SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT 

Final Staff Report 

Proposed Amended Rule 1150.1 - Control of Gaseous Emissions from Municipal Solid 

Waste Landfills 

April 2011 

Deputy Executive Officer 

Planning, Rule Development & Area Sources 

Elaine Chang, DrPH 

Assistant Deputy Executive Officer 

Planning, Rule Development & Area Sources 

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

Director of Strategic Initiatives 

Planning, Rule Development & Area Sources 

Jill Whynot 

AUTHOR: DAIRO MOODY - AIR QUALITY SPECIALIST 

REVIEWED BY: DAVID ONO - PROGRAM SUPERVISOR 

 NAVEEN BERRY – PLANNING AND RULES MANAGER 

 JOHN OLVERA - PRINCIPAL DEPUTY DISTRICT COUNSEL 

 LAUREN NEVITT - DEPUTY DISTRICT COUNSEL 

CONTRIBUTORS: DON HOPPS - AIR QUALITY SPECIALIST 

 ANDREW LEE, P.E. - PROGRAM SUPERVISOR 

 ATUL KANDHARI - AQ ENGINEER I 

 JEFFREY INABINET - AIR QUALITY SPECIALIST 
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 County 

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. 
Preface 

On August 10, 2010, the Draft Staff Report and Proposed Amended Rule (PAR) 

1150.1 - Control of Gaseous Emissions from Municipal Solid Waste Landfills were 

released for a thirty day public review for a September 10 Public Hearing. This Final 

Draft Staff Report contains the current staff proposal for PAR 1150.1 which is 

scheduled for a February 4, 2011 Public Hearing. The changes and clarifications made 

since the August release of the PAR 1150.1 materials are summarized below: 

 Removed subdivision (m) from the proposed amendment, which was included 

with the August 2010 proposal, and to address a California ballot measure 

regarding California Assembly Bill 32. This provision is no longer necessary. 

 Added comments received subsequent to the release of the Draft Staff Report 

in August 2010, summarized in the Public Comments section of the report. 

 Added comments received October 2010 from the California Air Resources 

Board (CARB), with responses from AQMD staff, summarized in the CARB 

Comments section of the report. Resultant changes to the proposed 

amendment include: 

- Updating the gas generation calculation methodology to reference the 

2006 Intergovernmental Panel on Climate Change (IPCC) Guidelines; 

and 

- Including additional exemption criteria based on the amount of wastein-place and the gas generation rate. 

 Updated compliance deadlines consistent with the December 2, 2010 CARB 

Regulatory Advisory, including: 

- Extending the compliance deadline to allow landfills to apply for and 

implement alternatives to this proposed amendment to April 1, 2011 

and July 1, 2011, respectively; and 

- Allowing for continued operation under previously approved 

Rule 1150.1 Compliance Plans until July 1, 2011, or until the owner or 

operator has received an approved revised Rule 1150.1 Compliance 

Plan; and 

- For Rule 1150.1 Compliance Plan revisions submitted on or before 

April 1, 2011 to meet the proposed amendment, allowing operation 

under the submittal if the plan approval is pending; and 

- Revising the annual report due date from March 31 to March 15. 

 Other minor administrative revisions and clarifications. 
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TABLE OF CONTENTS 

SECTION PAGE

EXECUTIVE SUMMARY ..................................................................................................1

BACKGROUND ..................................................................................................................2

Introduction ................................................................................................................................ 2

Regulatory History ..................................................................................................................... 3

Affected Industries ..................................................................................................................... 4

SUMMARY OF PROPOSED AMENDED RULE 1150.1 ................................................4

Overview ...................................................................................................................................... 4

Gas Collection and Control System Emission Control Requirements .................................. 5

Gas Collection and Control Systems ....................................................................................................... 5

Gas Control System Monitoring .......................................................................................................... 6

Gas Collection System Monitoring ...................................................................................................... 7

Surface and Subsurface Emission Standards and Monitoring .................................................................. 7

