San Joaquin Valley Unified Air Pollution Control District April 16, 2015 

Appendix H: Summary of Significant Comments and Responses 

2015 Plan for the 1997 PM2.5 Standard 

Appendix H

Summary	of	Significant	Comments	and	Responses	

2015 Plan for the 1997 PM2.5 Standard

SJVUAPCD	

 

 
San Joaquin Valley Unified Air Pollution Control District April 16, 2015 

Appendix H: Summary of Significant Comments and Responses 

2015 Plan for the 1997 PM2.5 Standard 

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San Joaquin Valley Unified Air Pollution Control District April 16, 2015 

H-1 Appendix H: Summary of Significant Comments and Responses 

2015 Plan for the 1997 PM2.5 Standard 

SUMMARY OF SIGNIFICANT COMMENTS 

MARCH 17, 2015 PROPOSED 2015 PLAN FOR THE 1997 PM2.5 

STANDARD 

EPA REGION IX COMMENTS: 

No comments were received from EPA. 

ARB COMMENTS: 

No comments were received from ARB. 

PUBLIC COMMENTS: 

No comments were received from the public. 
San Joaquin Valley Unified Air Pollution Control District April 16, 2015 

H-2 Appendix H: Summary of Significant Comments and Responses 

2015 Plan for the 1997 PM2.5 Standard 

SUMMARY OF SIGNIFICANT COMMENTS 

MARCH 4, 2015 DRAFT 2015 PLAN FOR THE 1997 PM2.5 STANDARD 

EPA REGION IX COMMENTS: 

No comments were received from EPA. 

ARB COMMENTS: 

No comments were received from ARB. 

PUBLIC COMMENTS: 

Comments were received from the following: 

Agricultural Producers and Processors (APP)1 

Central California Environmental Justice Network (CCEJN) 

Central Valley Air Quality Coalition (CVAQ) 

City of Fresno Planning (COF) 

Dairy Cares (DC)2

Medical Advocates for Healthy Air (MAHA) 

Sandra Brock (Brock) 

Southern California Gas Company (SCGC) 

1. COMMENT: Will GAMAQI be updated to reflect the change in the definition of a 

major source for PM2.5 from 100 tons per year (tpy) to 70 tpy for NSR level? 

(COF)

RESPONSE: The GAMAQI does not refer to any major source definition or 

thresholds for NSR. Therefore, revisions to the GAMAQI are not necessary. 

 

1

 Agricultural Producers and Processers: Comments were submitted on behalf of the following agricultural agencies, 

representing agricultural producers and processors throughout the Valley: African American Farmers of California, 

California Blueberry Association, California Citrus Mutual, California Cotton Ginners Association, California Cotton 

Growers Association, California Farm Bureau Federation, California Fresh Fruit Association, Corcoran Irrigation 

District, Fresno County Farm Bureau, Kings County Farm Bureau, Kern County Farm Bureau, Milk Producers 

Council, National Hmong American Farmers, Nisei Farmers League, Stanislaus County Farm Bureau, Tulare County 

Farm Bureau, Tulare Lake Basin Water Storage District, Tulare Lake Drainage District, Tulare Lake Resource 

Conservation District, Western Agricultural Processors Association, Western Growers Association, Delta Lands 

Reclamation District No. 770, El Rico Reclamation District No. 1618, Homeland Reclamation District No. 780, North 

Central Reclamation District No. 2071, South Central Reclamation District 2125, Tulare Lake Reclamation District 

749, Peoples Ditch Company, Last Chance Water Ditch Company, Tulare Lake Canal Company, Southeast Water 

Company

2

 Dairy Cares is a coalition of dairy and milk producer and processor organizations and cooperatives including: 

Western United Dairymen, California Dairy Campaign, Milk Producers Council, California Farm Bureau Federation, 

California Cattlemen’s Association, California Dairies, Inc., Dairy Farmers of America-Western Area Council, Hilmar 

Cheese Company, and Land O’Lakes, Inc.
San Joaquin Valley Unified Air Pollution Control District April 16, 2015 

