R A F T F I N A L -i- E N V I R O N 

TABLE OF CONTENTS 

Page

1. INTRODUCTION ...................................................................................................................1 

Background ..............................................................................................................................1 

Best Available Control Measure (BACM) Development and Assessment .............................2 

Purpose.....................................................................................................................................3 

Report Organization.................................................................................................................4 

2. DETERMINATION OF PM10 DE MINIMUS LEVELS........................................................5 

Background ..............................................................................................................................5 

Ambient PM10 and Related Emission Inventories ...................................................................5 

Calculation of DM Levels........................................................................................................7 

Analysis of Major PM10 Stationary Sources............................................................................8 

3. SIGNIFICANT AND DE MINIMIS SOURCE CATEGORIES.............................................9 

Emission Inventory ..................................................................................................................9 

Inventory Discussion .............................................................................................................10 

Conclusions............................................................................................................................15 

4. COMPARATIVE ANALYSIS..............................................................................................17 

Introduction............................................................................................................................17 

Comparative Analysis for Significant Sources ......................................................................18 

Sources on BLM Lands .........................................................................................................18

Comparative Analysis for Sources With Emissions Less Than the DM Level .....................38 

5. IMPACT ANALYSIS............................................................................................................39 

Control Effectiveness and Cost Information..........................................................................39 

PR 801: Construction................................................................................................. 40 

PR 802: Bulk Materials.............................................................................................. 40 

PR 803: Carry-out and Track-out .............................................................................. 41 

PR 804: Open Areas................................................................................................... 41 

PR 805: Paved and Unpaved Roads........................................................................... 42 

PR 806: Conservation Management Practices........................................................... 42 

Cost-Effectiveness .................................................................................................................43 

6. CONCLUSIONS....................................................................................................................58 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

TABLE OF CONTENTS 

(Continued) 

Page

D R A F T F I N A L -ii- E N V I R O N 

APPENDICES 

Appendix A: Technical Memorandum: Latest Revisions of the Windblown Dust Study 

Appendix B: Entrained and Windblown Emissions From Unpaved Roads 

Appendix C: Detailed Comparative Analysis for Significant Sources 

Appendix D: Detailed Comparative Analysis for Sources Below the De Minimis Level 

Appendix E: Draft Regulation VIII Rules and Rule Amendments (dated October 2005) 

Appendix F: BLM Environmental Assessment and Finding of No Significant Impact 

TABLES 

Table 2-1. Annual Average PM10 levels in μg/m3........................................................................6 

Table 2-2. 24-Hour Average PM10 levels in μg/m3 ......................................................................6 

Table 2-3. Annual Average PM10 Emission Inventories for Imperial County in tons/day 

(Only non-zero categories are reported) ......................................................................7 

Table 2-4. Summer Average PM10 Emission Inventories for Imperial County in tons/day 

(Only non-zero categories are reported) ......................................................................7 

Table 3-1. 2004 Annual Average PM10 Emission Inventories for Imperial County in 

tons/day........................................................................................................................9 

Table 3-2. Windblown Emissions from Lands by Month and Annual Average (tons/day)........12 

Table 3-3. Windblown Emissions from Unpaved Roads............................................................13 

Table 3-4. Entrained Unpaved Road Emissions..........................................................................14 

Table 3-5. Imperial County Cattle-Related PM10 Emissions ......................................................15 

Table 3-6. Significant Source Categories of PM10 (2004 emissions in tons/day).......................16 

Table 3-7. De Minimis Source Categories That Emit Greater than 1 ton/day of PM10

(These are NOT significant source categories)..........................................................16 

Table 3-8. De Minimus Source Categories That Emit Less than 1 ton/day of PM10 ..................16 

Table 4-1. Dust Control Source Categories for Sources above the DM Level ...........................18 

Table 4-2. Dust Control Source Categories For Sources Above the DM Level .........................21 

Table 4-3. Dust Control Source Categories For Sources Below the DM Limit..........................38 

Table 5-1. Proposed Regulation VIII Emission Reduction Summary ........................................39 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

TABLE OF CONTENTS 

(Continued) 

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D R A F T F I N A L -iii- E N V I R O N 

Table 5-2. Cost-effectiveness of measures in Proposed Rule 801 – Construction and 

Demolition .................................................................................................................45 

Table 5-3. Cost-effectiveness of measures in Proposed Rule 802 – Bulk Materials ..................46 

Table 5-4. Cost-effectiveness of measures in Proposed Rule 803 – Track-out and Carry-out ...47 

Table 5-5. Cost-effectiveness of measures in Proposed Rule 804 – Open Areas .......................48 

Table 5-6. Cost-effectiveness of measures in Proposed Rule 805 – Paved and Unpaved 

Roads..........................................................................................................................49 

Table 5-7. Cost-effectiveness of measures in Proposed Rule 806 – Conservation 

Management Practices ...............................................................................................51 

Table 5-8 Senate Bill 656 Measures Not in the Proposed Regulation VIII Amended Rules.....52 

FIGURES 

Figure 1-1: Imperial County .........................................................................................................1 

Figure 3-1: Land Use and Land Classification Categories in Imperial County .........................11 
Technical Memorandum: Regulation VIII BACM Analysis October 2005

D R A F T F I N A L -iv- E N V I R O N 

ABBREVIATIONS AND ACRONYMS 

ADVT Average daily vehicle trips 

BLM U.S. Department of Interior Bureau of Land Management 

BMP Best Management Practice (agriculture) 

BP Border Patrol 

CAA Federal Clean Air Act 

CARB California Air Resources Board 

CMP Conservation Management Practice (agriculture) 

IC Imperial County 

ICAPCD Imperial County Air Pollution Control District 

IID Imperial Irrigation District 

NAAQS National Ambient Air Quality Standards 

NEPA National Environmental Policy Act 

PM particulate matter 

PM10 particulate mater less than 10 μm in aerodynamic diameter 

SCAQMD South Coast Air Quality Management District 

SIP State Implementation Plan 

SJV San Joaquin Valley 

SJVAPCD San Joaquin Valley Unified Air Pollution Control District 

TSP total suspended particulates (less than 30 ∝m in aerodynamic diameter) 

USEPA United States Environmental Protection Agency 

VDT Vehicle daily trips 

μg/m3

 microgram per cubic meter 

μm micron or micrometer 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

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1. INTRODUCTION 

Background 

Imperial County is located in the southeastern portion of California and borders Mexicali, Mexico. 

The climate is hot and dry, ranging from lows in the mid 30's in January to highs of 110°F+ in July 

and August (mean annual temperatures: low-55.0°F; of high-89.6°F), with little moisture (average 

annual rainfall: 2.92 inches; 25 percent average relative humidity). Imperial County extends over 

4,597 square miles, bordering Mexico to the south, Riverside County to the north, San Diego 

County to the west, and the State of Arizona to the east. The terrain varies from 235 feet below sea 

level at the Salton Sea to 4,548 feet above sea level at Blue Angel Peak. The population of all of 

Imperial County is about 149,300 people. The principal industries are farming and retail trade. 

Most of the population, farming, and retail trade exists in a band of land on average less than 1/4th 

the width of the county that stretches from the south shore of the Salton Sea to the Mexican border, 

where road network is densest, as shown in Figure 1. 

Figure 1-1: Imperial County 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

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Much of the rest of Imperial County is desert or barren areas that are sparsely populated or 

unpopulated. In Imperial County, elevated PM10 levels can result from disturbance of soils by wind 

and human activity, and from transport from Mexico. Likely PM10 sources include the large desert 

areas (during high winds), unpaved roads, waste burning, agriculture, vacant lots, Immigration and 

Naturalization Service (Border Patrol) activities along the border, and Mexican sources. 

Best Available Control Measure (BACM) Development and Assessment 

USEPA issued a finding on August 3, 2004 that Imperial Valley failed to attain the PM10 NAAQS 

by the statutory deadline of December 31, 1994, and therefore reclassified the area from a moderate 

to a serious PM10 nonattainment area. Also on August 3, 2004, USEPA proposed to find that the 

Imperial Valley failed to attain by the serious area attainment date of December 31, 2001. The 

proposed rule generally described the necessary plan requirements and would require Imperial 

County submit its clean air plan, including BACM, within one year of the final action. As of the 

date of this report, USEPA has not taken final action. In addition, ICAPCD on August 9, 2005 

approved a natural event action plan (NEAP) to support the exclusion of natural events from 

attainment determinations, as allowed by USEPA’s Natural Event Policy (NEP). Although the final 

action by USEPA has not occurred, ICAPCD has proposed Regulation VIII BACM rules. EPA 

guidance recommends the following procedure for demonstrating the BACM has been implemented 

on all significant sources: 

 Inventory sources of PM10 and PM10 precursors 

 Determine a de minimis level for each pollutant 

 Identify significant source categories 

 Identify candidate control measures/technologies 

 Evaluate alternative control technologies for: 

- Technical feasibility analysis 

- Economic feasibility analysis 

- Environmental impacts 

- Select and implement measures

Traditionally, BACM development and assessment would be based on the State Implementation 

Plan (SIP) and its technical analyses. Key technical issues concerning emission inventory and 

natural events have not been resolved at this time. Unlike other serious non-attainment areas, 

ICAPCD is preparing its fugitive dust BACM in advance of the development and approval of a SIP. 

ICAPCD has prepared proposed Regulation VIII BACM (based on other recent serious area BACM 

rules) to meet the requirements of the NEP and to expedite BACM emission reductions. In 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

D R A F T F I N A L E N V I R O N -3- 

March 2004, ICAPCD began a review and assessment of BACM in other areas, which it has used as 

the basis on its proposed Regulation VIII BACM amendments. In October 2004 it gave a BACM 

presentation to local stakeholders that initiated the BACM rule development. ICAPCD prepared 

and released proposed Regulation VIII BACM rules in December 2004. These rules are being 

developed through a public process that includes a local Technical Advisory Committee (TAC). 

Membership in the TAC group includes representatives from Coalition of Labor and Business 

(COLAB), Farm Bureau, farmers, private industry, Bureau of Land Management (BLM), Border 

Patrol, Imperial Irrigation District, County Public Works Department and APCD. The initial 

meeting was December 16, 2004, with subsequent meetings held on January 4, 2005, January 11th, 

January 24th, and March 22nd. For the first time, on March 23, 2005, the TAC held a meeting with 

EPA to review EPA’s comments and receive information that would be useful in amending 

Regulation VIII rules. ARB participated by teleconference. The ICAPCD also conducted six 

public workshops to collect comments on Regulation VIII rules in Brawley, El Centro and 

Holtville. Workshop were held on May 31st, June 1st (two workshops) and June 2nd (two 

workshops), and August 4th. ICAPCD then re-submitted the Draft Regulation VIII Rules to EPA 

and ARB, for a second time, for informal comments. The EPA and ARB commented on these 

rules. On August 10, 2005, the district held a meeting with ARB and EPA at ARB’s headquarters, 

in Sacramento, to discuss their comments. An agreement was reached with EPA if their comments 

were addressed, that Regulation VIII rules would be declared BACM. Informal comments on these 

rules were also submitted by US Marine Corps and the California Department of Transportation 

(Caltrans). The current schedule is for the ICAPCD Board to hold an adoption hearing in November 

2005. 

Purpose 

This report presents the BACM determination based on proposed Regulation VIII amendments. It 

includes all elements of a BACM determination, including inventory assessment, calculation of the 

de minimis emission level, identification of significant sources (e.g. those sources which emit more 

than the de minimis level of emissions), a comparative analysis of proposed Regulation VIII 

amendments for significant sources with regulations adopted by serious PM10 non-attainment areas, 

and a presentation of the cost-effectiveness of individual dust control measures. The proposed 

Regulation VIII BACM amendments are based on BACM recently adopted by other serious nonattainment areas. As shown in this report, they apply to all significant fugitive dust sources in 

Imperial County and certain non-significant sources. This technical memorandum is based on 

USEPA’s guidance on BACM development and assessment, including: 1) an inventory sources of 

PM10 and PM10 precursors, 2) determination a de minimis level for each pollutant, 3) identification 

of significant source categories, 4) a comparative analysis of proposed Regulation VIII amendments 

and BACM in other serious non-attainment areas, and 5) emission reductions and costs associated 

with proposed Regulation VIII rules, as well as the cost-effectiveness of Regulation VIII measures 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

D R A F T F I N A L E N V I R O N -4- 

based on previous BACM analyses. These elements of a BACM assessment traditionally done in a 

SIP are being developed outside of the traditional SIP process to meet the requirements and 

schedule of the NEP and accelerate BACM implementation. 

Report Organization 

This report is organized as follows: 

 Section 2 presents a determination of PM10 De Minimis Levels for Imperial County based 

on the current emission inventory and ambient measurements. 

 Section 3 assesses the current PM10 emission inventory and identifies the potentially 

significant sources of PM10. This also includes an analysis of major stationary sources. 

