SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT 

FINAL STAFF REPORT 

PROPOSED AMENDED RULE 1133.1 – CHIPPING AND GRINDING 

ACTIVITIES 

PROPOSED RULE 1133.3 – EMISSION REDUCTIONS FROM GREENWASTE 

COMPOSTING OPERATIONS 

July 2011 

Planning, Rule Development, and Area Sources 

Deputy Executive Officer 

Planning, Rule Development and Area Sources 

Elaine Chang, DrPH 

Assistant Deputy Executive Officer 

Planning, Rule Development and Area Sources 

Laki Tisopulos, Ph.D., P.E. 

Assistant Deputy Executive Officer 

Engineering and Compliance 

Jill Whynot 

Author: Jong Hoon Lee, Ph.D. – Air Quality Specialist 

 

Technical Assistance: 

Jay Chen – Senior Air Quality Engineering Manager 

David Jones – Air Quality Analysis & Compliance Supervisor 

Charles Tupac – Air Quality Analysis & Compliance Supervisor 

Mike Garibay – Senior Air Quality Engineer 

Eric Padilla – Air Quality Engineer 

Reviewed by: 

Tracy A. Goss, P.E. – Program Supervisor 

Barbara Baird – District Counsel 

Veera Tyagi – Senior Deputy District Counsel 
SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT 

GOVERNING BOARD 

Chairman: DR. WILLIAM A. BURKE

Speaker of the Assembly Appointee 

Vice Chairman: DENNIS YATES 

 Mayor, Chino 

Cities of San Bernardino 

MEMBERS: 

MICHAEL D. ANTONOVICH 

Supervisor, Fifth District 

County of Los Angeles 

JOHN J. BENOIT 

Supervisor, Fourth District 

County of Riverside 

MICHAEL A. CACCIOTTI 

Councilmember, South Pasadena 

Cities of Los Angeles County/Eastern Region 

JANE W. CARNEY 

Senate Rules Appointee 

JOSIE GONZALES 

Supervisor, Fifth District 

County of San Bernardino 

RONALD O. LOVERIDGE 

Mayor, Riverside 

Cities of Riverside County 

JOSEPH K. LYOU, Ph. D. 

Governor’s Appointee 

JUDITH MITCHELL 

Councilmember, Rolling Hills Estates 

Cities of Los Angeles County/Western Region 

SHAWN NELSON 

Supervisor, Fourth District 

County of Orange 

JAN PERRY 

Councilmember, Ninth District 

City of Los Angeles 

MIGUEL A. PULIDO 

Mayor, Santa Ana 

Cities of Orange County 

EXECUTIVE OFFICER:

BARRY R. WALLERSTEIN, D.Env.
TABLE OF CONTENTS 

Executive Summary ...........................................................................................................1 

Background ........................................................................................................................3 

Public Process .....................................................................................................................7 

Legal Authority ..................................................................................................................8 

Control Methods ................................................................................................................8 

Summary of Proposed Rules ...........................................................................................12 

Emissions Inventory and Reductions .............................................................................21 

Cost Effectiveness .............................................................................................................24 

Incremental Cost Effectiveness .......................................................................................24 

Environmental Assessment .............................................................................................25 

Socioeconomic Assessment ..............................................................................................26 

Comparative Analysis ......................................................................................................26 

Conclusions .......................................................................................................................36 

References .........................................................................................................................37 

Appendix I – Composting Process 

Appendix II – Emission Control Technology 

Appendix III – Emission Reductions and Cost Effectiveness 

Appendix IV – Public Comments and Responses 
List of Tables 

Table 1. Estimated Number of Chipping and Grinding Facilities .....................................22 

Table 2. Number and Throughput of Affected Greenwaste Composting Facilities ..........23 

Table 3. Emissions Inventory and Emission Reductions for Existing Greenwaste 

Composting Operations ......................................................................................24 

Table 4. Greenwaste Composting Average Cost Effectiveness .........................................24 

Table 5. Comparison of State Regulation and District Proposed Rules ............................28 

Table I-1. Commonly Used Raw Compost Materials ...................................................... I-3 

Table I-2. Troubleshooting and Management Guide for Composting 

 Conditions ....................................................................................................... I-5 

Table III-1. Emission Tests Used to Develop the Baseline Emission Factors .............. III-1 

Table III-2. Composting Emission Factors ................................................................... III-2 

Table III-3. Greenwaste Composting Baseline Emission Factors (EF) ........................ III-4 

Table III-4. Greenwaste Composting Baseline Emissions Inventory ........................... III-5 

Table III-5. Weighted Average Control Efficiency for VOC and Ammonia ............... III-6 

Table III-6. Greenwaste Composting Emission Reductions ......................................... III-8 

Table III-7. Compliance Cost Estimates and Proposed Rule Requirement ................ III-10 

Table III-8. Greenwaste Composting Average Cost Effectiveness (C-E) .................. III-10 
List of Figures 

Figure I-1. Composting Process ........................................................................................ I-1 

Figure I-2. Flow of Typical Greenwaste Composting Operation ..................................... I-1 

Figure II-1. Covered Negative-pressure ASP with Biofilter System .............................. II-1 

Figure II-2. GORE® Cover System Configuration ........................................................ II-3 

Figure II-3. Covered Positive-pressurized MOR Compost Cover .................................. II-4 

Figure III-1. VOC Emissions Profile for Greenwaste Composting .............................. III-3 

Figure III-2. Ammonia Emissions Profile for Greenwaste Composting ...................... III-4 
Preface

On June 7, 2011, the Draft Staff Report and Proposed Amended Rule (PAR) 1133.1 – 

Chipping and Grinding Activities, and Proposed Rule (PR) 1133.3 – Greenwaste 

Composting Operations were released for a 30-day public review for a July 8, 2011 

Public Hearing. This Final Staff Report contains staff’s current proposal for PAR 1133.1 

and PR 1133.3 which are scheduled for a July 8, 2011 Public Hearing. Changes and 

clarifications made to the rule since the June release of the PAR 1133.1 and PR 1133.3 

package are summarized below: 

• Clarify that the non-putrescible materials may be excluded in calculation of 

annual foodwaste throughput, provided they are quantified and records are 

maintained; 

• Add 7 days maximum to the greenwaste holding time in PAR 1133.1 (d)(2). 

Also, remove the 48-hour timeframe from PR 1133.3 (d)(1)(A); 

• Modify the time required to apply the finished compost cover from three hours to 

24 hours of initial pile formation; 

• Modify the time required to apply water from three hours to six hours before 

turning; 

• Add official federal and state holidays to be excluded from the 48-hour timeframe 

in PAR 1133.1 (d)(2); 

• Add allowance of turning a pile within 7 days of the finished compost cap to 

manage temperature of the pile in PR 1133.3 (d)(2)(D); and 

• Make other minor clarifications. 

Updates to the staff report to reflect these and other minor changes are presented in 

strike-out/underline format. 
PAR 1133.1 and PR 1133.3 Final Staff Report 

EXECUTIVE SUMMARY 

The South Coast Air Quality Management District (SCAQMD or the District) adopted a 

series of rules (Rules 1133, 1133.1 and 1133.2) in January 2003 covering chipping and 

grinding activities, and co-composting operations. Composting is a biological process in 

which organic material is decomposed by microorganisms under controlled conditions to 

produce compost that can be used to reintroduce nutrients into the soils. Compost 

production operations have several benefits in developing a sustainable environment. To 

name a few, compost use enhances overall air quality by mitigating all forms of carbon 

and nitrogen emissions, volatile organic compounds (VOCs), methane, and renewable 

carbon dioxide (CO2) versus non-renewable fossil fuel CO2, and enhances waste 

management by turning a material often put into landfills to a beneficial use to enhance 

the sustainability of major industries, including agriculture, landscape and natural lands 

restoration and management. VOCs and ammonia emissions still occur during this 

process, but can be reduced cost-effectively using simple management practices. Over 

400,000 tons of greenwaste is composted in the District each year. Approximately 2.7 

tons per day VOC and 0.4 tons per day ammonia are emitted from greenwaste 

composting in the District. If not done properly, greenwaste composting can also result 

in odor problems. Odor regulation of composting is under the authority of the Local 

Enforcement Agencies, not the District (California Health and Safety Code Section 

41705). 

Proposed Rule (PR) 1133.3 would reduce 0.9 tons per day of VOC and 0.1 tons per day 

of ammonia from greenwaste composting operations. PR 1133.3 would implement 

Control Measure (CM) MCS-04 of the 2007 Air Quality Management Plan (AQMP) and 

seeks to establish operational best management practices (BMPs) for greenwaste 

composting operations that produce active or finished compost from greenwaste-only or 

greenwaste in combination with manure or foodwaste. Amending Rule 1133.1 is 

proposed to better manage stockpile operations associated with chipping and grinding 

activities, which is to be consistent with current greenwaste material processing 

requirements established in Title 14 of the California Code of Regulations (CCR). 

Proposed Amended Rule (PAR) 1133.1 covers approximately 70 facilities and would 

establish BMPs for chipping and grinding activities to produce materials other than active 

or finished compost. No emission reductions are quantified for this rule proposal because 

the rule incorporates existing state requirements. PAR 1133.1 would also establish 

maximum holding times of greenwaste material. PAR 1133.1 would apply to chipping 

and grinding activities not only occurring at a stand-alone chipping and grinding facility, 

but also occurring at a material recovery facility (MRF), a landfill using this material for 

alternative daily cover (ADC), a transfer station, a biomass energy production facility or 

a composting facility. PAR 1133.1 would establish requirements for processing 

greenwaste for other uses than composting. Under PAR 1133.1, greenwaste would be 

required to be chipped or ground and utilized or removed from the site within 48 hours of 

receipt, or up to seven days maximum with approval from the Local Enforcement Agency 

(LEA). Chipping and grinding facilities cannot take foodwaste, unless otherwise allowed 

by the LEA. 

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PAR 1133.1 and PR 1133.3 Final Staff Report 

PR 1133.3 would affect 17 facilities and would apply to greenwaste composting 

operations involving organic waste materials, including greenwaste, woodwaste, manure 

and foodwaste. Greenwaste composting including greater than 20 percent manure is 

presently subject to Rule 1133.2 for co-composting operations. PR 1133.3 has 

requirements for the operator to process greenwaste for on-site composting as allowed by 

the LEA. Foodwaste is subject to a 48 hours processing time to initiate composting onsite, or would be required to be covered by finished compost until used. For composting 

operations of greenwaste-only or greenwaste mixed with up to 20 percent manure, by 

volume, or up to 5,000 tons per year of foodwaste throughput, operators would be 

required to cover each active phase pile with finished compost within 24 hours of initial 

pile formation, such that the top is at least six inches thick and the pile is not turned for at 

least the first seven days of the active phase of composting. Operations would be 

required to apply water to a three inch depth to the pile, prior to turning, during the first 

15 days of the active phase of composting. 

For greenwaste composting operations processing greater than 5,000 tons per year of 

foodwaste throughput, the operator would be required to install an emission control 

device for all active phase compost piles containing foodwaste content of 10 percent or 

more, by weight. An emission control device would need to be designed, operated and 

maintained with an overall system control efficiency of at least 80 percent, by weight, for 

VOC and ammonia emissions, respectively. None of the facilities are currently 

processing this amount of foodwaste. 

PAR 1133.1 also has the 48 hours or up to seven days material holding time requirement 

which is shorter than the previous holding time requirements of Rule 1133.1. The 

amended 48 hours or up to seven days maximum holding time requirement is to conform 

to that of the existing state regulation (Title 14) which is currently enforced by the 

county-level LEAs. As the holding time requirement has already been established and 

enforced by the LEA, no emission reductions are quantified relative to PAR 1133.1. 

Costs associated with the implementation of PR 1133.3 involve operation and 

maintenance (O&M) costs to apply finished compost and additional watering to the 

compost piles before turning for the first 15 days of the active phase composting. These 

costs include water irrigation costs, including purchase of potable and/or reclaimed water 

and labor, and finished compost cover costs that do not include the capital cost of the 

application equipment. Costs are proportional to the amount of greenwaste processed, 

which ranges from less than 5,000 tons to 200,000 tons per year per facility. Total annual 

O&M costs range from $700 to ~$200,000 per facility (facility annual average of 

$29,000 per year). Overall, for PR 1133.3, average cost effectiveness is estimated to be 

$1,340 per ton of VOC-only and $1,270 per ton of VOC and ammonia combined. If addon emission controls were required due to foodwaste throughput above the 

aforementioned thresholds, incremental cost effectiveness would be $6,600 per ton of 

VOC-only and $5,700 per ton of VOC and ammonia combined for a 50,000 tons per year 

operation, when compared to finished compost cover and watering application. 

Several working group and other industry stakeholder meetings have been held to discuss 

rule concepts and draft rule language. A public workshop was held in February 2011. 

SCAQMD 2 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Numerous facility meetings have also occurred, as well as many site visits and phone 

calls. As a direct result of these meetings, rule language was refined. Staff will evaluate 

other uses of greenwaste for potential future rulemaking.

BACKGROUND 

AIR QUALITY 

The SCAQMD is the regional government agency responsible for air quality in all of 

Orange County and the non-desert portions of Los Angeles, Riverside and San 

Bernardino counties. The District’s jurisdictional boundaries include all of the South 

Coast Air Basin (Basin) and portions of the Salton Sea Air Basin (SSAB). Although air 

quality in the Basin has remarkably improved in the past decades, the air still does not 

meet all federal and state air quality standards. The U.S. EPA has designated the Basin 

as “extreme” non-attainment for 8-hour ozone standard. The Basin has been designated 

as non-attainment for PM2.5. The District is required to meet the federal annual PM2.5

standard by 2015 and the federal 8-hour ozone standard by 2024, respectively. 

Organic materials comprise about 40 percent of California’s waste stream. Diverting a 

high percentage of these materials is key to the state achieving and maintaining the 

diversion goals of the California Integrated Waste Management Act (AB939, Sher, 

Chapter 1095, Statues of 1989 as amended [IWMA]). Pursuant to AB939, composting 

has been promoted statewide to achieve waste diversion goals. Composting is a good 

mitigation measure for greenhouse gas (GHG) emissions reduction, as well. Much 

smaller quantities of methane are emitted from aerobic composting than from 

uncontrolled anaerobic decomposition. Good composting practices, which balance the 

carbon-to-nitrogen (C:N) ratio and provide adequate aeration and moisture, will minimize 

VOC, ammonia and GHG emissions. 

Interest in foodwaste composting is also on the rise. Foodwaste, if not recycled via 

composting, is sent to landfills. More than six million tons of food scraps are generated 

each year in the state, which is about 15 percent of landfill material. Composting is a 

beneficial way to recycle food scraps into reusable compost and reduce emissions of 

methane, a potent GHG. Currently, the vast majority of food scraps are landfilled. 

Greenwaste composting is a source of ammonia, a PM2.5 precursor, and VOCs, an ozone 

precursor. Biogenic VOC also acts as a precursor gas to form secondary aerosols. 

Ammonia can be emitted from improperly managed composting piles and act as a 

precursor gas to form secondary aerosols. Annually, over 12 million tons of compostable 

organic materials, such as foodwaste and landscape trimmings, are sent to California 

landfills. In 2006, methane emissions from composting (primarily of greenwaste and 

food scraps from residential and commercial establishments) in the U.S. were estimated 

to be 75 gigagrams (Gg), which accounts for only 1.3 percent of 5,985 Gg of the landfill 

methane emissions1

. In the South Coast, gas recovery control systems have been 

required to be employed for decades. These systems effectively collect VOC and 

methane, as a result that landfill emissions are well controlled in the Basin. Therefore, 

diverting organic materials not only helps return valuable nutrients to the soil, improves 

SCAQMD 3 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

plant productivity, and helps reduce water usage, erosion, and chemical use, but it also 

can reduce GHG emissions from landfills not equipped with gas control systems2

. 

Following is a brief description of the health and environmental concerns with air 

contaminants emitted from organic treatments, including greenwaste composting, that 

contribute to the formation of PM2.5 and ozone, and climate change. The management 

practices proposed in PAR 1133.1 and PR 1133.3 will reduce ammonia and VOC, 

precursors to PM2.5 and ozone, as well as minimize PM2.5 emissions. 

Particulate Matter (PM2.5) 

Most PM2.5 in the Basin’s air is believed to be in the form of secondary aerosols, such as 

ammonium sulfate and ammonium nitrate that are formed by reactions of ammonia with 

acidic gases, or such as secondary organic aerosols formed from biogenic VOC. PM2.5 is 

associated with adverse health effects. A great fraction of particles in this size range can 

penetrate and deposit deep in the lungs, damaging the airways of the lower respiratory 

tract. It should be noted that PM emissions from material movement is, in general, 

controlled relative to compliance with Rule 403 – Fugitive Dust. 

Ozone 

VOC is produced from greenwaste composting as a by-product of biological degradation 

of organic materials. Not only is VOC produced during aerobic composting of organic 

materials, but VOC is also produced in even greater quantity in anaerobic decomposition. 

VOC contributes to the formation of ozone and organic aerosols in the atmosphere, 

contributing to higher PM2.5 and lower visibility levels. Ozone is formed in the 

atmosphere through a photochemical reaction of VOC and nitrogen oxides (NOx) by 

sunlight. 

Ozone is a highly reactive compound and a strong oxidizing agent. When ozone comes 

into contact with the respiratory tract, it can react with tissues and cause damage in the 

airways. Ozone is a deep lung irritant, causing the lung passages to become inflamed and 

swollen. Exposure to ozone produces alterations in respiration, the most characteristic of 

which is shallow, rapid breathing and a decrease in pulmonary performance. 

Greenhouse Gases 

Greenhouse gases, such as CO2, methane (CH4), and nitrous oxide (N2O), are emitted to 

the atmosphere through natural processes and human activities. These GHGs are 

associated with composting. All organic materials contain carbon. When organic 

materials are decomposed naturally under aerobic conditions, CO2 is emitted as part of 

the natural short-term carbon cycle. When organic materials are placed in an anaerobic 

environment, anaerobic decomposition will emit methane and some VOCs. 

Methane is emitted from uncontrolled anaerobic decomposition of waste. Although 

landfill methane emissions are well controlled in the SCAB, landfills are the largest 

human-related source of methane in the U.S., accounting for 34 percent of all methane 

emissions. Methane is generated in landfills and open dumps as waste decomposes under 

anaerobic (without oxygen) conditions. The amount of methane created depends on the 

SCAQMD 4 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

quantity and moisture content of the waste and the design and management practices at 

the site. Even though methane is formed in anaerobic sections at the bottom of compost 

piles, it is oxidized to a large extent as it reaches more aerobic sections of the compost 

piles. Anaerobic sections are created in composting piles when there is excessive 

moisture and inadequate aeration of the piles. The estimated methane released into the 

atmosphere ranges from less than one percent to a few percent of the initial carbon 

content in the compost material1

. The District has rules to capture methane and VOC 

emitted from landfills. Nitrogen-high organic materials, such as manure, grass clippings, 

and food scraps, under wet and oxygen-limited conditions, can also produce N2O during 

decomposition. The range of the estimated emissions varies from less than 0.5 percent to 

five percent of the initial nitrogen content of the material. 

Regulatory Background 

Following is a summary of the regulatory programs that are applicable or pertinent to the 

greenwaste composting operations industry. 

Federal Programs 

Resource Conservation and Recovery Act

In 1976, Congress enacted the Resource Conservation and Recovery Act (RCRA), an 

amendment to the 1965 Solid Waste Disposal Act. RCRA calls for conservation of 

energy and natural resources, waste reduction, and environmentally sound waste 

management practices. In addition, RCRA encourages states to develop plans for nonhazardous industrial solid waste and municipal solid waste (MSW) management, sets 

criteria for MSW landfills, as well as for other solid waste disposal facilities, and 

prohibits the open dumping of solid waste. Congress delegated authority to U.S. EPA to 

develop scientific regulations to implement the requirements of RCRA. Solid waste 

regulations have been promulgated in the Code of Federal Regulations under Title 40, 

Chapter I, Subchapter I, Parts 240-282 (40 CFR Parts 240-282). 

Sewage Sludge Disposal Standards

U.S. EPA promulgated standards for the use or disposal of sewage sludge in Title 40, 

Chapter I, Subchapter O, Part 503 of the Code of Federal Regulations (40 CFR Part 503). 

40 CFR Part 503 contains requirements for the control of pathogens, vectors, and heavy 

metal for sludge composting operations. To qualify as Class A compost, Appendix B to 

Part 503 – Pathogen Treatment Process, generally requires processes to further reduce 

pathogens (PFRP). PFRP requires that open windrow composting maintain the 

temperature of the compost at 131 degrees Fahrenheit or higher for 15 days or longer, and 

during this time there must be a minimum of five turnings of the windrows. For in-vessel 

or aerated static pile (ASP) composting, the RFRP requires the active pile temperature be 

at least 131 degrees Fahrenheit or higher for three days. This process assures that 

virtually all human pests and pathogens are destroyed. Since food residuals contain 

human pathogens, fungi and bacteria, this PFRP should be met when foodwaste is being 

mixed with greenwaste for composting. 

State Programs 

SCAQMD 5 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

California State Legislature: California Integrated Waste Management Act

Recognizing landfill limitations (i.e., capacity and siting) and the need for integrated 

waste management practices, in 1989, the California state legislature passed Assembly 

Bill (AB) 939 – California Integrated Waste Management Act into law, which was 

incorporated into the California Public Resources Code, Division 30. Cities and counties 

were mandated to achieve a total waste diversion of 25 percent by 1995 and to meet a 

total waste diversion of 50 percent every year. 

California Department of Resources Recycling and Recovery (CalRecycle)

In April 2003, the California Integrated Waste Management Board (CIWMB) 

promulgated a set of regulations governing composting operations and facilities. The 

CIWMB currently regulates approximately 115 composting facilities operating in 

California in accordance with the California Code of Regulations, Title 14, Division 7, 

Chapter 3.1 – Composting Operations Regulatory Requirements (Chapter 3.1). Chapter 

3.1 has requirements for handling compostable materials including, but not limited to, 

material residence time at facilities and temperature requirement to prevent inadvertent 

decomposition. This Chapter also has a pathogen reduction requirement that requires 

open windrow composting maintain the temperature of the pile at 131 degrees Fahrenheit 

or higher for at least 15 days or longer during which windrows must be turned at a 

minimum of five times. Depending on the type of composting materials and the 

throughput, affected facilities are required to obtain a Notification or a Full Solid Waste 

Facilities Permit (Full Permit) that are issued by LEAs, such as the environmental health 

departments. There are also requirements for green material composting operations and 

facilities, as well as an Odor Impact Minimization Plan (OIMP). [Note: the CIWMB was 

formerly part of Cal-EPA, is now part of the Resources Agency, but many of the actions 

referenced and discussed herein occurred before that time.] 

2007 Strategic Directive 6.1

In 2007, the CIWMB adopted Strategic Directive 6.1, which in addition to the diversion 

required under AB 939, seeks an additional 50 percent of organics diverted from landfills 

by 2020, in accordance with the waste management hierarchy and in support of the 

California Global Warming Solutions Act of 2006. The CIWMB has estimated that 

meeting Strategic Directive 6.1 may require 50 to 100 new organics processing facilities

(or equivalent expansion of existing facilities) that produce compost, biofuels, and/or 

bioenergy; increased development of product standards and increased procurement by 

private and public entities; and resolution of cross-agency regulatory issues. 

Regional Water Quality Control Board

The Regional Water Quality Control Board (RWQCB) issues and enforces National 

Pollutant Discharge Elimination System (NPDES) permits. In addition, the RWQCB 

focuses on wastewater generation, water demand, the capacity of existing or planned 

stormwater drainage systems and potential new sources of polluted run-off, and potential 

depletion of groundwater supplies or interference with groundwater recharge. In the case 

of composting facilities, the RWQCB has required various composting sites to be graded, 

paved, and surrounded by berms and other drainage-related protections to prevent run-off 

and the leaching of chipped and ground materials into the groundwater. 

SCAQMD 6 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Local Programs 

There are several local requirements that may apply to greenwaste composting 

operations. Specifically, these requirements focus on air, land use and solid waste issues. 

The following is a summary of these requirements. 

SCAQMD Rule Requirements

Currently, operators of chipping/grinding operations at greenwaste composting facilities 

are required to comply with SCAQMD Rules 402 – Nuisance, 403 – Fugitive Dust, and 

203 – Permit to Operate for equipment that require permits. In addition, greenwaste 

composting operations are required to comply with District Rules 1133 – General 

Administration, 1133.1 – Chipping and Grinding, and 1133.2 – Emission Reductions 

from Co-Composting Operations involving more than 20 percent manure. However, 

none of these rules establish specific control requirements to reduce VOC and ammonia 

emission from greenwaste-only composting operations. 

Local Enforcement Agency Requirements

There are several different local (i.e., city or county) enforcement agencies or LEAs that 

act as either the permitting or enforcement division of the CIWMB, depending on the 

throughput and type of compostable materials. For example, the local department of 

health services, on behalf of the CIWMB, issues Registration, Standardized, and Full 

Permits depending on the size of throughput and enforces the requirements in these 

permits. For either type of permit scenario, the LEAs are responsible for handling and 

investigating complaints from composting and chipping/grinding operations. Pursuant to 

Health and Safety Code Section 41705, composting operations are exempt from 

SCAQMD odor regulations; SCAQMD must refer odor complaints to the LEA. 

Local Governments

Local government zoning ordinances determine where composting activities can occur. 

In addition, local government grant conditional use permits if the jurisdiction has 

determined that special conditions and approvals are necessary. 

PUBLIC PROCESS 

Staff invited environmental and community group representatives, industry 

representatives, government staff, consultants and individuals from affected industry to 

participate in a working group. The first working group meeting was held on June 8, 

2010 and a subsequent follow-up conference call was held on June 18, 2010 to 

accommodate people who were not able to participate in the first working group meeting 

due to technical difficulties with the conference call. A second working group meeting 

was held on August 27, 2010 with revised concepts and preliminary draft rule language. 

Three written comment letters were received from participants for initial concepts 

discussed at the first working group meeting and seven additional comment letters were 

received regarding the revised concepts and preliminary draft rule language. Staff has 

made many site visits and has met with industry representatives on several occasions to 

address key issues relative to proposed rule requirements. A public workshop was held 

on February 9, 2011 and 15 written comments were received. The rule proposal was 

SCAQMD 7 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

revised based on those comments and the third working group meeting was held on May 

10, 2011 with the revised rule proposal. Nine additional written comments were received 

as a result of the third working group meeting. Staff further revised the rule language and 

held another working group meeting on June 15, 2011. The revised rule proposal is 

based on all the verbal and written comments that were received since the Public 

Workshop and are responded to in Appendix IV. A Public Hearing is scheduled for July 

8, 2011. 