H-3 Appendix H: Summary of Significant Comments and Responses 

2015 Plan for the 1997 PM2.5 Standard 

2. COMMENT: The District should consider offering incentives to lead agencies to 

implement subdivision ordinances that prohibit wood burning of any type and that 

prohibit the creation of more dirt roads. (Brock)

RESPONSE: The incentive programs operated by the District are typically

created under specific guidelines to ensure the emissions reductions achieved by 

these programs are cost-effective, enforceable, and quantifiable. Incentives for 

implementing ordinances to prohibit wood burning or dirt roads would be difficult 

to quantify and may not be cost-effective. Additionally, the District already 

regulates the installation of wood burning fireplaces and wood burning heaters 

through density requirements in Rule 4901, and implements wood burning 

curtailments during poor air quality episodes through the Check Before You Burn 

program. Similarly, District Rule 8061 already limits fugitive dust emissions from 

paved and unpaved roads by implementing control measures and design criteria. 

3. COMMENT: The claim that the Valley is NOx-limited is insufficiently supported. 

The District should revise the 2015 PM2.5 Plan to include ammonia controls 

because ammonia is a major precursor for PM2.5. (CVAQ, MAHA)

RESPONSE: The plan control strategy achieves the emissions necessary to

bring the Valley into attainment, primarily through PM2.5 and NOx emissions 

reductions. Most areas of the Valley will reach attainment well before 2020. The 

District’s incentive programs, public outreach, and other innovative strategies will 

help expedite air quality improvements as this plan is implemented. Although the 

plan shows expeditious attainment and includes a comprehensive control 

strategy for direct PM2.5 emissions and significant PM2.5 precursors, the District 

and ARB explored the effectiveness of ammonia reductions in reducing PM2.5 

concentrations. 

The review of extensive science on this subject and previous modeling 

conducted conclude that reducing ammonia emissions is orders of magnitude 

less effective in reducing PM2.5 concentrations than reducing directly emitted 

PM2.5 or NOx emissions. There is a relative abundance of ammonia compared 

to nitric acid, and the amount of nitric acid drives the ultimate formation of 

ammonium nitrate. Because of this regional surplus in ammonia, even 

substantial ammonia emissions reductions yield a relatively small reduction in 

nitrate. Reductions in nitrate concentrations of 30% to 50% were realized 

through a 50% reduction in NOx. Modeling a 50% reduction in ammonia, while 

unrealistic and not technologically achievable, would only realize less than 5% 

reductions in nitrate concentrations. 

Despite the fact that ammonia is an insignificant PM2.5 precursor in the 

Valley, the District evaluated current ammonia controls in Appendix C (BACM 

and MSM for Stationary and Area Sources) of this plan. The analyses show that 

the Valley’s ammonia emissions have been significantly reduced through 

stringent District regulations and current regulations implement BACM and MSM 
San Joaquin Valley Unified Air Pollution Control District April 16, 2015 

H-4 Appendix H: Summary of Significant Comments and Responses 

2015 Plan for the 1997 PM2.5 Standard 

in the Valley. The District has already reduced ammonia emissions from CAFs, 

the largest source of ammonia emissions under its jurisdiction, by over 100 tons 

per day through adoption of Rule 4570 (Confined Animal Facilities), the most 

stringent rule of its kind in the nation. The District did not find any additional 

feasible measures that could significantly reduce ammonia emissions.

4. COMMENT: Why has the District not achieved the same NOx reductions for this 

plan from stationary sources as ARB has achieved from mobile sources? 

(CCEJN)

RESPONSE: The District has implemented a comprehensive regulatory control 

strategy for over twenty years. Since 1992, the District has adopted over 600 

rules and amendments to implement this aggressive control strategy. Many 

current rules are fourth or fifth generation, meaning that they have been revised 

and emission limits have been lowered, as new emission control technology has 

become available and cost-effective. As a result of these extensive efforts and 

significant investments from Valley businesses, the emissions in the Valley from 

stationary sources have been reduced by 80% or more. 

