1 Final Staff Report with Appendices 

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 SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT 

FINAL STAFF REPORT 

Revised Proposed New Rule 4566 

(Organic Material Composting Operations) 

August 18, 2011 

Prepared by: Koshoua Thao, Senior Air Quality Specialist, Rule Development 

Kai Chan, Air Quality Engineer, Permits 

Brian Clements, Senior Air Quality Engineer, Permits 

James Sweet, Senior Air Quality Specialist, Plan Development 

Sandra Lowe-Leseth, Air Quality Engineer, Permits 

George Heinen, Senior Air Quality Engineer, Permits

Reviewed by: Lori Sheridan, Air Quality Inspector, Compliance 

David Garner, Senior Air Quality Specialist, Permits 

 Mike Buss, Senior Air Quality Engineer, Permits 

 Jessica Fierro, Supervising Air Quality Specialist, Plan Development 

 Leonard Scandura, Manager, Permits 

 Scott Nester, Senior Projects Manager, Administration 

 Jim Swaney, Manager, Permits 

 Errol Villegas, Manager, Strategies and Incentives

 Samir Sheikh, Director, Strategies and Incentives 

I. SUMMARY 

Under their regulatory authority to assess the health impact of air pollutants and to 

establish air quality requirements, the California Air Resources Board (ARB) and United 

States Environmental Protection Agency (EPA) have established standards for ozone 

levels that impact public health. The San Joaquin Valley Unified Air Pollution Control 

District (District) adopted the 2007 Ozone Plan to establish the strategy for attaining the 

eight-hour ozone standards through regulatory and incentive-based measures to reduce 

emissions of nitrogen oxides (NOx) and volatile organic compounds (VOC). 

Conversion of organic material to compost (composting) emits VOC but provides 

benefits by reducing odors, eliminating pathogens, and reducing the bulk of organic 

material. In comparison to natural decay, bacterial activity in the conversion of material 

to compost provides a benefit for reduction of global warming emissions by keeping 

carbon in the bacterial cell structure thereby reducing the total amount of carbon 

escaping into the air. EPA evaluated composting and determined that the thirty year 

(life cycle analysis) retention by carbon sequestration results in reduction of global 

warming that far outweighs the other composting emissions of carbon and nitrous oxide. 

Further discussion of this topic is included in the Climate Change section of this staff 
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report. Composting converts material into a form that makes nutrients available for 

plant growth, resulting in material that is a rich soil amendment. Composting also eases 

the burden on landfills by helping cities and counties meet landfill diversion targets. 

Throughout the development of the District’s New Rule 4566 (Organic Material 

Composting Operations), which would apply to the Valley’s composting operations that 

compost and stockpile organic material, the District has sought to balance requiring 

reduction of composting VOC emissions with allowing for the continued benefits 

achieved by composting. The District’s goal in Revised Proposed New Rule 4566 is to 

reduce VOC emissions through requirements that can be feasibly implemented without 

resulting in operational expenses or finished product costs that would render 

composting operations economically inoperable. 

District efforts to develop a regulation that would reduce emissions from organic 

material composting operations began in 2007. After extensive review and 

collaboration with stakeholders, the District rescheduled the rule adoption in 2009 to 

allow for additional research and analysis. In 2009, the District collaborated with 

numerous stakeholders and agencies to direct a field study designed to measure the 

effectiveness of four candidate best management practices: finished compost cover, 

watering system, interactive management, and smaller piles. Based on the results of 

this field study, which was successfully completed in 2010, the Revised Proposed New 

Rule 4566 would focus on the finished compost cover and the watering system. The 

District has continued to work with the affected industry to address any items regarding 

control costs, technical feasibility, economic impacts, and other limitations or benefits to 

this regulatory approach. 

A. Reasons for Rule Development and Implementation

The San Joaquin Valley Air Basin (SJVAB) is nonattainment for the National Ambient 

Air Quality Standard (NAAQS) for 8-hour ozone. The Valley is also nonattainment for 

the California ozone standards. The District’s 2007 Ozone Plan included a green 

material composting control measure (S-GOV-5, Rule 4566) to reduce VOCs from this 

source category. Although VOC emissions contribute to ozone, VOC reductions are 

generally less important to the Valley’s long-term attainment goals as compared to 

reductions in NOx. However, since the District proposed to develop a rule as part of the 

2007 Ozone Plan commitment, the rule seeks to obtain as much VOC reductions as 

expeditiously practical, technologically feasible, and as economically reasonable as 

determined by the Governing Board. 

In the 2007 Ozone Plan, District staff estimated that the total VOC emissions from 

composting operations would be about 62 tons per day (tpd) in 2014, based on the best 

data available at that time. Staff noted that research was being conducted to refine the 

emission factors for this source category, since the Air Resources Board (ARB) inventories 

did not yet account for green material composting. Through collaboration with the 

composting stakeholders, current information indicates that the total VOC emission, based 
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on actual throughput levels, is about 14 tpd. The revised emission estimate is less than

previously expected, but still a significant portion of the total VOC inventory. 

Development of Revised Proposed New Rule 4566 is intended to obtain as much VOC 

emissions reduction from the source category as is technologically and economically 

feasible, as determined by the District's Governing Board. 

B. Description of the Project 

Consistent with the 2007 Ozone Plan commitments, Revised Proposed New Rule 4566 

would establish VOC limits, including operational and administrative requirements, for 

organic material composting operations. Specific composting operations that would be 

subject to the proposed rule requirements include stockpiling and composting of organic 

material. Organic material is defined in the rule as food material, green material, or a 

mixture thereof, and may include wood material and a total of less than 100 wet tons 

per year of biosolids, animal manure, or poultry litter. Composting operations with more 

than 100 wet tons of biosolids, animal manure, or poultry litter are subject to District 

Rule 4565 (Biosolids, Animal Manure, and Poultry Litter Operations) for that portion of 

the organic material. 

The District recognizes stakeholders’ efforts to comply with regulations from various 

agencies involving the disposal and recycling of organic material, particularly for 

composting. While composting of organic material is one of the desired alternative 

methods to divert reusable material from landfills, there are potential impacts to the air 

quality within the SJVAB. However, the District also recognizes that several composting 

operations are already taking measures to help reduce emissions through responsible 

composting practices. 

During composting operations, the active phase of composting is a significant part of the 

process in which the compost feedstock is rapidly decomposing. VOC emissions occur 

in the highest amounts during the active phase. Following that, the curing phase is 

characterized by lower VOC emission rates. Revised Proposed New Rule 4566 utilizes 

the significant difference in emissions between the active phase and curing phase as a 

means to focus the VOC reduction efforts to a shorter period of the compost 

development process. This focus reduces the cost of implementation of the rule while 

ensuring sufficient VOC reduction effectiveness. 

Revised Proposed New Rule 4566 would establish VOC emission reduction 

requirements on the basis of actual throughputs, rather than the maximum allowable 

capacity limits, for the composting operations, which is representative of the current 

baseline emissions for this source category. The proposed requirements are as follows: 

• Composting operations with an organic material receiving throughput of less than 

200,000 wet tons per year of organic material would be subject to the watering 
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system requirements or alternative mitigation measures that demonstrate at least 

a 19% reduction, by weight, in VOC emissions. 

• Composting operations with an organic material receiving throughput of greater 

than or equal to 200,000 tons per year and less than 750,000 tons per year 

would be subject to both the watering system and the finished compost cover 

requirements or alternative mitigation measures that demonstrate at least a 60% 

reduction, by weight, in VOC emissions. 

• Composting operations with total throughput of 750,000 tons per year or more 

would be subject to mitigation measures that demonstrate at least 80% 

reduction, by weight, in VOC emissions for organic material. 

The proposed rule further reduces VOC emissions from composting operations by 

limiting the number of days that the organic material could be stockpiled. Please refer 

to Section III (Current and Proposed Regulations) of this report for additional 

information. 

• Composting operations with less than 100,000 tons per year of organic material 

would be subject to a 10-day stockpile requirement. 

• Composting operations with 100,000 tons per year or more of the material would 

be subject to a three-day stockpile requirement. 

Table 1 shows the summary of the proposed rule requirements for composting 

operations, based on the total throughput of the composting operation. 

Table 1 – Summary of Revised Proposed New Rule 4566 Requirements 

Throughput Classification 

Proposed Requirements 

Remove or 

Cover the 

stockpile 

Composting Controls during 

Active Composting 

Throughput < 100K tpy 

Within 10 days

Watering system or an equivalent 

VOC reduction mitigation measure 

100K tpy ≤ Throughput < 200K tpy

Within 3 days 

Watering system or an equivalent 

VOC reduction mitigation measure 

200K tpy ≤ Throughput < 750K tpy Within 3 days 

Watering System and Compost 

Cover or an equivalent VOC 

reduction mitigation measure 

Throughput ≥ 750K tpy 

Within 3 days 

Mitigation measure that 

demonstrates at least 80% 

reduction, by weight, in VOC 

emissions 
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C. Rule Development Process 

District staff began the rule development process with extensive research in 2007, 

which was followed by a public scoping meeting on January 10, 2008. Based on the

research conducted and information obtained with the best available data, the District 

created a draft version of Rule 4566 that proposed to adopt a menu based approach 

and require the implementation of various management practices (such as monitoring 

carbon to nitrogen ratios, moisture content measurements, oxygen concentration, etc.), 

including installation of engineered control systems. To obtain comments on the draft 

rule, the District held a public workshop in April 2008 and convened several site visits 

and technical workgroup meetings during 2008 and 2009 to work with various 

stakeholders to address costs, technical feasibility, economic impacts, and other 

limitations or benefits to this regulatory approach. 

