Enclosure 1 

Arizona Revised Statutes §§49-104 and 49-404 
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49-104. Powers and duties of the department and director

A. The department shall: 

1. Formulate policies, plans and programs to implement this title to protect the environment. 

2. Stimulate and encourage all local, state, regional and federal governmental agencies and all private 

persons and enterprises that have similar and related objectives and purposes, cooperate with those 

agencies, persons and enterprises and correlate department plans, programs and operations with those 

of the agencies, persons and enterprises. 

3. Conduct research on its own initiative or at the request of the governor, the legislature or state or 

local agencies pertaining to any department objectives. 

4. Provide information and advice on request of any local, state or federal agencies and private persons 

and business enterprises on matters within the scope of the department. 

5. Consult with and make recommendations to the governor and the legislature on all matters 

concerning department objectives. 

6. Promote and coordinate the management of air resources to assure their protection, enhancement 

and balanced utilization consistent with the environmental policy of this state. 

7. Promote and coordinate the protection and enhancement of the quality of water resources consistent 

with the environmental policy of this state. 

8. Encourage industrial, commercial, residential and community development that maximizes 

environmental benefits and minimizes the effects of less desirable environmental conditions. 

9. Assure the preservation and enhancement of natural beauty and man-made scenic qualities. 

10. Provide for the prevention and abatement of all water and air pollution including that related to 

particulates, gases, dust, vapors, noise, radiation, odor, nutrients and heated liquids in accordance with 

article 3 of this chapter and chapters 2 and 3 of this title. 

11. Promote and recommend methods for the recovery, recycling and reuse or, if recycling is not 

possible, the disposal of solid wastes consistent with sound health, scenic and environmental quality 

policies. 

12. Prevent pollution through the regulation of the storage, handling and transportation of solids, liquids 

and gases that may cause or contribute to pollution. 

13. Promote the restoration and reclamation of degraded or despoiled areas and natural resources. 

14. Assist the department of health services in recruiting and training state, local and district health 

department personnel. 

15. Participate in the state civil defense program and develop the necessary organization and facilities to 

meet wartime or other disasters. 

16. Cooperate with the Arizona-Mexico commission in the governor's office and with researchers at 

universities in this state to collect data and conduct projects in the United States and Mexico on issues 

that are within the scope of the department's duties and that relate to quality of life, trade and economic 

development in this state in a manner that will help the Arizona-Mexico commission to assess and 

enhance the economic competitiveness of this state and of the Arizona-Mexico region. 

B. The department, through the director, shall: 

1. Contract for the services of outside advisers, consultants and aides reasonably necessary or desirable 

to enable the department to adequately perform its duties. 

2. Contract and incur obligations reasonably necessary or desirable within the general scope of 

department activities and operations to enable the department to adequately perform its duties. 

3. Utilize any medium of communication, publication and exhibition when disseminating information, 

advertising and publicity in any field of its purposes, objectives or duties. 

4. Adopt procedural rules that are necessary to implement the authority granted under this title, but that 

are not inconsistent with other provisions of this title. 

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5. Contract with other agencies including laboratories in furthering any department program. 

6. Use monies, facilities or services to provide matching contributions under federal or other programs 

that further the objectives and programs of the department. 

7. Accept gifts, grants, matching monies or direct payments from public or private agencies or private 

persons and enterprises for department services and publications and to conduct programs that are 

consistent with the general purposes and objectives of this chapter. Monies received pursuant to this 

paragraph shall be deposited in the department fund corresponding to the service, publication or 

program provided. 

8. Provide for the examination of any premises if the director has reasonable cause to believe that a 

violation of any environmental law or rule exists or is being committed on the premises. The director 

shall give the owner or operator the opportunity for its representative to accompany the director on an 

examination of those premises. Within forty-five days after the date of the examination, the department 

shall provide to the owner or operator a copy of any report produced as a result of any examination of 

the premises. 

9. Supervise sanitary engineering facilities and projects in this state, authority for which is vested in the 

department, and own or lease land on which sanitary engineering facilities are located, and operate the 

facilities, if the director determines that owning, leasing or operating is necessary for the public health, 

safety or welfare. 

10. Adopt and enforce rules relating to approving design documents for constructing, improving and 

operating sanitary engineering and other facilities for disposing of solid, liquid or gaseous deleterious 

matter. 

11. Define and prescribe reasonably necessary rules regarding the water supply, sewage disposal and 

garbage collection and disposal for subdivisions. The rules shall: 

(a) Provide for minimum sanitary facilities to be installed in the subdivision and may require that water 

systems plan for future needs and be of adequate size and capacity to deliver specified minimum 

quantities of drinking water and to treat all sewage. 

(b) Provide that the design documents showing or describing the water supply, sewage disposal and 

garbage collection facilities be submitted with a fee to the department for review and that no lots in any 

subdivision be offered for sale before compliance with the standards and rules has been demonstrated by 

approval of the design documents by the department. 

12. Prescribe reasonably necessary measures to prevent pollution of water used in public or semipublic 

swimming pools and bathing places and to prevent deleterious conditions at such places. The rules shall 

prescribe minimum standards for the design of and for sanitary conditions at any public or semipublic 

swimming pool or bathing place and provide for abatement as public nuisances of premises and facilities 

that do not comply with the minimum standards. The rules shall be developed in cooperation with the 

director of the department of health services and shall be consistent with the rules adopted by the 

director of the department of health services pursuant to section 36-136, subsection H, paragraph 10. 

13. Prescribe reasonable rules regarding sewage collection, treatment, disposal and reclamation systems 

to prevent the transmission of sewage borne or insect borne diseases. The rules shall: 

(a) Prescribe minimum standards for the design of sewage collection systems and treatment, disposal 

and reclamation systems and for operating the systems. 

(b) Provide for inspecting the premises, systems and installations and for abating as a public nuisance 

any collection system, process, treatment plant, disposal system or reclamation system that does not 

comply with the minimum standards. 

(c) Require that design documents for all sewage collection systems, sewage collection system 

extensions, treatment plants, processes, devices, equipment, disposal systems, on-site wastewater 

treatment facilities and reclamation systems be submitted with a fee for review to the department and 

may require that the design documents anticipate and provide for future sewage treatment needs. 

(d) Require that construction, reconstruction, installation or initiation of any sewage collection system, 

sewage collection system extension, treatment plant, process, device, equipment, disposal system, onsite wastewater treatment facility or reclamation system conform with applicable requirements. 

14. Prescribe reasonably necessary rules regarding excreta storage, handling, treatment, transportation 

and disposal. The rules shall: 

(a) Prescribe minimum standards for human excreta storage, handling, treatment, transportation and 

disposal and shall provide for inspection of premises, processes and vehicles and for abating as public 

nuisances any premises, processes or vehicles that do not comply with the minimum standards. 

(b) Provide that vehicles transporting human excreta from privies, septic tanks, cesspools and other 

treatment processes shall be licensed by the department subject to compliance with the rules. 

15. Perform the responsibilities of implementing and maintaining a data automation management system 

to support the reporting requirements of title III of the superfund amendments and reauthorization act 

of 1986 (P.L. 99-499) and title 26, chapter 2, article 3. 

16. Approve remediation levels pursuant to article 4 of this chapter. 

C. The department may charge fees to cover the costs of all permits and inspections it performs to 

insure compliance with rules adopted under section 49-203, subsection A, paragraph 6, except that state 

agencies are exempt from paying the fees. Monies collected pursuant to this subsection shall be 

deposited in the water quality fee fund established by section 49-210. 

D. The director may: 

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1. If he has reasonable cause to believe that a violation of any environmental law or rule exists or is 

being committed, inspect any person or property in transit through this state and any vehicle in which 

the person or property is being transported and detain or disinfect the person, property or vehicle as 

reasonably necessary to protect the environment if a violation exists. 

2. Authorize in writing any qualified officer or employee in the department to perform any act that the 

director is authorized or required to do by law. 

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49-404. State implementation plan

A. The director shall maintain a state implementation plan that provides for implementation, 

maintenance and enforcement of national ambient air quality standards and protection of visibility as 

required by the clean air act. 

B. The director may adopt rules that describe procedures for adoption of revisions to the state 

implementation plan. 

C. The state implementation plan and all revisions adopted before September 30, 1992 remain in effect 

according to their terms, except to the extent otherwise provided by the clean air act, inconsistent with 

any provision of the clean air act, or revised by the administrator. No control requirement in effect, or 

required to be adopted by an order, settlement agreement or plan in effect, before the enactment of the 

clean air act in any area which is a nonattainment or maintenance area for any air pollutant may be 

modified after enactment in any manner unless the modification insures equivalent or greater emission 

reductions of the air pollutant. The director shall evaluate and adopt revisions to the plan in conformity 

with federal regulations and guidelines promulgated by the administrator for those purposes until the 

rules required by subsection B are effective. 

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Enclosure 2 

State Implementation Plan Completeness Checklist 
STATE IMPLEMENTATION PLAN COMPLETENESS CHECKLIST 

Submittal of 

Revision to the Arizona State Implementation Plan 

Agricultural Best Management Practices 

April 2010 

1. SUBMITTAL LETTER FROM GOVERNOR/DESIGNEE 

 

Included 

2. EVIDENCE OF ADOPTION 

See submittal letter. 

3. STATE LEGAL AUTHORITY FOR ADOPTION/IMPLEMENTATION 

See Enclosure 1. 

4. COMPLETE COPY OF STATUTE/REGULATION/DOCUMENT 

 See Enclosure 3. 

5. WRITTEN SUMMARY OF RULE/RULE CHANGE 

 See Enclosure 3. 

6. RULE CHANGES INDICATED BY UNDERLINING AND CROSS-OUTS 

 Not applicable. 

7. EVIDENCE THAT ARIZONA ADMINISTRATIVE PROCEDURE ACT REQUIREMENTS 

WERE MET FOR RULE/PLAN 

 See Enclosure 3. 

8. EVIDENCE OF PUBLIC HEARING PER 40 CFR 51.102 

 See Enclosure 3. 

9. PUBLIC COMMENTS AND AGENCY RESPONSE 

 See Enclosure 3. 

 

10. IDENTIFICATION OF POLLUTANTS REGULATED BY RULE/PLAN 

This State Implementation Plan revision pertains to emissions of PM10. 

 
11. IDENTIFICATION OF SOURCES/ATTAINMENT STATUS 

See Enclosure 3. 

 

12. RULE’S/PLAN’S EFFECT ON EMISSIONS 

 See Enclosure 3. 

13. DEMONSTRATION THAT NAAQS, PSD INCREMENTS AND RFP ARE PROTECTED 

 See Enclosure 3. 

14. MODELING SUPPORT 

 See Enclosure 3. 

15. EVIDENCE THAT EMISSIONS LIMITATIONS ARE BASED ON CONTINUOUS 

EMISSIONS REDUCTION TECHNOLOGY 

 Not applicable. 

16. IDENTIFICATION OF RULE SECTIONS CONTAINING EMISSION LIMITS, WORK 

PRACTICE STANDARDS, AND/OR RECORD KEEPING/REPORTING REQUIREMENTS 

 Not applicable. 

 

17. COMPLIANCE/ENFORCEMENT STRATEGIES 

Not applicable. 

18. ECONOMIC TECHNICAL JUSTIFICATION FOR DEVIATION FROM U.S. 

ENVIRONMENTAL PROTECTION AGENCY (EPA) POLICIES 

 No known deviation from EPA policy. 
Enclosure 3 

Final Revision to the Arizona State Implementation Plan 

Maricopa County PM10 Serious Nonattainment Area 

Agricultural Best Management Practices 
Arizona State Implementation Plan 

Maricopa County PM10 

Serious Nonattainment Area 

Agricultural Best Management Practices 

 

 Air Quality Division 

 April 2010
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1
TABLE OF CONTENTS

EXECUTIVE SUMMARY .............................................................................................................4 

CHAPTER 1.0 INTRODUCTION ...............................................................................................6 

 1.1 Physical and Meteorological Description of the Maricopa County PM10 Serious 

Nonattainment Area...................................................................................................6 

 1.2 The Maricopa County PM10 Nonattainment Area History ........................................8 

 1.3 Maricopa Association of Governments (MAG) 2007 Five Percent Plan for PM10

for the Maricopa County Nonattainment Area ........................................................10 

 1.4 Agricultural Best Management Practices SIP Revision...........................................13 

 

CHAPTER 2.0 AGRICULTURAL BEST MANAGEMENT PRACTICES SELECTION 

PROCESS ..........................................................................................................14 

 2.1 Actions of the Governor’s Agricultural Best Management Practices Committee...14 

 2.2 Senate Bill 1552 and Committee Actions................................................................15 

 

CHAPTER 3.0 ADDITIONAL AGRICULTURAL BEST MANAGEMENT PRACTICES ...18 

 3.1 Best Management Practices .....................................................................................18 

 3.1.1 Cessation of Night Tillage on High Pollution Advisory Days ..................18 

 3.1.2 Green Chop ................................................................................................18 

 3.1.3 Integrated Pest Management......................................................................18 

 3.1.4 Precision Farming ......................................................................................19 

 3.1.5 Transgenic Crops ...................................................................................... 19 

 3.2 Emissions Reductions from Revisions to the BMP Program ..................................19 

 3.2.1 Number of BMPs Required Per Agricultural Category.............................20 

 3.2.2 Cessation of Night Tilling..........................................................................20 

 3.2.3 Extension of the Agricultural BMP Program to the Maricopa County 

 Portion of Area A.......................................................................................20 

 3.3 Conclusion ...............................................................................................................21 

CHAPTER 4.0 OUTREACH......................................................................................................22 

 3.1 Public Outreach Activities .......................................................................................22 

 

CHAPTER 5.0 CONCLUSION..................................................................................................24 

 

LIST OF FIGURES 

CHAPTER 1.0 

Figure 1: Maricopa County PM10 Nonattainment Area..................................................................7 

Figure 2: Annual 2005 PM10 Emissions in the PM10 Nonattainment Area ..................................12 

CHAPTER 2.0 

Figure 3: Map of PM10 Nonattainment Area and Area A.............................................................16 

2
LIST OF APPENDICES 

APPENDIX A (AgBMP Rule) 

APPENDIX B (Technical Support) 

APPENDIX C (Booklet and Pocket Guide) 

APPENDIX D (Public Process) 

3
EXECUTIVE SUMMARY 

The purpose of this State Implementation Plan (SIP) revision is to address the contribution from 

agricultural practices to the Maricopa County Nonattainment area for particulate matter 

pollution. The Maricopa County PM10 Serious Nonattainment area encompasses the Phoenix 

metropolitan area and the surrounding cities. The area has remained in violation of the federal 

health standards for particulate matter of 10 microns or less (PM10) emissions since the standard 

was adopted in 1987. To address the problem numerous emission control programs have been 

adopted. Among the many sources of PM10 emissions contributing to nonattainment, agricultural 

activities have been required to be subject to controls. On August 4, 1997, the Environmental 

Protection Agency (EPA) approved in part the Plan for Attainment of the 24-hour PM10 Standard 

– Maricopa County PM10 Nonattainment Area and disapproved the demonstrations for several 

source categories of PM10, including agricultural sources. In order to address agricultural 

sources of PM10, the Arizona Legislature created the Governor’s Agricultural Best Management 

Practices Committee (Committee) in 1998 to develop requirements of an agricultural general 

permit and alternative best management practices (BMPs) for controlling dust. 

Arizona has made several submittals to address the Clean Air Act (CAA) requirements for 

serious PM10 nonattainment area plans in the Phoenix area. These include documents submitted 

by the Arizona Department of Environmental Quality (ADEQ) and the Maricopa Association of 

Governments (MAG). The EPA views these submittals collectively as the full serious area PM10

plan for the Phoenix area, with the Revised Maricopa Association of Governments 1999 Serious 

Area Particulate Plan for PM-10 for the Maricopa County Nonattainment Area as the primary 

document (67 FR 48718). Parts of the 1999 plan were approved by EPA on July 25, 2002, and 

the attainment deadline was extended to December 31, 2006. The nonattainment area was 

unable to reach attainment by this extended deadline, which subjected the area to Clean Air Act 

requirements stipulating that PM10 emissions in the nonattainment area be reduced by five 

percent per year until the PM10 standard is attained. To address agricultural sources of PM10

emissions and contribute to the required five percent reductions, the Committee adopted new 

agricultural BMPs to reduce PM10 emissions from agricultural activities. Senate Bill (SB) 1552 

also addressed agricultural sources of PM10 by requiring the use of two BMPs per agricultural 

category and expanding the applicable area of BMPs to include the Maricopa County portions of 

Area A. 

This document revises the Agricultural Best Management Practices, Maricopa County PM10

Serious Area State Implementation Plan submitted in 2001, to reflect additional BMPs, an 

increase in the number of required BMPs from one to two per agricultural category, and an 

extended area of implementation. Chapter 1.0 contains a brief history of the nonattainment area. 

Chapter 2.0 contains a description of the review and analysis process used by the Committee and 

the results of this process. Descriptions of the BMPs adopted by the Committee are included in 

Chapter 3.0. Chapter 4.0 contains a description of the public outreach activities that were held to 

inform the agricultural community of the changes to the BMP Program. 

With this submittal, ADEQ requests that EPA approve this SIP Revision to the 2001 Agricultural 

Best Management Practices, Maricopa County PM10 Serious Area State Implementation Plan. 

4
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5
6

CHAPTER 1.0 INTRODUCTION 

The Maricopa County Planning Area has a long history of air quality challenges. Due in part to 

its location in the heart of the Sonoran Desert as well as the complexity attributed to any large 

and still growing metropolitan area, air quality has been affected by numerous sources and 

activities, both man-made and natural. This State Implementation Plan (SIP) Revision outlines 

local conditions as well as the related regulatory history for pollution from particulate matter 

(suspended particles 10 micrometers or smaller in diameter, also known as PM10) for activities in 

the Maricopa County Planning Area related to agriculture. Agricultural activities have been 

regulated in the Maricopa County Planning Area since 1998; however, the agricultural 

community continues to evaluate and commit to revise or add new practices that decrease 

concentrations of PM10 as demonstrated in this SIP Revision. 

1.1 Physical and Meteorological Description of the Maricopa County PM10 Serious 

Nonattainment Area 

The Maricopa County PM10 Serious Nonattainment Area contains portions of the municipal 

planning areas for 22 cities and towns in Maricopa County, all of the Fort McDowell, part of the 

Gila River, and all of the Salt River Pima-Maricopa Indian Communities, as well as 

unincorporated areas under the jurisdiction of Maricopa County (Figure 1). The Arizona 

Department of Environmental Quality (ADEQ) does not have the authority to require the 

implementation of controls in Indian Country, but the Tribes can implement their own controls. 

The nonattainment area also contains a 36-square mile section of Pinal County, which 

encompasses a portion of the City of Apache Junction and includes unincorporated areas under 

the jurisdiction of Pinal County. 
Figure 1: Maricopa County PM10 Nonattainment Area 
The area receives about 300 days of sunshine per year, while average annual rainfall is less than 

eight inches, with overall low humidity. Phoenix has two separate rainfall seasons. One season 

is represented by the winter months, November through March, when the Valley is subject to 

storms from the Pacific Ocean. The other rainfall season, known as the “monsoon” season, 

occurs during summer and early fall (the National Weather Service defines Arizona Monsoon 

dates as June 15 through September 30). This season is dominated by southeasterly winds 

carrying moisture from the Gulf of Mexico and thunderstorms, spawned by this moisture and 

desert heat. 

Two meteorological conditions have the potential to contribute to high concentrations of PM10: 

high winds and stagnation. Conditions for both of these events can occur in the nonattainment 

area, with high winds occurring predominantly in the spring and summer seasons, and stagnation 

occurring predominantly in the fall and winter seasons. High wind conditions are either short 

term events (less than one hour) generally a result of downdrafts from monsoon thunderstorms or 

strong pressure gradients associated with passage of a trough or cold front (usually 6-10 hours). 

Stagnation conditions are longer term events (six to 12 hours; occasionally multi-day events). 

During stagnation events, the air is very stable and has little vertical mixing. Temperature 

inversions (increasing air temperature with height) also are common during stagnation events. 

An inversion traps pollutants close to the ground, adding to any already existing concentrations 

of particulate matter. 

1.2 The Maricopa County PM10 Nonattainment Area History

In 1991, the Environmental Protection Agency (EPA) designated portions of Maricopa County 

and Pinal County as a moderate PM10 nonattainment area under the Clean Air Act (CAA) 

Amendments of 1990. The Maricopa Association of Governments (MAG) developed the 

moderate area plan, the MAG 1991 Particulate Plan for PM-10, to ADEQ, which ADEQ 

adopted and submitted to EPA on November 15, 1991. In accordance with Section 188 of the 

CAA, the deadline for the State to demonstrate attainment of the PM10 National Ambient Air 

Quality Standards (NAAQS) for this area was December 31, 1994; however, Arizona 

demonstrated to EPA that it was impracticable for this area to attain the annual PM10 NAAQS by 

the specified deadline. No demonstration was made for the 24-hour PM10 NAAQS because at 

that time an accurate assessment of the causes of the historical exceedances, which appeared to 

be highly localized, was not possible. 

On March 4, 1992, EPA determined that the plan did not meet criteria for completeness, which 

began an 18-month sanctions clock and 24-month clock to issue a moderate area PM10 Federal 

Implementation Plan (FIP) [57 FR 19906; 5/8/92]. In August 1993, MAG adopted and 

transmitted to ADEQ the MAG 1991 Particulate Plan for PM-10 for the Maricopa County Area 

and 1993 Revisions. ADEQ adopted and submitted the plan to EPA. On September 7, 1993, 

EPA determined the plan to be complete. 

In June 1994, the Arizona Center for Law in the Public Interest (ACLPI) sued to enforce the FIP 

obligation which became subject to enforcement action on March 4, 1994. EPA settled the case 
with an agreement to act on the moderate area PM10 plan by March 1, 1995 (Ober v. Browner, 

No. CIV 94-1318 PHX, PGR, Consent Decree, March 6, 1995). 

On April 10, 1995, EPA approved the Moderate Area Plan (60 FR 18010). In response to EPA’s 

approval, ACLPI filed suit (Ober v. Browner) on April 27, 1995, challenging EPA’s approval of 

Arizona’s 1991 moderate area particulate plan, due to, among other things, the plan’s failure to 

address the 24-hour PM10 NAAQS. The suit requested the Court require EPA to issue a FIP. 

Amidst the discussions and litigation concerning the approvability of the plan, EPA reclassified 

the Maricopa County PM10 Nonattainment Area to serious effective June 10, 1996, based upon 

its finding that the area failed to attain the PM10 NAAQS by the December 31, 1994, deadline 

(61 FR 21372). The action allowed Arizona 18 months to develop a new SIP providing for 

attainment of the PM10 NAAQS by December 31, 2001, the CAA attainment date for serious 

nonattainment areas (CAA § 188(c)(2)). 

On May 14, 1996, the Court of Appeals for the Ninth Circuit found that the Moderate Area Plan 

failed to address the 24-hour PM10 standard as required by the CAA [Ober v. EPA, 84 F3d 304 

(9th Cir. 1996)]. As a result, the Court mandated that EPA require "the State to submit a 

separate demonstration of the implementation of all 'reasonably available control measures’ 

targeting the 24-hour standard violations; attainment and 'reasonable further progress' for the 24-

hour standard." In September 1996, in response to the Court's mandate, EPA and ADEQ agreed 

that ADEQ would submit a "Limited" Serious Area PM10 Plan to EPA by April 18, 1997 and a 

"Full" Serious Area Plan by December 10, 1997. The limited plan would address the 24-hour 

standard violations at specific monitors and must meet the requirements for adoption and 

expedited implementation of best available control measures (BACM), all reasonably available 

control measures (RACM), and other measures as necessary to provide for reasonable further 

progress (RFP) along with expeditious attainment at those monitors. The full plan would 

represent the balance of the serious nonattainment area plan and the additional moderate area 

elements required by the Court. The full Plan titled, MAG Serious Area Committed Particulate 

Control Measures for PM10 and Support Technical Analysis, was submitted to EPA on 

December 11, 1997. 

ADEQ developed the Phoenix PM10 Microscale Field Study (Microscale Study) in 1994 to 

address the specific causes of and necessary controls for 24-hour exceedances, which was 

conducted throughout 1995 and became the basis of the limited Serious Area PM10 Plan. The 

Microscale Study addressed exceedances of the 24-hour PM10 NAAQS at four PM10 monitoring 

locations: Salt River, Maryvale, Gilbert, and West Chandler. The 24-hour exceedances at the 

Salt River site were due to fugitive dust from earth moving, industrial haul roads, unpaved 

parking lots, and unpaved roads. At the Maryvale site the exceedances were due to emissions 

from disturbed cleared areas. Exceedances at the Gilbert site were due to emissions from 

agricultural field aprons and unpaved parking lots. At the Chandler site, exceedances were due 

to emissions from agricultural fields, agricultural field aprons, vacant lots, and disturbed cleared 

areas. The SIP revision included a number of controls to address all sources of emissions with 

the exception of agriculture; as such attainment was modeled for Salt Rivers and Maryvale, but 

not for Chandler and Gilbert. 

9
ADEQ developed and submitted to EPA the limited plan titled, Plan for Attainment of the 24-

hour PM10 Standard (24-Hour Plan), on May 7, 1997. The plan showed attainment by 

committing to implement reasonable available control measures (RACM) and best available 

control measures (BACM) for the significant sources of PM10. On August 4, 1997, EPA 

approved in part and disapproved in part the 24-hour Plan (62 FR 41856). EPA approved the 

attainment demonstration at two monitoring locations (Salt River and Maryvale), and several 

county and city control measures addressing fugitive dust. EPA disapproved the RACM/BACM 

demonstrations for the monitoring locations at West Chandler and Gilbert for the sources 

categories of vacant lands, unpaved parking lots, unpaved roads, agricultural fields, and 

agricultural aprons. 

On August 3, 1998, EPA issued a FIP (63 FR 41326) addressing the moderate area PM10

requirements for the Phoenix PM10 nonattainment area. For both the annual and 24-hour PM10

standards, EPA included a demonstration that RACM would be implemented as soon as possible, 

a demonstration that it is impracticable for the area to attain the standards by the statutory 

attainment deadline, and a demonstration that RFP is being met. As part of the FIP, EPA also 

promulgated a fugitive dust rule to control PM10 emissions from vacant lots, unpaved parking 

lots and unpaved roads, and also promulgated an enforceable commitment to ensure that RACM 

for agricultural sources would be proposed by September 1999, finalized by April 2000 and 

implemented by June 2000. The FIP included a final disapproval of the RACM and attainment 

demonstration for the full Moderate Area PM10 Plan. 

To address PM10 emissions from agricultural activities, the Governor’s Agricultural Best 

Management Practices Committee (Committee) was created in 1998 by Arizona Revised Statute 

(A.R.S.) §49-457; the statute was modeled after the FIP requirement for agricultural sources. The 

Committee was charged with developing an agricultural PM10 general permit and to research and 

adopt best management practices (BMPs) for regulated agricultural activities. On September 4, 

1998, ADEQ submitted A.R.S. §49-457 to EPA for inclusion in the Arizona State 

Implementation Plan (SIP) for the Maricopa County PM10 nonattainment area as meeting the 

RACM requirements and requested that EPA approve the legislation to replace the FIP 

commitment. EPA removed the portion of the FIP for agriculture on June 29, 1999 (64 FR 

34726). ADEQ developed and submitted to EPA a SIP revision for the Maricopa County PM10

Serious Area, which included the general permit and the BMPs in July 2001. The Maricopa 

County PM10 Serious Area State Implementation Plan Revision – Agricultural Best Management 

Practices, was approved by EPA as a revision to the Arizona SIP October 11, 2001, effective 

November 13, 2001 (66 FR 51869). ACLPI filed suit in the U.S. Court of Appeals for the Ninth 

Circuit challenging, among other things, the use of BMPs as BACM. On May 10, 2004, the 

Court upheld the approval of BMPs as BACM and remanded to EPA for further consideration 

the other issues brought by the suit, Vigil v. Leavitt, 366 F.3d 1025, amended at 381 F. 3d 826 

(9th Cir. 2004). 

MAG transmitted and submitted to ADEQ the Revised MAG 1999 Serious Area Particulate Plan 

for PM-10 for the Maricopa County Nonattainment Area, which ADEQ adopted and submitted 

to EPA on February 16, 2000. This plan contained approximately seventy-seven committed 

control measures from the State and local agencies. The plan demonstrated attainment of the 

PM10 standard by December 31, 2006. On January 8, 2002, Arizona submitted revisions 

10
addressing roadways (paved and unpaved), parking areas, vacant lots, and industrial source 

emissions. 

On July 25, 2002, EPA approved the full Serious Area Particulate Matter (PM-10) Plan for the 

Maricopa County portion of the nonattainment area (67 FR 48717, effective August 25, 2002). 

The full plan is a compilation of submittals by ADEQ1, MAG2, and a number of rules.3 EPA 

approved the BACM and most stringent measure (MSM) demonstrations in the plan and granted 

the State’s request for an attainment date extension for the area. Due to continued exceedances 

of the PM10 standard, the Maricopa County PM10 Nonattainment Area was unable to meet 

attainment of the federal standard by the December 31, 2006 Clean Air Act deadline. EPA 

issued a notice regarding the failure of the Maricopa County PM10 Nonattainment Area to attain 

the PM10 NAAQS on May 25, 2007 (72 FR 31183). 

1.3 Maricopa Association of Governments (MAG) 2007 Five Percent Plan for PM10 for 

the Maricopa County Nonattainment Area 

As a result of the failure to attain the standard, MAG began developing a Five Percent Plan for 

Maricopa County as required under the Clean Air Act Section 189(d). The Five Percent Plan 

requires the reduction of PM10 emissions by at least five percent per year until the standard is 

attained, and no violations occur at previously violating PM10 monitors. To develop the plan, 

MAG conducted a study to determine the sources of PM10 emissions contributing to violations of 

the PM10 standard at monitors in the nonattainment area during stagnant conditions and to 

characterize the deposition of PM10 particles emitted by these sources. The study identified a 

number of sources of PM10 emissions including: trackout, dragout from unpaved or poorly 

maintained paved roads or parking lots, unpaved shoulders, unpaved roads, open burning, 

agriculture, and vehicle activity on unpaved parking areas and vacant lots. Preliminary results 

from the study were used to evaluate control measures and the final results were used in the 

modeling demonstration. 

The Maricopa County Air Quality Department conducted a periodic PM10 emission inventory for 

the Maricopa County Nonattainment Area in 2005. The inventory showed that agriculture 

 

1 Plan for Attainment of the 24-hour PM–10 Standard—Maricopa County PM–10 Nonattainment Area, Arizona 

Department of Environmental Quality (ADEQ), May, 1997, submitted May 9, 1997, approved in part and 

disapproved in part on August 3, 1997 (62 FR 41856). Maricopa County PM–10 Serious Area State Implementation 

Plan Revision, Agricultural Best Management Practices (BMP), ADEQ, June 2000, submitted on June 13, 2001. 2 Serious Area Committed Particulate Control Measures for PM–10 for the Maricopa County Nonattainment Area 

and Support Technical Analysis, MAG, December 1997, submitted December 11, 1997. Revised Maricopa 

Association of Governments 1999 Serious Area Particulate Plan for PM–10 for the Maricopa County 

Nonattainment Area, February 2000, submitted February 16, 2000. On January 8, 2002, Arizona submitted 

revisions to the Maricopa County’s commitments to improve its fugitive dust rule which were in this plan. 