 Section 4 presents the comparative analysis of the proposed Regulation VIII amendments 

with BACM in other serious PM10 non-attainment areas. 

 Section 5 presents the cost-effectiveness of proposed Regulation VIII amendments based on 

the cost-effectiveness analyses of previous BACM determinations. 

 Section 6 presents the conclusions and recommendations of this report. 

 Appendix A is an ENVIRON Technical Memorandum that presents the latest revisions of 

the Windblown Dust Study, which is used to calculate windblown from all sources except 

unpaved roads. 

 Appendix B presents the updated entrained and windblown unpaved road emission 

estimates. 

 Appendix C presents a detailed comparative analysis on a source-by-source basis for all 

proposed Regulation VIII rules for those sources with emissions above the de minimis 

emissions level. 

 Appendix D presents a detailed comparative analysis on a source-by-source basis for all 

proposed Regulation VIII rules for those sources with emissions below the de minimis 

emissions level. A comparative analysis is not required for these sources and is presented 

for informational purposes only. 

 Appendix E contains the version of the proposed Regulation VIII rules dated October 2005. 

This analysis is based upon this version of the proposed rules. 

 Appendix F is the Environmental Assessment and Finding of No Significant Impact 

prepared by BLM in April 2002 for Road and Trail Maintenance related to Border Patrol 

activities in Imperial County. 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

D R A F T F I N A L E N V I R O N -5- 

2. DETERMINATION OF PM10 DE MINIMUS LEVELS 

Background 

USEPA has established de minimis (DM) criteria for source categories contributing to PM10. 

Specifically, USEPA has established a source category contribution level of 1 μg/m3 based on the 

annual average PM10 national ambient air quality standard (NAAQS) and 5 μg/m3 based on the 24-

hour PM10 NAAQS1. If a source category contributes more than these levels to measured ambient 

PM10 concentrations in a serious nonattainment area, then BACM and/or Best Available Control 

Technology (BACT) are required to be implemented for that source. (BACM applies to certain 

area sources and BACT applies to stationary, mostly point, sources). The purpose of this report is 

to determine the DM conditions, on an emission per μg/m3

 basis, for sources of primary PM10 in 

Imperial County. (Ambient PM10 in most of Imperial County (e.g., those areas which do not border 

Mexicali) is overwhelmingly primary PM10, with little or no contribution from secondary aerosols). 

Once the DM levels are determined, then any source category which exceeds those limits would be 

subject to BACM/BACT. For individual stationary sources that meet the state and/or federal 

definition of PM10 major source, the last section of this chapter identifies those sources, whether 

BACT has been imposed (based on the date of the latest major modification permit), and, if BACT 

has not been applied, an assessment of the impact of the source’s emissions on ambient 

concentrations, relative to the significance thresholds. The BACM/BACT requirement does not 

apply to mobile sources of emissions. 

Ambient PM10 and Related Emission Inventories 

The DM level is calculated using the ambient PM10 data and the related emission inventory. There 

are six PM10 stations in Imperial County; from north to south, Niland, Westmorland, Brawley, El 

Centro, Calexico-Grant, and Calexico-Ethel. The last two stations are located in Calexico, next to 

the greater Mexicali, Mexico area. As shown in previous 179B(d) submittals, measures in excess 

of the annual average PM10 standard at the Calexico stations would not have occurred but for 

Mexican PM10 sources2. Since BACM and BACT can only be applied to U.S. sources, the 

Calexico stations will be excluded from the DM level determination. It is expected and assumed 

that ambient PM10 at these non-border ambient air monitoring stations is overwhelmingly primary 

PM10. (This is a conservative assumption when calculating the DM level, e.g., it produces the 

 

1

 State Implementation Plans for Serious PM10 Non-Attainment Areas, and Attainment Date Waivers for PM10 NonAttainment Areas Generally; Addendum to the General Preamble for the Implementation of Title I of the Clean Air 

Act Amendments of 1990, Federal Register, Vol. 59, No. 157, August 16, 1994. 

2

 “Imperial County PM10 Attainment Demonstration,” prepared by ENVIRON for the Imperial County Air Pollution 

District, July 2001. 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

D R A F T F I N A L E N V I R O N -6- 

smallest DM level.) The annual average PM10 levels for 2002 through 2004 for the non-Calexico 

stations are presented in Table 2-1, including the location of the maximum. 

Table 2-1. Annual Average PM10 levels in μg/m3 

 2002 2003 2004 

Annual Average 

PM10

57.1 (Westmorland) 

73.5 (Westmorland) 

60.3 without the 

flagged wildfire event 

56.3 (Westmorland) 

The peak 24-hour average values are not as straightforward. Table 2-2 reports the peak 24-hour 

average PM10 values for 2002 through 2004. The peak 24-hour average PM10 in 2003 was due to a 

wildfire event that has been flagged by USEPA as natural event. The more representative 2nd peak 

24-hour average PM10 values have been provided as more representative of local emissions. It 

should be noted that ICAPCD has requested that the August 18, 2002 and August 19, 2003 PM10

readings be flagged as natural events; however, for the purposes of this analysis, these readings will 

be used in the calculation of the DM level. (Using lower 24-hour average readings would increase 

the DM level, so this is a conservative approach.) 

Table 2-2. 24-Hour Average PM10 levels in μg/m3 

 2002 2003 2004 

Peak 24-Hour Average 

PM10

297 

(Westmorland 8/18) 

8401

(Westmorland 10/30) 

2nd high: 162 (8/19) 

354 

(Brawley 2/18) 

2nd high: 201 

(Westmorland 8/13) 1

 Wildfire event on October 30, 2003 

Except for the miscellaneous emissions category, emission data are from CARB 2004 emission 

inventory. The 2004 emissions inventory is used since this is the latest published inventory and 

there is little variation in the inventory over the 2002 through 2004 timeframe. The miscellaneous 

category includes fugitive dust sources such as windblown dust emissions, entrained unpaved and 

paved road emissions, construction emissions, and emissions from crop and cattle farming 

operations. A more detailed description of the emission inventory can be found in Chapter 3. 

Table 2-3 summarizes the Imperial County PM10 emissions, based on the CARB’s published 

inventory and revisions to the miscellaneous source emissions described in Chapter 3: 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

D R A F T F I N A L E N V I R O N -7- 

Table 2-3. Annual Average PM10 Emission 

Inventories for Imperial County in 

tons/day (Only non-zero categories 

are reported) 

Category Year 2004 

Fuel Combustion 0.41 

Industrial 2.77 

Miscellaneous1 279.98 

On-Road Mobile 0.38 

Other Mobile 0.69 

Total 284.23 

1 Miscellaneous source emissions are based on 2004 CARB estimates or revisions to 

the CARB estimates. See Chapter 3 for details. 

Since peak 24-hour emissions are not reported, our analysis relies on CARB’s reported peak 

seasonal (e.g. summer) inventories. For miscellaneous source emission estimate, annual average 

emission estimates are used for all sources except that the 24-hour hour average windblown 

emissions during the highest emitting month are used for non-unpaved road area sources (e.g. 

agricultural fields, shrub land, barren desert areas and dunes). These emissions will underestimate 

the peak day emissions, since they do not reflect the highest wind days. 

Table 2-4. Summer Average PM10 Emission 

Inventories for Imperial County in 

tons/day (Only non-zero categories are 

reported) 

Category Year 2004 

Fuel Combustion 0.49 

Industrial 2.76 

Miscellaneous 543.33 

On-Road Mobile 0.38 

Other Mobile 0.74 

Total 547.7 

1

 Miscellaneous source emissions are based on 2004 CARB 

estimates or revisions to the CARB estimates. Windblown 

emissions from all areas except unpaved roads are based on 

highest emission month. See Chapter 3 for details. 

Calculation of DM Levels 

The DM level is calculated by determining the emissions that are proportional to either 1 μg/m3 

(annual average) or 5 μg/m3 (24-hour average), based on the ambient data. The annual average DM 

level is derived from dividing the 2004 PM10 emissions of 284.23 tons/day by the average (2002 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

D R A F T F I N A L E N V I R O N -8- 

through 2004) ambient measurements of 57.9 μg/m3; the annual average DM is thus 4.9 tons/day 

per μg/m3

. (The wildfire event was excluded from the 2003 annual average, since it is 

unrepresentative of the annual average emissions. On a year-by-year basis, changing only the 

annual average PM10 maximum concentrations, the DM level calculation would be 5.0 for 2002, 

4.7 for 2003, and 5.0 for 2004.) 

For the 24-hour average, the summer average emissions (547.2 tons/day) are divided by the average 

ambient 24-hour PM10 levels (271 μg/m3

) and then multiplied by 5 (the DM is set by emissions 

proportional to 5 μg/m3

). This is very conservative since the summer and/or monthly average 

inventory will be smaller than the peak 24-hour inventory. The calculations exclude the wildfire 

events (10/30/03) as unrepresentative of local emissions and unrelated to the emissions inventory. 

The DM level for the peak 24-hour average is thus 10.1 tons/day per 5 μg/m3

. (On a year-by-year 

basis, changing only the 24-hour average PM10 maximum concentrations, the DM level calculation 

would be 9.2, 16.9, and 7.7 for 2002, 2003, and 2004, respectively.) 

Consistent with a conservative determination of the DM level, the DM level for PM10 in Imperial 

County is 4.9 tons/day. A further discussion of the DM level and emission source categories is 

presented in the next chapter. 

Analysis of Major PM10 Stationary Sources 

The previous analysis dealt with traditional fugitive PM10 sources and the assessment of their 

potential significance as it relates to BACM. The de minimis value was determined by comparing 

proportional ambient PM10 concentrations to average PM10 emissions. This analysis may not 

capture localized effects of major PM10 stationary sources. Stationary sources are required to 

implement Best Available Control Technology (BACT) to control PM10 emissions (Rule 207, New 

and Modified Stationary Source Review) and they are also required to comply with 20% opacity 

(Rule 403, Opacity of Emissions). In addition, stationary sources will be required to mitigate 

fugitive dust emissions from access roads, construction activities, handling and transferring of bulk 

materials and track-out and carry out according to the requirements on Regulation VIII. According 

to our 2004 stationary source emission inventory, there is only one PM10 major stationary source 

that operates in Imperial County. This source manufactures gypsum wallboard and related products 

and it is located approximately 20 miles west from the nearest PM10 monitoring site. In addition, it 

underwent an expansion within the last ten years, during which BACT was implemented on its 

major sources. Its impact on ICAPCD PM10 monitors is not significant. Regardless, this source is 

required to comply with all the above mentioned requirements and regulations; thus it meets the 

requirement for BACM and BACT, whether it is a significant source or not. 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

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3. Significant and De Minimis Source Categories 

Emission Inventory 

As stated in the introduction, there is no existing SIP inventory for Imperial County. This analysis 

uses the CARB 2004 PM10 emission inventory, published on CARB’s web site,3 revised cattle 

emissions, revised windblown dust model results, and updated entrained and windblown unpaved 

road dust estimates. Table 3-1 is a summary of the 2004 PM10 inventory for Imperial County. 

Except where noted, the emission estimates are based on the published CARB data. The next 

section discusses the revisions to the published CARB data and provides additional information on 

emission sub-categories. This report follows the same procedures as those in the San Joaquin 

Valley BACM/T and RACM/T Demonstration4

. The identification of significant and de minimis 

source categories can be found in the Conclusions section of this chapter. 

Table 3-1. 2004 Annual Average PM10 Emission Inventories for Imperial County in 

tons/day 

Source Category PM10 Comment 

Fuel Combustion 0.41 

Waste Disposal 0.00 

Cleaning/Surface 

Coatings 0.00 

Petroleum Prod/Mktg 0.00 

Industrial Processes 2.77 Includes Food / Agriculture (0.16), Mineral Processes (2.61) 

Solvent Evaporation 0.00 

Res Fuel Combustion 0.09 

Farming – Tilling 7.11 

Farming – Harvest 0.01 

Farming – Cattle 2.62 

Revised based on latest cattle population, emission factors and 

implementation of Rule 420 

Construction 1.91 

Paved Road Dust 4.09 

Unpaved Road Dust 61.00 

Entrained. Revised based on latest road mileage, activity, and 

emission factor estimates. 

Windblown –Unpaved 

Roads and Open Areas 188.30 

Unpaved Roads: Revised based on latest road mileage and 

emission factor estimates (30.95) 

Open Areas: Windblown Dust Study results, including 

Grassland (98.75), Dunes (19.85), Other Barren Lands (38.74), 

and Urban (0.01) 

 

3

 www.arb.ca.gov/app/emsinv/emssumcat_query.php?F_DIV=-

4&F_DD=Y&F_YR=2004&F_SEASON=A&SP=2005&F_AREA=CO&F_CO=13 

4

 Appendix G, BACM/T and RACM/T Demonstration for Sources of PM10 and PM10 Precursors in the San Joaquin 

Valley Air Basin. SJVAPCD 2003 PM10 SIP. SJVAPCD. April 2003. 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

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Table 3-1. 2004 Annual Average PM10 Emission Inventories for Imperial County in 

tons/day 

Source Category PM10 Comment 

Windblown – NonPasture Ag Lands 10.81 Windblown Dust Study results 

Windblown – Pasture 1.79 CARB estimate 

Fires 0.00 

Waste Burning 2.19 

Cooking 0.06 

On-Road Mobile 0.38 

Other Mobile 0.69 

TOTAL 284.23 

Inventory Discussion 

The inventory presented in the draft Regulation VIII BACM Analysis Report was based on 2003 

CARB emission inventory estimates. Based on the latest emissions modeling for many windblown 

dust sources and comments from CARB and EPA, the emission inventory for certain categories 

highlighted in the draft Report have been reviewed and revised. The following sections discuss 

those categories that have been revised. 