Although the meetings and visits in 2008 were intended to culminate in the Governing 

Board adoption of Rule 4566 in the first quarter of 2009, information that came to light 

during those meetings showed that more time would be needed to increase the 

scientific justification behind proposed rule requirements which would allow the District 

to develop an effective composting rule. District staff had determined that emissions 

from this source category were much lower than previously estimated in the 2007 

Ozone Plan. There was also insufficient information available, at that time, on the 

effectiveness of reducing VOCs from potential mitigation measures. For these reasons, 

District staff determined that additional time was needed to study the effectiveness of 

various control methods. District staff therefore requested an extension to the rule 

development schedule, and the District Governing Board amended the 2007 Ozone 

Plan on December 18, 2008 to extend the Rule 4566 adoption schedule from the first 

quarter of 2009 to the fourth quarter of 2010. 

In 2009, multiple agencies contributed $200,000 for the composting field study, which 

was conducted at Tulare County Composting by the San Diego State University 

Research Foundation. The District engaged in extensive stakeholder involvement and 

numerous technical workgroup meetings to help define the parameters of the field 

study. Participants of these meetings included composting operators, ARB, California 

Department of Resources Recycling and Recovery (CalRecycle), agricultural groups, 

environmental advocates, other air districts, and city and county agencies. The results 

of this study were successfully completed in 2010 and formed the basis for the Revised 

Proposed New Rule 4566. The compost study identified two promising mitigation 

measures, watering system and finished compost covers. 

In September 2010, the District held a workshop to present and discuss the proposed 

rule concepts. Based on the results of the study, the District drafted rule requirements 

that would require facilities with annual throughputs of more than 10,000 tons year and 

less than 25,000 tons per year to implement the watering system requirements, 

whereas, composting facilities with throughputs greater than 25,000 tons per year would 

have been required to implement the finished compost cover. Based on the industry 
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reaction to the proposed rule requirements, District staff worked closely with the 

affected stakeholders to refine the rule requirements, as well as address the cost 

impacts to affected facilities and feasibility concerns for the watering system and 

finished compost cover requirements. The District convened additional technical 

working group meetings to discuss potential applicability thresholds greater than the 

10,000 ton per year limit and refine other proposed rule requirements. 

Approaching the extension deadline with a number of questions still remaining 

regarding the feasibility and cost of actually implementing these various potential 

emission reduction strategies; in December 2010, District staff provided an update to 

the District’s Governing Board on the status of this project with plans to bring forth a 

proposed rule for Governing Board consideration in 2011. 

Following the December 2010 Governing Board update, District staff continued to work 

closely with stakeholders to address these remaining issues. District staff conducted 

weekly discussions with affected operators and composting representatives to obtain 

cost estimates and devise solutions to overcome feasibility questions. Staff and 

management have conducted additional site visits throughout the Valley to discuss 

stakeholder concerns in person and in order to better understand the implications of 

proposed rule requirements to the operations. Based on the collaboration with the 

interested stakeholders, the District was able to refine the rule requirements and 

minimize the overall impacts associated with the proposed rule. 

During this time period, District staff also collaborated with South Coast Air Quality 

Management District (SCAQMD) staff to share information as they concurrently work to 

develop a rule impacting similar sources in their region. Outreach efforts have also led 

to discussions with CalRecycle and Local Enforcement Agency (LEA) staff to discuss 

chipping and grinding regulations and the state’s Title 14 requirements. 

Based on several discussions and additional information from stakeholders, District staff 

was able to refine the draft rule concepts to include detailed information on the watering 

system requirements for composting operations with less than 200,000 tons per year of 

organic material and finished compost cover requirements for composting operations 

with 200,000 tons per year or more of organic material. To further solicit input from 

affected stakeholders, the District held a technical working group meeting in March 

2010 and presented the revised rule concepts to the workgroup. The rule concepts 

would allow operators the ability to comply with the requirements with minimal impact to 

the composting operations. District staff also addressed operators concerns with rain 

events and water run off issues with implementing the watering system. After the 

meeting, District staff continued to work with the operators to address the costs of 

implementing the mitigation measures, update the facility throughput information, and 

gather information on the feasibility of implementing the finished compost cover. 
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While feasibility concerns were no longer a primary concern, costs of implementing the 

proposed rule requirements was still a concern for one operator. Staff has worked 

closely with this operator to understand and refine their cost estimates to develop the 

best information possible for evaluation of potential rule requirements. 

District staff conducted a public workshop on June 23, 2011 to present, discuss and 

receive comments on the draft rule, staff report, and a socioeconomic analysis report. 

As with previous workshops, the District provided a two week commenting period after 

the workshop for any additional public comments. During the commenting period, 

District staff continued to work with the affected stakeholders to resolve any remaining 

concerns, specifically on industry’s costs of implementing the watering system and the 

feasibility of implementing the finished compost cover for one facility. District staff has 

incorporated the additional information received from stakeholders into the staff report 

and proposed rule, as appropriate. To address the remaining operator’s concern with 

implementing the finished compost cover requirements, the proposed rule would extend 

the schedule for the finished compost cover to five years. District staff recognizes the 

potential implications that the proposed requirements may have on the remaining 

operator’s facility and will continue to work with the operator to evaluate ways to comply 

with the rule. The schedule would allow the operator to determine and develop effective 

control strategies specific to the facility’s operation. The additional time would also 

allow for any incremental absorption of costs or increase in tipping fees/sales. 

 

The proposed rule, staff report with appendices, and final draft socioeconomic analysis 

report were published on July 19, 2011. The publication provided affected sources and 

interested parties additional opportunities to review and comment on the proposal prior 

to the public hearing before the District Governing Board. On August 18, 2011, the 

District Governing Board unanimously approved the adoption of the Revised Proposed 

New Rule 4566. 

To gain first-hand knowledge of these operations, District staff conducted several visits 

to the following composting facilities since 2008: 

• City of Modesto 

• Community Recycling Lamont Composting Facility 

• Highway 59 Compost Facility 

• Mariposa County Solid Waste Composting Facility 

• South Kern Compost Manufacturing Facility 

• Tulare County Composting & Biomass, Inc. 

• Recology Grover Environmental Products (Vernalis) 

II. BACKGROUND 

Composting material can enrich the soil, replace fertilizer, divert waste from landfills, 

and serve other purposes. Composting is often advantageous for bulk reduction, 
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pathogen reduction, and odor reduction. It also produces a material with various 

beneficial uses, such as landscape, soil amendment, road use, and alternative daily 

covers (ADC) at landfills. Composting also helps local government agencies meet state 

solid waste diversion goals to preserve landfill capacity by reducing the amount of 

organic waste sent to landfills for disposal. 

The composting industry has been expanding and will continue to expand. 

CalRecycle’s Strategic Directive 6.1 aims to reduce the amount of organics in the waste 

stream by 50% by 2020. Diversion of half of CalRecycle’s 2006 baseline of 29.7 million 

tons would require the development of 50 to 100 new composting operations in 

California. While diversion of materials from landfill disposal to composting will help 

ease the burden on landfills and achieve associated environmental benefits, the 

increase in composting will also increase VOC emissions associated with the operations 

and possibly NOx emissions from increased trucking of organic materials from outside 

of the SJVAB. Implementation of the proposed mitigation measures can help minimize 

impacts in the Valley. Air quality goals must be balanced with diversion goals. The 

primary objective of Revised Proposed New Rule 4566 will be to reduce VOC emissions 

from organic material composting operations, including stockpiling at composting 

operations, as required in the 2007 Ozone Plan, without making composting cost 

prohibitive. 

A. The Composting Process 

Organic material naturally decomposes by both bacterial (biotic) and nonbacterial 

(abiotic) natural processes. Organic waste decomposes naturally in the presence of 

water, warmth, and oxygen. Composting accelerates the process of decomposition by 

adding moisture and creating a physical arrangement (such as windrows) that maintain 

an elevated temperature and provide an ideal environment to facilitate biotic 

decomposition to transform the stock material into nutrient-rich humus like material 

commonly referred to as compost. The composition and density of stock material affect 

the rate of decomposition. 

The composting process typically involves six major steps: 

1. Recovery and Preparation. Operators receive the organic material from either 

private or public industries and may screen the material for physical 

contaminants, pursuant to Title 14, Div. 7, Chapter 3.1, Article 7, Section 

17868.5. The feedstock may also need to undergo chipping or shredding to 

obtain the appropriate size material for the composting process. 

2. Mixing. Feedstock may be mixed with additives or amendments to adjust the 

bulk weight, carbon to nitrogen ratio, moisture content, and porosity of the 

material. The mix enhances the composting process, provides structural support 

for the compost piles, or produces compost with specific characteristics. 

Operators often select additives and amendments based on availability, cost, and 
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degradable content. Some additives and amendments include overs, peanut 

hulls, rice hulls, sawdust, straw, shredded tires, and wood chips. However, 

shredded tires and wood chips do not readily compost and may be recycled 

through multiple composting cycles. 

3. Piling. The compost material is typically placed into piles on open fields or 

enclosed in an in-vessel system. The piles can stretch up to a few hundred 

yards in length. 

4. Active Composting. Microorganisms break down the material and consume the 

most easily degradable organic matter. These microorganisms give off 

significant heat, raising the temperature of the compost and destroying 

pathogens. The material is aerated by turning or by forcing air through the piles 

to provide oxygen for the microorganisms. Most of the VOC emissions 

generated by composting are expected to occur during the active stage. 

5. Curing Composting. The microbial populations shift to bacteria and fungi, 

which break down the less degradable organic matter like chitin, cellulose, and 

lignin. The curing process stabilizes the compost by transforming it to a material 

that cannot be further easily decomposed. Heat and VOC emissions are more 

stable during the curing phase, as compared to the active compost phase. 