LEGAL AUTHORITY 

The SCAQMD obtains authority to adopt, amend, or repeal rules and regulations which 

control air pollution from Health and Safety Code §§ 39002, 40000, 40001, and 40440. 

CONTROL METHODS 

According to the District’s greenwaste composting industry survey conducted in 2007, 

the predominant method of greenwaste composting is windrow composting. Composting 

is a biological process where organic material is decomposed by microorganisms under 

controlled conditions in the presence of oxygen to produce a compost material that can be 

used to reintroduce nutrients into the soils. Two composting methods are commonly 

conducted: static pile composting and turned windrow composting. Static pile 

composting is characterized by infrequent turning, which is similar to backyard 

composting on a larger scale. The material is placed into piles where it decomposes over 

an extended period of time with no or little mixing during the composting process. 

Therefore, it is crucial to construct the pile to the appropriate size, with the material being 

thoroughly blended and having a moisture content and porosity to allow adequate 

aeration through the composting process. In turned windrow composting, materials are 

moved with a front-end loader into long piles called windrows. Aeration is achieved both 

by natural advection and mechanically turning the piles with a front-end loader or a 

windrow turner, such as a Scarabs machine. Temperature, moisture content and oxygen 

concentration are maintained to optimize and hasten decomposition. After two to four 

months of composting in the piles or windrows, the material becomes finished compost. 

PR 1133.3 does not require a specific type of composting, and thus any type of 

composting technique can be used for the process. PR 1133.3 requires two different 

levels of emission control methods to reduce gaseous emissions from greenwaste 

composting operations. The type of an emission control method required is determined 

based on the annual foodwaste throughput on a facility-wide basis. In order to comply 

with the requirements of PR 1133.3, new and existing greenwaste composting operations 

processing greenwaste by itself or operations with up to 20 percent manure, by volume, 

or with up to 5,000 tons per year of foodwaste throughput (source-separated or mixed) 

would require a combination of finished compost cover and additional water irrigation. 

The operator would need to apply finished compost cover to the top of active greenwaste 

composting piles at least for the first seven days of the active phase of composting, and 

then apply water to the pile for the remaining days of the first 15 days of the active phase 

period of composting. The finished compost cover and water application is considered as 

a best management practice (BMP), not an emission control technology per se. If more 

SCAQMD 8 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

than 5,000 tons per year of foodwaste throughput is composted, an emission control 

device would be required for any active phase composting pile containing a foodwaste 

content of 10 percent or more, by weight. If existing greenwaste composting facilities 

determine after rule adoption to process greater than 5,000 tons per year of foodwaste 

throughput and a foodwaste content of 10 percent or more, by weight, an emission 

control technology achieving an 80 percent overall control efficiency would also be 

required. 

Finished Compost Cover 

PR 1133.3 would require applying either screened or unscreened, finished compost 

and/or compost overs to the top of greenwaste composting piles at least during the first 

seven days of the active phase of composting so that the peak is six inches thick. Tests 

have shown that the emissions primarily escape from the top one third of the pile. The 

proposal requires the compost cover such that the top is covered to a depth of six inches, 

and tapers off as it goes down the pilesides. Thus, the application is adequate to cover 

the top half of the pile where most emissions emanate. Finished compost is required to 

be applied to the active phase piles within 24 hours of initial pile construction and sit for 

a minimum of seven days with the piles unturned. This so-called “pseudo-biofilter” 

approach is effective in reducing VOC emissions from composting piles. According to 

the recent greenwaste mitigation measure study3

, the application of six inches finished 

compost to the surface of a greenwaste windrow resulted in a 53 percent reduction in 

VOC emissions for the 22-day active phase period compared to the regular greenwaste 

windrow without finished compost on it. In the Modesto Emissions Study4, a 75 percent 

reduction in VOC emissions was achieved with a six inches layer of finished compost 

cover for the first two weeks of the active composting phase. Another recent emissions 

research5 using a compost cap made out of oversized materials screened from finished 

compost, known as “compost overs”, showed that biofilter cap made out of overs reduced 

average measured ozone formation by 27 percent in five days old piles and by 36 percent 

in 21 days old piles. Compost overs have been through the pathogen reduction process 

outlined in Title 14, Section 17868.3 of the California Code of Regulations. Literature6

shows that finished compost has also been used as a means to oxidize methane from 

landfills before it is released to the atmosphere and has been used as biofilter media. 

The emissions during the active phase period of composting surpass the emissions during 

the curing phase and account for the vast majority of the total emissions. Emissions for 

the first 15 days of the active phase period account for a majority (87 percent) of the total 

integrated VOC emissions. In addition, more VOC emissions occur during the first half 

of the 15 days period than during the last half period. 

The use of screened or unscreened finished compost and/or compost overs is considered a 

practical application since these materials are readily available at composting facilities. 

Compost overs do not decompose in a typical composting cycle anyway and are recycled 

back into the process by using it as a cover material. If finished compost is utilized as a 

cover material, it is initially recycled back into the process by using it to cover windrows 

and it is also not consumed in the process. It cycles back to finished compost at the end 

of the composting process. PR 1133.3 requires only one time application of finished 

SCAQMD 9 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

compost cover and/or compost overs and thus there would be one time (temporary) loss 

of product sale. Use of finished compost as a pseudo-biofilter cover is a cost-effective 

emission mitigation measure to reduce VOC emissions from composting piles. Costs to 

apply finished compost cover mainly involve application time and a front-end loader 

operation cost. 

Water Irrigation 

PR 1133.3 would also require applying water to the surface of the compost piles so that 

three inches in depth of the pile is wet. According to the mitigation measure study3

, 

water irrigation was tested on an active phase composting windrow and showed 24 

percent reductions in VOC emissions during the 22 days active phase composting period. 

Since most compost piles are already watered for the composting process, water 

irrigation would not be difficult for most of the composting facility operators. Excess 

moisture is also evaporated while turning the piles and will not lead to oversaturation and 

leaching issues. It should be noted that water is only required in amounts necessary to 

make the top three inches wet and does not require water application indiscriminately. 

The costs of water irrigation involve the use of potable and/or reclaimed, well, or canal 

water. 

Emission Control Device 

An emission control device would be required only for operations having greater than 

5,000 tons per year of foodwaste throughput, either on a source-separated or mixed 

foodwaste basis, and a foodwaste content of 10 percent or more, by weight. PR 1133.3 

does not propose any specific type of emission control technology for greenwaste 

composting operations. However, an emission control device should be designed, 

constructed, maintained, and operated to achieve overall system control efficiency of at 

least 80 percent, by weight, for VOC and ammonia emissions, respectively. Aerated 

static pile (ASP) venting to biofilter is one example of an emission control device. The 

material is placed on top of perforated pipes that are connected to blowers that either 

push or pull air through the piles. ASP can be operated either under negative pressure or 

positive pressure. Negative-pressure ASP pulls air through the pile and vents the exhaust 

to an emission control device, such as a biofilter, to remove air pollution gas emissions 

pulled from the compost pile before they are released to the atmosphere. Wood chips 

and compost can be used as biofilter media. Finished compost can be layered on the 

surface of the negative ASP to increase capture efficiency of gas emissions from the pile. 

Biofiltration is a well-established emission control technology. In the United States, 

biofilters have been mainly utilized for the treatment of odors and VOC emissions in 

wastewater treatment plants. In the Basin since District Rule 1133.2 was adopted, 

biofiltration technology has been an emission control technology for co-composting VOC 

and ammonia emissions. Based on the information collected on existing biofilter 

composting applications, overall control efficiencies of about 80 to 90 percent for VOC 

and 70 to over 90 percent for ammonia have been achieved7

. Due to technology 

advancement, a well-designed, well-operated, and well-maintained biofilter will be 

capable of achieving 80 percent control efficiency for both VOC and ammonia. Biofilter 

manufacturers also emphasize that regular inspection and maintenance of the biofilter are 

SCAQMD 10 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

key elements to achieve such control level. Based on source tests data from existing cocomposting operations (Inland Empire Regional Composting Facilities and City of Los 

Angeles Sanitation Bureau), properly designed and maintained biofilters have 

demonstrated over 90 percent destruction efficiencies for both VOC and ammonia 

emissions. However, because of concerns over the continuous effectiveness of biofilters 

in reducing emissions beyond 80 percent, a minimum of 80 percent control efficiency 

would be required under the PR 1133.3. 

Negative-pressure ASP is operated intermittently, typically with a blower turned on for 

one third of the operational time. If it is operated on a continuous basis, it will lose a 

significant portion of moisture content in the pile because moisture will be drawn 

together with the exhaust gas emissions, leading to microorganisms entering a dormant 

stage. 

There are different ASP technologies utilizing a fabric cover or a tarp. These 

technologies are called covered ASP systems. A covered ASP system can be aerated 

positively or negatively, and uses an engineered fabric cover, instead of finished 

compost, as a cover material. One such system is covered negative-pressure ASP with 

biofilter8

. The compostable material is placed on a ventilation pipe and covered with a 

waterproof cover tarp, following the insertion of monitoring probes. The pipe is 

connected to a blower that produces negative air pressure, pulling air into the pile from 

the outside through small holes in the tarp. As air is being drawn through the piles, it is 

sent to a biofilter composed of moist wood chips and compost. Probes are linked to a 

computer to monitor temperature. 

The other type of the covered ASP systems is covered positive-pressure ASP using triple 

layer membrane compost covers9, 10. This type of technology pushes air into the pile, and 

does not need a biofilter. The membrane covers selectively influence the process. They 

protect the composting material from the penetration of rainwater and yet allow carbon 

dioxide produced during the composting process to escape. The compost cover keeps 

heat, odors, microorganisms, and some moisture contained, while releasing oxygen and 

some moisture. Covered piles are controlled with a blower fan, connected to either onfloor aeration pipes or in-floor aeration ducts, and controlled by means of either 

temperature and oxygen9

 or temperature only10. Further description of these covered 

forced ASP systems is given in Appendix II. These covered forced ASP systems would 

cost from two million dollars to five million dollars, depending on vendors, for an 

operation with 100,000 tons throughput per year. 

Another possible emission control technology is a positive-pressure ASP with finished 

compost as a cover material. Although staff expects that such covered ASP systems will 

meet PR 1133.3 requirements, their overall control efficiencies will have to be 

demonstrated using approved source test methods and protocols. Currently, there are 

only a few source tests that were conducted locally using the District Test Methods 

protocol. 

SCAQMD 11 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

SUMMARY OF PROPOSED RULES 

This section summarizes the requirements of the proposed and amended rules in the order 

of the major rule subdivisions: Purpose and Applicability, Requirements, Test Methods 

and Protocol, Recordkeeping, and Exemptions. Each section lists major proposed 

requirement elements followed by detailed descriptions. 

Summary of Proposed Amended Rule 1133.1 – Chipping and Grinding 

Activities 

Purpose and Applicability 

The purpose of PAR 1133.1 is to prevent inadvertent decomposition occurring during 

chipping and grinding activities, including stockpile operations. This proposed amended 

rule applies to the operators of chipping and grinding activities, including stockpile 

operations, to produce materials other than active or finished compost, unless otherwise 

exempted. 

Greenwaste materials must first be chipped or ground before being further processed for 

composting, mulching, static pile for land application, ADC at landfills, or biofuels at 

biomass facilities. Air emissions may occur even at a pre-chipping and grinding stage. 

However, once greenwaste materials are chipped or ground, air emissions begin to occur 

immediately and spike within three to seven days of being chipped or ground. Tests have 

shown that extended stockpiling operations can cause extensive emissions of VOC and 

other trace air pollution gases (e.g., ammonia) to the atmosphere. In addition, chipping 

and grinding activities subject to Rule 1133.1 are also subject to the California Code of 

Regulations (CCR) Title 14 relative to compostable greenwaste material processing. 

Therefore, based on the emission and Title 14, Rule 1133.1 is proposed for amendment to 

tighten requirements on stockpile operations and harmonize the rule with Title 14. It 

should also be noted that the amendments add applicability of the rule to the operators of 

chipping and grinding activities, including stockpile operations, to produce materials 

other than active or finished compost, and are regulated under Title 14. Therefore, this 

amended rule would apply to the operators of chipping and grinding activities occurring 

not only at a stand-alone chipping and grinding facility, but also at multi-operation 

facilities that handle multiple incoming material streams with separate operating areas for 

“chip and ship” operations (such as chipping to produce mulch, biofuel, ADC or 

woodchips) within the same facility. Chipping and grinding activities to produce 

compost feedstock will be separately subject to the applicable PR 1133.3 and Title 14 

requirements. It should further be noted that as these facilities are already subject to Title 

14, amending Rule 1133.1 to strengthen the holding requirements does not cause any 

additional impact to the affected facilities. 

Requirements 

Foodwaste Management

Rule 1133.1 has been amended to state foodwaste cannot be accepted at chipping and 

grinding facilities, unless otherwise allowed by the LEA to handle foodwaste. 

SCAQMD 12 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Stockpile Operations

Once greenwaste is received at the chipping and grinding facility, the operator shall 

chip or grind and utilize on-site or remove curbside, non-curbside or mixed 

greenwaste from the site within 48 hours of receipt, excluding observance of official 

federal and state holidays, or up to seven days maximum, with approval from the 

LEA. This requirement harmonizes with Title 14, Division 7, Chapter 3.1, Section 

17852 (a)(10)(A)(2) of the CCR. Chipped or ground materials shall not be 

stockpiled, but be “utilized” for other purposes, including, but not limited to, daily 

landfill cover, land application, mulch and erosion control, or be removed from the 

site, such as being sent to a landfill for ADC use or to biomass power generation 

facility for biofuel consumption, within the applicable allotment of time. 

Recordkeeping

All the operational records, as applicable, are required to be maintained for the prior 

five years of operation, with the most recent two years retained at the facility, which 

shall be immediately available upon request by the Executive Officer. The remaining 

three years of records shall be made available within one week of request. 

Exemptions

Existing exemptions still apply to material derived and utilized on site, provided less 

than 1,000 cubic yards of materials per year are either sold or given away. Portable 

chipping and grinding, agricultural chipping and grinding, landclearing chipping and 

grinding, woodwaste chipping and grinding, and palm chipping and grinding 

activities continue to be exempt from the provisions of the rule. In this amendment, 

the operator of a landfill or biomass power generation facility would be exempt from 

the requirements of maintaining operation-specific records on-site, provided that the 

operator does not perform chipping and grinding of greenwaste on-site. 

A biomass power generation facility or a facility processing material as a biomass 

fuel for a biomass power generation facility would also be exempt from the 48 hours 

or up to seven days maximum holding time requirement, provided that the material 

temperature is maintained at below 122 degrees Fahrenheit or the moisture content is 

less than 30% and records of the temperature or moisture measurements are 

maintained on-site. With this exemption, the definition of woodwaste has been 

modified such that the woody materials of screened or unscreened greenwaste, 

exceeding 2 inches in any dimension, such as tree trimmings, branches, tree trunks, 

stumps, and limbs, would be considered woodwaste. Rule elements pertaining to 

moisture content of chipped and ground curbside greenwaste remain unchanged. 

SCAQMD 13 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Summary of Proposed Rule 1133.3 – Emission Reductions from 

Greenwaste Composting Operations 

Purpose and Applicability 

The purpose of PR 1133.3 is to reduce fugitive emissions of VOC and ammonia 

occurring during greenwaste composting operations. This proposed rule would apply to 

all new and existing greenwaste composting operations that produce active or finished 

compost from greenwaste by itself or greenwaste in combination with manure or 

foodwaste. If greenwaste material is chipped or ground to produce feedstock for 

composting, the chipping and grinding activities and associated material holding would 

be subject to the PR 1133.3 requirements. 

Certain exemptions may apply. Active compost means material that is in the process of 

being rapidly decomposed and is biologically unstable. Active compost is generating 

temperatures of at least 122 degrees Fahrenheit during decomposition. Pathogen-reduced 

mulch is included in active compost. Finished compost means a humus-like material 

and/or compost overs that result from the controlled biological decomposition of organic 

waste materials and is biologically stable. Both the active and curing phases of the 

greenwaste composting are required to achieve this finished compost product. Compost 

overs are defined as the oversized woody materials that do not decompose in a typical 

composting cycle and are screened out of finished product at the end of composting. 

Compost overs have been through the pathogen reduction process outlined in the CCR, 

Title 14, Section 17868.3. 

New greenwaste composting operations are defined as greenwaste composting operations 

that have not started operations as of rule adoption. Existing greenwaste composting 

operations are defined as all greenwaste composting operations that have begun 

operations on or before rule adoption. 

Requirements 

The proposed rule would focus on stockpile operations and composting operations of 

greenwaste and/or foodwaste at all new and existing composting facilities that are either 

registered for a Notification tier or permitted by the LEA to conduct composting 

operations. The level of requirements would depend on the annual foodwaste throughput 

on a facility-wide basis. 

For all greenwaste composting operations: 

Effective upon rule adoption, the operator of greenwaste composting operation is 

required to chip or grind, as necessary, and use greenwaste for on-site composting 

within 48 hours of receipt as allowed by the LEA. This requirement is consistent 

with the requirement of the state regulation pursuant to the CCR, Title 14, Division 7, 

Chapter 3.1, Section 17852 (a)(10)(A)(2). In addition, foodwaste should be used for 

on-site composting within 48 hours of receipt or covered with screened or unscreened 

finished compost until used. 

SCAQMD 14 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

For operations processing greenwaste only, greenwaste with up to 20 percent 

manure, by volume, or up to 5,000 tons per year of foodwaste throughput: 

Allowance of Manure or Foodwaste

For the purpose of this proposed rule, up to 20 percent manure, by volume, integrated 

into greenwaste is considered greenwaste composting. This percent limit has been 

already established in District Rule 1133.2 – Emission Reductions from CoComposting Operations (adopted in January 2003), because it was difficult for 

agricultural farm composters to completely separate horse manure from horse 

bedding materials for composting. However, other kinds of animal manure would 

also be allowed up to 20 percent, by pile volume, under PR 1133.3. More than 20 

percent manure, by volume, would not be considered as greenwaste composting, but 

would be subject to Rule 1133.2 for co-composting operations. Up to 5,000 tons per 

year of foodwaste throughput can be composted without the need to install an 

emission control device. This proposed foodwaste throughput is on a facility-wide 

basis, and either source-separated or mixed foodwaste is counted. Mixed foodwaste 

contains compostable material (e.g., compostable plastic bags, food-soiled packaging, 

papers, or other biodegradable material) and/or non-compostable solid waste (e.g., 

glass, cans, napkins, plastics including bags, containers or styrofoam). The annual 

throughput calculation may exclude any non-putrescible materials, including, but not 

limited to, paper, woody, other low-water, high cellulose materials, and noncompostable contaminants and greenwaste that are separated either before or after 

composting and shipped off-site for disposal, provided they are quantified and 

appropriate records are maintained. 

Foodwaste means any pre- and post-consumer food residuals collected from the food 

service industry, grocery stores, or residential food scrap collection. There is no 

restriction on the recipes of foodwaste-to-greenwaste ratio. 

Mitigation Measures: Finished Compost Cover and Watering

Every active phase pile is required to be covered with finished compost within 24 

hours of initial pile formation such that the top is six inches thick and the pile is not 

turned for the first seven days of the active phase period of composting. Tests have 

shown the emissions primarily escape from the top one third of the pile. Having a six 

inch compost cover at the top ensures that the pile is adequately covered and tapers as 

it goes down the pilesides. Thus, the application is adequate to cover the top half of 

the pile where most emissions emanate. 

Tests have shown that a vast majority of VOC emissions are extensively produced 

during the first 15 day active phase period of composting. In particular, the emissions 

tend to spike within the first three to seven days of the active phase of composting 

and then diminish with time. According to a mitigation measure study3

, about 53 

percent of VOC emission reductions were achieved with six inches of finished 

compost layer applied upon initial pile formation and each subsequent turning during 

the first 22 day active phase composting. VOC is a biodegradable chemical and is 

adsorbed on the finished compost layer, and is further broken down by the microbes 

SCAQMD 15 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

living on the surface of the finished compost. To minimize facility impacts, the 

compost cover is only proposed for initial pile formation and the pile is not to be 

turned for seven days unless needed to manage temperature or for pathogen 

reduction. 

Additional watering is also proposed as a subsequent mitigation measure following 

finished compost cover to reduce VOC and ammonia emissions from turned compost 

piles. For the first 15 days after initial pile formation for the active phase period of 

composting, water is to be applied as necessary to the surface area of all active phase 

piles within six hours before subsequent turning such that the pile is wet to a depth of 

three inches. When applying water to the pile, the top one half of the pile needs to be 

wet down to a three inch depth. Alternatively, the operator may apply water during 

turning using a windrow turner equipped with water spraying technology during the 

entire windrow turning process. 

According to the composting mitigation measure study3

, the surface irrigation could 

help reduce VOC emissions from greenwaste compost piles by 24 percent. VOC 

emitted from composting of organic wastes consists of biodegradable and watersoluble light alcohols to some extent. VOC entrapped inside the pile as a result of 

biological decomposition of organic material is emitted to the air when the pile is 

turned. As water is applied to the surface area, the water layer of the pile absorbs 

water-soluble VOC and emission reductions occur. Because only the top three inches 

of the pile irrigated becomes wet, there would be no water run-off problems 

associated with additional watering. Staff also expects that excess moisture is 

evaporated while turning the piles and will not lead to oversaturation and leaching 

issues, as well as anaerobic condition issues. 

If a rain event occurs prior to watering the pile within six hours before turning and the 

pile is wet to a depth of three inches, the operator may turn the pile without adding 

additional water. It is recommended that the operator conduct a ball test using hand 

pressure. At least three inches depth from the peak of a pile, if the compostable 

material contains enough moisture to form a ball when compressed by hand, but may 

break when tapped, within six hours before turning, no additional watering would be 

required. If the ball crumbles upon release of the hand pressure test, additional water 

would be required to apply to the pile until requirements are met. This may also 

apply to a normal operating condition. If the pile is sufficiently wet down to a three 

inch depth within six hours before turning during non-rain, normal operations, 

additional watering may not be required. If the pile needs to be turned within the first 

seven days for maintaining temperature at or above 131 degrees Fahrenheit for 

pathogen reduction pursuant to Title 14, Division 7, Chapter 3.1, Section 17868.3 of 

the CCR, the operator does not need to re-apply the finished compost cover and 

should apply additional water to the pile as described in this section. 

An alternate mitigation measure may be implemented by the operator, provided that 

the measure will be based on a test protocol approved by the Executive Officer, 

California Air Resources Board, and the United States Environmental Protection 

Agency, and demonstrate emission reductions by at least 40 percent, by weight, for 

SCAQMD 16 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

VOC and by at least 20 percent, by weight, for ammonia for combined finished 

compost cover and water application. 

For operations processing greater than 5,000 tons per year of foodwaste 

throughput: 

Emission Control Device

For greenwaste composting incorporating greater than 5,000 tons per year of 

foodwaste throughput (source-separated or mixed) on a facility wide basis, the 

operator would be required to install an emission control device for any active phase 

composting pile containing foodwaste amount of 10 percent or more, by weight. The 

emission control device would be required to have an overall system control 

efficiency of at least 80 percent, by weight, each for VOC and ammonia. Such 

equipment is required only for the 22 day active phase period of composting and not 

required for the curing phase. At the end of the first 22 day active phase composting, 

emissions are diminished over 90 percent4, 11, 12. Thus, requiring such control device 

for curing phase would not add significant emission reductions but may increase 

operational costs. The operator may implement a control alternative, if approved by 

the Executive Officer, California Air Resources Board, and the U.S. EPA, to achieve 

VOC and ammonia emission reductions equivalent to or greater than the required 

reductions. 

Any emission control device should be designed and operated such that an overall 

control efficiency of at least 80 percent is achieved for VOC and ammonia, 

respectively, from the baseline emission factors or alternate baseline emission factors. 

The overall control efficiency counts on both the capture efficiency and destruction 

efficiency. 

Even if the actual annual facility foodwaste throughput exceeds 5,000 tons per year, 

but the composting mix (or recipe) is less than 10 percent foodwaste, by weight, an 

emission control device would not be required. 

Baseline Emission Factors

For the purpose of this rule, baseline emission factors are proposed to determine an 

overall control efficiency of 80 percent for an emission control device. Baseline 

emission factors are the uncontrolled emission factors for greenwaste composting 

operations for VOC and ammonia. Proposed baseline emission factors are 4.25 

pounds of VOC per ton of throughput and 0.46 pounds of ammonia per ton of 

throughput for the active phase of composting only. Staff developed the composite 

emission factors by using currently available emissions data measured by various 

agencies, including the District, state and other air districts for greenwaste 

composting operations typical for the South Coast jurisdiction. The proposed 

emission factors reflect only emissions from windrow composting operations and 

exclude stockpile emissions. Procedures for developing the new baseline emission 

factors are explained in detail in Appendix III – Emission Reductions and Cost 

Effectiveness. 

SCAQMD 17 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Permit Application

A permit would be required for an emission control device for all new and existing 

greenwaste composting operations processing greater than 5,000 tons per year of 

foodwaste throughput (source-separated or mixed) and a foodwaste content 

containing 10 percent or more, by weight. All new greenwaste composting 

operations would be required to obtain a permit for such equipment before 

construction. Existing greenwaste composting operations that, as of rule adoption, 

process or plan to process greater than the foodwaste throughput and content 

thresholds would also have to file a permit application for an emission control device 

within three months of rule adoption and fully implement such device within six 

months upon approval of the permit application. However, based on the information 

provided by the composting operation, in response to the survey conducted by staff, 

there are no existing operations currently that are in excess of 5,000 tons of foodwaste 

per year. 

Depending on the configuration of the emission control device, controls may be 

accomplished with or without the need of venting the exhaust air to a separate air 

pollution control device, such as a biofilter. The configuration of such equipment 

should be described in detail in the permit application. 

Windrow composting does not require a permit. The AQMD permit requirements are 

specified in Rules 201 and 203, with permit exemptions specified in Rule 219. 

Generally, turning of a pile or windrow using DMV-registered motor vehicles does 

not require a permit. On-site equipment, such as dedicated mobile grinders and 

screeners, are already subject to permit from the District or ARB, but that is for the 

equipment or engine emissions only, not composting emissions. If a pile is aerated, 

the mechanical aeration system and its associated emission control device would 

require a separate permit for each. 