Windblown Dust (Except From Unpaved Roads)

In May 2004, ENVIRON prepared a report entitled “Development of a Windblown Fugitive Dust 

Model and Inventory for Imperial County,” for ICAPCD (Windblown Dust Study). The results of 

that report indicated that windblown PM10 from agricultural lands in Imperial County were 10.8 

tons/day, compared with the CARB estimate of 91.60 tons/day. This initial version of the 

Windblown Dust Study also estimated windblown annual average emissions from open barren lands 

to the east and west of the populated areas of Imperial County to be 792 tons/day; the model 

assumed that such lands were unvegetated and unstable. ICAPCD submitted this report to CARB 

and USEPA for their review and approval of the new emission inventory estimates. Based on those 

comments, ENVIRON has revised the windblown emissions model such that only the dune areas to 

the east are considered unvegetated and unstable, and that the remainder of the barren lands are 

stable and 9% vegetated (see Figure 3-1). Table 3-2 summarizes the results of the revised 

windblown dust estimates. 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

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Figure 3-1: Land Use and Land Classification Categories in Imperial County 
Technical Memorandum: Regulation VIII BACM Analysis 

D R A F T F I N A L 

-12- 

Table 3-2. Windblown Emissions from Lands by Month and Annual Average (tons/day) 

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov 

Agriculture 

8.59 11.32 19.93 28.48 12.95 16.26 7.37 4.33 9.76 0.38 6.60 

Urban 

0.07 0.00 0.00 0.03 0.01 0.00 0.00 0.00 0.00 0.00 0.00 

Desert - Other 

20.55 38.09 52.04 97.31 57.09 71.84 15.77 43.16 29.29 6.36 22.05 

Forest 

0.07 0.06 0.07 0.15 0.06 0.11 0.02 0.07 0.03 0.00 0.04 

Shub/Grassland 

96.15 102.12 120.63 243.24 97.52 189.86 40.64 139.97 63.84 7.32 64.00 

Desert - Dunes 

21.77 31.88 36.23 62.37 24.77 4.59 16.73 11.98 8.22 0.00 9.32 

TOTAL (TPD) 147.20 183.45 228.91 431.57 192.40 282.67 80.53 199.52 111.14 14.06 102.00 
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As noted, the original Windblown Dust Study estimate of emissions from barren lands was 792 

tons/day. With the revised assumptions, windblown dust from barren lands is 58.6 tons/day, of 

which 19.9 tons/day is emitted from the dune area. Emissions from all other categories are the same 

as in the May 2004 Windblown Dust Study Report. CARB and USEPA have recently approved the 

use of the Windblown Dust Study for estimating windblown dust emissions for all areas except 

unpaved roads. (Windblown unpaved road dust is estimated using the CARB methodology 

described further below.) 

Windblown Dust from Unpaved Roads

The CARB inventory web site references the August 1997 Windblown Dust – Unpaved Roads 

methodology. The 1993 windblown emissions from unpaved roads in that report are 5.90 tons/day. 

Based on discussion with CARB staff, it appears that the additional 73.5 tons/day was based on a 

previous estimate of windblown emissions from canal roads that assumed fewer canal road miles 

than current estimates and a much higher emission factor than currently recommended by CARB. 

ENVIRON has re-calculated the windblown emissions from all unpaved roads in Imperial County 

using the latest mileage information from Imperial County, the cities of Imperial County and the 

Imperial Irrigation District (IID) and the latest CARB emission factor. The results of that analysis 

are summarized in Table 3-3. 

Table 3-3. Windblown Emissions from Unpaved Roads 

Road Type Current

CARB 

2003 Comment 

city/county 7.82 5.9 Consistent 

canal 16.76 73.50 Updated emission factor 

farm 6.01 -- Not in ARB inventory 

BLM/USFS 0.37 -- Not in ARB inventory 

Total (tons/day) 30.95 79.40 

The greatest difference between the current estimates and the previous CARB estimate is canal road 

windblown emissions. Previous estimates used a much higher emission factor for windblown dust 

related to the canals. Details of the calculation of windblown emissions from unpaved roads can be 

found in Appendix B. 

Entrained Unpaved Road Dust

ICAPCD has collected updated information on the unpaved roads in its cities and in the county and 

along the canals. Previous CARB estimates were based on an emission factor of 2.27 lbs PM10 / 

VMT. The latest CARB-approved emission factor, used in the San Joaquin Valley PM10 BACM 

analysis, is 2.0 lbs PM10 / VMT. ICAPCD received information from the IC Public Works 

Department concerning miles of county roads with 50 or greater ADT. For this current estimated, 

ADT was set at the CARB default of 10 for all roads except high ADT county roads (assumed 70 
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ADT) and canal roads (assumed 5 ADT used in 1993 SIP). Table 3-4 summarizes the results of the 

entrained unpaved road emission estimates. 

Table 3-4. Entrained Unpaved Road Emissions 

Current 

CARB 

2003 Notes 

City/County 26.64 16.84

Assumes 70 ADT on high ADT county roads 

(if 10 ADT for all roads, ems = 13.62), 

consistent with the previous CARB estimate) 

Canal 31.56 12.78

1993 SIP: 3,128 mi canals; 1,682 mi canal 

roads / Current: 3156 mi canal; 6,312 mi roads. 

Assumes 5 trips/day (1993 SIP) 

Farm 1.41 1.41 Using new CARB method 

BLM/USFS 1.39 2.28

Using CARB methodology and 1993 road 

mileage 

Total (tons/day) 61.00 33.31 

The current estimate is about twice the previous CARB estimate. The difference is due to higher 

ADT estimates for certain county roads, and larger actual miles of canal roads. Information from 

the public works departments of Imperial County and its cities indicate that there are 7.5 miles of 

city roads and 1,354 miles of county roads, of which 217 miles have 50 or greater ADT. Entrained 

emissions from these city and county roads assumed the CARB default of 10 ADT for all roads, 

except the high ADT roads, where an ADT of 70 was assumed. As noted in the previous section, 

the 1993 SIP assumed 1,682 miles of canal roads, whereas the latest information from IID indicates 

that there are 6,312 miles of canal roads. The current estimate assumes 5 ADT for these roads, as 

assumed in the 1993 SIP. There is a discrepancy in the entrained emissions for farm roads that is 

probably due to an incorrect activity level in the previous estimate; the current estimate uses the 

latest CARB methodology and parameters. 

Cattle Feedlot Dust

The previous emission inventory for this category was in error; cattle feedlot dust was reported in 

both categories Cattle Feedlot Dust (ID# 620-616-540-000) and Livestock Husbandry – 

Agricultural Waste – Feedlot Cattle (ID# 620-618-0262-0103). Also, CARB recently revised the 

emission factor for dust from cattle operations. After discussions with CARB staff, a revised PM10

inventory for cattle in Imperial County has been calculated (Table 3-5). 
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Table 3-5. Imperial County Cattle-Related PM10 Emissions 

Livestock 

Category 

2004 Animal 

Totals 

Emission factor 

(lbs PM10/1000 

head/day) 

Uncontrolled 

PM10 emissions 

(tons/day) 

Baseline PM10

emissions 

(tons/day) 

Feedlot Cattle 360,486 28.9 5.21 2.60

Heifers 21,452 see milk cows 

Milk cows 3,615 6.72 0.01 0.01

Pink Veal 4,514 NA 

TOTAL 390,067 5.22 2.62

The CARB emission factors are applied to feedlot and milk cows only, based on the current CARB 

methodologies. The CARB milk cow factor assumes the presence of young stock, such as heifers 

and calves. There is currently no approved CARB emission factor for heifers and calves separate 

from milk cows. It is assumed that veal calf emissions are minimal, since they are not in open 

corrals. The baseline emissions reflect the effect of ICAPCD Rule 420, which requires that feedlot 

manure moisture be maintained between 20 and 40% and other measures. (The analysis assumes 

that rule penetration is 100%, since Rule 420 applies to all feed yards with more than 10 animals, 

and that there is 100% compliance. Emissions are 3.26 tons/day if 80% rule compliance is 

assumed.) 

Paved Road Dust

The CARB paved road dust estimate is based on previously assumed VMT levels of 4,569,000 

VMT/day. The estimate in the latest version of the EMFAC model is 4,340,000 VMT/day, 

approximately 5% less. An updated inventory would result in a smaller emission estimate for paved 

road dust. Given the relatively small contribution from paved road dust and the fact that emissions 

from this source are below the DM level, the inventory estimate has not formally been updated. 

Conclusions 

Based on the DM level of 4.9 tons/day, there are four PM10 sources above the de minimis level and 

therefore are significant source categories in Imperial County (Table 3-6). 
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Table 3-6. Significant Source Categories of PM10 (2004 

emissions in tons/day) 

Source Category 

Emissions 

(tons/day PM10) 

Windblown – open non-crop-farm areas 159.14 

Unpaved Roads (Entrained and Windblown) 91.95 

Windblown – Non-pasture agricultural lands 10.81 

Tilling dust 7.11 

All other source categories are below the DM level. For information purposes only, Table 3-7 

presents those sources below the DM level that emit more than 1 ton/day of PM10. It should be 

noted that ICAPCD Rule 420 and proposed Regulation VIII amendments apply to these sources. 

However, based on this analysis, BACM is not specifically required for these sources. 

Table 3-7. De Minimis Source Categories That Emit Greater 

than 1 ton/day of PM10 (These are NOT significant 

source categories) 

Source Category 

2004 Emissions 

(tons/day PM10) 

Paved Road dust 4.09 

Industrial (including Mineral) Processes 2.77 

Cattle feedlot dust (with Rule 420) 2.62 

Waste Burning 2.19 

Construction 1.91 

Agricultural Burning 1.59 

Sources categories that are both below the DM level and contribute less than 1 ton/day of PM10 are 

listed in Table 3-8. 

Table 3-8. De Minimus Source Categories That Emit Less 

than 1 ton/day of PM10

Source Category 2004 Emissions 

(tons/day PM10) 

Harvest Operations 0.01 

Cooking 0.06 

Fuel Combustion (All sources) 0.41 

Waste Disposal (All sources) 0.00 

Cleaning/Surface Coatings (All sources) 0.00 

Petroleum Production / Mrkg (All sources) 0.00 

On-Road Mobile* (All sources) 0.38 

Other Mobile* (All sources) 0.69 

* Not subject to a BACM/BACT analysis.
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4. COMPARATIVE ANALYSIS 

Introduction 

This chapter presents the comparative analysis for proposed Regulation VIII rules compared to the 

fugitive dust rules in other PM10 serious non-attainment areas. The most recent comparative 

analysis was done by San Joaquin Valley as part of their 2003 PM10 SIP; this analysis is based 

directly on Appendix G of that SIP5

. The serious non-attainment areas include San Joaquin Valley, 

Maricopa County (Phoenix area), Clark County (Las Vegas area), South Coast (Los Angeles Basin), 

and Coachella Valley (Palm Springs area). As noted in the San Joaquin Valley analysis, the 

comparison shows that control programs in the serious non-attainment areas are different based on 

local conditions and needs. For each of the fugitive dust control categories, comparisons are made 

between proposed Regulation VIII rules and similar rules or statutes applicable to the other serious 

non-attainment areas. For significant sources of PM10 (e.g. those with emissions above the DM 

level), the comparison will form the basis for evaluating the stringency of the proposed Regulation 

VIII measures compared to similar measures in other areas. Any thresholds and/or requirements for 

significant sources that are not as stringent as the most stringent in other areas will be justified 

based on local conditions, needs, and resources. Regulation VIII applies both to sources that are 

significant and require a stringency evaluation and to sources that are not significant and do not 

require a stringency evaluation. 