6. Finished Composting. During the final stage, compost may be stored to 

complete the maturing process and to ensure that the compost material is 

resistant to further microbial breakdown, which could potentially harm living 

plants. Once the maturing process is complete, the finished compost undergoes 

screening for sale or use. 

B. Composting Parameters for Windrow Composting 

Operators maintain their windrows within specific parameter ranges to efficiently convert 

the incoming materials to finished compost. The parameters discussed in this section 

are oxygen, temperature, moisture, pH, and carbon-to-nitrogen ratio. The parameters 

affect the immediate environment and interact with each other. As an example, readilyavailable carbon can increase the microbial activity which increases the temperature of 

the windrow. The increased activity decreases the oxygen level within the pore space 

because the microbes utilize the oxygen as part of the degradation process. The 

increased temperature may cause the water to evaporate faster, reducing the moisture 

in the vicinity of the increased microbial activity. Decreased moisture can mean that the 

temperature increases even more because there is less water to absorb the heat 

generated by the composting reactions. Or, if too dry, the microbes can go dormant or 

die from lack of water. 

Although the parameters described below are measurable characteristics of effective 

composting operations, District staff is not considering a prescribed range of values for 
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the parameters as part of the proposed rule requirements for organic material. Based on 

discussions with the composting operators, many of the parameters below are already 

being monitored as part of the composting operation to promote best practices and to 

produce quality products. Since the composting process is unique to each facility, there 

are several methods that operators use to define these parameters. To require specific 

test methods for these facilities would potentially result in significant costs and change 

in operation to the affected operators. For this reason, the provisions of Rule 4566 will 

focus on other compost emission control strategies. 

Oxygen 

Aerobic processes utilize oxygen acquired from the environment, namely through the 

diffusion of oxygen from air into the water film where the aerobes (microorganisms that 

utilize oxygen in their life processes) reside. Maintaining a healthy oxygen level within 

the pore space promotes aerobic respiration—which in turn, increases biological 

breakdown of the composting materials and reduces odors As the oxygen level in the 

area decreases, anaerobic microorganisms increase at the expense of the aerobes 

because the aerobes have less oxygen available for their life processes. 

In order to reduce the amount of anaerobic degradation, the pore-space’s air needs to 

be “refreshed” from time to time as the aerobes use up the available oxygen in the 

enclosed space. The simplest way to get more oxygen to the aerobes is to break up the 

windrow and re-mix the partially-composted material. The pore-space is broken up and 

exposed to fresh air and re-formed into a windrow in a “turning event.” In an ideal 

turning event, the windrow material is completely rearranged where all of the porespaces are broken open, exposed to fresh air, and then reformed into new pore spaces. 

Moisture 

Water plays an essential role in composting. It serves as the medium for the 

microorganisms that perform the decomposition. Water is also an extraction solvent to 

remove organic molecules from the substrate and from the air. Because of its fluidity, 

water serves to circulate oxygen and extracted compounds to the aerobes as well as 

circulating expelled compounds to other microorganisms in the water film. Water also 

absorbs heat from the chemical breakdown of the organic molecules. 

In composting, there must be enough water to perform all the necessary functions, but 

not so much water that the aerobes drown, meaning that there is not enough oxygen 

diffusing into the water film where the biological activity is taking place to allow aerobic 

decomposition. On the other extreme, there should not be so much air passing through 

that the water film evaporates. As a rule of thumb, windrow moisture content between 

40% and 70% is ideal for composting. Below 40%, microbial activity becomes very 

limited. Above 70% moisture content, the pore is so filled with water that there is little 

air in the pore space, and therefore, the aerobes use up the available oxygen in a short 

time. A windrow’s overall moisture content can be maintained by turning the windrow to 

break up pockets of too wet or too dry material and more evenly distribute the moisture 

within the windrow. 
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Temperature 

Temperature can be an indication of biological activity for composting operations and is 

fairly easy to measure. However, the temperature does not necessarily indicate that 

there is biological activity in the windrow, especially on certain summer days, between 

high air temperature and a sunny location. 

Assuming that there are other indications of microbial activity, the temperature increase 

in a composting windrow is due to the chemical reactions performed by the microbes, 

which liberate heat as a by-product of the reaction. In general, windrow temperatures 

between 20°C and 60°C (72°F and 140°F) are ideal since it is indication of desirable ongoing biological processes. Above about 65°C (150°F), microbial activity is hindered. 

Additionally, piles may burn at high temperatures; so many operators have a maximum 

temperature that they use to trigger a turning event. 

The temperature in an active windrow can affect compost operations in variety of ways. 

Since higher temperatures indicate high microbial activity; the oxygen level in the pore 

space would be depleted quickly causing anaerobic conditions discussed above. For 

this reason, some operators turn composting windrows more frequently during the early 

stage of composting to dissipate heat generated by intense microbial activity. 

pH 

In any biological process, pH is an important factor since it affects the microbial activity. 

Most organisms require a growth media with a near-neutral pH, meaning pH in the 

vicinity of 7.0. 

Carbon to Nitrogen (C:N) Ratio 

All organic matter is made up of substantial amounts of carbon (C) combined with lesser 

amounts of nitrogen (N). The balance of these two elements in an organism is called 

the carbon-to-nitrogen ratio (C:N ratio). For best performance, the compost 

microorganisms require the correct proportion of carbon for energy and nitrogen for 

protein production. Composting organisms use about 30 times more C than N. 

However, the carbon and nitrogen must be in a form that the microorganisms can 

process. Woody materials, for example, have carbon that is difficult for the composting 

microorganisms to extract, so even though there is high amounts of carbon in woody 

material, it cannot be used directly by most microbes. In a compost windrow with a 30:1 

carbon-to-nitrogen ratio that utilized only wood chips as the carbon source, composting 

may not actually occur because the carbon in wood chips is not readily available to the 

microorganisms and the organisms might starve for lack of an energy source. 

In addition, operators may not be able to choose the composition of their feed stock. 

Municipalities with curbside recycling, for example, must accept and process the 

material brought to the composting operation through the curbside program, regardless 

of the gathered materials’ makeup. The type of organic material accepted at the 

compost operations could also vary from season to season. 
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C. Locally Studied VOC Emission Control Technologies for Composting 

District staff obtained an understanding of composting factors through discussions with 

stakeholders and scientists who have researched compost emissions. Some factors 

that affect the process of composting require professional judgment by the operator 

during the composting process, while other factors provide a more routine and 

quantifiable response that was determined to be more suitable for research on possible 

mitigation approaches. District staff, in discussion with stakeholders, set up a research 

evaluation of composting in 2009, designating one windrow as a scientific “control” with 

standard procedures to compare to other windrows with application of water prior to 

turning; application of finished compost cover to act as a passive biofilter; alternative 

interactive management; and a small windrow reducing the height and volume 

compared to the control. During the composting process, the compost pile is turned 

every few days to prevent compaction and maintain air space within the pile material. 

The finished compost cover was reapplied after each turn during the composting 

process for one windrow. 

Based on the study results (SJVAPSA, 2011), both the practices of applying water 

before turning and of applying a finished compost cover after turning were found to 

reduce VOC emission. The following figure provides a comparison of the control 

windrow to the windrow with application of finished compost applied as a cover. Figure 

1 show that most of the VOC reduction is accomplished in the first 22 days which was 

the time period of the active phase of composting for the control windrow. 

Figure 1 - Compost Emission Comparison

0

50

100

150

200

250

300

350

400

2 3 5 7 10 15 22 29 36 41 50 64 78 99

Day of Composting Process

VOC Emissions *

Typical Compost Windrow

Application of Finished Compost Cover

* VOC measurements are comparison values, not converted to per compost ton or per windrow units

Source: Appendix I to study results report (SJVAPSA, 2011) 
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Reducing volume of the windrow was found to actually increase VOC emissions. 

Interactive management was determined to be a difficult process to quantify. In addition 

to the research results, staff learned from stakeholder and researcher communications 

about other factors that have been found to negatively impact the composting process. 

For example, stacking materials too high or compacting materials too tightly causes 

areas of the pile to have low oxygen levels, resulting in anaerobic decomposition, which 

increases odor emissions. Odor emissions include some VOC compounds, therefore, 

proper management to control odor may also reduce VOC emissions. 

D. Potential VOC Emission Control Measures for Composting 

In addition to the methods examined in the District’s composting study, available 

technologies for collecting and controlling VOC emissions are described below. Several 

of these control technologies are currently operated by a few co-composting operations, 

which handle primarily biosolids, animal manure, and poultry litter. These facilities are 

relatively new and designed their facilities to include these controls to satisfy Best 

Available Control Technologies (BACT) and other permitting requirements. At this time, 

District staff is not aware of any composting operations in the SJVAB that operate these 

controls for organic material. 

Aerated Static Pile (ASP) system 

For the ASP method, operators pile the feedstock over a base of porous materials. 

Perforated pipes or plates are connected to a blower that either pulls (negative 

pressure) or pushes (positive pressure) air through the pile. Several operations in 

California and other parts of the country use ASP vented to controls, such a biofilter, 

with control efficiencies of at least 80%. Additional information on these controls can be 

found on the following page. 

There are two forms of ASP systems. The first form generally uses long triangular piles 

with a base width that is two times as long as the height. Aeration pipes run lengthwise 

beneath the ridge of each pile and serve the entire pile. Each pile contains feedstock of 

roughly the same mixture and age. 

The second form uses extended piles consisting of individual cells that are stacked 

against each other. Cells of new feedstock are constructed in one pile, and cells of 

nearly mature compost are placed in another pile. The space between the piles allows 

for the removal of old cells from one pile and the addition of new cells to another pile. 