It should also be noted that depending on the circumstances, new and existing 

composting facilities modifying their operation may also be subject to New Source 

Review requirements of Regulation XIII, including BACT and offsets. New facilities 

with control devices permitted would be required to provide offsets for their full 

potential to emit, i.e. maximum after control of emissions up to levels allowed by 

their permit. If they keep their permitted levels of controlled emissions below the 4 

tons per year VOC threshold in Rule 1304(d), they will be exempt from the offset 

requirement. For existing facilities, no offsets would be required, provided no 

modification causes an increase in emissions. Even if the modification would result 

in an increase in emissions, the facility could take advantage of the small business 

exemption if its total emissions remain under the 4 tons per year threshold. Also, 

existing facilities are only required to offset the increase in emissions, or the amount 

in excess of the thresholds, if their pre-modification potential to emit was less than 

the amounts in Rule 1304(d). For purposes of this calculation, LEA permit limits on 

throughput will be considered to limit the source’s pre-modification potential to emit. 

Existing facilities required to install controls trigger the permit requirement, in which 

case they will be eligible for the offset exemption in Rule 1304(c)(4), provided there 

SCAQMD 18 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

is no increase in maximum rating as established in the facility’s LEA permit, 

otherwise only the net increase above the maximum rating need be offset. 

Source Testing

Under the proposed rule, all permitted emission control devices would be 

demonstrated through an approved source test for an overall control efficiency of at 

least 80 percent, by weight, for VOC and ammonia emissions, respectively. Source 

test needs to be conducted within three months after start-up of the device, or within 

nine months of permit approval, whichever occurs sooner, and every three years 

thereafter. Existing device already tested would need to conduct future source tests 

every three years from the initial source test. 

In the past, testing of biofilters has been recorded as costing several tens of thousands 

of dollars, but more recently there have also been full source tests performed for 

under $10,000. These tests have been successfully approved by AQMD Source 

Testing and also successfully met the 80% requirements for VOC and ammonia. As 

an example of an acceptable test to demonstrate and comply with PR 1133.3, a recent 

test on a biofilter for ammonia, VOC, as well as speciation testing by Method TO-15 

and reporting was conducted for ~$10,000. Most of the past tests that have the higher 

cost were research oriented tests that involved several operating scenarios, were 

developing testing methods and techniques, were unique and difficult to test 

configurations, and/or included many samples with no compositing done of any of the 

samples. As the testing firms gained experience with biofilter testing, and as more 

testers have entered the market for competition, the testing costs have gone 

down. Additionally, through experience in assessing these processes, more effective 

methodologies have been developed for planning and executing testing. 

Primary among the important factors responsible for adequate and lower cost testing 

is preliminary work to ensure representative samples, and the use of composite 

sampling. Biofilters tend, over time, to develop channeling and blockages to flow in 

certain areas. In order to account for these phenomena and to ensure that higher 

concentration areas, as well as lower, are not excluded in testing, biofilter surface area 

is divided into imaginary grids. The EPA “Measurement of Gaseous Emission Rates 

from Land Surfaces Using an Emission Isolation Flux Chamber User’s Guide” 

provides equations that can be used to determine grid size and quantity of grid points. 

Using these points, screening is performed with a portable organic vapor analyzer to 

determine the concentration profile of the biofilter surface. Smoke testing can help to 

identify channeling also, though resolution is obviously more limited than organic 

analysis screening. With screening information, specific points can be included in the 

actual testing to ensure that testing is representative. Often times, this screening can 

be used to reduce the number of sampling locations as would otherwise be required 

by the EPA User’s Guide requirements. Compositing several sample points into one 

pair of sample canisters or impingers succeeds in reducing lab testing cost. Also, in 

cases where biofilter inlet ducting flow rate can be determined by a routine Method 1-

4 Pitot traverse, accuracy is increased while testing costs are decreased by eliminating 

SCAQMD 19 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

the need for flux chamber sweep gas. These measures, taken together, ensure not 

only a representative sampling, but also cost efficiency. 

Operation and Maintenance

All permitted emission control devices should be installed, operated and maintained 

in accordance with the manufacturer’s operation and maintenance manual or other 

similar written materials supplied by the manufacturer or distributor to ensure proper 

operating conditions. 

Proper operation and maintenance would be required for an emission control system 

to ensure maximum emissions control. Installation, operation and maintenance should 

be in accordance with the manufacturer’s operation and maintenance manual or other 

similar written guidelines supplied by the manufacturer or the distributor of an 

emission control device to ensure that the control device remains in proper operating 

condition. 

Test Methods and Protocol 

For operations subject to the requirements of an air pollution control device, the operator 

of a greenwaste composting operation would be required to conduct all required source 

and laboratory tests using the Executive Officer approved test protocol developed in 

accordance with the guidelines provided in Attachment A of PR 1133.3. A District 

approved laboratory must be used for the associated tests. 

Recordkeeping 

All operational and informational records, including operation and maintenance of the 

aeration and control system and source tests, should be maintained for the prior five years 

of operation, with the most recent two years retained at the facility, which shall be 

immediately available to the Executive Officer upon request. The remaining three years 

of records shall be made available to the Executive Officer within one week of request. 

Exemptions 

• Composting facilities subject to Rule 1133.2 – Emission Reductions from CoComposting Operations, are exempt from the provisions of this rule. 

• If the operator of any greenwaste composting operation voluntarily installs an 

emission control device, the provisions of additional irrigation and the finished 

compost cover and associated recordkeeping requirements do not apply. 

• To be consistent with exemptions in Rule 1133 – Composting and Related 

Operations – General Administrative Requirements, the following type of 

facilities and operations are exempt from the provisions of PR 1133.3, provided 

that the operator is not subject to the Local Enforcement Agency Notification or 

Permit regulations pursuant to Title 14 Division 7, Chapter 3.1, Section 17857.1 

of the CCR: 

o Community composting 

o Nursery composting 

o Backyard composting 

SCAQMD 20 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

o Recreational facility composting 

EMISSIONS INVENTORY AND REDUCTIONS 

Affected Industry 

Chipping and Grinding Industry Sector

For the purpose of PAR 1133.1, chipping and grinding activity is defined as an activity 

that mechanically reduces the size of greenwaste, woodwaste, or foodwaste, using 

chippers and/or tub grinders. Chipping and grinding activities can be stand-alone 

operations, or part of multi-operation facilities, such as a transfer station, a landfill, a 

material recovery operation, or a composting operation, that handle multiple incoming 

material streams with separate operating areas within the same facility. 

Chipping and grinding facilities process greenwaste, which is mostly collected from 

landscapers or from cities’ curbside collection programs. Curbside greenwaste is 

collected from receptacles designed for residential household greenwaste, and is mainly 

composed of grass clippings and weeds and may also contain other putrescible wastes 

(e.g., foodwaste). Non-curbside greenwaste is greenwaste that is not collected from 

curbside programs and mainly contains tree trimmings and other landscaping greenwaste. 

For the purpose of PAR 1133.1, the large woody material of tree trimmings exceeding 

two inches in any dimension is considered woodwaste. 

District staff worked closely with stakeholders and CalRecycle staff to estimate the 

number of facilities that have chipping and grinding operations. Table 1 shows the 

estimated number of chipping and grinding facilities. These facilities may be stand-alone 

facilities or co-located at MRFs, landfills or composting facilities. 

There is a broad market for chipped or ground greenwaste where they can be used as 

mulch for landscaping, ADC at landfills, biofuels for energy production, feedstock for 

static pile or greenwaste composting operations, or bulking agents for manure and/or 

biosolids composting. All new and existing greenwaste chipping and grinding operations 

would be covered by PAR 1133.1. Agricultural chipping and grinding, woodwaste 

chipping and grinding, landclearing chipping and grinding, palm chipping and grinding, 

and portable chipping and grinding activities would continue to be exempt from PAR 

1133.1 and thus would not be affected. 

Table 1. Estimated Number of Chipping and Grinding Facilities 

County Number of 

facilities 

Number of 

landfills (subset) 

Estimated landfill ADC 

throughput1

 (subset) (tons) 

Los Angeles 24 5 454,000 

Orange 18 3 580,000 

Riverside 17 3 103,000 

San Bernardino 11 3 37,000 

Total 70 14 1,174,000 

1

 2009 tons (source: Horowitz, CalRecycle). 

SCAQMD 21 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Staff is appreciative of the input provided by the compost industry. Without adequate 

assistance from the compost industry stakeholders, staff would not be able to estimate or 

update the accurate greenwaste chipping and grinding throughput. 

Greenwaste Composting Industry Sector

Staff developed an industry profile for the greenwaste composting operations based on 

several resources. Those resources include the SWIS database, District Rule 1133 

Registration/Annual Update database, the District’s Air Quality Notification Report, a 

District-wide composting survey (conducted in 2007), a supplemental questionnaire to 

augment the 2007 survey, site visits, phone calls/emails to the facility operators, and 

personal communications with CalRecycle and LEA staff. 

Staff conducted a survey of greenwaste composting operations in the South Coast 

jurisdiction in 2007. The survey was conducted as a tool to update the inventory for the 

greenwaste composting industry relying on the extension of Rule 1133 Facility 

Registration. Initially, the survey focused on the facility total incoming tonnage of green 

materials, along with operational practices (i.e., composting parameters). The surveyed 

facility total incoming throughput was 692,000 tons per year for 15 greenwaste 

composting facilities. The operational status of the facilities, the number of greenwaste 

composting facilities and actual throughput for greenwaste composting operations was 

refined for 2009–2010. 

Currently, 17 facilities are identified as greenwaste composting facilities and their actual 

tons per year throughput for greenwaste composting are shown in Table 2. Actual 

greenwaste throughput for composting operations is about 416,300 tons for 2009–2010, 

which accounts for 58% of facility throughput totals for the same time period. About half 

of the 17 affected greenwaste composting facilities have multiple operations to produce 

materials other than compost, including, but not limited to, mulch, daily cover materials 

at landfills, biofuel for a biomass power generation facility, and palm feedstock. 

Table 2. Number and Throughput of Affected Greenwaste Composting Facilities 

County Number of 

facilities 

Facility throughput totals 

(tons/year) 

Throughput for 

composting (tons/year) 

Los Angeles 4 169,660 100,150 

Orange 7 447,940 247,460 

Riverside 4 93,220 60,830 

San Bernardino 2 7,860 7,860 

Totals 17 718,680 416,300 

Emissions Inventory and Reductions 

The emissions inventory for greenwaste composting operations was developed based on 

the refined 2009–2010 activity data (i.e., actual annual throughput of greenwaste 

processed for composting) and baseline emission factors for windrow composting. The 

baseline emission factors for both VOC and ammonia were developed based on the 

SCAQMD 22 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

emission tests conducted by the District, other air districts, and CalRecycle for 

greenwaste windrow composting operations. 

Windrow composting baseline (uncontrolled) emissions are calculated for both the active 

and curing phases of composting, and thus emission factors used are 4.67 pounds per wet 

ton of throughput for VOC and 0.66 pounds per wet ton of throughput for ammonia, 

which includes emissions from the active and curing phases of composting. Total 

baseline emissions were then estimated by multiplying the total actual composting 

throughput by these emission factors. However, emission reductions were calculated 

only for the active phase of composting. Thus, emission factors for the active phase of 

composting are 4.25 pounds per wet ton for VOC and 0.46 pounds per wet ton for 

ammonia. Emission reductions were calculated with the latter emission factors, as well 

as overall control efficiencies of mitigation measures. 

Table 3 provides the emissions inventory for greenwaste composting operations, as well 

as the emission reductions anticipated with the implementation of PR 1133.3. 

Calculation details are explained in Appendix III. As shown in Table 3, greenwaste 

composting operations generate significant amount of VOC and fewer amounts of 

ammonia emissions in the Basin. Using the baseline VOC emission factors and assumed 

percent emission reductions with the use of surface irrigation and finished compost cover 

during the 15 day active phase period of the windrow composting process, 0.9 tons of 

VOC and 0.1 tons of ammonia are projected to be reduced daily. 

Table 3. Emissions Inventory and Emission Reductions for Existing Greenwaste 

Composting Operations 

VOC Ammonia 

Emissions Inventory (tons/day) 2.66 0.38 

Proposed Requirements 

Windrow composting operations 

(without emission control devices) 

40% with compost cover and 

water combined 

20% with compost cover 

and water combined 

Emissions Reduction (tons/day) 0.88 0.05 

COST EFFECTIVENESS 

Cost effectiveness was analyzed, and is presented in Table 4, based on the total 

throughput of greenwaste processed for composting operations. Total compliance costs, 

being averaged per facility, are also presented. The cost effectiveness would be $1,340 

for ton of VOC-only emissions reduced and $1,270 for ton of VOC and ammonia 

combined emissions reduced. This cost effectiveness was estimated based on the 

compliance costs calculated for finished compost cover and watering. According to the 

phone survey with the operators of affected composting facilities, some facilities use all 

potable water and the others use all reclaimed or canal or well water. The different costs 

of potable or reclaimed, or other water use were reflected in the cost effectiveness 

calculation. The total costs and assumptions used in this analysis are explained in detail 

in Appendix III. Costs are proportional to throughput of greenwaste processed and range 

from $700 to ~$200,000 per year depending on the facility. This figure is based on a 

compliance cost of $1.15 per ton of processed throughput. 

SCAQMD 23 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Table 4. Greenwaste Composting Average Cost Effectiveness 

Composting 

throughput 

(Tons/year)

Number 

of 

facilities

Mitigation 

measure

description

Total annual 

compliance 

costs 

(Avg. $/year)

Cost 

effectiveness 

for VOC only 

($/ton)

Cost 

effectiveness for 

VOC & NH3

($/ton)

416,300 17 

Finished compost 

cover and watering 

combined

$29,000 $1,340 $1,270 

INCREMENTAL COST EFFECTIVENESS 

Health and Safety Code Section 40920.6 (a)(3) requires the calculation of incremental 

cost effectiveness for potential control options, when the District adopts “rules or 

regulations to meet the requirements for best available retrofit control technology 

(BARCT) pursuant to Sections 40918, 40919, 40920 and 40920.5, or for a feasible 

measure pursuant to Section 40914...” All of these referenced laws are contained in 

Chapter 10, which deals with district plans to “achieve and maintain state ambient air 

quality standards for ozone, carbon monoxide, sulfur dioxide and nitrogen dioxide...” 

Incremental cost effectiveness is intended to measure the change in costs, in dollars per 

year, and emission reductions, in tons of VOC or ammonia reduced per year, between 

two progressively more effective control technologies. Incremental cost effectiveness 

examines additional costs and emission reductions that can be achieved by adding a 

second level of control to the primary control. Because the incremental reductions from 

the controlled source operations are typically low, incremental cost effectiveness 

produces a much higher cost-to-reduction ratio than the primary control and thus should 

not be compared to the cost effectiveness value. The use of an air pollution control 

device has long been conceptualized for composting involving foodwaste, but capital 

expenditures for low throughput facilities are cost-prohibitive. Therefore, staff proposes 

to require such controls for those facilities processing significant quantities of foodwaste 

(i.e., greater than 5,000 tons per year). No existing facility operations are expected to 

trigger this control requirement, although it should be noted that two facilities are known 

presently to be in preparation to receive foodwaste in excess of 5,000 tons per year, but 

those facilities are already planning on air pollution control device installation. 

Incremental costs and emission reductions were examined between the windrow 

composting with combined mitigation measures of finished compost cover and watering, 

and an emission control device required if the facility receives more than 5,000 tons per 

year foodwaste and whose composting content exceeds 10 percent, by weight. A forced 

aeration system equipped with emission control is considered the typical emission control 

device for this comparison. The control device is assumed to have a lifetime of 10 years 

and an overall control efficiency of 80 percent. Incremental costs and emission 

reductions were calculated for an operation with 50,000 tons throughput per year. 

Incremental costs were calculated to be $2,677,000 and incremental emission reductions 

were to be 420 tons (per 10 years) for VOC (480 tons for VOC and ammonia combined). 

Incremental cost effectiveness was then calculated to be $6,600 per additional ton of 

VOC-only ($5,700 per additional ton of VOC and ammonia combined). As opposed to 

SCAQMD 24 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

absolute cost effectiveness of using finished compost cover and watering for this 50,000 

tons throughput operation, which was $1,340 per ton of VOC-only ($1,270 per ton of 

VOC and ammonia combined), incremental cost effectiveness was more than four times 

higher. High increases are caused by relatively high cost increments, as opposed to the 

relatively small incremental emission reductions between the two control methods. 

Although $6,600 per ton incremental cost effectiveness is in the range of other adopted 

rules, the operating margin for greenwaste composting facilities is relatively low and with 

the seemingly high capital expenditure required for control equipment, the use of controls 

is not more widely proposed so as to not impact facility compliance/SB939 diversion 

goals. 

ENVIRONMENTAL ASSESSMENT 

Pursuant to the California Environmental Quality Act (CEQA) and SCAQMD Rule 110, 

a Draft Environmental Assessment (DEA) has been prepared to analyze any potential 

adverse environmental impacts associated with PAR 1133.1 and PR 1133.3. The CEQA 

document was released for a 30 day public review and comment on June 2, 2011, and is 

available at AQMD Headquarters, by calling the AQMD Public Information Center at 

(909) 396-2039, or by accessing AQMD’s CEQA website at: www.aqmd.gov/ceqa. 

Close of the comment period is July 1, 2011. 

SOCIOECONOMIC ASSESSMENT 

The Socioeconomic Analysis is being conducted and will be made available to the public 

at least 30 days prior to the Public Hearing. 

COMPARATIVE ANALYSIS 

Health and Safety Code Section 40727.2 was added in 1997 as part of AB 1061 

(Machado). The statute prescribes the analysis that needs to be conducted to support a 

statutory mandated finding of non-duplication, which must be made by the district board 

prior to adopting, amending, or repealing a rule. The analysis requires an identification 

of “all existing federal air pollution control requirements” including best available control 

technology (BACT) as well as “any existing or proposed [district] rules and regulations” 

that apply to the “same operations or source type” as proposed to be regulated by the rule. 

The District’s analysis must also examine “all air pollution control requirements and 

guidelines” that the District is initially informed of by the public that also apply to the 

same operations or source type. 

AQMD Rule 403 – Fugitive Dust establishes the amount of PM entrained in the air as a 

result of man-made activity capable of generating fugitive dust. While PM emissions 

have not been measured from composting and related operations (e.g., chipping/grinding, 

screening, storing, etc.), greenwaste chipping and grinding operations subject to PAR 

1133.1 and greenwaste composting operations subject to PR 1133.3 will also need to 

comply with Rule 403. 

SCAQMD 25 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

SCAQMD 26 July 2011 

AQMD Rule 1133 – Greenwaste and Related Operations – General Administrative 

Requirement, is applied to chipping/grinding and composting facilities. It establishes 

one-time registration, along with one-time registration fee, and annual update 

requirements. Therefore, PAR 1133.1 and PR 1133.3 facilities continue to comply with 

Rule 1133. 

AQMD Rule 1133.1 – Chipping and Grinding Activities, establishes holding and 

processing time requirements for different types of greenwaste and foodwaste to prevent 

inadvertent decomposition. Current Rule 1133.1 currently allows holding times before 

being chipped or ground of 3 days for curbside, 14 days for non-curbside, and 7 days for 

mixed. However, the rule only requires three-day retention time for curbside greenwaste 

after being chipped or ground, while there is no such holding time requirement for noncurbside and mixed chipped or ground greenwaste. PAR 1133.1 proposes to add the 

same 48 hours holding requirement all for curbside, non-curbside and mixed chipped and 

ground greenwaste. 

AQMD Rule 1133.2 – Emission Reductions from Co-Composting Operations, is applied 

only to co-composting operations (biosolids and/or manure mixed with bulking agents). 

It establishes control requirements for new and existing co-composting facilities. Rule 

1133.2 facilities and operations are exempt from the requirements of PR 1133.3. 

PR 1133.3 will add new requirements, and no conflict with existing requirements is 

anticipated. 

Other federal, state and local requirements have been summarized on pages 5–7 of this 

staff report. Table 5 compares PAR 1133.1 and PR 1133.3 with the most relevant 

requirements of CCR Title 14. 
PAR 1133.1 and PR 1133.3 

Table 5. Comparison of State Regulation and District Proposed Rules 

Title 14, CCR, Chapter 3.1 – Composting Operations Regulatory Requirements PAR 1133.1 

Article 1. General Subdivisions (a) Purpose, (b) Applicability & (c) Definitions Subdivisions Section 17850 

Scope (c) 

Establishes standards and regulatory requirements for intentional and inadvertent composting resulting from the handling of compostable materials, IBNLT feedstock, compost, or chipped and ground materials 

Purpose (a) 

Prevent inadvertent decomposition occurring during chipping and grinding activities, including stockpile operations 

Purpose (a) 

Applicability 

(b) 

Operators of chipping and grinding activities to produce materials other than active or finished compost 

Applicability (b) 

Definitions Section 17852 

Active compost (a)(1) 

Compost feedstock: • Generating T at ≥ 122 deg F; or • Releasing CO2 ≥ 15 mg/g compost/day, or the 

equivalent of O2 uptake 

Definitions: Active compost (c)(1) 

• Material in the process of being rapidly 

decomposed and is biologically unstable 

• Generates T at ≥ 122 deg F • IBNLT pathogen-reduced mulch 

Definitions: Active compost (c)(1) 

Chipping 

and grinding operations and facilities (a)(10) 

An operation or facility that: • Do not produce compost; or 

• Mechanically reduces the size; or otherwise • Engages in the handling of compostable material 

Chipping and grinding (c)(3) 

Any activity that mechanically reduces the 

size of greenwaste, woodwaste, and/or foodwaste 

Active phase (c)(2) 

(a)(10)(A)1. Handles only material, excluding manure, allowed at a 

green material composting op. or fac. set forth in 17852(a)(22) 

N/A 

(a)(10)(A)2. • Each load of green material is removed from the site 

within 48 hrs of receipt 

• The EA may allow a site to keep it on-site for up to 7 

days 

Refer to PAR 1133.1 Requirements 

(a)(10)(B) If the contaminant limits in 17852(a)(21) are exceeded, 

shall be regulated as set forth transfer/processing requirements 

N/A 

(a)(10)(C) If green material remains on-site for >48 hrs, shall be 

regulated as a compostable material handling operation or facility 

N/A 

Compostable 

material (a)(11) 

Any organic material that when accumulated will become active compost 

Greenwaste 

composting (c)(13) 

Compostable 

material handling operation or facility (a)(12) 

An operation or facility that: • Processes, transfers, or stores compostable material, 

resulting in controlled biological decomposition 

• Handling includes composting, screening, chipping and 

grinding, and storage activities related to the production of compost, compost feedstocks, and chipped and ground materials 

Composting 

(c)(6) 

SCAQMD 28 
PAR 1133.1 and PR 1133.3 

Table 5. Comparison of State Regulation and District Proposed Rules (continued)

Title 14, CCR, Chapter 3.1 – Composting Operations Regulatory Requirements PAR 1133.1 

Article 1. General (cont’d) Subdivision (c) Definitions Subdivision Definitions Section 17852 

Curing (a)(13) 

Final stage of the composting process: • Occurs after compost has undergone pathogen reduction 

& after most of the readily metabolized material has been decomposed and stabilized 

Finished compost (c)(7) 

Humus-like material that results from the controlled biological decomposition of organic waste materials and is biologically stable 

Finished compost (c)(10) 

Disposal 

(a)(15)(A) 

Stockpiling of: • Compostable material onto land for a combined period of 

time > 6 mos., or agricultural and green material for 12 mos. on prime agricultural land N/A 

Curing phase  (c)(7) 

(a)(15)(B) Does not include the use of compostable material for ADC 

at a solid waste landfill (Title 27, section 20680) N/A 

(a)(15)(C) Does not include land application of compostable organic 

material Land application – application of compostable material (excl. food or mixed solid waste) to forest, agricultural, and 

range land, I/A/W CDFA requirements for beneficial uses 

N/A 

Feedstock 

(a)(19) 

• Any compostable material used in the production of 

compost or chipped and ground material IBNLT agricultural material, green material, food material, biosolids, and mixed solid waste 

• Additives or amendments are not considered feedstocks 

Stockpile (c)(17) 

• A supply of raw material tipped and stored 

prior to be utilized on-site or removed from the site 

• Raw materials before and after chipping 

and grinding are also included 

Food material (a)(20) 

Any material that: • Was acquired for animal or human consumption • Is separated from the municipal solid waste stream • Does not meet the definition of “agricultural material” • May include material from food facilities [H&SC 

113785], grocery stores, institutional cafeterias or residential food scrap collection 

Foodwaste (c)(8) 

• Any food scraps collected from the food 

service industry, grocery stores, or residential food scrap collection 

• Includes food scraps that are chipped and 

ground 

Foodwaste (c)(11) 

SCAQMD 29 
PAR 1133.1 and PR 1133.3 

Table 5. Comparison of State Regulation and District Proposed Rules (continued)

Title 14, CCR, Chapter 3.1 – Composting Operations Regulatory Requirements PAR 1133.1 

Article 1. General (cont’d) Subdivision (c) Definitions Subdivision 

Green 

material (a)(21) 

Any plant material that is: • Separated at the point of generation • Contains no greater than 1% of physical contaminations, 

Wt. 