This section summarizes the comparative analysis for sources above the DM level. For each 

significant category, the thresholds and requirements are evaluated for stringency compared to 

similar rules in the other serious non-attainment areas. In cases where the proposed Regulation VIII 

rule thresholds and/or requirements are not as stringent as the most stringent thresholds and/or 

requirements from other areas, a justification is presented. Appendix C presents a detailed 

comparative analysis for sources with emissions greater than the DM level, including a stringency 

analysis and justification of any measures not deemed as stringent as the most stringent in other 

serious non-attainment areas. Appendix D presents a comparative analysis for sources with 

emissions below the DM level, although this is not a requirement of a BACM analysis. The 

thresholds and requirements for these sources are not evaluated for stringency, as this is not 

required. Similarly, the thresholds and requirements for sources in this section do not need to be 

justified based on a stringency evaluation. For each of the key source categories, controls 

 

5

 2003 San Joaquin Valley PM10 SIP, Appendix G, “Best Available Control Measures / Technology and Reasonably 

Available Control Measures / Technology Demonstration for Sources of PM10 and PM10 Precursors in the San Joaquin 

Valley Air Basin,” April 2004 (Final revised version). 
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implemented in the other serious PM10 non-attainment areas are given, along with the citations to 

the appropriate rule, statute, or referenced guidance. At the end of each segment, a discussion is 

provided which highlights the area or areas that have implemented the most stringent controls. As 

noted in the SJVAPCD BACM/T Determination, there is no statutory requirement that each control 

measure limit and/or requirement be as stringent as the most stringent limit and/or regulation 

adopted in any serious non-attainment area. 

Comparative Analysis for Significant Sources 

The following section presents a summary of the comparative analysis for sources above the DM 

level: unpaved roads and areas, disturbed areas, and agricultural sources. Appendix A presents a 

detailed comparative analysis of these sources, beginning with general requirements of the proposed 

Regulation VIII amendments related to visible dust emissions and stabilized surfaces for these 

sources (e.g., PAR 800, PR 804, PR 805, and PR 806). Next, the comparative analysis for each 

specific significant source is presented. Table 4-1 presents the rule source and control categories 

that are considered in the comparative analysis of the significant PM10 sources. Table 4-2 

summarizes the comparative analysis in Appendix C, including a discussion of the comparative 

stringency of the thresholds and requirements for each significant source category and a justification 

if the proposed Regulation VIII thresholds and/or requirements are not as stringent as the most 

stringent thresholds and/or requirements from other serious non-attainment areas. 

Table 4-1. Dust Control Source Categories for Sources above the DM Level 

RULE SOURCE CATEGORY CONTROL CATEGORY 

General Visible Dust Emissions 

General Definition of Stabilized Surface 

Unpaved Road Dust Applicability 

Unpaved Road Dust Control Requirements 

Unpaved Lots/Staging Areas Applicability 

Unpaved Lots/Staging Areas Requirements 

Disturbed Open Areas Applicability 

Disturbed Open Areas Control Measures 

Disturbed Open Areas Windblown 

Agricultural Sources1 Conservation Management Practices (CMPs) 

1 Only tilling and windblown emissions from agricultural sources are above the DM level, but the full source 

category will be compared to BACM in other areas. 

Sources on BLM Lands 

In the preceding analysis, unpaved roads and disturbed open areas are considered significant 

sources of PM10 in Imperial County. There are unpaved roads in the lands administered by BLM 

and the USFS; entrained and windblown dust from these roads is 1.8 tons/day, less than 2% of the 

92 tons/day for all unpaved roads. Almost all of the unpaved roads on BLM and USFS lands have 
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traffic levels under the Rule 805 threshold of 50 ADT. Of the over 2,666,600 acres comprising 

Imperial County over 77% is scrubland, barren land, or sand dunes. Most of this land is 

administered by BLM and the USFS. Except for areas used by the military or lands set aside for 

OHV use, most of the land is disturbed only by wind, water, and native animals. The lack of 

“destination” national or state parks, low County population density, general remoteness, and high 

summer temperatures minimizes man-made disturbances on most of this land. The exception to this 

is special off-roading events held in the dune areas. These special events occur 5 to 10 times per 

year, for a few days each. The BLM Dust Control Plan in PAR 800 requires control measures for 

these special events, even if annual or average day usage does not meet the thresholds in Rules 804 

and 805. 

The only Imperial County significant sources on BLM lands are unpaved roads and disturbed open 

areas. In addition, PAR 800 only exempts the recreational use of public lands (e.g., OHVs, allterrain vehicles, trucks, cars, motorcycles, motorbikes or motorbuggies), not other dust-producing 

activities such as construction, etc. The BLM Dust Control Provisions make clear that any 

stationary source activity must meet all applicable SIP provisions, including project- or activityspecific BACM. Thus, the focus of the Dust Control Plan provisions are on unpaved road and 

disturbed open area sources related to the recreational use of public lands. 

BLM sources are considered separate from the general dust source categories; this is in recognition 

of the special federal purposes of these agencies (e.g., habitat preservation and compliance with 

other area-specific environmental laws) and the inconsistency of requiring certain traditional dust 

control methods on these sources (e.g., vegetating disturbed dune areas approved for off-highway 

vehicle recreational use.). Many restrictions apply to actions on federal lands that have special 

purposes, such as habitats, national monuments and preserves. Common dust control measures, 

such as chemical stabilization and paving would not be allowed if it endangered native wildlife or 

impacted habitats. BLM is required to determine if a proposed dust control project conforms with 

the approved land use plan terms and conditions, as required by CFR 1610.5. Examples of such 

laws and plans include the federal Endangered Species Act, the California Desert Protection Act, 

the California Desert Conservation Area Plan and related tiered plans( e.g. the Yuha Basin ACEC 

Management Plan, Yuha Desert Habitat Management Plan, Yuha Desert Management Plan, 

Imperial San Dunes Recreation Area Management Plan (RAMP), Algodones Dunes Habitate 

Management Plan, Flat-tailed Horned Lizard Rangewide Strategy and Recovery Plan for Bighorn 

Sheep in the Peninsular Ranges, CA). 

BLM also must meet the requirements of NEPA for its projects. BLM is the appropriate lead 

agency for both NEPA and conformity determinations for dust control projects on BLM lands; 

mandating Rule 804 and 805 requirements without consideration of NEPA and conformity issues 

could unnecessarily involve ICAPCD in these issues and potentially delay implementation of 
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proposed dust control programs. Mandating PR 804 and 805 could also put BLM in the position of 

either violating an ICAPCD rule or potentially requiring a finding of overriding concerns for a 

given Environmental Assessment. Furthermore, any action on the use of the BLM lands has been 

highly litigious. Were ICAPCD to unilaterally impose requirements on BLM, it is possible that 

litigation and a temporary suspension of those rules while the litigation is resolved will occur. 

Thus, proposed Regulation VIII establishes a separate control program for the BLM lands, rather 

than imposing general Regulation VIII requirements on them on a dust source by dust source basis. 

ICAPCD believes that this is the most appropriate and expeditious way to reduce emissions from 

federal sources. 

ICAPCD and BLM have worked together on previous dust control programs, including the 

inclusion of PM10 control measures in the RAMP. BLM has also included PM10 prevention and 

mitigation measures based on its Environmental Assessment of its road and trail maintenance 

activities related to Border Patrol activities. Appendix F is the Environmental Assessment for this 

project. It is an example of the detailed environmental analysis required for projects on BLM lands 

and the use of the NEPA process to identify and implement PM10 prevention and mitigation 

measures. 
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Table 4-2. Dust Control Source Categories For Sources Above the DM Level CONTROL CATEGORY 

Imperial San Joaquin Valley South Coast Maricopa County Clark County 

General: Visible Dust Emissions 

• Limit visible 

emissions to not more than 20% opacity (PAR800) 

o All non-exempt 

sources (Ref: PAR 800) 

o Construction / 

demolition (de minimis source) (Ref : PR 802, Section E.1) 

o Bulk materials 

(de minimis source) (Ref : PR 802, Section E.1) 

o Open areas 

(significant source) (Ref : PR 804, Section E.1) 

o Unpaved roads 

and traffic areas (significant source) (Ref : PR 805, Section E.1) 

Test methods, including for unpaved road traffic in App. A and B (PAR800, G) 

• Limit visible 

emissions to not more than 20% opacity (Ref: R8021, Sect. 5.0; R8031, Sect 5.0; R8041, Sect. 5.7.2; R8051, Sect. 5.0; R8061, Sect. 5.2; R8071, Sect. 5.1; and 8081, Sect. 5.0) 

• Opacity test 

methods, including for unpaved road traffic. (Ref: R8011, Appendix A, Sections 1 and 2) 

• No visible 

emissions across property line. (Ref: R403(d)(1)) 

• Limit visible 

emissions to not more than 20% opacity (Ref R310, Sect. 301) 

• Opacity for dust 

generating activities based on minimum 12 observations, spaced 15 seconds apart (Ref: R310, Section 501.1(a)) 

• Opacity for 

unpaved parking lots and unpaved haul/access roads based on six vehicles, two readings per vehicle (Ref: R310, Section 501.1 (a) and (b)) 

• Limit visible 

emissions to not more than 20% opacity (Ref: AQR Section 91.2.1.4; AQR Section 92.2.1.3; AQR Section 93.2.1.5; AQR Section 94.5.3) 

• Opacity based on 

six vehicles, two readings per vehicle for unpaved surfaces And minimum 12 observations, spaced 15 seconds apart, for other sources. (Ref AQR Section 91.4.1.1 and AQR Section 94 AQR Section 94.5.3) 

• Limit 

construction visible emissions to not more than 100 yards (Ref: AQR Section 94.5.2(a)) 

6 Federal Register Vol. 69, No. 102; p.30035; May 26, 2004. 
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Table 4-2. Dust Control Source Categories For Sources Above the DM Level CONTROL CATEGORY 

Imperial San Joaquin Valley South Coast Maricopa County Clark County 

General: Definition of Stabilized Surface 

• A surface is 

considered to be stabilized if it meets at least one of the following conditions specified in below or as determined by test methods outline in Appendix B. 1. Visible crust; or 2. Threshold 

frictional velocity of 100 cm/sec or greater; or 

3. Flat vegetative 

cover of at least 50% that is attached or rooted vegetation; or unattached vegetative debris lying on the surface with a predominant horizontal orientation (not subject to wind movement); or 

4. Standing 

vegetative cover over 30% 

• Any disturbed 

surface that is resistant to wind blown fugitive dust and meets at least one of the following conditions: 

1. A visible crust 2. A threshold 

friction velocity of 100 cm/sec or greater 

3. A vegetative 

cover of at least 50% that is attached or rooted 

4. Unattached 

horizontal vegetative cover of at least 50% and windmovement resistant 

5. Vertical, 

rooted vegetation with at least 30% cover, or 10% cover where the soil threshold 

• Stabilized 

surface means any previously disturbed surface area or open storage pile which, through the application of dust suppressants, shows visual or other evidence of surface crusting and is resistant to wind driven 

• Fugitive dust and 

is demonstrated to be stabilized; (Ref: R403, (C)(28)) 

• Must meet at 

least one of the following standards: 

1. Maintain a 

visible crust 

2. Maintain a 

threshold friction velocity of 100 cm/sec or greater 

3. Maintain 

standing (rooted, vertical) vegetative cover of at least 30%, or 10% cover where the soil threshold friction velocity is at least 43 cm/sec 

4. Maintain flat 

(rooted or horizontal debris not subject to wind movement) of at least 50% 

5. Maintain a 

cover of at 

least 10% with 

• Stabilization 

standards: 

1. Establish 

visible crust 

2. Establish 

cover of at least 20% with non-erodible materials 

3. Establish soil 

threshold friction velocity of at least 100 cm/sec 

4. Comply with 

speciallyapproved alternative method 

7 September 26, 2005 telephone conversation with Rodney Langston, Clark County Department of Air Quality Management. 
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Table 4-2. Dust Control Source Categories For Sources Above the DM Level CONTROL CATEGORY 

Imperial San Joaquin Valley South Coast Maricopa County Clark County 

that is attached or rooted 

5. A standing 

vegetative cover of at least 10% that is attached or rooted with a predominate vertical orientation where the TFV is at least 43 centimeters per second when corrected for non-erodible elements 

6. A surface 

greater than or equal to 10% of non-erodible elements such as rocks, stones, or hard-packed clumps of soil (Ref: 800 C.28) 

Test methods: 

Test methods in Appendix A and B shall be used to determine compliance with the Regulation VIII rules (Ref PAR800, Section G) 

friction velocity is at least 43 cm/sec 

6. A surface that 

is at least 10% covered with non-erodible materials (Ref: R8011, Section 3.58) 

non-erodible materials 

6. Comply with 

speciallyapproved alternative method (Ref: R310, Section 302.3) 

8 Federal Register Vol. 69, No. 102, p.30035, May 26, 2004. 
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Table 4-2. Dust Control Source Categories For Sources Above the DM Level CONTROL CATEGORY 

Imperial San Joaquin Valley South Coast Maricopa County Clark County 

Unpaved Roads:  Applicability 

• Unpaved Haul/ 

Access Roads: All roads (Ref: PR805, Section E.1) 

• Unpaved Roads: 

50 or more average daily vehicle trips (Ref: PR805, Section E.2) 

• Canal Roads: 20 

or more ADT (Ref: PR805, Section E.4) 

(The implementation schedule for city and county roads is discussed in the next section, Unpaved Roads: Control Requirements.) 