ARB and EPA have regulatory authority over mobile sources of emissions in the 

Valley. As demonstrated in Figures 2-4 and 2-5 (see Chapter 2) the majority of 

the remaining emissions in the Valley are generated by mobile sources. In part 

due to the success of prohibitory rule efforts implemented by the District on 

stationary and area sources; in fact, mobile sources are now responsible for 85% 

of NOx emissions in the Valley (see Appendix B). 

5. COMMENT: Explain the difference between Best Available Control Measures 

(BACM) and Lowest Achievable Emissions Rate (LAER), and whether it is 

possible to implement LAER instead of BACM. (CCEJN)

RESPONSE: EPA defines BACM as the maximum degree of emissions 

reductions achievable from a source or source category, which is determined on 

a case-by-case basis considering energy, economic, and environmental impacts. 

LAER, on the other hand, is the most stringent emissions control that is 

technologically feasible and does not take into consideration any economic 

impacts or rather the cost effectiveness of a potential control measure. 

Within Appendix C of this plan, the District has examined every source category 

in the Valley for any potential opportunities for additional emissions reductions, 

which included reviewing LAER levels of control. However, since EPA’s 

definitions for BACM and Most Stringent Measures (MSM) state that air districts 

should account for the economic feasibility of all potential BACM or MSM, the 

District evaluated the cost effectiveness (in dollars per year, per ton of emissions 

reduced per year) of all technologically feasible control measures to determine if 
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H-5 Appendix H: Summary of Significant Comments and Responses 

2015 Plan for the 1997 PM2.5 Standard 

there were additional measures not already implemented in the District that 

qualify as BACM and/or MSM. 

Aside from this planning process, the District also evaluates LAER through the 

new source review (NSR) process, per District Rule 2201 (New and Modified 

Stationary Source Review Rule). Anytime there is a new or modified stationary 

source of air pollution, the respective source is required to implement Best 

Available Control Technology (BACT) levels of control for their new or modified 

equipment. To determine what qualifies as BACT, the District examines all 

LAER controls and then evaluates the cost effectiveness of the potential 

measure to see if it qualifies as BACT for that particular source. 

Given the high cost effectiveness of BACT/BACM controls, most air districts only 

enforce such stringent and costly requirements on new sources. However, due 

to the District’s unique air quality challenges, the District has enforced 

BACT/BACM levels of emissions controls on numerous retrofitted sources for 

years through these stringent permitting provisions and multi-generational rules. 

6. COMMENT: Provide more detail on the composition of ammonium, sodium, 

nitrate, etc., specifically for confined animal facilities (CAFs). Also, there are 

incentives for agricultural equipment, but when are agricultural equipment rules 

coming? (CVAQ)

RESPONSE: Information on the general composition of PM2.5 in the San 

Joaquin Valley can be found in Chapter 3 of the 2015 Plan for the 1997 PM2.5 

Standard. Figure 3-2 (page 3-12) of the plan shows the average annual 

compositions of PM2.5 in Fresno and Bakersfield. Recently, research has been 

undertaken to better characterize PM emissions from CAFs. The research 

available has indicated that the majority of directly emitted PM from CAFs is 

larger than PM2.5. In addition, most of directly emitted PM from CAFs is 

expected to occur in the dry summer months, rather than the winter months when 

the San Joaquin Valley has the highest concentrations of PM2.5. 

As discussed in the plan, ammonium nitrate and ammonium sulfate are not 

directly emitted, but rather are formed through secondary atmospheric reactions 

between precursors. As discussed in Chapter 2, Section 2.6 of the plan, 

because the formation of secondary ammonia particulate is limited by other 

precursors, ammonia is not a significant precursor to PM2.5 values in the San 

Joaquin Valley. Although ammonia is not a significant precursor to PM2.5 values 

in the Valley, the District has adopted stringent regulations that have reduced 

ammonia emissions (e.g. Rule 4565 - Biosolids, Animal Manure, and Poultry 

Litter Operations, Rule 4566 - Organic Material Composting, and Rule 4570 - and 

Confined Animal Facilities - Rule 4570). The District has already reduced 

ammonia emissions from CAFs, the largest source of ammonia emissions under 

its jurisdiction, by over 100 tons per day through adoption of Rule 4570 (Confined 

Animal Facilities), the most stringent rule of its kind in the nation. Please 
San Joaquin Valley Unified Air Pollution Control District April 16, 2015 

H-6 Appendix H: Summary of Significant Comments and Responses 

2015 Plan for the 1997 PM2.5 Standard 

reference Section C.41 (Ammonia Controls) in Appendix C of this plan for 

additional information. 