• IBNLT yard trimmings, untreated wood wastes, natural 

fiber products, and C&D wood waste 

• Does not include food material, biosolids, mixed solid 

waste, material processed from commingled collection, wood containing lead-based paint or wood preservative, mixed construction or mixed demolition debris 

Curbside greenwaste (c)(5) 

• Collected from receptacles designated for 

residential household greenwaste 

• Screened curbside greenwaste containing 

only grass clippings, leaves, and/or twigs that is not considered non-curbside greenwaste as defined in paragraph (c)(11) 

Mixed greenwaste (c)(10) 

Curbside greenwaste comingled with noncurbside 

Noncurbside greenwaste (c)(11) 

• Any greenwaste not collected from 

receptacles designated for residents 

Compost overs (c)(5) 

• Oversized woody materials that do not 

decompose in a typical composting cycle and are screened out of finished product at the end of composting 

• Have been through pathogen reduction 

process outlined in the Title 14, Section 17868.3 

Compost overs (c)(7) 

Green 

material composting op. or fac. (a)(22) 

An operation or facility that: • Composts green material, additives, and/or amendments • May also handle manure or paper products N/A 

Wood waste 

(a)(42) 

Solid waste consisting of wood pieces generated from: manufacturing or production of wood products, harvesting, processing or storage of raw wood materials, or C&D activities 

Woodwaste (c)(16) 

Lumber, and the woody material portion (> 2 inches) of mixed demolition and construction wastes, tree trimmings, branches, tree trunks, stumps, and limbs 

Woodwaste (c)(25) 

Yard 

trimmings (a)(43) 

Any wastes generated from the maintenance or alteration of public, commercial or residential landscapes IBNLT yard clippings, leaves, tree trimmings, prunings, brush, and weeds 

Greenwaste (c)(7) 

• Any organic waste material generated 

from gardening, agriculture, or landscaping activities IBNLT grass clippings, leaves, tree and shrub trimmings, and plant remains 

• Includes curbside, non-curbside, and 

mixed greenwaste 

Greenwaste (c)(12) 

SCAQMD 30 
PAR 1133.1 and PR 1133.3 

Table 5. Comparison of State Regulation and District Proposed Rules (continued)

Title 14, CCR, Chapter 3.1 – Composting Operations Regulatory Requirements PAR 1133.1 

Article 2. Regulatory Tiers for Composting Operations and Facilities Subdivisions (f) Exemptions Subdivisions Section 17854 

Composting materials handling facility permit 

All compostable materials handling activities shall obtain a Compostable Materials Handling Facility Permit 

N/A 

Section 17855 

Excluded activities 

• Agricultural material derived on-site and used on-site • Vermicomposting • Mushroom farming • Handling of green material, feedstock, additives, 

amendments, compost, or chipped and ground material, if: o ≤ 500 cy is on-site at any one time; o Compostable materials* are generated on-site; and o ≤ 1,000 cy of materials are either sold or given away 

annually 

* Compostable material may include up to 10% food, vol. • Handling of compostable materials, if: 

o The activity is co-located at a facility (i.e. landfill or 

transfer/processing facility) that has a tiered or full 

permit as defined section 18101; etc. 

• Non-commercial composting with < 1 cy food material 

generated and used on-site 

• Storage of bagged products (≤ 5 cy) from compostable 

material 

• Within-vessel composting process < 50 cy capacity 

• Beneficial use of compostable materials IBNLT: 

o Slope stabilization, weed suppression, ADC, and 

similar uses, determined by the LEA 

o Land application [Food & Ag. Code 14501] o Reclamation projects [Public Resrc. Code 2770] 

Exemptions (f) 

• Exempt from (d)(2) through (d)(4): 

o C/G activities of greenwaste derived 

from the site and utilized on-site, provided < 1,000 cy of material is sold or given away 

o Portable, agricultural, landclearing, 

woodwaste, and palm C/G activities 

• Chipped and ground curbside greenwaste: 

Exempt from the requirements of paragraph (d)(2) provided that the MC is < 30%, measured I/A/W subdivision (e) and the MC measurements are maintained onsite in accordance with subparagraph (d)(4)(E) 

• The operator of a landfill or biomass 

power generation facility: Exempt from the requirements of paragraph (d)(6), provided that the operator does not perform C/G of greenwaste on-site 

• The operator of a biomass power 

generation facility or a facility to produce biofuel for a biomass power generation facility: Exempt from (d)(2), provided T is < 122 deg F. or MC is < 30%, measured I/A/W subdivision (e) and the MC measurements are maintained on-site in accordance with subparagraph (d)(4)(E) 

Exemptions (g) 

SCAQMD 31 
PAR 1133.1 and PR 1133.3 

Table 5. Comparison of State Regulation and District Proposed Rules (continued) 

Title 14, CCR, Chapter 3.1 – Composting Operations Regulatory Requirements PAR 1133.1 

Article 2. Regulatory Tiers for Composting Operations and Facilities (cont’d) Subdivision (d) Requirements Subdivision Section 17857.1 

Green material composting operations and facilities 

• EA Notification requirements: 

o Has > 12,500 cy of feedstock on-site at any one time o Inspection at least once every 3-months 

• Compostable Materials Handling Facility Permit: 

o Has > 12,500 cy of feedstock on-site at any one time 

N/A 

Food material 

Must have a composting operation or a transfer station permit to receive food material (per Horowitz, CalRecycle) 

N/A 

Foodwaste (d)(1) 

Cannot take it unless allowed by the LEA to handle foodwaste 

Foodwaste (d)(1)(B) 

Section 17862.1 

Chipping and grinding operations and facilities 

• EA Notification requirements: 

o Receives up to 200 tpd 

• Registration Permit: 

o Receives > 200 tpd and up to 500 tpd 

• Compostable Materials Handling Facility Permit: 

o Receives > 500 tpd 

• A chip/grind operation is not subject to 17868.1 through 

3 

• If a chip/grind operation exceeds 1% contamination 

limits, it shall be regulated as set forth in Transfer/Processing Regulatory requirements 

• If a chip/grind operation stores material for > 48 hrs, the 

site shall be regulated as a green material handling operation or facility 

Curbside, noncurbside, and mixed greenwaste (d)(2) 

Chip or grind and utilize on-site, or remove from the site within 48 hours of receipt, excluding observance of official federal and state holidays, or up to 7 days maximum, with approval from the LEA 

Greenwaste (d)(1)(A) 

SCAQMD 32 
PAR 1133.1 and PR 1133.3 

Table 5. Comparison of State Regulation and District Proposed Rules (continued) 

Title 14, CCR, Chapter 3.1 – Composting Operations Regulatory Requirements PAR 1133.1 

Article 8 Composting Operation and Facility Records Subdivisions (d) Requirements and (e) Moisture Content Subdivision Section 17869 

General record keeping requirements 

All compostable materials handling operations and facilities shall record the following: • Any special occurrences encountered during operation 

and methods used to resolve problems 

• Any public complaints, including: 

o The nature of the complaint; o The date the complaint was received; o The name, address, and ph.# of the complainer; and o Any actions taken to respond to the complaint 

• The quantity and type of feedstock received and quantity 

of compost and chipped/ground material produced 

• Keep all records in one location and accessible for 5 

years and available for inspection by authorized representatives during normal working hours 

• The number of load checks and loads rejected 

• All test results IBNLT metal contaminations, fecal 

coliforms/Salmonella sp. Densities, T measurements, & dates of windrow turnings o Retain records detailing pathogen reduction methods 

• Any serious injury to the public occurring on-site and 

any complaint of adverse health effects to the public 

attributed to operations 

Recordkeeping (d)(3) 

• Maintain all the operational records for the 

prior 5 yrs. of operation, with the most recent 2 yrs. retained at the facility, which shall be immediately available upon request by the EO 

• Remaining 3 yrs. of records shall be made 

available to the EO within 1 week of request 

Recordkeeping (f) 

Records (d)(4) 

Maintain the following on-site for 2 years: • (A) AQMD registration and annual 

updates 

• (B) Date, type, and amount of greenwaste 

and/or foodwaste received 

• (C) Date, type, amount of greenwaste 

and/or foodwaste removed from the site location where they are transferred to 

• (D) Dates of rainy days and wet weather 

conditions and description of specific conditions that limited normal operations 

• (E) T or MC measurements • (F) Dates and amount of curbside 

greenwaste chipped and ground 

N/A 

Rainy days and wet weather conditions (d)(5) 

Time requirements in paragraph (d)(2) may be extended by the number of rainy days and wet weather conditions that impede normal chipping and grinding operations provided that records are maintained in accordance with subparagraph (d)(4)(D) 

N/A 

Moisture content measurement (e) 

• Determine by collecting at least 10 

samples of chipped and ground greenwaste from various locations of the pile 

• At a depth of at least 12 inches below pile 

surface 

• Mix thoroughly and analyze for moisture 

content by ASTM method D4442, ASTM method D4444 or ASTM method E871-82 

SCAQMD 33 
PAR 1133.1 and PR 1133.3 

SCAQMD 34 

Table 5. Comparison of State Regulation and District Proposed Rules (continued)

Title 14, CCR, Chapter 3.1 – Composting Operations Regulatory Requirements PAR 1133.1 

Article 6. Composting Operation Standards Section 17867 

General requirements 

• Random road checks; 

• Traffic flow and human access control; 

• Post legible signs at public entrances; • Fire prevention and control measures; • Ventilation of enclosed operations and facilities; 

• Leachate control; 

• Attendant on duty during business hours/open to public; • Prevent human injury, etc. 

N/A 

Article 7. Environmental Health Standards Section 17868.3 

Pathogen reduction 

• Operators that produce compost shall ensure the 

following: o Enclosed or within-vessel, active compost: 

– Maintain T at ≥ 131 deg F for 3 days 

o Windrow composting, active compost: 

– Maintain T at ≥ 131 deg F for 15 days or longer – Minimum of 5 turnings 

o Aerated static pile, active compost: 

– Cover with 6–12 inches of insulating material 

– Maintain T at ≥ 131 deg F for 3 days or longer 

• Alternative, equivalent pathogen reduction method • Monitoring during the pathogen reduction period: 

o Each day, at least one T reading per every 150 ft 

windrow, or for every 200 cy of active compost – 12–24 inches below the pile surface for windrow 

composting 

– 12–18 inches below the point where the insulation 

cover meets the active compost for aerated static pile 

N/A 

Acronyms: ADC: alternative daily cover I/A/W: in accordance with CCR: California Code of Regulations IBNLT: includes, but is not limited to; or including, but not limited to 

CDFA: California Department of Food and Agriculture LEA: Local Enforcement Agency C&D: construction and demolition MC: moisture content CDI: construction, demolition, and inert PAR: Proposed Amended Rule C/G: chipping and grinding PR: Proposed Rule CST: composting SMI: Solvita Maturity Index® EO: Executive Officer T: temperature 
PAR 1133.1 and PR 1133.3 Final Staff Report 

CONCLUSIONS 

The proposed rules reflect reasonable, cost-effective mitigation measures for reductions in 

VOC and ammonia emissions from chipping and grinding, and greenwaste composting 

operations. 

The proposed amendments to Rule 1133.1 would generate negligible compliance costs 

because they reflect existing requirements in Title 14 of the CCR. Although the proposed 

amendments are more restrictive than existing Rule 1133.1, there would be no impacts, as the 

changes codify what the operators are doing now to comply with CCR, Title 14 requirements 

as enforced by the LEA. 

Compliance costs associated with the implementation of PR 1133.3 would include the O&M 

costs for applying one-time finished compost and additional watering to compost piles during 

the first 15 days of the active phase of composting. Costs for potable and reclaimed water, 

and labor were considered. Capital cost for the equipment to apply finished compost cover 

was not considered as such equipment already exists at the facilities. Total annual O&M 

costs range from $700 per facility to $200,000 per facility with a facility average of $29,000 

per year. The compliance cost per ton of throughput is $1.15 per ton for adding an initial 

finished compost cover and watering before each turning. 

Implementation of PR 1133.3 is estimated to reduce 0.9 tons of VOC and 0.1 tons of 

ammonia per day from 17 existing greenwaste composting facilities. Overall average cost 

effectiveness would be approximately $1,270 per ton of VOC and ammonia combined 

emissions reduced (or $1,340 per ton of VOC-only emissions reduced). 

SCAQMD 35 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

SCAQMD 36 July 2011 

REFERENCES 

1. USEPA, 2008. Inventory of US Greenhouse Gas Emissions and Sinks: 1990–2006, EPA 

Report 430-R-08-005, U.S. Environmental Protection Agency, April 2008. 

2. Brown, M.R, 2007. California links organics recycling to sustainable future. BioCycle, 

48, 20–22. 

3. SJVAPCD, 2010a. Comparison of Mitigation Measures for Reduction of Emissions 

Resulting from Greenwaste Composting, Project 09-01 CCOS Draft Final Report. 

4. CIWMB, 2007. Emissions Testing of Volatile Organic Compounds from Greenwaste 

Composting at the Modesto Compost Facility in the San Joaquin Valley, Contractor’s 

Report to the California Integrated Waste Management Board, October 31, 2007. 

5. CalRecycle, 2010. An Investigation of the Potential for Ground-Level Ozone Formation 

Resulting from Compost Facility Emissions, Contractor’s Report to the California 

Department of Resources Recycling and Recovery, December 2010. 

6. Govind, R, 2009. Biofiltration: An Innovative Technology for the Future, PRD Tech, Inc. 

White Paper. 

7. SCAQMD, 2003. Final Staff Report for Proposed Rule s1133, 1133.1 and 1133.2, South 

Air Quality Management District, January 2003. 

8. Engineered Compost Systems (ECS), www.compostsystems.com/ac_composter.html, 

accessed in 2010. 

9. GORE® Cover, www.gore.com/en_xx/products/fabrics/swt/index.html, accessed in 

2010. 

10. Managed Organic Recycling, Inc., www.odorfreecompost.com/topics/technology, 

accessed in 2010. 

11. SJVAPCD, 2010b. Compost VOC Emission Factors, San Joaquin Valley Air Pollution 

Control District, September 15, 2010. 

12. NorCal Waste Systems, 2006. Emissions Evaluation of Complete Compost Cycle VOC 

and Ammonia Emissions, Air Emissions Source Test Report, May 2006. 
PAR 1133.1 and PR 1133.3 Final Staff Report 

APPENDIX I – COMPOSTING PROCESS 

This appendix describes basic steps and management requirements for greenwaste composting 

operations. This part of the document includes discussion on the definition of composting, the 

typical greenwaste composting operation, and operating parameters of composting conditions 

taken into consideration for efficient composting operation. 

Composting is a biological process where microorganisms decompose organic materials under 

controlled environments. The readily available nutrients of the feedstock materials are 

consumed by microorganisms. Microorganisms use carbon for energy and growth while 

nitrogen is essential for protein and reproduction. As a result of the decomposition by the 

microorganisms, the feedstock is reduced to about one-half of the original volume. Figure I-1 

describes the composting process. In order for the microorganisms to function properly, enough 

moisture and oxygen are required, as well as a balance of nutrients. 

Figure I-1. Composting Process1

Greenwaste composting consists of three stages: preprocessing, processing and postprocessing. 

Figure I-2 presents the flow of a typical greenwaste composting process. 

Figure I-2. Flow of Typical Greenwaste Composting Operation2 

SCAQMD I-1 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

The preprocessing stage involves sorting and shredding (grinding and chipping) greenwaste 

collected and unloaded. After being preprocessed, greenwaste undergoes active composting 

during which thermophilic microorganisms (or thermophiles) decompose the readily available 

nutrients. The curing stage takes place when materials are stable, and the remaining nutrients are 

further degraded by mesophilic microorganisms (or mesophiles) that are still present. The 

finished compost may be screened again before use as a soil amendment or conditioner during 

the postprocessing stage. 

Preprocessing Stage 

1. The green materials should be first screened to get rid of uncompostable materials, such 

as plastic bags, and shredded to allow a large surface area on which the microorganisms 

can consume nutrients quickly and easily. The size of the shredded materials, however, 

should be large enough so as not to pack the materials too tightly, which limits the 

movement of air through the pile and thus may result in anaerobic conditions2. Although 

the material size varies, it generally ranges from 0.125 inch to 3.0 inches. 

2. Once screened and shredded, water is added to the greenwaste to obtain the preferred 

moisture content of 40% – 60%2-7. If the pile is too wet, dry materials are added to 

decrease the moisture content or aeration is provided to evaporate excess water that may 

result in anaerobic conditions. 

Processing Stage 

3. The feedstock is formed into windrows (for the turned windrow system). The ideal 

height of the windrow is 5–6 feet to allow the composting materials to be insulated 

properly but to prevent the buildup of excessive heat inside the pile. Windrow heights 

vary, however, based on the feedstock, the season, the region where the composting 

operation is being conducted, the tendency of the materials to compact, and the turning 

equipment used2

. Thus, windrows with leaves and tree trimmings tend to have larger pile 

dimensions than windrows of grass clippings with leaves. Windrow widths are generally 

twice the height of the pile. 

4. Once windrows are formed, the active composting begins. Active composting is 

characterized by high temperature, high level of oxygen demand and high evaporation 

rates due to temperature. There are several factors that need to be controlled to optimize 

rapid, efficient microbial decomposition of greenwaste. 

a. Temperature. During the active composting, thermophiles play a dominant role in 

decomposing organic materials, which results in heating within the windrow. When 

the internal windrow temperatures exceed above 150 degrees Fahrenheit, most 

thermophiles will die and the rate of decomposition decreases. Thus, it is necessary 

to maintain temperatures between 110 and 150 degrees Fahrenheit for microbial 

activities by turning the windrows to remove excess heat. Maintaining temperatures 

between 120 and 140 degrees Fahrenheit is generally preferred. According to 

literature 2, 8, 9, the interior of composting windrows should be maintained at 131 

SCAQMD I-2 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

degrees Fahrenheit for at least three days for pathogen destruction and to kill weed 

seeds. The California Integrated Waste Management Board (CIWMB) Regulations 

Title 14, Division 7, Chapter 3.1, Section 17868.3 (Pathogen Reduction) requires 

temperatures during active composting to be maintained at 131 degrees Fahrenheit or 

higher for 15 consecutive days for pathogen reduction. 

b. Nutrients. The balance of the nutrients should be properly maintained for optimum 

composting. Too much grass clippings (i.e., high nitrogen content) tend to cause an 

anaerobic composting condition because of its high demand for oxygen, which results 

in greatly reducing the composting rate. The excess nitrogen may evolve as ammonia 

gas, leading to odor problems and loss of nitrogen in the compost. As a result, the 

internal windrow temperatures do not rise high enough, composting slows down, and 

uncompleted compost can be produced. If there are too little grass clippings but 

much woody materials (i.e., high carbon content), the composting process also slows 

down due to lack of adequate nitrogen. Therefore, it is necessary to balance the 

carbon and nitrogen. A carbon to nitrogen (C:N) ratio ranging from 25:1 to 40:1 is 

reasonable for initial conditions, with a recommended C:N ratio of 30:1 for active 

composting1, 3, 5, 9, 11. C:N ratio decreases as decomposition proceeds and the ratio in 

the finished compost is below 20:1. 

Table I-1 lists some materials commonly used in making compost. A mix of one part 

grass to three parts leaves by volume is generally recommended for rapid composting. A 

volumetric ratio of one part wood chip: two parts leaves: one part grass is also good. 

Table I-1. Commonly Used Raw Compost Materials1, 8, 10-14

Material Characteristic C:N Ratio 

Bulking Agents 

- Wood Chips • Low Moisture 700:1

- Sawdust • High Porosity 500:1

- Wheat Straw • Low Nitrogen 100-150:1

- Corn Stalks 60:1

- Leaves (Dry), Grass Hay 80:1

Energy Materials 

- Grass Clippings • High Moisture 12-20:1

- Fresh Dairy, Chicken Manure • Low Porosity 15-18:1

- Garden Trimmings • High Nitrogen 19:1

Balanced Raw Materials 

- Ground Tree and Shrub Trimmings • Low to Medium Moisture 16-53:1

- Horse Manure and Bedding • Medium Porosity 25-50:1

- Deciduous Leaves • Medium Nitrogen 40:1

- Legume Hay 25:1

c. Oxygen. The feedstock should be maintained with a reasonable oxygen concentration 

for optimized microbial decomposition. Volatile organic compounds (VOCs) and 

ammonia (NH3) are produced during the anaerobic decomposition of greenwaste. To 

SCAQMD I-3 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

maintain aerobic composting conditions, windrows are turned with a front-end loader 

or a Scarab. The frequency of turning is determined by the windrow size, feedstock 

composition, stage of decomposition and moisture content, and is adjusted so aerobic 

conditions are maintained, not providing too much aeration, which can dry out the 

pile and impede composting. The suggested range of oxygen content is generally 

above 5 percent. 

d. Acidity/Alkalinity. It is common for the pH of the feedstock materials to become 

slightly acidic (i.e., down to 5.0) during the early stage of composting due to organic 

acid formation. The pH then begins to rise to near neutral conditions (6.5–8.0), and 

the composting process is relatively insensitive to pH within this range. If the pH 

reaches 9, nitrogen is converted to ammonia and becomes unavailable to organisms, 

resulting in a decomposition process that is too slow. 

e. Moisture. According to several composting manuals2-7, 9, 40–60 percent of moisture 

content is reasonable for the optimum composting conditions throughout the process. 

If the moisture level drops below about 40%, the nutrients are no longer in an 

aqueous medium and are not easily available to the microorganisms. Their microbial 

activity then decreases, and the composting process slows. For very dry leaves, 20 

gallons of water is required for each cubic yard of leaves. At a moisture level greater 

than 60 percent, porosity of the windrow decreases and air movement through void 

spaces will be impeded, which results in anaerobic conditions. 

f. Material Size. Since decomposition occurs on material surfaces, degradability can be 

improved by reducing the material size (which increases surface area) as long as 

porosity is not a problem. Good results are usually obtained when the material sizes 

range from 0.5 inch to 2.0 inches on average diameter. 

5. The windrows are turned as frequently as required responding to the conditions within 

the composting windrows, and water is added when needed. Infrequent and prescheduled turning can develop odor problems. Internal windrow temperatures should be 

monitored daily, and windrows need to be turned when temperatures reach a 

predetermined point. Turning the piles increases the rate of decomposition by mixing 

materials and exposing new surface areas. The active composting phase should last at 

least 22 days. Completely processing greenwaste with frequent turning may take two to 

four months. Based on the District staff report for Rule 1133.29

, 80 percent of VOC and 

50 percent of NH3 emissions are released during the 22-day active composting phase. 

6. Once the greenwaste has been composted, curing should take place and the windrow no 

longer heats when being turned. During the curing stage, compost is stabilized as the 

remaining available nutrients are metabolized by the microorganisms that are still 

present, and the need for oxygen and the evaporation rates decrease. While the curing 

stage may take another several weeks, it should last at least 40 days during which 20 

percent of VOC and 50 percent of NH3 emissions are released9

. 

SCAQMD I-4 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Postprocessing Stage 

7. Compost may be analyzed to ensure the stabilization is complete. Compost also can be 

tested for chemical or pathogen contamination and tested to determine nutrient levels, 

cleansed of unwanted materials, sorted by size, size-reduced, blended with other 

materials, stored, and/or bagged. 

Table I-2 summarizes troubleshooting and management guide for greenwaste composting. 

Table I-2. Troubleshooting and Management Guide for Composting Conditions6

Condition Possible reason Other clues Remedy 

Windrow fails to heat Materials too dry 

Materials too wet 

Not enough nitrogen 

Poor structure 

Cold weather and small pile 

size 

pH excessively low 

Cannot squeeze water from 

material 

Moisture content greater than 

60% 

C:N ratio greater than 50:1 

Pile settles quickly 

Windrow height less than 

3.5 feet 

pH less than 5.5 

Add water 

Add dry amendment 

or remix 

Add high-nitrogen 

ingredients 

Add bulking agent 

Enlarge or combine 

windrows; add 

highly degradable 

ingredients 

Add lime or wood 

ash and remix 

Temperature falls 

consistently over several 

days 

Low oxygen 

Low moisture 

Temperature declines gradually 

Cannot squeeze water from 

material 

Turn windrow 

Add water 

Uneven temperatures or 

varying odors in windrow 

Poorly mixed materials 

Uneven airflow 

Materials at different stages 

of maturity 

Visible differences in the pile 

moisture 

Visible differences in the pile 

moisture 

Temperature varies along the 

pile length 

Turn or remix 

windrow 

Remix windrow 

None required 

Pile does not reheat after 

turning 

Composting nearing 

completion 

Low moisture 

Approaching expected 

composting time period; 

adequate moisture level; 

C:N ratio less than 20:1 

Cannot squeeze water from 

materials 

None required 

Add water and remix 

SCAQMD I-5 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Table I-2. Troubleshooting and Management Guide (continued) 

Condition Possible reason Other clues Remedy 

Pile overheating 

(temperature greater than 

150 oF) 

Insufficient aeration for 

heat removal 

Moderate to low moisture 

Pile is too large 

Pile is moist 

Pile feels damp 

Height great than 8 feet 

Turn pile 

Add water 

Decrease the pile size 

Extremely high 

temperature (greater than 

170 oF in pile) 

Spontaneous combustion Low moisture content; pile 

interior looks or smells charred 

Decrease pile size; 

maintain proper 

moisture content; add 

water to charred 

sections; break down 

pile, combine with 

other piles 

High temperature or 

odors in curing or storage 

pile 

Compost is not stable 

Piles are too large 

Short active composting period; 

temperature and odor change 

after mixing 

Height greater than 8 feet; 

width greater than 20 feet 

Manage pile for 

temperature and odor 

control; turn piles as 

needed; limit pile 

size 

Decrease pile size 

Ammonia odor coming 

from composting piles 

High nitrogen level 

High pH 

Slowly available carbon 

source 

C:N ratio less than 20:1 

pH greater than 8.0 

Large woody particles; C:N 

ratio less than 30:1 

Add high carbon 

amendments 

Avoid alkaline 

ingredients 

Increase the carbon 

proportion 

Odors generated only 

after turning 

Odorous raw materials 

Insufficient aeration; 

anaerobic interior 

High temperatures 

Falling temperatures 

Frequent turnings; 

increase porosity; 

add odor-adsorbing 

amendment 

Shorten time interval 

between turnings; 

increase porosity 

Foul odor coming from 

composting piles 

continually 

Anaerobic conditions 

 Materials too wet 

 Poor structure 

 Pile compacted 

 

 

Insufficient aeration 

Anaerobic conditions 

 Pile too large 

 Airflow uneven or short 

 circuiting 

Low temperature 

High temperature 

Add dry amendments 

Add bulking agent 

Remix pile and add 

bulking agent if 

necessary 

Turn pile more 

frequently 

Decrease the pile size 

Remix pile; change 

recipe 

SCAQMD I-6 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Table I-2. Troubleshooting and Management Guide (continued) 

Condition Possible reason Other clues Remedy 

Fly or mosquito problems Flies breeding on compost 

piles 

Flies breeding in raw 

materials 

Mosquito breeding in 

stagnant water 

Flies hover around piles 

Wet raw materials stored on 

site more than 4 days 

Standing puddles of water 

Turn piles every 4 to 

7 days 

Handle raw materials 

promptly 

Grade site properly 

Compost contains clumps 

of materials and large 

particles; texture is not 

uniform 

Poor mixing of materials or 

insufficient turning 

Airflow uneven 

Raw materials contain large 

particles and nondegradable or slowly 

degradable materials 

Active composting not 

complete 

Original raw materials 

discernible in compost 

Wet clumps of compost 

Large, often woody, particles in 

compost 

Curing piles heat or develop 

odors 

Screen compost; 

improve initial 

mixing 

Screen or shred 

compost 

Screen compost; 

grind and/or sort raw 

materials 

Lengthen composting 

time or improve 

composting 

conditions 

Summary 

Greenwaste composting is defined by an aerobic decomposition of green material by 

microorganisms. Temperature, moisture content, and oxygen level are key parameters that need 

to be controlled throughout the composting process to prevent anaerobic decomposition, which 

may result in emissions of NH3 and VOCs that play an important role in forming secondary 

particulate matter and ozone in the atmosphere. 