3

 These include the revised Maricopa County Environmental Services Department (MCESD) Rule 310, Fugitive 

Dust Sources (adopted February 16, 2000) and Rule 310.01, Fugitive Dust from Open Areas, Vacant Lots, Unpaved 

Parking Lots, and Unpaved Roadways (adopted February 16, 2000), both submitted on March 2, 2000; the revised 

Maricopa County Residential Woodburning Restrictions Ordinance (adopted November 17, 1999) submitted on 

January 28, 2000; and the Agricultural BMP General Permit Rule submitted on July 11, 2000, approved October 11 

2001 (66 FR 51869). 

11
contributes approximately three percent to total annual PM10 emissions in the nonattainment area 

(Figure 2). This regional and annual emission profile does not provide any context for localized 

emissions that can contribute to 24-hour average PM10 NAAQS exceedances. Agricultural dust 

represents a greater proportion of the PM10 emissions that contributed to 24-hour average 

exceedances at two sites in the nonattainment area. 

Figure 2: Annual 2005 PM10 Emissions in the PM10 Nonattainment Area 

stationary source point sources

industrial processes 2%

fuel combustion & fires

10% 4%

7% agriculture

construction (residential)

3% construction (commercial)

construction (road) 16%

other land clearing

14% travel on unpaved parking lots

offroad recreational vehicles

Source: 2005 Periodic Emission Inventory for the Maricopa County, Arizona Nonattainment Area. Maricopa County Air 

Quality Department, May 2007.

In order to reduce PM10 emissions for the contribution from agriculture, the Committee added 

BMPs to those already contained in the 2001 Agricultural Best Management Practices SIP. The 

Committee also adopted an additional requirement for two BMPs per agricultural category (for 

details regarding the new BMPs and additional requirements see Chapter 2.0). Concurrently, the 

Arizona State Legislature passed Senate Bill (SB) 1552 (Laws 2007) to address the failure to 

attain the PM10 standard and other air quality issues. SB 1552 contained changes and additions 

to A.R.S. §49-457 – Agricultural Best Management Practices Committee, Members, Powers, 

Permits, Definitions. The Committee then revised Arizona Administrative Code (A.A.C.) R18-2-

610 – Definitions for R18-2-611; and R18-2-611 – Agricultural PM10 General Permit, Maricopa 

PM10 Nonattainment Area and Maricopa County Portion of Area A (for rule revision details see 

Section 2.2). 

13%

3% 9% 5%

3%

7%

1%

2%

2% leaf blowers fugitive dust

windblown vacant

windblown other

nonroad equipment

exhaust/tire wear/brake wear 1%

paved roads (including trackout)

unpaved roads

12
1.4 Agricultural Best Management Practices SIP Revision 

This document contains revisions to the Maricopa County PM10 Serious Area State 

Implementation Plan – Agricultural Best Management Practices, originally submitted in 2001. 

These revisions include: 

 Senate Bill 1552 requirement, 

 New BMPs selected by the Committee, 

 Description of BMP outreach, and 

 Revisions to the BMP guidance booklet. 

13
CHAPTER 2.0 AGRICULTURAL BEST MANAGEMENT PRACTICES SELECTION 

PROCESS 

2.1 Actions of the Governor’s Agricultural Best Management Practices Committee 

The Committee met in 2006 as a proactive step to research alternatives to further reduce PM10 

emissions from agricultural activities. The Committee reconvened the Agricultural BMP 

Technical Workgroup to review and analyze similar agricultural management programs in 

California, the existing program in Maricopa County, and management practices proposed by the 

Maricopa Association of Governments (MAG). 

The Workgroup invited representatives from San Joaquin Valley and Imperial Valley, California 

to present and discuss the Conservation Management Practices (CMP) Programs in their 

respective counties. Representatives from MAG were also invited to several Committee 

meetings to present and discuss alternative practices for use as BMPs. MAG’s suggestions 

included calculating the emissions impacts from the elimination of plow-downs after the pink 

boll worm is eradicated, staggering plow-downs, cessation of tilling on high wind days, 

calculating the emissions impacts from the reduction of agricultural land once it converts to 

development, and the implementation of BMPs to Area A, a planning area larger than the 

nonattainment area. 

The Workgroup forwarded six new BMPs to the Committee for evaluation. These BMPs 

included: integrated pest management (IPM), precision farming, green chop, transgenic crops, 

transplanting, and minimized vehicle use to ten vehicle trips per day. In addition to reviewing 

these practices for feasibility, the Committee requested that ADEQ staff conduct a comparison 

analysis of BMPs to determine potential emission reductions. The Committee also requested that 

the Workgroup review additional analysis from ADEQ regarding PM10 emissions during stagnant 

air conditions prior to further discussion or action on BMPs related to cessation of tilling (for 

more information on both the comparison analysis and analysis of PM10 emissions see Appendix 

B). 

After reviewing the comparison analysis of the estimated emissions reductions for the six 

additional BMPs, the Committee selected practices that were feasible and applicable for farmers 

in Maricopa County. Four BMPs were initially adopted: IPM, precision farming, green chop, 

and transgenic crops (for descriptions of the BMPs adopted by the Committee see Chapter 3.0). 

The analysis of the PM10 data showed that on stagnant air days, PM10 concentrations start to rise 

after sundown, are relatively constant until about 4:00 a.m., and reach a maximum peak around 

8:00 a.m. ADEQ staff proposed several options for a time frame to cease or reduce tilling: 

reduce tilling on weekdays (tilling would occur on weekends), limit tilling on any day between 

6:00 p.m. and 9:00 a.m., or limit tilling on any day between 6:00 p.m. and 7:00 a.m. In order to 

maintain economic feasibility of the BMP and contribute to reductions of PM10 concentrations, 

the Committee agreed that establishing a time frame of 2:00 a.m. to 8:00 a.m. for the cessation of 

night tilling operations on stagnant air days was appropriate. The Committee adopted the 

cessation of night tilling from 2:00 a.m. to 8:00 a.m. during stagnant air conditions on high 

pollution advisory (HPA) days as a fifth additional BMP. 

14
15

 

2.2 Senate Bill 1552 and Committee Actions 

While the Technical Workgroup was conducting its review and analysis of BMPs, the Arizona 

Legislature revised Arizona Revised Statutes (A.R.S.) §49-457 in Section 14 of SB 1552. The 

Committee discussed extending the application of BMPs to the Maricopa County portion of Area 

A, as originally suggested by MAG (See Figure 2) and further discussed the consideration of 

requiring two BMPs per category versus one BMP per category as originally required. 

Requiring two BMPs per category (the three categories being tillage and harvest, non-cropland, 

and cropland) actually served to increase flexibility. Expanding the use of BMPs into the 

Maricopa County Portion of Area A captured monitors with data showing exceedances possibly 

due in part to agricultural activities located on the edges of the nonattainment area but within the 

Maricopa County portion of Area A. 

As signed by the Governor, SB 1552 amended the statute to require two BMPs to be 

implemented per agricultural management category beginning December 31, 2007, and revised 

the definition of the regulated area for BMPs to include the Maricopa County portion of Area A 

(as defined in A.R.S §49-541). These changes, in addition to the newly adopted BMPs, required 

revisions to R18-2-610 – Definitions for R18-2-611; and R18-2-611 – Agricultural PM10 General 

Permit, Maricopa PM10 Nonattainment Area and Maricopa County Portion of Area A. The rule 

was developed as an exempt rule4 to facilitate inclusion in the MAG 2007 Five Percent Plan for 

PM-10 for the Maricopa County Nonattainment Area, submitted by ADEQ to EPA on December 

21, 2007. The now codified version of R18-2-610 and 611 as it appears in the A.A.C. is 

submitted in this SIP Revision and can be found in Appendix A. 

4

 An exempt rulemaking in Arizona is not submitted to the Governor’s Regulatory Review Council but rather 

submitted directly to the Secretary of State for inclusion in the Code through legislative enactment. Public 

comments on the exempt rule were made available as part of the public process for the Five Percent Plan. 
Figure 3: Map of PM10 Nonattainment Area and Area A 
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CHAPTER 3.0 ADDITIONAL AGRICULTURAL BEST MANAGEMENT PRACTICES 

This chapter contains descriptions and percent emission reduction of the five BMPs that were 

selected by the Governor’s Agricultural Best Management Practices Committee. 

3.1 Best Management Practices 

3.1.1 Cessation of Night Tillage on High Pollution Advisory Days 

Cessation of night tilling during high pollution advisory days is the stopping of agricultural 

tillings during the early morning hours to limit the concentration of PM10 emissions while still 

allowing for other farming activities to occur. Notification of high pollution advisory days for 

PM10 [http://www.azdeq.gov/ensemble.pdf] is assisted by test messaging services provided by 

ADEQ [http://www.azdeq.gov/sms.html]. 

The Committee selected this BMP based on its practicality, feasibility, and efficiency regarding 

agricultural activities in Maricopa County. Based on an analysis conducted by ADEQ, the 

emission reduction is two percent for the Cessation of Night Tillage on High Pollution Advisory 

Days BMP. 

3.1.2 Green Chop 

Green chopping is a harvesting practice commonly used with forage crops. The crop is cut and 

simultaneously harvested, without allowing it to dry in the field, thus reducing multiple 

equipment passes. Fewer equipment passes reduce disturbance of the soil thus reducing the 

amount of PM10 emitted. 

The Committee selected this BMP based on its practicality, feasibility, and efficiency regarding 

agricultural activities in Maricopa County. Based on a comparison analysis of BMPs conducted 

by ADEQ, the emission reduction is between 10 and 20 percent for the Green Chop BMP. 

3.1.3 Integrated Pest Management 

Integrated pest management (IPM) is an agricultural-management practice that uses a 

combination of techniques including organic, conventional and biological farming practices to 

suppress pests. Implementation of IPM commonly uses a four-tiered approach: set action 

thresholds for an identified pest, monitor and identify pests, prevent pests from becoming a 

threat, and control the pest. The fourth step may require evaluation of the previous steps to 

determine if the implementation process is working or if additional control methods are required. 

Implementation of IPM results in fewer pests and thus reduces the need and/or number of passes 

for spraying pesticides and also the need for additional tillage. 

18
The Committee selected this BMP based on its practicality, feasibility, and efficiency regarding

agricultural activities in Maricopa County. Based on a comparison analysis of BMPs conducted 

by ADEQ, the emission reduction is between 12 and 19 percent for the IPM BMP. 

3.1.4 Precision Farming 

Precision farming is an agricultural practice that uses global position systems (GPS), sensors, 

satellite or aerial images, remote sensing, and geographical information systems (GIS). The use 

of this technology allows farmers to account for variable field conditions such as soil type, 

landscape characteristics, types of pests, and crop information. This information is used to 

precisely evaluate optimum sowing density, estimate fertilizer applications, and calculate the 

position of agricultural equipment in the field. A primary objective for using this practice is to 

determine the exact location of agricultural equipment as it operates in a field so that a farmer 

can treat specific areas and reduce overlap. Reduced overlap results in fewer equipment passes 

and reduces the amount of PM10 emitted from disturbing the soil. This practice also allows a 

farmer to operate during inclement weather and at night since the farmer can accurately 

determine their exact location in the field. 

The Committee selected this BMP based on its practicality, feasibility, and efficiency regarding 

agricultural activities in Maricopa County. Based on a comparison analysis of BMPs conducted 

by ADEQ, the emission reduction is 15 percent for the Precision Farming BMP. 

3.1.5 Transgenic Crops 

Transgenic crops are genetically modified organisms (GMOs), which are genetically engineered 

crops. This form of engineering alters the genetic material of the organism by inserting or 

transferring genes from other species to cause the expression of modified traits. There are many 

reasons for using transgenic crops such as pest resistance or increased yield. In Arizona, one 

example of the use of a transgenic crop is BT cotton. BT cotton is genetically modified to 

produce a toxin that kills caterpillars, particularly the pink bollworm. The use of transgenic 

crops can reduce the need for tillage, fertilizing, pesticide application, or other cultivation 

activities and, thus, reduces soil disturbance and PM10 emissions. 

The Committee selected this BMP based on its practicality, feasibility, and efficiency regarding 

agricultural activities in Maricopa County. Based on a comparison analysis of BMPs conducted 

by ADEQ, the emission reduction is between two and 12 percent for the Transgenic Crops BMP. 

3.2 Emissions Reductions from Revisions to the BMP Program 

This section discusses the emissions reductions resulting from the revision to the BMP Program. 

These are the reductions that may result from the additional BMPs, using two BMPs per 

agricultural category, and the expansion of the area of application of the BMP Program. 

Additional information on the emission reductions resulting from “Cessation of Night Tilling” 

19
BMP as a second BMP in the Tilling & Harvest category and extending the Agricultural BMP 

program to the Maricopa County Portion of Area A outside of the Maricopa County PM10

Nonattainment Area is also discussed. 

3.2.1 Number of BMPs Required per Agricultural Category 

The original BMP Program required growers to choose one BMP per agricultural land/use 

category: Tillage and Harvest, Non-Cropland, and Cropland. The revisions to A.R.S §49-541, 

and A.A.C. R18-2-610 and 611 increased the number of BMPs required per category from one to 

two BMPs. With the revised program, growers are required to select one additional BMP for 

each of the BMP categories (total of six BMPs). Using a second BMP per category provides 

greater emissions reductions than the use of a single BMP. 

3.2.2 Cessation of Night Tilling 

As outlined in Section 3.1.1, “Cessation of Night Tilling” in the Tillage and Harvest category, 

has a relatively low annual emissions reduction of only two percent; however, its actual 

reduction of ambient PM10 concentrations is much higher. This is because the PM10 emissions 

from night tilling occur during the most critical time of a stagnation period, 2:00 a.m. and 8:00 

a.m., when lack of vertical and horizontal mixing can allow PM10 concentrations to steadily 

increase. 

The estimated 15 tons per year of PM10 emission reductions from this BMP was projected to 

occur on the nine stagnation days (annual average) that coincide on days when agricultural tilling 

is done in Maricopa County. Thus, the two percent annual total emissions reduction value can be 

misleading since the actual emission reductions cover only nine days as opposed to 365 days. 

The “Cessation of Night Tilling” BMP does not replace one of the original BMPs that is required 

for the Tillage & Harvest category. This BMP is in addition to the first BMP that is required for 

the Tillage & Harvest category. Thus, if this BMP is selected by a grower, it strengthens the 

Maricopa County PM10 Serious Area SIP, since it provides PM10 emission reductions in addition 

to the first BMP’s emission reductions. 

3.2.3 Extension of the Agricultural BMP Program to the Maricopa County Portion of Area A 

As a result of extending the area of application of the BMP Program outside of the PM10

nonattainment area, it was estimated that an additional 26,004 acres of agricultural land would 

become subject to the Agricultural BMP Program. This is an almost 30 percent increase in 

agricultural land subject to the BMP Program. The projected emissions reductions from the 

extension take into account application of two "additional" Agricultural BMPs, instead of just 

one additional Agricultural BMP. 

20
3.3 Conclusion 

The revisions to the BMP Program include: five additional BMPs, two BMPs required per 

agricultural category, and extension of the area of application of the BMP Program. All of the 

practices in the BMP Program are recognized as BACM and MSM and provide a reduction in 

PM10 emissions from agricultural activities. These revisions to the overall AgBMP Program are 

cumulative, and the overall impact leads to strengthening the AgBMP SIP. 

21
CHAPTER 4.0 OUTREACH

4.1 Public Outreach Activities 

After finalizing revisions to R18-2-610 – Definitions for R18-2-611; and R18-2-611 – 

Agricultural PM10 General Permit, Maricopa PM10 Nonattainment Area and Maricopa County 

Portion of Area A, the Committee discussed revisions to the Guide to Agricultural PM10 Best 

Management Practices as well as outreach strategies to inform the agricultural community of the 

changes to the BMP Program. The Committee approved revisions to the Guide to include the 

five new BMPs, changes to the number of BMPs required for each category and the expansion of 

the application area for BMPs. The Committee also approved a pocket guide to be distributed 

along with the booklet; the pocket guide replaced the previous pamphlet version of the larger 

Guide. The Pocket Guide to Agricultural PM10 Best Management Practices provides a brief 

overview of the BMPs that can be utilized in each agricultural category, and contains contact 

information for additional information regarding the BMP Program. 

Once the publications were available, outreach meetings were coordinated by the Arizona 

Department of Agriculture (ADA) and the Arizona Farm Bureau. Two separate meetings were 

held during May 2008 (Estrella Mountain Community College and the Arizona Farm Bureau 

Office located in Gilbert). Continued outreach is maintained by the Agricultural Consultation 

and Testing (ACT) Program at the ADA. Representatives from the ADA also conduct on-site 

visits to the agricultural community in order to provide compliance assistance and training 

regarding implementation of the BMP program. The ADA maintains a Web site for the ACT 

Program, http://www.azda.gov/ACT/act.htm, to provide information to the public regarding their 

services. ADEQ also participates in outreach for the BMP Program. If complaints are reported, 

a representative from ADEQ will meet with the farmer, review their chosen BMPs, and discuss 

options to reduce PM10 emissions from the agricultural activities. 

22
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23
24

CHAPTER 5.0 CONCLUSION 

The purpose of the Agricultural BMP Program is to provide farmers with alternative practices 

that will help reduce PM10 emissions and lower concentrations of PM10 in the Maricopa County 

Nonattainment Area. The original Program implemented in 2001 allowed farmers to pick BMPs 

that were both economically feasible and practicable. The additional BMPs will give farmers 

more Program flexibility and extend the BMP application area to include more farmland in the 

BMP Program and capture farmland on the periphery of the PM10 nonattainment area boundary. 

The revisions to the Agricultural BMP Program strengthen the existing Agricultural BMP SIP. 

Therefore, with this submittal, ADEQ requests that EPA approve this SIP Revision to the 2001 

Agricultural Best Management Practices, Maricopa County PM10 Serious Area State 

Implementation Plan. 
APPENDIX A 

Agricultural Best Management Practices Rule 
Supp. 08-3 Page 68 September 30, 2008

Title 18, Ch. 2 Arizona Administrative Code

Department of Environmental Quality – Air Pollution Control

excessive amounts of particulate matter from becoming airborne.

Reasonable precautions shall mean wetting, chemical stabilization,

revegetation or such other measures as are approved by the Director.

Historical ote

Section R18-2-608 renumbered from R18-2-408, new 

Section R18-2-408 adopted effective November 15, 1993 

(Supp. 93-4).

R18-2-609. Agricultural Practices

A person shall not cause, suffer, allow, or permit the performance of

agricultural practices outside the Phoenix and Yuma planning areas,

as defined in 40 CFR 81.303, which is incorporated by reference in

R18-2-210, including tilling of land and application of fertilizers

without taking reasonable precautions to prevent excessive amounts

of particulate matter from becoming airborne.

Historical ote

Section R18-2-609 renumbered from R18-2-409 effective 

November 15, 1993 (Supp. 93-4). Amended by final rulemaking at 6 A.A.R. 2009, effective May 12, 2000 (Supp. 

00-2). Amended by final rulemaking at 11 A.A.R. 2210, 

effective July 18, 2005 (Supp. 05-2).

R18-2-610. Definitions for R18-2-611

The definitions in Article 1 of this Chapter and the following definitions apply to R18-2-611:

1. “Access restriction” means restricting or eliminating public access to noncropland with signs or physical obstruction.

2. “Aggregate cover” means gravel, concrete, recycled road

base, caliche, or other similar material applied to noncropland.

3. “Area A” means the area delineated according to A.R.S.

§ 49-541(1).

4. “Artificial wind barrier” means a physical barrier to the

wind.

5. “Best management practice” means a technique verified

by scientific research, that on a case-by-case basis is

practical, economically feasible, and effective in reducing

PM10 emissions from a regulated agricultural activity.

6. “Chemical irrigation” means applying a fertilizer, pesticide, or other agricultural chemical to cropland through

an irrigation system.

7. “Cessation of Night Tilling” means the discontinuation of

night tilling on high pollution advisory days during stagnant air conditions.

8. “Combining tractor operations” means performing two or

more tillage, cultivation, planting, or harvesting operations with a single tractor or harvester pass.

9. “Commercial farm” means 10 or more contiguous acres

of land used for agricultural purposes within the boundary of the Maricopa PM10 nonattainment area and Maricopa County portion of Area A.

10. “Commercial farmer” means an individual, entity, or joint

operation in general control of a commercial farm.

11. “Committee” means the Governor’s Agricultural Best

Management Practices Committee.

12. “Cover crop” means plants or a green manure crop grown

for seasonal soil protection or soil improvement.

13. “Critical area planting” means using trees, shrubs, vines,

grasses, or other vegetative cover on noncropland.

14. “Cropland” means land on a commercial farm that:

a. Is within the time-frame of final harvest to plant

emergence;

b. Has been tilled in a prior year and is suitable for crop

production, but is currently fallow; or

c. Is a turn-row.

15. “Cross-wind ridges” means soil ridges formed by a tillage

operation.

16. “Cross-wind strip-cropping” means planting strips of

alternating crops within the same field.

17. “Cross-wind vegetative strips” means herbaceous cover

established in one or more strips within the same field.

18. “Equipment modification” means modifying agricultural

equipment to prevent or reduce particulate matter generation from cropland.

19. “Forage Crop” means a product grown for consumption

by any domestic animal.

20. “Genetically Modified” means a living organism whose

genetic material has been altered, changing one or more

of its characteristics.

21. “GMO: Genetically Modified Organism” means a plant

that has been altered by a genetic exchange with another

organism.

22. “GPS: Global Position Satellite System” means using a

satellite navigation system on farm equipment to calculate position in the field.

23. “Green Chop” means the harvesting of a forage crop

without allowing it to dry in the field.

24. “High Pollution Advisory” means a public notification

issued by the Department when the ambient concentrations of PM10 may exceed the federal health standard.

25. “Integrated Pest Management” means the use of a combination of techniques including organic, conventional, and

biological farming practices.

26. “Limited activity during a high-wind event” means performing no tillage or soil preparation activity when the

measured wind speed at 6 feet in height is more than 25

mph at the commercial farm site.

27. “Manure application” means applying animal waste or

biosolids to a soil surface.

28. “Maricopa PM10 nonattainment area” means the Phoenix

planning area as defined in 40 CFR 81.303, which is

incorporated by reference in R18-2-210.

29. “Mulching” means applying plant residue or other material that is not produced onsite to a soil surface.

30. “Multi-year crop” means a crop, pasture, or orchard that

is grown, or will be grown, on a continuous basis for

more than one year.

31. “Noncropland” means any commercial farm land that:

a. Is no longer used for agricultural production;

b. Is no longer suitable for production of crops;

c. Is subject to a restrictive easement or contract that

prohibits use for the production of crops; or

d. Includes a private farm road, ditch, ditch bank,

equipment yard, storage yard, or well head.

32. “Night Tilling” means preparing the land for the raising

of crops between the hours of 2:00 a.m. and 8:00 a.m.

33. “Organic Farming Practices” means using biological or

non-chemical agricultural methods.
Arizona Administrative Code Title 18, Ch. 2

Department of Environmental Quality – Air Pollution Control

September 30, 2008 Page 69 Supp. 08-3

34. “Permanent cover” means a perennial vegetative cover on

cropland.

35. “Planting based on soil moisture” means applying water

to soil before performing planting operations.

36. “Precision Farming” means using GPS to precisely guide

farm equipment in the field.

37. “Reduce vehicle speed” means operating farm vehicles or

farm equipment on unpaved private farm roads at speeds

not to exceed 20 mph.

38. “Reduced harvest activity” means reducing the number of

harvest passes using a mechanized method to cut and

remove crops from a field.

39. “Reduced tillage system” means reducing the number of

tillage operations used to produce a crop.

40. “Regulated agricultural activity” means a commercial

farming practice that may produce PM10 within the Maricopa PM10 nonattainment area and Maricopa County portion of Area A.

41. “Residue management” means managing the amount and

distribution of crop and other plant residues on a soil surface.

42. “Sequential cropping” means growing crops in a

sequence that minimizes the amount of time bare soil is

exposed on a field.

43. “Surface roughening” means manipulating a soil surface

to produce or maintain clods.

44. “Stagnant Air Conditions” means a meteorological

regime where warm air aloft overlies cooler air near the

surface and little if any vertical mixing occurs.

45. “Synthetic particulate suppressant” means a manufactured product such as lignosulfate, calcium chloride,

magnesium chloride, an emulsion of a petroleum product,

an enzyme product, and polyacrylamide that is used to

control particulate matter.

46. “Tillage and harvest” means any mechanical practice that

physically disturbs cropland or crops on a commercial

farm.

47. “Tillage based on soil moisture” means applying water to

soil before or during tillage, or delaying tillage to coincide with precipitation.

48. “Timing of a tillage operation” means performing tillage

operations at a time that will minimize the soil’s susceptibility to generate PM10.

49. “Track-out control system” means a device to remove

mud or soil from a vehicle before the vehicle enters a

paved public road.

50. “Transgenic Crops” means the use of plants that are

genetically modified.

51. “Tree, shrub, or windbreak planting” means providing a

woody vegetative barrier to the wind.

52. “Watering” means applying water to noncropland.

Historical ote

Former Section R18-2-610 renumbered to R18-2-612; 

new Section R18-2-610 adopted by final rulemaking at 6 

A.A.R. 2009, effective May 12, 2000 (Supp. 00-2). 

Amended by exempt rulemaking at 13 A.A.R. 4326, 

effective November 14, 2007 (Supp. 07-4).

R18-2-611. Agricultural PM10 General Permit; Maricopa

PM10 onattainment Area and Maricopa County Portion of

Area A

A. A commercial farmer shall comply with this Section by

December 31, 2007.

B. A commercial farmer, who begins a regulated agricultural

activity after December 31, 2000, shall comply with this Section within 18 months of beginning the regulated agricultural

activity.

C. A commercial farmer shall implement at least two best management practices from each of the following categories:

1. Tillage and harvest, subsection (E);

2. Noncropland, subsection (F); and

3. Cropland, subsection (G). A commercial farmer may

implement more than one best management practice for

one or more of the categories.

D. A commercial farmer shall ensure that the implementation of

all selected best management practices does not violate any

other local, state, or federal law.

E. A commercial farmer shall implement at least two of the following best management practices to reduce PM10 emissions

during tillage and harvest activities:

1. Chemical irrigation,

2. Combining tractor operations,

3. Equipment modification,

4. Green Chop,

5. Integrated Pest Management,

6. Limited activity during a high-wind event,

7. Multi-year crop,

8. Cessation of Night Tilling,

9. Planting based on soil moisture,

10. Precision Farming,

11. Reduced harvest activity,

12. Reduced tillage system,

13. Tillage based on soil moisture, 

14. Timing of a tillage operation, or

15. Transgenic Crops.

F. A commercial farmer shall implement at least two of the following best management practices to reduce PM10 emissions

from noncropland:

1. Access restriction;

2. Aggregate cover;

3. Artificial wind barrier;

4. Critical area planting;

5. Manure application;

6. Reduce vehicle speed;

7. Synthetic particulate suppressant;

8. Track-out control system;

9. Tree, shrub, or windbreak planting; or

10. Watering.

G. A commercial farmer shall implement at least two of the following best management practices to reduce PM10 emissions

from cropland:

1. Artificial wind barrier;

2. Cover crop;

3. Cross-wind ridges;

4. Cross-wind strip-cropping;

5. Cross-wind vegetative strips;

6. Integrated Pest Management;

7. Manure application;

8. Mulching;

9. Multi-year crop;

10. Permanent cover;

11. Planting based on soil moisture;

12. Precision Farming;

13. Residue management;
Supp. 08-3 Page 70 September 30, 2008

Title 18, Ch. 2 Arizona Administrative Code

Department of Environmental Quality – Air Pollution Control

14. Sequential cropping;

15. Surface roughening; or

16. Tree, shrub, or windbreak planting.

H. A person may develop different practices not contained in subsections (E), (F), or (G) that reduce PM10. A person may submit practices that are proven effective through on-farm

demonstration trials to the Committee. The Committee may

meet to review the submitted practices.

I. A commercial farmer shall maintain a record demonstrating

compliance with this Section. The record shall be provided to

the Director within two business days of notice to the commercial farmer. The record shall contain:

1. The name of the commercial farmer,

2. The mailing address or physical address of the commercial farm, and

3. The best management practices selected for tillage and

harvest, noncropland, and cropland.

J. The Director shall not assess a fee to a commercial farmer for

coverage under the agricultural PM10 general permit.

K. The Director shall document noncompliance with this Section

before issuing a compliance order.

L. A commercial farmer who is not in compliance with this Section is subject to the provisions in A.R.S. § 49-457 (I), (J), and

(K).

Historical ote

New Section adopted by final rulemaking at 6 A.A.R.

2009, effective May 12, 2000 (Supp. 00-2). Amended by 

exempt rulemaking at 13 A.A.R. 4326, effective November 14, 2007 (Supp. 07-4).

R18-2-612. Definitions for R18-2-613

1. “Access restriction” means restricting or eliminating public access to noncropland with signs or physical obstruction.

2. “Aggregate cover” means gravel, concrete, recycled road

base, caliche, or other similar material applied to noncropland.

3. “Artificial wind barrier” means a physical barrier to the

wind.

4. “Bed row spacing” means increasing or decreasing the

size of a planting bed area to reduce the number of passes

and soil disturbance by increasing plant density.

5. “Best management practice” means a technique verified

by scientific research, that on a case-by-case basis is

practical, economically feasible, and effective in reducing

PM10 emissions from a regulated agricultural activity.

6. “Chemical irrigation” means applying a fertilizer, pesticide, or other agricultural chemical to cropland through

an irrigation system.

7. “Combining tractor operations” means performing two or

more tillage, cultivation, planting, or harvesting operations with a single tractor or harvester pass.

8. “Commercial farm” means 10 or more contiguous acres

of land used for agricultural purposes within the boundary of the Yuma PM10 nonattainment area.

9. “Commercial farmer” means an individual, entity, or joint

operation in general control of a commercial farm.

10. “Conservation irrigation” means the use of drips, sprinklers, or underground lines to conserve water, and to

reduce the weed population, the need for tillage, and soil

compaction.

11. “Conservation tillage” means types of tillage that reduce

the number of passes and the amount of soil disturbance.

12. “Cover crop” means plants or a green manure crop grown

for seasonal soil protection or soil improvement.

13. “Critical area planting” means using trees, shrubs, vines,

grasses, or other vegetative cover on noncropland.

14. “Cropland” means land on a commercial farm that:

a. Is within the time-frame of final harvest to plant

emergence;

b. Has been tilled in a prior year and is suitable for crop

production, but is currently fallow; or

c. Is a turn-row.

15. “Cross-wind ridges” means soil ridges formed by a tillage

operation.

16. “Cross-wind strip-cropping” means planting strips of

alternating crops within the same field.

17. “Cross-wind vegetative strips” means herbaceous cover

established in one or more strips within the same field.

18. “Equipment modification” means modifying agricultural

equipment to prevent or reduce particulate matter generation from cropland.