Generally, there is also an individual blower and timer during the aeration process of 

each cell. The captured VOC emissions from the ASP system may be transferred to a 

control, such as a biofilter, for VOC reductions. 

Enclosed Aerated Systems 

In enclosed aerated systems, the material is placed in a bag, container, or other 

enclosure, and then the material is aerated. The aeration method controls moisture, 

temperature, and airflow; however, it does not vent the air in the enclosure to a control 
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device. The system achieves VOC emission reductions by increasing the percent of 

aerobic composting and decreasing the percent of anaerobic composting by providing 

oxygen to promote aerobic activities. 

Within-Vessel and In-Vessel Composting

The within-vessel and in-vessel composting methods allow the operator to control the 

moisture, temperature, and airflow to a more exact science and to capture most of the 

emissions. The VOC capture efficiency for in-vessel systems ranges from 90% to 99%, 

while the VOC capture efficiency for within-vessel systems ranges from 70% to 90%. 

Within-vessel composting operations are performed by processing the feedstock 

material and loading it into bags or containers. In-vessel composting operations occur 

in a permanent enclosure under negative pressure. An electric blower system controls 

airflow and temperature for both systems. A secondary control receives and further 

reduces the captured VOC emissions. The secondary control includes, but is not 

limited to, a biofilter or a liquid capture and control system. 

VOC Controls, including biofilters 

VOC controls can reduce VOC emissions captured from collection systems, such as 

ASPs. Typical VOC controls include biofilters, carbon adsorption systems, and packed 

tower scrubbers. Biofiliters are the most commonly-used controls at composting 

operations. Currently, biofilters are used at over 200 composting operations in Europe, 

over twenty composting operations in the U.S., and at least five composting operations 

in California. 

The typical biofilter design consists of fans, ducts, media support (a bed liner), an air 

plenum, and the media (often a blend of finished compost or soil, and wood chips). 

Wall ventilation and pit fans blow air from the building and pit through ducts, then into an 

air plenum below the biofilter media. The air passes through the media, where 

microorganisms treat the air before it escapes to the atmosphere. Figure 2 shows a 

schematic of an enclosed biofilter system. Recent District BACT determinations 

indicate that biolfilters have a VOC destruction efficiency of at least 80%. 

Figure 2 - Sample Biofilter Design 

Scrubbed 

Exhaust Air

Enclosure 

with Compost 

Pit 

Air Duct 

Air Plenum 

Media Vent 

Fan 

Biofilter Set-Up 
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Aside from biofilters, stakeholders have also indicated the possibility of applying 

pseudobiofilters (or finished compost covers) on top of static piles or aerated static piles 

as a viable emission reductions technology. The application has been used in many 

situations to reduce odors from composting facilities. District staff is currently not aware 

of studies that show actual reduction in VOC when applying the finished compost cover 

on top of static piles or aerated static piles. However, based on recent field studies, the 

use of finished compost cover on top of windrows has shown to be an effective 

mitigation measure in reducing VOC. The actual VOC reduction from the finished 

compost cover application could vary between windrow composting and static piles or 

aerated static piles, which operate differently. The District will consider any future 

studies and information on the effectiveness of using finished compost on top of static 

piles and aerated static piles for organic materials. 

III. CURRENT AND PROPOSED REGULATIONS 

A. Current Regulations 

District staff has reviewed applicable regulations from the District, other air districts, and 

other agencies to assist in the development of Revised Proposed New Rule 4566. 

District Rule 4565 (Biosolids, Animal Manure, and Poultry Litter Operations), which was 

adopted in March of 2007, regulates the composting and co-composting of biosolids, 

animal manure, and poultry litter. Currently, the District does not have any prohibitory 

rules that specifically regulate VOC emissions from composting and stockpiling of 

organic material. 

The development of Revised Proposed New Rule 4566 is not intended to replace any 

more stringent local, state, federal, or other governmental agency requirements. Where 

multiple rules apply to a facility, the operator must comply with all applicable rules. 

Composting operations in the Valley may also be subject to regulations from other 

agencies: 

• Title 14, Div. 7, Chapter 3.1 Article 6, Section 17867, along with other California 

Code of Regulations; 

• Waste discharge requirements of the Porter-Cologne Water Quality Act 

(California Code of Regulations Section 13020), as administered by the Regional 

Water Quality Control Board (RWQCB). Based on discussion with RWQCB, 

composting of organic material, specifically green material, is not currently 

regulated by the agency. 

B. Review of Other Air District Related Regulations

The South Coast Air Quality Management District (SCAQMD) and Antelope Valley 

AQMD have adopted regulations for co-composting (composting that involves animal 
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manure or poultry litter). Green material composting operations is not currently 

regulated by Antelope Valley AQMD. SCAQMD recently adopted Rule 1133.3 

(Emission Reductions from Greenwaste Composting Operations) for composting of 

green material and food material. As previously mentioned, District staff collaborated 

with SCAQMD staff to share information as they concurrently work to develop a rule 

impacting similar sources in their region. Please refer to the Reasonable Available 

Control Technology section for further discussion on SCAQMD’s Rule 1133.3. 

C. Proposed Regulation 

1. Section 1.0 Purpose / Section 2.0 Applicability 

Revised Proposed New Rule 4566 would limit VOC emissions from composting 

operations, which include composting and stockpiling of organic material at composting 

operations. Revised Proposed New Rule 4566 would regulate organic material, which 

is defined as food material, green material, or a mixture thereof, and may include wood 

material and a total of less than 100 wet tons per year of biosolids, animal manure, or 

poultry litter. Other than recordkeeping, wood material that is source separated and is 

not mixed with other organic material is exempt from the proposed rule requirements. 

Revised Proposed New Rule 4566 would allow operators to compost a total of less than 

100 wet tons per year of biosolids, animal manure, or poultry litter to address materials 

that operators may inadvertently receive at the facility for composting. 

2. Section 3.0 Definitions

Several definitions presented in this rule are from existing regulations from the District, 

other air districts, and state and local agencies. District staff also included additional 

definitions to further clarify the intent of the proposed rule requirements. 

The definitions for the active phase and curing phase are intended to provide operators 

the flexibility to choose from several methods to comply with the rule requirements. As 

explained in Section II.C., Figure 1, most of the VOC emissions occur in the first 22 

days for a typical windrow, which is the time period of the active phase. The curing 

phase begins immediately after the active phase and typically last for a period of 40 

days. The number of consecutive days for both active phase and curing phase would 

be considered the lower time limit, unless operators determine a shorter time limit 

through other test methods. The test methods in the proposed rule include: Specific 

Oxygen Uptake Rate, Carbon Dioxide Evolution Rate, and the Solvita® Maturity Index. 

However, operators may use an alternative test method to satisfy the rule requirements 

for which a written approval from the APCO has been obtained. The test methods 

would typically be used in cases where operators implement other alternative mitigation 

measures that result in shorter time periods. The number of days and various test 

methods for the active phase and curing phase are currently used in practice and are 

similar to the definitions from the following air districts’ rules: 
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• San Joaquin Valley Unified APCD - Rule 4565 (Biosolids, Animal Manure, and 

Poultry Litter) 

• South Coast AQMD - Rule 1133.2 (Emission Reductions from Co-composting 

Operations) 

• Antelope Valley AQMD - Rule 1133 (Composting and Related Operations) 

The limits for the test methods above are from the Compost Stability Index (Table 

05.08-1), which can be found in the Test Methods for the Examination of Composting 

and Compost (TMECC) manual by the US Composting Council Research and 

Educational Foundation. 

3. Section 4.0 Exemptions

Stockpile and composting operations that are subject to Rule 4565 (Biosolids, Animal 

Manure, and Poultry Litter Operations) would be exempted from Revised Proposed New 

Rule 4566. However, a facility could have two operations on site where both Rule 4565 

and Revised Proposed New Rule 4566 would apply. Composting operations claiming 

exemption under Rule 4565 must handle biosolids, animal manure, or poultry litter as 

part of the operation but would only be exempted for the materials that are cocomposted. If the operator also had a composting operation that did not include cocomposted material, then that part of the facility would fall under Rule 4566. 

Other Stockpile Operations 

Operations that stockpile organic material and are not required to obtain a composting 

permit from the District or a Compostable Materials Handling Facility Permit in 

accordance with Title 14 would be exempt from Revised Proposed New Rule 4566 

requirements. An example of when a facility would have one permit and not the other is 

a facility that does not compost organic material but has a Compostable Materials 

Handling Facility Permit. Title 14 has more stringent stockpile requirements for chipping 

and grinding operations; however, there are currently no stockpile requirements for a 

site that is regulated as a compostable material handling operation or facility. 

There are several small-scale operations that typically generate and process the 

organic material on site, where immediate access to daily covers or other resources are 

not available. Other examples include small community-operated 

residential/neighborhood organic material drop-off sites where small residential 

communities do not have access to truck collections and have a designated location to 

drop off organic materials, such as yard clippings. These sites typically have roll-off 

containers for the incoming organic materials. Small community drop off sites, that use 

containers and manage the site, encourage trip reduction and is an economically viable 

option for many small residential communities. The operations above do not compost 

and do not have a Compostable Materials Handling Facility Permit. 

Revised Proposed New Rule 4566 would exempt stockpiling of wood material, finished 

compost, overs, and organic material that is used specifically for animal feed or 
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nutritional products, provided that the material is not mixed with other organic material 

and the operator maintains records. Wood material is typically a dry material, which has 

a low moisture level and is slow to compost. Wood material that is separated from 

green material prior to complying with the stockpile requirements would also be exempt 

from the proposed rule. For finished compost, the material has already gone through 

the composting process and has minimal emissions. Overs have also gone through the 

composting process and primarily consist of woody material; therefore, overs would be 

treated the same as wood material and finished compost. As explained in Section II.B., 

the low level of moisture content or lack of nitrogen in these materials would limit their 

biological breakdown. 