Lastly, ARB is currently undertaking a rule making process to regulate 

agricultural equipment, and the District is supportive of that effort. 

7. COMMENT: CNG engines are available that achieve greater emission 

reductions than the 2010 truck standards. The District should consider requiring 

greater reductions than those required in the 2010 truck standards by requiring or 

incentivizing the use of natural gas trucks. (SCG)

RESPONSE: The District is actively encouraging the continued development 

and certification of cleaner natural gas engines. Through the Technology 

Advancement Program, the District is partnering with an engine manufacturer for 

demonstration and durability testing of an advanced natural gas engine to be 

certified to an optional NOx standard which is 90% cleaner than the current 

engine standard. Additionally, the program is demonstrating natural gas/electric 

hybrid projects in both class 4 and class 7 trucks, highlighting the benefit of 

natural gas in those categories. The District is also considering additional 

methods to incentivize and encourage natural gas vehicles in the Valley. 

8. COMMENT: How do wildfires and controlled burns affect PM2.5 levels and

attainment of the federal standards? Also, what is the District’s involvement with 

agencies such as Bureaus of Land Management for large controlled burning? 

The District should do more outreach to rural areas for controlled burns. (COF)

RESPONSE: With the Valley being surrounded by mountain ranges, wildfires 

have the potential to have a significant impact on PM2.5 levels and subsequently 

affect the region’s ability to reach attainment of the federal PM2.5 standards. 

However, wildfires are considered “Exceptional Events” by EPA and outside of 

the control of the District. The recorded PM2.5 levels affected by these 

emissions can be removed from the regulatory data set used to determine 

compliance with the PM2.5 standards. This exceptional event process requires 

that extensive documentation be provided to EPA to support the event’s impact 

on the recorded values, showing that the high values would not have occurred 

“but for” the added emissions from the wildfire event. 

The emissions from controlled burns constitute a significantly smaller PM2.5 

fraction compared to wildfires, and usually have minimal and temporary impact 

on any nearby air quality monitors, if any. Controlled burns also play a critical 

role in reducing the fuel loading within these mountain ranges and help prevent 

catastrophic wildfires from potentially occurring. Controlled burning activities are 

regulated by the District under Rule 4106 (Prescribed Burning and Hazard 

Reduction Burning). 
San Joaquin Valley Unified Air Pollution Control District April 16, 2015 

H-7 Appendix H: Summary of Significant Comments and Responses 

2015 Plan for the 1997 PM2.5 Standard 

The District works in close coordination with the National Forest Service, the 

National Park Service, and other Land Management Agencies (LMAs) to 

strategically approve controlled burns only on days when air quality and 

atmospheric dispersion conditions are favorable. The District and LMAs also 

work together to minimize the potential smoke impacts to nearby communities 

from these burning activities. Through partnership with the District, the LMAs 

ensure that nearby communities are aware when a controlled burn is being 

planned for the area through the posting of information in public spaces, local 

publications, town hall meetings, electronic media, etc. The information shared 

assists the residents to plan appropriately while considering the potential 

temporary air quality impacts in the area. The District will continue to work 

closely with the LMAs in making sure that the public is made aware of future 

controlled burn projects in advance of their planned ignition. 

9. COMMENT: We support the District’s prioritization of control strategies that will 

result in the greatest human health benefits. We appreciate the District’s 

willingness to consider incentives for conservation tillage. We also support more 

natural gas trucks, especially if running on renewable natural gas such as can be 

generated with dairy manure. (DC)

RESPONSE: The District appreciates the comments above and will continue to 

evaluate potential control strategies under the District’s Health Risk Reduction 

Strategy. 