• 26 annual average 

vehicle daily trips or more (Ref: R8061, Section 5.2.1) 

(The implementation schedule for city and county roads is discussed in the next section, Unpaved Roads: Control Requirements.) 

• For meeting 

standards of rule: 

o more than 50’ 

wide at all points, or 

o are not within 

25’ of property line, or 

o more than 20 

vehicle trips per day (Ref: R403(g)(2)(B)(iii)) 

• For treating 

unpaved roads: 

All roads greater than the average ADT of all unpaved roads within its jurisdiction, up to a set number of miles by 2006 (Ref: R1186(d)(4)) 

• 150 vehicles or 

more per day (Ref: R310.01, Section 304) 

• For new unpaved 

roads, there is no VDT limit (Ref AQR Section 91.2.1) 

• For existing 

unpaved roads (prior to June 22, 2000), the control measures apply to roads with 150 or more vehicles per day. 

9 EPA’s Technical Support Document for the San Joaquin Valley, California 2003 PM10 Plan and 2003 PM10 Plan Amendments., p. 31, January 
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Table 4-2. Dust Control Source Categories For Sources Above the DM Level CONTROL CATEGORY 

Imperial San Joaquin Valley South Coast Maricopa County Clark County 

Unpaved Roads: Control Requirements 

• For roads with 50 

ADVT or more and canal roads with 20 or greater ADVT, limit VDE to 20% opacity and comply with the requirements of a stabilized unpaved road surface by application and/or maintenance of at least one of the following control requirements (Ref: PR805, Section E.2, E.4): 

a) Pave (Section 

F.1.a) 

b) Apply chemical 

stabilization (, Section F.1.b) 

c) Apply and 

maintain gravel, asphalt, or other material of low 

• For unpaved roads 

with greater than 26 annual average vehicle trips per day, limit VDE to 20% opacity and implement at least one of the following control measures: a) apply water b) apply uniform 

layer of washed gravel 

c) apply 

chemical/organic dust suppressant 

d) use vegetative 

materials 

e) pave f) use any other 

approved method to limit VDE to 20% opacity and meets the condition of a 

• Annually treat 

unpaved public roads beginning in 1998 and continuing for each of 8 years thereafter by implementing one of the following (Ref: R1186(d)(4)): a) Pave at least 

one mile with typical roadway material (Ref: ibid, (d)(4)(A)) 

b) Apply 

chemical stabilizers to at least two miles to maintain stabilized surface (Ref: ibid, (B)) 

• For 150 vehicles or 

more per day, implement at least one of the following BACM (Ref: R310.01, Section 304): 

a) Pave b) Apply dust 

suppressants 

c) Uniformly 

apply and maintain surface gravel (Ref: ibid, Section 304.1) 

• For existing 

roads, BACM, as above, must be implemented by: a) June 10, 2000 

for more than 250 vehicle trips 

b) June 10, 2004 

for more than 150 vehicle trips 

• Implement one 

control measure on 1/3 of unpaved roads with 150+ VDT by June 1, 2001 (Ref: AQR Section 91.2.1.1(a)) 

• Implement one 

control measure on 2/3 of unpaved roads with 150+ VDT by June 1, 2002 (Ref: ibid, (b)) 

• Implement one 

control measure on all unpaved roads with 150+ VDT by June 1, 2003 (Ref: ibid, (c)) 

• For any unpaved 

road with newly found levels of 150+ VDT, implement one control measure 

10 Federal Register Vol. 69, No. 102, p.30019, May 26, 2004. 
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Table 4-2. Dust Control Source Categories For Sources Above the DM Level CONTROL CATEGORY 

Imperial San Joaquin Valley South Coast Maricopa County Clark County 

silt content of a depth of 3 or more inches (Section F.1.c) 

d) Apply water 

one ore more times daily (Section F.1.d) 

e) Permanent road 

closure (Section F.1.e) 

f) Restrict 

unauthorized vehicle access (Ref: PR805, Section F.1.f) 

g) Any other 

method that limits VDE to 20% opacity and meets conditions of a stabilized unpaved road (Section F.1.g) 

• Within an urban 

area, construction of a new unpaved road is prohibited, unless it meets the definition of a Temporary Unpaved Road. 

• Cities and the 

stabilized unpaved road (Ref: R8061, Section 5.2.1) 

• As option to above, 

obtain Fugitive PM10 Management 

Plan (Ref: ibid, Section 5.2.1) with specific requirements. 

• Within an urban 

area, construction of a new unpaved road is prohibited, unless it meets the definition of a temporary unpaved Road. 

• Cities and the 

County shall treat an average of 20% of applicable roads per year form 2006 through 2010, to a 

cap of 5 miles per year per jurisdiction. A statement of financial hardship can be submitted if a jurisdiction cannot afford to meet the requirements of this 

c) Speed control 

(15 mph) on at least three miles of road surface: 

(Ref: ibid, 304.2) 

• BACM must meet 

the following standards: a) Limit VDE to 

20% opacity 

b) Do not equal 

or exceed 0.33 oz/ft2, or 

c) Do not 

exceed 6% silt content (Ref: ibid, 304.3) 

within 365 days (Ref: ibid, (d)) 

• For unpaved roads 

with less than 150 VDT, maintain stabilized surface standards within 365 days of determination of non-stabilized surface (Note: not a SIP measure) 

• No new unpaved 

roads are to be constructed after June 22, 2000 (Ref: AQR Section 91.2.1.2) 

• Applicable control 

measures are as follows: 

a) Pave b) Apply dust 

palliatives to meet stab. standards 

• Stabilization 

standards: 

a) Limit VDE to 

20% opacity 

b) Do not equal or 

exceed 0.33 oz/ft2, or 

c) Do not exceed 

6% silt content

11 Federal Register Vol. 69, No. 102, p.30035, May 26, 2004. 
Technical Memorandum: Regulation VIII BACM Analysis 

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Table 4-2. Dust Control Source Categories For Sources Above the DM Level CONTROL CATEGORY 

Imperial San Joaquin Valley South Coast Maricopa County Clark County 

County shall comply with Section E.2 by treating an average of 10% of applicable roads per year form 2006 through 2015.(Ref: PR805, Section E.7) 

section. (Ref R8061, Section 5.2.3). 

(Ref: ibid, 91.2.1.4) 

Unpaved Lots: Applicability 

• Unpaved traffic 

areas larger than one (1) acre and with 75 or more average vehicle trips per day shall comply with one or more of the requirements of Section F.3 so as to limit VDE to 20% opacity (Ref: PR805, Section E.4) 

• Areas with 

AADT of 50 or more (Ref: R8071, Section 4.1) 

• Agricultural 

sources exempt from Rule 8081 are also exempt from R8071. 

(Note: South Coast does not have rule language specifying this category. It is presumed that Rule 403 provisions for either unpaved roads, or disturbed surface areas would apply.) 

• Over 100 

vehicles entering or parking (Ref: R310.01, Section 303) 

• No minimum 

vehicle limit specified for parking lots. (Ref: AQR, Section 92.2.1) 

• No minimum 

vehicle limit specified for staging areas (Ref: AQR Section 94 Handbook, CST 17) 

12 EPA’s Technical Support Document for the San Joaquin Valley, California 2003 PM10 Plan and 2003 PM10 Plan Amendments, p. 34-5, Janua
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Table 4-2. Dust Control Source Categories For Sources Above the DM Level CONTROL CATEGORY 

Imperial San Joaquin Valley South Coast Maricopa County Clark County 

Unpaved Lots: Requirements 

For unpaved traffic areas larger than one (1) acre and with 75 or more average vehicle trips per day shall comply with one or more of the requirements of Section F.3 (listed below) so as to limit VDE to 20% opacity: • Pave or (Ref: 

PR805, Section 

• For days with 50 

or more vehicle trips, limit VDE to 20% opacity and implement at least one of the following control measures: 

o apply water o apply uniform 

layer of washed gravel 

o apply 

(No specific rule language for this category. See measures for “Unpaved Roads” for presumed applicable BACM.) 

• If utilized less than 

35 days per year, use one of following: 

a) Apply dust 

suppressants to maintain stabilized surface 

b) Apply and 

maintain gravel to maintain 

• For unpaved 

parking lots, use one of following: 

a) Pave 

b) Apply dust 

palliatives to maintain stabilized surface 

c) Apply dust 

palliatives to travel lanes, and apply 
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Table 4-2. Dust Control Source Categories For Sources Above the DM Level CONTROL CATEGORY 

Imperial San Joaquin Valley South Coast Maricopa County Clark County 

F.3.a) 

• Apply chemical 

stabilizers (Ref: PR805, Section F.3.b) 

• Apply and 

maintain gravel, recrushed/recycled asphalt or other material of low silt content to a depth greater than 3 inches (Ref: PR805, Section F.3.c) 

• Wetting. Apply 

water one or more times daily (Ref: PR805, Section F.3.d) 

chemical/organic dust suppressant 

o use vegetative 

materials 

o pave o use any other 

method to limit VDE to 20% opacity (Ref: R8071, Section 5.1.1) 

• For days with 100 

or more vehicle trips, as above and comply with requirements for stabilized surface (Ref: ibid, Section 5.1.2) 

• On each day that 

25 or more VDT with 3 or more axles will occur on an unpaved vehicle/equipment traffic area, special requirements (Ref: R8071, Section 5.1.3). 

• On each day when 

a special event will result in 1,000 or more vehicles, special requirements. 

stabilized surface (Ref: R310.01, Section 303, and 303.1) 

• If utilized at least 

35 days per year: 

a) Add option, to 

above, to pave (Ref: ibid; also R310, Table 1, 1B,2B,3B) 

gravel to a depth of two inches in the parking areas to maintain stabilized surface (Ref: AQR Section 92.2.1 and 92.2.1.2) 

• If parking lot is 

used intermittently, less than 35 days per year, and the lot was in existence prior to June 22, then application may be limited to period of use (Ref; ibid, 92.2.1 and 92.2.1.1) 

• For staging areas: 

o Limit size of 

staging areas (Ref AQR, Section 94 Handbook, CST 17-1) 

o Apply water 

(Ref: ibid, CST 17-2) 

o Apply dust 

palliative (Ref: ibid, CST 17-3) 

o Limit vehicle 

speeds to 15 
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Table 4-2. Dust Control Source Categories For Sources Above the DM Level CONTROL CATEGORY 

Imperial San Joaquin Valley South Coast Maricopa County Clark County 

(Ref: R8071, Section 5.1.4). 

• As option to 

above, obtain Fugitive PM10

Management Plan (Ref: ibid, Section 5.2.1, 5.2.2, and 5.2.3) 



mph (Ref: ibid, CST 17-4) 

o Limit ingress 

and egress points (Ref: ibid, CST 17-5) 

Unpaved Roads: Canal Roads 

• For Canal Roads 

with 20 or more ADT (Ref: PR805, Section E.3) a) Stock Triploid 

Grass carp in canals to reduce maintenance trips or (Ref: PR805, Section F.2.a) 

b) Install remote 

control delivery gates or (Ref: PR805, Section F.2.a) 

c) Implement Silt 

removal program to delay grading of spoil piles or (Ref: PR805, Section F.2.a) 

d) Permanent road 

closure or (Ref: PR805, Section 

(No requirements specified.) 

(No requirements specified.) 

(No requirements specified.) 

(No requirements specified.) 
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Table 4-2. Dust Control Source Categories For Sources Above the DM Level CONTROL CATEGORY 

Imperial San Joaquin Valley South Coast Maricopa County Clark County 

F.2.a) 

e) Convert open 

canals to pipeline or (Ref: PR805, Section F.2.a) 

f) Line canals to 

eliminate maintenance for silt/weed control or (Ref: PR805, Section F.2.a) 

g) Initiate canal 

bank surface maintenance (Ref: PR805, Section F.2.a) 
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Table 4-2. Dust Control Source Categories For Sources Above the DM Level CONTROL CATEGORY 

Imperial San Joaquin Valley South Coast Maricopa County Clark County 

Disturbed Open Areas: Applicability 

• 0.5 acres or larger 

in urban areas, or 3.0 acres or more in rural areas; and contains at least 1,000 square feet of disturbed surface area (Ref: PR804, Section B) 

• This rule applies 

to any open area having 0.5 acres or more within urban areas, or 3.0 acres or more within rural areas; and contains at least 1000 square feet of disturbed surface area (R8051, Section 2.0). 

• No limit Rule 310, Section 102 

exempts disturbed open areas which are not located at sources requiring “any permit under these rules.” However, most open areas will not have need for permits. Section 303 requires a dust control plan (presumed to be what is referred to in Section 102 as a “permit”), for all sources that involve earthmoving operations of 0.10 acres or greater. Since soil disturbances can occur for reasons other than earthmoving, for example, off-road vehicle traverses, it appears that many disturbed open areas, vacant lots, etc, may be exempt under these rules. 