In addition to recordkeeping and not mixing the organic material that is stored for animal 

feed or nutritional products with other materials at a composting facility, the proposed 

rule would not allow operators to conduct pathogen reduction on the organic material. 

Organic material that is used for animal feed or nutritional products would not be subject 

to the stockpile requirements for composting operations as the organic materials are 

treated differently from typical composting operations. 

Other Composting Operations 

The proposed rule would exempt small-scale composting and composting of organic 

material that is generated and used onsite. Specific composting operations that would 

be exempt from the proposed rule includes agricultural composting, community 

composting, household composting, nursery composting and recreational facilities 

composting. 

Other Operations 

Also exempt are facilities and operations that handle organic material as part of their 

operations and are already subject to similar requirements from other District rules. 

Facilities and operations that would be exempt under Section 4.0 include the following: 

• Facilities subject to Rule 4204 (Cotton Gins) and cotton ginning facilities that are 

specifically exempt from Rule 4204. 

• Agricultural operations subject to Rule 4550 (Conservation Management 

Practices) and agricultural operations that are specifically exempt from Rule 

4550. 

• Facilities subject to Rule 4570 (Confined Animal Facilities) and facilities that are 

specifically exempt from Rule 4570. 

4. Section 5.0 Requirements 

Section 5.0 addresses requirements for stockpiling and composting operations. 

Stockpile Requirements 

The proposed rule would reduce VOC emissions from composting facilities that 

stockpile organic material. Organic material that would be exempt under Section 4.0 
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would not be subject to the requirements under this section. For operations that do not 

compost but stockpile the organic material on site and have a compostable materials 

handling facility permit in accordance with Title 14, operators would be required to 

comply with all applicable stockpile requirements. As previously mentioned in the 

Exemptions section, Title 14 does not have stockpile provisions for a site that is 

regulated as a compostable material handling operation or facility. 

Operators that receive organic material at a composting facility typically stockpile the 

material until there is enough material onsite to chip or grind and put into windrows. 

The organic material may be stockpiled up to several days, depending on the amount of 

materials that a facility receives. For example, a facility that receives fewer amounts of 

materials on a daily basis may require more days to generate enough materials to form 

a windrow for composting. To reduce emissions from stockpiles, operators of 

composting operations, with throughputs less than 100,000 wet tons of organic material 

per year, would be required to remove the materials from the facility or compost the 

material within ten days of receipt. Composting operations with throughputs of 100,000 

wet tons of organic materials or more per year would be required to remove the 

materials within three days of receipt. 

According to information received from composting operators that handle less than 

100,000 wet tons of organic material per year, the number of days that the materials are 

stockpiled onsite can vary up to 21 days, depending on the facility. Day one of the 

stockpile begins on the first day that organic material is received and placed into a 

newly formed pile. The day the same stockpile is removed or covered, regardless of 

whether new organic material is added to the stockpile, is the end date. 

Based on information received from the operators, District staff has determined that 10 

days is reasonable for operators that have less than 100,000 wet tons per year of 

organic materials to remove the stockpile. The 10 day limit was determined as follows: 

• Up to 3 business days to receive enough organic material for a windrow 

• Up to 2 business days to chip and grind organic material 

• Up to 2 business days to move the chipped or ground material for composting 

• Up to 3 non-working days to compensate for weekends and holidays 

The breakdown of the days above is based on discussion with operators. However, the 

chipping and grinding process could occur at anytime within the 10-day limit. District 

staff does not expect the chipping and grinding process to have a significant impact on 

the stockpile holding times because the stockpile emission factor takes into account 

emissions from stockpiles that have been chipped and ground and stockpiles that have 

not been chipped or ground. Composting operators subject to this requirement have 

indicated that they either already satisfy or would be able to satisfy the requirements. 

For composting operations with throughput of 100,000 tons per year or more, operators 

would have up to three days (of receipt) to remove or cover the organic material. Based 
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on information received from composting operators that process 100,000 tons per year 

or more of organic materials, the operations already satisfy the requirements. 

While many operators already satisfy the stockpile holding times above, establishing the 

requirements not only help capture emissions from some operations that currently 

stockpile the materials longer, but would help minimize stagnant piles. 

The District will not address operations from land application, land incorporation, and 

other operations that stockpile organic material as part of the proposed rule since there 

is not enough information at this time to obtain additional VOC reductions from these 

operations. Additional information includes the number of operations in the SJVAB, the 

number of stockpiling days, and the actual throughput. Land application and land 

incorporation are generally excluded under Title 14 regulations. While District staff 

intends to obtain as much reductions as possible from this source category, additional 

reductions from other operations would be difficult to achieve without sufficient data. In 

addition, the control measure for Revised Proposed New Rule 4566 was intended for 

composting operations that process green materials and therefore, District staff will 

address those operations at this time. District staff will address any additional 

reductions from other source categories as part of future projects. 

 

Table 2 – Summary of Stockpile Requirements 

Operations

Subject to 

Control

Proposed Rule Requirements Minimum Number 

of Stockpile Days 

Throughput < 

100,000 tpy 

• Remove organic material from the facility, or 

• Start the active phase of composting, or 

• Cover the material, or 

• Implement an alternative 

10 days of Receipt

Throughput ≥

100,000 tpy 

• Remove organic material from the facility, or 

• Start the active phase of composting, or 

• Cover the material, or 

• Implement an alternative 

3 days of Receipt 

*tpy: tons per year 

Composting Requirements 

Data from the San Joaquin Valley Air Pollution Study Agency’s (Study Agency) field 

study showed that the watering system would provide a 19% reduction in VOC 

emissions during the active phase. In addition, application of finished compost as a 

cover (acting as a passive biofilter) during the active phase can achieve a 56% 

reduction in VOC in comparison to standard operations of windrow composting without 

the finished compost cover. The field study demonstrated that these methods are 

effective in reducing VOC emission from composting of organic material and are 

feasible to implement. District staff has also considered combining both the watering 

system and finished compost cover requirements, since both mitigation measures have 

been achieved in practice at one composting facility in the Valley. By requiring both the 

watering system and finished compost cover application, operators would be able to 
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achieve 60% reduction in VOC. Please refer to Appendix B for further discussion on the 

reduction limit. 

Composting procedures, equipment, and resources typically vary among the 

composting operations in the SJVAB. The rule concepts for the selected mitigation 

measures below takes into account the processes conducted as part of the field study 

and the processes that would be feasible for operators to implement. Operators would 

have the flexibility to implement the control options using equipment and resources that 

are available and appropriate for the facility’s composting operation. The mitigation 

measures described below are for the active phase of composting only. For windrow 

composting, the proposed rule would require a minimum of three turns during the first 

22 consecutive days, for both mitigation measures. Based on discussion with the 

operators, District staff has found that three turns is the minimum number that could be 

achieved as part of a facility’s typical composting operation during the active phase. 

The throughput threshold for the composting operations was determined based on the 

District’s feasibility and economic analyses, which are further explained in Appendix C 

of this staff report. 

Table 3 – Summary of Composting Requirements during Active Composting 

Operations Subject to 

Control Proposed Rule Requirements 

Minimum % Reduction, 

by Weight, in VOC 

Emissions 

Throughput < 200K tpy • Implement a watering system2

, or 

• Implement an alternative At least 19% 

200K tpy ≤ Throughput 

< 750K tpy 

• Implement a watering system2

and finished compost cover3, or 

• Implement and alternative 

At least 60% 

Throughput ≥ 750K tpy 

• Implement an engineered control 

system, or 

• Implement an alternative 

At least 80% 

1. tpy: tons per year 

2. Watering system requires a minimum of three turns during active composting and would be 

implemented after one year of rule adoption. 

3. Finished compost cover requires a minimum of four covers for initial windrow formation and three turns 

and would be implemented after five years of rule adoption. 

Composting Operations with Total Throughput less than 200,000 TPY 

Revised Proposed New Rule 4566 would require operators of composting operations 

with total throughput less than 200,000 tons per year of organic material to implement 

the watering system requirements during the active phase. Operators would use a 

watering system to apply water to the windrow before turning, or use an alternate 

mitigation measure that provides equivalent VOC reductions. 

The purpose of applying water to the surface of the windrow before turning during active 

composting is to capture the VOC emissions during turning, similar to a wet scrubber 
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effect, which helps capture water soluble pollutants. According to the field study, most 

VOCs from the composting process are water soluble. 

The proposed rule would also require the ball test, or squeeze test, as part of the 

watering system requirements to ensure that adequate water is applied to the compost 

pile before a turn and to address concerns with water run off and rain events. Although 

the ball test could also help operators determine the moisture level in a windrow, the 

purpose of the test is to show whether adequate amount of water has been applied prior 

to turning. 

According to the compost study and site visits to several facilities, a sprinkler system 

covers the top half of the pile and a water truck typically covers the entire pile. The 

proposed requirements would allow operators to conduct the ball test at least three 

inches in depth of the windrow and anywhere above the vertical midpoint to the peak of 

the windrow. 

District staff recognizes the different type of watering systems that could be applied at 

each of the composting operations and has provided two flexible categories for 

operators to satisfy rule requirements. The watering system is differentiated by two 

types of setup: one that is connected to a mechanical turner (integrated) and one that is 

separate from a mechanical turner (independent). 

Operators would be required to apply water to the windrow and test for adequate water 

within three hours of turning. If there is a rain event, operators would be able to test the 

windrow prior to watering. District staff has worked closely with the affected industry to 

gain firsthand knowledge and understanding of the different types of watering system 

and operations on site. Based on discussion with the operators, all of them would be 

able to comply with the proposed watering system requirements. 