SCAQMD I-7 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

SCAQMD I-8 July 2011 

References 

1. Evanylo, G.K. et al. The Virginia Yard-Waste Management Manual. Virginia Polytechnic 

Institute and State University Virginia Cooperative Extension. 2003. 

2. United States Environmental Protection Agency. Composting Yard Trimmings and 

Municipal Solid Waste. 1994. 

3. Alberta Environment. Leaf and Yard Waste Composting Manual. 1999. 

4. Alberta Environment. Mid-Scale Composting Manual. 1999. 

5. Forgie, D.J.L., Sasser, L.W., and Neger, M.K. Compost Facility Requirements Guideline: 

How to Comply with Part 5 of the Organic Matter Recycling Regulation. British Columbia. 

2004. 

6. Rynk, R. et al. On-Farm Composting Handbook. Northeast Regional Agricultural 

Engineering Service Cooperative Extension. 1992. 

7. Gannet Fleming. Municipal Yard Waste Composting Facility Operator’s Reference Guide 

and Handbook. Borough of Philipsburg, Centre County, Pennsylvania. 2001. 

8. DSM. Yard Waste Composting: Operator Training Manual. DSM Environmental Services, 

Inc. 2004. 

9. SCAQMD. Final Staff Report for Proposed Rules 1133, 1133.1, and 1133.2. South Coast Air 

Quality Management District. 2003. 

10. Cogger, C.G. and Sullivan, D.M. Backyard Composting. Washington State University 

Cooperative Extension. 2001. 

11. Schneider, R.M. et al. Kentucky Composting Manual. Kentucky Department of 

Environmental Protection Division of Waste Management. 2001. 

12. Washington State Department of Ecology. On-Farm Composting of Livestock Mortalities. 

2005. 

13. Christian, A.H., Evanylo, G.K., and Pease, J.W. On-Farm Composting: A Guide to 

Principles, Planning and Operations. Virginia Polytechnic Institute and State University 

Virginia Cooperative Extension. 1997. 

14. Canadian Organic Growers. Organic Field Crop Handbook. 2001. 
PAR 1133.1 and PR 1133.3 Final Staff Report 

APPENDIX II – EMISSION CONTROL TECHNOLOGY 

This section summarizes advanced emission control technologies that are associated with 

requirements of PR 1133.3. Advanced emission control technologies are engineered control 

methods that include a covered aerated static pile (ASP) composting system. These systems are 

commercially available and can be deployed by vendors. Brief descriptions of each system are 

given below. Inclusion of these vendors in this report does not imply or serve as an endorsement 

of any vendor or product by the District. 

Negative ASP System with Emission Controls 

One of the covered ASP systems is the AC ComposterTM and CompDogTM (pipe-less aeration 

system)1

, a covered negative-pressure ASP with biofilter provided by Engineered Compost 

Systems (ECS). A brief operational principle of this system follows. Once the feedstock mix is 

ready for placement in a windrow, an inflatable tube is laid down where middle of the pile will 

be located. The mixed feedstock is then placed over the tube using a wheeled front-end loader, 

allowed to settle around the tube for 12 to 24 hours, and covered with a waterproof tarp 

following the insertion of monitoring probes. The probes are linked to a computer to monitor 

temperature and do not have moisture sensors on them. The computer is capable of adjusting the 

air pressure to maintain proper aerobic composting conditions. After the compost settles, the 

inflatable tube is deflated and removed from the pile, creating a ventilation tunnel through the 

pile. The tunnel is then closed at one end by filling it with feedstock from the pile and a 

ventilation pipe is inserted into the other end. The pipe is connected to a blower that produces a 

negative air pressure, pulling air into the pile from the outside through small holes in the tarp. 

As air is being drawn through the piles, it is sent to a biofilter composed of moist wood chips and 

compost. Pulled air is mixed with ambient air to reduce the temperature of the exhaust air. As 

the air rises through the biofilter, it removes contaminants and odors through microbial action 

prior to releasing back to the atmosphere. Figure II-1 shows an enclosed negative ASP with 

biofilter composting system. 

Figure II-1. Covered Negative-pressure ASP with Biofilter System 

While the active composting process has three phases of approximately two-week period, the 

duration of each phase could be flexible. The first pile will compost for two weeks. At that end, 

SCAQMD II-1 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

the tarp is removed and the pile is turned using a wheeled front-end loader into a new zone. 

Once the first pile is moved to the second zone, the tarp and probes are placed again. This action 

occurs every two weeks over a six-week period. When the composting process is completed at 

the end of the sixth week, the finished compost may be relocated to a designated area for curing, 

as appropriate, for an additional four to eight weeks. All phases are covered and aerated, and the 

exhaust air is vented to the biofilter. 

Positive ASP System without Biofilter 

The other type of covered ASP systems is the covered positive-pressure ASP using a triple layer 

membrane compost cover. Since this type of technology pushes air into the pile, it does not need 

a biofilter. One kind of this covered, positive-pressure ASP technology is W.L. GORE & 

Associates’ GORE® Cover composting system2

. The GORE® Cover utilizes composting with 

forced aeration coupled with a semi permeable membrane cover over the compostable pile. The 

piles are the same size in each of the three Phases. GORE® Covers are used only in Phase I and 

II and are optional for Phase III. Each pile may have a concrete head wall to retain the material 

in each pile on the compost pad. Two aeration trenches are under each pile. These trenches 

serve as ducts to provide air to the pile and also to collect leachate coming from the pile. Each 

pile has a blower to provide air to the composting material via the aeration trenches. The 

trenches are cast in concrete to provide a solid impervious surface. The entire compost pad 

consists of a concrete slab or asphalt, which allows for the collection and separation of all storm 

water and leachate. 

The total composting process takes approximately eight (8) weeks. The compost pad is divided 

into three sections: Phase I (high rate composting), Phase II (maturation) and Phase III 

(finishing). Material remains in the Phase I section for 4 weeks, followed by 2 weeks in the 

Phase II section and 2 weeks in the Phase III section. As the composting process proceeds, the 

volume of material and mass of material is reduced through composting losses. 

After a pile is built, the GORE® Cover is placed over the entire pile. A mobile winding machine 

for installation and removal of the cover is available. Once the cover is installed and secured in 

place, a weighting system (sand or water filled pipes) are placed at the edge of the cover and 

fixed in position to make an enclosed system. Stainless steel temperature and oxygen probes are 

installed through the cover into the composting material. The blowers are controlled by a 

Programmable Logic Controller (PLC) to optimize the composting process using readings from 

temperature and oxygen sensors under the cover. All data is collected in real time for monitoring 

and reporting purposes. Figure II-2 shows the general configuration of the GORE® Cover 

compost system. 

The GORE® Cover membrane is laminated between two polyester layers that selectively 

influence the treatment process. The membrane laminate technology protects the compostable 

material from the penetration of rainwater and yet allows naturally occurring carbon dioxide 

produced during the composting process to escape. In addition, a fine film of condensation 

develops on the inside of the tarp covers during the composting process, suppressing odors and 

other gaseous emissions. These gases are partly dissolved in the film of water and drop back into 

the compostable material where they continue to be broken down by beneficial bacteria. The 

micro-porous structure of the GORE® Cover prevents the final product from being too wet, yet 

SCAQMD II-2 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

at the same time ensures that there is sufficient moisture retained to allow the material to be 

decomposed. 

Figure II-2. GORE® Cover System Configuration 

Another kind of this covered, positive-pressure ASP technologies is Managed Organic Recycling 

(MOR) composting cover system3. The MOR compost cover keeps odor, heat, microorganisms 

and some moisture contained, while releasing oxygen, bits of carbon monoxide and some 

moisture. This complex cover material allows the covered piles to be controlled with a blower 

fan, connected to a ventilated air hose snaking beneath the pile. The fan is necessary since the 

pile should never be cooler than 110 or warmer than 160 degrees Fahrenheit. The MOR compost 

cover allows airflow to be decreased if the pile is not hot enough or increased if the pile begins 

getting too warm. This is done by adjusting the fan output using a torque timer. A torque timer 

can be set so the fan blows air throughout the pile every ten minutes and then stays off for ten 

minutes before turning on again. The timer can be adjusted to the setting that works best for the 

pile. The pile size, ingredients used, weather and life of the pile will dictate the most suitable 

settings for a specific pile. Figure II-3 presents an example of MOR compost cover system. 

SCAQMD II-3 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Figure II-3. Covered Positive-pressurized MOR Compost Cover 

References 

1. Engineered Compost Systems (ECS), www.compostsystems.com/ac_composter.html, 

accessed in 2010. 

2. GORE® Cover, www.gore.com/en_xx/products/fabrics/swt/index.html, accessed in 2010. 

3. Managed Organic Recycling, Inc., www.morcompost.com, accessed in 2010. 

SCAQMD II-4 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

APPENDIX III – EMISSION REDUCTIONS AND COST EFFECTIVENESS 

Emission Factors 

Baseline emission factors were developed based on the emissions source tests conducted by the 

SCAQMD, the state and other air districts from 2001 to 2009 for greenwaste composting 

windrows. The following emissions test results were used in developing the baseline emission 

factors. 

Table III-1. Emission Tests Used to Develop the Baseline Emission Factors 

Test facility Location Season 

samples taken 

Test 

year 

Jurisdiction 

Inland Empire Composting Facility Colton Fall 2001 SCAQMD 

Inland Empire Composting Facility Colton Winter 2001 SCAQMD 

Jepson Prairie Organics (JPO) 

Compost Facility 

Vacaville Summer 2005 Yolo-Solano (YS) 

AQMD 

Modesto Compost Facility Modesto Fall 2006 CIWMB 

Site X Central Valley Spring 2008 SJVAPCD 

Zamora Compost Facility Zamora Spring 2009 YSAQMD 

Staff reviewed the emissions source test results in Table III-1, and recommended as many of the 

emissions test results as possible to be included in developing the baseline composting emission 

factors that represent the types of composting that takes place in the South Coast jurisdiction. 

Prior District emission factors included emissions from stockpiles, static piles and windrow 

composting combined. For PR 1133.3, VOC and ammonia emissions only from static pile and 

windrow composting operations were considered in developing baseline emission factors to 

calculate the emissions inventory. Static pile composting is a composting technique that is 

characterized by the absence of turning. The material is placed into piles where it decomposes 

over an extended period of time with no or little mixing. Oxygen supply is passive; warm air 

leaving the pile at the top is replaced by air entering from the outside of the pile at the bottom. 

Composting is slow in static piles, and is often used to kill weed seeds prior to a land application, 

such as spreading on agricultural land. 

Table III-2 shows windrow composting emission factors calculated from various emissions test 

data. Two Inland (SCAQMD) tests data were measured over the static and windrow phase 

compost piles, and other test data were measured over the active and curing phase compost piles. 

Note that there are differences between the Inland data and other air districts’ data. The 

District’s Inland tests data can be considered as a snap shot of emissions because the calculation 

is based on tests conducted on specific days of the composting period. Other air districts’ test 

data were also measured on specific days during a full composting cycle and then total 

cumulative emissions were calculated for the full cycle period (days not sampled were 

interpolated). The Inland data has been included as it is relevant local data. Using daily 

composting throughput, emission factors were weighted to calculate composite emission factors. 

SCAQMD III-1 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Table III-2. Composting Emission Factors 

Site Sampling age of 

material 

Season samples 

taken 

Throughput 

(tons/day) 

VOC 

(lbs/wet ton) 

Ammonia 

(lbs/wet ton) 

Inland Over the static and 

windrow phase 

Winter 307 1.56 0.26 

Inland Fall 350 2.25 0.63 

Modesto Over the active and 

curing phase (days 

not sampled were 

interpolated) 

Fall 103 0.85 Not Available 

Site X Spring 200 6.30 2.34 

JPO Summer 163 5.65 0.24 

Zamora Spring 319 10.03 0.445 

Weighted average emission factors 4.67 0.66 

VOC emissions profiles were examined for greenwaste emission source tests conducted at 

Modesto, Zamora and JPO greenwaste compost facilities. Emission source tests have shown that 

a vast majority (~90 percent) of VOC emissions are produced during the first 22 days of 

greenwaste composting (i.e., active phase) and about 70 percent of ammonia emissions emanate 

from the active phase period of greenwaste composting. VOC emissions tend to increase 

immediately after greenwaste is chipped or ground, typically with peaks during three to seven 

days, and then decrease sharply over time. Such emissions profiles are shown in Figures III-1 

and III-2. Based on the cumulative emissions of VOC and ammonia during the active phase, it is 

assumed that VOC emissions during the active composting phase account for 91 percent of total 

cumulative emissions and ammonia emissions account for 70 percent of total cumulative 

emissions, respectively. Overall, the District’s proposed greenwaste composting operations 

emission factors are shown in Table III-3. For PR 1133.3, the total composting emission factors 

during the active and curing phase were used to refine the baseline (uncontrolled) emissions 

inventory. However, emission reductions and cost effectiveness were calculated using the active 

phase emission factors only, since the proposed mitigation measures are required only for the 

first 15 days of the active phase period of composting. 

SCAQMD III-2 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Figure III-1. VOC Emissions Profile for Greenwaste Composting. 

SCAQMD III-3 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Figure III-2. Ammonia Emissions Profile for Greenwaste Composting. 

Table III-3. Greenwaste Composting Baseline Emission Factors (EF) 

Windrow composting EF (lbs/wet ton) Total composting EF 

Active phase Curing phase (lbs/wet ton) 

VOC 4.25 0.42 4.67 

Ammonia 0.46 0.20 0.66 

Emissions Inventory 

Emissions can occur during chipping and grinding activities, stockpiling of chipped or ground 

greenwaste, and composting of chipped or ground greenwaste. Emissions during chipping and 

grinding have not been quantified as no data are available. Emissions during stockpiling are 

quantifiable, but are not quantified for the purpose of this rulemaking. PR 1133.3 requires 

removing the material from the site within 48 hours of receipt or up to seven days maximum, 

with approval from the LEA, which is consistent with the Title 14 requirement. Staff determined 

that there would be no emission reductions from stockpiling operations because the proposed 

SCAQMD III-4 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

holding time requirement has already been established in the state regulation. Composting 

emissions of chipped or ground greenwaste at facilities solely subject to PR 1133.3 are 

quantifiable using composting throughput and the composite emission factors estimated in the 

previous section. 

Initially 15 facilities were identified from a survey for greenwaste composting industry staff 

conducted in 2007 in the South Coast region. Operational status has been updated for 2009–

2010. Two facilities were found to be out of business and four facilities were added. Seventeen 

facilities have been identified as subject to PR 1133.3. Baseline emissions inventory was 

developed using the baseline emission factors (i.e., total composting EF in Table III-3) and 

actual throughput of greenwaste processed for composting operations for these 17 facilities. 

Table III-4 shows the baseline emissions inventory profile for these facilities. 

As a whole, based on 365 days per year, the greenwaste composting operations produce 

approximately 2.66 tons of VOC emissions per day and 0.38 tons of ammonia emissions per day. 

Table III-4. Greenwaste Composting Baseline Emissions Inventory 

Total 

throughput 

(tons/year)

Composting emission factor 

(lbs/wet ton) 

Baseline composting emissions 

(tons/year) 

VOC Ammonia VOC Ammonia 

416,300 4.67 0.66 972 137 

Total emissions in tons per day 2.66 0.38 

Among the existing 17 greenwaste composting facilities, 12 facilities produce annual VOC 

emissions from windrow composting operations exceeding the ten tons per year potential-to-emit 

threshold for major sources as defined in District Rule 3001 relative to Clean Air Act, Title V, 

requirements. However, as windrow composting is not permitted and emissions are fugitive in 

nature, Title V does not apply in this case. The largest greenwaste composting facility is 

estimated to emit ~450 tons of VOC per year from windrow composting operations. 

Emission Reductions 

PR 1133.3 would require mitigation measures, such as finished compost cover and water 

irrigation during the first 15 days of the active phase composting. The SJVAPCD contracted 

with San Diego State University for a study investigating mitigation measures for compost 

emissions reduction. The San Diego State University team conducted tests at the Tulare 

Composting and Biomass Facility in Tulare, CA. Mitigation measures tested included water 

irrigation and finished compost cover. Water irrigation was tested on an active phase 

composting windrow and showed 24 percent reductions in VOC emissions during the 22 days 

active phase composting period. Another greenwaste pile was tested with finished compost 

cover. Finished compost was applied to the pile such that the top is six inches thick, after initial 

pile formation and after each turning during the active phase composting, and showed 53 percent 

reductions in VOC emissions. In an earlier Modesto compost study, about 75 percent VOC 

reductions were achieved with six inches of finished compost cover. However, unlike the Tulare 

mitigation measure study in which the finished compost cover was applied repeatedly after 

turning during the 22 days active phase composting, finished compost cover was applied after 

SCAQMD III-5 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

the initial pile formation and after the first turning only for the first 14 days of the active phase 

composting in the Modesto study. Therefore, District staff concluded that the SJVAPCD’s test 

results of control efficiency (i.e., 53 percent) would be more reflective of the control over the 

active phase composting period involving multiple turnings. 

PR 1133.3 would require the operator to apply finished compost cover to the peak of the pile so 

that the top is six inches thick during the first seven days after initial pile is formed, and then to 

apply water to the top half of the pile so that the top three inches of the pile is wet during the 

following eight days, which constitutes a total of the first 15 days of the active phase of 

composting. VOC emissions during the first 15 days of the active phase composting accounted 

for the majority (~87 percent) of total VOC emissions from composting. Weighted average 

control efficiency was calculated by multiplying cumulative emissions and control efficiencies of 

mitigation measures, as shown in Table III-5. The three different VOC emissions profiles shown 

in Figure III-1 and the two different ammonia emissions profiles shown in Figure III-2 were used 

in calculating the weighted average control efficiency. 

Table III-5. Weighted Average Control Efficiency for VOC and Ammonia 

Active phase VOC emissions rate (%) Control efficiency 

composting Modesto Zamora JPO Average Mitigation measures Composite - VOC

First 7 days 61 59 89 70 53% - compost cover 41%* Following 8 days 24 24 4 17 24% - watering 

15 days total 85 83 93 87 

* Compost cover for the first 3 days and watering for the following 12 days yield 31% efficiency. 

Active phase Ammonia emissions rate (%) Control efficiency 

composting Modesto Zamora JPO Average Mitigation measures Composite - NH3

First 7 days N/A 36 26 31 53% - compost cover 23%^

Following 8 days N/A 28 28 28 24% - watering 

15 days total N/A 64 54 59 ^

 Compost cover for the first 3 days and watering for the following 12 days yield 17% efficiency. 

Staff obtained site-specific information about the pathogen reduction process from greenwaste 

composting facilities. About half of the composting throughput begins the pathogen reduction 

process immediately after the initial pile is formed. Composite control efficiency for VOC and 

ammonia was calculated to be 31 and 17 percent, respectively. The site-specific control 

efficiency data were also used in calculating emission reductions that are shown in Table III-6. 

In summary, the following facts and assumptions were made to calculate emission reductions: 

1. The existing facilities have open composting pile or windrow operations which have no 

emissions control device; 

2. The VOC emissions factor for the active phase of the composting process is 4.25 lbs/ton 

of greenwaste throughput; 

3. The VOC emissions factor for the curing phase of the composting process is 0.42 lbs/ton 

of greenwaste throughput; 

4. The ammonia emission factor for the active phase of the composting process is 0.46 

lbs/ton of greenwaste throughput; 

SCAQMD III-6 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

5. The ammonia emission factor for the curing phase of the composting process is 0.20 

lbs/ton of greenwaste throughput; 

6. The VOC emissions during the first seven days of the active phase period of composting 

process account for 70 percent of total cumulative emissions during the full composting 

cycle; 

7. The VOC emissions during the following eight days of the active phase period account 

for 17 percent of total cumulative emissions during the full composting cycle; 

8. The ammonia emissions during the first seven days of the active phase period of 

composting process account for 31 percent of total cumulative emissions during the full 

composting cycle; 

9. The ammonia emissions during the following eight days of the active phase period 

account for 28 percent of total cumulative emissions during the full composting cycle; 

10. The control efficiency of finished compost cover applied to the top of the active phase 

compost pile is 53 percent for VOC emissions based on the SJVAPCD’s mitigation 

measure study; 

11. The control efficiency of water irrigation on the active phase compost pile is 24 percent 

for VOC emissions, based on the SJVAPCD’s mitigation measure study; and 

12. The same control efficiencies of 24 percent with water irrigation and 53 percent with 

finished compost cover as for VOC emissions can be applied for ammonia emissions. 

With regard to Assumption #12, the control efficiency with water irrigation and finished compost 

cover was not evaluated for ammonia in the original mitigation measures study. However, 

historically, District biofilter emissions test results have shown greater controls in ammonia 

emissions than VOC emissions. Finished compost is used as an element of biofilter media. 

Conservatively, finished compost cover was assumed to have the same 53 percent control for 

ammonia as was shown for VOCs. The 24 percent control with water irrigation was achieved 

with multiple water irrigation. Considering ammonia is a highly water-soluble gas, it was 

conservatively assumed that the water irrigation had the equivalent control efficiency for 

ammonia. 

Staff calculated reductions based on 53 and 24 percent control efficiencies with the proposed 

applications in PR 1133.3. Emission reductions (ER) are calculated by multiplying baseline 

(uncontrolled) emissions by an overall control efficiency using the following equation. 

Uncontrolled emissions are calculated by multiplying the amount of composting throughout by 

an emission factor (EF). 

, 

where EF is an emission factor for VOC or ammonia and control efficiency is an overall 

composite control efficiency. Since PR 1133.3 requires that the finished compost cover and 

watering are applied only for the first 15 days of the active phase period of composting process, 

the reductions during the curing phase of composting are considered to be zero. 

Table III-6 presents that with the implementation of PR 1133.3, 0.9 tons of VOC and 0.1 tons of 

ammonia are anticipated to be reduced per day from the existing 17 greenwaste composting 

facility operations. 

SCAQMD III-7 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Table III-6. Greenwaste Composting Emission Reductions 

Mitigation measures 

(Active phase only) 

Throughput 

(tons/year) 

Number 

of 

facilities 

Baseline emissions 

(tons/day) 

Composite control 

efficiency (%) 

Emission reductions 

(tons/day) 

VOC Ammonia VOC Ammonia VOC Ammonia 

Finished compost 

cover and water1

 208,300 16 1.33 0.19 41% 23% 0.50 0.03 

Finished compost 

cover and water2 208,000 1 1.33 0.19 31% 17% 0.38 0.02 

Total 416,300 17 2.66 0.38 0.88 0.05 

1

 7 day retention prior to turning. 

2

 3 day retention prior to turning for pathogen reduction. 

Compliance Costs

Compliance costs of PR 1133.3 were estimated based on the proposed requirements of the rule. 

Under PR 1133.3, the operator of any greenwaste composting operation would be required to 

hold greenwaste materials as allowed by the LEA. This requirement is to harmonize the holding 

time requirement of the state regulation. Since the removal requirement has already been 

established in the state regulation, there would be no compliance costs incurred with this material 

holding time requirement of PR 1133.3. 

Compliance costs consist of one-time purchase costs of equipment and annual operation and 

maintenance (O&M) costs involving water irrigation and finished compost cover. PR 1133.3 

requires only one time application of finished compost cover after an initial compost pile is 

formed. This can be done by existing equipment, such as a front-end loader or a skit loader, at 

the facility. Since facilities are assumed to already have turning machines for their composting 

operations, such as a wheeled front-end loader, additional purchase of such equipment is 

unnecessary and thus this equipment costs were excluded from this estimation. Therefore, 

compliance costs only involve annual operational costs for water irrigation and finished compost 

cover. For the worst case, it was assumed that water is applied five times to the compost pile. 

Annual O&M costs would be incurred with the following proposed requirements: 

• Six inches of finished compost cover to the top of the active phase compost piles; and 

• Three inches watering to the top half of the active phase compost piles. 

To estimate the annual O&M costs for each facility, the following assumptions were made: 

1. Compost pile: 

a. Is trapezoidal in shape 

b. Is 16 feet wide, 7 feet high and 200 feet long 

c. Has four cubic yards per ton pile density 

2. The unit cost of the potable water irrigation is assumed to be $0.40 per ton of throughput 

and the unit cost of the reclaimed water irrigation is assumed to be $0.29 per ton of 

throughput with the following assumptions; 

a. Water use: 

SCAQMD III-8 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

i. Pile management at 50 percent moisture content corresponds to 45 percent 

average free air space 

ii. Wet piles assumed to be 75 percent moisture content, which corresponds 

to 23 percent average free air space, therefore the change in free air space 

of 22 percent 

iii. Amount of water applied for the worst case day to fill the free air space for 

a 3 inches pile depth corresponds to 19 gallons of water per ton throughput 

iv. Total volume of annual water use for 5 times watering is approximately 37 

million gallons for 17 existing greenwaste composting facilities 

b. Potable water for non-residential/landscape purposes at a rate of $793 per acrefoot water (reclaimed water for irrigation is at a rate of $427 per acre-foot water) 

c. 20 minutes are taken to irrigate 100 tons of windrow 

d. Five turning events during the active phase 

e. $10 per hour labor rate for irrigation to a depth of three inches 

3. The unit cost of the finished compost cover application is assumed to be $0.79 per ton of 

throughput from the Modesto/Bakersfield study with the following assumptions; 

a. 15 minutes application time per 110 feet length of windrow 

b. $180 per hour for equipment and operator with 50 percent overhead 

c. One time application during the active phase 

d. Four cubic yards per ton density 

Staff calculated the potential water use associated with the requirement for water application to 

windrows before turning. Using the Science of Composting (E. Epstein, CRC Press, 1997), staff 

was able to derive the free air space in a composting pile relative to moisture content. Based on 

the data provided in the reference, staff identified that average composting moisture content of 

50% has an average free air space of 45%. Under PR 1133.3, the piles are to have water applied 

to make the piles “wet” before turning. Based on comments received, “wet” material would 

have a moisture content of about 75%. According to the reference, this moisture content would 

have a free space of 23%. Assuming the material itself is saturated, the amount of water to be 

applied to make the material “wet” is represented by the difference in the moisture content 

(22%), thereby filling the free air space. Using the prescribed compost pile parameters, the 

maximum amount of water to be used in one year is approximately 37 million gallons. Using 

site specific information obtained from the 17 affected facilities, the worst case one-day water 

use would be about 106,000 gallons, of which ~55,400 gallons is potable and ~50,900 gallons is 

reclaimed or untreated well or canal water. It should be noted that the facilities currently use 

more than 50 million gallons of water and the operations may very well be adjusting the 

application times to accommodate the rule requirements. For example, watering the piles before 

turning as opposed to after could be employed thereby minimize additional water use. It should 

also be pointed out that watering is only required to the extent the top 3 inches is wet, which may 

not require water application at all depending on the time of year and climatic conditions. 