• 5,000 square feet 

or larger (nonag) (Ref: AQR Section 90.1.2 and 90.2.1) 

13 EPA’s Technical Support Document for the San Joaquin Valley, California 2003 PM10 Plan and 2003 PM10 Plan Amendments., p. 37-38, Janu14 Imperial County Assessors Office parcel data, 2001. 
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Table 4-2. Dust Control Source Categories For Sources Above the DM Level CONTROL CATEGORY 

Imperial San Joaquin Valley South Coast Maricopa County Clark County 

Disturbed Open Areas: Control Measures 

Use one or more of the following measures to comply with the stabilized surface requirements so as to limit open areas to VDE of 20% opacity (Ref: PR804, Section E.1) • Apply and 

maintain water or dust suppressant to all unvegetated areas (Ref: PR804, Section F.1.a) 

• Establish 

vegetation on all previously disturbed areas (Ref: PR804, Section F.1.b) 

• Pave, apply gravel, 

chemical stabilizers/suppressants (Ref: PR804, Section F.1.c) 

• Prevent 

unauthorized vehicle access by posting “No Trespassing” signs or installing physical barriers to prevent access 

(Ref: PR804, 

Use one or more of the following measures to comply with the stabilized surface requirements so as to limit open areas to VDE of 20% opacity (Ref: Rule 8051, Section 5.0) • Apply water/dust 

suppressants to unvegetated areas sufficient to limit VDE to 20% opacity (Ref: R8051, Table 8051-1, A1) 

• Establish 

vegetation to limit VDE to 20% opacity (Ref: ibid, A2) 

• Pave, apply 

gravel, apply stabilizers to limit VDE to 20% opacity (Ref: ibid, A3) 

• Upon evidence of 

trespass, post “no trespass” signs or install barriers to prevent access to area (Ref: ibid, B) 

• Apply chemical 

stabilizers (Ref: R403 Handbook, BACM (Q)) 

• Water with 

sufficient frequency to establish a surface crust (Ref: ibid, (R)) 

• Establish 

(drought-resistant) vegetation as quickly as possible (Ref: ibid, (T)) 

• Restore vegetative 

ground cover and soil characteristics similar to native Conditions (Ref: R310, Table 1, 1E) 

• Pave, apply gravel, 

apply stabilizer to meet stabilized standards (Ref: ibid, 2E) 

• Establish 

vegetation to meet stabilized standards (Ref: ibid, 3E) 

• Stabilized 

standards, one of the following (Ref: R310, Section 302.3): 

• Upon evidence of 

soil disturbance by motor vehicles, prevent trespass, parking, and access by installing barriers, curbs, fences, gates, posts, signs, shrubs, and trees. (Ref: AQR Section 90.2.1.1(a)) 

• Apply gravel or 

chemical stabilizers to meet one of stabilization standards (Ref: ibid, (b)) 

• Stabilization 

standards – see General: Definition of a Stabilized Surface above (Ref: AQR Section 90.2.1.2) 

15 Federal Register Vol. 69, No. 102, p.30035, May 26, 2004. 
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Table 4-2. Dust Control Source Categories For Sources Above the DM Level CONTROL CATEGORY 

Imperial San Joaquin Valley South Coast Maricopa County Clark County 

Section E.2) 

Disturbed Open Areas: Windblown 

There are no specific exemptions for wind events in the proposed Regulation VIII amendments, thus no requirements for windblown dust are specified. However, opacity and stabilized surface requirements remain, independent of wind speed. 

(No specific requirements) 

As contingency measures for a highwind exemption from certain rule requirements: • If inactive, apply 

water or chemical stabilizers to maintain a stabilized surface for six months (Ref: R403, Table 3, 0B) 

• Apply chemical 

stabilizers prior to wind event (Ref: ibid, 1B) 

• Apply water 3 to 4 

times per day (Ref: ibid, 2B) 

• Establish vegetative 

ground cover within 21 days after active operations have 

• Apply gravel or 

dust suppressants (Ref: R310, Table 2, 1B) 

• Apply water 3 times 

per day; if evidence of wind driven fugitive dust, increase watering to 4 times per day (Ref: ibid, 2B) 

(No specific wind requirements, however, the general requirements for disturbed surface areas include provisions which are intended to reduce windblown dust: • Prevent access to 

limit soil disturbance (Ref: AQR Section 94 Handbook, CST 11) 

• Stabilize soil, using 

dust palliative or vegetation to maintain stabilized surface (Ref: ibid, CST 11-4 and 11-5) 

• Pave or apply 
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Table 4-2. Dust Control Source Categories For Sources Above the DM Level CONTROL CATEGORY 

Imperial San Joaquin Valley South Coast Maricopa County Clark County 

ceased (Ref: ibid, 3B) 

surface rock to maintain stabilized surface (Ref: ibid, CST 11-6)) 

Agricultural Sources: CMPs 

For owner/operators of commercial farms on sites greater than or equal to 40 acres, implement at least one of the following in each category: 

• Land preparation 

and cultivation (Ref: PR806, Section E.1): 

a. alternative till b. bed/row size 

spacing 

c. chemical/fertig

ation 

d. combined 

operations 

e. conservation 

irrigation 

f. conservation 

tillage 

g. cover crops h. equipment 

changes 

i. fallowing land j. pest control k. mulching l. night farming m. non 

SJVAPCD Rule 4550 requires the submittal of a conservation management plan for sites with more than 100 acres with 1 conservation management practice (CMP) for each category: • Land preparation 

and cultivation: same as Imperial County with addition of floor management (nut crops), time of planting and transplanting (some vegetable crops) options. 

• Harvest: same as 

Imperial County with addition of continuous tray/D.O.V. (dry fruit crops), fallowing land; and floor management (nut crops) options. 

For agricultural operations within the South Coast Air Basin, with combined disturbed surface area of 10 acres or more, the standards of Rule 403 apply after July 1, 1999 unless Best Management Practices as delineated in the Rule 403 Agricultural Handbook are implemented. (Ref: R403(h)(1)) Best Management Practices as described in the Agricultural Handbook are as follows: 

a) Active 

conservation practices 

b) Inactive 

conservation practices 

c) Farm yard areas d) Trackout 

In May 2000, the Agricultural BMP Committee adopted the agricultural PM10

general permit, which became effective by rule on May 12, 2000 (Arizona Administrative Code [AAC], R18-2- 610 and 611). The Committee identified 34 BMPs that focus on feasible, effective, and common sense practices while minimizing negative economic impacts on local agriculture. (These BMPs were based on the BMP’s in the South Coast Agricultural Handbook). The general permit requires that a commercial farmer implement at least one BMP to control PM10 for each of the 

(No requirements for this source) 

16 Federal Register Vol. 69, No. 102, p.30035, May 26, 2004. 
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Table 4-2. Dust Control Source Categories For Sources Above the DM Level CONTROL CATEGORY 

Imperial San Joaquin Valley South Coast Maricopa County Clark County 

tillage/chemical tillage 

n. organic 

practices 

o. precision 

farming 

p. transgenic 

crops 

• Harvesting (Ref: 

PR806, Section E.2): 

a. bailing/large 

bails 

b. combined 

operations 

c. equipment 

changes 

d. green chop e. hand harvesting f. fallowing land g. nigh harvesting h. no burning i. pre-harvesting 

soil preparation 

j. shed packing k. shuttle system / 

large carrier 

• Unpaved farm 

roads and traffic areas (Ref: PR806, Section E.3,4): a. chips/mulches, 

organic materials, polymers, road oil and sand 

b. gravel 

• Unpaved farm 

roads and traffic areas: same as Imperial County with the addition of mechanical pruning (tree and vine crops) option. 

conservation practices 

e) Unpaved road 

conservation practices 

f) Storage pile 

conservation practices 

• (Ref: Guide to 

Agricultural PM10

Dust Control Practices, dated June 1999) 

following three categories: tillage and harvest, noncropland, and cropland. The general permit requires a commercial farmer to comply by December 31, 2001. 
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Table 4-2. Dust Control Source Categories For Sources Above the DM Level CONTROL CATEGORY 

Imperial San Joaquin Valley South Coast Maricopa County Clark County 

c. paving d. restricted 

access 

e. speed limit f. track-out 

control 

g. water h. wind barrier 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

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Comparative Analysis for Sources With Emissions Less Than the DM Level 

Sources with emissions below the DM level do not need to be included in the BACM determination. 

Table 4-3 presents the rule source categories for these sources with emissions below the DM level. 

For information purposes only, Appendix D presents a comparative analysis for these sources. 

Table 4-3. Dust Control Source Categories For Sources Below the DM Limit 

RULE SOURCE CATEGORY CONTROL CATEGORY 

Construction Visible Dust Emissions 

Construction Demolition 

Construction Pre-Earthmoving 

Construction Earthmoving 

Construction Demolition 

Construction Inactive Disturbed Land 

Construction Windblown 

Construction Dust Plan Applicability 

Construction Dust Plan Requirements 

Bulk Materials Handling/Storage 

Bulk Materials Transport 

Bulk Materials Outdoor Chute/Conveyor 

Bulk Materials Windblown 

Carryout/Trackout Removal 

Carryout/Trackout Prevention 

Carryout/Trackout Clean-Up Methods 

Paved Road Dust New/Modified Roads 

Paved Road Dust Erosion Clean-Up 

Paved Road Dust Street Sweeping 

Cattle feedlots Requirements 

Weed Abatement Requirements 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

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5. IMPACT ANALYSIS 

This section presents information about the emission reductions, cost and cost-effectiveness of the 

proposed to Regulation VIII amendments. This report relies on previous analysis of BACM 

effectiveness, costs, and cost-effectiveness prepared for the 1993 SIP for PM10 in the Imperial 

Valley17 rule. It also relies on information is taken from the October 18, 2004 CARB staff report 

entitled “Proposed List of Measures to Reduce Particulate Matter – PM10 and PM2.5,” and the April 

28, 2003 SJVAPCD Appendix G to their 2003 PM10 Plan, entitled “Best Available Control 

Measures / Technology and Reasonably Available Control Measures / Technology Demonstration 

for Sources of PM10 and PM10 Precursors in the San Joaquin Valley.” (The CARB staff report 

summarizes PM10 control measures adopted in California and their reported cost-effectiveness.) 

Emission reduction and cost estimates are provided for all proposed Regulation VIII rules. As 

noted in Chapter 1, this BACM analysis has not been prepared as part of the SIP development 

process. 

Control Effectiveness and Cost Information 

As noted above, the control effectiveness of measures within proposed Regulation VIII are based on 

previously published estimates, including those used in the 1993 Imperial Valley PM10 SIP, the 

2003 San Joaquin Valley PM10 SIP and, where necessary, other serious PM10 non-attainment area 

SIPs and related technical documents. Table 5-1 summarizes, for each proposed Regulation VIII 

rule, estimated emissions from sources covered by the proposed rule, the percentage of those 

emissions that are subject to control requirements, the composite control factor for those controls, 

and the estimated emission reductions at full implementation. Cost information is based on 

information from the 1993 Imperial Valley PM10 SIP, the 2003 San Joaquin Valley PM10 SIP18 and 

the latest information from Imperial County public works department. The following subsections 

present the input information and assumptions used in Table 5-1 

Table 5-1. Proposed Regulation VIII Emission Reduction Summary 

Proposed Rule Emissions 

(tons/day) 

Applicability 

(percent) 

Composite 

Control Factor 

Emission 

Reductions 

801 (Construction) 1.91 100 0.12 0.23 

802(Bulk Materials) 2.61 10 0.5 0.13 

803 (Track-out) 4.09 18.4 0.6 0.45 

 

17 ICAPCD, “State Implementation Plan for PM10 in the Imperial Valley,” Final, adopted September 28, 1993. 18 Appendix G, BACM/T and RACM/T Demonstration for Sources of PM10 and PM10 Precursors in the San Joaquin 

Valley Air Basin. SJVAPCD 2003 PM10 SIP. SJVAPCD. April 2003. 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

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Table 5-1. Proposed Regulation VIII Emission Reduction Summary 

Proposed Rule Emissions 

(tons/day) 

Applicability 

(percent) 

Composite 

Control Factor 

Emission 

Reductions 

804 (Open Areas) 163.36 1 0.7 1.14 

805 (Non-Farm 

Unpaved Roads) 84.53 20 0.6 10.09 

805 (Paved Roads) 4.09 1 0.8 0.03 

806 (CMPs) 25.35 see below see below 4.16 

TOTAL 281.85 16.23 

There is no current information on which control options will be used by sources to comply with the 

proposed rules, so information on control options in each proposed rule is presented in the 

following subsections. The exception is the treatment of unpaved roads by Imperial County to 

comply with PR 805; specific cost information is provided for the treatment of applicable roads. 