19. “Limited activity during a high-wind event” means performing no tillage or soil preparation activity when the

measured wind speed at six feet in height is more than 25

mph at the commercial farm site.

20. “Manure application” means applying animal waste or

biosolids to a soil surface.

21. “Mulching” means applying plant residue or other material that is not produced onsite to a soil surface.

22. “Multi-year crop” means a crop, pasture, or orchard that

is grown, or will be grown, on a continuous basis for

more than one year.

23. “Night farming” means performing regulated agricultural

activities at night when moisture levels are higher and

winds are lighter.

24. “Noncropland” means any commercial farmland that:

a. Is no longer used for agricultural production;

b. Is no longer suitable for production of crops;

c. Is subject to a restrictive easement or contract that

prohibits use for the production of crops; or

d. Includes a private farm road, ditch, ditch bank,

equipment yard, storage yard, or well head.

25. “Permanent cover” means a perennial vegetative cover on

cropland.

26. “Planting based on soil moisture” means applying water

to soil before performing planting operations.

27. “Precision farming” means use of satellite navigation to

calculate position in the field, to reduce overlap during

field operations, and allow operations to occur during

nighttime and inclement weather, thus generating less

PM10.

28. “Reduce vehicle speed” means operating farm vehicles or

farm equipment on unpaved farm roads at speeds not to

exceed 20 mph.

29. “Reduced harvest activity” means reducing the number of

harvest passes using a mechanized method to cut and

remove crops from a field.

30. “Regulated agricultural activity” means a commercial

farming practice that may produce PM10 within the Yuma

PM10 nonattainment area.

31. “Residue management” means managing the amount and

distribution of crop and other plant residues on a soil surface.

32. “Sequential cropping” means growing crops in a

sequence that minimizes the amount of time bare soil is

exposed on a field.

33. “Surface roughening” means manipulating a soil surface

to produce or maintain clods.

34. “Synthetic particulate suppressant” means a manufactured product such as lignosulfate, calcium chloride,
APPENDIX B 

Technical Support Document 
i 

AGRICULTURAL BEST MANAGEMENT PRACTICES 

TECHNICAL SUPPORT DOCUMENT 

Arizona Department of Environmental Quality 

January 11, 2010 
ii 

TABLE OF CONTENTS

1.1 INTRODUCTION.............................................................................................................................................1 

1.2 COMPARISON OF MARICOPA COUNTY BMPs AND SAN JOAQUIN CMPs..........................................1 

1.2.1 Methodology..............................................................................................................................................1 

1. Estimation of Crop Acres in Maricopa County PM10 Nonattainment Area ........................................... 1 

2. Calculation of Uncontrolled PM10 Emissions in Maricopa County PM10 Nonattainment Area............. 2 

3. Calculation of PM10 Emissions Reduction by Crop and Control Measure........................................ 3

1.2.2 Summary of Emissions Reductions ...........................................................................................................4 

1.3 AGRICULTURAL BMPS IN SENATE BILL 1552 .......................................................................................10 

1.3.1 Effect of One Additional Agricultural BMP in Maricopa County PM-10 Nonattainment Area..............10 

1. Percent Emission Reduction by Agricultural BMP Category.............................................................. 10 

2. Projected Crop Acreage in Maricopa County ...................................................................................... 12 

3. Rate of Change Factors........................................................................................................................ 13 

4. Projected Agricultural Emissions in Maricopa County PM10 Nonattainment Area............................. 14 

5. Projected Emission Reductions in Maricopa County PM10 Nonattainment Area................................ 14

1.3.2 Extending Agricultural BMP Program to Maricopa County Portion of Area A ......................................16

1. Percent Agricultural Land In Maricopa County .................................................................................. 16 

2 Land in MC Portion of Area A............................................................................................................. 16 

3. Agricultural Land in MC Portion of Area A ........................................................................................ 16 

4. Agricultural Land in Maricopa County PM10 Nonattainment Area..................................................... 17 

5. Ratio of Agricultural Land in MC Portion of Area A to Agricultural Land in NAA ........................... 17 

6. Projected Emission Reduction in MC Portion of Area A .................................................................... 17 

7. Emission Reductions Due to Revised Agricultural BMP Program in Senate Bill 1552 ...................... 19

1.3.3 Cessation of Night Tillage on High Pollution Advisory Days.................................................................20 

1. Comparison of Occurrence of Stagnation Days with Tillage Days for Maricopa County................... 20 

2. Uncontrolled Tillage Emissions in NAA for Year 2005 ...................................................................... 21 

3. Controlled Tillage Emissions in NAA for Year 2005 .......................................................................... 21 

4. Uncontrolled and Controlled Tillage Emissions in NAA for Years 2008 - 2010................................. 22 

5. Uncontrolled and Controlled Tillage Emissions in MC Portion of Area A for Years 2008 - 2010...... 23 

6. Uncontrolled and Controlled Tillage Emissions in Area A for Years 2008 - 2010 .............................. 23 

7. Controlled Tillage Emissions in Area A by Crop for Years 2008 - 2010 ............................................. 24 

8. Emission Reductions from Banning Tilling on HPAs in Area A ......................................................... 25 

9. Emission Reductions from Banning Tilling from 2 AM to 8 AM on HPAs in Area A........................ 26 

10. Percent Emission Reduction from Banning Tilling from 2 AM to 8 AM on HPAs in Area A ........... 26

1.3.4 Summary of Emissions Reductions from Senate Bill 1552.....................................................................27 

1.4 REFERENCES................................................................................................................................................28 

ATTACHMENT #1 .............................................................................................................................Attachment-1 
iii 

LIST OF TABLES 

Table 1 Emission Factors and Adjustment Factors ......................................................................................... 4 

Table 2 Ranking of Emission Reductions From Maricopa County BMPs and San Joaquin CMPs ............... 5 

Table 3 Calculation of Percent Emission Reductions by Ag BMP Group.................................................... 11 

Table 4 Historical and Projected Crop Acreage in Maricopa County........................................................... 13 

Table 5 Rate of Change Factors for Agricultural Land in Maricopa County................................................ 13 

Table 6 PM10 Emissions for Maricopa County PM10 Nonattainment Area................................................... 14 

Table 7 Emission Reductions for Maricopa County PM10 Nonattainment Area........................................... 15 

Table 8 Emission Reductions for MC Portion of Area A.............................................................................. 18 

Table 9 Emission Reductions from Agricultural BMP Program in Senate Bill 1552 ................................... 20 

Table10 Year 2005 Stagnation Days and Potential Tillage Days in Maricopa County ................................. 20 

Table 11 Uncontrolled Tillage Emissions in NAA - Year 2005 ..................................................................... 21 

Table 12 Controlled Tillage Emissions in NAA - Year 2005 ......................................................................... 22 

Table 13 Projected Uncontrolled and Controlled Tillage Emissions (2 BMPs) in NAA ............................... 22 

Table 14 Projected Uncontrolled and Controlled (2 BMPs) Tillage Emissions in MC Portion of Area A .... 23 

Table 15 Projected Uncontrolled and Controlled Tillage Emissions in Area A (Maricopa County).............. 24 

Table 16 Projected Controlled Tillage (2 BMP) Emissions in Area A (Maricopa County) by Crop.............. 24 

Table 17 Emission Reductions from Banning Tilling on HPAs in Area A (Maricopa County) ..................... 25 

Table 18 Potential Emission Reductions from Banning Tilling from 2 AM to 8 AM on HPAs..................... 26 

Table 19 Summary of Potential Emission Reductions ................................................................................... 27 

Table 20 Percent Emission Reductions of Agricultural Control Measures in Senate Bill 1552..................... 27 

Table A-1 Potential PM10 Emission Reductions by Control Measure and Associated Crop.......... Attachment-1 

LIST OF FIGURES 

Figure 1. Ranking of Maricopa County Agricultural BMPs and San Joaquin CMPs................................ 9 
1

1.0 TECHNICAL ANALYSIS OF AGRICULTURAL BMPS 

1.1 INTRODUCTION 

This chapter presents the methodology, assumptions, and data used in selecting and assessing the 

effectiveness of agricultural best management practices (BMPs) that are not included in the current set of 

Maricopa County Agricultural PM10 Best Management Practices (Governor’s Agricultural BMP 

Committee 2001). The chapter is divided into two sections. The first section (1.2) compares the current 

Maricopa County Agricultural BMPs with the San Joaquin Valley Air Pollution Control District 

Conservation Management Practices (CMPs). The second section (1.3) summarizes potential PM10

emission reductions from agricultural BMPs listed in Senate Bill 1552: (1) Requiring growers to use one 

additional BMP per Maricopa County BMP category, and (2) Banning agricultural tilling on high 

pollution advisory days. 

1.2 COMPARISON OF MARICOPA COUNTY BMPs AND SAN JOAQUIN CMPs 

At the request of the Agricultural Best Management Practices Workgroup (2006 – 2007), ADEQ Air 

Quality Division staff performed an analysis comparing potential PM10 emissions reductions from 

implementation of San Joaquin CMPs with existing Maricopa County Agricultural BMPs for the 

Maricopa County PM10 Nonattainment Area (ADEQ 2007a). This comparison was done to determine if 

there were San Joaquin CMPs that have the potential to reduce agricultural PM10 emissions in the 

Maricopa County PM10 Nonattainment Area. The San Joaquin CMP program was selected for this 

analysis based on a literature search of other states’ agricultural control measures. 

 

The sources of data for the CMPs and BMPs: 

 “Conservation Management Practices Program Report for 2005”, San Joaquin Valley Air 

Pollution Control District, January 19, 2006; and 

 “Technical Support Document for Quantification of Agricultural Best Management Practices, 

Revised Final Draft”, ADEQ Contract No. 98-0159-BF, URS Corporation and Eastern Research 

Group, Inc., June 8, 2001. 

1.2.1 Methodology 

The following steps were used to estimate potential uncontrolled PM10 emissions and potential PM10

emission reductions from implementation of Maricopa County Agricultural BMPs and San Joaquin 

CMPs. 

1. Estimation of Crop Acres in Maricopa County PM10 Nonattainment Area (NAA): 

CropNonattainment Area = CropMaricopa County * (Ag AcresNonattainment Area / Ag AcresMaricopa County) 

Where: 

CropNAA = Area of a specific crop in the Maricopa County PM10 NAA (acres)

CropMaricopa County = Area of a specific crop in Maricopa County (acres)

(Source: USDA, Arizona Agricultural Statistics - Year 2004)

Ag AcresNAA = Total agricultural area in Maricopa County PM10 NAA (acres) 

(Source: 2004 MAG Land Use Data)

Ag AcresMaricopa County = Total agricultural area in Maricopa County (acres)

(Source: USDA, Arizona Agricultural Statistics – Year 2004)

Example - Acres of Cotton in Maricopa County PM10 NAA: 
2

Given: 

CropNAA = Acres of cotton in the Maricopa County PM10 NAA 

CropMaricopa County = 20,500 acres of cotton in Maricopa County 

Ag AcresNAA = 223,624 total agricultural acres in Maricopa County PM10 NAA

Ag AcresMaricopa County = 465,833 total agricultural acres in Maricopa County 

Then: 

CropNAA = CropMaricopa County * (Ag AcresNAA / Ag AcresMaricopa County)

CottonNAA = 20,500 acres * (223,624 acres / 465,833 acres)

CottonNAA = 20,500 acres * 0.48005 = 9,841 acres

 

2. Calculation of Uncontrolled PM10 Emissions by Crop & Agricultural Activity in Maricopa County

PM10 Nonattainment Area: 

ECrop Activity = EFCrop Activity * A

Where: 

ECrop Activity = Emissions for a specific crop and activity (lbs PM10 / year)

EFCrop Activity = Emission factor for a specific crop and activity (lbs PM10 / acre / year)

A = Area of crop (acres)

Example – Land Preparation / Cultivation for Cotton: 

Given: 

ECrop Activity = Emissions for land preparation / cultivation for cotton in Maricopa 

County PM10 Nonattainment Area (lbs PM10 / year)

EFCrop Activity = 8.90 lbs PM10 / acre / year for land preparation for cotton 

A = 9,841 acres of cotton in Maricopa County PM10 Nonattainment Area 

Then: 

ECrop Activity = EFCrop Activity * A

 = 8.90 lbs PM10 / acre / year * 9,841 acres

 = 87,585 lbs PM10 / year
3

3. Calculation of PM10 Emissions Reduction by Crop and Control Measure: 

ER = EUncontrolled Emissions * CE 

Where: 

ER = Emissions reduction for a specific crop and activity 

after application of a control measure (lbs PM10 / year)

EUncontrolled Emissions = Uncontrolled emissions for a specific crop and activity 

 (lbs PM10 / year)

CE = Control effectiveness of a specific control measure

(decimal reduction, e.g. 0.25 = 25% reduction)

Example – Integrated Pest Management Control Measure Applied to Cotton Tilling: 

Given: 

ER = Emissions reduction for cotton land preparation / cultivation tilling 

after application of Integrated Pest Management control measure 

(lbs PM10 / year) 

EUncontrolled Emissions = Uncontrolled Emissions for cotton land preparation / cultivation (lbs 

PM10 / year)

 

CE = 19% = 0.19

Then: 

ER = EUncontrolled Emissions * CE

ER = 87,585 lbs PM10 / year * 0.19

ER = 16,641 lbs PM10 / year

Table 1 lists the emission factors and adjustment factors that were used to estimate potential PM10

emissions by crop and agricultural activities for comparison of Maricopa County BMPs with San Joaquin 

CMPs. Note: the emission factors listed in Table 1 are composite emission factors that combine data from 

a number of emission generating activities into one emission factor by crop and category. For example, 

the composite emission factor for the Land Preparation / Cultivation category for Cotton combines 

emission factors for the following agricultural activities: rip field, primary discing, list beds, make ditch, 

spray and incorporate herbicide, irrigate, close ditch, cultivate preplant, plant, uncap beds, and cultivate. 

(See Table A-1 in Attachment #1 for a list of individual emission factors and emission reductions by crop 

activity, crop, and control measure.)
4

Table 1 – Emission Factors and Adjustment Factors

Unpaved Road and Unpaved 

Areas1

Crop Type Land 

Preparation1

(lbs PM10 / 

acre/yr)

Harvest1

(lbs PM10 / 

acre/yr)

Wind 

Erosion2

 Cropland

(lbs PM10 /

acre/yr)

Wind 

Erosion2

Non 

Cropland

(lbs PM10 / 

acre/yr)

Wind 

Erosion2

 Unpaved 

Roads

(lbs PM10 / 

acre/yr)

Vehicle Miles 

Traveled (VMT)1

(VMT/acre/yr)

VMT Emis

Factor

(lbs PM

VMT)

Alfalfa 4.00 0.24 0 0.33 4.31 0.40 2 Citrus 0.07 0.14 122.24 1.33 2.88 1.23 2 Corn 6.90 0.43 108.05 1.33 2.88 0.4 2 Cotton 8.90 3.37 128.84 3.33 3.60 0.4 2 Onions 6.50 1.68 122.24 1.33 2.88 2.4 2 Wheat 4.45 3.45 0 1.33 2.88 1.4 2 Barley 4.45 3.45 0 1.33 2.88 1.4 2 Lettuce 12.75 0.23 122.24 1.33 2.88 2.4 2 Melons 5.70 0.23 122.24 1.33 2.88 2.4 2 Vegetables 9.05 0.23 122.24 1.33 2.88 2.4 2 Data Sources:1“Conservation Management Practices Program Report for 2005”, San Joaquin Valley Air Pollution Control District, Januar2“Technical Support Document For Quantification Of Agricultural Best Management Practices, Final”, Prepared for Arizon

Environmental Quality by URS Corporation and Eastern Research Group, Inc., June 8, 2001.

3Vehicle Travel Emission Factor was calculated by multiplying Vehicle Miles Traveled by VMT Emission Factor.

1.2.2 Summary of Emissions Reductions The methodology used in Section 1.2.1 was used to estimate and compare the potential emission reductions that would result from 

BMPs and San Joaquin CMPs in the Maricopa County PM10 Nonattainment Area. Table 2 ranks the sixty-seven Maricopa Cou

Joaquin CMPs from largest to smallest potential PM10 emission reductions for the Maricopa County PM10 Nonattainment Area. As 

control measures that reduce wind erosion on cropland have the highest potential PM10 emission reductions, ranging from 1,034 t

per year. It should be noted that there were no wind erosion control measures in the San Joaquin CMPs. This is the reason that t

the most effective PM10 emission reductions. 

 The cross reference column in Table 2 refers to the corresponding control measure listed in Table A-1 of Attachment #1 (e.g., “C

Ridges control measure with data for its eight associated crop types). Table A-1 provides greater detail on the control measure
5

control measures, emission factors, emissions, and emissions reductions of the control measures that were evaluated. Figure 1 d

Agricultural BMPs and San Joaquin CMPs that have annual PM10 emission reductions of 10 tons or more. The Agricultural 

Governor’s Agricultural Best Management Practices Committee reviewed the comparison of the Maricopa County BMPs’ an

reductions and the Committee selected six control measures based on their feasibility and potential emission reductions. Caveat: The emissions and emissions reduction data listed in this section are for comparison purposes only to evaluate the poagricultural control measures. These data should not be construed as an emissions inventory for agricultural operations since number of acres by crop in the Maricopa County PM10 Nonattainment Area and make general assumptions about the application of 

Table 2 - Ranking of PM10 Emission Reductions From Maricopa County Agricultural BMPs and San Joa

Organization Control Measure Category

Cross 

Reference 

to Table 

A-1 Control Measure

1 Maricopa County BMP Cropland - Other Activities CO-8 Cross-Wind Ridges (reduces wind erosion on cropland) 2 Maricopa County BMP Cropland - Other Activities CO-28 Surface Roughening (reduces wind erosion of cropland) 3 Maricopa County BMP Cropland - Other Activities CO-30a Wind Barrier – Artificial (reduces wind erosion of cropland) 4 Maricopa County BMP Cropland - Other Activities CO-30b Wind Barrier – Natural (reduces wind erosion of cropland) 5 San Joaquin CMP Cropland - Other Activities CO-11 Grinding / Chipping / Shredding 6 San Joaquin CMP Cropland - Other Activities CO-26 Soil Incorporation 7 Maricopa County BMP Cropland - Other Activities CO-24 Sequential Cropping 8 Maricopa County 

BMP

Unpaved Roads & Non Cropland 

CU-8

Wind Barrier - Artificial (reduces wind erosion of unpaved roads and non cropland) 

9 Maricopa County BMP Cropland - Land Prep / Cultivation CL-6 Conservation Tillage 

10 Maricopa County BMP Cropland - Land Prep / Cultivation CL-21 Time of Planting 11 San Joaquin CMP Unpaved Roads & Non Cropland CU-3 Paving 12 San Joaquin CMP Cropland - Other Activities CO-1 Alternate Tilling 13 Maricopa County BMP Cropland - Land Prep / Cultivation CL-8 Equipment Changes/Technological Improvement
6

Table 2 - Ranking of PM10 Emission Reductions From Maricopa County Agricultural BMPs and San Joa

Organization Control Measure Category

Cross 

Reference 

to Table 

A-1 Control Measure

14 Maricopa County BMP Unpaved Roads & Non Cropland CU-6 Track Out Control 15 San Joaquin CMP Unpaved Roads & Non Cropland CU-1d Road Oil 16 San Joaquin CMP Unpaved Roads & Non Cropland CU-1c Polymers 17 Maricopa County BMP Unpaved Roads & Non Cropland CU-7 Water Application 18 Maricopa County 

BMP

Unpaved Roads & Non Cropland 

CU-9

Wind Barrier – Natural(reduces wind erosion of unpaved roads and non cropland) 

19 Maricopa County BMP Cropland - Other Activities CO-15 Mulching 20 San Joaquin CMP Cropland - Other Activities CO-25 Soil Amendments 21 San Joaquin CMP Unpaved Roads & Non Cropland CU-1f Gravel 22 San Joaquin CMP Cropland - Land Prep / Cultivation CL-17 Organic Practices 23 San Joaquin CMP Cropland - Other Activities CO-20 Organic Practices 24 Maricopa County BMP Unpaved Roads & Non Cropland CU-5a-d Reducing speed on unpaved roads 25 Maricopa County BMP Cropland – Harvest CH-4 Equipment Changes/Technological Improvement26 Maricopa County BMP Cropland - Land Prep / Cultivation CL-12 Limited Activity During a High-Wind Event 27 Maricopa County BMP Cropland - Other Activities CO-16 Multi-Year Crop 28 San Joaquin CMP Unpaved Roads & Non Cropland CU-1a Chips/mulch 29 San Joaquin CMP Unpaved Roads & Non Cropland CU-1b Organic materials/vegetation 30 San Joaquin CMP Unpaved Roads & Non Cropland CU-1e Sand 
7

Table 2 - Ranking of PM10 Emission Reductions From Maricopa County Agricultural BMPs and San Joa

Organization Control Measure Category

Cross 

Reference 

to Table 

A-1 Control Measure

31 San Joaquin CMP Cropland – Land Prep / Cultivation CL-19 Precision Farming 32 San Joaquin CMP Cropland - Land Prep / Cultivation CL-20 Tillage Based on Soil Moisture 33 San Joaquin CMP Cropland - Other Activities CO-12 Integrated Pest Management 34 San Joaquin CMP Cropland - Other Activities CO-2 Application Efficiencies 35 San Joaquin CMP Cropland - Other Activities CO-29 Transgenic Crops 36 San Joaquin CMP Cropland - Land Prep / Cultivation CL-5 Conservation Irrigation 37 San Joaquin CMP Cropland - Other Activities CO-6 Conservation Irrigation 38 San Joaquin CMP Cropland - Land Prep / Cultivation CL-2 Bed/Row Size or Spacing 39 Maricopa County BMP Cropland - Land Prep / Cultivation CL-14 Multi-Year Crop 40 San Joaquin CMP Cropland - Land Prep / Cultivation CL-15 Night Farming 41 Maricopa County BMP Cropland – Harvest CH-2 Combined Operations 42 San Joaquin CMP Cropland – Harvest CH-14 Shuttle System / Larger Carrier 43 San Joaquin CMP Cropland – Harvest CH-7 Green Chop 44 San Joaquin CMP Cropland - Land Prep / Cultivation CL-13 Mulching 45 Maricopa County BMP Cropland - Land Prep / Cultivation CL-22 Timing of Tillage Operation 46 San Joaquin CMP Cropland - Land Prep / Cultivation CL-23 Transgenic Crops 47 San Joaquin CMP Cropland - Land Prep / Cultivation CL-11 Integrated Pest Management 48 Maricopa County BMP Cropland - Land Prep / Cultivation CL-4 Combining land preparation operations49 San Joaquin CMP Cropland - Land Prep / Cultivation CL-3 Chemigation/Fertigation50 San Joaquin CMP Cropland - Other Activities CO-5 Chemigation/Fertigation
8

Table 2 - Ranking of PM10 Emission Reductions From Maricopa County Agricultural BMPs and San Joa

Organization Control Measure Category

Cross 

Reference 

to Table 

A-1 Control Measure

51 San Joaquin CMP Cropland – Harvest CH-1 Baling/Large Balers 52 San Joaquin CMP Cropland - Other Activities CO-3 Baling/Large Balers 53 Maricopa County BMP Cropland - Other Activities CO-23 Residue Management 54 San Joaquin CMP Unpaved Roads & Non Cropland CU-4 Restricted Access 55 San Joaquin CMP Cropland - Land Prep / Cultivation CL-16 Non-Tillage/Chemical Tillage 56 San Joaquin CMP Cropland - Other Activities CO-19 Non-Tillage/Chemical Tillage 57 San Joaquin CMP Cropland – Harvest CH-9 Night Harvesting 58 Maricopa County BMP Cropland – Harvest CH-12 Reduced Harvest Activity 59 San Joaquin CMP Cropland - Other Activities CO-17 Night Farming / Night Harvesting 60 San Joaquin CMP Cropland – Harvest CH-11 Pre-Harvest Soil Preparation 61 San Joaquin CMP Cropland - Land Prep / Cultivation CL-24 Transplanting 62 San Joaquin CMP Cropland – Harvest CH-8 Hand Harvesting 63 San Joaquin CMP Cropland – Harvest CH-13 Shed Packing 64 Maricopa County BMP Cropland - Land Prep / Cultivation CL-7 Cover Crops 65 San Joaquin CMP Cropland - Other Activities CO-7 Cover Crops 66 San Joaquin CMP Cropland - Other Activities CO-22 Reduced Pruning 67 Maricopa County BMP Cropland - Land Prep / Cultivation CL-18 Planting Based on Soil Moisture 
9

Figure 1. Ranking of Maricopa County Agricultural BMPs and San Joaquin CMPs

Ranking of Maricopa County BMPs and San Joaquin CMPs

PM10 Emission Reductions (Tons/Year)

0 100 200 300 400 500 600 700 8

Cross-Wind Ridges (reduces w ind erosion on cropland): Surface Roughening (reduces w ind erosion of cropland): Wind Barrier - Artificial (reduces w ind erosion of cropland): Wind Barrier - Natural (reduces w ind erosion of cropland): Grinding / Chipping / Shredding: Soil Incorporation: Sequential Cropping: Wind Barrier - Artificial (reduces w ind erosion of unpaved Conservation Tillage: Time of Planting: Paving: Alternate Tilling: Equipment Changes/Technological Improvements: Track Out Control:

Road Oil:

Polymers: Water Application: Wind Barrier - Natural (reduces w ind erosion of unpaved Mulching: Soil Amendments:

Gravel:

Organic Practices: Organic Practices: Reducing speed from 25. 9 mph to 5 mph: Reducing speed from 25.9 mph to 10 mph: Reducing speed from 25.9 mph to 15 mph: Reducing speed from 25.9 to 25 mph: Equipment Changes/Technological Improvements: Limited Activity During a High-Wind Event: Multi-Year Crop: Chips/mulch: Organic materials/vegetation: Sand:

Precision Farming: Tillage Based on Soil Moisture: Integrated Pest Management: Application Efficiencies: Transgenic Crops: Conservation Irrigation: Conservation Irrigation: Bed/Row Size or Spacing: Multi-Year Crop: Night Farming: Combined Operations: Shuttle System / Larger Carrier: Green Chop: Mulching: Timing of Tillage Operation: Transgenic Crops: Integrated Pest Management:
10

1.3 AGRICULTURAL BMPS IN SENATE BILL 1552 

ADEQ Air Quality Division staff performed an analysis to estimate potential PM10 emissions reductions 

from agricultural BMPs language contained in Senate Bill 1552 (2007 session). Specifically, the 

following two agricultural BMPs were evaluated: (1) Expanding the number of Best Management 

Practices (BMPs) that growers must apply from one to two for each of the three BMP categories and 

extending the applicability of the Maricopa County BMPs to the Maricopa County portion of Area A 

outside of the Maricopa County PM10 Nonattainment Area, and (2) Implementing a ban on tillage in Area 

A on any day for which ADEQ has issued a High Pollution Advisory. 

1.3.1 Effect of One Additional Agricultural BMP in Maricopa County PM10 Nonattainment Area 

The following section discusses the methodology, data, and assumptions used to estimate potential PM10

emissions reductions in the Maricopa County PM10 Nonattainment Area (NAA) from requiring growers to 

apply one additional agricultural BMP per category listed in the Maricopa County Agricultural BMPs. 

The section is arranged by the steps used to estimate the potential PM10 emission reductions. 

 

1. Percent Emission Reduction by Agricultural BMP Category - The percent emission reductions for the 

following three Agricultural BMP categories - Tillage & Harvest, Non-cropland (Unpaved Farm 

Roads), and Cropland (Windblown Agriculture) were estimated for the NAA for Year 2005 using the 

following methodology: 

Tillage & Harvest BMPs and Non-cropland / Unpaved Farm Roads BMPs 

The Maricopa County Air Quality Department’s (MCAQD) 2005 Periodic PM10 Emission Inventory 

(PEI) lists annual uncontrolled and controlled PM10 emissions from tillage and harvest operations, and 

travel on unpaved agricultural roads in Maricopa County. MCAQD used the BMP control efficiencies 

listed in Table 4-2 of the URS and ERG report: “Technical Support Document of Agricultural Best 

Management Practices, June 2001” to calculate controlled PM10 emissions for tillage, harvest, and 

unpaved farm roads. However, MCAQD used a compliance rate of 59 percent rather than the 80 

percent listed in the URS and ERG report. The 59 percent compliance rate was used to ensure 

consistency with MCAQD’s rule effectiveness study of the agricultural BMPs that was used in the 

development of the MCAQD 2005 PEI. 

The percent emission reduction for the Tillage & Harvest BMPs and the Non-cropland / Unpaved Farm 

Roads BMPs were calculated as follows: 

% BMP ReductionAg Source = (Uncontrolled EmissionsAg Source - Controlled EmissionsAg Source) / Uncontrolled EmissionsAg Source 

Where: 

% BMP ReductionAg Source = Percent reduction in PM10 emissions from application of one agricultural BMP. 

Uncontrolled EmissionsAg Source = Uncontrolled PM10 emissions from agricultural source without agricultural BMP. 

(Source: MCAQD 2005 PEI) 

 Controlled EmissionsAg Source = Controlled PM10 emissions from agricultural source with one agricultural BMP. 

(Source: MCAQD 2005 PEI) 
11

Example - Percent Emission Reduction from Tillage BMPs – Year 2005: 

Given: 

Uncontrolled EmissionsTillage = 1,556 tons PM10 / year 

Note: Agricultural emissions in NAA = Maricopa County agricultural emissions * 

48.005% ( Percent of Maricopa County agricultural land in NAA) 

 Controlled EmissionsTillage = 1,229 tons PM10 / year 

 Then: 

 % BMP ReductionTillage = (Uncontrolled EmissionsTillage - Controlled EmissionsTillage) / Uncontrolled 

EmissionsTillage 

 

 = (1,556 tons / year - 1,229 tons / year) / 1,556 tons 

 = 21.0% 

 

The percent emission reductions for Harvest BMPs and Non-cropland BMPs were calculated in a 

similar fashion to the percent emission reduction for tillage. A weighted average percent emission 

reduction was calculated for the Tillage & Harvest BMP category based on the percent emission 

reductions calculated for Tillage BMPs and Harvest BMPs . 

 

Cropland / Windblown Agriculture BMPs 

The percent emission reduction for the Cropland / Windblown Agriculture BMP category was derived 

from the Maricopa Association of Government’s (MAG) technical support document: “Technical 

Support Document in Support of the MAG 2007 Five Percent Plan for PM10 for the Maricopa County 

Nonattainment Area”. MAG used the U.S. Department of Agriculture’s (USDA) wind erosion 

equation to calculate PM10 emissions from wind erosion of agricultural fields in Maricopa County and 

in the Maricopa County PM10 Nonattainment Area. Hourly wind speeds and annual totals of harvested 

acres by crop in Maricopa County were input to the USDA wind erosion equation for years 2001 

through 2005 to produce estimates of annual PM10 emissions. A five-year average of the annual PM10

emissions due to Cropland / Windblown Agriculture was then calculated. 

Table 3 lists the emissions and percent emission reductions for the three agricultural BMP categories. 

