SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Appendix B: Emission Reductions Analysis August 18, 2011 

B - 1 Final Staff Report with Appendices 

For Revised Proposed New Rule 4566

APPENDIX B 

Emission Reductions Analysis 

For Revised Proposed New Rule 4566 

August 18, 2011 

 
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Appendix B: Emission Reductions Analysis August 18, 2011 

B - 2 Final Staff Report with Appendices 

For Revised Proposed New Rule 4566

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SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Appendix B: Emission Reductions Analysis August 18, 2011 

B - 3 Final Staff Report with Appendices 

For Revised Proposed New Rule 4566

EMISSION REDUCTION ANALYSIS FOR 

PROPOSED NEW RULE 4566 (ORGANIC MATERIAL COMPOSTING OPERATIONS)

I. SUMMARY 

This appendix details the estimated volatile organic compounds (VOC) emissions and 

emission reductions for Revised Proposed New Rule 4566 (Organic Material 

Composting Operations). Revised Proposed New Rule 4566 would begin achieving 

emissions reductions in 2012, with full implementation starting in 2016. 

In the course of rule development for Rule 4566, the District found that the total 

emissions inventory for the Composting-Greenwaste category is much smaller than 

estimated in the 2007 Ozone Plan. However, the District also found that there is a

much greater emissions reduction percentage than previously estimated. Table 1 

summarizes the baseline inventory and reductions from the 2007 Ozone Plan as 

compared to the inventory compiled during the development of Rule 4566. The actual 

percent reduction from the rule can be applied to the plan baseline to determine the 

estimated reductions as a “SIP currency” equivalent. Section III of this appendix 

provides more detail on this data and calculations. 

Table 1: Summary of Composting VOC Emissions and Emission Reductions

Year Inventory 

Estimated 

baseline 

emissions 

(tons/year) 

Estimated 

emissions 

after control 

(tons/year) 

Estimated VOC 

emission 

reductions 

(tons/year) 

Percent 

reduction 

2012 

2007 Ozone Plan 20,805 17,520 3,285 16% 

Updated, Rule 4566 5,064 3,799 1,265 25%1

Revised reductions, SIP currency equivalent. 

Apply Rule 4566 percent reduction to 2007 

Ozone Plan baseline. 

5,201 

 (14 tons per day) 

2017 

2007 Ozone Plan 23,360 19,710 3,650 16% 

Updated, Rule 4566 5,064 3,546 1,518 30%2

Revised reductions, SIP currency equivalent. 

Apply Rule 4566 percent reduction to 2007 

Ozone Plan baseline. 

7,008 

 (19 tons per day) 

1. 2012 emission reductions include stockpile and watering system requirements after one year of 

rule adoption date. The emission reductions from one facility that is subject to the finished 

compost cover requirements and is already implementing the finished compost cover is included. 

2. 2017 emissions reductions include all requirements after five years of rule adoption date. 
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Appendix B: Emission Reductions Analysis August 18, 2011 

B - 4 Final Staff Report with Appendices 

For Revised Proposed New Rule 4566

The 2007 Ozone Plan estimated an emission reduction for the Composting Green 

Waste (S-GOV-5) control measure of 16% from the Plan baseline, upon final 

implementation of the rule requirements. The estimates are based on the best available 

information at the time that this report was written. Based on the updated data, District 

staff estimates emission reductions of approximately 1,265 tons per year (tpy) or a 

reduction of 25% of the baseline VOC emissions by 2012. The emissions reduction that 

would be achieved by 2012 include all facilities that would be implementing the watering 

system and the facility that is already in compliance with both the watering system and 

finished compost cover requirements. 

When the 2010 emission inventory baseline reductions (overall of 30%) are applied to 

the 2017 Ozone Plan baseline emissions of 23,360 tons per year, the equivalent 

reduction is 19 tons per day by the time that this rule is fully implemented. The 

emission reductions that would be achieved with the Revised Proposed New Rule 4566 

requirements exceed the projected reductions in the 2007 Ozone Plan and would also 

meet RACT. 

II. INTRODUCTION 

The purpose of Revised Proposed New Rule 4566 is to control VOC emissions from 

composting facilities. This rule applies to facilities involved with the composting or 

stockpiling of organic materials. Operators would be required to control the VOC 

emissions from their organic material stockpiles and composting piles. Operators will 

have the option to utilize the rule-required control measures or alternative control 

measures that demonstrate equivalent VOC emission reductions. For this emissions 

reduction analysis, the breakdown of carbon-based chemicals by microorganisms in the 

organic material is the source of VOC emissions. Section III of this appendix details the 

calculations for the estimated emissions and emission reductions. 