The District also supports efforts to reduce emissions through innovative 

approaches through its technology advancement program and through on-going 

research efforts. 

10. COMMENT: Rule 9510 (Indirect Source Review) was last updated in 2005; 

additional emissions could be reduced by expanding the rule’s applicability. The 

District should also eliminate the option for businesses to pay fees in lieu of 

mitigation measures and should require them to meet a minimum emissions level 

before paying fees. In addition, the District should increase the emissions 

reductions required for projects and add PM2.5 emissions limits. (CVAQ)

RESPONSE: Rule 9510 does not allow all project proponents to pay fees in lieu 

of mitigation requirements. The rule recognizes that while project design and 

CEQA mitigation requirements are land-use decisions that are outside the scope 

of the District’s direct regulatory authority, it is possible through the use of 

increased fees to encourage better project design, leading to lower emissions. 

In regards to the emissions reductions required for projects, Rule 9510 currently 

requires that all emissions above certain thresholds be mitigated through the 

District’s emission reduction incentive grant programs via the payment of fees to 

the District. Those fees are established at levels that the District demonstrates, 
San Joaquin Valley Unified Air Pollution Control District April 16, 2015 

H-8 Appendix H: Summary of Significant Comments and Responses 

2015 Plan for the 1997 PM2.5 Standard 

on an annual basis, to be sufficient to mitigate the full targeted emissions for 

projects subject to the rule. 

Lastly, adding a specific PM2.5 component to the rule would not result in reduced 

PM2.5 emissions because the rule already targets PM10 emissions. PM2.5 is a 

subset of PM10, and for combustion sources, PM10 is nearly 100% PM2.5. In 

fact, the sources of emissions reductions obtained through the District’s incentive 

programs are nearly 100% combustion sources, including both mobile and 

stationary sources. Therefore, by targeting PM10 sources, Rule 9510 also 

effectively addresses PM2.5 emissions. 

11. COMMENT: The District should revise Rule 4901 (Wood Burning Fireplaces and 

Wood Burning Heaters) to eliminate wood burning when the Valley is expected to 

exceed the 2006 PM2.5 NAAQS of 35 μg/m3. (CVAQ)

 

RESPONSE: Based on the latest amendments (September 2014), Rule 4901 is 

the most stringent wood burning curtailment rule in the nation. Residential woodburning with unregistered devices are no longer allowed when an area’s 

forecasted PM2.5 concentration is expected to be greater than or equal to 20 

μg/m3

 which comprise over 95% of wood burning emissions. This threshold is 

lower compared to past years when it was set at 30 μg/m3

. As such, this 

threshold is much lower than the 2006 and 2012 federal 24-hour average PM2.5 

standard of 35 μg/m3

. Allowing the cleanest wood burning heaters to be used 

between 20 and 65 μg/m3 provides significant motivation to Valley residents for 

transitioning away from older higher polluting devices to the cleanest wood 

burning heaters. A registered wood burning heater pollutes at least twenty times 

less than a wood burning fireplace; therefore, encouraging this transition reduces 

emissions beyond those that could be accomplished by only reducing the 

curtailment threshold to 20 μg/m3. The latest amendments to Rule 4901 will 

achieve an estimated reduction of 5.1 tons per day of PM2.5 emissions. 

12. COMMENT: The District should implement fleet rules for publicly-owned 

vehicles in the Valley. The District’s current fleet rule applies to school buses, 

but the SCAQMD fleet rules apply to buses, light-, medium-, and heavy-duty 

public fleet vehicles, airport ground transportation such as taxis and shuttles, and 

street sweepers. (CVAQ)

RESPONSE: Advancing the turnover of fleets is a critical component of reducing 

emissions. ARB has adopted fleet rules that have greatly reduced emissions 

from public fleet vehicles, and have superseded efforts at local levels to reduce 

emissions from those same fleets. The District also operates some of the most 

effective and robust vehicle grant programs in the nation, including a first of its 

kind rule to quantify emissions reductions from incentive programs for SIP 

creditability. The District will continue to look into opportunities for new fleet 
San Joaquin Valley Unified Air Pollution Control District April 16, 2015 

H-9 Appendix H: Summary of Significant Comments and Responses 

2015 Plan for the 1997 PM2.5 Standard 

rules, but at this time the District advances the turnover of fleets through the use 

of incentive funds. 