Table 3 - Calculation of Percent PM10 Emission Reductions by Ag BMP Group

Agricultural BMP Group Maricopa 

County

Year 2005

% County Ag 

Land in 

PM10 NAA1

PM-10 NAA 

Year 2005

Tillage:

Uncontrolled tillage emissions (tons/year)1 3,241.12 48.005% 1,555.90

Controlled tillage emissions (tons/year)1 1,228.67

Emission Reduction (tons/year) 327.23

Percent Reduction due to one Tillage BMP 21.0%

Harvest:

Uncontrolled harvest emissions (tons/year)1 166.36 48.005% 79.86

Controlled harvest emissions (tons/year)1 58.99

Emission Reduction (tons/year) 20.87

Reduction due to one Harvest BMP 26.1%
12

Table 3 - Calculation of Percent PM10 Emission Reductions by Ag BMP Group

Agricultural BMP Group Maricopa 

County

Year 2005

% County Ag 

Land in 

PM10 NAA1

PM-10 NAA 

Year 2005

Tillage & Harvest:

% Weighted reduction for one Tillage & 

Harvest BMP

21.3%

Non-cropland / Unpaved Farm Roads:

Uncontrolled farm road emissions (tons/year)1 2,175.39 48.005% 1,044.30

Controlled farm road emissions (tons/year)1 910.64

Emission Reduction (tons/year) 133.66

% Reduction due to one Non-Cropland BMP 12.8%

Cropland / Windblown Agriculture:

Uncontrolled windblown agricultural 

emissions (tons/year)2

1,614

Controlled windblown agricultural emissions 

tons/year)2

1,128

Emission Reduction (tons/year) 486

% Reduction due to one Cropland BMP3 30.1%

 

Data Sources: 1

“2005 Periodic PM10 Emission Inventory”, MCAQD, May 2007. 

2

"Technical Support Document in Support of the MAG 2007 Five Percent Plan for PM10 for the Maricopa 

County Nonattainment Area", Maricopa Association of Governments, December 2007. (Windblown 

agricultural emissions were derived from data in the MAG 2007 TSD's Appendix II, Exhibit 3: "Windblown 

Dust Emission Calculations for PM10 Nonattainment Are for the Years 2001 - 2005".) 

3

Derived from Table 4-2 of the "Technical Support Document for Quantification of Agricultural Best 

Management Practices, Revised Final Draft", ADEQ Contract No. 98-0159-BF. URS Corporation and 

Eastern Research Group, Inc., June 8, 2001. Note: The compliance rate of 0.80 listed in the TSD for 

Quantification of Ag BMPs was converted to 0.59 by MCAQD in the development of their 2005 PEI. 

2. Projected Crop Acreage in Maricopa County 

The Arizona Agricultural Statistics Bulletins for years 2000 through 2004 were reviewed to 

determine trends in crop acreages in Maricopa County. Based on these crop acreage data, the trend 

for harvested acres of field crops is a 4.6 percent decline per year and the trend for harvested acres of 

all crops (includes grapes and citrus) is a 4.9 percent decline per year. These annual trends were 

used to project years 2007 through 2010 crop acreage for field crops (-4.6% per year) and all crops (-

4.9% per year) as follows: 

Example – Field Crop Acreage – Year 2006: 

Projected Crop Acres = Year 2005 Crop Acres x Annual Decrease 

Projected Crop Acres Field Crops = 172,340 Harvested Acres Field Crops x (1 - 0.046) 

= 164,412 Harvested Acres Field Crops in 2006 
13

Table 4 lists historical and projected crop acreage for Maricopa County. 

Table 4 - Historical and Projected Crop Acreage in Maricopa County (acres / year)

2003 2004 2005 2006 2007 2008 2009 2010

Harvested 

Acres of 

Field 

Crops1

169,750 180,650 172,340 164,412 156,849 149,634 142,751 136,184

Harvested 

Acres of 

All 

Crops2

179,050 189,950 180,642 171,791 163,373 155,368 147,755 140,515

Data Sources:

1

Based on data from 2000-2004 Arizona Agricultural Statistics Bulletins; excludes grapes & citrus. 

Average annual acreage decrease between 2000 and 2004 = -4.6%. 

2

Based on data from 2000-2004 Arizona Agricultural Statistics Bulletins; includes grapes & citrus; 

average annual acreage decrease between 2000 and 2004 = -4.9%. 

3. Rate of Change Factors 

The years 2007 through 2010 projected crop acreage for harvested acres of field crops and harvested 

acres of all crops (Table 4) were divided by year 2005 crop acreage to produce rate of change factors 

for years 2006 through 2010 for harvested acres of field crops and harvested acres of all crops as 

follows: 

Example – Rate of Change for Field Crops – Year 2006: 

Rate of Change Factor = Year 2006 Crop Acres / Year 2005 Crop Acres 

Rate of Change Factor Field Crops = 164,412 Harvested Acres Field Crops / 172,340 Harvested Acres Field Crops 

 = 0.954 for 2006 

Table 5 lists rate of change factors for years 2006 through 2010. 

Table 5 - Rate of Change Factors for Agricultural Land in Maricopa County

2006 2007 2008 2009 2010

Harvested Acres of Field Crops 

● Used to estimate future emission reductions 

from 2nd additional Tillage & Harvest BMP. 

● Year 2005 is base year for calculation.

0.954 0.910 0.868 0.828 0.790

Harvested Acres of All Crops 

● Used to estimate future emission reductions 

from 2nd additional Noncropland / Unpaved 

Farm Roads BMP.

● Year 2005 is base year for calculation.

0.951 0.904 0.860 0.818 0.778

Harvested Acres of Field Crops 

● Used to estimate future emission reductions 

from 2nd additional Cropland / Windblown Ag 

BMP. 

● Year 2003 is base year for calculation.

0.969 0.924 0.881 0.841 0.802

 
14

4. Projected Agricultural Emissions in Maricopa County PM10 Nonattainment Area 

The year 2005 uncontrolled emissions and controlled emissions (Table 3, based on MCAQD 2005 

PEI) were multiplied by the rate of change factors (Table 5) to produce projected uncontrolled and 

controlled emission reductions, by agricultural BMP category, for years 2006 through 2007. The 

following rate of change factors were used to estimate projected and controlled emissions: (1) 

“Harvested Acres of Field Crops” rate of change factor was used for the Tillage & Harvest BMPs, (2) 

“Harvested Acres of All Crops” rate of change factor was used for the Non-cropland / Unpaved Farm 

Roads BMPs, and (3) “Harvested Acres of Field Crops (base year 2003),” rate of change factor was 

used for the Cropland / Windblown Agriculture BMPs. These emissions are listed in Table 6 and the 

following example shows the calculation of projected emissions. 

Example – Uncontrolled Tillage & Harvest Emissions – Year 2006: 

Projected Emissions = Year 2005 Emissions x Rate of Change Factor 

Projected Emissions Tillage & Harvests = 1,636 tons / year Uncontrolled Tillage & Harvest x 0.954 

 = 1,561 tons / year Uncontrolled Tillage & Harvest 

Table 6 - PM10 Emissions for Maricopa County PM10 Nonattainment Area (tons / year)

BMP Category 2005 2006 2007 2008 2009 2010

Tillage & Harvest:

 Uncontrolled 1,636 1,561 1,489 1,420 1,355 1,292

 Controlled (21.3% reduction) 1,288 1,229 1,172 1,118 1,066 1,018

Non-cropland / Unpaved Farm Roads:

 Uncontrolled 1,044 993 944 898 854 812

 Controlled (12.8% reduction) 911 866 824 783 745 709

Cropland / Windblown Agriculture:

 Uncontrolled 1,614 1,564 1,491 1,422 1,357 1,294

 Controlled (30.1% reduction) 1,128 1,093 1,042 994 949 905

5. Projected Agricultural Emission Reductions in Maricopa County PM10 Nonattainment Area

 One Agricultural BMP - The uncontrolled agricultural emissions (Table 6) for years 2006 

through 2010 were multiplied by the percent emission reductions for the three agricultural BMP 

categories (Table 1: Tillage & Harvest = 21.3%, Non-cropland / Unpaved Farm Roads = 12.8%, 

Cropland / Windblown Agriculture = 30.1%) The resulting emission reductions represent the 

application of one agricultural BMP per BMP category. These emission reductions are listed in 

Table 7 and the following example shows the calculation of the emission reductions. 

Example – Tillage & Harvest Emissions Reduction – Year 2006: 

Emission Reductions = Annual Emissions x % BMP Emission Reduction 

Emissions ReductionTillage & Harvest = 1,561 tons / year Uncontrolled Tillage & Harvest x 0.213 

 = 332 tons / year 
15

 Second Additional Agricultural BMP – Years 2006 through 2010 controlled agricultural 

emissions (Table 6) were multiplied by the percent emission reductions for the three agricultural 

BMP categories (Table 3). The resulting emission reductions represent the application of a 

second additional agricultural BMP per BMP category. These emission reductions are listed in 

Table 7. 

It was assumed that the control effectiveness of the second additional agricultural BMP per BMP 

category would be at least as effective as the first set of agricultural BMPs. It should be noted 

that the percent emission reductions for the second additional BMP were applied to controlled

agricultural emissions to account for the emission reductions that had already occurred from 

application of the first set of agricultural BMPs to the uncontrolled agricultural emissions. 

 Total Agricultural Emission Reductions – The above emission reductions resulting from 

application of the first agricultural BMP and the second additional agricultural BMP for each of 

the three agricultural BMP categories (Tillage & Harvest, Non-cropland / Unpaved Farm Roads, 

Cropland / Windblown Agriculture) were summed to give total agricultural emission reductions 

for years 2006 through 2010, by BMP category, for the Maricopa County PM10 Nonattainment 

Area. These emission reductions are listed in Table 7. 

Table 7 - Emission Reductions for Maricopa County PM10 Nonattainment Area (tons/year)

BMP Category 2005 2006 2007 2008 2009 2010

Tillage & Harvest:

 First BMP Applied 348 332 317 303 289 275

 Second BMP Applied 274 262 250 238 227 217

 Total 622 594 567 541 516 492

Non-cropland / Unpaved Farm Roads:

 First BMP Applied 134 127 121 115 109 104

 Second BMP Applied 117 111 105 100 95 91

 Total 251 238 226 215 204 195

Cropland / Windblown Agriculture:

 First BMP Applied 486 471 449 428 408 389

 Second BMP Applied 340 329 314 299 286 272

 Total 826 800 763 727 694 661

Notes:

1. PM10 Emission Reduction from 1st Ag BMP = % Emission Reduction * Uncontrolled Emissions (e.g., Year 

2005 Tillage & Harvest: 1,636 tons PM10 / Year 2005 * 21.3% = 348 tons PM10 reduced / Year 2005). 

2. It was assumed that the control effectiveness of requiring that a second BMP be implemented for each of the 

three BMP categories - Tillage & Harvest, Cropland, and Noncropland - would be at least as effective in reducing 

PM10 emissions as implementing the first set of BMPs for each of the three BMP categories. 

3. PM10 Emission Reduction from 2nd Ag BMP = % Emission Reduction * Controlled Emissions after 1st Ag 

BMP has been implemented (e.g., Year 2007 Tillage & Harvest: 1,172 tons PM10 / year * 21.3% = 250 tons PM10

reduced / year). 
16

1.3.2 Extending Agricultural BMP Program to Maricopa County Portion of Area A outside the 

Maricopa County PM10 Nonattainment Area 

The following section discusses the methodology, data, and assumptions used to estimate potential PM10

emission reductions for the Maricopa County portion of Area A outside of the Maricopa County PM10

Nonattainment Area (hereafter referred to as “MC Portion of Area A”) of requiring growers to apply two 

agricultural BMPs per category. The rationale for evaluating the effect of two agricultural BMPs per 

category for the MC Portion of Area A is that this area had previously not been subject to the Agricultural 

BMP Program (only the Maricopa County PM10 Nonattainment Area had been subject to the Agricultural 

BMP Program). The section is arranged by the steps used to estimate the potential PM10 emission 

reductions and will build on the agricultural emission reduction data that were calculated in the previous 

section for the Maricopa County PM10 Nonattainment Area. 

1. Percent Agricultural Land In Maricopa County - The percent agricultural land in Maricopa County 

was calculated by dividing the total acres of agricultural land in Maricopa County, listed in the 2004 

Arizona Agriculture Statistics Bulletin for Maricopa County, by the total acres of land in Maricopa 

County as follows: 

Example – Percent Agricultural Land: 

Percent Ag Land in County = Total Ag Acres in County / Total Acres in County 

= 189,950 acres / 5,889,941 acres 

 = 3.225% 

2. Land in MC Portion of Area A - Spatial analysis, using GIS, was used to determine the number of 

acres in the MC Portion of Area A and the percentage of the MC Portion of Area A in Maricopa 

County. The results of the GIS analysis were that there are 806,333 acres in the MC Portion of Area 

A and the percentage of the MC Portion of Area A that is in Maricopa County is 13.69% (based on 

spatial analysis by ADEQ GIS staff). 

 

3. Agricultural Land in MC Portion of Area A – Was calculated by multiplying “Percent Agricultural 

Land in Maricopa County” (Step #1) by “Land in MC Portion of Area” (Step #2) as follows: 

Example – Agricultural Land in MC Portion of Area A: 

 Ag Land in MC Portion of Area A = Percent Ag Land in County x Land in MC Portion of Area A 

 = 3.225% x 806,333 acres 

 = 26,004 acres 
17

4. Agricultural Land in Maricopa County PM10 Nonattainment Area - Was calculated by multiplying 

the “Percent County Agricultural Land in Maricopa County PM10 Nonattainment Area” (MCAQD, 

2007) by total agricultural acres in Maricopa County (USDA, 2005) as follows: 

Example – Agricultural Land in Maricopa County PM10 Nonattainment Area: 

Ag Land in PM10 Nonattainment Area = Percent County Ag Land in NAA x Ag Land in Maricopa County 

= 48.005% x 189,950 acres 

 = 91,185 acres 

 

5. Ratio of Agricultural Land in MC Portion of Area A to Agricultural Land in Maricopa County 

PM10 Nonattainment Area – Was calculated by dividing acres of “Agricultural Land in MC Portion 

of Area A” (Step #3) by acres of “Agricultural Land in Maricopa County PM10 Nonattainment Area” 

(Step #4) as follows: 

Example – Ratio of Agricultural Land: 

Ratio of Ag Land = Ag Land in MC Portion of Area A / Ag Land in PM10 Nonattainment Area 

= 26,004 acres / 91,185 acres 

 = 0.285 

 

6. Projected Emission Reductions in MC Portion of Area A – The agricultural emission reductions 

resulting from application of the first BMP and the second additional BMP, by agricultural BMP 

category, in the Maricopa County PM10 Nonattainment Area for years 2008 through 2010 (totals 

shown in Table 7) were multiplied by the ratio of agricultural land (Step #5) to produce projected 

agricultural emission reductions for the MC Portion of Area A for years 2008 through 2010. It 

should be noted that the MC Portion of Area A was not previously subject to the Maricopa County 

Agricultural BMP program. That is the reason that both the first agricultural BMP and the second 

additional agricultural BMP, per BMP category, were applied to the MC Portion of Area A to 

estimate emission reductions. 

The projected emission reductions for the MC Portion of Area A were calculated as follows: 

MC Portion Area A ERAg Source = Nonattainment Area ERAg Source x Ratio of Ag Land 

 
18

Where: 

 MC Portion Area A ERAg Source = Emission reduction, by agricultural source (Tillage & Harvest, Noncropland / Unpaved Farm Roads, Cropland / Windblown Agriculture), in the 

Maricopa County Portion of Area A Outside of the Maricopa County PM10

Nonattainment Area. 

 Nonattainment Area ERAg Source = Emission reduction, by agricultural source (Tillage & Harvest, Noncropland / Unpaved Farm Roads, Cropland / Windblown Agriculture), in the 

Maricopa County PM10 Nonattainment Area. Note: These are total 

emission reductions due to application of original one agricultural BMP per 

category and application of second additional agricultural BMP category 

(Second agricultural BMP required by Senate Bill 1552). 

 Ratio of Ag Land = Ag Land in MC Portion of Area A / Ag Land in PM10 Nonattainment Area. 

Example - Emission Reduction from Tillage & Harvest BMP for Year 2008: 

Given: 

Nonattainment Area ERTillage & Harvest = 541 tons / year 

Ratio of Ag Land = 0.285 

Then: 

MC Portion Area A ERTillage & Harvest = Nonattainment Area ERTillage & Harvest x Ratio of Ag Land 

= 541 tons / year x 0.285 

= 154 tons / year 

Table 8 lists the emission reductions for the MC Portion of Area A, by BMP category, for the years 2008 

through 2010. 

Table 8 - Emission Reductions for MC Portion of Area A (tons/year)

2008 2009 2010

Ag BMP Category 

(1st and 2nd BMPs)

Nonattainmen

t 

Area 

Area A 

Outside 

NAA 

Nonattainment 

Area 

Area A 

Outside 

NAA 

Nonattainmen

t 

Area 

Area A 

Outside 

NAA 

Tillage & Harvest 541 154 516 147 492 140 

Non-cropland / 

Unpaved Farm Roads 

215 61 204 58 195 56 

Cropland / Windblown 

Agriculture 

727 207 694 198 661 188 

Notes:

1. It was assumed that the crop mix is homogeneous throughout Maricopa County. 

2. Emission reduction in MC Portion of Area A = NAA Emission Reduction * (Ag land in MC Portion of Area A / 

Ag land in NAA). 

3. Emission reductions in Nonattainment Area (for this table) = Emission Reduction from First BMP + Emission 

Reduction from Second BMP (see totals for each BMP category in Table 7). This assumption was used in calculating 

the MC Portion of Area A emissions because the MC Portion of Area A had not previously been subject to the 

Agricultural BMP program (only the Maricopa County PM10 Nonattainment Area had the Ag BMP Program), thus its 

projected emission reductions are due to two "additional" Ag BMPs, instead of just one additional Ag BMP, when 

extending the Agricultural BMP program to the MC Portion of Area A. 
19

7. Emission Reductions Due to Revised Agricultural BMP Program in Senate Bill 1552 - The Senate 

Bill 1552 revisions to the Agricultural BMP Program included: (a) Second additional Agricultural 

BMP in the Maricopa County PM10 Nonattainment Area, and (b) Extending the Agricultural BMP 

Program to the Maricopa County Portion of Area A Outside of the Maricopa County PM10

Nonattainment Area (two new agricultural BMPs). To determine the total projected emission 

reductions from the revised Agricultural BMP Program, the projected emission reductions for the 

MC Portion of Area A (see “Area A Outside NAA” columns in Table 8) were added to the projected 

emission reductions for the Maricopa County PM10 Nonattainment Area (see “Second BMP Applied” 

rows in Table 7). The total PM10 emission reductions due to the revised agricultural BMP program in 

Senate Bill 1552 were calculated as follows: 

Example – Emission Reductions from Tillage & Harvest BMP for Year 2008: 

ERTillage & Harvest = MC Portion of Area A ERTillage & Harvest + Nonattainment Area ERTillage & Harvest 

 = 154 tons/year + 238 tons/year

 = 392 tons/year

Table 9 lists the total projected emission reductions from the revised agricultural BMP program in Senate 

Bill 1552: (1) Second additional agricultural BMP in the Maricopa County PM10 Nonattainment Area, 

and (2) Extending the Agricultural BMP program from the Maricopa County PM10 Nonattainment Area to 

the Maricopa County portion of Area A outside of the Maricopa County PM10 Nonattainment Area. 

Table 9 – Emission Reductions from Agricultural BMP Program in Senate Bill 1552 (tons/year)

Ag BMP Category 2008 2009 2010

Tillage & Harvest BMP (21.3% Reduction) 392 374 357 

Non-cropland / Unpaved Farm Roads BMP (12.8% Reduction) 161 153 147 

Cropland / Windblown Agriculture BMP (30.1% Reduction) 506 484 460 

Total Emission Reductions: 

1. Maricopa County PM10 Nonattainment Area (one new BMP for this area). 

2. MC Portion of Area A (two new BMPs for this area).

1,059 1,011 964 

 

Emission Reductions from 2nd BMP in Maricopa County PM10 NAA 637 608 580 

Emission Reductions from 1st BMP and 2nd BMP in MC Portion of Area A 422 403 384 

Notes: 

Revised Agricultural BMP Program in Senate Bill 1552 included: 

 Maricopa County PM10 NAA - Second additional Ag BMP per category. 

 Extending Agricultural BMP program from Maricopa County PM10

Nonattainment Area to MC Portion of Area A (i.e., require two new 

BMPs per category in MC Portion of Area A). 

Projected Emission Reductions = (Emission Reductions for MC Portion of Area 

A) + (Emission Reductions for Maricopa County PM10 Nonattainment Area).

 
20

Caveats: 

1. Crop Data - The actual number of acres for specific crops in the Maricopa County PM10

Nonattainment Area and Area A is not available. These data were estimated from the Maricopa 

County crop acre data listed in the USDA, “Arizona Agricultural Statistics – 2004”. The crop 

mix was assumed to be homogeneous in the Maricopa County PM10 Nonattainment Area and MC 

Portion of Area A. 

2. Selection of Agricultural BMPs – The actual BMPs that have been selected by growers in the 

Maricopa County PM10 Area are not known since growers are not required to submit these data to 

government agencies. Thus, MCAQD assumed an average PM10 emission reduction for each 

BMP category during the development of the MCAQD 2005 Periodic PM10 Emissions Inventory.

1.3.3 Cessation of Night Tillage on High Pollution Advisory Days 

This control measure bans agricultural tilling from 2 AM to 8 AM on High Pollution Advisory Days 

(HPAs) forecast by ADEQ that are air stagnation days. The following section discusses the methodology, 

data, and assumptions used to estimate potential PM10 emission reductions from implementation of this 

control measure in the Maricopa County portion of Area A [hereafter referred to as “Area A (Maricopa 

County)”]. The section is arranged by the steps used to estimate the potential PM10 emission reductions 

and will build on the agricultural emissions and emission reduction data that were calculated in the 

previous sections for the Maricopa County PM10 Nonattainment Area and MC Portion of Area A. 

1. Comparison of Occurrence of Stagnation Days with Tillage Days for Maricopa County - The crop 

calendar of agricultural practices in Maricopa County, listed in the in the Salt River PM10 Technical 

Support Document (ADEQ, 2005), was compared with the Year 2005 – 2006 ADEQ summary report 

of PM10 exceedances and associated weather conditions (ADEQ, 2007b) to determine which crops 

were being tilled during months with stagnation days. The comparison showed that cotton, corn, and 

vegetables were being tilled during the months of January and February which have stagnation days. 

Table 10 lists data on the months when tillage and stagnation days occur and the percent of 

stagnation days that occur during tillage days by crop. 

Table 10 - Year 2005 Stagnation Days and Potential Tillage Days in Maricopa County

Crop Tillage 

Months1

Potential 

Tillage 

Days 

Stagnation 

Days2

Stagnation Days / 

Tillage Days 

(percent) 

Cotton January, February, March 59 9 15% 

Corn January, February 59 9 15% 

Vegetable

s 

February 28 5 18% 

Data Sources:

1

Crop Calendar in ADEQ Salt River PM10 TSD (ADEQ. 2005. Revised PM10 State Implementation Plan for the 

Salt River Area, Technical Support Document. Air Quality Division, Arizona Department of Environmental 

Quality. September 2005. http://azdeq.gov/environ/air/plan/download/sr-tsd.pdf). 2

ADEQ analysis of the occurrence of Stagnation Days in Year 2005: 4 days in January, 5 days in February , 0 days 

in March (ADEQ. 2007b. 2005-2006 Forecast Season PM10 Exceedance Report for Maricopa County. Air Quality 

Division, Arizona Department of Environmental Quality. January 2007). 

Notes: 

1. Potential Tillage Days: There were no stagnation days listed for March in ADEQ's analysis (only in January 

and February), that is why 59 instead of 90 "Potential Tillage Days" were considered for cotton tillage emissions. 

2. Stagnation Days: Total stagnation days were based on January and February stagnation days since ADEQ's 

analysis did not list any stagnation days for March. 
21

2. Uncontrolled Tillage Emissions in NAA for Year 2005 - Were calculated by multiplying the annual 

uncontrolled tillage emissions for cotton, corn, and vegetables, listed in the PEI, by the percent 

county agricultural land in the NAA as follows: 

Example – Uncontrolled Cotton Tillage Emissions – Year 2005: 

Uncontrolled Tillage Emissions = Uncontrolled County Tillage Emissions x % County Ag Land in NAA 

Uncontrolled Tillage EmissionsCotton = 1,140.09 tons/year x 48.005% 

 = 547 tons/year 

Table 11 lists the uncontrolled tillage emissions by crop and percent of the total tillage emissions by 

crop in the NAA for Year 2005. 

Table 11 - Uncontrolled Tillage Emissions in NAA - Year 2005

 

Crop 

Maricopa 

County 

Uncontrolled 

Emissions1 

(tons/year) 

Percent County 

Ag Land 

in NAA1

NAA 

Uncontrolled 

Emissions 

(tons/year) 

NAA 

Uncontrolled Emissions 

(percent) 

Cotton 1,140.09 48.005% 547 68% 

Corn 333.90 160 20% 

Vegetables 201.87 97 12% 

Total 1,675.86 804 100% 

Data Source:

1

MCAQD 2005 Periodic PM10 Emissions Inventory. 

Notes:

MCAQD 2005 Periodic PM10 Emission Inventory lists the following vegetables as having tillage emissions: Dry Onions (23.66 

tons/year), Carrots (73.93 tons/year), and Broccoli (104.28 tons/year). These three crops' tillage emissions were added together 

to produce uncontrolled emissions of 201.87 tons / year for "Vegetables". 

3. Controlled Tillage Emissions in NAA for Year 2005 - Were calculated by multiplying the annual 

uncontrolled tillage emissions for cotton, corn, and vegetables in the NAA (Step #2) by the result of 

1 - Tillage BMP Percent Control Reduction (see Table 3) as follows: 

Example – Controlled Cotton Tillage Emissions – Year 2005: 

Controlled Tillage Emissions = Uncontrolled NAA Tillage Emissions x % BMP Control Reduction 

Controlled Tillage EmissionsCotton = 547 tons/year x (1 – 0.21) 

 = 432 tons/year 

Table 12 lists the controlled tillage emissions by crop in the NAA and percent of total emissions, 

after application of the first and second tillage BMPs from the Tillage & Harvest BMP category, for 

the Year 2005. 
22

Table 12 - Controlled Tillage Emissions in NAA - Year 2005

Controlled Emissions 

(tons/year) 

Crop Uncontrolled 

Emissions1 

(tons/year)

BMP Control 

Reduction2 

(percent) 1st BMP 2nd BMP 

Controlled Emissions 

2nd BMP 

(percent) 

Cotton 547 21% 432 341 68% 

Corn 160 126 100 20% 

Vegetables 97 77 61 12% 

Total 804 635 502 100% 

Data Sources:

1

MCAQD 2005 Periodic PM10 Emissions Inventory. 

2

Table 3 of this report. 

Notes: 

Controlled Emissions from 2nd Tillage BMP = Controlled Emissions from 1st Tillage BMP x (1 - 0.21). 

4. Projected Uncontrolled and Controlled Tillage Emissions in NAA for Years 2008 - 2010 - Were 

calculated by multiplying the Year 2005 totals for uncontrolled and controlled tillage emissions in 

the NAA (Step #3) by the rate of change factors that were developed in Section 1.3.1 of this report 

(see Table 5) as follows: 

Example – Projected Controlled Tillage Emissions – Year 2010: 

Projected Controlled Tillage Emissions = Controlled NAA Tillage Emissions2005 x Rate of Change FactorYear 

Projected Controlled Tillage Emissions2010 = 502 tons/year x 0.790 

 = 397 tons/year 

Table 13 lists the projected uncontrolled and controlled tillage emissions in the NAA for Years 2008 - 

2010. 

Table 13 - Projected Uncontrolled and Controlled Tillage Emissions (2 BMPs) in NAA 

Year 2008 

Rate of Change1

Year 2009 

Rate of Change1

Year 2010 

Rate of Change1

0.868 0.828 0.790 

Year 2008 

Uncontrolled 

Emissions (tons/yr) 

Year 2009 

Uncontrolled 

Emissions (tons/yr) 

Year 2010 

Uncontrolled 

Emissions (tons/yr) 

698 666 635 

Year 2008 

Controlled2 

Emissions (tons/yr) 

Year 2009 

Controlled2 

Emissions (tons/yr) 

Year 2010 

Controlled2 

Emissions (tons/yr) 

436 416 397 

Data Sources: 

1

Table 5 of this report. 

2

Controlled Emissions from application of 1st original tillage BMP (21% emissions reduction) and second 

additional tillage BMP from Tillage & Harvest BMP category (21% emissions reduction applied to controlled 

emissions from 1st tillage BMP). Note: Does not include emission reduction from “Cessation of Night Tillage 

during High Pollution Advisory Days” BMP. 
23

5. Projected Uncontrolled and Controlled Tillage Emissions in MC Portion of Area A for Years 2008 

- 2010 - Were calculated by multiplying the projected uncontrolled and controlled tillage emissions 

in the NAA (Step #4) by the ratio of agricultural land in the MC Portion of Area A to agricultural 

land in the NAA (see Section 1.3.2, Step #5) as follows: 

Example – Projected Controlled Tillage Emissions – Year 2010: 

Projected Controlled Tillage Emissions = Controlled NAA Tillage Emissions x Ratio of Ag Land 

Projected Controlled Tillage Emissions2010 = 397 tons/year x 0.285 

 = 113 tons/year 

Table 14 lists the projected uncontrolled and controlled tillage emissions in the MC Portion of Area A. 

Table 14 - Projected Uncontrolled and Controlled (2 BMPs) Tillage Emissions in MC Portion of Area A 

Year 2008 

Uncontrolled 

Emissions (tons/yr) 

Year 2009 

Uncontrolled 

Emissions (tons/yr) 

Year 2010 

Uncontrolled 

Emissions (tons/yr) 

Ratio of Ag Land: 

MC Portion of Area A / 

Nonattainment Area1

199 190 181 0.285 

Year 2008 

Controlled 

Emissions (tons/yr) 

Year 2009 

Controlled 

Emissions (tons/yr) 

Year 2010 

Controlled 

Emissions (tons/yr) 

124 119 113 

Data Source: 1

Section 1.3.2, Step #5 of this report. 

Notes:

1. "MC Portion of Area A" is the portion of Area A in Maricopa County that is outside of the Maricopa County 

PM10 Nonattainment Area (i.e., does not include portion of Area A that is in Pinal County). 

2.Controlled Emissions are from application of 2 Tillage BMPs from Tillage & Harvest BMP category. It does not 

include emission reduction from "Cessation of Night Tillage during High Pollution Advisory Days" BMP. 