III. EMISSION REDUCTION ANALYSIS

A. Throughput Calculations 

Throughout the rulemaking process, District staff has researched and acquired available 

data for the organic material throughput for green material facilities. District staff has 

involved stakeholders in this process to obtain the best estimates for the amount of 

organic material that is generated in and imported into the San Joaquin Valley Air Basin 

(SJVAB) for the 2010 source inventory. Staff will continue to refine the analysis as new 

information and data becomes available during the rule development process. 

In November 2007, the District distributed applications to all organic material processing 

facilities within the SJVAB to determine permit status. More recently, District staff has 
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Appendix B: Emission Reductions Analysis August 18, 2011 

B - 5 Final Staff Report with Appendices 

For Revised Proposed New Rule 4566

worked with the facilities to update and refine the source inventory with 2010 data for a 

more accurate analysis. 

An inventory was identified for organic material composting using the following sources: 

• CalRecycle’s Solid Waste Information System (SWIS) (available online at 

http://www.calrecycle.ca.gov/SWFacilities/Directory/) 

• Lists of green material facilities, submitted by CalRecycle in November 2007 and 

January 2008 

• Public comment letters 

• Stakeholders’ comments and facility information 

• The District Permit to Operate database 

• Completed PTO applications 

An estimated throughput of the facilities within the District’s three regions is provided in 

Table 2. The Northern Region consists of facilities located within San Joaquin County, 

Stanislaus County, and Merced County. The Central Region consists of the facilities 

located within Madera County, Fresno County, and Kings County. The Southern 

Region consists of facilities located within Tulare County and Kern County. For the 

purpose of this rule development project, District staff used the actual throughput to 

conduct the emissions analysis. The potential throughput is the maximum permitted 

throughput and is used for the permitting process through the District’s Permit Services 

Department. Some composting facilities that are currently operating and not included in 

the District’s regional totals in Table 2 are co-composting facilities and are already 

subject to District Rule 4565 requirements. 

Table 2: Composting Facilities Organic Material Throughputs 

Region Actual Throughputs1 (Tons/Year) 

Northern 435,678 

Central 131,798 

Southern 490,707 

TOTAL 1,058,183

1. Actual Throughputs: based on 2010 data from operators. 

The estimates from Table 2 were used to determine the emissions and emissions 

reduction for composting facilities. 
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Appendix B: Emission Reductions Analysis August 18, 2011 

B - 6 Final Staff Report with Appendices 

For Revised Proposed New Rule 4566

B. Emission Factors 

In May 2008, the District hired a consultant to review and analyze all available 

emissions factors from several source tests for green material composting. A copy of 

the District’s Compost VOC Emission Factors report can be found at the following link: 

http://www.valleyair.org/Workshops/postings/2010/9-22-10-

rule4566/SJVAPCD%20Compost%20VOC%20EF%20Report%209-15-10.pdf

 

The District has not identified relevant emission factors for uncontrolled food material 

composting. Source tests from controlled composting operations have yielded emission 

factors ranging from 3.4 lb VOC per ton of food material composted (micropore cover) 

to 37.1 lb VOC per ton of food material composted (Ag Bag). In addition to the wide 

range of values observed, it is also unlikely that emissions from a covered system would 

accurately represent emissions from the open windrow commonly used by facilities in 

the District. This is because covered systems offer many process control advantages, 

including weather protection and water retention. For these reasons, the District will 

use the green material composting emission factors as determined in the preliminary 

Green Waste Compost Report to represent this feed stock until a more representative 

emission factor can be identified. 

The Composting VOC Emission Factors report presents the emission factors that the 

District will use for permitting and rule development purposes. The emission factors 

used for all calculations are presented in Table 3, below. The emission factors 

presented are subject to revision should additional information become available. 

Table 3: Emission Factors (EF)

Process Type Stockpile EF 

(lb/ton/day) 

Active Phase Windrow 

Composting EF 

(lb/ton processed) 

Curing Phase Windrow 

Composting EF 

(lb/ton processed) 

Organic material 1.06 5.14 0.57 

C. Emission Reduction Efficiencies Used 

Stockpile Operations 

The stockpile VOC emission reduction efficiency was estimated from the composting 

facilities typical stockpile storage times and the proposed rule required maximum threeday or ten-day stockpile storage time. The resulting VOC emission reduction efficiency 

will be used for this analysis as listed below: 

• Maximum Three-Day Stockpile Storage Time: Consists of removing, covering, 

or composting the stockpiled organic materials within three days of receipt. This 

option would limit the storage time for the composting operation with an organic 

material receiving volume of greater than or equal to 100,000 tpy. 
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Appendix B: Emission Reductions Analysis August 18, 2011 

B - 7 Final Staff Report with Appendices 

For Revised Proposed New Rule 4566

• Maximum Ten-Day Stockpile Storage Time: Consists of removing, covering, or 

composting the stockpiled organic materials within ten days of receipt. This 

option would provide a significant emission reduction for composting opration 

with an organic material receiving volumes of less than 100,000 tpy. 