13. COMMENT: ARB should develop enforceable agricultural equipment regulations 

as soon as possible to accelerate attainment of the 1997 PM2.5 NAAQS in the 

Valley. (CVAQ)

RESPONSE: The District recognizes the need for additional emissions 

reductions from mobile agricultural equipment to address not only the 1997 

PM2.5 NAAQS, but the newer, more stringent federal 2006 PM2.5 NAAQS and 

2012 PM2.5 NAAQS. As such, the District will continue to work with ARB and 

the agricultural industry to develop regulations for mobile agricultural equipment 

(under ARB’s regulatory authority) to increase the use of the cleanest 

technologies as they become available in the San Joaquin Valley. 

14. COMMENT: The District Conservation Management Practices rule (Rule 4550) 

should be updated to reflect current practices, practices that overlap with other 

agency regulations should not be elective or be used to evidence rule 

compliance. Menu items regarding surface control in all agricultural operations 

should be uniform and consolidated into a single section applicable to all 

operations regardless of category (crops, cows, and poultry). The number of 

options a regulated entity can choose to show compliance must be increased 

significantly. Many of these practices are BACM and should no longer be 

available as options. (CVAQ)

RESPONSE: The District evaluates the effectiveness of Control Management 

Practices (CMPs) on a regular basis, as illustrated on the District’s web page 

under Requirements for Agricultural Operations. While Rule 4550 has been 

successful in reducing both PM10 and PM2.5 emissions, recent studies have 

indicated that the PM2.5 fraction of emissions makes up a small portion of the 

total particulate emissions from agricultural operations. Additionally, particulate 

emissions from agricultural operations are geologic in nature. These geologic 

particulate emissions make up a relatively small portion of the overall PM2.5 

concentrations during the winter season and have relatively low toxicity when 

compared to the organic carbon fraction of PM2.5 and to re-suspended road 

dust. Given the relatively low contribution that emissions from this category 

make to the Valley’s PM2.5 concentrations and current stringent requirements 

under Rule 4550, the District has not identified any additional rule amendment 

opportunities for further emission reductions from source categories subject to 

CMP requirements to include in this plan. As demonstrated above, Rule 4550 

currently has in place the most stringent measures feasible to implement in the 

Valley and therefore meets or exceeds both BACM and MSM requirements for 

this source category. 
San Joaquin Valley Unified Air Pollution Control District April 16, 2015 

H-10 Appendix H: Summary of Significant Comments and Responses 

2015 Plan for the 1997 PM2.5 Standard 

However, the District is leaving no stone unturned and is committing to 

reevaluate Rule 4550 for all feasible opportunities for additional emissions 

reductions, if any, in the context of the upcoming PM2.5 plans in 2016/2017. 

15. COMMENT: Emission reductions that the District intends to use from incentive 

programs under Rule 9610 are not SIP-creditable. (CVAQ)

RESPONSE: Incentive programs are an integral part of the emission reduction 

efforts of the District. These programs have invested over $1 billion in 

public/private funding towards incentive-based emission reduction projects that 

have reduced over 100,000 tons of NOx, VOC, and PM2.5 emissions since 1992. 

District incentive programs have been modeled on effective state incentive 

programs like the Carl Moyer Program. Enforceability has already been built into 

the District incentive programs through requirements that include pre and post 

project equipment inspections, monitoring, and reporting. Rule 9610 provides 

the mechanism for the District to take credit for these surplus, quantifiable, and 

enforceable emissions reductions. EPA approved Rule 9610 on February 26, 

2015, finding that incentive-based emissions reductions are fully SIP-creditable. 