 

6. Projected Uncontrolled and Controlled Tillage Emissions in Area A (Maricopa County) for Years 

2008 - 2010 - Were calculated by adding the uncontrolled and controlled tillage emissions for the 

NAA (step #4) with the uncontrolled and controlled tillage emissions from the MC Portion of Area A 

(step #5) for Years 2008 – 2010 as follows: 

Example – Projected Controlled Tillage Emissions – Year 2010: 

Projected Controlled Tillage Emissions = NAA Controlled Tillage Emissions + MC Portion of Area A 

Controlled Tillage Emissions 

Projected Controlled Tillage Emissions2010 = 397 tons/year + 113 tons/year 

 = 510 tons/year 

Table 15 lists the projected uncontrolled and controlled tillage emissions in Area A (Maricopa 

County) for Years 2008 – 2010. 
24

Table 15 - Projected Uncontrolled and Controlled Tillage (2 BMPs) Emissions in Area A (Maricopa County) 

Year 2008 

Uncontrolled Emissions 

(tons/yr) 

Year 2009 

Uncontrolled Emissions 

(tons/yr) 

Year 2010 

Uncontrolled Emissions 

(tons/yr) 

897 856 816 

Year 2008 

Controlled Emissions 

(tons/yr) 

Year 2009 

Controlled Emissions

(tons/yr) 

Year 2010 

Controlled Emissions

(tons/yr) 

560 535 510 

Notes:

1. "Area A (Maricopa County)" does not include Pinal County portion of Area A. Area A (Maricopa County) is 

comprised of Maricopa County PM10 Nonattainment Area and MC Portion of Area A (portion of Area A in 

Maricopa County that is outside of the nonattainment area). 

2. Controlled Tillage Emissions in Area A (Maricopa County) = Controlled Emissions in NAA (from 1st and 2nd 

Tillage BMPs) + Controlled Emissions in MC Portion of Area A (from 1st and 2nd Tillage BMPs). 

7. Projected Controlled Tillage Emissions in Area A (Maricopa County) by Crop for Years 2008 - 

2010 - Were calculated by multiplying the uncontrolled and controlled tillage emissions in Area A 

(Maricopa County) from Step #6 by the percent tillage emissions by crop (see “Controlled 

Emissions, 2nd BMP” column of Table 12) as follows: 

Example – Projected Controlled Tillage Emissions – Cotton in Year 2010: 

Projected Controlled Tillage EmissionsCrop = Controlled NAA Tillage Emissions x % Tillage EmissionsCrop 

Projected Controlled Tillage EmissionsCotton = 510 tons/year x 68% 

 = 347 tons/year 

Table 16 lists the projected uncontrolled and controlled tillage emissions, by crop, in Area A 

(Maricopa County) for Years 2008 – 2010. 

Table 16 - Projected Controlled Tillage (2 BMPs) Emissions in Area A (Maricopa County) by Crop 

Crop Year 2008 Year 2009 Year 2010 

Emissions1 Emissions1 Emissions1 

(tons/yr) (tons/yr) (tons/yr) 

 

Cotton 381 364 347 

Corn 112 107 102 

Vegetables 67 64 61 

Total 560 535 510 

Notes: 1

Tillage Emissions by Crop = (Tillage Emissions in Area A, Maricopa County) x (Percent Tillage Emissions by 

crop). 
25

8. Emission Reductions from Banning Tilling on HPAs in Area A (Maricopa County) for Years 2008 

– 2010 - Were calculated by multiplying controlled tillage emissions, by crop, in Area A (Maricopa 

County) from Step #7 by the ratio of stagnation days to tillage days (see “Stagnation Days / Tillage 

Days” column of Table 10) as follows: 

Example – Emissions Reduction from Banning Tilling during HPAs – Corn in Year 2010: 

Emissions ReductionCrop = Controlled Tillage EmissionsCrop x Stagnation Days / Tillage DaysCrop 

Emissions ReductionCorn = 102 tons/year x 15% 

 = 15 tons/year 

Table 17 lists the potential emission reductions from banning tilling on HPAs (stagnation days) in 

Area A (Maricopa County) for Years 2008 -2010. 

Table 17 - Potential Emission Reductions from Banning Tilling on HPAs in Area A (Maricopa County 

Crop Year 2008 

Emission Reductions 

(tons/year) 

Year 2009 

Emission Reductions 

(tons/year) 

Year 2010 

Emission Reductions 

(tons/year) 

Cotton 38 36 34 

Corn 17 16 15 

Vegetables 12 12 11 

Total 67 64 60 

Notes:

1. It has been observed that dust can remain suspended in the air for extended periods on a stagnation day. An 

assumption was made that dust resulting from agricultural tilling will remain suspended twice as long on a 

stagnation day as on a "non-stagnation day" and this will have an effect on air quality / emissions which is 

equivalent to an additional agricultural tilling day. Thus, banning tilling on a HPA, that is a stagnation day, was 

assumed to reduce one day's equivalent of agricultural tilling emissions. 

2. Tilling Emission Reductions from Banning Tilling on HPAs = (Controlled Emissions from application of 2 

Tillage BMPS from Tillage & Harvest BMP category) x (Stagnation Days / Potential Tillage Days). 

3. Cotton Emission Reductions: ADEQ's analysis of PM10 exceedance and stagnation days indicated that 

stagnation days do not typically occur in March. Thus, the March tillage emissions for cotton were not included in 

the Ban Tilling on HPAs emissions reduction calculation for cotton. A ratio of 59 days / 90 days, or 0.66, was used 

to adjust the 3-month total of January, February, and March cotton tillage emissions to a 2-month total of January 

and February cotton tillage emissions. Example: Year 2010 cotton tillage emission reductions from Banning 

Tilling on HPAs = 347 tons/year x 15% x 0.66 = 34 tons/year. 
26

9. Emission Reductions from Banning Tilling from 2 AM to 8 AM on HPAs in Area A (Maricopa 

County) for Years 2008 – 2010 - Were calculated by multiplying emission reductions, by crop, in 

Area A (Maricopa County) from Step #8 by the ratio of 6 hours / 24 hours as follows: 

Example – Emissions Reduction from Banning Tilling from 2 AM to 8 AM during HPAs – Cotton - 

Year 2010: 

Emissions ReductionCrop = Emissions ReductionCrop x Ratio of Tilling Ban Hours per Day 

Emissions ReductionCotton = 34 tons/year x 6 hours / 24 hours 

 = 9 tons/year 

Table 18 lists the potential emission reductions from banning tilling from 2 AM to 8 AM on HPAs 

(stagnation days) in Area A (Maricopa County) for Years 2008 – 2010. 

Table 18 - Potential Emission Reductions from Banning Tilling from 2 AM to 8 AM on HPAs

Crop Year 2008 

Emission Reductions 

(tons/year) 

Year 2009 

Emission Reductions 

(tons/year) 

Year 2010 

Emission Reductions 

(tons/year) 

Percent HPA Day 

2 AM to 8 AM 

(6 hours / 24 hours) 

Cotton 10 9 9 25% 

Corn 4 4 4 

Vegetables 3 3 3 

Total 17 16 16 

Notes:

1. It was assumed that agricultural tilling does not vary by hour on an agricultural tilling day (based on 

conversations with growers on Governor's Ag BMP Committee who said that they often have two or three shifts of 

workers operating farm machinery per day. These growers recommended 2 AM to 8 AM ban on tilling on HPAs). 

2. Emission Reductions from Banning Tilling from 2 AM to 8 AM on HPAs = (Emission Reductions on HPAs) x 

Percent HPA Day. 

3. This control measure is referred to as "Cessation of Night Tillage on High Pollution Advisory Days" in 

Agricultural Best Management Practices SIP. 

10. Percent Emission Reduction from Banning Tilling from 2 AM to 8 AM on HPAs in Area A 

(Maricopa County) for Year 2010 - Was calculated by dividing the Year 2010 tillage emission 

reduction for Area A (Maricopa County) from Step #9 by the Year 2010 uncontrolled tillage 

emissions (see Table 15) as follows: 

Example – Percent Emission Reduction from Banning Tilling from 2 AM to 8 AM during HPAs – Year 

2010: 

Percent Emission Reduction = Emissions Reduction / Uncontrolled Tillage Emissions 

= (16 tons/year / 816 tons/year) x 100% 

 = 2.0% 
27

1.3.4 Summary of Agricultural Emission Reductions from Senate Bill 1552 

Table 19 lists the potential emission reductions from implementation of the two agricultural control 

measure packages listed in Senate Bill 1552. 

 

Table 19 - Summary of Potential PM10 Emission Reductions 

 from Agricultural Control Measures in Senate Bill 1552 (tons / year) 

Control Measure Category 2008 2009 2010 

Require One Additional BMP Per Category and Extend Agricultural 

BMP Program to Maricopa County Portion of Area A Outside of the 

PM10 Nonattainment Area: 

 

 Tillage and Harvest BMP 392 374 357 

 Non-Cropland / Unpaved Farm Roads BMP 161 153 147 

 Cropland / Windblown Agriculture BMP 506 484 461 

Total 1,059 1,011 965 

 

Ban Agricultural Tilling from 2 AM to 8 AM on HPAs 

(Cessation of Night Tillage on High Pollution Advisory Days) 17 16 16 

 

Total Agricultural Emission Reductions From Senate Bill 1552 1,076 1,027 981 

Table 20 lists the percent emission reductions by agricultural control measure in Senate Bill 1552. 

Table 20 - Percent Emission Reductions of Agricultural Control Measures in Senate Bill 1552

Agricultural Control Measure

Emission Reduction 

(percent) 

Revised Agricultural BMP Program: 

● Tillage and Harvest BMPs 21.3% 

● Noncropland / Farm Roads BMPs 12.8% 

● Cropland / Windblown Agriculture BMPs 30.1% 

Ban Agricultural Tilling from 2 AM to 8 AM on HPAs1

(Cessation of Night Tillage on High Pollution Advisory Days) 

2.0% 

Notes:

1

Emission Reduction Percent for Year 2010. 
28

1.4 REFERENCES 

ADEQ. 2005. Revised PM10 State Implementation Plan for the Salt River Area, Technical Support 

Document. Air Quality Division, Arizona Department of Environmental Quality. September 2005. 

http://azdeq.gov/environ/air/plan/download/sr-tsd.pdf

ADEQ. 2007a. Comparison Of Potential PM10 Emissions Reductions From Implementation Of Maricopa 

County Agricultural BMPs and San Joaquin Conservation Measure Practices. Air Quality Division, 

Arizona Department of Environmental Quality. January 22, 2007. 

http://www.azda.gov/ACT/Emissions%20Comparison%20Report.pdf

ADEQ. 2007b. 2005-2006 Forecast Season PM10 Exceedance Report for Maricopa County. Air Quality 

Division, Arizona Department of Environmental Quality. January 2007. 

Governor’s Agricultural BMP Committee. 2001. Guide to Agricultural PM10 Best Management Practices, 

Maricopa County PM10 Nonattainment Area. http://www.azda.gov/ACT/bmpguide.pdf

MAG. 2004. MAG 2004 Existing Land Use Data. Maricopa Association of Governments. 

MAG. 2007. MAG 2007 Five Percent Plan for PM-10 for the Maricopa County Nonattainment Area; 

Appendices Volume 3 and 4; Technical Document in Support of the MAG 2007 Five Percent Plan 

for PM-10 for the Maricopa County Nonattainment Area. Maricopa Association of Governments. 

December 2007. http://magwww.mag.maricopa.gov/detail.cms?item=8072 

MCAQD. 2007. 2005 Periodic Emissions Inventory for PM10 for the Maricopa County, Arizona, 

Nonattainment Area. Maricopa County Air Quality Department. May 2007. 

http://www.maricopa.gov/aq/divisions/planning_analysis/emissions_inventory/reports/Default.aspx

San Joaquin Valley APCD. 2006. Conservation Management Practices Program Report for 2005. San 

Joaquin Valley Air Pollution Control District. January 19, 2006. 

http://www.valleyair.org/farmpermits/updates/cmp_program_report_for_2005.pdf

URS. 2001. Technical Support Document for Quantification of Agricultural Best Management Practices, 

Revised Final Draft. ADEQ Contract No. 98-0159-BF. URS Corporation and Eastern Research 

Group, Inc. June 8, 2001. http://www.azda.gov/ACT/AgBMP_SIP_TSD-URSrpt6-01.pdf

USDA. 2002. The Census of Agriculture – Year 2002. United States Department of Agriculture, National 

Agricultural Statistics Service. 

http://www.agcensus.usda.gov/Publications/2002/Census_by_State/Arizona/index.asp

USDA. 2005. Arizona Agricultural Statistics – Year 2004. United States Department of Agriculture, 

National Agricultural Statistics Service. September 2005. 

http://www.nass.usda.gov/Statistics_by_State/Arizona/index.asp
Attachment - 1 

ATTACHMENT #1 

Table A-1 provides detailed data on the individual control measures, specific crops affected by the control measures, emi

emissions, control efficiencies, and potential emissions reductions from the Maricopa County BMPs and San Joaquin CM

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

CL CROPLAND – LAND 

PREPARATION / 

CULTIVATION 

CL2 Bed/Row Size or Spacing: (EF - Land Prep) 

 Citrus 4,464 0.07 312 0% 9% 0  Corn 6,241 6.90 43,063 0% 12% 0  Cotton 9,841 8.90 87,585 0% 9% 0  Onions 336 6.50 2,184 0% 12% 0  Wheat 18,200 4.45 80,990 0% 16% 0  Barley 7,537 4.45 33,540 0% 16% 0  Lettuce 96 12.75 1,224 0% 6% 0  Melons 6,529 5.70 37,215 0% 2% 0 

Vegetables 2,352 9.05 21,286 0% 1% 0 

CL3 Chemigation /Fertigation: (EF - Land Prep) No data at this time 

 Alfalfa 36,004 4.00 144,016 0% 2% 0  Citrus 4,464 0.07 312 0% 9% 0  Corn 6,241 6.90 43,063 0% 1% 0  Cotton 9,841 8.90 87,585 0% 9% 0  Onions 336 6.50 2,184 0% 6% 0 
Attachment-2

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

 Wheat 8,737 4.45 38,880 0% 8% 0  Barley 7,537 4.45 33,540 0% 8% 0  Lettuce 96 12.75 1,224 0% 3% 0  Melons 6,529 5.70 37,215 0% 1% 0 

CL4 Combined Operations: 18,621 

 Combining land 

preparation operations 

 (EF - Land 

Prep) 

 Cotton 9,841 8.9 87,585 8% 0% 7007  Wheat 8,737 4.45 38,880 8% 0% 3110  Barley 7,537 4.45 33,540 8% 0% 2683  Corn 6,241 6.9 43,063 8% 0% 3445  Vegetables 2,352 9.05 21,286 11% 0% 2341  Citrus 4,464 0.07 312 11% 0% 34 

CL5 Conservation Irrigation: (EF - Land Prep) 

 Alfalfa 36,004 4.00 144,016 0% 6% 0  Citrus 4,464 0.07 312 0% 9% 0  Corn 6,241 6.90 43,063 0% 12% 0  Cotton 9,841 8.90 87,585 0% 9% 0  Onions 336 6.50 2,184 0% 12% 0  Wheat 8,737 4.45 38,880 0% 16% 0  Barley 7,537 4.45 33,540 0% 16% 0  Lettuce 96 12.75 1,224 0% 6% 0  Melons 6,529 5.70 37,215 0% 2% 0  Vegetables 2,352 9.05 21,286 0% 1% 0 
Attachment-3

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

CL6 Conservation Tillage: (EF - Land Prep) (25% - 100% 

Reduced 

Tillage) 

166,935 

 Corn 6,241 6.90 43,063 63% 35% 27,130  Cotton 9,841 8.90 87,585 63% 28% 55178  Onions 336 6.50 2,184 63% 4% 1376  Wheat 8,737 4.45 38,880 63% 16% 24494  Barley 7,537 4.45 33,540 63% 16% 21130  Lettuce 96 12.75 1,224 63% 5% 771  Melons 6,529 5.70 37,215 63% 4% 23446  Vegetables 2,352 9.05 21,286 63% 35% 13410 

CL7 Cover Crops: (EF - Land Prep) 134 

 Citrus 4,464 0.07 312 43% 27% 134 

CL8 Equipment Changes/Technological 

Improvements: 

 (EF - Land 

Prep) 

 50% 50% 132,644 

Citrus 4,464 0.07 312 50% 50% 156 Corn 6,241 6.90 43,063 50% 50% 21531 Cotton 9,841 8.90 87,585 50% 50% 43792 Onions 336 6.50 2,184 50% 50% 1092 Wheat 8,737 4.45 38,880 50% 50% 19440 Barley 7,537 4.45 33,540 50% 50% 16770 Lettuce 96 12.75 1,224 50% 50% 612 Melons 6,529 5.70 37,215 50% 50% 18608 Vegetables 2,352 9.05 21,286 50% 50% 10643 
Attachment-4

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

CL11 Integrated Pest Management: (EF - Land Prep) 

 Corn 6,241 6.90 43,063 0% 12% 0  Cotton 9,841 8.90 87,585 0% 19% 0 

CL12 Limited Activity During a High-Wind 

Event:

 (EF - Land 

Prep) 

49,887 

 Cotton 9,841 8.9 87,585 9% 0% 7883  Wheat 8,737 4.45 38,880 9% 0% 3499  barley 7,537 4.45 33,540 9% 0% 3019  Corn 6,241 6.9 43,063 9% 0% 3876  Alfalfa 36,004 4 144,016 20% 0% 28803  Vegetables 2,352 9.05 21,286 13% 0% 2767  Citrus 4,464 0.07 312 13% 0% 41 

CL13 Mulching: (EF - Land Prep) 

 Corn 6,241 6.9 43,063 0% 12% 0  Onions 336 6.5 2,184 0% 18% 0  Wheat 8,737 4.45 38,880 0% 0.80% 0  Barley 7,537 4.45 33,540 0% 8% 0  Lettuce 96 12.75 1,224 0% 9% 0  Melons 6,529 5.7 37,215 0% 21% 0  Vegetables 2,352 9.05 21,286 0% 35% 0 

CL14 Multi-Year Crop: (EF - Land Prep) 32,491 
Attachment-5

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

 Cotton 9,841 8.9 87,585 16% 0% 14014  Wheat 8,737 4.45 38,880 16% 0% 6221  Barley 7,537 4.45 33,540 16% 0% 5366  Corn 6,241 6.9 43,063 16% 0% 6890 

CL15 Night Farming: (EF - Land Prep) 

Citrus 4,464 0.07 312 0% 10% 0 Corn 6,241 6.90 43,063 0% 10% 0 Cotton 9,841 8.90 87,585 0% 10% 0 Onions 336 6.50 2,184 0% 10% 0 Wheat 8,737 4.45 38,880 0% 10% 0 Barley 7,537 4.45 33,540 0% 10% 0 Lettuce 96 12.75 1,224 0% 10% 0 Melons 6,529 5.70 37,215 0% 10% 0 Vegetables 2,352 9.05 21,286 0% 10% 0 

CL16 Non-Tillage/Chemical Tillage: (EF - Land Prep) 

 Alfalfa 36,004 4 144,016 0% 8% 0  Citrus 4,464 0.07 312 0% 30% 0 

CL17 Organic Practices: (EF - Land Prep) 

 Alfalfa 36,004 4.00 144,016 0% 9% 0  Citrus 4,464 0.07 312 0% 14% 0  Corn 6,241 6.90 43,063 0% 17% 0  Cotton 9,841 8.90 87,585 0% 18% 0 
Attachment-6

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

 Onions 336 6.50 2,184 0% 18% 0  Wheat 8,737 4.45 38,880 0% 16% 0  Barley 7,537 4.45 33,540 0% 16% 0  Lettuce 96 12.75 1,224 0% 5% 0  Melons 6,529 5.70 37,215 0% 21% 0  Vegetables 2,352 9.05 21,286 0% 35% 0 

CL18 Planting Based on Soil Moisture: (EF - Land Prep) 30% 19 

 Citrus 4,464 0.07 312 6% 0% 19  Corn 6,241 6.90 43,063 0% 0% 0  Cotton 9,841 8.90 87,585 0% 0% 0  Onions 336 6.50 2,184 0% 0% 0  Wheat 8,737 4.45 38,880 0% 0% 0  Barley 7,537 4.45 33,540 0% 0% 0  Lettuce 96 12.75 1,224 0% 0% 0  Melons 6,529 5.70 37,215 0% 0% 0  Vegetables 2,352 9.05 21,286 0% 0% 0 

CL19 Precision Farming: (EF - Land Prep) 

 Citrus 4,464 0.07 312 0% 15% 0  Corn 6,241 6.90 43,063 0% 15% 0  Cotton 9,841 8.90 87,585 0% 15% 0  Onions 336 6.50 2,184 0% 15% 0  Wheat 8,737 4.45 38,880 0% 15% 0  Barley 7,537 4.45 33,540 0% 15% 0  Lettuce 96 12.75 1,224 0% 15% 0  Melons 6,529 5.70 37,215 0% 15% 0  Vegetables 2,352 9.05 21,286 0% 15% 0 
Attachment-7

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

CL20 Tillage Based on Soil Moisture: (EF - Land Prep) 

 Citrus 4,464 0.07 312 0% 15% 0  Corn 6,241 6.90 43,063 0% 15% 0  Cotton 9,841 8.90 87,585 0% 15% 0  Onions 336 6.50 2,184 0% 15% 0  Wheat 8,737 4.45 38,880 0% 15% 0  Barley 7,537 4.45 33,540 0% 15% 0  Lettuce 96 12.75 1,224 0% 15% 0  Melons 6,529 5.70 37,215 0% 15% 0  Vegetables 2,352 9.05 21,286 0% 15% 0 

CL21 Time of Planting: (EF - Land Prep) (50 % - 60% 

Timing of 

Tillage 

Operation) 

No data at 

this time 

145,737 

Corn 6,241 6.90 43,063 55% 0% 23685 Cotton 9,841 8.90 87,585 55% 0% 48172 Onions 336 6.50 2,184 55% 0% 1201 Wheat 8,737 4.45 38,880 55% 0% 21384 Barley 7,537 4.45 33,540 55% 0% 18447 Lettuce 96 12.75 1,224 55% 0% 673 Melons 6,529 5.70 37,215 55% 0% 20468 Vegetables 2,352 9.05 21,286 55% 0% 11707 

CL22 Timing of Tillage Operation: (EF - Land Prep) 23,928 

 Cotton 9,841 8.9 87,585 10% 0% 8758 
Attachment-8

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

 Wheat 8,737 4.45 38,880 15% 0% 5832  Barley 7,537 4.45 33,540 15% 0% 5031  Corn 6,241 6.9 43,063 10% 0% 4306 

CL23 Transgenic Crops: (EF – Land Prep) 

 Alfalfa 36,004 4 144,016 0% 2% 0  Corn 6,241 6.90 43,063 0% 12% 0  Cotton 9,841 8.90 87,585 0% 9% 0  Onions 336 6.50 2,184 0% 12% 0  Wheat 8,737 4.45 38,880 0% 4% 0  Barley 7,537 4.45 33,540 0% 4% 0  Lettuce 96 12.75 1,224 0% 6% 0  Melons 6,529 5.70 37,215 0% 2% 0  Vegetables 2,352 9.05 21,286 0% 9% 0 

CL24 Transplanting: (EF – Land Prep) 

 Onions 336 6.5 2,184 0% 12% 0  Lettuce 96 12.75 1,224 0% 6% 0  Melons 6,529 5.7 37,215 0% 2% 0  Vegetables 2,352 9.05 21,286 0% 9% 0 

CH CROPLAND – 

HARVEST 

CH1 Baling/Large Balers: (EF - Harvest) 
Attachment-9

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

 Alfalfa 36,004 0.24 8,641 0% 11% 0  Wheat 8,737 3.45 30,143 0% 25% 0  Barley 7,537 3.45 26,003 0% 25% 0 

CH2 Combined Operations: (EF - Harvest) 26,036 

 Cotton 9,841 3.37 33,164 17% 0% 5638  Wheat 8,737 3.45 30,143 34% 0% 10249  Barley 7,537 3.45 26,003 34% 0% 8841  Corn 6,241 0.43 2,684 34% 0% 912  Vegetables 2,352 0.23 541 34% 0% 184  Citrus 4,464 0.14 625 34% 0% 212 

CH4 Equipment Changes/Technological 

Improvements:

(EF - 

Harvest) 

51,674 

 Alfalfa 36,004 0.24 8,641 50% 50% 4320  Citrus 4,464 0.14 625 50% 50% 312  Corn 6,241 0.43 2,684 50% 50% 1342  Cotton 9,841 3.37 33,164 50% 50% 16582  Onions 336 1.68 564 50% 50% 282  Wheat 8,737 3.45 30,143 50% 50% 15071  Barley 7,537 3.45 26,003 50% 50% 13001  Lettuce 96 0.23 22 50% 50% 11  Melons 6,529 0.23 1,502 50% 50% 751 

CH7 Green Chop: (EF - Harvest) 

 Alfalfa 36,004 0.24 8,641 0% 10% 0  Corn Grain and Silage 13,000 0.43 5,590 0% 17% 0 
Attachment-10

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

 Dry Beans, Cereal 

Grains, Safflower, Wheat, and Barley 

33,900 3.45 116,955 0% 20% 0 

CH8 Hand Harvesting: (EF - Harvest) 

 Citrus 4,464 0.14 625 0% 33% 0  Corn 6,241 0.43 2,684 0% 33% 0  Onions 336 1.68 564 0% 33% 0  Lettuce 96 0.23 22 0% 33% 0  Melons 6,529 0.23 1,502 0% 33% 0  Vegetables 2,352 0.23 541 0% 33% 0 

CH9 Night Harvesting: (EF - Harvest) 

 Alfalfa 36,004 0.24 8,641 0% 10% 0  Citrus 4,464 0.14 625 0% 10% 0  Corn 6,241 0.43 2,684 0% 10% 0  Cotton 9,841 3.37 33,164 0% 10% 0  Onions 336 1.68 564 0% 10% 0  Wheat 8,737 3.45 30,143 0% 10% 0  Barley 7,537 3.45 26,003 0% 10% 0  Lettuce 96 0.23 22 0% 10% 0  Melons 6,529 0.23 1,502 0% 10% 0 

CH11 Pre-Harvest Soil Preparation: (EF - Harvest) 

 Alfalfa 36,004 0.24 8,641 0% 7% 0  Citrus 4,464 0.14 625 0% 10% 0  Corn 6,241 0.43 2,684 0% 5% 0 
Attachment-11

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

 Cotton 9,841 3.37 33,164 0% 12% 0  Onions 336 1.68 564 0% 10% 0  Wheat 8,737 3.45 30,143 0% 0% 0  Barley 7,537 3.45 26,003 0% 0% 0  Lettuce 96 0.23 22 0% 0% 0  Melons 6,529 0.23 1,502 0% 0% 0  Vegetables 2,352 0.23 541 0% 15% 0 

CH12 Reduced Harvest Activity: (EF - Harvest) 10,089 

 Cotton 9,841 3.37 33,164 20% 0% 6633  Alfalfa 36,004 0.24 8,641 40% 0% 3456 

CH13 Shed Packing: (EF - Harvest) 

 Onions 336 1.68 564 0% 12% 0  Lettuce 96 0.23 22 0% 7% 0  Melons 6,529 0.23 1,502 0% 10% 0  Vegetables 2,352 0.23 541 0% 10% 0 

CH14 Shuttle System / Larger Carrier: (EF - Harvest) 

 Alfalfa 36,004 0.24 8,641 0% 17% 0  Citrus 4,464 0.14 625 0% 17% 0  Corn 6,241 0.43 2,684 0% 17% 0  Cotton 9,841 3.37 33,164 0% 40% 0  Onions 336 1.68 564 0% 17% 0  Wheat 8,737 3.45 30,143 0% 17% 0  Barley 7,537 3.45 26,003 0% 17% 0  Lettuce 96 0.23 22 0% 17% 0 
Attachment-12

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

 Melons 6,529 0.23 1,502 0% 17% 0  Vegetables 2,352 0.23 541 0% 17% 0 

CO CROPLAND 

ACTIVITIES - 

OTHER 

CO1 Alternate Tilling: (EF - Land Prep) 

Alfalfa 36,004 4 144,016 0% 32.50% 0 

 Corn 6,241 6.90 43,063 0% 32.50% 0  Cotton 9,841 8.90 87,585 0% 32.50% 0  Onions 336 6.50 2,184 0% 32.50% 0  Wheat 8,737 4.45 38,880 0% 32.50% 0  Barley 7,537 4.45 33,540 0% 32.50% 0  Lettuce 96 12.75 1,224 0% 32.50% 0  Melons 6,529 5.70 37,215 0% 32.50% 0  Vegetables 2,352 9.05 21,286 0% 32.50% 0 

CO2 Application Efficiencies: (EF - Land Prep) 

Alfalfa 36,004 4 144,016 0% 8% 0 Corn 6,241 6.90 43,063 0% 12% 0 Cotton 9,841 8.90 87,585 0% 9% 0 Onions 336 6.50 2,184 0% 12% 0 Wheat 8,737 4.45 38,880 0% 16% 0 Barley 7,537 4.45 33,540 0% 16% 0 Lettuce 96 12.75 1,224 0% 6% 0 Melons 6,529 5.70 37,215 0% 2% 0 Vegetables 2,352 9.05 21,286 0% 1% 0 
Attachment-13

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

CO3 Baling/Large Balers: (EF - Harvest) 

Alfalfa 36,004 0.24 8,641 0% 11% 0 

 Wheat 8,737 3.45 30,143 0% 25% 0  Barley 7,537 3.45 26,003 0% 25% 0 

CO5 Chemigation /Fertigation: (EF - Land Prep) 

Alfalfa 36,004 4.00 144,016 0% 2% 0 Citrus 4,464 0.07 312 0% 9% 0 Corn 6,241 6.90 43,063 0% 1% 0 Cotton 9,841 8.90 87,585 0% 9% 0 Onions 336 6.50 2,184 0% 6% 0 Wheat 8,737 4.45 38,880 0% 8% 0 Barley 7,537 4.45 33,540 0% 8% 0 Lettuce 96 12.75 1,224 0% 3% 0 Melons 6,529 5.70 37,215 0% 1% 0 Vegetables 2,352 9.05 21,286 0% 0% 0 

CO6 Conservation Irrigation: (EF - Land Prep) 

Alfalfa 36,004 4.00 144,016 0% 6% 0 Citrus 4,464 0.07 312 0% 9% 0 Corn 6,241 6.90 43,063 0% 12% 0 Cotton 9,841 8.90 87,585 0% 9% 0 Onions 336 6.50 2,184 0% 12% 0 Wheat 8,737 4.45 38,880 0% 16% 0 Barley 7,537 4.45 33,540 0% 16% 0 Lettuce 96 12.75 1,224 0% 6% 0 Melons 6,529 5.70 37,215 0% 2% 0 Vegetables 2,352 9.05 21,286 0% 1% 0 
Attachment-14

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

CO7 Cover Crops: (EF - Land Prep) (20% - 66%) 

Citrus 4,464 0.07 312 43% 27% 134 

CO8 Cross-Wind Ridges (reduces wind erosion 

on cropland): 

 (EF - Wind 

Erosion 

Cropland) 

 20% - 93% 2,067,022 

Citrus 4,464 122.24 545,679 57% 0% 311037 Corn 6,241 108.05 674,340 57% 0% 384374 Cotton 9,841 128.84 1,267,914 57% 0% 722711 Onions 336 122.24 41,073 57% 0% 23411 Wheat 8,737 0 0 57% 0% 0 Barley 7,537 0 0 57% 0% 0 Lettuce 96 122.24 11,735 57% 0% 6689 Melons 6,529 122.24 798,105 57% 0% 454920 Vegetables 2,352 122.24 287,508 57% 0% 163880 