Using the above assumptions and actual throughput, annual compliance costs are estimated as 

shown in Table III-7. Annual compliance cost and total annual cost are the costs averaged over 

all 17 affected facilities. Total annual compliance costs range from $700 per facility to $215,800 

per facility with a facility average of $29,000 per year. It should be noted that the compliance 

cost-to-throughput ratio for each affected facility is calculated to be up to $1.15 per ton of 

SCAQMD III-9 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

SCAQMD III-10 July 2011 

throughput for adding an initial finished compost cover and watering before each turning (based 

on weighted water source cost of $0.36 per ton and $0.79 per ton of throughput for adding one 

time finished compost cover). 

Table III-7. Compliance Cost Estimates and Proposed Rule Requirement 

Throughput 

 (tons/year) 

Number 

of 

facilities 

Annual compliance 

costs 

(Avg. $/year) 

Proposed rule requirement Total annual 

costs 

(Avg. $/year) 

416,300 17 $8,400 Finished compost cover $29,000 $20,600 Water irrigation 

Cost Effectiveness 

Cost effectiveness was calculated based on both VOC and ammonia combined emission 

reductions, and VOC-only emission reductions for windrow composting with finished compost 

cover followed by water irrigation. 

Table III-8 summarizes greenwaste composting average cost effectiveness for VOC-only and for 

VOC and ammonia combined. Average cost effectiveness was estimated to be about $1,340 for 

ton of VOC-only emissions reduced and about $1,270 for ton of VOC and ammonia combined 

emissions reduced. 

Table III-8. Greenwaste Composting Average Cost Effectiveness (C-E) 

Throughput 

(tons/year)

Mitigation 

measures 

(Active phase only)

Total annual costs 

(Avg. $/year)

Average C-E 

for VOC only 

($/ton)

Average C-E 

for VOC & Ammonia 

($/ton)

416,300 Finished compost cover 

and water combined $29,000 $1,340 $1,270 
PAR 1133.1 and PR 1133.3 Final Staff Report 

APPENDIX IV – PUBLIC COMMENTS AND RESPONSES 

This section summarizes comments received during the public comment period ending February 

23, 2011 associated with a Public Workshop and California Environmental Quality Act (CEQA) 

Scoping Session for Proposed Amended Rule (PAR) 1133.1 and Proposed Rule (PR) 1133.3 that 

was held on February 9, 2011. 15 comment letters were received, including U.S. EPA, CARB, 

and CalRecycle. These comments were reflected in the revised rule proposal for which another 

working group meeting was held on May 10, 2011, after which nine additional comment letters 

were received. Staff response to verbal and written comments, including e-mails, are 

summarized below by proposed rule subdivisions to which individual comments are related. 

Similar comments on the same rule element were integrated into one single comment. 

February 23rd Public Workshop Comments (January 25, 2011 version of the rules)

US EPA Comments 

Comment #1: We recommend the environmental impact analysis for the PR 1133.3 include 

consideration of: 1) groundwater impacts where sprinkler irrigation is used; and 

2) NOx and PM emissions that result from control measures. 

Response #1: Groundwater impacts and NOx and PM emissions by proposed control 

measures will be considered in the environmental impact analysis. The 

proposed rule would require mitigation measures using water irrigation and 

finished compost cover. Composting facilities already apply water to their 

compost piles to maintain moisture level and additional watering only applies to 

the first three inches of the pile depth before turning. Therefore, the impact of 

watering on the groundwater would be negligible. The finished compost cover 

would only be required one time after the initial pile is formed. According to 

staff analysis of diesel emissions, NOx and PM emissions, as well as water use 

from this rule implementation are under the CEQA daily threshold. 

Comment #2: Add a definition of the undefined term “finished compost.” 

Response #2: Definition of finished compost has been added. 

Comment #3: National policy discourages State Implementation Plan (SIP) provisions that 

allow AQMD discretion to independently modify SIP requirements (e.g., Clean 

Air Act Section 110(i), the Little Bluebook and 52 FR 45109, 11/24/87). EPA 

recommends that the discretion be further limited by specifying the procedures 

that will be used to verify compliance with this section or by specifying that 

alternative mitigation measures will be based on a test protocol that is approved 

AQMD, CARB “and” EPA. 

Response #3: Staff revised the rule language as recommended. 

Comment #4: PR 1133.1 requires maintaining records on-site for two years. To improve 

enforceability and greater consistency with Title V requirements, EPA 

recommends requiring that operators maintain these records for five years. 

SCAQMD IV-1 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Response #4: Staff revised rule language that the prior two year records should be maintained 

on-site and the remaining three year records would be available within one 

week of request (i.e., five years total). 

Comment #5: Please remove or better justify the 40-day limits in the definition of the curing 

phase of composting in PR 1133.3. California, for example, defines curing 

composting only by pathogen reduction, as described in California Code of 

Regulations (CCR) Section 17868.3, and after most of the readily metabolized 

material has been decomposed and stabilized. See CCR, Title 14, Section 

17852(a)(13). 

Response #5: Definitions of the 22-day active composting and 40-day curing have already 

been established in District Rule 1133.2. These limits were supported by 

information found in EPA 503 regulations and other studies found in the 

literature of the Technology Assessment Report for Proposed Rule 1133 (dated 

March 22, 2002). Specifically, the 22- and 40-day limits are based on the 

source test conducted for odor emissions. 

Comment #6: In paragraph (c)(9) of PR 1133.3, foodwaste mixed with greenwaste is 

considered foodwaste. This seems to conflict with the meaning of foodwaste in 

(d)(1) and (d)(2). For example, if any mixture of greenwaste and foodwaste is 

considered foodwaste as indicated in (c)(9), then theoretically, “10% foodwaste, 

by weight” in (d)(1) and/or (d)(2) could contain up to 99% greenwaste. It may 

be helpful to distinguish between foodwaste (as defined in this section) and 

waste from food material. 

Response #6: The definition of foodwaste has been modified. The sentence that “Foodwaste 

mixed with greenwaste is considered foodwaste.” has been deleted. 

Comment #7: Please consider clarifying the term “periodic basis.” Also, per California state 

law, it would appear that the minimum turns needed during the composting 

cycle is five. Please consider including this requirement in the rule. 

Response #7: The term “turned windrow” has been removed from this rule and thus 

clarification is not needed. This rule no longer requires a specific type of 

composting system as a minimum requirement. The five times turning in the 

CCR is relative to pathogen reduction and may occur any time during the active 

or curing phase. 

Comment #8: Please specify in the rule the specific temperature parameters that will be used. 

Response #8: Temperature measurement is no longer required in this proposed rule. Rather, 

reference is made to temperature monitoring per CCR, Title 14. 

Comment #9: Please clarify the basis of source testing every two years in lieu of more 

frequent testing that is required of many other sources. 

Response #9: Although the cost of source testing is not as expensive as commented from the 

public, considering those comments on the source testing frequency, staff 

revised the frequency from every two years to every three years. This would be 

consistent with existing permitting practice. 

SCAQMD IV-2 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Comment #10: Please clarify whether Attachment A of Rule 1133.2 is to be included in the 

State Implementation Plan (SIP). We believe it is appropriate to include this 

attachment in Rule 1133.3. 

Response #10: Attachment A of existing Rule 1133.2 has been previously approved into the 

SIP. However, this attachment has been modified specific to PR 1133.3 and is 

included within the rule. The attachment will be part of the SIP submittal. 

Comment #11: Please list the applicable dates of those TMECC test methods for PR 1133.3. 

Please clarify the number of replicate samples needed for these test methods. 

We recommend averaging the results of three samples. 

Response #11: The applicable dates of those TMECC test methods are listed as recommended 

in the revised rule language. Staff added the requirement of triplicate samples 

needed for the TMECC test methods. 

Comment #12: Please consider adding size thresholds to the exemptions of Rule 1133.3, 

specifically community composting. It may be appropriate to apply some or all 

of PR 1133.3 to facilities addressed here that are very large. 

Response #12: Staff added conditions to the exemption for the community composting – 

provided that the operation is not subject to the Local Enforcement Agency 

Notification or Permit regulations pursuant to the CCR Title 14 Division 7, 

Chapter 3.1, Section 17857.1. 

Comment #13: It is not clear why moisture content measurement requirements are needed 

relative to Rule 1133.1, except to exempt sources pursuant to paragraph (f)(3). 

Please clarify whether there are additional instances that moisture content 

measurements are needed. Please clarify the frequency and time during the 

composting cycle when composting measurements will be taken.

Response #13: Moisture content measurement requirements are also presented as a monitoring 

parameter to exempt a biomass power generation facility or a facility processing 

material as a biomass fuel for a biomass power generation facility from the 

holding time. The alternative parameter that the material temperature is below 

122 degrees Fahrenheit is also provided. Composting monitoring measurements 

are not taken into consideration in PAR 1133.1. When moisture content 

measurements are taken, at least 10 samples of chipped and ground greenwaste 

shall be taken from various locations of the pile on a given day. 

Comment #14: Please indicate the rule version, by year, of ASTM methods D4442 and D4444 

that are cited in PAR 1133.1(e), and how the District would handle a situation 

where the two moisture content test methods produce different results. 

Response #14: The rule version of ASTM methods was indicated in the rule as recommended. 

ASTM method D4442 (Standard Test Method for Direct Moisture Content 

Measurement of Wood and Wood-Base Materials) is the method that is used as 

the reference for calibrating and standardizing a hand-held moisture meter (with 

D4444). A hand-held moisture meter can be used to measure moisture content, 

but since the meter produces relative readings, it should be calibrated by the 

method D4442. This being the case, if the two methods differ in their results, 

D4442 takes precedence. 

SCAQMD IV-3 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

CARB Comments 

Comment #1: Table IV-2 of Appendix IV to the Preliminary Draft Staff Report mentioned that 

the average emission factors were determined by weighting the values based on 

greenwaste throughput. However, upon further evaluation of the document, the 

throughput values used to weigh the data are not included in the Appendix. We 

suggest including the throughputs for each composting operation so the reader 

can follow the calculation more clearly. 

Response #1: As staff attempted to harmonize the material holding time with the Title 14 

requirement (i.e., to remove within 48 hours of receipt or up to seven days 

maximum), there would be no emission reductions quantified from the PAR 

1133.1 requirements. Thus, staff decided to remove sections for stockpile 

baseline emissions and stockpile emission reductions from the staff report. 

Comment #2: In Table IV-2, it is not clear how the composite emission factor was calculated 

based on the average lbs/wet ton/day factor. We recommend more calculations 

be added to improve clarity. 

Response #2: The reader is referred to Response #1 of this section. 

Comment #3: The five facilities averaged together to obtain the stockpile and windrow 

emission factors are from throughout the state. Using the statewide average 

may artificially inflate the baseline for the South Coast because the South Coast 

values used in the average are on the low end for both the stockpiles and 

greenwaste. Is the assumption that the other greenwaste facilities in the South 

Coast region are less clean (from a VOC perspective) than the Inland Empire 

Composting Facility? We recommend that you explain the logic behind using a 

statewide average emission factor rather than the only data from the South 

Coast region. 

Response #3: The emission factor from the Inland Empire Composting Facility does not 

represent typical greenwaste composting operations currently being conducted 

in the South Coast region. Other air districts also did not consider using this 

emission factor because they thought that the emissions test was lacking in 

representing full life cycle emissions of VOC. The emission factors for the four 

(except Inland Empire) facilities are the currently available set of data that are 

considered to represent greenwaste composting operations in the South Coast 

District. Therefore, the weighted emission factor considers these four tests, 

along with the Inland Empire results. 

SCAQMD IV-4 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

CalRecycle Comments 

Comment #1: PAR 1133.1(d)(1)(A): Under existing state regulation, chip and grind sites 

which are not associated with a permitted composting operation or transfer 

station may not accept foodwaste. Foodwaste is not an acceptable material for 

landfill alternative cover or erosion control. Therefore, please delete this 

section or clarify that the chip or grind facility must have a transfer station 

permit in order to receive foodwaste. 

Response #1: The rule language has been revised such that foodwaste cannot be accepted at 

chipping and grinding facilities, unless otherwise allowed by the LEA. 

Comment #2: PAR 1133.1(d)(1)(E): This section conflicts with state regulation. Please 

delete. 

Response #2: Staff deleted this subparagraph as suggested. 

Comment #3: PAR 1133.1(d)(3)(D): Records of rainy days and wet weather conditions should 

only pertain to composting facilities. 

Response #3: Although chipping and grinding operations can occur on rainy days, the original 

intention of this requirement was to allow additional time for chipping 

operations, if the normal operations are impeded by rain events and the operator 

cannot effectively remove the material within 48 hours of receipt or up to seven 

days maximum, with approval from the LEA. 

Comment #4: PAR 1133.1(d)(3)(E): Records of moisture content should only pertain to 

biomass power generation facility stockpiles, as those facilities are exempt from 

Title 14 Division 4 Chapter 3.1 Section 17852 of the CCR. For stand-alone 

chip and grind facilities, there is no exemption for moisture content in existing 

state regulations. For CDI facilities, the materials must remain under 122 

degrees Fahrenheit at all times. 

Response #4: An exclusion from material holding requirements has been added for biomass 

fuel material. The existing moisture content exemption relative to curbside 

greenwaste (i.e., grass and leaves) is not proposed for or within the scope of the 

amendment. 

Comment #5: PAR 1133.1(d)(4): Wet weather conditions should not apply to non-compost 

facilities, as Title 14 Division 7 Chapter 3.1 Section 17852(a)(10)(ii) of the 

CCR does not contain an exemption beyond 7 days for wet weather. 

Response #5: This element is necessary for landfill operations. 

Comment #6: PAR 1133.1(e): Moisture content measurement section should only apply to 

biomass power generation facility stockpiles. 

Response #6: The reader is referred to Response #4 of this section. 

Comment #7: Why is foodwaste measured by weight but manure measured by volume? It 

would make sense to use the same standard. Weight is straightforward to 

measure and less subjective. 

SCAQMD IV-5 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Response #7: Manure measured by volume has been established in District Rule 1133.2 

relative to co-composting. The definition should be on a consistent basis with 

that in Rule 1133.2 and Rule 1133.3. 

Comment #8: There may be circumstances where a passively aerated static pile, such as one 

that has large pipes embedded in it, could provide sufficient aeration to avoid 

anaerobic conditions. Please consider allowing passively aerated static piles 

when covered a pseudo-biofilter and pursuant to the approval of the APCO. 

Response #8: Staff revised the proposed rule language such that a minimum requirement for 

composting system design is no longer included. That is, there is no limitation 

in the composting system. Operators can continue with their respective 

techniques for composting. 

Comment #9: While 5% oxygen content is considered ideal, it is difficult to achieve in 

practice, particularly in actively decomposing piles, where microbes consume 

oxygen rapidly. 5% oxygen will be nearly impossible to maintain without very 

frequent turning which probably result in huge increases in diesel and 

particulate matter (PM) emissions, and costs from the turning operation. More 

likely, achieving 5% oxygen content will be impossible when a pile is covered 

with a 6 inch layer of finished compost. At a minimum, please remove the 

oxygen requirement during the time when a compost cap is applied. We prefer 

you make the oxygen testing for informational purpose only, until such as time 

as we can be certain the instruments are reliable and an applicable standard can 

be deduced. 

Response #9: Staff agrees and has removed this requirement from the proposed rule. 

Comment #10: Please make an exception for operators who apply water during turning using a 

turner which is equipped with water spraying technology. This best 

management practice wets the composting feedstock evenly and is expected to 

reduce emissions during turning. It also represents efficient water and diesel 

fuel use. 

Response #10: Staff added this suggestion to the rule. 

Comment #11: Too many re-applications of the compost cap are impractical. Regulation does 

not mandate Process to Further Reduce Pathogens (PFRP) occur during the first 

22 days, but many operators prefer to document their pathogen reduction early 

in the process, because the materials may not get hot enough later on. 

Applications of a thick blanket of material could compromise operators’ ability 

to maintain sufficient temperatures during the legally required pathogen 

reduction period. Therefore, we recommend the following scheme: 

1) Applying a 6 inch cap of overs if available and finished compost if overs 

are not available to initial windrow; 

2) At the first turn, applying water for the next five turns, if operator has 

begun pathogen reduction. If the operator turns but has not begun 

pathogen reduction, then they should re-apply the cap. Operators are 

already required to maintain a log of when pathogen reduction begins and 

ends; and 

SCAQMD IV-6 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

3) When pathogen reduction is finished, the operator may apply one more 

cap of unscreened finished materials for additional clean air benefits. 

Response #11: Staff is proposing to place the finished compost cover on the top of initial pile 

for the first seven days of the active phase composting, during which the pile is 

to not be turned, and watering afterward to the surface of the pile within six 

hours before the initial and subsequent turnings during the remaining active 

phase period of composting. Please refer to subparagraph (d)(2)(B) of the 

revised PR 1133.3. 

Comment #12: Please add a requirement which suspends capping during the ozone season 

(from May 1 to October 1). The capping operations are substantial, and the 

diesel equipment needed for these operations will result in NOx emissions. The 

ozone season coincides with periods of intense sunlight, hence ozone 

exceedences are very rare during the winter months. 

Response #12: The revised rule no longer requires repeated capping of finished compost. 

Therefore, the requirement suggested for the ozone season is not needed. 

Comment #13: Source testing for a large biofilter costs around $100,000 per occurrence; a twoyear frequency is not cost effective for an engineered system. Two reasonable 

methods for ensuring the efficacy of an installed biofilter are to place a limit on 

the shrinkage of the filter medium, or to conduct a smoke test every two years. 

With these suggestions in place, it would be reasonable to extend the time frame 

between source tests to 5 years or more. 

Response #13: While there have been tests that have cost as much as the amounts stated, most 

of the tests conducted that cost that much were research oriented tests that 

involved several operating scenarios, developing site-specific testing methods 

and techniques, or were unique and difficult to test configurations. As the 

testers gained experience with biofilter testing, and as more testers have entered 

the market for competition, testing costs have gone down. A test that recently 

took place on a greenwaste and foodwaste composting facility with a biofilter, 

was conducted for ~$10,000, including source testing and reporting. It is likely 

that this lower testing cost is more representative of those that will be available 

in the future, unless further competition drives that cost lower. In the PR 

1133.3, staff revised the source testing frequency from every two years to every 

three years. 

SCAQMD IV-7 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Public Comments on PAR 1133.1 

(a) Purpose 

Comment #1: The primary goal of PAR 1133.1 should match with that of PR 1133.3, which is 

reducing VOC and ammonia emissions from the regulated facilities. Activities 

permitted in this rule that do not promote emission reductions include the 

continuation of alternative daily cover (ADC) without restrictions, and other 

practices in conflict with PR 1133.3 and other regulations. 

Response #1: At landfills located in the South Coast jurisdiction, ADC is placed as a cover 

material onto the surface of a landfill each day, and is generally not stockpiled 

for longer than 48 hours. Their material holding time is consistent with the 

holding time required in PAR 1133.1 and state regulation, Title 14.

(c) Definition 

Comment #1: Please add a definition of the undetermined term “finished compost.” 

Response #1: Staff added a definition of finished compost as suggested. 

Comment #2: Chipping and grinding definitions, holding times, and foodwaste parameters 

need to be consistent with PR 1133.3 and Title 14. 

Response #2: Staff made some of the definitions and requirements consistent with PR 1133.3 

and Title 14, such as “active compost” and “material holding time.” 

Comment #3: Definition of “static pile” has no meaning relative to “active compost” (in Title 

14) which is defined by temperature in the pile, not processing method. 

Response #3: Staff removed the term “static pile” from the rule and refers to composting 

generically. 

(d) Requirements 

Holding Times

Comment #1: Stand alone chipping and grinding facilities (those not co-located at MRFs, 

transfer stations and/or landfills) are not allowed to handle source-separated 

food scraps without additional permitting. The requirements in PAR 1133.1 

need to be consistent with, and at a minimum, not contradict with existing 

requirements for these types of facilities under Title 14. 

Response #1: Staff modified the requirement such that foodwaste cannot be accepted at 

chipping and grinding facilities, unless otherwise allowed by the LEA. 

Comment #2: Holding time requirements should be made consistent between PAR 1133.1 and 

PR 1133.3. 

Response #2: Staff made holding time requirements consistent as recommended. 

SCAQMD IV-8 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Comment #3: Holding time requirement differs based on the source of greenwaste. It should 

be based on actual material moisture and nitrogen rather than on “source.” 

Response #3: The rule no longer requires different holding times based on the source of 

greenwaste, rather it requires the same 48 hours or up to seven days maximum 

holding time on any type of greenwaste, with approval from the LEA. 

Comment #4: Rule should better define “used on site.” It should be clearly defined to mean 

“utilized on site” and not “stockpiled.” If this rule is to reduce VOC emissions, 

the District should regulate how the material is handled once it arrives at its 

destination within the District. 

Response #4: Staff changed the rule language from “used on site” to “utilized on site.” 

Comment #5: Under existing state regulation, chip and grind sites which are not associated 

with a permitted composting operation or transfer station may not accept 

foodwaste. Foodwaste is not an acceptable material for landfill ADC or erosion 

control. Therefore, please delete this section or clarify that the chip and grind 

must have a transfer station permit in order to receive foodwaste. 

Response #5: Staff made changes to the rule so that chip and grind sites cannot take 

foodwaste, unless otherwise allowed by the LEA. 

Comment #6: The current rule allows various holding times based on the origin of green 

materials, which conflicts with existing state regulation requiring removal of 

materials from the site within 48 hours of receipt. 

Response #6: Revised rule language is now harmonized with state regulation Title 14. 

Regardless of origin, greenwaste needs to be processed and removed within 48 

hours of receipt or up to seven days maximum, with approval from the LEA. 

Comment #7: Holding time for composters should be listed in PR 1133.3 for ease of 

understanding. 

Response #7: Staff has specified the holding time requirement for composters as suggested. 

Static Piles/Stockpile Operations

Comment #8: Under the current proposed rule, stockpiling green material effectively allows 

static pile composting at a non-permitted chipping and grinding facility, which 

conflicts with state regulations. Under Title 14, static pile composting would 

require a composting permit. Chipping and grinding operations are required to 

keep materials below 122 degrees Fahrenheit. Any green material achieving 

this temperature at a facility is considered active composting and thus the 

facility would be required to obtain a composting facility permit. 

Response #8: Specification of stockpiling and static pile requirements were removed from the 

proposed rule provisions. This revised proposed rule essentially applies to 

chipping and grinding activities to produce materials other than active or 

finished compost by means of any type of composting methods. 

Comment #9: Static pile is a legitimate composting method, as decomposition of organic 

materials in the piles can reach the temperature of composting allowed for under 

SCAQMD IV-9 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Title 14, Section 17868.3. Therefore, it should be part of Rule 1133.3 and not 

Rule 1133.1. PR 1133.3 should allow it to be used as a “partial composting” 

process with a broader range of retention times (for example, from 14-21 days) 

without the regulatory burdens of the full composting process. 

Response #9: Static pile composting requirement was removed from PAR 1133.1. The PR 

1133.3 no longer requires specific type of composting method and specifies 

BMPs for the active phase only. 

Comment #10: Adding finished compost to a pile of freshly ground material will assuredly 

cause the pile temperature to rise above 122 degrees Fahrenheit as the compost 

will inoculate the new materials with additional microbes. 

Response #10: Adding finished compost to a freshly ground green material is no longer 

required under PAR 1133.1. Mitigation measure requirements were deleted. 

Comment #11: Stockpile operations for composters should be moved to PR 1133.3. 

Response #11: The reader is referred to Response #7 of this section. 

Comment #12: The finished compost cover on chipped or ground greenwaste should be deleted 

and compost that is cured (low moisture) should be allowed to remain on-site 

for as long as necessary. 

Response #12: The finished compost cover requirement was deleted and is no longer proposed 

in the revised PAR 1133.1. Stockpiling cured compost on-site is out of scope 

for PAR 1133.1 and PR 1133.3 does not limit storage of finished (cured) 

compost as the process is complete. 

Recordkeeping

Comment #13: Assuming that the landfill does not perform the chipping and grinding or 

composting onsite, rather the chipped greenwaste is brought to the landfill: 

oWill landfills be required to register and provide annual updates per Rule 

1133? The intent of Rule 1133 reads to establish a registration process 

and database for composting and chipping and grinding facilities that are 

in the business of producing compost. It is suggested that landfills are 

exempt from this requirement since we are simply the end users of a 

product that is manufactured by other entities. 

oThe greenwaste is applied to the working face the day it is received. We 

do not take moisture content measurements. If the greenwaste is applied 

the day it is received, we are not sure what value these measurements 

would have. We suggest exempting this requirement for landfills that do 

not exceed the 3 day maximum storage time. 

oAt landfills, we are simply the customers receiving shipments of chipped 

greenwaste. We do not have information as to whether the shipment of 

greenwaste originated from curbside, non-curbside, or mixed greenwaste 

sources. That information would need to come from the product 

manufacturer. 

SCAQMD IV-10 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Response #13: Staff revised the language such that the operator of a landfill or biomass power 

generation facility would be exempt from the requirements of recordkeeping, 

provided that the operator does not perform chipping and grinding operations 

on-site. 

Wet Weather Conditions

Comment #14: Wet weather exclusions should be removed because chipping and grinding can 

be and is conducted during rainy periods, and Title 14 does not contain an 

exemption for wet weather. 

Response #14: The reader is referred to Responses #3 and #5 of the CalRecycle Comments 

section. 

Moisture Content Measurement

Comment #15: Instead of ASTM tests of moisture content, please allow in-situ monitoring of 

moisture in the chipped and ground greenwaste pile using a soil moisture 

monitor probe. 

Response #15: ASTM methods D4444 is the standard test method for standardizing and 

calibrating hand-held moisture meter. A hand-held moisture meter should be 

calibrated by the method D4442. Therefore, hand-held moisture meters are 

already allowed for use in the rule. The reader is also referred to Response #14 

of the US EPA Comments section. 

Comment #16: Further studies should be performed to determine if 30% is an appropriate value 

to retard decomposition and is achievable under current operation. 

Response #16: The 30% level of moisture content has already been established in the previous 

rulemaking based on staff research. Decomposition of chipped green material is 

retarded at below 30% moisture content. As an example, the moisture content 

of chipped green materials used as biomass fuel is maintained at less than 30 

percent to avoid decomposition. 