 

16. COMMENT: The District should improve its public outreach process. (CVAQ)

RESPONSE: The District appreciates the recommendations for further outreach 

opportunities. The 2015 PM2.5 Plan was prepared through an involved public 

process that provided multiple opportunities for the general public and interested 

stakeholders to offer suggestions and comments for improving and strengthening 

the plan. The District has worked closely with these various stakeholders, 

including its partner agencies ARB and EPA, environmental and community 

advocacy groups, and business representatives to share information regarding 

the plan, and to receive comments and suggestions. 

Numerous opportunities were provided for public input during District Governing 

Board public hearings, Citizen’s Advisory Committee public meetings and 

Environmental Justice Advisory Group public meetings. The District also met 

with interested advocacy and industry representatives throughout the plan 

development process to address specific questions and comments, and solicit 

further suggestions for control strategies. The District held a public workshop for 

this plan on March 4, 2015 at the District’s offices in Modesto, Fresno, and 

Bakersfield and by webcast, with many participants attending and providing 

feedback. The District also posted the Proposed 2015 PM2.5 Plan on the 

District’s webpage on March 17, 2015 for a 30-day public noticing period. 

17. COMMENT: PM2.5 geologic emissions from agricultural operations are 

insignificant and attempts to control these emissions are unwarranted. There 

continues to be artificially high emissions of PM2.5 attributed to “farming 
San Joaquin Valley Unified Air Pollution Control District April 16, 2015 

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2015 Plan for the 1997 PM2.5 Standard 

operations”. There has been significant research on PM2.5 emissions from 

agricultural sources, including studies conducted in the Valley, which should be 

incorporated wherever and whenever possible. Results of the multi-year study of 

cotton gin emissions under the USDA indicate only 2.4% of total suspended 

particulate are PM2.5. Emissions from almond harvesting operations report 

PM2.5 emissions to be in a range of 1.1% to 1.6%. Additionally, ARB 

determined in 1995 that “geological material” made up less than 1% of the total 

source contributions. (APP, DC) 

RESPONSE: As described further in Appendix C of this plan, under Rule 4550 

(Conservation Management Practices), the PM2.5 fraction of emissions makes 

up a small portion of the total particulate emissions from agricultural operations. 

Additionally, particulate emissions from agricultural operations are geologic in 

nature, make up a relatively small portion of the overall PM2.5 concentrations 

during the winter season, and have relatively low toxicity relative to the organic 

carbon fraction of PM2.5 and to re-suspended road dust. 3 Accordingly, 

particulate emissions from agricultural sources do not play a significant role with 

regard to attainment of the PM2.5 standards addressed by this plan, and Rule 

4550 is primarily a PM10 reduction strategy. 

Given the relatively low contribution that emissions from this category make to 

the Valley’s PM2.5 concentrations and current stringent requirements under Rule 

4550, the District has not identified any additional rule amendment opportunities 

for further emission reductions from source categories subject to CMP 

requirements to include in this plan. It is also questionable that further 

opportunities for reducing PM2.5 emissions exist. 

However, in developing plans for the new and existing National Ambient Air 

Quality Standards, the District will leave no stone unturned to evaluate and 

identify further opportunities to advance attainment of the ever-tightening 

National Ambient Air Quality Standards. Any opportunities identified to reduce 

emissions towards meeting these tougher standards may also help expedite 

attainment with the 1997 PM2.5 standard addressed by this plan. In developing 

these plans, the District will reevaluate all of its existing regulations and will 

explore all potential measures for all source categories. As such, the District 

commits to evaluate all feasible opportunities for additional emissions reductions 

from Rule 4550, if any. 

18. COMMENT: Windblown dust is not an issue for the Valley, especially for PM2.5. 

According to USDA documents, wind erosion occurs when wind speed reaches 

13 mph, which rarely occurs in the Valley and when it does occur, it does not 

lead to exceedances of the federal standard. It has been found that only a 

fraction of suspendable particles are transportable particles and in the absence 

 

3

 Rogge, W. F., Hildemann, L. M., Mazurek, M. A., Cass, G. R. and Simoneit, B. R. T. Sources of Fine Organic 

Aerosol—3. Road Dust, Tire Debris, and Organometallic Brake Lining Dust—Roads as Sources and Sinks. 