CO11 Grinding / Chipping / Shredding: (EF - Land Prep) 

 Citrus 4,464 0.07 312 0% 90% 0  Cotton 9,841 8.9 87,585 0% 90% 0  Alfalfa (under soil 

incorporation) 

36,004 4 144,016 0% 97% 0 

 Corn (under soil 

incorporation) 

6,241 6.9 43,063 0% 97% 0 

CO12 Integrated Pest Management: (EF - Land Prep) 

Alfalfa 36,004 4.00 144,016 0% 8% 0 Citrus 4,464 0.07 312 0% 9% 0 Corn 6,241 6.90 43,063 0% 12% 0 
Attachment-15

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

Cotton 9,841 8.90 87,585 0% 9% 0 Onions 336 6.50 2,184 0% 12% 0 Wheat 8,737 4.45 38,880 0% 16% 0 Barley 7,537 4.45 33,540 0% 16% 0 Lettuce 96 12.75 1,224 0% 6% 0 Melons 6,529 5.70 37,215 0% 2% 0 Vegetables 2,352 9.05 21,286 0% 1% 0 

CO15 Mulching: (EF - Land Prep) (50% - 55%) 94,017 

Corn 6,241 6.9 43,063 53% 32.50% 22823 Onions 336 6.5 2,184 53% 32.50% 1158 Wheat 8,737 4.45 38,880 53% 32.50% 20606 Barley 7,537 4.45 33,540 53% 32.50% 17776 Lettuce 96 12.75 1,224 53% 32.50% 649 Melons 6,529 5.7 37,215 53% 32.50% 19724 Vegetables 2,352 9.05 21,286 53% 32.50% 11281 

CO16 Multi-Year Crop: (EF - Land Prep) 48,736 

 Cotton 9,841 8.9 87,585 24% 0% 21020  Wheat 8,737 4.45 38,880 24% 0% 9331  Barley 7,537 4.45 33,540 24% 0% 8050  Corn 6,241 6.9 43,063 24% 0% 10335 

CO17 Night Farming / Night Harvesting: (EF - Harvest) 

 Alfalfa 36,004 0.24 8,641 0% 5% 0  Citrus 4,464 0.14 625 0% 5% 0  Corn 6,241 0.43 2,684 0% 5% 0 
Attachment-16

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

 Cotton 9,841 3.37 33,164 0% 5% 0  Onions 336 1.68 564 0% 5% 0  Wheat 8,737 3.45 30,143 0% 5% 0  Barley 7,537 3.45 26,003 0% 5% 0  Lettuce 96 0.23 22 0% 5% 0  Melons 6,529 0.23 1,502 0% 5% 0  Vegetables 2,352 0.23 541 0% 5% 0 

CO19 Non-Tillage/Chemical Tillage: (EF - Land Prep) 

 Alfalfa 36,004 4 144,016 0% 8% 0  Citrus 4,464 0.07 312 0% 30% 0 

CO20 Organic Practices: (EF - Land Prep) 

 Alfalfa 36,004 4.00 144,016 0% 9% 0  Citrus 4,464 0.07 312 0% 14% 0  Corn 6,241 6.90 43,063 0% 17% 0  Cotton 9,841 8.90 87,585 0% 18% 0  Onions 336 6.50 2,184 0% 18% 0  Wheat 8,737 4.45 38,880 0% 16% 0  Barley 7,537 4.45 33,540 0% 16% 0  Lettuce 96 12.75 1,224 0% 5% 0  Melons 6,529 5.70 37,215 0% 21% 0  Vegetables 2,352 9.05 21,286 0% 35% 0 

CO22 Reduced Pruning: (EF - Land Prep) 

 Citrus 4,464 0.07 312 0% 9% 0 
Attachment-17

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

CO23 Residue Management: (EF - Harvest) 14,408 

 Cotton 9,841 3.37 33,164 12% 0% 3980  Wheat 8,737 3.45 30,143 18% 0% 5426  Barley 7,537 3.45 26,003 18% 0% 4680  Corn 6,241 0.43 2,684 12% 0% 322 

CO24 Sequential Cropping: (EF - Land Prep) 204,652 

Alfalfa 36,004 4.00 144,016 50% 0% 72008 Citrus 4,464 0.07 312 50% 0% 156 Corn 6,241 6.90 43,063 50% 0% 21531 Cotton 9,841 8.90 87,585 50% 0% 43792 Onions 336 6.50 2,184 50% 0% 1092 Wheat 8,737 4.45 38,880 50% 0% 19440 Barley 7,537 4.45 33,540 50% 0% 16770 Lettuce 96 12.75 1,224 50% 0% 612 Melons 6,529 5.70 37,215 50% 0% 18608 Vegetables 2,352 9.05 21,286 50% 0% 10643 

CO25 Soil Amendments: (EF - Land Prep) 

Alfalfa 36,004 4.00 144,016 0% 20% 0 Citrus 4,464 0.07 312 0% 20% 0 Corn 6,241 6.90 43,063 0% 20% 0 Cotton 9,841 8.90 87,585 0% 20% 0 Onions 336 6.50 2,184 0% 20% 0 Wheat 8,737 4.45 38,880 0% 20% 0 Barley 7,537 4.45 33,540 0% 20% 0 Lettuce 96 12.75 1,224 0% 20% 0 
Attachment-18

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

Melons 6,529 5.70 37,215 0% 20% 0 Vegetables 2,352 9.05 21,286 0% 20% 0 

CO26 Soil Incorporation: (EF - Land Prep) 

 Citrus 4,464 0.07 312 0% 90% 0  Cotton 9,841 8.9 87,585 0% 90% 0  Alfalfa (under soil 

incorporation) 

36,004 4 144,016 0% 97% 0 

 Corn (under soil 

incorporation) 

6,241 6.9 43,063 0% 97% 0 

CO28 Surface Roughening (reduces wind erosion 

of cropland): 

 (EF - Wind 

Erosion 

Cropland) 

 (15% - 

75%) 

1,631,860 

Alfalfa 36,004 0 0 45% 64% 0 Citrus 4,464 122.24 545,679 45% 64% 245556 Corn 6,241 108.05 674,340 45% 64% 303453 Cotton 9,841 128.84 1,267,914 45% 64% 570561 Onions 336 122.24 41,073 45% 64% 18483 Wheat 8,737 0 0 45% 64% 0 Barley 7,537 0 0 45% 64% 0 Lettuce 96 122.24 11,735 45% 64% 5281 Melons 6,529 122.24 798,105 45% 64% 359147 Vegetables 2,352 122.24 287,508 45% 64% 129379 

CO29 Transgenic Crops: (EF - Land Prep) 

 Alfalfa 36,004 4 144,016 0% 8% 0  Corn 6,241 6.9 43,063 0% 12% 0  Cotton 9,841 8.9 87,585 0% 9% 0 
Attachment-19

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

 Wheat 8,737 4.45 38,880 0% 16% 0  Barley 7,537 4.45 33,540 0% 16% 0 

CO30a Wind Barrier - Artificial (reduces 

wind erosion of cropland):

 (EF - Wind 

Erosion 

Cropland) 

 (0% - 90% 

Artificial 

Wind 

Barrier) 

30% 1,631,860 

Alfalfa 36,004 0 0 45% 30% 0 Citrus 4,464 122.24 545,679 45% 30% 245556 Corn 6,241 108.05 674,340 45% 30% 303453 Cotton 9,841 128.84 1,267,914 45% 30% 570561 Onions 336 122.24 41,073 45% 30% 18483 Wheat 8,737 0 0 45% 30% 0 Barley 7,537 0 0 45% 30% 0 Lettuce 96 122.24 11,735 45% 30% 5281 Melons 6,529 122.24 798,105 45% 30% 359147 Vegetables 2,352 122.24 287,508 45% 30% 129379 

CO30b Wind Barrier - Natural (reduces wind 

erosion of cropland):

 (EF - Wind 

Erosion 

Cropland) 

 (Tree, 

Shrub, or 

Windbreak 

Planting) 

25% 

906,589 

Alfalfa 36,004 0 0 25% 30% 0 Citrus 4,464 122.24 545,679 25% 30% 136420 Corn 6,241 108.05 674,340 25% 30% 168585 Cotton 9,841 128.84 1,267,914 25% 30% 316979 Onions 336 122.24 41,073 25% 30% 10268 Wheat 8,737 0 0 25% 30% 0 Barley 7,537 0 0 25% 30% 0 Lettuce 96 122.24 11,735 25% 30% 2934 
Attachment-20

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

Melons 6,529 122.24 798,105 25% 30% 199526 Vegetables 2,352 122.24 287,508 25% 30% 71877 

CU CROPLAND – 

UNPAVED ROADS 

and UNPAVED 

VEHICLE 

EQUIPMENT AREA 

CU1 Dust Suppressants: CU1a Chips/mulch: (EF - Vehicle 

Traffic) 

 Alfalfa 36,004 0.8 28,803 0% 33% 0  Citrus 4,464 2.46 10,981 0% 33% 0  Corn 6,241 0.8 4,993 0% 33% 0  Cotton 9,841 0.8 7,873 0% 33% 0  Onions 336 4.8 1,613 0% 33% 0  Wheat 8,737 2.8 24,464 0% 33% 0  Barley 7,537 2.8 21,104 0% 33% 0  Lettuce 96 4.8 461 0% 33% 0  Melons 6,529 4.8 31,339 0% 33% 0  Vegetables 2,352 4.8 11,290 0% 33% 0 

CU1b Organic materials/vegetation: (EF - Vehicle 

Traffic) 

 0 

 Alfalfa 36,004 0.8 28,803 0% 33% 0  Citrus 4,464 2.46 10,981 0% 33% 0  Corn 6,241 0.8 4,993 0% 33% 0  Cotton 9,841 0.8 7,873 0% 33% 0 
Attachment-21

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

 Onions 336 4.8 1,613 0% 33% 0  Wheat 8,737 2.8 24,464 0% 33% 0  Barley 7,537 2.8 21,104 0% 33% 0  Lettuce 96 4.8 461 0% 33% 0  Melons 6,529 4.8 31,339 0% 33% 0  Vegetables 2,352 4.8 11,290 0% 33% 0 

CU1c Polymers: (EF - Vehicle 

Traffic) 

 (47% - 

99%) 

104,331 

 Alfalfa 36,004 0.8 28,803 73% 80% 21,026  Citrus 4,464 2.46 10,981 73% 80% 8,016  Corn 6,241 0.8 4,993 73% 80% 3,645  Cotton 9,841 0.8 7,873 73% 80% 5,747  Onions 336 4.8 1,613 73% 80% 1,177  Wheat 8,737 2.8 24,464 73% 80% 17,858  Barley 7,537 2.8 21,104 73% 80% 15,406  Lettuce 96 4.8 461 73% 80% 336  Melons 6,529 4.8 31,339 73% 80% 22,878  Vegetables 2,352 4.8 11,290 73% 80% 8,241 

CU1d Road Oil: (EF - Vehicle 

Traffic) 

 Alfalfa 36,004 0.8 28,803 0% 76% 0  Citrus 4,464 2.46 10,981 0% 76% 0  Corn 6,241 0.8 4,993 0% 76% 0  Cotton 9,841 0.8 7,873 0% 76% 0  Onions 336 4.8 1,613 0% 76% 0 
Attachment-22

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

 Wheat 8,737 2.8 24,464 0% 76% 0  Barley 7,537 2.8 21,104 0% 76% 0  Lettuce 96 4.8 461 0% 76% 0  Melons 6,529 4.8 31,339 0% 76% 0  Vegetables 2,352 4.8 11,290 0% 76% 0 

CU1e Sand: (EF - Vehicle 

Traffic) 

 33% 

 Alfalfa 36,004 0.8 28,803 0% 33% 0  Citrus 4,464 2.46 10,981 0% 33% 0  Corn 6,241 0.8 4,993 0% 33% 0  Cotton 9,841 0.8 7,873 0% 33% 0  Onions 336 4.8 1,613 0% 33% 0  Wheat 8,737 2.8 24,464 0% 33% 0  Barley 7,537 2.8 21,104 0% 33% 0  Lettuce 96 4.8 461 0% 33% 0  Melons 6,529 4.8 31,339 0% 33% 0  Vegetables 2,352 4.8 11,290 0% 33% 0 

CU1f Gravel: (EF - Vehicle 

Traffic) 

 Alfalfa 36,004 0.8 28,803 0% 46% 0  Citrus 4,464 2.46 10,981 0% 46% 0  Corn 6,241 0.8 4,993 0% 46% 0  Cotton 9,841 0.8 7,873 0% 46% 0  Onions 336 4.8 1,613 0% 46% 0  Wheat 8,737 2.8 24,464 0% 46% 0 
Attachment-23

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

 Barley 7,537 2.8 21,104 0% 46% 0  Lettuce 96 4.8 461 0% 46% 0  Melons 6,529 4.8 31,339 0% 46% 0  Vegetables 2,352 4.8 11,290 0% 46% 0 

CU3 Paving: (EF - Vehicle 

Traffic) 

 0 

 Alfalfa 36,004 0.8 28,803 0% 98% 0  Citrus 4,464 2.46 10,981 0% 98% 0  Corn 6,241 0.8 4,993 0% 98% 0  Cotton 9,841 0.8 7,873 0% 98% 0  Onions 336 4.8 1,613 0% 98% 0  Wheat 8,737 2.8 24,464 0% 98% 0  Barley 7,537 2.8 21,104 0% 98% 0  Lettuce 96 4.8 461 0% 98% 0  Melons 6,529 4.8 31,339 0% 98% 0  Vegetables 2,352 4.8 11,290 0% 98% 0 

CU4 Restricted Access: (EF - Vehicle 

Traffic) 

2,858 

 Alfalfa 36,004 0.8 28,803 2% 10% 576  Citrus 4,464 2.46 10,981 2% 10% 220  Corn 6,241 0.8 4,993 2% 10% 100  Cotton 9,841 0.8 7,873 2% 10% 157  Onions 336 4.8 1,613 2% 10% 32  Wheat 8,737 2.8 24,464 2% 10% 489  Barley 7,537 2.8 21,104 2% 10% 422 
Attachment-24

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

 Lettuce 96 4.8 461 2% 10% 9  Melons 6,529 4.8 31,339 2% 10% 627  Vegetables 2,352 4.8 11,290 2% 10% 226 

CU5 Speed Limits: CU5a Reducing speed from 25. 9 mph to 5 mph: (EF - Vehicle 

Traffic) 

60,026 

 Alfalfa 36,004 0.8 28,803 -- 81% 12,097  Citrus 4,464 2.46 10,981 -- 81% 4,612  Corn 6,241 0.8 4,993 -- 81% 2,097  Cotton 9,841 0.8 7,873 -- 81% 3,307  Onions 336 4.8 1,613 -- 81% 677  Wheat 8,737 2.8 24,464 -- 81% 10,275  Barley 7,537 2.8 21,104 -- 81% 8,864  Lettuce 96 4.8 461 -- 81% 194  Melons 6,529 4.8 31,339 -- 81% 13,162  Vegetables 2,352 4.8 11,290 -- 81% 4,742 

CU5b Reducing speed from 25.9 mph to 10 mph: (EF - Vehicle 

Traffic) 

 58% 60,026 

 Alfalfa 36,004 0.8 28,803 -- 58% 12,097  Citrus 4,464 2.46 10,981 -- 58% 4,612  Corn 6,241 0.8 4,993 -- 58% 2,097  Cotton 9,841 0.8 7,873 -- 58% 3,307  Onions 336 4.8 1,613 -- 58% 677  Wheat 8,737 2.8 24,464 -- 58% 10,275  Barley 7,537 2.8 21,104 -- 58% 8,864  Lettuce 96 4.8 461 -- 58% 194 
Attachment-25

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

 Melons 6,529 4.8 31,339 -- 58% 13,162  Vegetables 2,352 4.8 11,290 -- 58% 4,742 

CU5c Reducing speed from 25.9 mph to 15 mph: (EF - Vehicle 

Traffic) 

60,026 

 Alfalfa 36,004 0.8 28,803 42% 42% 12,097  Citrus 4,464 2.46 10,981 42% 42% 4,612  Corn 6,241 0.8 4,993 42% 42% 2,097  Cotton 9,841 0.8 7,873 42% 42% 3,307  Onions 336 4.8 1,613 42% 42% 677  Wheat 8,737 2.8 24,464 42% 42% 10,275  Barley 7,537 2.8 21,104 42% 42% 8,864  Lettuce 96 4.8 461 42% 42% 194  Melons 6,529 4.8 31,339 42% 42% 13,162  Vegetables 2,352 4.8 11,290 42% 42% 4,742 

CU5d Reducing speed from 25.9 to 25 mph: (EF - Vehicle 

Traffic) 

60,026 

 Alfalfa 36,004 0.8 28,803 -- 3% 12,097  Citrus 4,464 2.46 10,981 -- 3% 4,612  Corn 6,241 0.8 4,993 -- 3% 2,097  Cotton 9,841 0.8 7,873 -- 3% 3,307  Onions 336 4.8 1,613 -- 3% 677  Wheat 8,737 2.8 24,464 -- 3% 10,275  Barley 7,537 2.8 21,104 -- 3% 8,864  Lettuce 96 4.8 461 -- 3% 194  Melons 6,529 4.8 31,339 -- 3% 13,162 
Attachment-26

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

 Vegetables 2,352 4.8 11,290 -- 3% 4,742 

CU6 Track Out Control: (EF - Vehicle 

Traffic) 

 (85% - 

95%) 

(No data at 

this time) 

128,628 

 Alfalfa 36,004 0.8 28,803 90% 0% 25,923  Citrus 4,464 2.46 10,981 90% 0% 9,883  Corn 6,241 0.8 4,993 90% 0% 4,494  Cotton 9,841 0.8 7,873 90% 0% 7,086  Onions 336 4.8 1,613 90% 0% 1,452  Wheat 8,737 2.8 24,464 90% 0% 22,017  Barley 7,537 2.8 21,104 90% 0% 18,993  Lettuce 96 4.8 461 90% 0% 415  Melons 6,529 4.8 31,339 90% 0% 28,205  Vegetables 2,352 4.8 11,290 90% 10,161 

CU7 Water Application: (EF - Vehicle 

Traffic) 

 (50% - 

93%) 

102,902 

 Alfalfa 36,004 0.8 28,803 72% 70% 20,738  Citrus 4,464 2.46 10,981 72% 70% 7,907  Corn 6,241 0.8 4,993 72% 70% 3,595  Cotton 9,841 0.8 7,873 72% 70% 5,668  Onions 336 4.8 1,613 72% 70% 1,161  Wheat 8,737 2.8 24,464 72% 70% 17,614  Barley 7,537 2.8 21,104 72% 70% 15,195  Lettuce 96 4.8 461 72% 70% 332  Melons 6,529 4.8 31,339 72% 70% 22,564  Vegetables 2,352 4.8 11,290 72% 70% 8,129 
Attachment-27

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

CU8 Wind Barrier - Artificial (reduces 

wind erosion of unpaved roads and non cropland):

(EF - Wind 

Erosion of 

Unpaved 

Roads & Non 

Cropland) 

 (0% - 90% 

Artificial 

Wind 

Barrier) 

30% 174,621 

Alfalfa 36,004 4.64 167,059 45% 30% 75,176 Citrus 4,464 4.21 18,793 45% 30% 8,457 Corn 6,241 4.21 26,275 45% 30% 11,824 Cotton 9,841 6.93 68,198 45% 30% 30,689 Onions 336 4.21 1,415 45% 30% 637 Wheat 8,737 4.21 36,783 45% 30% 16,552 Barley 7,537 4.21 31,731 45% 30% 14,279 Lettuce 96 4.21 404 45% 30% 182 Melons 6,529 4.21 27,487 45% 30% 12,369 Vegetables 2,352 4.21 9,902 45% 30% 4,456 

CU9 Wind Barrier - Natural (reduces wind 

erosion of unpaved roads and non cropland):

 (EF - Wind 

Erosion of 

Unpaved 

Roads & 

Non 

Cropland) 

 Tree, 

Shrub, or 

Windbreak 

Planting) 

25% 

97,012 

 Alfalfa 36,004 4.64 167,059 25% 30% 41,765  Citrus 4,464 4.21 18,793 25% 30% 4,698  Corn 6,241 4.21 26,275 25% 30% 6,569  Cotton 9,841 6.93 68,198 25% 30% 17,050  Onions 336 4.21 1,415 25% 30% 354  Wheat 8,737 4.21 36,783 25% 30% 9,196  Barley 7,537 4.21 31,731 25% 30% 7,933  Lettuce 96 4.21 404 25% 30% 101  Melons 6,529 4.21 27,487 25% 30% 6,872 
Attachment-28

Table A-1 – Potential PM10 Emission Reductions by Control Measure and Associated Cr

ID Control Measure by 

Associated Crop 

Acres by 

Crop / Land 

Use 

(Maricopa 

County PM10

Nonattainment 

Area)

PM10

Emission 

Factor 

(lbs / acre 

/yr) 

Uncontrolled 

PM10

Emissions 

 (lbs/yr) 

Maricopa 

BMP 

Control 

Efficiency 

(%) 

San Joaquin 

CMP 

Control 

Efficiency 

(%) 

PM10 Emissi

Reduction 

From 

Maricopa 

BMPs 

(lbs/yr) 

 Vegetables 2,352 4.21 9,902 25% 30% 2,475 
APPENDIX C 

Agricultural Best Management Practices Guidance 

Booklet and Pocket Guide 

The Governor’s Agricultural BMP Committee gratefully recognizes, thanks and appreciates the input, review suggestions, 

and overall support of many individuals and groups involved in this process.

Governor’s Agricultural BMP Committee:

Dan Thelander (Committee Chair), Grain Producer, Chandler Arizona

Wade Accomazzo, Alfalfa Producer, Tolleson, Arizona

Don Butler, Director, Arizona Department of Agriculture, Phoenix, Arizona

(Designee Brett Cameron, Assistant Director, Agricultural Consultation and Training, 

 Arizona Dept. of Agriculture, Phoenix, Arizona)

Alfred Lopez, Citrus Producer, Sun City, Arizona

Kevin G. Rogers, Cotton Producer, Mesa, Arizona

Will Rousseau, Vegetable Producer, Litchfield Park, Arizona

Eugene G. Sander, Vice Provost and Dean, College of Agriculture and Life Sciences, University of Arizona, Tucson, Arizona

(Designee Colin Kaltenbach, Director of Agricultural Experiment Stations, University of Arizona, Tucson, Arizona)

Stephen A. Owens, Director, Arizona Department of Environmental Quality, Phoenix, Arizona

(Designee Nancy Wrona, Director, Air Quality Division, Arizona Department of Environmental Quality, Phoenix, Arizona)

Dave McKay, State Conservationist, Natural Resource Conservation Service, Phoenix, Arizona

James L. Walworth, Soil Scientist, College of Agriculture and Life Sciences, University of Arizona, Tucson, Arizona

Ag BMP Technical Work Group:

Rick Ladra (Co-Chair) Cotton Producer, Buckeye, Arizona

Kevin G. Rogers (Co-Chair) Cotton Producer, Mesa, Arizona

Brett Cameron, Arizona Department of Agriculture, Phoenix, Arizona

Kristin Graham-Chavez, Natural Resource Conservation Service, Phoenix, Arizona

Pat Clay, Field Market Development Specialist, Maricopa, Arizona

Jeannette Fish, Maricopa County Farm Bureau, Phoenix, Arizona

Cheryl Goar, Arizona Nursery Association, Phoenix, Arizona

Jim Klinker, Arizona Farm Bureau Federation, Higley, Arizona

Rick Lavis, Arizona Cotton Grower’s Association, Phoenix, Arizona

Andrea Martin, Arizona Department of Agriculture, Phoenix, Arizona

Russell Van Leuven, Arizona Department of Agriculture, Phoenix, Arizona

Steven Peplau, Arizona Department of Environmental Quality, Phoenix, Arizona

Randy Sedlacek, Arizona Department of Environmental Quality, Phoenix, Arizona

Robert L. Shuler, Attorney, Ryley, Carlock & Applewhite, for Western Growers Association

Joe Sigg, Arizona Farm Bureau Federation, Higley, Arizona

Wienke Tax, EPA Region 9, Tucson, Arizona

James L. Walworth, Soil Scientist, University of Arizona, Tucson, Arizona 

Staff assigned to Governor’s Ag BMP Committee:

Deborrah “Corky” Martinkovic, Planning Unit Supervisor

Lisa Tomczak, Environmental Program Specialist

Air Quality Division, Arizona Department of Environmental Quality, Phoenix, Arizona

Funding support for printing of this guide was provided by a US Environmental Protection Agency 105 Air Quality Grant to 

the Arizona Department of Agriculture, Agricultural Consultation and Training Program through the Arizona Department of 

Environmental Quality, Air Quality Division.

Governor’s Agricultural BMP Acknowledments

First Edition 2001

Second Edition 2008
Where can I learn more? ..............................................................................................................................................................4

Introduction.................................................................................................................................................................................5

Why is this Guide to Agricultural PM10 Best Management Practices needed?..........................................................................5

Why was the agricultural PM10 general permit created?............................................................................................................5

Who must comply with the agricultural PM10 general permit?..................................................................................................6

What does the farmer have to do?................................................................................................................................................6

When must the agricultural PM10 general permit be implemented? ..........................................................................................6

What will happen if I do not comply with the agricultural PM10 general permit? .....................................................................6

Where does the agricultural PM10 general permit apply?...........................................................................................................6

Soils, PM10, and Air Quality.....................................................................................................................................................7

Best Management Practices.......................................................................................................................................................8

Category I: Tillage and Harvest................................................................................................................................................9

Cessation of Night Tillage ...........................................................................................................................................................9

Chemical Irrigation ......................................................................................................................................................................9

Combining Tractor Operations ...................................................................................................................................................10

Equipment Modification .............................................................................................................................................................10

Green Chop .................................................................................................................................................................................10

Integrated Pest Management.......................................................................................................................................................11

Limited Activity during a High-Wind Event ..............................................................................................................................11

Multi-Year Crop..........................................................................................................................................................................12

Planting Based on Soil Moisture.................................................................................................................................................12

Precision Farming .......................................................................................................................................................................13

Reduced Harvest Activity ...........................................................................................................................................................13

Reduced Tillage System..............................................................................................................................................................13

Tillage Based on Soil Moisture...................................................................................................................................................14

Timing of a Tillage Operation.....................................................................................................................................................14

Transgenic Crops ........................................................................................................................................................................14

Category II: Non-cropland........................................................................................................................................................15

Access Restriction.......................................................................................................................................................................15

Aggregate Cover.........................................................................................................................................................................15

Artificial Wind Barrier................................................................................................................................................................16

Critical Area Planting..................................................................................................................................................................16

Manure Application ....................................................................................................................................................................16

Reduce Vehicle Speed.................................................................................................................................................................17

Synthetic Particulate Suppressant...............................................................................................................................................17

Track-out Control System...........................................................................................................................................................18

Tree, Shrub or Windbreak Planting.............................................................................................................................................19

Watering......................................................................................................................................................................................19

Guide to Agricultural PM10 Best Management Practices

Table of Contents
Category III: Cropland.............................................................................................................................................................20

Artificial Wind Barrier................................................................................................................................................................20

Cover Crop..................................................................................................................................................................................21

Cross-Wind Ridges.....................................................................................................................................................................21

Cross-Wind Strip-Cropping ........................................................................................................................................................22

Cross-Wind Vegetative Strips.....................................................................................................................................................22

Integrated Pest Management.......................................................................................................................................................23

Manure Application ....................................................................................................................................................................23

Mulching.....................................................................................................................................................................................24

Multi-Year Crop..........................................................................................................................................................................24

Permanent Cover.........................................................................................................................................................................25

Planting Based on Soil Moisture.................................................................................................................................................25

Residue Management..................................................................................................................................................................26

Sequential Cropping....................................................................................................................................................................26

Surface Roughening....................................................................................................................................................................27

Transgenic Crops ........................................................................................................................................................................27

Tree, Shrub or Windbreak Planting.............................................................................................................................................28

Sample Agricultural BMP General Permit Record................................................................................................................29

PM10 Nonattainment Area & Area A Map.......................................................................................................................Insert

Guide to Agricultural PM10 Best Management Practices

Table of Contents
--

If you do not know whether your agricultural operation resides within the PM10 Nonattainment Area, or if you have 

questions regarding compliance or specific components of the agricultural PM10 general permit, contact:

Arizona Department of Agriculture

Agricultural Consultation & Training 

1688 W. Adams St.

Phoenix, AZ 85007

602-542-3484

800-294-0308

www.azda.gov/ACT/AirQuality.htm

Agua-Fria New River NRCD

16251 W. Glendale Ave.

Litchfield Park, AZ 85340

602-771-4162

www.nrcd.org/aguafria/

Arizona Cotton Growers Association

4139 E. Broadway Rd.

Phoenix, AZ 85040

602-437-1344

acga1@aol.com

Arizona Nursery Association

1430 W. Broadway Rd.

Suite#110 

Tempe, AZ 85282

480-966-1610

www.azna.org 

Buckeye Valley NRCD

220 N. 4th St.

Buckeye, AZ 85326

602-386-7350

www.nrcd.org/buckeyevalley/

Arizona Department of Environmental Quality

Air Quality Division

1110 W. Washington St.

Phoenix, AZ 85007

602-771-2300

800-234-5677

www.azdeq.gov/environ/air/index.html

East Maricopa NRCD

18256 E. Williams Field Rd. 

Suite #1

Higley, AZ 86236

480-988-1078

www.nrcd.org/eastmaricopa/

FSA Service Center Office

Maricopa County 

Farm Service Agency

12409 W. Indian School Rd. 

Building B Ste. 201

Avondale, AZ 85323

623-535-5055 ext 2

www.fsa.usda.gov/az/

Maricopa County Cooperative Extension

4341 E. Broadway Rd.

Phoenix, AZ 85040

602-470-8086

www.cals.arizona.edu/maricopa/

Maricopa County Farm Bureau

4001 E. Broadway Rd. 

Suite #B9

Phoenix, AZ 85040

602-437-1330

MCFB@qwestoffice.net

Where can I learn more?
5

Why is the Guide to Agricultural PM10

Best Management Practices needed?

The Federal Clean Air Act requires that emissions from 

all significant sources in areas not meeting the national 

ambient air quality standards be controlled through 

effective programs. Through a study conducted by the 

Arizona Department of Environmental Quality (ADEQ) 

in 1995, agricultural activities were identified as a source 

that contributes to the production of particulate matter 

(PM). 

PM10 is particulate matter that is 10 micrometers or 

less in diameter (as compared to a human hair that is 

about 70 micrometers). These particles are very small 

and can invade the natural defense mechanism of the 

human respiratory tract, penetrating deep into the lungs. 

Consequently, PM10 can cause a wide variety of harmful 

health effects, especially for children, the elderly, and 

people with pre-existing respiratory or cardiovascular 

disease.

With this threat to human health, coupled with repeated 

violations of the federal health standard for PM10, 

public agencies and industry groups in the Phoenix 

metropolitan area have developed and are implementing 

programs to help the area meet the federal clean air 

standards for PM10.