Composting Operations with Total Throughput of 200,000 TPY or More and Less than 

750,000 TPY 

Revised Proposed New Rule 4566 would require operators of composting operations 

with total throughput of 200,000 wet tons per year or more and less than 750,000 wet 

tons per year of organic material to comply with both the watering system and the 

finished compost cover requirements for each windrow during the active phase of 

composting, or use an alternate mitigation measure which provides equivalent VOC 

reductions. The requirements for the watering system and finished compost cover 

would be implemented in a two-phase approach. The watering system requirements for 

this category would be the same as composting operations with total throughput below 

200,000 tpy and operators would be required to comply with the requirements after one 

year of rule adoption. For the finished compost cover requirements, the compliance 

schedule would be five years after rule adoption to allow time for operators to develop 

and implement an effective control strategy. Operators would be required to cover the 

windrow after formation and after the first three turns. The finished compost cover 

should be applied with at least six inches at the peak of the pile. This will create a 
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natural fall with some materials tapering over the upper third of the windrow, similar to 

the study. According to demonstrations at two facilities, the finished compost cover 

could taper over the upper half of the windrow; however, the draft rule requirements 

would require at least the top third to be covered to be more closely aligned with the 

compost study. Based on the study, the proposed rule would require that the entire 

length of the windrow be covered with a minimum of six inches in height of finished 

compost cover at the peak of each windrow. 

District staff has revised the language for the finished compost cover requirements from 

the July 19, 2011 version of the proposed rule for clarification purposes. The concepts 

and requirements have not changed due to the revision. 

The finished compost cover is made up of pre-screened finished compost and may 

include a mixture of screened finished compost or overs. According to the field study, 

the finished compost cover can be used to control emissions effectively and yielded the 

highest amount of reductions in VOC compared to other mitigations measures that were 

studied. 

District staff has also worked with the composting industry to address feasibility and 

costs of implementing of the finished compost cover requirements, which are further 

explained in Appendix C of this staff report. Based on District’s analysis and information 

received from the operators, it is not feasible for composting operations with less than 

200,000 tpy to implement the finished compost cover due to the size of the operation in 

relation to the cost of the equipment. However, District staff has found that one 

composting facility that has more than 200,000 tpy has been successfully implementing 

both the watering system and finished compost cover mitigation measures for several 

years. There are currently two operations above this limit, which make up over half of 

the total inventory for this source category. At this time, the second facility only has a 

watering system in place and is expected to increase its actual throughput in the next 

few years. As mentioned, the schedule for implementing the finished compost cover 

would allow this facility more time to develop and implement an effective control 

strategy. 

Composting Operations with Total Throughput of 750,000 TPY or More 

Revised Proposed New Rule 4566 would require the operator of a composting 

operation with a total throughput of greater than or equal to 750,000 wet tons per year 

of organic material to implement an APCO approved mitigation measure that 

demonstrates at least 80% reduction, by weight, in VOC emissions for organic material 

undergoing the active phase of composting. At this time, there are no composting 

operations in the SJVAB that are above this limit. However, the District would 

recommend more stringent controls should composting operations exceed such limit in 

the future. For example, there is one facility that could potentially exceed this limit in the 

future based on permitted throughput information. 
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Given the various emissions control technologies that are available and technologies 

that may become available in the future, operators would comply with the 80% reduction 

requirements through working with the District after rule adoption on an APCO approved 

mitigation measure. As a result, this rule would not specify any additional requirements 

for this category. 

5. Section 6.0 Administrative Requirements

Section 6.0 includes administrative requirements for implementing the mitigation 

measures, administrative requirements for an alternative mitigation measures 

compliance plan, recordkeeping requirements, and information on test methods. District 

staff also included TMECC Method 05-08-A (SOUR: Specific Oxygen Uptake Rate) for 

testing the compost maturity/stability of the composting phase, which would be 

consistent with other air district’s requirement for a direct respirometry. 

Section 6.1 for the facility emission mitigation plan also requires that operators submit 

an Authority-to-Construct (ATC) application. The requirements to obtain an ATC are 

governed by District Rule 2010, where the District has always required the submittal of 

an ATC application if there are changes to permit conditions even though no physical 

changes are warranted with the modification. However, the District will look into 

determining ways to expedite the permitting processing that fits the permit modifications 

for composting operations subject to this rule. 

6. Section 7.0 Compliance Schedule 

Table 4 and Table 5 shows the compliance schedule for composting operations subject 

to this rule. 

Table 4: Compliance Schedule for Facility Emission Mitigation Plan (FEMP) and 

Authority-to-Construct (ATC) Application

Requirements Compliance 

Schedule 

Watering system requirements or an APCO approved 

alternative mitigation measure that demonstrates at least 19% 

reduction, by weight, in VOC emissions. 

(six (6) months prior to 

full compliance) 

Finished compost cover requirements, along with the watering 

system requirements. In lieu of complying with both of the 

finished compost cover and watering system requirements, 

implement an APCO approved alternative mitigation measure 

that demonstrates at least 60% reduction, by weight, in VOC 

emissions. 

(one (1) year prior to 

full compliance) 

APCO approved mitigation measure that demonstrates at 

least 80% reduction, by weight, in VOC emissions for organic 

material during the active phase. 

(one (1) year prior to 

full compliance) 
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Table 5 – Compliance Schedule 

Facility Size Proposed Rule Requirements 

Compliance 

Period 

(Year After Rule 

Adoption Date) 

Composting Requirements During Active Composting 

Throughput < 200K tpy • Implement a watering system, or 

• Implement an alternative One Year 

200K tpy ≤ Throughput < 

750K tpy 

• Implement a watering system and 

finished compost cover, or 

• Implement an alternative 

One Year for the 

watering system 

and Five Years for 

the finished 

compost Cover 

Throughput ≥ 750K tpy 

• Implement an engineered control 

system, or 

• Implement an alternative 

Five Years 

Stockpile Requirements 

Throughputs < 100,000 

tpy 

Within 10 days, 

• Remove organic material from the 

facility or 

• Compost the organic material, or 

• Cover the material or 

• Implement an alternative 

One Year 

Throughputs ≥ 100,000 

tpy 

Within 3 days, 

• Remove organic material from the 

facility or 

• Compost the organic material or 

• Cover the material or 

• Implement an alternative 

One Year 

 

IV. BASELINE INVENTORY AND EMISSION REDUCTIONS 

Based on data, District staff estimates emission reductions of approximately 4.2 tons 

per day (1,518 tons per year) or a total reduction of 30% of the baseline VOC emissions 

after full implementation of the rule requirements. When the revised emission inventory 

baseline reductions (overall of 30%) are applied to the 2017 Ozone Plan baseline 

emissions, the equivalent reduction is 19 tons per day by the time that this rule is fully

implemented, which equates to achieving an additional reduction of 9 tons per day of 

VOC emissions from the source category. The VOC emission reduction analysis is 

included in Appendix B of the Final Staff Report. 
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V. COSTS AND COST EFFECTIVENESS ANALYSIS 

The purpose of conducting a cost effectiveness analysis is to evaluate the economic 

reasonableness of the pollution control measure or rule. The analysis also serves as a 

guideline in developing the control requirements. District staff has evaluated costs and 

cost effectiveness for composting operations affected by Revised Proposed New Rule 

4566. 

District staff has conducted several discussions and meetings with affected operators 

and composting representatives to refine the cost estimates. For composting 

operations that are subject to the watering system requirements, the cost effectiveness 

is about $390 per ton VOC reduced. For composting operations subject to both the 

watering system and finished compost cover requirements, the cost effectiveness 

ranges from about $2,393 to $2,525/ton of VOC reduced. 

Please see Appendix C of the final staff report for District staff’s analysis of the costs 

and cost effectiveness of the mitigation measures. 

VI. SOCIOECONOMIC ANALYSIS 

Pursuant to CH&SC 40728.5, District staff is required to analyze the socioeconomic 

impacts of any proposed rule or rule amendment that significantly affects air quality or 

strengthens an emission limitation. District staff held a socioeconomic focus group 

meeting for this rule development project in September 2010. District staff has worked 

with the stakeholders to determine direct compliance costs of the mitigation measures. 

A final socioeconomic analysis report is available as part of Appendix D for public 

review and has been updated to incorporate stakeholder’s comments. District staff used 

the socioeconomic analysis to refine the rule concepts, as appropriate, and to mitigate any 

adverse effects to the extent feasible and reasonable. District staff presented the final 

socioeconomic report to the District Governing Board at the public hearing in August 

2011, along with the revised proposed rule package, in order to disclose any expected 

economic impacts. 

VII. GLOBAL CLIMATE CHANGE 

Briefly stated, global climate change (GCC) is the cumulative change in the average 

weather of the earth that may be measured by changes in temperature, precipitation, 

storms, or wind. Global Climate Change is now generally accepted by the scientific 

community to be occurring and caused by “greenhouse gases” (GHG). Greenhouse 

gases are gases which allow direct sunlight (relative shortwave energy) to reach the 

Earth's surface unimpeded. As the shortwave energy (that in the visible and ultraviolet 

portion of the spectra) heats the surface, longer-wave (infrared) energy (heat) is 
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reradiated to the atmosphere. Greenhouse gases absorb this energy, thereby allowing 

less heat to escape back to space, and 'trapping' it in the lower atmosphere. 

The scientific and political communities in the State of California have collectively 

concluded that a significant and growing scientific body of evidence supports the need 

for regulating GHG emissions. The California Global Warming Solutions Act of 2006 

(AB 32) created a comprehensive, multi-year program to reduce GHG emissions in 

California, to 1990 levels by the year 2020. 