PR 801: Construction

PR 801 applies to any construction or other earth moving activities. Only construction at existing 

single family homes is exempt, so the rule applies to all new construction emissions. PR 801 

upgrades the RACM controls in previous Rule 800 to BACM controls consistent with requirements 

in other serious non-attainment areas. Emission estimates for construction already include the 

effect of basic RACM controls, such as watering. BACM upgrades will require additional watering 

and/or stabilizing during and after construction activities. As noted in the South Coast 1997 

AQMP, such BACM upgrades provide an additional control efficiency of approximately 12%, 

mostly from additional water and/or stabilizing during and after construction or other earthmoving 

activities. Overall reductions from PR 801 are estimated at 0.23 tons/day. 

Estimated costs for certain construction-related controls include: additional use of water trucks 

($3,152 per 40 acre project)19; water sprinkler ($30 per acre); and dust control plans and related 

costs ($112/acre)20; . Actual costs for compliance is subject to the control options used by the site 

and the level of dust control currently practiced. 

PR 802: Bulk Materials

PR 802 applies to the handling, storage, and transport of bulk materials. There is not an explicit 

inventory category for bulk materials, although it can be assumed that the majority of handling, 

storage, and transport of these materials occur at mineral processing facilities and, to some extent, at 

 

19 Final BACM Technological and Economic Feasibility Analysis, SJVAPCD 2003 PM10 SIP, April 2003. 20 SCAQMD, Rule 403 Final Staff Report, September 1992. 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

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construction sites. It is assumed that 10% of the emissions from mineral processing facilities are 

related to bulk materials. Wetting of bulk material piles and transfer points has an estimated control 

efficiency of 50%. (San Joaquin estimated a 56 to 81% control efficiency.) Emission reductions 

from transfer controls have not been estimated, but most mineral processing plants are operating 

under ICAPCD permits that require control at major transfer points. Overall reductions from PR 

801 are estimated at 0.23 tons/day. 

Estimated costs for PR 802-related controls include: Truck covers ($900 per truck)21; and 3-sided 

enclosure ($830 per enclosure)22. 

PR 803: Carry-out and Track-out

PR 803 applies to material carried or tracked out onto paved roadways. There is not an explicit 

inventory category for track-out, although it can be assumed that a given percentage of the silt 

loading on paved road surfaces is from track-out. EPA guidance23 indicates that 46% of paved road 

deposition is attributable to mud and dirt carry-out. In addition, many permanent facilities (e.g. 

mineral processing facilities) currently implement PR805 track-out controls. It is assumed that 40% 

of the track-out emissions originate from construction and other temporary sites that have not 

previously been using PR805 controls. Thus, the 18% of paved road dust will be affected by new 

PR 803 controls. Overall reductions from PR 803 are estimated at 0.45 tons/day. 

Estimated costs for PR 803-related controls include: paving access points ($6,000 to $8,500 per 

access point)24; chemical stabilization ($984)25; gravelling ($680 to $1,360 per year per access 

point)26; and track-out control device ($3,500 to $4,800 plus maintenance costs)27. 

PR 804: Open Areas

PR 804 applies to non-agricultural rural open areas more than 3 acres (rural) or 0.5 acres (urban). 

Review of Imperial County parcel data indicates that over 99.5% of parcels are greater than 3 acres 

in size. However, 77.5% of Imperial County is desert and/or scrubland, much of which is under the 

control of BLM or other federal agencies. (BLM areas are exempt from Rule 804, but are subject to 

dust control plan requirements in PAR 800. Agricultural areas, which cover 21% of Imperial 

County, are subject to PR 806.) For purposes of estimating emission reductions, it is assumed that 

the non-BLM desert and scrubland areas are not disturbed by man due to their remoteness. It is 

assumed that most disturbed land will occur relatively near the urban areas, which represent 1.5% of 

Imperial County. Assuming that up to 2/3rds of that area could be disturbed, the applicability is 

estimated to be 1% or less. The composite control factor is estimated to be 70% (based on control 

efficiencies cited in San Joaquin Valley’s 2003 PM10 SIP). Overall reductions from PR 804 are 

estimated at 1.07 tons/day. (It should be noted that the BLM dust control plan could result in 

additional reductions from this source, depending on the extent of BLM areas that are disturbed by 

 

21 ICAPCD, “State Implementation Plan for PM10 in the Imperial Valley,” Final, adopted September 28, 1993. 22 Final BACM Technological and Economic Feasibility Analysis, SJVAPCD 2003 PM10 SIP, April 2003. 23 EPA, Fugitive Dust Background Document and Technical Information Document for Best Available Control 

Measures, Document Number EPA-450/2-92-004, Office of Air Quality Planning and Standards, 1992. 24 ICAPCD, “State Implementation Plan for PM10 in the Imperial Valley,” Final, adopted September 28, 1993. and 

SCAQMD, Rule 403 Final Staff Report, Appendix G, February 1997. 

25 SCAQMD, Rule 403 Final Staff Report, Appendix G, February 1997. 

26 Final BACM Technological and Economic Feasibility Analysis, SJVAPCD 2003 PM10 SIP, April 2003. 27.Final BACM Technological and Economic Feasibility Analysis, SJVAPCD 2003 PM10 SIP, April 2003, and 

SCAQMD, Rule 403 Final Staff Report, Appendix G, February 1997 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

D R A F T F I N A L E N V I R O N -42- 

illegal OHV use. There will also be reductions resulting from implementation of the BLM dust 

control plan of episodic emissions from legal OHV events.) 

Estimated costs for PR 804-related controls include: dust suppressants ($3,340 per acre); and 

signage ($200 per sign).28 

PR 805: Paved and Unpaved Roads

PR 805 applies to unpaved paved roads. Of the 7,813 miles of unpaved roads in Imperial County, 

1362 miles are city and county roads, 6312 miles are canal roads, and 139 miles are federal roads 

(BLM and USFS). 25.5% of entrained emissions and 5% of windblown emissions are estimated to 

come from city and county roads over 50 ADT, which total 217 miles. Canal roads in total are 

estimated to contribute 67% of the windblown emissions and 53% of the entrained emissions. It is 

assumed that 0.5% of canal roads (31.5 miles) have 20 ADT or greater, and would thus be subject to 

PR 805. For the purposes of this analysis, no reductions are credited to federal roads, although 

there will be reductions based on the BLM dust control plan (PAR 800). Total applicability for 

non-farm roads is thus 5% for windblown and 26% for entrained dust, resulting in an overall 

applicability percentage of 20%. (See also “Determination of PR 805 Applicability” spreadsheet in 

Appendix B.) The composite control factor (entrained and windblown) is estimated to be 60%29, 

assuming that both the County and IID will choose gravelling to meet the requirements of PR 805. 

(Emission reductions will increase if paving is chosen as the control option, but budget analysis 

indicates that paving an appreciable number of miles is not fiscally feasible.) Overall reductions 

from PR 805 are estimated at 10.09 tons/day. 

Imperial County Public Works Department has provided the following cost information for the 

paving or gravelling of high ADT roads30. They estimate that it would cost $2,980 to apply dust 

suppressant to 1 mile of unpaved road, $8,950 to gravel, grade, compact and water 1 mile of 

unpaved road, and $131,200 to pave 1 mile of unpaved road. It is the County’s current intention to 

comply with PR 805 by gravelling 10% of the applicable roads per year (~22 miles per year). The 

annual cost of complying with PR 805 is thus approximately $194,000 per year. (Paving those 

same roads would cost approximately $2,850,000.) The Imperial County Public Works Department 

has also provided additional budget information.31 The Department has budgeted $316,000 for 

gravelling projects in FY2005-06.; this is based on a 1997 FEMA project that entailed four road 

improvement (e.g. graveling) contracts for 550 miles of unpaved roads at a cost of $9.5 million. 

The current budget for paved road maintenance is $2 million per year. In addition, the Department 

has purchased six traffic counters at a cost of $1,240, to conduct additional traffic counts on 

unpaved roads in the county. 

PR 806: Conservation Management Practices

PR 806 requires CMPs at all farms over 40 acres, which includes over 90% of farm acreage in 

Imperial County. Thus, the applicability is 90%. San Joaquin Valley estimated emission reductions 

from Rule 4550, which is functionally equivalent to PR 806, by CMP and crop category. In 

addition to assuming an 80% rule compliance factor, information used to calculate the emission 

reductions included an estimate of which CMP options would be used for each crop type and CMP 

 

28 Both from Final BACM Technological and Economic Feasibility Analysis, SJVAPCD 2003 PM10 SIP, April 2003. 29 Based on control efficiency cited in San Joaquin Valley’s Final Draft Staff Report for Regulation VIII (May 2004). 

30 Imperial County Public Works cost estimate of compliance, August 1, 2005. 

31 Imperial County Public Works Department letter to ICAPCD, dated August 22, 2005. 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

D R A F T F I N A L E N V I R O N -43- 

category. That information is not available for Imperial County at this time. For purposes of 

estimating emission reductions for this report, it is assumed that a composite control factor derived 

from dividing Rule 4550 emission reductions by emissions for each source category can be applied 

to Imperial County. (The Rule 4550 staff analysis assumed that the rule applied 91% of San 

Joaquin Valley farms, compared to 90% of Imperial County farms subject to PR 805. That 

difference was accounted for in determining PR 806 emission reductions.) Overall reductions from 

PR 806 are estimated at 4.16 tons/day. 

Costs for CMPs related to unpaved roads and traffic areas would be similar to control costs 

presented for PR 803 (track-out controls) and PR 805 (unpaved road / traffic area controls). Costs 

for CMPs for land preparation / cultivation and harvesting are highly dependent on crop type and 

the specific CMP option chosen. SJVAPCD32 cites cost information was received from the 

University of California Cooperative Extension, UC Davis and ARB (various documents), Draft 

Regulation VIII Staff Report dated September 2001, the 2003 PM10 Plan, inputs from UC Davis 

Cooperative Extension, inputs from stakeholders, and NRCS/RCD, and internet research. 

SJVAPCD determined33 that for San Joaquin Valley farmers that “(t)he cost effectiveness analysis 

demonstrates a savings when reducing the number of passes for the Land Preparation CMP 

Category. It also shows some potential savings in the Harvest CMP Category. For the other CMP 

categories, the analysis generally shows a net cost.” 

Cost-Effectiveness 

The cost-effectiveness of the measures in each Regulation VIII rule is presented in Tables 5-2 

though 5-7. These estimates of cost-effectiveness for the individual control measures in Regulation 

VIII are based on the 2004 CARB staff report34 for SB 656 and the 2003 San Joaquin Valley PM10

SIP35. Actual cost-effectiveness estimates for controls in Imperial County are expected to be the 

same or less cost-effective than those listed in the tables. Based on the rural nature of Imperial 

County, it would be expected that the emission reductions associated with these measures will be 

the same or smaller than those assumed in San Joaquin Valley and other areas. For example, 

activity levels associated with emissions (e.g., VMT for paved roads, ADVT for unpaved roads) 

will be lower in Imperial County than other areas, resulting in less emissions (and emission 

reductions) for these sources. Control costs in Imperial County may also be higher in some cases. 

More current information is available for Rule 805 implementation on county roads. Based on 

information from Imperial County’s Public Works Department,36 assuming that 10% of the 

217miles of applicable high ADT roads are treated per year for ten years, and a 4% interest rate, the 

cost-effectiveness of PR 805 for county roads is approximately $795/ton. (The cost-effectiveness of 

paving would be approximately $7,100/ton, but the absolute cost ($2,850,000) is greater than the 

entire paved and unpaved road maintenance budget for Imperial County). These estimates are 

comparable to estimates in the SB 656 staff report ($344/ton to $12,300/ton for stabilizing, 

 

32 Final BACM Technological and Economic Feasibility Analysis, SJVAPCD 2003 PM10 SIP, April 2003 and Appendix 

B, Rule 4550 Final Staff Report, SJVAPCD, April 15, 2004. 

33 Appendix B, Rule 4550 Final Staff Report, SJVAPCD, April 15, 2004. 

34 CARB Staff Report, Proposed List of Measures to Reduce Particulate Matter – PM10and PM2.5 (Implementation of 

Senate Bill 656, Sher 2003), October 18, 2004. 

35 SJVAPCD 2003 PM10 SIP, Appendix G, BACM/T and RACM/T Demonstration for Sources of PM10 and PM10

Precursors in the San Joaquin Valley Air Basin, SJVAPCD, April 2003. 

36 Imperial County Public Works cost estimate of compliance, August 1, 2005. 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

D R A F T F I N A L E N V I R O N -44- 

gravelling and paving)37 and in other non-attainment area BACM analyses ($2,100/ton to 

$5,900/ton for paving in the San Joaquin Valley)38. 

Certain dust control measures, as identified in Senate Bill 656, are not included in proposed 

Regulation VIII amendments based on technical reasons such as the source is not present (e.g., 

winter non-skid sand) or the control cannot be applied effectively in Imperial County (e.g. PM10-

certified sweepers). These measures are identified in Table 5-8. No potential BACM measures 

have been excluded based on cost-effectiveness, although a cost-effectiveness analysis of PR 805 

provisions for unpaved parking lots and other traffic areas is being conducted. 