The intent of this guide is to:

• Provide agricultural operators with information and 

guidance on how to effectively implement individual 

best management practices (BMPs).

• Inform the general public about the efforts Maricopa 

County farmers are implementing to improve air 

quality.

• Provide Natural Resource Conservation Districts 

(NRCD) and other farm organizations with 

background information regarding the agricultural 

PM10 general permit.

Provide regulators with information and guidance on 

how to determine compliance with the agricultural 

PM10 general permit.

•

Why was the agricultural PM10 

general permit created?

The Phoenix metropolitan area has not met the Federal 

Clean Air Act Standards for PM10 since the Clean Air 

Act was revised in 1990. On June 10, 1996, the U.S. 

Environmental Protection Agency (EPA) redesignated 

the Moderate PM10 Nonattainment Area to Serious, 

resulting in the need for emission reduction programs for 

previously unregulated sources, such as unpaved roads, 

unpaved parking lots, vacant lots and agriculture. On 

August 3, 1998, EPA issued a federal implementation 

plan (FIP) addressing these unregulated sources. The FIP 

included requirements to develop and enforce control 

measures for these source categories. 

To address agriculture’s contribution to PM10, the 

Governor’s Agricultural Best Management Practices 

Committee was created by law in 1998 (Arizona Revised 

Statutes (A.R.S.) §49-457). The Committee’s charge 

was to develop an agricultural PM10 general permit 

that would include controls on agricultural operations. 

The Committee was to identify BMPs that focused on 

feasible, effective and common sense practices that 

minimized negative impacts on local agriculture. In 

the original program, the agricultural PM10 general 

permit required that at least one BMP be implemented to 

control PM10 for each of the following three categories: 

tillage and harvest, non-cropland and cropland. In 2007, 

the Arizona State Legislature passed Senate Bill 1552, 

changing the number of BMPs required from one to 

two BMPs per category. The Committee is composed of 

five local farmers, the Director of ADEQ, the Director 

of Arizona’s Department of Agriculture, the State 

Conservationist for the Natural Resources Conservation 

Service (NRCS), the Dean of the University of Arizona 

College of Agriculture and Life Sciences, and a soil 

taxonomist from the University of Arizona. After A.R.S. 

§49-457 was developed and adopted, EPA removed 

the portion of the Federal Implementation Plan for 

agriculture on June 29, 1999 [64 Federal Register p. 

34726].

Introduction
- -

Who must comply with the agricultural PM10 general 

permit?

Any farmer who farms more than 10 contiguous 

acres of land located within the Maricopa PM10 

Nonattainment Area and Maricopa County Portion of 

Area A (reference map insert) must comply with the 

agricultural PM10 general permit. 

What does the farmer have to do?

• Implement and maintain at least two approved 

BMPs (described later in this document) for each 

of the three categories: tillage and harvest, noncropland and cropland.

• Keep records detailing the BMPs selected for each 

category. The commercial farmer may document 

the practice on the sample BMP agricultural PM10 

permit record or develop a record that includes 

the information required by the agricultural PM10 

general permit. The commercial farmer must make 

available the record to the ADEQ director within 

two business days of notice to the farmer.

• The Committee recommends additional record 

keeping if implementation of the BMPs is not 

easily visible. Examples of additional record 

keeping include, but are not limited to, photographs, 

purchase records, receipts, job sheets, contractor 

invoices, employee timesheets, logs, narrative 

statements, individual farm policies, statements of 

understanding signed by employees or contractors, 

and training records.

• No fee is associated with the agricultural PM10 

general permit.

When must the agricultural PM10 

general permit be implemented?

A farmer engaged in agricultural activities before June 

10, 2000 must comply with the agricultural PM10 

general permit by December 31, 2001. A commercial 

farmer who engages in agricultural activities after 

December 31, 2000, has 18 months to comply with the 

agricultural PM10 general permit. 

Legislation enacted in 2007 requires that all farmers 

engaged in agricultural activities must comply with 

the agricultural PM10 program by December 31, 

2007, as revised by the Governor’s Agricultural BMP 

Committee.

What would happen if I do not comply with the 

agricultural PM10 general permit?

If the ADEQ director determined that a commercial 

farmer is not in compliance with the agricultural PM10 

general permit, the following three-stage process would 

occur: 

If the farmer has not previously been subject to an 

agricultural general permit related compliance order, 

the farmer would be required to submit a plan to the 

local NRCD. The plan must specify the BMPs that 

the farmer would use to comply with the general 

permit.

If the farmer has previously been subject to an 

agricultural PM10 general permit related compliance 

order, the farmer would be required to submit a plan 

to ADEQ that specifies the BMPs that the farmer 

would use to comply with the general permit.

If the farmer failed to comply with the plan 

submitted to NRCD and ADEQ, the director of 

ADEQ may revoke the agricultural PM10 general 

permit and require the farmer to obtain an individual 

fee based permit.

At each stage, the farmer would have the opportunity

for a hearing.

Where does the agricultural PM10 

general permit apply?

Any agricultural operation greater than 10 contiguous 

acres within the Maricopa PM10 Nonattainment Area 

and Maricopa County Portion of Area A (reference map 

insert), except on tribal lands, must comply with the 

agricultural PM10 general permit. 

1.

2.

3.
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Soils consist of various particles including mineral matter, organic matter, air, and 

water. These particles vary in shape and size, ranging from large 

drops of liquid to microscopic dust particles. The 

mineral particles in soil are classified as sand, silt, or 

clay. Soils containing high amounts of clay coupled 

with large silt particles have a greater likelihood of 

generating PM10. 

When the natural soil structure is manipulated or 

disturbed by tillage, animals, weather, or vehicular 

traffic, the structure can be broken apart from larger 

pieces, or clods, into smaller pieces. This process 

significantly increases the potential for soil particles to 

become suspended in the air. Further manipulation of the 

soil increases the chance for smaller particles to become 

PM10. 

Air quality problems occur when the amount of particles released into the air increase in concentration. Large 

concentrations of PM10 could potentially violate one of the federal air quality standards, or National Ambient 

Air Quality Standards (NAAQS), set for various air pollutants. The current NAAQS standard for PM10 is 150 

micrograms/cubic meter averaged over 24 hours. This standard is a concentration by weight measure. PM10 

emissions can also cause visibility impairment (e.g., Brown Cloud) as well as health impacts. The small particles 

can pass through nostril hairs and enter the lungs, penetrating deep into the lung tissue where it is lodged and not 

easily, if ever, expelled. 

Two meteorological events have the potential to increase the impacts from high concentrations of PM10: high winds 

and stagnation. Conditions for both of these events can occur in the Phoenix area, one occurring predominantly in 

the warmer season, the other in the cooler season. Warm season high wind events are generally short (less than one 

hour) and are the result of the downdrafts from monsoon thunderstorms. The cool season events are longer (six to 

12 hours) and are the result of strong pressure gradients associated with a trough or a cold front. An inversion is a 

region in the atmosphere where the temperature increases with height. The presence of an inversion creates a very 

stable atmosphere and leads to very little mixing of the air, trapping pollutants close to the ground. An inversion 

is also produced whenever radiation from the surface exceeds the amount of radiation from the sun – commonly 

at night or in the winter when the angle of the sun is very low in the sky. Some of the best management practices 

outlined in this booklet address how to lower PM10 so these events do not increase PM10 concentrations.

Disturbed soil that is broken down into smaller particles can also become a soil conservation problem. Many 

of the best management practices outlined in this booklet are already used to prevent soil erosion. Other best 

management practices address ways of limiting PM10 from associated farming activities such as adjoining dirt roads 

Soils, PM10 and Air Quality
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or road shoulders on farmland. The manipulation or disturbance of soil is inherent to the practice of farming. Best 

management practices are not designed to eliminate particle emissions 100 percent, but they are designed to reduce 

the activities that can lead to the increased concentration of PM10.

As a result of discussions between the EPA, Arizona Department of Environmental Quality, and the Arizona 

Department of Agriculture, the Arizona State Legislature in 1999 enacted legislation with the full support of the 

Arizona agriculture community to create and implement a Best Management Practice Program. The Agricultural 

Best Management Practice Program allows growers a wide range of choices to reduce PM10 emissions within the 

established Maricopa PM10 Nonattainment Area and Maricopa County Portion of Area A (reference map insert). 

The Arizona Legislature has defined a BMP for the Maricopa PM10 Nonattainment Area and Maricopa County 

Portion of Area A (reference map insert) as a technique verified by scientific research that is practical, economically 

feasible and effective in reducing PM10 on a case by case basis from a regulated agricultural activity. The following 

section summarizes the BMPs approved by the Governor’s Agricultural Best Management Practices Committee 

to reduce PM10 for each of the three agricultural categories: tillage and harvest, non-cropland and cropland. A

wide range of variation in soils and cropping systems exists within the Maricopa PM10 Nonattainment Area and 

Maricopa County Portion of Area A (reference map insert), which can only be addressed by a wide range of flexible 

and adaptable management practices. Most methods for controlling PM10 emissions parallel the controls for wind 

erosion. These methods are based on principles that contain or slow soil movement from fields. Not all of the BMPs 

will work equally well on every farm because of variations in wind, soils, cropping systems, moisture conditions 

and, in some cases, the management approaches of individual growers. Such factors should be considered by the 

individual farmer to ensure he or she implements effective BMPs. This guide represents steps in helping farmers 

reduce PM10 emissions from farmlands located within the Maricopa PM10 Nonattainment Area and Maricopa 

County Portion of Area A (reference map insert). 

Best Management Practices
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Any mechanical practice that physically disturbs cropland or crops on a commercial farm.

Best management practices for use during tillage and harvest

Cessation of Night Tillage

Chemical Irrigation 

Combining Tractor Operations 

Equipment Modification 

Green Chop

Integrated Pest Management 

Limited Activity during a High-Wind Event 

Multi-Year Crop 

Planting Based on Soil Moisture 

Precision Farming 

Reduced Harvest Activity 

Reduced Tillage System 

Tillage Based on Soil Moisture 

Timing of a Tillage Operation 

Transgenic Crops

Cessation of Night Tillage

Rule Definition 

“Cessation of Night Tilling” means the discontinuance of night tilling on high pollution advisory (hpa) days during 

stagnant air conditions. See night tilling rule definition.

Purpose

Cessation of night tillage between 2:00 a.m. and 8:00 a.m. to decrease the 

concentrations of PM emissions at night when stagnant air conditions with 

little if any vertical mixing of the air occurs and a high pollution advisory has 

been given.

Suggestions for Implementation

An individual farm policy should be developed to ensure that no tillage activities occur during stagnant air conditions 

on HPA days. Notification of HPAs are broadcast by noon of the day prior to the HPA in the media, by e-mail, and by 

text message. Employees should receive training in implementing the farm policy.

Chemical Irrigation

Rule Definition

“Chemical Irrigation” means applying fertilizer, pesticide, or other agricultural chemicals to cropland through an 

irrigation system.

Purpose

Chemical irrigation reduces the number of passes across a field with tractors, sprayers, fertilizer applicators and 

machinery. Reducing the number of field operations reduces the emissions associated with those activities.

Suggestions for Implementation

All product application recommendations should be followed to ensure proper implementation.

The field operations eliminated should be documented to demonstrate the implementation of the practice.

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Category 1: Tillage and Harvest
-10-

Combining Tractor Operations

Rule Definition

“Combining Tractor Operations” means performing two or more tillage, 

cultivation, planting, or harvesting operations with a single tractor or 

harvester pass.

Purpose

Combining tractor operations reduces the number of passes or trips that a 

tractor, implement, harvester or other farming support vehicle makes across a 

field or unpaved surface, thereby reducing the amount of soil disturbed.

Suggestions for Implementation

Combining tractor operations is most effective if implemented during the 

time of year when PM10 is most likely to be produced. 

Applying fertilizer and herbicide in a single pass.

Cultivating and fertilizing in a single pass. Using specialized machinery to bury stalks make new furrows in a 

single pass.

Combining multiple heavy tillage operations in a single pass, for example, pulling a ring roller behind a disc.

Equipment Modification

Rule Definition

“Equipment Modification” means modifying agricultural equipment to prevent or reduce particulate matter 

generation from cropland.

Purpose

Modifying and maintaining an existing piece of agricultural equipment or purchasing new equipment to prevent 

PM10 from becoming airborne during tillage and harvest operations, which helps reduce PM10 and soil erosion.

Examples of Equipment Modification

Shields or deflectors that redirect fan or vehicle exhaust sideways or upward. This can prevent PM10 from 

becoming airborne because exhaust is not blowing downward on the soil surface.

Dust shrouds around tillage implements and harvesters.

Spray bars that emit a mist to knock down PM10.

Green Chop

Rule Definition 

“Green Chop” means the harvesting of a forage crop without allowing it to dry in the field.

Purpose 

Green chop reduces multiple equipment passes in-field as well as reduces 

soil disturbance and soil compaction.

Examples of Green Chop

• Alfalfa

• Winter forage

• Silage corn

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-11-

Integrated Pest Management

Rule Definition

“Integrated Pest Management” means the use of a combination of 

techniques including organic, conventional and biological farming 

practices.

Purpose

Integrated pest management creates beneficial insect habitat that reduces 

the use of herbicides/ pesticides, thereby reducing the number of passes 

for spraying. It also reduces soil compaction and the need for additional 

tillage.

Examples of Integrated Pest Management

Monitoring crop for pests to accurately and effectively apply control measures.

Incorporate biological practices into farming operation to reduce need for spraying.

Limited Activity during a High-Wind Event

Rule Definition

“Limited activity during a High-Wind Event” means performing no tillage or soil preparation activity when the 

measured wind speed at 6 feet in height is more than 25 mph at the commercial farm site.

Purpose

Because this BMP falls within the tillage and harvest category, it also applies during harvest time. Wind speed, 

temperature and relative humidity affect the distance that PM10 travels and the ability for PM10 to be suspended 

in the air. Limiting activity during a high-wind event will reduce the transport of PM10. Reducing farm operations 

during a high wind event, as well as when the wind speed is less than 25 mph, can significantly help reduce PM10 

emissions.

Suggestions for Implementation

A device to measure wind speed should be available at the commercial farm site.

An individual farm policy should be developed to ensure that no tillage or soil preparation activities occur when 

the wind speed reaches 25 mph. 

Employees and family members should receive training in implementing the farm policy.

Subscribe to the Dust Action Forecast issued by ADEQ. Notification of Dust Action Forecasts are broadcast by 

mid­-morning of the day prior to the high-wind event. 

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-12-

Multi-Year Crop

Rule Definition

“Multi-Year Crop” means a crop, pasture, or orchard that is grown, or will be grown, on a continuous basis for more 

than one year.

Purpose

Surface covers, such as crops, pasture and orchards that are grown and maintained for a long duration, protect the 

soil surface from erosive winds. The longer a crop or cover is protecting the soil surface, the less time the surface is 

susceptible to wind erosion.

Examples of Multi-Year Crops include

Alfalfa

Citrus

Roses

Livestock pastures

Nuts (Pecans)

Sod

Planting Based on Soil Moisture

Rule Definition

“Planting Based on Soil Moisture” means applying water to soil before performing planting operations.

Purpose

Planting based on soil moisture reduces PM10 during the planting operation and is effective from the time of

planting until crop establishment. Planting based on soil moisture is one of the most efficient practices to reduce 

PM10 between planting and crop emergence. Moisture causes soil to crust and therefore PM10 is not easily 

transported into the air.

Suggestions for Implementation

Care should be taken to avoid over compaction of the soil, which could result in additional tillage operations. 

Irrigation should be applied as soon after soil preparation for planting as possible. After watering, a thin crust 

develops on the soil surface, which stabilizes it until planting. 

The time between bed lifting, irrigation and planting should be minimized as much as possible.

Use the soil moisture “feel method” to determine adequate soil moisture. See the Natural Resource Conservation 

Service Publication #1619 “Estimating Soil Moisture by Feel and Appearance.” This publication is available at 

all NRCD offices.

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Precision Farming

Rule Definition

“Precision Farming” means using GPS to precisely guide farm equipment in the 

field.

Purpose

Precision farming reduces overlap and allows operations to occur during inclement 

weather conditions and at night thereby generating less PM.

Examples of Precision Farming

Install overlap reduction technology

Pass markers

Variable rate application technology

Reduced Harvest Activity

Rule Definition

“Reduced Harvest Activity” means reducing the number of harvest passes using a mechanized method to cut and 

remove crops from a field.

Purpose

Any time an operation takes place in a field, the soil structure can be 

modified and some PM10 could be released into the air. Reducing the 

number of harvest activities can keep the soil structure intact and reduce 

PM10.

Suggestions for Implementation

An example of reduced harvest activity is the elimination of a harvest or 

rood pass from a cotton harvest. More PM10 is emitted during a normal 

cotton harvest season because the process requires several harvest passes 

to remove most of the crop from the plant. The rood process produces a 

significant amount of PM10 because of the nature of the operation.

Reduced Tillage System

Rule Definition

“Reduced Tillage System” means reducing the number of tillage operations used to produce a crop.

Purpose

Any tillage operation in a field can modify the soil structure and possibly release PM10 into the air. Reducing the 

number of tillage activities can maintain the soil structure and help reduce PM10.

Suggestions for Implementation

Minimum tillage system*

Mulch tillage system*

Reduced tillage system*

*Consult NRCS Standard and Specifications, 329 and 344, Residue Management. This document is available at all 

NRCD offices.

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-14-

Tillage Based on Soil Moisture

Rule Definition

“Tillage Based on Soil Moisture” means applying water to soil before or during tillage, or delaying tillage to 

coincide with precipitation.

Purpose

Moisture binds soil particles and helps reduce the amount of PM10 released into the air. Fine dry soil can easily 

erode with increased wind speeds. Sufficient moisture levels can be achieved by irrigating before tillage or tilling 

after rain. Moisture can also allow large soil clods to form, after tillage, which reduces wind erosion.

Suggestions for Implementation

Fields should be irrigated to the depth of proposed cut prior to soil disruption, or tillage should be conducted to 

coincide with precipitation.

The application of moisture or the date of tillage that coincided with precipitation should be documented.

The soil moisture “feel method” should be used as a way to determine adequate soil moisture. See the Natural 

Resource Conservation Service publication #1619 “Estimating Soil Moisture by Feel and Appearance”. This 

publication is available at all NRCD offices.

Timing of a Tillage Operation

Rule Definition

“Timing of a Tillage Operation” means performing tillage operations at a time that will minimize the soil’s 

susceptibility to generate PM10.

Purpose

Adjusting the time of tillage operations can minimize the amount of time the soil surface is susceptible to wind 

erosion and generation of PM10. When a field’s surface is smooth, dry, and consists of finer grained soil particles, 

the field is most susceptible to wind erosion, resulting in PM10.

Some examples of timing of tillage operations to reduce PM10 generation include:

Reducing time between leveling (land planing) and bedding, which is when the beds act as miniature

windbreaks. For example, a cotton production system where fields are tilled in the fall, land planed, and then 

bedded, would be less susceptible to wind erosion and PM10.

Leaving the field surface with large soil clods for as long as possible prior to preparation of seed beds.

Transgenic Crops

Rule Definition

“Transgenic Crops” means the use of plants that are genetically modified.

Purpose

Transgenic crops reduce need for tillage or cultivation operations, as well as reduces 

soil disturbance. Can also reduce the number of chemical applications.

Examples of Transgenic Crops

Genetically altered seed

Nematode resistant rootstock

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Any commercial farm land that:

• Is no longer used for agricultural production,

• Is no longer suitable for production of crops,

• Is subject to a restrictive easement or contract that prohibits use for the production of crops, or includes a 

private farm road, ditch, ditch bank, equipment yard, storage yard or well head.

Best management practices for use on non-cropland

Access Restriction

Aggregate Cover

Artificial Wind Barrier

Critical Area Planting

Manure Application

Reduce Vehicle Speed

Synthetic Particulate Suppressant

Track-out Control System

Tree, Shrub or Windbreak Planting

Watering

Access Restriction

Rule Definition

“Access Restriction” means restricting or eliminating public access to non-cropland with signs or physical 

obstruction.

Purpose

Reducing the number of trips driven on agricultural aprons and access roads can 

reduce that area’s susceptibility to PM10.

Examples of methods to restrict access include, but are not limited to:

• Installing physical barriers such as gates, fencing, posts, signs, shrubs, trees or 

other physical obstructions to prevent or control access to the area.

• Installing “no trespassing” or “limited use area” signs.

Aggregate Cover

Rule Definition

“Aggregate Cover” means gravel, concrete, recycled road base, caliche or other similar material applied to noncropland.

Purpose

Applying an aggregate cover to unpaved farm roads, parking areas and canal 

banks helps reduce the amount of soil particles exposed to the surface, thus 

helping to reduce the generation of PM10. Aggregate cover acts as a surface 

barrier to erosive forces like wind or vehicle traffic.

Suggestions for Implementation

The aggregate should be one inch or larger in diameter.

The aggregate should be applied a minimum of four inches deep.

The aggregate material should be clean, hard and durable.

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CATEGORY II: Non-Cropland
-16-

Artificial Wind Barrier

Rule Definition

“Artificial Wind Barrier” means a physical barrier to the wind.

Purpose

Artificial wind barriers disrupt the erosive flow of wind over 

unprotected areas thus helping to reduce PM10.

Suggestions for Implementation

Continuous board fences, burlap fences, crate walls, bales of 

hay and similar material can be used to control air currents and 

blowing soil.

Barriers should be aligned across the prevailing wind 

direction. While 90 degrees or perpendicular is preferred, 

benefits can still be realized when barriers are aligned as close 

to perpendicular as possible.

The distance of 10 times the barrier height is considered the 

protected area downwind of the barrier.

Critical Area Planting

Rule Definition

“Critical Area Planting” means using trees, shrubs, vines, grasses, or other vegetative cover on non-cropland.

Purpose

Critical area planting helps control soil movement and protect the soil surface when adequate cover does not exist. 

Ground covers reduce dust and wind erosion by shielding the soil with vegetation and anchoring the soil with roots. 

This practice applies to field aprons, equipment parking areas, turn rows, canal banks, canal excavation spoil piles 

and bare areas where vegetation is difficult to establish by usual planting methods.

Suggestions for Implementation

Critical area planting consists of any vegetative cover that maintains more than 60 percent ground cover.

Manure Application

Rule Definition

“Manure Application” means applying animal waste or biosolids to a soil surface.

Purpose

Applying manure to maintain or improve chemical and biological condition of the soil can help reduce wind erosion 

and PM10.

Suggestions for Implementation

If the application or storage of manure is near a water source, precautions should be taken to prevent accidental 

leakage, spillage or runoff that will result in undesirable effects on soil, water and plants.

Caution should be used when applying manure to ensure that state and local regulations are not violated.

Caution should be used when certain manures are applied as they can volatilize and contribute to odor and 

ammonia emissions.

Manures should be incorporated as quickly as possible to reduce odor and ammonia emissions, and to preserve 

nutrient value if the area is to be cropped in the future.

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Reduce Vehicle Speed

Rule Definition

“Reduce Vehicle Speed” means operating farm vehicles or farm equipment on 

unpaved private farm roads at speeds not to exceed 20 mph.

Purpose

Reduced speeds can decrease the amount of PM10 generated by vehicles or 

equipment on unpaved farm roads.

Examples of methods to reduce vehicle speed include, but are not limited to:

• Posting speed limit signs.

• Informing all employees, contractors and sub-contractors of speed limits.

• Placing signs in all farm vehicles stating the speed limits on farm roads.

• Installing speed bumps.

Synthetic Particulate Suppressant

Rule Definition

“Synthetic Particulate Suppressant” means a manufactured product such as lignosulfate, calcium chloride, 

magnesium chloride, an emulsion of a petroleum product, an enzyme product, and polyacrylamide that is used to 

control particulate matter.

Purpose

Synthetic particulate suppressants provide a surface barrier or bind soil particles together to retard PM10 on 

unprotected areas, such as unpaved roads, rights-of-way and abandoned fields.

Examples of synthetic particulate suppressant include, but are not limited to:

• Calcium chloride (CaCl)

• Soybean feedstock (SBF) processing byproducts

• Calcium lignosulfonate (lignin)

• Polyvinyl acrylic polymer emulsion (PVA)

• Polyacrymide (PAM)

• Emulsified petroleum resin

Differences in traffic type and volume, soil types, roadway surface characteristics and topography between 

sites requiring dust control can cause product performance to vary. Consult the NRCD office or a dust control 

contractor for specific recommendations. All products should be applied strictly in accordance with manufacturers’ 

specifications.
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Track-out Control System

Rule Definition

“Track-out Control System” means a device to remove mud or soil from a vehicle before the vehicle enters a paved 

public road.

Purpose 

Using a track-out control system helps remove mud and soil from the tires of farm equipment and vehicles before 

they enter a paved public road, where the mud or soil can be crushed into fine particles and easily suspended in the

air by passing vehicles.

Suggestions for Implementation

Some examples of track-out control systems are:

Grizzly - a device similar to a cattle guard, which is used to dislodge mud, dirt or debris from the tires and 

undercarriage of equipment and vehicles prior to leaving a farm.

Gravel pad - a pad of crushed stone, coarse gravel or recycled road base located at the point of intersection of a 

paved public roadway and a farm entrance.

It is recommended that:

a) The stone or gravel is one inch or larger in diameter.

b) The gravel pad is applied a minimum of four inches deep.

c) The gravel pad is the full width of the farm entrance.

d) The gravel pad is a minimum of 50 feet long.

Pavement – an area of asphalt, concrete or similar material applied to a farm road at the intersection of a paved 

public roadway and a farm entrance. 

It is recommended that:

a) The pavement is the width of the farm road.

b) The pavement is a minimum of 100 feet long from the point of intersection with a paved public roadway.

The farm entrance should be maintained in a condition that will prevent tracking of mud and soil onto paved public 

roads. The farmer should conduct periodic inspections, maintenance, re-application of gravel and cleaning of paved 

access road surfaces to accomplish track-out control.

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Tree, Shrub, or Windbreak Planting

Rule Definition

“Tree, Shrub, or Windbreak Planting” means providing a woody vegetative barrier to the wind.

Purpose

Barriers placed perpendicular to the wind direction can reduce wind speeds by changing the pattern of airflow over 

the land surface, which helps reduce wind erosion and PM10.

Suggestions for Implementation

• The distance of 10 times the barrier height is considered the protected 

area downwind of the barrier.

• Single row plantings are most popular in field windbreaks because they 

use less water and occupy the least amount of land area for the amount 

of protection derived.

• Recommended species for planting can be obtained at all NRCD 

offices.

• The planting should be done at a time and manner to ensure survival 

and growth of selected species.

• Moisture conservation or supplemental watering should be provided for plant establishment and growth, as well 

as the use of drought tolerant species.

• Windbreaks should be aligned across the prevailing wind direction. While 90 degrees or perpendicular is 

preferred, benefits can still be realized when windbreaks are aligned as close to perpendicular as possible.

• The interval between windbreaks should be determined using current approved wind erosion technology, 

available at all NRCD offices.

Watering

Rule Definition

“Watering” means applying water to non-cropland.

Purpose

Applying water from a truck, tractor or other portable spray system to bare soil surfaces, such as unpaved roadways 

and equipment yards where high traffic areas exist, can help reduce PM10. Watering the soil surface tends to 

compact the soil so that it is not dispersed into the air.

Suggestions for Implementation

Watering is effective during peak usage times, such as silage harvest time.

• Apply water so that the surface is visibly moist.
-20-

Land on a commercial farm that:

•	 Is within the timeframe of final harvest to plant emergence,

• Has been tilled in a prior year and is suitable for crop production, but is currently fallow, or

• Is a turn-row.

Best management practices for use on cropland

Artificial Wind Barrier

Cover Crop

Cross-Wind Ridges

Cross-Wind Strip-Cropping

Cross-Wind Vegetative Strips

Integrated Pest Management

Manure Application

Mulching

Multi-Year Crop

Permanent Cover

Planting Based on Soil Moisture

Residue Management

Sequential Cropping

Surface Roughening

Transgenic Crops

Tree, Shrub, or Windbreak planting

Artificial Wind Barrier

Rule Definition

“Artificial Wind Barrier” means a physical barrier to the wind.

Purpose

Artificial wind barriers disrupt the erosive flow of wind over unprotected cropland fields thus helping to reduce 

PM10.

Suggestions for Implementation

Continuous board fences, burlap fences, crate walls, bales of hay and similar material can be used to control air 

currents and blowing soil.

Barriers should be aligned across the prevailing wind direction. While 90 degrees or perpendicular is preferred, 

benefits can still be realized when barriers are aligned as close to perpendicular as possible.

The distance of 10 times the barrier height is considered the protected area downwind of the barrier.

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CATEGORY III: Cropland
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Cover Crop

Rule Definition

“Cover Crop” means plants or a green manure crop grown for seasonal soil protection or soil improvement.

Purpose

Cover crops help control soil movement and protect the soil surface between crops. Cover crop reduces wind erosion 

by shielding the soil with vegetation and anchoring the soil with roots.

Suggestions for Implementation

It is recommended that:

Cover crops consist of any vegetative cover that maintains more than 

60 percent ground cover.

Short-term cover be grown between major crops. Plants are then tilled 

into the soil prior to or during major crop planting.

Longer-term cover may be maintained by periodic mowing to maintain 

at least 60 percent cover.

Specific information on cover crops can be obtained from the 

Cooperative Extension Service or the NRCD office.

Cross-Wind Ridges

Rule Definition

“Cross-Wind Ridges” means soil ridges formed by a tillage operation.

Purpose

Ridges formed by tillage operations create protective windbreaks that disrupt the erosive forces of high winds.

Suggestions for Implementation

It is recommended that:

Ridges formed by tillage or planting should be aligned across the prevailing wind direction.

While 90 degrees or perpendicular is preferred, benefits can still be realized with ridges as close to perpendicular 

as possible.

If ridges deteriorate and become ineffective due to weathering or erosion, they should be reestablished, unless 

doing so would damage a growing crop.

This practice is best adapted on soils, which are stable enough to sustain effective ridges, such as clayey, silty 

and sandy loam soils. It is not well adapted on unstable soils, such as sands, loamy sands and certain organic 

soils. 

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Cross-Wind Strip-Cropping

Rule Definition

“Cross-Wind Strip-Cropping” means planting strips of alternating crops within the same field.

Purpose

Growing crops or managing residue as a protective cover in strips across the prevailing wind direction can break the 

effects of high wind events.

Suggestions for Implementation

It is recommended that:

Cross-wind strip-cropping system consists of at least two crop or residue cover alternating strips.

Strip widths should be at least 25 feet but no more than 330 feet.

Strips should be aligned across the prevailing wind direction. While 90 degrees or perpendicular is preferred, 

benefits can still be realized when the strips are oriented as close to perpendicular as possible.

Protective cover includes, but is not limited to a growing crop, grasses, legumes, grass-legume mixtures, 

standing stubble or tilled residue with enough surface cover to provide protection.

Cross-Wind Vegetative Strips

Rule Definition

“Cross-Wind Vegetative Strips” means herbaceous cover established in 1 or more strips within the same field.

Purpose

Herbaceous cover creates a protective windbreak that disrupts the erosive forces of high winds, especially during 

critical wind erosion periods.