The District believes that the evidence and the rationale that climate change is occurring 

is compelling and convincing. In addition to the long-term consequences of climate 

change, the District is concerned with the potential ramifications of more moderate but 

imminent changes in weather patterns. The Valley depends heavily on agriculture for its 

economy and has developed agricultural practices based on the last several decades of 

weather patterns. Unanticipated and large fluctuations in these patterns could have a 

devastating effect on the Valley’s economy. 

While there are many win-win strategies that can reduce both GHG and criteria/toxic 

pollutant emissions, when faced with situations that involve tradeoffs between the two, 

District staff believes that the more immediate public health concerns that may arise 

from an increase in criteria or toxic pollutant emissions should take precedence. 

A. Greenhouse Gases and Atmospheric Chemistry 

Some greenhouse gases such as water vapor occur naturally and are emitted to the 

atmosphere through natural processes as well as through human activities. The most 

common GHG that results from human activity is carbon dioxide, followed by methane 

and nitrous oxide. GHGs can include: water vapor, ozone, aerosols, 

chlorofluorocarbons, carbon dioxide, methane, nitrous oxide, and fluorinated gases 

(such as hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride). 

Recent studies support a conclusion that global warming is also affected by changes in 

tropospheric ozone (O3). Tropospheric ozone is both generated and destroyed by 

photochemistry within the atmosphere. Volatile organic compounds (VOC) and nitrogen 

oxides (NOx) are two pollutants which form tropospheric ozone through photochemical 

reactions. Decreasing these pollutants within the atmosphere reduces formation of 

tropospheric ozone and thus, has an indirect, positive influence on global climate 

change. 

B. Composting Impacts 

Natural decomposition of organic matter occurs from both nonbacterial (abiotic) and 

bacterial (biotic) processes. Biotic processes transform carbon into cellular mass but 

result in waste gas emissions of carbon dioxide, methane and nitrous oxide. 

Composting accelerates the biotic process which results in more rapid emission of 
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VOC, CO and methane. The speed of emission is not significant as a global warming 

issue since the material will break down with or without composting. The speed is 

important for ozone formation as this could potentially result in higher daily 

concentrations of tropospheric ozone. 

Composting is viewed as having an environmental benefit as compared to natural 

decomposition. Natural decomposition of materials left in place to decay is relatively 

inefficient and releases more gaseous emissions into the air. The effect of piling the 

material in the composting process delays release of gases into the air and allows more 

bacterial activity that turns these gaseous emissions into stored carbon. As a global 

warming issue, the total amount of carbon released is to be considered. The amount of 

carbon in different forms is decreased by the amount processed by bacteria into cell 

matter. The United States Environmental Protection Agency (USEPA) has assessed the 

balance between the cellular uptake and the amount of carbon emissions and nitrous 

oxide emissions. USEPA determined that the thirty year retention of carbon far 

outweighed the combined emissions of carbon and nitrous oxide converted into 

equivalents of carbon. 

VII. ENVIRONMENTAL IMPACTS 

A. Effects of Revised Proposed New Rule 4566 

Implementation of Revised Proposed New Rule 4566 is not expected to either increase 

or decrease the amount of composting activity that currently occurs within the San 

Joaquin Valley air basin. In that regard, the impact of rule implementation is 

environmentally neutral. 

As presented in the Emission Reduction Analysis, implementation of Revised Proposed 

New Rule 4566 is expected to reduce VOC emissions from composting by 1,518 

tons/year (4.2 tons/day). Reducing VOC emissions reduces formation of tropospheric 

ozone. Thus, implementation of the proposed VOC control measures would have an 

indirect, positive influence on global climate change. 

Implementation of certain control measures could result in increased fossil fuel use. The 

District estimates that increased fossil fuel use could result in a 1.4 tons/year increase in 

oxides of nitrogen (NOx), a 0.2 tons/year increase in VOC, a 0.1 tons/year increase in 

particulate matter 10 microns (PM10), and a 183 tons/year increase in CO2 emissions. 

B. Cumulative Impacts on Global Climate Change 

On February 16, 2010, the California Office of Administrative Law approved 

amendments to the California Code of Regulations, emphasizing that the effects of 

GHG are cumulative impacts and should be analyzed in the cumulative impacts 

analysis. To assist lead agencies in determining the significance of project related 
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greenhouse gas emissions a new subdivision was added to the CEQA Guidelines; 

Section 15064.4 (Determining The Significance of Impacts From Greenhouse Gas).

This section provides that when assessing cumulative significance of project specific 

GHG emissions on global climate change, a lead agency should consider, among other 

factors, the extent to which the project may increase or reduce greenhouse gas 

emissions as compared to the existing environmental setting. 

Quantification of potential changes in global climate change that may result from 

implementation of Revised Proposed New Rule 4566 requires a degree of speculation 

and conjecture that is inappropriate and discouraged under CEQA (CCR §15187(d)). 

From a qualitative perspective, the District concludes that overall reductions in VOC 

emissions and the concomitant reduction in tropospheric ozone formation outweigh 

potential increases in NOx emissions and CO2 emissions associated with increased 

fossil fuel consumption. 

The District finds that there is no substantial evidence, in light of the whole record 

before the District, that the project could have a cumulatively significant impact on 

global climate change. 

IX. RULE CONSISTENCY ANALYSIS 

Pursuant to California Health & Safety Code Section 40727.2, District staff has prepared 

a rule consistency analysis that identifies and compares the air pollution control 

elements of the Revised Proposed New Rule 4566 with the corresponding elements of 

other District, state, and federal regulations and guidelines that apply to the same 

source category. Staff found that facilities could comply with Rule 4566 and all existing 

District Rules. Furthermore, staff found that none of the requirements of Rule 4566 

would conflict with local, state, or federal rules, regulations, or policies. Please refer to 

Appendix E for further discussion on the analysis. 

X. REASONABLE AVAILABLE CONTROL TECHNOLOGY (RACT) 

Section 172(c)(1) of the federal Clean Air Act requires air quality plans for 

nonattainment areas to “provide for the implementation of all reasonable available 

control measures as expeditiously as practicable (including such reductions in 

emissions from existing sources in the area as may be obtained through the adoption, 

at a minimum, of reasonably available control technology (RACT)) and shall provide for 

attainment of the national primary ambient air quality standards.” RACT is also defined 

in the 2007 Ozone Plan as devices, systems, process modifications, or other apparatus 

or techniques that are reasonably available taking into account the necessity of 

imposing such controls in order to attain and maintain a national ambient air quality 

standard; the social, environmental, and economic impact of such controls; and 

alternative means of providing for attainment and maintenance of such standard. 
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In the greater context of air pollution control levels, RACT is understood as the “floorlevel” of air pollution controls, not the “ceiling-level.” More effective levels of emissions 

control are termed Best Available Control Technology (BACT) and Lowest Achievable 

Emission Rate (LAER). BACT and LAER are required for new sources, and for existing 

sources undergoing modification. Under state and federal air pollution programs, new 

facilities face more stringent pollution control requirements than existing facilities, with 

the understanding that better controls can be more easily implemented before a facility 

is built, than after it is built. New sources must generally implement BACT1 and existing 

sources must implement a less stringent level of control such as Reasonably Available 

Control Technology (RACT). Additionally, California law establishes an intermediate 

level of control that is the “best available” for “retrofit” to existing sources (entitled Best 

Available Retrofit Control Technology – BARCT2), recognizing that the state’s worst 

ozone problems demands more effective pollution control than what is usually 

considered “reasonably available.” 

The following section evaluates the requirements of Revised Proposed New Rule 4566 

in light of the above RACT and BARCT definition. 

How does District Rule 4566 compare with federal rules and regulations? 

A. EPA – Control Technique Guidelines (CTG) 

There is no EPA CTG guidance document for organic material composting operations. 

B. EPA - Alternative Control Technology (ACT) 

There is no EPA ACT guidance document for organic material composting operations. 

C. Standards of Performance for New Stationary Sources (NSPS) 

There is no NSPS guidance document for organic material composting operations. 

D. National Emission Standards for Hazardous Air Pollutants (NESHAPs) and 

Maximum Achievable Control Technologies (MACTs) 

There is no NSPS guidance document for organic material composting operations. 

 

1

 Federal regulations for permitting new facilities require Best Available Control Technology (BACT) for 

new sources in attainment areas, and Lowest Achievable Emission Rate (LAER) – a generally more 

stringent level –for new sources in nonattainment areas. LAER differs from BACT in that economic costs 

are not considered for candidate LAER controls that are considered “Achieved in Practice.” Under 

California state law, the District is required to apply “BACT” for new sources under essentially the same 

requirements as federal LAER. The District’s “BACT” determinations thus fulfill the federal LAER 

requirements. 

2

 California Health and Safety Code (CH&SC) 40406: ... "best available retrofit control technology" means

an emission limitation that is based on the maximum degree of reduction achievable, taking into account 

environmental, energy, and economic impacts by each class or category of source. 
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How does District Rule 4566 compare to rules in other air districts?

District staff compared VOC limits, optional control requirements, and work practice 

standards in District Rule 4566 to comparable requirements in rules from the following 

California nonattainment areas: 

• South Coast AQMD Rule 1133.3 – Emission Reductions from Greenwaste 

Composting Operations 

• Bay Area AQMD, Sacramento Metropolitan AQMD and Ventura County APCD do 

not have rules that apply to organic material composting operations. 

South Coast Air Quality Management District (SCAQMD) Rule 1133.3 (Emission 

Reductions from Greenwaste Composting Operations) 

South Coast AQMD recently adopted Rule 1133.3 on July 8, 2011. District staff has 

worked closely with SCAQMD staff to share information and rule concepts. Staff notes 

that there may be differences between District Rule 4566 and SCAQMD Rule 1133.3. 