Composting Operations 

District staff has reviewed the results from the 2009 compost field study conducted by 

the San Diego State University Research Foundation. The field study assessed the 

feasibility and effectiveness of VOC emission reductions from four mitigation measures. 

Two of the most effective mitigation measures identified in the field study were used for 

the composting operations analysis and are listed below: 

• Watering System: Operator applies water to the windrows before each turn. The 

VOC reduction efficiency for this mitigation measure is determined to be at least 

19% by weight during active composting, as defined in the proposed rule. 

• Finished Compost Cover: Operator applies a minimum 6-inch layer of finished 

compost on top of the windrows after each turn. The VOC reduction efficiency 

for this mitigation measure is determined to be at least 56% by weight during 

active composting, as defined in the proposed rule. 

The watering system requirements would apply to a composting operation with an 

organic material receiving volume of less than 200,000 tpy. For a composting operation 

with an organic material receiving volume of greater than or equal to 200,000 tpy and 

less than 750,000 tpy, the operator would be required to comply with both the watering 

system and the finished compost cover requirements. As show below, the District staff 

has derived a VOC control efficiency factor for implementing both the watering system 

and finished compost cover during active composting. 

The maximum combined control efficiency would assume the control systems do not 

lose any of their individual effectiveness when combined. However, since there is no 

supporting data for this, the combined control efficiency will be discounted. Without 

actual test data on the combined controls, a 50% factor has been chosen and will be 

applied to the increase in control due to the combined controls. Due to the nature of the 

controls, the District does not expect the effectiveness of a control to lose more than 

50% of its effectiveness when combined with another. As such, the District is 

comfortable with a 50% factor applied to the increase as a conservative estimate. 

By using the individual control efficiencies from the mitigation measures above, the 

maximum combined VOC control efficiency resulted in at least 64% by weight of the 

material, calculated as follows: 
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Appendix B: Emission Reductions Analysis August 18, 2011 

B - 8 Final Staff Report with Appendices 

For Revised Proposed New Rule 4566

Combined VOC control efficiency = 56% + [(1 - 56%) x 19%] = 64%

Where: 56% = VOC control efficiency for the finished compost cover 

 19% = VOC control efficiency for the watering system 

As stated above, the increase in VOC control efficiency from combining the mitigations 

measures will be conservatively reduced by 50% as follows:

Increase in control due to combining controls = 64% - 56% = 8% 

Where: 64% = Maximum Combined VOC control efficiency 

 56% = VOC control efficiency for the finished compost cover

Final Combined VOC control efficiency = 56% + (8% x 50%) = 60%

The combined VOC control efficiency of implementing both the finished compost cover 

and watering system during active composting is therefore 60%. 

D. Emission and Reduction Calculations 

In performing the analyses, several assumptions were made to estimate the emission 

reductions. These include: 

• All of the existing composting facilities would implement the proposed mitigation 

measures or an equivalent alternative mitigation measure, based on the facility 

throughput limit. 

• Emission reductions from composting operations with an organic material 

receiving volume of less than 100,000 tpy are based on implementing the 

watering system and the maximum ten-day stockpile storage time mitigation 

measures. 

• Emission reductions from composting operations with an organic material 

receiving volume of greater than or equal to 100,000 tpy and less than 200,000 

tpy are based on implementing the watering system and the maximum three-day 

stockpile storage time mitigation measures. 

• Emission reductions from composting operations with an organic material 

receiving volume of greater than or equal to 200,000 tpy and less than 750,000 

tpy are based on implementing the watering system, finished compost cover and 

the maximum three-day stockpile storage time mitigation measures. 
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Appendix B: Emission Reductions Analysis August 18, 2011 

B - 9 Final Staff Report with Appendices 

For Revised Proposed New Rule 4566

• Emission reductions from composting operations with an organic material 

receiving volume of greater than or equal to 750,000 tpy are based on 

implementing the watering system, finished compost cover and the maximum 

three-day stockpile storage time mitigation measures. 

Stockpile and Composting Operations 

Using the throughput information from the operators, staff calculated the estimated 

actual VOC emissions using the following equations:

Actual Stockpile VOC Emissions (tpy) = [Throughput (tpy) × Stockpile Storage Time (days) 

× Stockpile EF (lb/ton/day)] ÷ 2,000 lb/ton 

Actual Windrow VOC Emissions (tpy) = [Throughput (tpy) × (Active Phase Windrow EF (lb/ton) 

 + (Curing Phase Windrow EF (lb/ton))] ÷ 2,000 lb/ton 

Total Current VOC Emissions (tpy) = Actual Stockpile VOC Emissions (tpy) 

 + Actual Windrow VOC Emissions (tpy) 

Where: Throughput = Facility throughput in tons per year 

 Stockpile Storage Time = Facility stated stockpile storage time in days. 