Suggestions for Implementation

It is recommended that:

Herbaceous cover should be composed of perennial or annual vegetation, growing or dead.

Strips consist of at least one row of plants, providing the porosity can be achieved with a single row that contains 

no gaps.

When two or more rows are required to achieve the required porosity and to avoid gaps, the rows should be 

spaced no more than 36 inches apart.

Annual vegetation strips be composed of more than one row.

Strips designed for this purpose have a minimum expected height of two feet.

Strips designed for this purpose achieve a minimum porosity of 40 to 50 percent.

Spacing between strips (not within row) not exceed 12 times the expected height of the herbaceous cover.

Spacing between strips be adjusted to accommodate widths of farm equipment to minimize partial or incomplete 

passes.

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Integrated Pest Management

Rule Definition

“Integrated Pest Management” means the use of a combination of techniques including organic, conventional and 

biological farming practices.

Purpose

Integrated pest management creates beneficial insect habitat that reduces 

the use of herbicides/ pesticides, thereby reducing the number of passes for 

spraying. It also reduces soil compaction and the need for additional tillage.

Examples of Integrated Pest Management

Monitoring crop for pests to accurately and effectively apply control 

measures.

Incorporate biological practices into farming operation to reduce need for 

spraying.

Manure Application

Rule Definition

“Manure Application” means applying animal waste or biosolids to a soil surface.

Purpose

Applying manure to maintain or improve chemical and biological condition of the soil can help reduce wind erosion 

and PM10.

Suggestions for Implementation

• If the application or storage of manure is near a water source, precautions should be taken to prevent accidental

leakage, spillage or runoff that will result in undesirable effects on soil, water and plants.

• Caution should be used when applying manure to ensure that state and local regulations are not violated.

• Caution should be used when certain manures are applied as they can volatilize and contribute to odor and 

ammonia emissions.

• Manures should be incorporated as quickly as possible to reduce odor and ammonia emissions, and to preserve 

nutrient value if the area is to be cropped in the future.

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Mulching

Rule Definition

“Mulching” means applying plant residue or other material that is not produced on site to a soil surface.

Purpose

Adding a protective layer to the soil surface reduces soil movement in high wind events.

This practice also conserves soil moisture, which can reduce surface movement of soil.

Suggestions for Implementation

It is recommended that:

• This practice can be used after low residue producing crops, like cotton, are harvested.

• Materials for mulching are acquired as waste products from other enterprises.

• These include, but are not limited to, wood bark, chips, shavings, and saw dust; food processing wastes; and 

small grain straw/chaff.

• Mulches are applied by blowers, hydro applicators, disk type straw punchers and spreaders.

• When small grain straw is used, spread at least 4,000 pounds straw per acre, distribute evenly and partially 

incorporate into the soil.

• When wood fibers are used, spread at least 2,000 pounds per acre or achieve 80 percent cover.

Multi-Year Crop

Rule Definition

“Multi-Year Crop” means a crop, pasture, or orchard that is grown, or will be grown, on a continuous basis for more 

than one year.

Purpose

Surface covers, such as crops, pasture and orchards, that are grown and maintained for a long duration, protect the 

soil surface from erosive winds. The longer a crop or cover is protecting the soil surface, the less time the surface is 

susceptible to wind erosion.

Examples of Multi-Year Crops are:

• Alfalfa

• Citrus

• Roses

• Livestock pastures

• Nuts (Pecans)

• Sod
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Permanent Cover

Rule Definition

“Permanent Cover” means a perennial vegetative cover on cropland.

Purpose

Maintaining a long-term (perennial) vegetative cover on cropland that is temporarily not producing a major crop 

protects the soil surface from erosive winds.

Suggestions for Implementation

It is recommended that:

Perennial species of grasses and/or legumes be used to establish at least 60 percent cover.

When perennial species are used, maintenance by periodic mowing or swathing/baling is encouraged.

Specific information on permanent cover types can be obtained from the Cooperative Extension Service or all 

NRCD offices.

Planting Based on Soil Moisture

Rule Definition

“Planting Based on Soil Moisture” means applying water to soil before performing planting operations.

Purpose

Planting based on soil moisture reduces PM10 during the planting operation and is effective from the time of 

planting until crop establishment. Planting based on soil moisture is one of the most efficient practices to reduce 

PM10 between planting and crop emergence. Moisture causes soil to crust and therefore PM10 is not easily 

transported into the air.

Suggestions for Implementation

Care should be taken to avoid over compaction of the soil, which could result in additional tillage operations.

Irrigation should be applied as soon after soil preparation for planting as possible. After watering, a thin crust 

develops on the soil surface, which stabilizes the soil until planting

The time between bed lifting, irrigation and planting should be minimized as much as possible.

Use the soil moisture “feel method” to determine adequate soil moisture. See the Natural Resource Conservation 

Service publication #1619 “Estimating Soil Moisture by Feel and Appearance.” This publication is available at 

all NRCD offices.

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Residue Management

Rule Definition

“Residue Management” means managing the amount and distribution of crop and other plant residues on a soil 

surface.

Purpose

Leaving crop and other plant residues on the soil surface can protect the soil between the time of harvest of one crop 

and emergence of a new crop, thus helping reduce wind erosion and the generation of PM10.

Suggestions for Implementation

Many different residue management systems have been developed. Some examples include:

Reduced tillage systems, such as mulch-till, which partially incorporate surface residues and involve no plowing.

No-till, this involves planting directly into the soil without any alteration to the seedbed. One example is planting 

a new crop directly into the grain stubble.

Soil protection by crop residues can be increased by leaving residues on the soil surface as long as possible (e.g. 

by delaying tillage operations until just before planting).

It is recommended that:

Stubble be left standing at six inches or more.

Tillage be limited during this period to undercutting tools, such as 

blades, sweeps or deep tillage implements, such as a ripper or subsoiler.

Loose residue be uniformly distributed on the soil surface.

Residues from previous crops be left to maintain 60 percent ground 

cover.

Specific information on determining small grain residue equivalents 

can be obtained from the Cooperative Extension Service or all NRCD 

offices. 

Consult NRCS Standard and Specification for Residue Management, # 329 and 344. This document is available 

at all NRCD offices.

Sequential Cropping

Rule Definition

“Sequential Cropping” means growing crops in a sequence that minimizes the amount of time bare soil is exposed 

on a field.

Purpose

By reducing the amount of time bare soil is exposed, sequential cropping helps reduce the window of time that the 

cropland is susceptible to PM10 erosion.

Some examples of sequential cropping include:

Planting a winter grain crop between final harvest of a cotton crop and the planting of the next cotton crop.

Close rotations of vegetable crops.

Suggestions for Implementation

It is recommended that:

The amount of time bare soil is exposed be limited to 30 days or less.

Rotations be provided for acceptable substitute crops in case of crop failure or shift in planting intentions for 

weather related or economic reasons.

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Surface Roughening

Rule Definition

“Surface Roughening” means manipulating a soil surface to produce or maintain clods.

Purpose

The formation of clods helps disrupt the erosive force of the wind over an unprotected soil surface. Soil clods can be 

formed by tillage implements under appropriate soil moisture conditions.

Suggestions for Implementation

Not all soils are able to form clods. Review the local soil survey or 

contact the NRCD office to help determine a specific field’s soil type.

Caution should be used to determine the most opportune time to 

roughen the soil surface while considering the tillage needed prior to 

planting, crop to be grown and irrigation water management needs 

(surface roughening can dry the upper soil profile more rapidly than 

not disturbing the soil).

Transgenic Crops

Rule Definition

“Transgenic Crops” means the use of plants that are genetically modified. 

Purpose

Transgenic crops reduce the need for tillage or cultivation operations, as well as reduces soil disturbance. Can also 

reduce the number of chemical applications.

Examples of Transgenic Crops

Genetically altered seed

Nematode resistant rootstock

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Tree, Shrub, or Windbreak Planting

Rule Definition

“Tree, Shrub, or Windbreak planting” means providing a woody vegetative barrier to the wind.

Purpose

Barriers placed perpendicular to the wind direction can reduce wind speeds by changing the pattern of airflow over 

the land surface, which helps to reduce wind erosion and PM10.

Suggestions for Implementation

The distance of 10 times the barrier height is considered the protected area downwind of the barrier.

Single row plantings are most popular in field windbreaks because they use less water and occupy the least 

amount of land area for the amount of protection derived.

Recommended species for planting can be obtained at all NRCD offices.

The planting should be done at a time and manner to insure survival and growth of selected species.

Moisture conservation or supplemental watering should be provided for plant establishment and growth, as well 

as the use of drought tolerant species.

Windbreaks should be aligned across the prevailing wind direction. While 90 degrees or perpendicular is 

preferred, benefits can still be realized when windbreaks are aligned as close to perpendicular as possible.

The interval between windbreaks should be determined using current approved wind erosion technology 

available at all NRCD offices.

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Agricultural Best Management Practices General Permit Record

The following is an example of a form that you can use or duplicate. You are not required to use this form.Name of commercial farmer________________________________________ Date_________________________Mailing or physical address of the commercial farm_______________________________________________________________ Phone_______________________________________________________________________________________ City____________________________State________Zip_________________ Email________________________

Selected Best Management Practices. A commercial farmer must implement at least TWO practices from each category.

CATEGORY I: Tillage

& Harvest

□	 Cessation of Night Tilling□	 Chemical Irrigation □	 Combining Tractor Operations□	 Equipment Modification □	 Green Chop□	 Integrated Pest Management □	 Limited Activity during High-wind Events□	 Multi-year Crop□	 Planting Based on Soil Moisture □	 Precision Farming □	 Reduced Harvest Activity □	 Reduced Tillage System□	 Tillage Based on Soil Moisture□	 Timing of Tillage Operation□	 Transgenic CropsNotes:

CATEGORY II: Non-Cropland□	 Access Restriction □	 Aggregate Cover □	 Artificial Wind-barrier□	 Critical Area Planting □	 Manure Application□	 Reduce Vehicle Speed□	 Synthetic Particulate Suppressant□	 Track-out Control System□	 Tree/Shrub/Windbreak Planting□	 WateringNotes:

CATEGORY III: Cropland□	 Artificial Wind-barrier□	 Cover Crop□	 Cross-wind Ridges□	 Cross-wind Strip-cropping□	 Cross-wind Vegetative Strip□	 Integrated Pest Management□	 Manure Application□	 Mulching□	 Multi-year Crop□	 Permanent cover□	 Planting Based on Soil Moisture□	 Residue Management□	 Sequential Cropping□	 Surface Roughening□	 Transgenic Crops□	 Tree/Shrub/Windbreak PlantingNotes:

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Signature:___________________________________________________________
Stakeholders and Collaborating Partners

Arizona Cotton Growers Association

Arizona Department of Agriculture

Arizona Department of Environmental Quality

Arizona Farm Bureau Federation

Arizona Nursery Association

Maricopa Association of Governments

Maricopa County Air Quality Department

Maricopa County Farm Bureau

Natural Resource Conservation Districts

USDA Agricultural Research Service

USDA Natural Resources Conservation Service

US Environmental Protection Agency Region IX

University of Arizona - College of Agriculture and Life Sciences

University of Arizona - Cooperative Extension, Maricopa County

Western Growers Association




APPENDIX D 

Public Process 
The Arizona Department of Environmental Quality (ADEQ) will hold a public hearing to receive 

comments on a proposed revision to the 2001 Agricultural Best Management Practices – Maricopa 

County PM10 Serious Area State Implementation Plan (SIP). In 2007, the Governor’s Agricultural 

Best Management Practices Committee adopted new best management practices (BMPs) to the 

existing list of BMPs. The Arizona Legislature also passed Senate Bill 1552, which doubled the 

required BMPs per category of agricultural activities and extended the area of application of BMPs. 

State rules already reflect these changes. ADEQ will submit a revised SIP to the U.S. 

Environmental Protection Agency (EPA) to reflect the legislative and rule changes. 

PUBLIC COMMENT AND HEARING NOTICE 

ARIZONA DEPARTMENT OF ENVIRONMENTAL QUALITY 

AIR QUALITY DIVISION 

PUBLIC HEARING ON PROPOSED AGRICULTURAL BEST MANAGEMENT 

PRACTICES - MARICOPA COUNTY PM10 SERIOUS AREA 

STATE IMPLEMENTATION PLAN REVISION 

The public hearing on the proposed plan will be held at 3:00 p.m. on Wednesday, October 28, 2009, 

at the Arizona Department of Environmental Quality, 1110 West Washington Street, Phoenix, in 

conference room 145. All interested parties will be given an opportunity at the public hearing to 

submit relevant comments, data, and views, orally and in writing. 

The public comment period for the proposed SIP revision will end upon the closure of this public 

hearing or at 5:00 p.m. on Wednesday, October 28, 2009, whichever is later. Comments postmarked 

on or before that date will be accepted. Comments should be addressed, faxed, or e-mailed to:

Lisa Tomczak 

Air Quality Planning Section 

Arizona Department of Environmental Quality 

1110 W. Washington Street 

Phoenix, AZ 85007 

FAX: (602) 771-2366 

E-Mail: tomczak.lisa@azdeq.gov

The draft report is also available for review at the location below. 

Arizona Department of Environmental Quality 

First Floor Library 

1110 W. Washington Street 

Phoenix, Arizona 85007 

Lorraine Cona, (602) 771-4335 


Public Hearing Agenda 

Printed on recycled paper 

AIR QUALITY DIVISION

Proposed Maricopa County PM10 Serious Area 

State Implementation Plan Revision 

Agricultural Best Management Practices 

Arizona Department of Environmental Quality 

1110 W. Washington Street, Phoenix, Arizona; Conference Room 145 

3:00 p.m.; Wednesday, October 28, 2009 

Pursuant to 40 CFR § 51.102 notice is hereby given that the above referenced meeting is open to the 

public. 

1. Welcome and Introductions 

2. Purposes of the Oral Proceeding 

3. Procedure for Making Public Comment 

4. Brief Overview of the proposed SIP revision 

5. Question and Answer Period 

6. Oral Comment Period 

7. Adjournment of Oral Proceeding 

Copies of the proposal are available for review at the Arizona Department of Environmental Quality 

(ADEQ) Library, 1110 W. Washington St., Phoenix, Arizona. For additional information regarding the 

hearing please call Lisa Tomczak, ADEQ Air Quality Division, at (602) 771-4450 or 1-800-234-5677, 

Ext. 771-4450. 

Persons with a disability may request a reasonable accommodation, such as a sign language interpreter, by 

contacting Dan Flukas at (602) 771-4795 or 1-800-234-5677, Ext. 771-4795. Requests should be made as 

early as possible to allow sufficient time to make the arrangements for the accommodation. This 

document is available in alternative formats by contacting ADEQ TDD phone number at (602) 771-4829. 



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PROPOSED 2009 REVISION MARICOPA COUNTY PM10 SERIOUS 

AREA AGRICULTURAL BEST MANAGEMENT PRACTICES 

STATE IMPLEMENTATION PLAN 

Oral Proceeding 

Hearing Officer Script 

October 28, 2009 

Wendy Flood: Good afternoon and thank you for coming. I now open this public hearing to receive 

comments on the proposed 2009 Revised, Revision for the Maricopa County PM10 Serious Area – 

Agricultural Best Management Practices State Implementation Plan (SIP) (from this point on, 

AgBMP SIP Revision). 

It is now Wednesday, October 28, 2009. The location is Room 145, Arizona Department of 

Environmental Quality, Phoenix, Arizona. My name is Wendy Flood and I have been appointed by 

the Director of the Arizona Department of Environmental Quality to preside at this proceeding. 

The purposes of this proceeding are to provide the public an opportunity to: 

1) hear about the substance of the proposed AgBMP SIP, 

Corky Martinkovic: AgBMP 

Wendy: I’m sorry, what? 

Corky: AgBMP 

Wendy: AgBMP, excuse me. SIP 

2) ask questions regarding the proposed AgBMP SIP, and 
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1 3) present oral argument, data, and views regarding the proposed AgBMP SIP in the form of 

comments on the record. 

Lisa Tomczak is here representing the ADEQ Air Quality Planning Section. Will other ADEQ 

employees please introduce themselves? 

Ira Domsky: Ira Domsky, Deputy Director, Air Quality Division. 

Emily Bonanni: Emily Bonanni, Air Quality Compliance. 

Corky Martinkovic: Corky Martinkovic, Air Quality Planning. 

Steven Peplau: Steven Peplau, Assessment. 

Diane Arnst: Diane Arnst, Planning Section Manager. 

Viviene Burns: Viviene Burns, Water Quality Division, Compliance and Enforcement. 

The proposed AgBMP SIP was released for public comment on September 21, 2009. The notices 

appeared in the Arizona Republic and the ADEQ website. 

The procedure for making a public comment on the record is straightforward. If you wish to 

comment, you need to fill out a speaker slip, which is available at the sign-in table, and give it to me. 

Using speaker slips allows everyone an opportunity to be heard and allows us to match the name on 

the official record with the comments. 

You may also submit written comments to me here today. Please note, the comment period on 

proposed AgBMP SIP closes at the completion of this public hearing or 5:00 p.m. today, whichever 

is later. 
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The agenda for this hearing is simple. First, we will present a brief overview of the proposed 

AgBMP SIP. Next, I will conduct a question and answer period. The purpose of the question and 

answer period is to provide information that may help you in making comments on the revision to 

the proposed AgBMP SIP. Thirdly, I will conduct the oral comment period. At that time, I will 

begin to call speakers in the order that I have received speaker slips. 

Please be aware that any comments you make at today's hearing that you, please be aware that any 

comments you make at today's hearing that you want the Department to formally consider must be 

given either in writing or on the record during the oral comment period of this proceeding. 

* * * * * 

At this time, Lisa will give a brief overview of the AgBMP SIP Revision. 

Lisa: As detailed in the AgBMP SIP revision, the Maricopa County PM10 Serious 

Nonattainment Area has a long and complex regulatory history. On December 31, 2006, 

the nonattainment area failed to attain the PM10 NAAQS. Because of the failure to attain, 

the Clean Air Act requires that emissions in the PM10 nonattainment area be reduced by 5 

percent each year until the PM10 standard is attained. This requirement prompted the 

Governor’s Agricultural Best Management Prac (cough), Best Management Practices 

Committee to research and evaluate options to further reduce PM10 emissions from 

agricultural activities. 

The proposed AgBMP SIP revision contains a description of the new five BMPs, a 

description of the expanded area of application of the BMP program to include the 

Maricopa County portions of the PM10 nonattainment area, and a description of the new 

requirements for the number of BMPs required per agricultural category. A brief description 

of public outreach activities is also included in this SIP. The new BMPs adopted by the 

Committee were selected based on feasibility and efficacy for the farming community in the 

nonattainment area. The new BMPs include cessation of night tillage on high pollution 
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advisory days, green chop, integrated pest management, precision farming, and transgenic 

crops. Senate Bill 1552, passed by the Arizona Legislature in 2007, expanded the area of 

application of BMPs to include the Maricopa County portions of Area A and required two 

BMPs rather than one BMP to be implemented per agricultural category. 

The new BMPs and the requirements of SB 1552 are reflected in revisions to Arizona 

Administrative Code R18-2-610 and 611. The rules were developed as an exempt rule in 

order to be included in the Maricopa Association of Governments 2007 Five Percent Plan 

for PM-10 for the Maricopa County Nonattainment Area, submitted by ADEQ to EPA on 

December 31, December 21, 2007. This SIP revision updates the Maricopa County PM10

Serious Area SIP for Agricultural Best Management Practices, originally submitted to EPA 

by ADEQ in June 2001. 

This concludes the explanation period of the proceeding on the proposed AgBMP SIP. 

* * * * * 

Are there any questions before we move to the oral comment period? 

* * * * * 

I now open this proceeding for oral comments. 

I do have three speaker slips. Read the whole slip, right? Rick Lavis, representing Arizona Cotton 

Growers Association. Do you wish to make oral statement? 

Rick Lavis: I do Madam Chairman. 

Wendy: Okay. 

Rick: Thank you. I appreciate the opportunity to (microphone falls down) 
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So much for having my own microphone. (laughter) 

Rick: In concluding my 35 minute remarks. (laughter) Madam Chairman, thank you very much for 

the opportunity to comment on the submission of this proposed SIP to EPA. Since this is basically 

an agricultural submission, I am just going to make a few comments. 

This program has been in place for almost 13 years. When Agriculture was asked to participate in 

the 1998 effort, we were 13% of the problem, and we agreed to develop on our own, a Best 

Management Practices program, which included three categories. In each category, we were only 

supposed to choose one BMP to utilize as his contribution to the reduction of PM10 emissions in the 

nonattainment area. 

As you well know, and as your statement in advance indicated, EPA in 2007 said you are not doing 

enough. So everybody who was involved in the PM10 nonattainment area would have to do more. 

Agriculture responded by a number of things they did. (1) They evaluated all the existing BMPs that 

they had in place to determine their efficacy and effectiveness. They decided to add five additional 

BMPs, AgBMPs, to that list, which I find in your statement. In addition to that, we agreed to require 

the grower to choose two events from each category, instead of just one. In addition, the Department 

of Environmental Quality asked us to consider the expansion of the AgBMP program to what is 

know as Area A. Although not officially nonattainment, it is certainly a part of the overall area 

quality shed that the Department is concerned about. 

We talked among ourselves for a long period of time and then agreed to expand the BMP program to 

Area A in Maricopa County only, because certainly a part of that part A, or Area A (?). So, in 

respect to those decisions, we are, have concluded that the tons reduction was approximately, I 

believe, 540 tons, which would be added to that amount require to meet 5% of our goal for the 

submission to EPA. 

There has been some issue, not an issue, but a question about our educational effort or outreach. I 

would like to comment on the fact that the, Jeannette Fish and the Maricopa County Farm Bureau, as 
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a part of the Ag coalition, put together a program to find outreach to all our growers in the 

nonattainment area, and I will let her speak to that. 

In addition, we did publish a second brochure, which is here, and it was a follow-up to the original 

brochure that was issued in 1997 or 1998, when we first got into this program. This, we published 

approximately 2700 copies of this brochure, and it was sent to approximately 1800 growers in the 

county, nonattainment area. It was an effort to make sure that everyone was aware and understood 

what the new rules were. 

Now, we believe that we are contributing (?) to this effort, and we will continue to do so in every 

way we can to be a partner in the effort to reduce PM10 emissions in this nonattainment area and 

attempt to also reach attainment. 

With that, Madam Chairman, thank you very much for allowing me to participate. If you have any 

questions, I certainly will be happy to answer them. 

Wendy: Seeing no questions for Mr. Lavis, we will move to the next speaker slip. Ms. Jeannette Fish 

of the Maricopa County Farm Bureau, do you wish to make an oral statement? 

Jeannette Fish: Yes, I do. Thank you. Before I do, I need to ask Mr. Lavis, since he handed over to 

me the piece of the report which I wrote for him and didn’t bring my own piece of it. Could I please 

have that sheet of paper, Mr. Lavis? 

Rick: Yeah. 

Jeannette: Thank you. Good afternoon, my name is Jeannette Fish. I am the Executive Director of 

the Maricopa County Farm Bureau. We have approximately 900 agricultural members of our 

organization within the boundaries of Maricopa County. My comments will be very short. First of 

all, I would like to touch on what Mr. Lavis referred to, and that was the educational outreach. In 

2008, we held two meetings in the month of May and invited everyone who belongs to Farm Bureau, 

the Nursery Association and the Cotton Growers Association, to attend those meetings. One was 
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held on May 10th on the West side, at Estrella Mountain Community College. We counted 55 people 

in attendance. On the 22nd of May, we held one on the East side, at the Arizona Farm Bureau offices. 

There were 29 people by my count who were, who attended that one. These people, of course, would 

have passed that information as they went back to their homes. That program included an overview 

of the Best Management Practices Program, why we needed to do more, a presentation on what the 

ADEQ inspector does, an update on what was going on with the County rules at that time, which I 

did a PowerPoint presentation then from Rusty Van Leuven, of the Agricultural Consultation and 

Training Program at the Department of Agriculture on how he could assist them in complying with 

these new requirements and then wrap up on what needs to be done by you. In other words, the 

farmers. That was done by Kevin Rogers and Dan Thelander. 

In addition, the various agricultural organizations printed articles in their publications over the space 

of 2007 and 2008. I know my own little newsletter had something about complying with dust 

regulations in every issue in both years of 2007 and 2008. In fact, I think that my members are 

getting really tired of hearing from me about that. 

In addition, the remainder of my comments are that we, agriculture, under the new SIP, has doubled 

its requirement for the people involved in road crop farming in this county. We’ve extended the area 

where Best Management Practices must be utilized, specifically to the west and the southwest parts 

of the county. In turn, that therefore expands the number of farms and farmers that are involved in 

the Best Management Practices Program. We added additional Best Management Practices as Lisa 

outlined in her overview, and yet with doing all of this, we managed to do it by meeting the statutory 

requirements to be effective in reducing PM10 that may be generated by agricultural operations and 

be economically feasible for the farmers to adopt. 

Thank you for the opportunity to comment, and I would be happy to answer any questions. 

Wendy: Seeing no questions, the next speaker slip is Mr. Joseph Sigg from the Arizona Farm 

Bureau. Do you wish to make oral comment? 
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Joseph Sigg: Yes, I do, Madam Chairman. My name is Joseph Sigg. I represent the Arizona Farm 

Bureau. I will not be repetitious. I accept and support the comments that Mr. Lavis and Ms. Fish 

have already said. Obviously, we do support the proposition. I want to make that very clear. 

Agriculture continues to be a part of this process in a cooperative way, and we expect to in the 

future. I will be glad to entertain any questions. Thank you. 

Wendy: Okay. Seeing no questions, the next speaker is Mr. Robert Shuler from the Western 

Growers Association. Do you wish to make oral statement? 

Robert Shuler: I do. My name is Robert Shuler. I do represent Western Growers Association. As the 

previous speakers have said, I too support the comments that have been made by them. We also as 

an organization support the revised AgBMPs as well as the proposed statewide, or State 

Implementation Plan revisions. With that, I will answer any questions. 

Wendy: Okay. Seeing there are no more questions and having no further speaker slips, this 

concludes the oral comment period of the proceeding. 

* * * * * 

If you have not already submitted written comments, you may submit them to me at this time. 

Again, the comment period for this draft report closes at 5:00 p.m. on Wednesday, October 28, 2009. 

I have not received any written comments. All speakers have spoken, so thank you for attending. 

The time is now 3:27, and I now close this oral proceeding. 
RESPONSIVENESS SUMMARY 

to 

Oral Comments Taken at the Public Hearing and Written Comments Received on the 

Proposed Agricultural Best Management Practices State Implementation Plan Revision 

The public hearing on the Proposed Agricultural Best Management Practices State Implementation Plan 

Revision was held on Wednesday, October 28, 2009, at the Arizona Department of Environmental 

Quality (ADEQ), conference room 145, 1110 West Washington Street, Phoenix, Arizona. Four oral 

comments were received during the hearing. ADEQ received six written comment during the public 

comment period, which ended October 28, 2009. The public comments and ADEQ’s responses are 

described below. 

Comment 1: 

In Chapter 3.0, Section 3.1, please provide references for the emission reductions that are cited for each of 

the five BMPs. 

ADEQ Response: 

References to the Appendix, “Agricultural Best Management Practices Technical Support Document” 

will be added to the Agricultural Best Management Practices State Implementation Plan. This technical 

support document describes the calculation of the emission reductions for the five BMPs. 

Comment 2: 

In Chapter 3.0, Section 3.2, Emission Reductions from Revision to the BMP Program: It is not clear why 

there is so much emphasize on the “Cessation of Night Tilling” BMP. This is one of five additional 

BMPs being added to the list of options but it is the only BMP specifically discussed in Section 3.2. 

ADEQ Response: 

The Cessation of Night Tilling BMP was discussed in more detail than the other BMPs because PM10

emissions generated from night tilling have the potential to sharply increase PM10 concentrations due to 

strong nighttime inversions trapping these emissions relatively close to the ground. 

Comment 3: 

In Appendix A, Agricultural Best Management Practices Rule: the last page of the rule is missing. 

ADEQ Response: 

ADEQ will submit the full rule with the final submission to EPA. 

Comment 4: 

In Appendix B, Technical Support Document, page 14, first paragraph: the second sentence appears to be 

incorrect. The sentence states that “The ‘harvested acres of field crops’, rate of change factor was used to 

develop projected uncontrolled and controlled emissions for Tillage & Harvest BMPs and Noncropland/Unpaved Farm Roads BMPs, while the ‘harvested acres of all crops’ rate of change factor was 

used to develop projected emissions for the Cropland/Windblown Agriculture BMPs.” However, in 

reviewing the calculations it appears that “Harvested acres of all crops” was used to calculate Noncropland/Unpaved Farm Roads emissions and “Harvested Acres of Field Crops (2003 as base year)” was 

used to calculate “Cropland/Windblown emissions”. 
ADEQ Response: 

The second sentence was incorrect. It will be revised to read: The “Harvested Acres of Field Crops” rate 

of change factor was used to develop projected uncontrolled and controlled emissions for the Tillage & 

Harvest BMPs, the “Harvested Acres of All Crops” rate of change factor was used to develop projected 

uncontrolled and controlled emissions for the Non-cropland / Unpaved Farm Roads BMPs, and the 

“Harvested Acres of Field Crops (base year 2003)” rate of change factor was used to develop projected 

uncontrolled and controlled emissions for the Cropland/Windblown Agriculture BMPs. 

Comment 5: 

In Appendix B, Technical Support Document, page 14, first paragraph: please explain why a 2005 base 

year rate of change factor for “Harvested Acres of Field Crops” is being used for “Tillage & Harvest 

BMPs” and a 2003 base year rate of change factor for “Harvested Acres of Field Crops” is being used for 

“Cropland/Windblown emissions”. 

ADEQ Response: 

The methodology for calculating windblown dust emissions in the MAG 2007 Five Percent Plan 

(documented in the TSD, Appendix II, Exhibit 3 in Appendices Volume Four) averages wind and activity 

data for the years 2001-2005. Since 2003 was the midpoint year of this analysis, 2003 was chosen as the 

base year for calculating the growth factors for agricultural windblown dust emissions. 

Comment 6: 

In Appendix B, Technical Support Document: Attachment #1, Table A-1, page Attachment 24 & 25: 

The same Maricopa BMP control efficiency (42%) was used for all speed reduction control measures. 

The control efficiency for “reducing speed from 25.9 to 5 mph” could not possibly be the same as 

“reducing speed from 25.9 mph to 25”. The San Joaquin CMP control efficiencies vary based on the 

speed reduction with larger speed reductions resulting in higher the control efficiencies. 

ADEQ Response: 

Table A-1 was developed to compare Maricopa BMPs against the San Joaquin CMPs. Since the 

Maricopa BMP for speed reduction states that speeds should be reduced to 15 mph, and does not include 

speed reductions other than 15 mph, the same Maricopa BMP emission reduction, 42%, was listed for 

comparison with the other emission reductions listed for the San Joaquin speed reduction CMPs. 

However, since using the 42% emission reduction to compare to the San Joaquin CMP speed reductions 

other than 15 mph can be confusing, Table A-1 will be revised to remove the 42% emission reductions 

listed for these other speed reductions for the Maricopa BMPs.