Environmental Science & Technology 27(9), 1892-1904. 1993. 
San Joaquin Valley Unified Air Pollution Control District April 16, 2015 

H-12 Appendix H: Summary of Significant Comments and Responses 

2015 Plan for the 1997 PM2.5 Standard 

of violent winds there is little, if any, residual or continuing source of energy to 

sustain vertical motion and transport of these emissions. The District must not 

require additional control measures of agricultural sources located in rural areas. 

(APP)

RESPONSE: The Valley experiences wind-blown dust events from time to time

typically during the spring and fall seasons when weather disturbances are most 

common. These events are less likely to occur during the long stagnation 

periods of the summer and winter. When soil conditions are dry, strong wind 

events often entrain coarse particulate matter into the atmosphere, carrying the 

pollution long distances across the Valley. This phenomenon has the potential to 

create higher concentrations of PM10 in its path of impact. 

Although these events primarily cause higher PM10 concentrations, there are 

rare instances where PM2.5 concentrations become elevated. In addition to the 

rarity of elevated PM2.5 concentrations, the PM2.5 values recorded during the 

strong stagnation periods of the winter season are usually much higher than 

those recorded during wind events. Because of this, the Valley’s PM2.5 design 

values are driven primarily by high winter-time concentrations, mostly due to 

organic carbon and the secondary formation of ammonium nitrate. 

Comparatively, the geologic component of the Valley’s peak PM2.5 

concentrations is only a fraction of the mass formed through secondary 

processes and other sources. As a result, the wind events experienced in the 

Valley are not a significant contributor to the PM2.5 attainment challenges for the 

region, and placing further controls on this source would not make a substantial 

difference in the District’s PM2.5 design values. 

19. COMMENT: We appreciate the District’s inclusion of incentive programs as a 

viable emissions reduction strategy for NOx and PM2.5. We ask the District to 

include specific references to the USDA-NRCS and their California Air Quality 

EQIP Fund Pool for Particulate Matter Reduction for their incentives to reduce 

PM emissions. We support additional funding for agricultural trucks for early 

adoption and we commit to working with the District to seek out additional funds 

and help promote an incentive based program for agricultural trucks. (APP)

RESPONSE: The District appreciates the vast economic resources dedicated 

from USDA-NRCS and EQIP to incentivize zero and near-zero emitting 

technologies in the Valley. Chapter 7 (Attainment Strategy) includes a 

discussion of the collaboration between EPA, ARB, USDA-NRCS, and the 

District to adopt Rule 9610 (State Implementation Credit for Emission Reductions 

Generated Through Incentive Programs) on June 20, 2013 and effectively 

establish the administrative mechanism through which the District and ARB can 

take SIP credit for emissions reduced through these types of incentives 

previously provided by USDA-NRCS. 
San Joaquin Valley Unified Air Pollution Control District April 16, 2015 

H-13 Appendix H: Summary of Significant Comments and Responses 

2015 Plan for the 1997 PM2.5 Standard 

In addition, the District supports additional funding to help incentivize the 

replacement of agricultural trucks in the Valley. The District has included a 

commitment to fund $10 million dollars for the replacement of heavy duty trucks 

in the Valley between 2016 and 2020, and ARB has also committed to do their 

part by committing to provide additional reductions in emissions for sources 

under their control. ARB staff will propose a commitment on actions for key truck 

sectors in the Valley to better ensure benefits from the Truck and Bus regulation 

and pursue opportunities for the replacement of trucks certified to the State’s 

optional low-NOx standard. The District will continue to work closely with ARB 

on this issue. 

 
San Joaquin Valley Unified Air Pollution Control District April 16, 2015 

H-14 Appendix H: Summary of Significant Comments and Responses 

2015 Plan for the 1997 PM2.5 Standard 

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