Miscellaneous 

Comment #17: What if the chipping/grinding operation is conducted on-site by an outside 

contractor that brings the equipment on site as needed; does the rule apply to the 

contractor operating the equipment or the facility operator at the site receiving 

the greenwaste? 

Response #17: The facility operator is responsible for compliance with the rule holding time 

and processing requirements as they are receiving the material, contracting with 

those that bring the chipping/grinding equipment on-site, and are therefore 

responsible for handling of the chipped and/or ground material. The only 

exception is if the equipment meets the definition of portable equipment, that is 

equipment with a manufacturer’s rating of 170 brake hp or less, which is 

exempt under the rule. 

SCAQMD IV-11 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Public Comments on PR 1133.3 

General Comments 

Comment #1: Explain the physical and time boundaries that were assumed when determining 

the centralized organics processing adverse impacts to the atmosphere, 

including all the transformations and exchanges that take place in the soil, 

terrestrial vegetation, and atmosphere over the life of the materials. 

Response #1: Relative to the rule proposal, emissions baseline and reductions factored in 

emission profiles developed were based on full cycle composting. Conducting a 

life cycle analysis, as suggested, is outside the scope of analysis for this rule 

development effort. 

Comment #2: Evaluate the impact of this regulation on the carbon cycle. One benefit of 

composting is that it enriches the soil with carbon, increase the soil’s carbon 

reserve, decreasing carbon available in the atmosphere. 

Response #2: Evaluating the impact of this regulation on the carbon cycle is beyond the 

purpose and scope of this regulation. Although composting is an 

environmentally favorable treatment method of recycling organic waste, it is 

also true that composting operations emit VOCs and ammonia that partake in 

the formation of ozone and fine particulates. 

Comment #3: The District should promote alternative organic residual processes such as 

backyard composting since it conserves and reduces energy and emissions by 

eliminating transportation and processing operations. 

Response #3: The proposal does not alter existing exemptions for backyard composting. 

Comment #4: We expect to see, in the socio-economic analysis, a comprehensive whole 

systems analysis of costs and benefits, which includes economic assessments of 

soil amendment, fertilizer, energy production and landfill uses of organics, 

using competitive tipping fees, competitive prices of products, and all current 

and proposed rule requirements affecting: processing, operational, analytical 

testing, storage and marketing costs. 

Response #4: The suggested micro systemic analysis requires tedious and costly construction 

of individual elements, which is beyond the scope of analysis the District staff 

performs in support of rule development. That being said, the data necessary or 

economic model for such micro analysis is not available and the suggested level 

of analysis cannot be done. Additional costs and benefits associated with the 

proposed rule relative to the existing four-county economy are assessed through 

the Regional Economy Modeling Inc. (REMI) PI+

 model for the total 

socioeconomic impacts of the proposed rule on affected facilities and the entire 

economy in the four-county region. 

Comment #5: Consider composting as a VOC reduction technology for non-composted 

material. 

Response #5: The reader is referred to Response #2 of this section. 

SCAQMD IV-12 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

(c) Definitions 

Comment #1: Greenwaste mixed with up to 20% manure is still defined as greenwaste. 

Response #1: Staff disagrees. Greenwaste means organic waste material generated from 

gardening, agriculture, or landscaping activities. Manure means excrement of 

animals, such as barnyard or stable dung, often with discarded animal bedding, 

and cannot be defined as green material. Up to 20 percent manure, by volume, 

is allowed to be composted with greenwaste for the purpose of greenwaste 

composting because it is difficult to completely separate manure from animal 

bedding. This 20 percent allowance was already established in existing Rule 

1133.2 – Emission Reductions from Co-Composting Operations. 

Comment #2: Increase percent manure to 49 percent for the greenwaste composting operations 

to be more flexible. 

Response #2: Requirements for greater than 20 percent manure, by volume, are already 

established as co-composting under Rule 1133.2. 

(d) Requirements 

Composting System

Comment #1: Static pile is another composting technique, just like a windrow. It must meet 

the same time and temperature requirements to make a compost product. The 

rule should allow both static pile and windrow composters to continue with their 

respective techniques as there are few enough of both in the South Coast. 

Response #1: The reader is referred to Response #8 of the CalRecycle Comments section. 

Comment #2: There is no basis for the exclusion of “passive pile” composting (which is more 

commonly referred to as “static pile”). Static pile composting (which has 

limited turning) would not include these VOC releases and may in fact have 

lower VOC emissions overall. Unless the District can provide research that 

shows that passive pile composting (not stockpiling) has larger uncontrolled 

emissions than windrows, passive pile or static pile composting should be 

allowed under PR 1133.3. 

Response #2: The reader is referred to Response #8 of the CalRecycle Comments section. 

Windrow Management

Comment #3: PR 1133.3 should not refer back to requirements in PAR 1133.1. If there are 

required holding times for composting facilities, they can be listed in PR 

1133.3. 

Response #3: Staff revised rule language to list required holding times for composting 

facilities in PR 1133.3, not referring to PAR 1133.1. 

Comment #4: Moisture meters currently on the market are generally developed for soil 

moisture and have limited utility with compost. The Rule should allow 

flexibility in how moisture is measured, such as the “squeeze test” used by 

SCAQMD IV-13 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

SJVAPCD in their Proposed Rule 4566 or using a Koster Moisture Tester 

without separate Executive Officer approval. 

Response #4: Staff has concluded there is a lack of evidence that emissions will be negatively 

impacted if moisture falls below 40%. Thus, the moisture measurement is 

removed and no longer required in PR 1133.3. 

Comment #5: Effective windrow compost operations have a track record of turning frequently 

enough to maintain adequate oxygen levels and to avoid anaerobic 

conditions. In fact, operators have an incentive to do so, since failing to do so 

would slow production and waste money. In addition, having a 5% oxygen 

level has not been shown to reduce emissions and may be impractical to 

maintain without very frequent turning. Therefore, it seems unnecessary to add 

an oxygen monitoring requirement. 

Response #5: The requirement has been deleted from PR 1133.3. 

Mitigation Measures: Water Irrigation and Finished Compost Cover

Comment #6: The whole composting process should be perceived as mitigation and the basis 

of reduction should be from non-composted material processes. 

Response #6: Staff agrees that composting is a process turning organic waste into a useful 

product. However, composting is still an emissive process. Those emissions 

may be inevitable, but staff believes such emissions could be reduced further 

with appropriate mitigation measures. Therefore, the reductions are measured 

from an uncontrolled composting pile as opposed to natural degradation. 

Comment #7: The use of a finished compost cap should be encouraged when the material is 

available, but at the minimum both chippers and composters should be required 

to use water irrigation on the pile in the initial period after the greenwaste is 

first ground. This will lead to a “level playing field” for both chippers and 

composters and also control emissions at their most critical period. 

Response #7: Requirements for both chippers and grinders will be handled separately in Rule 

1133.1. The revised rule proposal has more stringent requirements for material 

holding time than the earlier version of the rule and conforms to the Title 14 

state regulation. 

Comment #8: There is no discussion present of the requirements for water application 

following rain events. Oversaturation of the materials has been previously 

identified as a poor management practice, potentially leading to anaerobic 

conditions. Additionally, conformance with Water Board regulations may 

preclude or limit over application of water at compost sites. 

Response #8: Staff added an exception for water application relative to a rain event in which 

the aim is to ensure wet material before turning without indiscriminate water 

application. 

Comment #9: We support the surface water application as mitigation, but are concerned that 

the basis for the threshold being applied (that is, based on throughput) is 

inappropriate. Please explain. 

SCAQMD IV-14 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Response #9: Staff revised the rule language so that no threshold is imposed for the surface 

water application and water applies to every facility regardless of size. 

Comment #10: By requiring the compost cap throughout the active phase process, the District 

Rule will necessitate the multiple handling of the same material. This will 

require an operator to emit more criteria pollutants from mobile sources. This 

practice could also have significant GHG impacts from the increased use of 

diesel fuel. We suggest the compost cap be removed from this rule until such 

time as the District can demonstrate its cost-effectiveness as mitigation and that 

its use will not have an additive emission impact in other criteria pollutants such 

as particulate, GHG, and/or NOx. 

Response #10: Staff revised the rule such that the finished compost cover is required to apply 

to initial active piles only for the first seven days of the active phase, and 

watering is required thereafter for the remaining duration of the first 15 days of 

active phase composting. NOx and PM Emissions for finished compost cover 

are under the CEQA daily threshold. 

Comment #11: Because there are relatively few emissions to control after the first two weeks, 

there should be no further reason to cap the pile, and this will also lead the 

composters to believe that they are not being put at an economic disadvantage 

to the shredders. 

Response #11: The reader is referred to Response #10 of this section. 

Comment #12: Records already include pile moisture content for water. By adding 

“applications of water” makes the recordkeeping redundant. 

Response #12: Revised rule language no longer requires pile moisture content measurement. 

Applications of water to the active phase piles would be required the 

recordkeeping. 

Forced Aeration System

Comment #13: We agree with the use of the forced aeration system in regards to the 10% 

foodwaste, by weight. 

Response #13: Staff appreciates your support to the amount of foodwaste, by weight, to be 

composted with addition of an air pollution control device. However, staff 

decided to pursue a modified threshold that combines the percent limit of 

foodwaste with a facility-wide annual throughput. 

Comment #14: It is not clear why the aerated static pile composting process is required for 10% 

or more of foodwaste in the system. It would be helpful to equate this to the 

amount of VOCs are increased by the addition of foodwaste. 

Response #14: Since food scraps contain a larger fraction of easily biodegradable and volatile 

material than greenwaste, composting foodwaste emits more VOC than 

composting greenwaste alone. In the Modesto study published by the 

CalRecycle in 2007, composting of 15% foodwaste windrow emitted as two-tothree times higher VOC emissions as composting of a greenwaste windrow 

SCAQMD IV-15 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

without foodwaste. In addition to VOC emissions, decomposing putrescible 

foodwaste can cause odor problems. 

Staff carefully investigated the current foodwaste composting operations and 

decided to augment the 10 percent, by weight, foodwaste limit with actual 

annual foodwaste threshold. Therefore, in the revised rule language, an 

emission control technology meeting 80 percent control would be required for 

any active phase pile containing foodwaste of 10 percent or more, if an operator 

intends to (or does) process greater than 5,000 tons per year of foodwaste 

throughput (source-separated or mixed). Up to this throughput threshold, there 

is no percent restriction of containing foodwaste in the greenwaste composting 

operations. 

Comment #15: Compost emission factors are operation specific, and thus inappropriate to apply 

a universal emission factor to all operations. 

Response #15: Staff agrees that emissions can vary. However, consistent testing on like 

operations can be conducted. Compost emissions can vary by conditions (e.g., 

feedstock) even for the same operation. This is why composite emission factors 

are developed from currently available emission tests conducted at respective 

composting facilities with similar operations in the South Coast District. 

Comment #16: The mandated emission factor is set so high that virtually all of the 16 affected 

composting facilities’ and, particularly, future new composting facilities’ 

composting VOC emissions will certainly exceed the District’s significance 

threshold of 55 lbs/day. For instance, using the 55 lbs/day threshold as the 

maximum mitigated VOC emissions, 80% mitigation efficiency of the required 

forced aeration system, and the mandated uncontrolled baseline emission factor 

of 4.67 lbs/ton, virtually no greenwaste composting facility will be able to have 

a throughput of greater than 60 tons per day without preparing an 

Environmental Impact Report under CEQA. 

Response #16: The baseline emission factor of 4.67 lbs/ton for VOC is determined from 

emissions test data that are currently available from respective greenwaste 

composting operations that are representative of local operations. For the 

purpose of this rule effort, an emission factor of 4.25 lbs VOC/ton throughput 

for the active phase only of composting would be considered. It should be 

noted that this factor is for uncontrolled emissions in the absence of site-specific 

source tests. Source testing under the rule relative to the emission control 

device will provide a more site-specific emission characterization. CEQA will 

not be triggered unless the facility makes a modification requiring a 

discretionary approval from a government agency. 

Comment #17: The control efficiency of 80% by weight for VOC and ammonia emissions is 

not viable for biosolids composting operations. Since these operations have the 

potential to emit lower VOC and ammonia emissions, a more reasonable and 

achievable control efficiency is 75%. 

Response #17: Greenwaste composting operations have the potential to emit higher VOC 

emissions and lower ammonia emissions than biosolids composting operations. 

SCAQMD IV-16 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

SCAQMD IV-17 July 2011 

Recent source tests conducted for biosolids composting operations showed 

much higher control efficiencies than the required 80%. 

Comment #18: The requirement of an 80% overall system control efficiency for VOC and 

ammonia seems high given the lack of operational data on the performance of 

aerated static pile (ASP) and biofilter systems for green material with more than 

10% food scraps. Please provide more evidence that this is achievable in 

commercial application on the proposed regulated feedstocks (i.e., not 

biosolids). 

Response #18: Emissions test data on the performance of ASP and biofilter system for green 

material with food scraps is available. A commercial application1 achieved 

90% reduction in VOC emissions (as total hydrocarbon) for ASP and biofilter 

system composting 25% food scrap and 75% greenwaste. A different 

commercial application2 of a forced aeration system using a fabric membrane 

cover has multiple data sets from demonstration projects and existing facilities 

showing more than 95% reduction in VOC and ammonia emissions from mix 

recipes up to 45% foodwaste by weight compost pile without the need for a 

biofilter.   As public and regulatory interest on foodwaste composting is on the 

rise, staff expects additional emissions data to be collected on the performance 

of an emission control system for foodwaste windrow mixed with greenwaste in 

the future. 

Source Testing

Comment #19: The current methodology for source testing, flux chamber testing, is very 

expensive and not warranted for aerated static pile composting biofilters. The 

test costs between $50,000 and $100,000 per test. Testing at the initial 

construction of the biofilter in addition to every two years is cost prohibitive. If 

an operator is adhering to best management practices as required in paragraph 

(d)(2)(H), and the equipment installation, maintenance and best management 

practices are documented, the testing will be redundant. Our recommendation 

is that the District conduct a test with a portable flux chamber on the surface of 

the biofilter within three months of the start of operation. If at this time, or at 

any other time that a portable flux chamber is given, the TNMNEHC is over 

100 ppmv, a source test will be required. The portable flux chamber test can be 

required if nuisance complaints demonstrate obvious neglect or negligence by 

not adhering to best management practices. 

Response #19: The reader is referred to Response #13 of the CalRecycle Comments section. 

Comment #20: Provide new source test method for compost operations. 

Response #20: The flux chamber test method, modified by the District, has been used to 

determine emissions from compost piles and biofilter controls. A new source 

 

1 ECS, 2011. Comparison of Air Emissions from the ECS AC ComposterTM and Turned Windrow during 

Composting of a Food Waste and Green Waste Mixture. White Paper ACC-2. 

2

 Data available for GORE® Cover can be requested by contacting W. L. Gore & Associates. 
PAR 1133.1 and PR 1133.3 Final Staff Report 

test method is not required for compost operations, but staff will work with the 

industry if there are suggestions for new methods in the future. 

(g) Exemptions 

Comment #1: “Municipal composting” or “centralized composting” should be exempted. We 

believe that the benefit of centralized composting to soil, water, and air are 

much more preferable to the alternatives. Our mulch give-away program 

recycles organic residuals (25% of the City green residuals and 75% by 

contractors) through giveaways to residents and farms. We operate at a fiscal 

deficit and any additional costs would make it more difficult to maintain our 

operations. Our vision is to increase our give-away program and recycle more 

residuals back into the local communities. 

Response #1: Municipal composting or centralized composting collects curbside and noncurbside greenwaste which are main components of greenwaste composting 

feedstock. Although the compost product is given away to the local 

communities for free, the magnitude of the centralized composting would 

typically be large. Thus, staff did not add an exemption for centralized 

composting to PR 1133.3. 

Comment #2: The type of community composting needs to be more fully defined in order to 

determine at what volume level they should be exempted from in this 

rulemaking. 

Response #2: The proposed rule has been revised such that composting facilities as listed in 

paragraph (g)(3) are exempt, provided that the operation is not subject to the 

Local Enforcement Agency Notification or Permit regulations pursuant to Title 

14 Division 7, Chapter 3.1, Section 17857.1 of the California Code of 

Regulations. 

Miscellaneous 

Comment #1: It is recommended that high solids anaerobic digestion (HSAD) would be 

classified as a pre-processing step for composting facilities. The organic 

material waste is digested in an enclosed unit. The resulting material (a 

combination of green and food) can be transferred to a compost facility. These 

units are enclosed, and are also designed to include enclosure for the delivery of 

undigested materials. 

Response #1: Under this proposed rule, composting is limited to be aerobic decomposition of 

organic waste material. Currently, anaerobic digestion (AD) is not being 

considered as an option of composting organic materials. Considering growing 

interest to the AD system, however, staff may examine the AD system as a preprocessing technology for composting processes. 

SCAQMD IV-18 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Comments on Preliminary Draft Staff Report 

Comment #1: Landfill gas recovery systems (in the remaining states) have little impact on 

VOC emissions from ADC or beneficial reuse, mainly due to the lag time 

between the disposal time and their installation. Additionally, the lengthy 

residence time allowed for processed organic materials at landfills in this draft 

rule is inadequate given that over twice as much material is used for ADC as is 

composted in the Basin. 

Response #1: The statement of the landfill gas recovery systems in the remaining states was 

deleted. Landfills in South Coast have been controlled for VOCs and methane 

for decades. In addition, ADC materials must be applied to the landfill surface 

at the end of the operating day pursuant to Title 27 of California Code of 

Regulations. 

Comment #2: Recycled water is not available in all places, and many composters may be 

reluctant to use it because it generally contains higher levels of salt. Salt build 

up is a concern, particularly in foodwaste and manure composting, but also with 

greenwaste. Furthermore, once compost has passed the pathogen reduction 

stage, untreated surface water cannot be used for irrigation of piles. 

Response #2: According to the existing composting facility operators, some facilities use all 

potable water and others use all reclaimed or canal water. Salt content has not 

been raised as a relevant local issue, as it pertains the watering BMP. 

Comment #3: CalRecycle recently completed emissions research using “overs” (by-product of 

finished compost screening) as a pseudo-biofilter compost cap. Overs are 

similar to biofilter material, and were effective in reducing ozone formation 

from composting emissions. 

Response #3: The definition of “finished compost” has been revised so that “compost overs” 

are included. Finished compost can be screened or unscreened, humus-like 

material and/or compost overs that have gone through pathogen-reduction 

period. 

Comment #4: Both the finished compost cap and irrigation measures proposed will impact the 

potential air movement and moisture content and increase the potential for 

anaerobic sections to exist, thus generating increased GHGs. 

Response #4: A finished compost cap is now required to be applied only one time after initial 

pile formation for the first seven days of the active phase. Irrigation is only 

required so that the three inches in depth of piles are wet. Staff expects excess 

moisture is also evaporated while turning the piles and will not lead to 

oversaturation and leaching issues. Thus, both measures would not increase the 

potential for anaerobic sections to develop. 

Comment #5: The application of finished compost was evaluated to the top surface of the 

windrow only. A more robust description of the compost cover requirement is 

needed to evaluate the proper application and amount of materials and labor 

needed to apply it. 

SCAQMD IV-19 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Response #5: The proposal requires the compost cover such that the top is covered to a depth 

of six inches, and tapers off as it goes down the pilesides. Thus, the application 

is adequate to cover the top half of the pile where most emissions emanate. 

Comment #6: The highest costs to apply the cover involve the lost sales of materials used for 

the compost cover and the potential loss of operating space between windrows 

in order to allow the use of a front-end loader to access the windrows. Windrow 

composting operations generally have 8 to 10 feet spacing between windrows; a 

loader would need more than twice that spacing in order to effectively 

maneuver between windrows in order to apply a compost cover. The amount of 

increased loader activity – in addition to other equipment to handle the compost 

cover application materials – will produce significant increase NOx emissions. 

These increased NOx emissions have not been assessed. 

Response #6: The proposed rule has been revised in response to this comment. The revised 

rule language only requires one-time finished compost cover application which, 

based on the staff assessment, would not produce significant increased NOx 

emissions, loss of production, or loss of operating space. 

Comment #7: In the Modesto Compost Study completed in 2006 by the CIWMB, the use of 

two compost inoculants reduced VOC emissions by 42% in the first week and 

14% for the first two weeks, but one of the additives was not re-applied in the 

second week. The specific products used in the Modesto study were GOC 

technologies formulas ASC 2500 and ASC 2600. The former is a topical spray 

applied to windrows. The latter is mixed into a new batch of materials. 

Because there are many makers of inoculants and other compost “starters,” and 

because rapid composting is beneficial for air quality, we urge you to include 

additives as a potential mitigation measure in your rule, and to allow additive 

manufacturers to submit research demonstrating the efficacy of their products. 

Response #7: Studies of the control efficiency of the chemical additives are limited and thus 

more research is needed for the efficacy prior to being considered as a VOC 

emissions mitigation measure under PR 1133.3. 

Comment #8: Data from SWIS is often misinterpreted, and Table 1 is misleading. The most 

recent CIWMB survey of the compost and mulch infrastructure statewide 

estimates about 9.3 million tons of compostable materials are handled statewide. 

Significant portions of these materials are handled in the Central Valley and in 

the Bay Area. 17 million tons in the four-county SCAQMD area is not 

plausible. We believe the District has the data, through Rule 1133, to formulate 

a more reasonable estimate. 

Response #8: Staff agrees that the initial estimated chipping and grinding throughput needs 

more work and attempted to update the throughput number. Furthermore, staff 

requested industry stakeholders and CalRecycle assistance to provide countylevel aggregated chipping and grinding throughput data. Although CalRecycle 

approved sharing county-specific data, confidentiality concerns prevented 

transmittal of the information. Staff will continue to work to refine this 

information. 

SCAQMD IV-20 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Comment #9: The Preliminary Draft Staff Report fails to adequately analyzed the importance 

of the chip and grind process as a first step in quantifying air pollutants and 

reducing emissions during the initial first few days of organics processing. 

About 10% of the greenwaste processed is used for compost, and remaining 

90% is used for mulches, boiler-fuel, ADC, and other end product application. 

It seems important for the District staff to first consider focusing on chip and 

grind processing to achieve the highest level of emission reductions before any 

attempt is made to reduce air quality emissions from composting. We would 

like to assist the District staff by having meetings with staff to discuss an 

accurate baseline inventory, appropriate emission reduction measures and 

strategies, permitting, source testing, etc. 

Response #9: Staff appreciated the opportunity to meet with industry stakeholders to discuss 

the above-mentioned issues. With input from the stakeholders, staff was able to 

improve rule language and data, but even industry representative had difficulty 

obtaining facility throughput data. Staff’s efforts in this area will continue after 

Board consideration of the existing proposal. 

Comment #10: All facilities receiving greenwaste should be included within PAR 1133.1, even 

where woodwaste is the dominant share. The greenwaste fraction at these 

chipping and grinding facilities should be managed according to the adopted 

rules, while the woodwaste could continue to be exempted. 

Response #10: The operator of any greenwaste chipping and grinding would be subject to PAR 

1133.1. If chipping and grinding takes place at a composting facility or colocated landfill or material recovery facility, the operator would be subject to 

PAR 1133.1, provided that the chipped materials are used for purposes other 

than composting. Woodwaste chipping and grinding continues to be exempt 

from PAR 1133.1. 

Comment #11: The throughput numbers of landfills are inaccurate and should be revised. 

CalRecycle website reports show that less than 1,000,000 tons were used as 

ADC at landfills within the District. We estimate that quite a bit less than onehalf of that amosunt is being composted. 

Response #11: Staff revised the throughput numbers for landfills. 

Comment #12: Throughput numbers of greenwaste composting should be revised to reflect 

accurate totals. 

Response #12: Throughput numbers of greenwaste composting have been revised based on a 

supplemental questionnaire to reflect more current information. Staff 

appreciates all the greenwaste composting operators who participated in the 

supplemental survey. 

Comment #13: Greenwaste being composted is a minor source of VOC emissions versus the 

vast majority of VOC resulting from green materials being processed in the 

District. VOC emissions from green material have peaks immediately after 

grinding, trailing off over time. It is unfair putting the bulk of the compliance 

burden on greenwaste composters. 

SCAQMD IV-21 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Response #13: PAR 1133.1 has been revised such that the operator of chipping and grinding 

needs to move material within 48 hours of receipt or up to seven days 

maximum, with approval from the LEA, which harmonizes with state regulation 

Title 14. This limited removal requirement intends to prevent inadvertent 

decomposition of green material during stockpiling that may result in VOC 

peaks after chipping. PR 1133.3 would require the similar holding time, as 

allowed by the LEA, and finished compost cover and water application to 

reduce emissions for the first 15 days of active phase composting. The 

compliance costs have been revised with additional information staff received 

from greenwaste composting operators. 

Comment #14: This cost effectiveness appears to be underestimated by a significant measure. 

There is no accounting for the loss of sales and the potential volume reductions 

at the compost sites due to the logistics of applying the compost cover. Even at 

these low estimates, a 10,000 ton facility could not afford to stay in business 

adding $5.30 per ton to product cost, based on the $53,000 annual cost. 

Response #14: The compliance costs and cost effectiveness have been revised to reflect the 

current proposed mitigation measures, based on the revised composting 

throughput, emission reductions, and cost data. The revised dollar amount of 

compliance cost per ton for adding a finished compost cover initially and 

watering before each turning would be approximately $1.15 per ton of 

throughput (as compared to $0.79 per ton of throughput for adding one time 

finished compost cover). 

Comment #15: The staff report indicates a facility cost of $0.62 per ton for the compost cover 

system to be used, based on the Modesto Study. However, a review of that 

study indicates that the study windrow was not turned and re-covered 

repeatedly, as a real production scenario would require. The draft rule defines 

the active compost phase as the first 22 days. Normal compost 

windrow operations do five turnings in the first 15 days. Therefore, one would 

expect five cover applications. Using the Modesto Study’s numbers, we 

calculated the cost to be $2.76 per ton for applying five sets of compost 

covers. However, this is too optimistic, because the Modesto example 

further lacks resemblance to a real life production scenario. The loader was 

able to maneuver freely in open space next to the test windrow, without other 

windrows cramping the operation. This is important, because almost all 

facilities have narrow drive aisles between windrows. 

Response #15: Staff revised the cost estimates for compost cover using the Bakersfield 

experiment data the commenter provided. With only one time application of 

compost cover, $0.79 per ton is the revised calculated cost (as compared to 

$1.15 per ton of throughput for adding an initial compost cover and watering 

before turning). If there is enough space for a loader to turn the windrow, there 

should be little problem to maneuver the loader to apply finished compost cover 

on the initial pile for that cycle. 