 Stockpile EF = 1.063 lb/ton/day 

 Active Phase Windrow EF = 5.14 lb/ton 

 Curing Phase Windrow EF = 0.57 lb/ton 

 2,000 lb/ton = Conversion factor 

The VOC emissions resulting from the mitigation measures identified in Section III.C. 

above will be calculated using the following equation: 

Stockpile Emissions After Reductions (tpy) = [Throughput (tpy) × 3-day Stockpile Storage Time 

or Facility’s Storage Time, which ever is less 

× Stockpile EF (lb/ton/day)] ÷ 2,000 lb/ton 

Stockpile Emissions After Reductions (tpy) = [Throughput (tpy) × 10-day Stockpile Storage 

Time or Facility’s Storage Time, which ever is 

less 

× Stockpile EF (lb/ton/day)] ÷ 2,000 lb/ton 

Active Phase Emissions After Reductions (tpy) = [Throughput (tpy) × (Active Phase EF (lb/ton) 

× (1 – CE)] ÷ 2,000 lb/ton 

Curing Phase Emissions After Reductions (tpy) = [Throughput (tpy) × (Curing Phase EF (lb/ton) 

× (1 – CE)] ÷ 2,000 lb/ton 

Total Emissions After Reductions (tpy) = Stockpile Emissions After Reductions (tpy) 

 + Active Phase Emissions After Reductions (tpy) 

 + Curing Phase Emissions After Reductions (tpy) 
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Appendix B: Emission Reductions Analysis August 18, 2011 

B - 10 Final Staff Report with Appendices 

For Revised Proposed New Rule 4566

Where: Throughput = Facility throughput in tons per year 

 Stockpile EF = 1.063 lb/ton/day 

 Active Phase Windrow EF = 5.14 lb/ton 

 Curing Phase Windrow EF = 0.57 lb/ton 

 CE = Percentage reductions from the mitigation measure. 

 2,000 lb/ton = Conversion factor 

Table 4 shows the estimated current VOC emissions from composting facilities within 

the District. 

Table 4: Total Current VOC Emissions from Composting Facilities

Throughput 

Number 

of 

Facilitie

s 

Estimated 

Throughput 

(tpy) 

Stockpile 

Emissions 

(tpy) 

ActivePhase 

Emissions 

(tpy) 

CuringPhase 

Emissions 

(tpy) 

Total 

Current 

Emissions 

(tpy) 

throughput < 100,000 tpy 13 397,457 1,551 1,021 113 2,685 

100,000 tpy ≤ throughput < 200,000 tpy 1 103,108 110 265 29 404 

200,000 tpy ≤ throughput < 750,000 tpy 2 557,618 384 1,432 159 1,975 

throughput > 750,000 tpy N/A 0 0 0 0 0 

Total 16 1,058,183 2,045 2,718 301 5,064
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Appendix B: Emission Reductions Analysis August 18, 2011 

B - 11 Final Staff Report with Appendices 

For Revised Proposed New Rule 4566

Table 5 shows the estimated VOC emissions after reductions from composting facilities 

within the District. 

Table 5: Total VOC Emission After Reductions from Composting

Throughput 

Classification 

Number of 

Facilities 

Estimated 

Throughput 

(tpy) 

Stockpile 

Emissions 

(tpy) 

Active-Phase 

Emissions 

(tpy) 

Curing-Phase 

Emissions 

(tpy) 

Total Emissions 

After Reductions 

(tpy) 

throughput < 

100,000 tpy 

13 397,457 1,136 

(Control) 

 827 

(19% Control) 

113 

(No Control) 

2,076 

100,000 tpy ≤

throughput < 

200,000 tpy 

1 103,108 110 

(Control) 

 215 

(19% Control) 

29 

(No Control) 

354 

200,000 tpy ≤

throughput < 

750,000 tpy 

2 557,618 384 

(Control) 

 573 

(60% Control) 

159 

(No Control) 

1,116 

throughput > 

750,000 tpy 

0 0 0 

(Control) 

0 

(80% Control) 

0 

(No Control) 

0 

Total 16 1,058,183 1,630 1,615 301 3,546

The total estimated composting emission reductions are the following: 

Estimated VOC Emission Reductions = Total Current VOC Emissions (tpy) 

 -Total VOC Emissions After Reduction (tpy) 

 = 5,064 tpy – 3,546 tpy 

 = 1,518 tpy

District staff estimates that current VOC emissions from current composting facilities are 

about 5,064 tons per year. After full rule implementation, the current facilities will emit 

about 3,546 tons per year of VOCs for an estimated VOC emission reduction of about 

1,518 tons per year or 30%. 
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Appendix B: Emission Reductions Analysis August 18, 2011 

B - 12 Final Staff Report with Appendices 

For Revised Proposed New Rule 4566

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