This should not be interpreted to mean that one rule is more stringent than the other, 

but due instead to additional factors: 

1. South Coast AQMD is a VOC limited area and VOC emissions reductions have 

a greater impact towards Ozone attainment, whereas the San Joaquin Valley is 

a NOx limited area; 

2. The socioeconomic climate of the SCAQMD is significantly different from that of 

the District. 

District has also worked closely with the affected stakeholders to evaluate the available 

controls and determine the additional costs of implementing the controls. Based on the 

District’s cost-effectiveness analysis in Appendix C, it would not be economically 

feasible for operators to implement more stringent controls than what is already 

proposed in the rule. The cost to implement more stringent controls, such as 

engineered systems, would more than triple the cost for these operators. In addition, 

the results from the District’s socioeconomic report shows that the proposed 

requirements, specifically the finished compost cover, would have an economic impact 

on at least one of the composting facility. Please refer to Appendix C and Appendix D 

for further discussion on the cost-effectiveness and socioeconomic analyses. 

After careful evaluation of federal and California regulations and the technological and 

economical feasibility of potential mitigation measures, District staff concludes that new 

Rule 4566 would satisfy, if not go beyond, RACT and BARCT requirements for this 

source category based on the same required evaluation. 
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XI. CURRENT VOC REGULATION BY MASS AND ALTERNATIVE REGULATION 

BY OZONE CONTRIBUTION 

EPA requires compliance efforts for the ozone standard to be established in terms of 

the mass of emissions reduced. The District has recommended to EPA that flexibility 

be provided to consider and prioritize reductions that have the most benefit in reducing 

ozone emissions and subsequently reduce population exposure, with greater credit 

provided for reductions in Environmental Justice communities. Until such time as EPA 

considers and makes regulatory adjustments in response to this District request, the 

mass based approach remains the regulatory requirement. 

A. Explanation of the Regulatory Approach 

The District regulates on a mass, or weight, basis all volatile organic compound (VOC) 

emissions that have been determined by EPA to have more than a minimal contribution 

to harmful ozone in the air we breathe. District permits, regulations and compliance 

tests establish limits for VOC emissions that are based on the mass of emissions 

emitted, excluding only those compounds that EPA accepts as having little or no impact 

on formation of harmful ozone. The value of excluding the minimal contributing 

compounds is to encourage source types which have the ability to reformulate their 

materials or emissions to use minimal ozone forming compounds in replacement of 

compounds that form greater amounts of ozone. 

B. Alternative to Current Regulatory Approach 

EPA acknowledges that assessing the amount of ozone formed by each compound 

(defined as atmospheric reactivity) could be used as an alternative basis for regulation 

instead of using just the amount of emissions (by weight or mass); however, if this 

approach were to be adopted, associated with the alternative approach there are 

additional requirements, proofs, and evaluations required for the District and the state, 

and different compliance requirements for operators. 

The alternative regulatory approach is referred to as a “reactivity” approach because the 

method is based on assessing how much a specific VOC compound reacts in the 

atmosphere either to form ozone or increase the amount of ozone formed by other 

compounds. The “reactivity” value is multiplied by the amount (by mass or weight) to 

determine the full impact of the emitted material on a basis that accounts for both the 

amount of emission and the different relative contribution to formation of ozone. 

There are thousands of different VOC compounds and each has a different contribution 

to the harmful ozone, either directly or by influencing the amount of ozone formed by 

other compounds. The difficulty in establishing the appropriate value for each 

compound, changing regulations to require measurement and permitting by compound, 

and required supporting evaluations and approvals by EPA and ARB preclude this as a 

viable approach for the District at this time. 
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ARB has established reactivity values for the reformulation of architectural coatings and 

has received approval for this regulatory approach for that category of emissions. 

Approval to regulate the specific source category with the reactivity approach required 

removal of the exemption for minimally ozone forming compounds for these sources. 

The requirements for the District to pursue a similar approach for a specific regulation or 

for all District regulations are extensive. 

C. Value of VOC Specific Compound Data 

The District recognizes the value of measuring emissions from each source type as 

accurately as possible, including the identification of specific VOC compounds and 

amounts. The current use for this information is to update the emission inventory 

identification of compounds emitted by a source type, referred to as the speciation 

signature for a source. Speciation signatures are used in regional modeling for 

photochemical assessment of the effect of growth trends and emission controls. The 

modeling projections predict future ozone levels and assist in developing plans 

designed to achieve the health based federal ozone standards. Speciated 

measurement of emissions is not routinely required for most sources due to the 

technical difficulty and expense for obtaining data at this level of detail. 

The additional potential value of the speciation data and assessment of ozone reactivity 

is to identify compounds that have minimal ozone contribution and may be considered 

for de-listing by EPA. De-listing would remove the requirement for the compound to be 

limited and regulated. Such assessments must be done carefully and in accordance 

with nationally recognized protocols. Not only must the contribution to ozone be 

considered, but also the potential for the VOC compound to contribute to formation of 

fine particulate matter (PM2.5). Particulate formed in the atmosphere from VOC 

emission is called secondary organic aerosol (SOA). SOA is PM2.5 that must be 

regulated to achieve the federal health based standard for fine particulate matter. 

D. Applicability to Compost Emission Regulation 

District rule development for regulation of VOC from composting operations will rely on 

the current mass basis used for all District regulations. While information on the relative 

ozone forming contribution of different VOC compounds emitted by compost operations 

is of interest and value for proper characterization of the impact of these emissions on 

regional ozone levels, such data would not constitute a sufficient basis for the District to 

establish regulatory requirements to focus on specific emitted compounds. Even if a 

specific compound was identified as more reactive than other compounds emitted in the 

composting operation, the District lacks sufficient technical foundation to establish a 

specific change to composting procedures that would eliminate or reduce any specific 

VOC compound. 
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XII. REFERENCES

1. California Code of Regulations, Title 14, Division 7, Chapter 3.1 available at 

http://www.ciwmb.ca.gov/Regulations/Title14. 

2. California Code of Regulations, Title 27, Division 2 available at 

http://www.ciwmb.ca.gov/Regulations/Title27/. 

3. San Joaquin Valley Unified Air Pollution Control District Rule 4565, Rule 4565 Staff Report 

and Appendices. 

4. SCAQMD Rule 1133, staff report, and technology assessment.

5. SJVUAPCD 2007 Ozone Plan

6. California Department of Resources Recycling and Recovery, Strategic Directive 6 , 

available at: http://www.calrecycle.ca.gov/AboutUs/StrategicPlan/2009/SD06.htm

7. ENVIRONMENTAL PROTECTION AGENCY, 40 CFR Part 51, Section V, “Interim Guidance 

on Control of Volatile Organic Compounds in Ozone State Implementation Plans.” 

8. Reactivity Research Working Group (RRWG), Section 2.1.3.1 Impacts of Volatility 

Thresholds and Test Methods, “VOC Reactivity Policy White Paper,” October 1, 1999. and 

ENVIRONMENTAL PROTECTION AGENCY, 40 CFR Parts 51 and 52, 6560-50-P, 

“Revisions to the California State Implementation Plan and Revision to the Definition of 

Volatile Organic Compounds (VOC) - Removal of VOC Exemptions for California’s Aerosol 

Coating Products Reactivity-based Regulation.” 

9. ENVIRONMENTAL PROTECTION AGENCY, 40 CFR Part 51, Section IV and V, “Interim 

Guidance on Control of Volatile Organic Compounds in Ozone State Implementation Plans.” 

10. ENVIRONMENTAL PROTECTION AGENCY, 40 CFR Parts 51 and 52, 6560-50-P, 

“Revisions to the California State Implementation Plan and Revision to the Definition of 

Volatile Organic Compounds (VOC) - Removal of VOC Exemptions for California’s Aerosol 

Coating Products Reactivity-based Regulation.” 

11. Reactivity Research Working Group (RRWG), Section 4.2.3.2 Control Measure Design and 

Implementation, “VOC Reactivity Policy White Paper,” October 1, 1999. 

12. UNITED STATES ENVIRONMENTAL PROTECTION AGENCY: SOLID WASTE 

MANAGEMENT AND GREENHOUSE GASES, A Life-Cycle Assessment of Emissions and 

Sinks, 3rd EDITION, September 2006. 

13. California Air Resources Board, Composting issues website: 

http://www.arb.ca.gov/cc/compost/compost.htm

14. California Air Resources Board, Climate Change Proposed Scoping Plan Appendices, 

VOLUME I: SUPPORTING DOCUMENTS AND MEASURE DETAIL, measure RW-3, C161, 

October 2008. http://www.arb.ca.gov/cc/scopingplan/document/appendix1.pdf 

15. California Air Resources Board “PROPOSED METHOD FOR ESTIMATING GREENHOUSE 

GAS EMISSION REDUCTIONS FROM COMPOST FROM COMMERCIAL ORGANIC 

WASTE,” August 31, 2010 

16. San Joaquin Valleywide Air Pollution Study Agency [SJVAPSA]. (2011). Comparison of 

Mitigation Measures for Reduction of Emissions Resulting from Greenwaste Composting. 

Fresno, CA: San Joaquin Valleywide Air Pollution Study Agency. Retrieved from 

http://www.valleyair.org/busind/pto/emission_factors/Criteria/Criteria/Composting/Compost%

20Study%20Draft%20Report.pdf (Report) and 

http://www.valleyair.org/busind/pto/emission_factors/Criteria/Criteria/Composting/Compost%

20Study%20Appendices.pdf (Appendices)