 

37 CARB Staff Report, Proposed List of Measures to Reduce Particulate Matter – PM10and PM2.5 (Implementation of 

Senate Bill 656, Sher 2003), October 18, 2004. 

38 Final BACM Technological and Economic Feasibility Analysis, SJVAPCD 2003 PM10 SIP, April 2003. 
Technical Memorandum: Regulation VIII BACM Analysis 

D R A F T F I N A L -45- Table 5-2. Cost-effectiveness of measures in Proposed Rule 801 – Construction and Demolition NOTE: Construction and demolition source categories are below the DM level. 

PR 801 SB 656 Measure No. SB 656 ($/ton) SJ

E.1.a-b Limit VDE to 20% opacity for sites of > 1 acre 24-26.a Watering $301/ton See below F1.a. Pre-Activity: Pre-water site and phase work to reduce amount of distributed surface area F1.b 

During Active Operation: apply water or chemical stabilizer; or construct and maintain a wind barrier 

F.1.b.3 

Apply water or chemical stabilizer to unpaved haul/access roads and unpaved vehicle/equipment traffic areas 

F.1.c 

Periods of Inactivity: restrict vehicular access; and apply water or chemical stabilizer. If area > 

0.5 acres of disturbed surface area remains unused for 3 7 days, area must comply with conditions for stabilized surface area 

24-26.b, 

39, and 40 

RACM to BACM upgrade: $197/ton [NOTE: based on SCAQMD minor upgrades. Not appropriate comparison] 

Apply watsuppressan$7,222,000Prohibit Dwind>25 mDust Moni$231,000-12% soil m$21,600-$515 mph spposting of $74,600/toDust Contr$31,500/toRequire nooperations 
Technical Memorandum: Regulation VIII BACM Analysis 

D R A F T F I N A L -46- Table 5-3. Cost-effectiveness of measures in Proposed Rule 802 – Bulk Materials NOTE: Bulk materials source categories are below the DM level. 

PR 802 SB 656 Measure No. SB 656 ($/ton) S

E Limit VDE to 20% opacity for bulk material handling, material transport, and haul trucks 28.a $1,151/ton (handling) to $28,293/ton (storage) None RF.1.a Spray with water prior F.1.b Apply and maintain chemical stabilizer 28.b and 41a. RACM to BACM upgrade: $197/ton F.1.c Protect from wind erosion by sheltering or enclosing the operation and transfer line 28.a See 28.a. above F.1.d Cover bulk materials stored outdoors with tarps, plastic, or other material 28.a See 28.a. above 

Require enclosu$659,0

F.2.a Completely cover or enclose all Haul Truck loads of Bulk Material 28.a See 28.a. above F.2.b, c, d Material transport: cover, freeboard, housekeeping 28.b See 28.b. above 
Technical Memorandum: Regulation VIII BACM Analysis 

D R A F T F I N A L -47- Table 5-4. Cost-effectiveness of measures in Proposed Rule 803 – Track-out and Carry-out NOTE: Track-out and carry-out source categories are below the DM level.

PR 803 SB 656 Measure No. SB 656 ($/ton) SJ

F.1.a 

Rapidly clean up any bulk material tracked out or carried out onto a paved road surface by the end of the day 

29-30 

Manual Sweeping: $3,54/tonControl devices installed at access points to public roads: $13,700 to $322,000/ton Length of paved interior roads: $7,930 to $186,000/ton 

All sites with access to a paved road and with > 150 ADT, or > 20 ADT by vehicles with > 3 axles shall: 

F.1.b Install one or more Track-Out Prevention Devices or wash down system at access points; or F.1.c 

Apply and maintain paving, chemical stabilization, or gravel for a distance of 50 or more consecutive feet at access points 

29.b <$100/ton 

Impose Ru$44,100-$Require trabe 25 ft lon$13,700-$Require pa100 ft long $7,930-$1Gravel pad
Technical Memorandum: Regulation VIII BACM Analysis 

D R A F T F I N A L -48- Table 5-5. Cost-effectiveness of measures in Proposed Rule 804 – Open Areas NOTE: Open areas source categories are above the DM level.

PR 804 SB 656 Measure No. SB 656 ($/ton) SJ

E.1 Limit open areas to VDE of 20% opacity 31.a Watering: $7020/ton E.2 

Prevent unauthorized vehicle access by posting "No Trespassing" signs or installing physical barriers such as fences, gates, posts, and/or appropriate barriers to prevent access 

31.a Watering: $7,020/ton None Repo

F.1.a Apply and maintain water or dust suppressant to all undefeated areas F.1.b Establish vegetation on all previously disturbed 

areas 

F.1.c Pave, apply and maintain gravel or apply and maintain chemical stabilizers/suppressants 

27, 31, and 42

27b. RACM to BACM upgrade: $197/ton 31a. Watering: $7,020/ton 31b. RACM to BACM upgrade: $197/ton 42. $697/ton 

Impose Ruurban parcthat have a disturbed sImpose Ruimmediatedisturbanc
Technical Memorandum: Regulation VIII BACM Analysis 

D R A F T F I N A L -49- Table 5-6. Cost-effectiveness of measures in Proposed Rule 805 – Paved and Unpaved Roads NOTE: The unpaved roads source category is above the DM level.

 PR 805 – Unpaved Roads SB 656 Measure No. SB 656 ($/ton) SJ

F.1.a Pave or F.1.b Apply chemical stabilizers or F.1.c 

Apply and maintain gravel, recrushed/recycled 

asphalt or other material of low silt content to a depth of > 3 inches or 

F.1.d Apply water one or more time daily or F.1.F Permanent road closure or F.1.f 

Any other method to meet VDE of 20% opacity and meets conditions of a stabilized unpaved road 

35-36 

35. Apply water, gravel, chemical or dust suppressant, or pave: $344 to $12,293/ton36a. -Apply water, dust suppressant, gravel, pave: $56 to $1,481/ton -Paving: $2,160 to $5,920/ton 36b. $958/ton 

Limit speeRequire ropaved: $2,Impose Ru

F.2.a through g Canal Roads measures None Not Estimated None RepoUnpaved Traffic Areas F.3.a Pave or F.3.b Apply chemical stabilizers or F.3.c 

Apply and maintain gravel, recrushed/recycled 

asphalt or other material of low silt content to a depth of 3 3 inches or 

F.3.d Apply water one or more time daily 

35-36 See 35-36 above See 35-36 
Technical Memorandum: Regulation VIII BACM Analysis 

D R A F T F I N A L -50- Table 5-6. Cost-effectiveness of Measures in Proposed Rule 805 – Paved and Unpaved Roads (continued) NOTE: The paved road source category is below the DM level.

 PR 805 – New and Modified Paved Roads SB 656 Measure No. SB 656 ($/ton) SJ

F.4.1 

New or modified paved roads with projected ADT > 500 vehicles shall construct paved shoulders of 4 ft (500-3000 vehicle trips) or 8 ft (> 3000 vehicle trips)

32 

F.4.2 

In lieu of F.4.1, a curbing adjacent to and contiguous with the travel lane or paved shoulder or road may be constructed 

32 

F.4.3 

In lieu of F.4.1, intersections, auxiliary entry lanes and auxiliary exit lanes may be constructed adjacent to and contiguous with the roadway 

32 

F.4.4 

Medians shall be constructed with paved shoulders having a minimum width of 4 ft. adjacent to traffic lanes for projects ADT > 500, unless speed limit < 45 mph with curbing or landscaped medians 

32 

F.6 In lieu of paving or vegetation requirement, may apply oils or other chemical stabilizers 32 

32a. 4 ft. Paved shoulder on 50% of highest ADT existing paved roads: $7,290-$11,300/ton 32b. Curb and Gutter road shoulder: $5577/ton 

4ft pavenew/modif$508,000/t4ft paved ADT exist$11,300/toRequire 

deposition 24 hrs: $2,
Technical Memorandum: Regulation VIII BACM Analysis 

D R A F T F I N A L -51- Table 5-7. Cost-effectiveness of measures in Proposed Rule 806 – Conservation Management Practices NOTE: Some agricultural operations source categories (eg. tilling and windblown) are above the DM level.

 PR 806 SB 656 Measure No. SB 656 ($/ton) SJ

D.1 

Shall implement at least one of the following practices if own/operate a commercial farm of > 40 acres: land preparation and cultivation; harvest activities; unpaved roads; or unpaved equipment operation yards. 

D.4 Prepare and submit a CMP application for each agricultural operation site 

43.b 

Highwind tilling prohibition and stabilization of fallow fields: $134/ton 

E.1 Land Preparation and Cultivation 43.c $8/ton E.2 Harvesting 43.b None provided E.3 Unpaved Farm Roads 43.a and d $958/ton E.4 Equipment Traffic Areas 43.d $958/ton 

Overall: $8 to $2,50
Technical Memorandum: Regulation VIII BACM Analysis 

D R A F T F I N A L -52- 

Table 5-8 Senate Bill 656 Measures Not in the Proposed Regulation VIII Amended Rules 

SB656 Cost-Effectiveness 

Comment 

33 Requires use of certified PM10 efficient street 

$1,119/ton (1996$) A Rule 1186-certified sweeper is $37,000 more expensive than a conventional sweeper. 

As noted in the SJVUAPCD “BACM/BACDemonstration for Sources of PM10 and PM

Joaquin Valley Air Basin,” (dated April 28will result in safety problems on freeways aThe overwhelming majority of roads in Impand rural roads in flat terrain. For maximum travel less than 5 mph. 

34 

Requires vacuum-street sweeping on roads to remove sand and cinders that are placed on the road during winter storms as an anti-skid material. . 

$350/ton (1996$) (assumes 2,400 lb/day winter-day emission reductions) 

This Great Basin Unified APCD measure dCounty, where anti-skid material is not use

37a. 

and 

37b. 

Weed Abatement Activities Pre-activity Requirements: 1) Prewatering to limit VDE opacity to 20%; or 2) phasing work to reduce amount of disturbed surface area. Apply water during active operations to limit VDE to 20% opacity. Apply water or chemical stabilizers to meet conditions of stabilized surface. 

Not estimated Emissions from this source are not quantifi

38 Defines windblown dusts NA No specific requirements. 

41b. 

Additional bulk material control requirements for Coachella Valley source 

$352 - $462 /ton (1992 $) Controls specific to Coachella Valley blow

exist in Imperial County. 
Technical Memorandum: Regulation VIII BACM Analysis October 2005 

D R A F T F I N A L -58- E N V I R O N 

6. CONCLUSIONS 

This report presents the BACM determination based on proposed Regulation VIII amendments. 

It includes all elements of a BACM determination, including inventory assessment, calculation 

of the de minimis emission level, identification of significant sources (e.g. those sources which 

emit more than the DM level), a comparative analysis of proposed Regulation VIII amendments 

for significant sources with regulations adopted by serious PM10 non-attainment areas, and a 

presentation of cost-effectiveness of the dust control measures. The proposed Regulation VIII 

BACM amendments are based on BACM recently adopted by other serious non-attainment 

areas. This technical memorandum presented the existing inventory of primary PM10 sources 

and determined the de minimis level of primary PM10 for Imperial County, based on that 

inventory and recent ambient PM10 levels. Based on the calculated DM level of 4.9 tons/day of 

PM10, significant sources of primary PM10 in Imperial County were identified. Those sources are 

unpaved road and surface dust, disturbed open areas, and certain agricultural sources. A 

comparative analysis of the proposed Regulation VIII amendments and other BACM rules in 

serious PM10 non-attainment areas was presented. This comparative analysis was done for both 

significant sources and sources below the DM level. For significant sources, a discussion of the 

stringency of threshold limits and requirements compared to the most stringent in other serious 

non-attainment areas was presented, including justification of less stringent thresholds and/or 

requirements, if necessary. Emission reductions and costs associated with each proposed rule 

were presented. Except for unpaved parking lots and staging areas, proposed Regulation VIII 

thresholds and requirements were demonstrated to be as stringent as the most stringent adopted 

in other serious PM10 non-attainment areas. Further cost-effectiveness analysis will be 

conducted for unpaved parking lots and staging areas. Imperial County will propose 

amendments to PR 805 reflecting more stringent threshold and requirements if they are shown to 

be cost –effective. Emission reduction, cost information, and cost-effectiveness estimates for the 

proposed Regulation VIII rules and/or control measures in the proposed Regulation VIII rules 

were presented. Cost-effectiveness estimates for control measures not included in Regulation 

VIII were also presented. No potential BACM measures were excluded based on costeffectiveness. Except for unpaved traffic areas (for which the cost-effectiveness justification of 

thresholds and requirements has not been completed), Proposed Regulation VIII amendments for 

sources above the DM level have been determined to be BACM for Imperial County, based on 

comparative analysis with fugitive dust rules in serious non-attainment areas. Measures 

excluded from proposed Regulation VIII have been excluded for technical or implementation 

reasons, not cost-effectiveness.