Comment #16: Using an average diesel consumption rate of five gallons per hour per truck or 

machine, our Bakersfield exercise indicates it will take one gallon of diesel fuel 

SCAQMD IV-22 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

to apply every 100 feet of compost cover (each time). If our facility had to 

apply five covers to each of the 132,000 linear feet of windrow we handle each 

year, it would take 6,600 extra gallons of diesel fuel per year. 

Response #16: Compost cover cost was calculated using an average diesel consumption rate of 

five gallons per hour per machine using the same data as provided in the 

Bakersfield exercise. The proposed rule now requires only one time covering 

of the pile with finished compost and the calculated diesel use has been revised 

accordingly. 

Comment #17: The largest source of emissions in the industry sector was ignored by 

disproportionately placing the burden of emission reductions on composters. 

Response #17: PAR 1133.1 (chipping and grinding rule) is tightening a green material holding 

time in existing Rule 1133.1 such that the material must be processed or 

removed within 48 hours of receipt, or up to seven days maximum, with 

approval from the LEA, to reduce inadvertent decomposition during 

stockpiling. This amended requirement is to harmonize with the state regulation 

that has already been required under Title 14. Therefore, the proposed 

amendment would minimize unnecessary emissions, but no emission reductions 

would be quantified for the chipping and grinding industry sector. 

Comment #18: Appendix I of the Preliminary Draft Staff Report does not provide enough 

information about the establishment of 5% oxygen concentration is important to 

the emission rates. The accuracy of annual composting throughput is also 

doubtful. 

Response #18: Appendix I of the Preliminary Draft Staff Report summarizes results from a 

2007 survey that the District staff conducted to understand greenwaste 

composting operations in the South Coast. Although the information in the 

Appendix I still informative, some of the data (e.g., the list of existing facilities 

and annual composting throughput) have been updated elsewhere in the staff 

report. To avoid unnecessary confusion, staff has removed the 2007 survey 

results in the Draft Staff Report. 

Miscellaneous 

Comment #19: It would be helpful if copies of all comments were included with the 

information provided at the public meetings. 

Response #19: All comments received in regard to rules and staff report are summarized in this 

appendix of this staff report. Copies of all comments to the CEQA document 

will be included in the respective assessment documents. Those comments are 

public information and available on request.

SCAQMD IV-23 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

May 10th Working Group Comments (May 3, 2011 version of the rules)

US EPA Comments 

Comment #1: In order for EPA to approve a PAR 1133.1 amendment to the SIP, the District’s 

staff report should demonstrate that any relaxation of current SIP requirements 

is consistent with Clean Air Act (CAA) Section 110(l) requirements. 

Response #1: PAR 1133.1 tightens material holding requirements of the existing Rule 1133.1 

and thus would not relax the current SIP requirements. 

Comment #2: Under the PAR 1133.1, facilities that chip and grind greenwaste and foodwaste 

would be no longer subject to Rule 1133.1, unless they are permitted by the 

LEA to handle foodwaste. The District’s staff report should explain how this is 

consistent with CAA Section 110(l) if: (a) the LEA permit requirements are less 

stringent than the current rule requirements for foodwaste, and (b) there are 

chipping and grinding facilities in the District that are allowed to chip 

foodwaste without an LEA permit. 

Response #2: Under Title 14, the LEA permit for chipping and grinding facilities does not 

allow receiving food material at the facility and PAR 1133.1 is to harmonize 

with Title 14 regulation for foodwaste. Staff understands that a chipping and 

grinding permit is issued by the LEA and thus, there is no chipping and grinding 

facility in the District that is allowed to chip foodwaste without an LEA permit, 

which has been more stringent in general than existing Rule 1133.1. 

Comment #3: The rule requirements of PR 1133.3 have been changed since the January 25, 

2011 Workshop version. The District’s staff report should include the expected 

emission reductions based on the latest proposed version of the rule. 

Response #3: The expected emission reductions with the latest proposed version of the PR 

1133.3 are included in the staff report. 

CalRecycle Comments 

Comment #1: PAR 1133.1 (c)(1): The new term “composted mulch derived from partially 

composted greenwaste” is puzzling. Finished compost may be used as mulch, 

and oversized materials may be screened out of finished compost and used as 

mulch. If you are attempting to describe as partially composted mulch product 

which has been through a complete pathogen reduction process, the term 

“pathogen-reduced mulch” is preferred. 

Response #1: Staff revised the definition of “active compost” by deleting the term, and by 

adding the preferred term “pathogen-reduced mulch” as recommended. 

Comment #2: PAR 1133.1 (c)(7): We recommend that the term “finished compost” includes 

unscreened finished compost which still includes oversized materials that will 

be screened out in final processing. Adding a new definition of “overs” is also 

recommended. 

SCAQMD IV-24 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Response #2: Staff revised the definition of “finished compost” by including “compost overs” 

as part of finished compost. The new term “compost overs” has been defined in 

the rule. 

Comment #3: PAR 1133.1 (c)(19): The definition of “woodwaste” is overly restrictive. Might 

woodwaste also include tree trunks, stumps, and limbs exceeding 2 inches in 

diameter? 

Response #3: The definition of “woodwaste” has been modified as recommended. 

Woodwaste now includes large wood materials of curbside or mixed greenwaste 

that is screened or unscreened, such as tree trimmings, branches, tree trunks, 

stumps, and limbs exceeding 2 inches in any dimension. 

Comment #4: PAR 1133.1 (d)(2): There is no provision in Title 14 that would prohibit the 

LEA from allowing an operator to hold materials up to 7 days “provided that the 

materials are not chipped or ground.” We believe that clause can be removed 

without changing the intent of the section. 

Response #4: That particular clause was removed. To effectively harmonize with Title 14, 

paragraph (d)(2) was modified to “... remove from the site within 48 hours of 

receipt, except observance of official federal and state holidays, or up to seven 

days maximum, with approval from the Local Enforcement Agency.” 

Comment #5: PAR 1133.1 (d)(3): The 24 hour holding time proposed to a biomass power 

generation facility might cause biomass plant operators to stop accepting 

greenwaste completely, further reducing markets for these materials. Biomass 

plants are currently exempt from Title 14 feedstock holding times. Might 

biomass power plants be permitted to hold chipped greenwaste longer than 24 

hours so long as the moisture content is below 30%? 

Response #5: Due to changes to paragraph (d)(2), this requirement is no longer needed and 

has been removed. 

Comment #6: PAR 1133.1 (d)(4): Although Construction, Demolition, and Inert (CDI) 

facilities primarily handle woodwaste, some do handle greenwaste. This section 

appears to open a loophole in the rule. In the interests of a level playing field, 

you may wish to require these facilities to handle greenwaste the same as other 

chip and grind facilities. You may also wish to expand the definition of 

woodwaste, per our Comment #3 of this section. 

Response #6: Paragraph (d)(4) was completely removed from the rule to avoid confusion and 

as it is already required by paragraph (d)(2) of the revised PAR 1133.1. For the 

definition of woodwaste, the reader is referred to Response #3 of this section. 

Comment #7: PAR 1133.1 (d)(6)(B) & (C): Strike the words “foodwaste” from here, as these 

facilities are not permitted to handle foodwaste unless they are also a permitted 

transfer station. 

Response #7: Staff removed the words as recommended. 

Comment #8: PAR 1133.1 (f)(3): We do not believe your intent is to limit this provision to 

curbside materials only. Please strike the word “curbside” from the first line. 

SCAQMD IV-25 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Response #8: This exemption is existing rule language and its modification is outside the 

scope of these amendments. Staff plans to continue to work on this chipping 

and grinding sector in the near future and may revisit this issue. 

Comment #9: PR 1133.3 (c)(7): The term defined here is no longer used in the rule. Is the 

definition needed? If so, is the reference to direct respirometry really a 

reference to the Solvita test? Since Solvita is already referenced, why change 

now? 

Response #9: This definition of “curing phase” has already been established in the District’s 

earlier Rule 1133.2 (co-composting rule). This term is still needed and used in 

the definition of “finished compost.” 

Comment #10: PR 1133.3 (d)(2)(A): Recent research by CalRecycle showed that overs were 

effective as a compost cap. When blended into the compost pile, overs reduce 

bulk density and increase penetration of air deep into the pile, helping maintain 

aerobic conditions. Overs typically contain beneficial microbes left over from 

the composting process, which helps inoculate the pile with and speeds 

decomposition. Please strongly consider allowing the use of overs as a compost 

cap material or provide your rationale as to why this should not be allowed. 

Response #10: The rule has been modified to allow the use of overs as a compost cap material 

by adding it to the new definition of “finished compost” (PR 1133.3 (c)(10)). 

Furthermore, the rule is now allowing screened or unscreened finished compost 

(including compost overs) as a cover material. 

Comment #11: PR 1133.3 (d)(2)(B): The word “subsequent” is confusing and probably 

unnecessary. 

Response #11: Staff removed the word as recommended. 

Comment #12: PR 1133.3 (d)(3): It would be helpful to define the method for calculating 

foodwaste percentage. What is the source of the 10% foodwaste figure? 

Foodwaste, even when source separated and not mixed with greenwaste, 

typically contains a high percentage of non-food materials, such as cardboard. 

This is recognized by entities such as the Climate Action Reserve, which 

requires foodwaste composters to actually measure the percentage of food in 

their waste streams in order to claim GHG credits. Even when collected 

separately from restaurants and institutions, the percentage of actual food in 

foodwaste is less than 100%. 

Response #12: Staff has revised the rule requirements with regard to foodwaste composting 

operations. The definition of “foodwaste” has been modified to address nonfood materials, and a threshold of annual foodwaste throughput on a facility 

basis is proposed. 

Some greenwaste composting facilities in the South Coast region currently 

accept foodwaste less than 10%, by weight, on a facility throughput basis, but 

actually more than 10% food scraps, by weight, are being composted in 

windrow recipes without the need of an add-on emission control device. There 

are only a few facilities handling this food material in the South Coast, but 

significant interest increases on this activity. Existing composting facilities use 

SCAQMD IV-26 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

foodwaste recipes of 1 part foodwaste to 2 or 4 parts greenwaste. Therefore, 

staff has set a new threshold of 5,000 tons per year of foodwaste throughput, 

above which an emission control device meeting at least 80% control efficiency 

for VOC and ammonia would be required for active phase piles or windrows 

containing foodwaste of 10 percent or more, by weight. By this revision, the 

rule proposes that up to 5,000 tons per year of foodwaste throughput be 

decomposed without an add-on control device. 

Public Comments 

Applicability

Comment #1: Please clarify applicability of PAR 1133.1 to chipping and grinding activities at 

multi-operation facilities that handle multiple incoming material streams with 

separate operating areas for chip and ship and composting operations within the 

same facility. 

Response #1: Staff clarified applicability of PAR 1133.1 to “chipping and grinding activities 

to produce materials other than active or finished compost, unless otherwise 

exempted.” Separate operations for chip and ship or chipping to produce 

biofuel or ADC within the same facility would be subject to the provisions of 

PAR 1133.1. However, chipping and grinding activities as part of composting 

operations to produce active or finished compost within the same facility would 

be subject to the provision of PR 1133.3(d)(1)(A). 

Comment #2: PAR 1133.1 does not list landfills or power plants for applicability, but they are 

given a time limit for utilization of materials in PAR 1133.1(d)(3). The new 

utilization time limits may cause power plants to delay acceptance of materials 

from greenwaste facilities, causing a backlog that would shut down operations. 

Response #2: The reader is referred to Response #4 of the CalRecycle Comments section and 

Response #9 of this section. 

Definitions

Comment #3: PR 1133.3(c)(12) adds a “per pile” requirement to the definition. We currently 

operate one of our greenwaste facilities with less than 20% manure, but may go 

over this minimum amount on a pile by pile basis. By changing the definition 

to a “per facility” basis allows greater flexibility in absorbing fluctuating input 

streams and lessens the need for stockpiling that will lower emissions. We feel 

that the “per pile” term should be changed to “per facility” in the definition of 

greenwaste composting and the word “waste” should be taken out of all the rule 

language altogether. 

Response #3: The definition of greenwaste composting with up to 20% manure, by volume, is 

to be consistent with District’s co-composting Rule 1133.2. Changing the 

definition to a “per facility” basis would conflict with Rule 1133.2. Under Rule 

1133.2, composting of greater than 20% manure, by volume would no longer be 

defined as greenwaste composting, but defined as co-composting and thus the 

operator would need to meet the requirements of Rule 1133.2. 

SCAQMD IV-27 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Comment #4: Residuals derived from food production and storage enterprises are typically not 

exclusively food waste. They typically include a lot of non-food, wrapping and 

container material (paper & plastic). For this reason when the rule says 10% 

foodwaste (e.g., 1133.3(d)(2)), it contains a significant portion (greater than 

50% by weight, depending on the source) of non-putrescible material. It is 

suggested that PR 1133.3 should delete “foodwaste” and define “food material” 

as the portion of the compostable material feedstock that is directly derived 

from vegetable or animal matter, which is consistent with the Title 14 term. 

The percent of food material will be determined for feedstock coming into the 

entire facility, not just one pile or windrow. 

Response #4: Staff re-defined the term “foodwaste” to be “any pre- or post-consumer food 

scraps collected from the food service industry, grocery stores, or residential 

food scrap collection.” The proposed threshold that would require installation 

of an emission control device has been modified to 5,000 tons per year of 

foodwaste throughput per facility and 10 percent foodwaste, by weight. Staff 

revised the rule language such that the annual throughput calculation may 

exclude any non-putrescible materials, non-compostable contaminants, and 

greenwaste that are separated before or after composting and shipped off-site 

for disposal, provided they are quantified and appropriate records are 

maintained. 

Comment #5: PAR 1133.1(c)(8) should exclude compostable food packaging materials which, 

being derived from plant fibers, are more like greenwaste than food. 

Response #5: As it pertains to chipping and grinding operations, staff does not feel that any 

modification is needed to this definition as the suggestion would require 

separation and characterization of the material which would be unnecessarily 

burdensome. 

Comment #6: Under PAR 1133.1, so-called “greenwaste” is not entirely composted of “leafy 

green” material, the putrescible portion, and the primary VOC producing 

component. For this reason, for the purpose of this rule, green material should 

be specifically defined as the VOC-producing portion of those materials as per 

Title 14. 

Response #6: Staff disagrees. The definition of greenwaste has been established in earlier 

District’s rules and modifying this definition could cause confusion to the 

readers. The large woody materials of greenwaste exceeding 2 inches in 

diameter are now considered woodwaste for the purpose of PAR 1133.1. 

Comment #7: Woody material, while compostable, typically is used in chipped or ground 

fashion to provide a very slow degrading “bulking agent” to more putrescible 

materials. Alternatively, it is used for “wood chips” or sent to biomass burn 

facilities for fuel. It is recommended that woody material portion of green 

material is considered wood material. 

Response #7: The reader is referred to Response #3 of the CalRecycle Comments section. 

Comment #8: Composting and compost are already defined in other regulations as time and 

temperature for pathogen reduction. It is recommended that the rule defines 

SCAQMD IV-28 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

“active compost” as in Title 14, and includes “compost overs” in the definition 

of “finished compost.” 

Response #8: Staff included temperature requirement as part of definition of “active compost” 

and included “compost overs” in the definition of “finished compost” as 

recommended. 

Greenwaste Processing and Stockpiling 

Comment #9: PAR 1133.1(d)(3) requires a landfill or “biomass power generation facility” to 

utilize the chipped or ground greenwaste within 24 hours of receipt. It appears 

that the rule considers a landfill application of ADC or erosion control the same 

as stockpiling greenwaste for fuel to produce energy. The applications are 

entirely different and the greenwaste at the plant does not remain on site or get 

buried, but is consumed in a timely manner. Attempting to operate with 24 

hours or less of inventory is not feasible or practiced anywhere in the biomass 

industry. In addition, the definition of “greenwaste” includes any organic 

material whereas Colmac’s greenwaste definition does not include grass, palm 

or succulents such as found at a landfill. 

Response #9: Staff removed that paragraph from the rule, and the same 48 hours or up to 

seven days maximum removal requirement would be applied to all facilities, 

with approval from the LEA. Staff also proposes an exemption for a biomass 

power generation facility or a facility processing material as a biomass fuel for a 

biomass power generation facility from the requirement of material removal 

within the allotted times, provided that the material temperature is maintained at 

below 122 degrees Fahrenheit or the moisture content is less than 30%. In 

addition, the definition of “non-curbside greenwaste” has been modified to 

include the large (exceeding 2 inches) woody material of greenwaste into the 

definition of “woodwaste.” 

Comment #10: PAR 1133.1(d)(4) should be revised to allow greater storage time for woody 

materials. 

Response #10: The reader is referred to Response #6 of the CalRecycle Comment section. 

Comment #11: PAR 1133.1(d)(2) and (d)(3) should be revised to mimic Title 14, Section 

17852(a)(10), which requires greenwaste to be “...removed from the site within 

48 hours of receipt.” Such a provision will allow facilities that do not operate 

24/7 adequate time to manage greenwaste, especially for materials received at 

the end of the regular business week. 

Response #11: Staff revised this requirement as recommended. 

Comment #12: For consistency, PAR 1133.1(d)(2)/(d)(3) and PR 1133.3(d)(1)(C) should 

contain the same processing and storage requirements. 

Response #12: Staff revised the processing and storage requirements such that they are 

consistent between the two rules. 

SCAQMD IV-29 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Foodwaste Limit

Comment #13: While I understand foodwaste can be a big contributor to VOCs, it is important 

to understand the foodwaste collection programs that are currently in place in 

various municipalities and institutions. 10% foodwaste by weight can be very 

deceiving. Foodwaste typically arrives in packages on pallets. As long as the 

packaging is organic and bio-degradable, no additional processing is required to 

remove contaminants from compost. In most cases, it is rare to receive clean 

pure foodwaste. Depending on the source (either pre- or post-consumer 

foodwaste), the percentage of non-food packaging can vary. A flat 10% 

maximum by weight is not conducive to the much needed foodwaste programs 

currently in effect. 

Response #13: The reader is referred to Response #12 of the CalRecycle Comments section. 

Emissions Control and Alternative

Comment #14: Forced aeration systems and windrow composting are two very different forms 

of composting and will require specifically defined language for each. While 

there are many common requirements, there are many differing methods in 

production that need to be considered. 

Response #14: Staff revised the rule language such that a specific composting technology (such 

as a force aeration system) is no longer required. However, the rule would still 

require an emission control device meeting at least 80% reductions in VOC and 

ammonia emissions if greater than 5,000 tons per year of foodwaste throughput 

is decomposed. This revision is to allow various technologies that may achieve 

the overall system control efficiency of at least 80%. 

Comment #15: PR 1133.3 should be revised to allow various technologies to achieve the 

overall system control efficiency of at least 80%. For example, Rule 1133.2 

provides a similar condition without specifying the control technology to be 

used employed. It is our experience that positive aeration systems and other 

technologies or approaches (e.g., ASP with pseudo-biofilter) could also be 

utilized to achieve the desired control efficiency. 

Response #15: The language has been revised to reflect this suggestion. 

Comment #16: PR 1133.3 would require approvals from the AQMD, CARB, as well as the US 

EPA to allow for adoption of alternative best management practices (BMPs) for 

emission reduction and alternative emission control methods by greenwaste 

composting operators. This will involve three levels of time-consuming 

government review. It is our opinion that the Executive Officer (EO) of the 

AQMD is sufficiently qualified to consider and approve alternative BMPs and 

alternative emission control methods. Therefore, it is our recommendation that 

the EO of the AQMD be the sole authority in the consideration and approval of 

alternative BMPs for emission reduction and alternative emission control 

methods proposed by greenwaste composting operators. 

Response #16: The reader is referred to Response #3 of the US EPA Comments section under 

the February 23rd Public Workshop Comments. As the rule will be submitted to 

SCAQMD IV-30 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

CARB and US EPA as a part of SIP, approval by all agencies is required to 

limit agency-specific discretion. In addition, this requirement is typical of other 

AQMD rules that include compliance alternatives. Staff will work to expedite 

such requests. 

Permitting/Offsets/BACT 

Comment #17: Compost producers need to have a better understanding of how the District staff 

plans to address Best Available Control Technology (BACT) for windrow 

composting vs. aerated static pile (ASP) composting for food material. 

Additionally, the percentage targets for BACT are not clearly defined. 

Response #17: Windrow composting does not require a permit. Finished compost cover is seen 

more as a BMP as opposed to a control technology, and thus does not require a 

permit. Depending on the circumstances, new and existing composting 

facilities modifying their operation may also be subject to New Source Review 

requirements of Regulation XIII, including BACT and offsets. ASP composting 

with appropriate emission control devices may be considered BACT. New 

facilities with control devices permitted would be required to provide offsets for 

their full potential to emit, i.e. maximum after control of emissions up to levels 

allowed by their permit. If they keep their permitted levels of controlled 

emissions below the 4 tons per year VOC threshold in Rule 1304(d), they will 

be exempt from the offset requirement. For existing facilities, no offsets would 

be required, provided no modification causes an increase in emissions. Even if 

the modification would result in an increase in emissions, the facility could take 

advantage of the small business exemption if its total emissions remain under 

the 4 tons per year threshold. Also, existing facilities are only required to offset 

the increase in emissions, or the amount in excess of the thresholds, if their premodification potential to emit was less than the amounts in Rule 1304(d). For 

purposes of this calculation, LEA permit limits on throughput will be 

considered to limit the source’s pre-modification potential to emit. Existing 

facilities required to install controls trigger the permit requirement, in which 

case they will be eligible for the offset exemption in Rule 1304(c)(4), provided 

there is no increase in maximum rating as established in the facility’s LEA 

permit. 

Comment #18: It is not clear if permitting would be required if you have a trammel screen or 

other pieces of equipment or control device that is listed in the permitting rules. 

Please clarify what constitutes triggering of an 1133.1 permit, based on 

equipment on any given site. 

Response #18: The AQMD permit requirements are specified in Rules 201 and 203, with 

permit exemptions specified in Rule 219. Generally, turning of a pile or 

windrow using DMV-registered motor vehicles does not require a permit. Onsite equipment, such as dedicated mobile grinders and screeners, are already 

subject to permit from the District or ARB, but that is for the equipment or 

engine emissions only, not composting emissions. If a pile is aerated, the 

mechanical aeration system and its associated emission control device would 

require a separate permit for each. 

SCAQMD IV-31 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

Exemptions

Comment #19: PAR 1133.1(f)(3) should apply to all greenwaste, instead of curbside 

greenwaste as drafted. 

Response #19: The reader is referred to Response #8 of the CalRecycle Comments section. 

Comment #20: As waste conversion technologies rapidly advance, greenwaste by itself or in 

combination with other organic materials may be composted at landfill sites via 

anaerobic processes in the near future. These landfill-based greenwaste 

composting operations will clearly not fit well with the regulatory framework of 

PR 1133.3. It is recommended that landfill-based anaerobic greenwaste 

composting operations be specifically exempt from PR 1133.3. 

Response #20: If anaerobic digestion is applied to greenwaste composting on its own (i.e., 

voluntarily by the facility operator), the composting would be exempt pursuant 

to PR 1133.3(g)(2), provided that an overall 80% control efficiency is 

demonstrated. 

Miscellaneous 

Comment #21: We want to be sure that we set a new precedent of socio-economic analysis for 

our industry, which is fundamentally based on the new sustainable economiesof-scope as applied to renewable carbon management. While we understand 

that this is beyond the scope of the current, prescribed methods of the District’s 

socio-economic analysis, we believe that we have a unique opportunity to use 

this rulemaking process to introduce an evolutionary change in this process. 

Response #21: As discussed at the working group meeting, such an analysis is beyond the 

scope of these proposed rules. 

Comment #22: We believe that the compost industry is unique, and strategically positioned, 

compared to any other industry, in helping society move to a sustainable, 

renewable carbon society. Since carbon is central to all life and economics, this 

industry is core to the emerging sustainable economy. For these reasons, the 

compost industry should be given new, and unique, analysis considerations. We 

suggest the District staff work with the compost industry closely to craft a new 

socio-economic analysis that adequately articulates and demonstrates the 

importance of this relatively small industry within the larger context of 

renewable carbon management. 

Response #22: Staff appreciates the environmental benefits that composting provides. 

However, the analysis requested is beyond the scope of this rule proposal. 

Socioeconomic Analysis

Comment #23: Relative to the analysis of impacts to the largest facility, a $240,000 annual 

compliance cost is very high. Would this not impact their viability? 

Response #23: The cost, which is driven by the cost of the water application BMP, is a worst 

case scenario. The facility has informed staff that this element of the rule is 

workable and has indicated that total water use may not be that high as the 

SCAQMD IV-32 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

increased water use will be minimized to the extent feasible by altering the 

water application timing. 

SCAQMD IV-33 July 2011 
PAR 1133.1 and PR 1133.3 Final Staff Report 

SCAQMD IV-34 July 2011 

Written comments were submitted by: 

Andrew Steckel, US EPA Region IX (2) 

Alex Krichevsky, Air Resources Board (ARB) 

Howard Levenson, Department of Resources Recycling and Recovery (CalRecycle) (2) 

Khalil M. Gharios, City of Los Angeles Solid Resource Processing/Construction Division (2) 

Neil Edgar, California Compost Coalition 

Hans Kernkamp, Riverside County Waste Management Department (2) 

Linda Novick, Harvest Power 

David Rothbart, Los Angeles County Sanitation Districts (2) 

Kevin Barnes, City of Bakersfield Solid Waste Division (2) 

David Tieu, Orange County Waste and Recycling 

Chuck Tobin, Burrtec Waste Industries 

Matt Cotton, Integrated Waste Management Consulting, LLC and on behalf of: 

Agromin; 

Aguinaga Green; 

Alameda County Waste Management Authority and Alameda County Source Reduction and 

Recycling Board as one Public Agency – StopWaste.org; 

Association of Compost Producers; 

Athens Services; 

American Organics; 

Burrtec Waste Industries; 

California Bio-Mass; 

California Against Waste; 

City of Bakersfield Solid Waste Division; 

Community Recycling and Resource Recovery; 

CR&R Incorporated; 

Harvest Power; 

Integrated Waste Management Consulting, LLC; and 

Recology 

Dan Noble, Association of Compost Producers (2) 

Paul Ryan, Inland Empire Disposal Association and on behalf of: 

California Refuse Recycling Council – Southern District; 

Inland Empire Disposal Association; 

Los Angeles County Waste Management Association; and 

Solid Waste Association of Orange County 

Brian Fuchs, W.L. Gore & Associates, Inc. 

Dean Johnson, American Organics 

James Russell Huffman, Colmac Energy, Inc.