Instantaneous Surface Monitoring ....................................................................................................... 7

Integrated Surface Monitoring ............................................................................................................. 8

Combination Instantaneous and Integrated Surface Monitoring .......................................................... 8

Subsurface Refuse Boundary Monitoring ............................................................................................ 8

Operational Standards ............................................................................................................... 9

Gas Collection and Control Devices Continuous Operation .................................................................... 9

Components under Positive Pressure Monitoring .................................................................................... 9

Wellhead Negative Pressure and Monitoring .......................................................................................... 9

Alternatives ............................................................................................................................... 10

Recordkeeping and Reporting Requirements ........................................................................ 10

Administrative Changes ........................................................................................................... 11

Test Methods ......................................................................................................................................... 11

Incorporate 40 CFR, Part 63, Subpart AAAA by Reference ................................................................. 11

EMISSION REDUCTIONS .............................................................................................12

COMPARATIVE ANALYSIS ..........................................................................................12

SOCIOECONOMIC ASSESSMENT ...............................................................................15

CALIFORNIA ENVIRONMENTAL QUALITY ACT (CEQA) .....................................15

DRAFT FINDINGS UNDER CALIFORNIA HEALTH AND SAFETY CODE 

SECTION 40727 ...............................................................................................................15

COMMENTS AND RESPONSES ...................................................................................16

Public Comments ...................................................................................................................... 16

CARB Comments...................................................................................................................... 34

Other Comments ....................................................................................................................... 39

CONCLUSION..................................................................................................................39
Final Staff Report

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LIST OF TABLES 

PAGE

Table 1. MSW Landfills in the South Coast Basin ........................................................................................ 4

Table 2. Title V and Non Title V MSW Landfills by County ...................................................................... 12

Table 3. Comparison of MSW Regulations ................................................................................................. 14
EXECUTIVE SUMMARY 

Rule 1150.1 – Control of Gaseous Emission from Municipal Solid Waste 

(MSW) Landfills, was originally adopted by the South Coast Air Quality 

Management District (AQMD) Governing Board on April 5, 1985 to regulate 

emissions from active landfills. Landfills generate gaseous emissions that are 

comprised of several pollutants of concern, including Non-Methane Organic 

Compounds (NMOC), Volatile Organic Compounds (VOC), Toxic Air 

Contaminant (TAC) and odorous compounds, as well as greenhouse gases in 

the form of methane and carbon dioxide. The originally adopted Rule 1150.1 

and two subsequent administrative amendments in April 10, 1998 and March 

17, 2000 were focused on controlling the non-greenhouse gas components of 

landfill gas because of the contribution to criteria pollutant formation from 

VOC emissions, potential for public nuisance from odorous compounds, and 

potential detriment to public health from TAC emissions. Recent legislative 

activity has focused on controlling greenhouse gases, including the approval 

of the California Global Warming Solutions Act of 2006 (AB 32). Because 

the California Air Resources Board (CARB) has adopted an early action 

measure under AB32 aimed at controlling methane emissions from landfills, 

the primary purpose of this amendment is to incorporate the state requirements 

into the rule. The proposed amendment would also improve enforceability 

and streamline requirements by clarifying operation standards for control 

devices already installed, and by eliminating duplicate recordkeeping and 

redundant reporting. 

Elements of the proposed amendment fall into four categories: (1) 

incorporating CARB emission control requirements for Gas Collection and 

Control Systems (GCCS); (2) updating operation standards for control 

systems, including wellhead pressure gauge monitoring, to improve 

enforceability; (3) streamlining recordkeeping and reporting requirements; 

and, (4) revising rule language to address administrative corrections. 

First, the proposed amendment would add methane emissions control and 

lower the monitoring emissions limit for landfill control systems from 50 

ppmv to 25 ppmv to achieve equivalency to the CARB regulation for MSW 

landfills. CARB established the 25 ppmv limit based on data from South 

Coast Basin, which showed that the majority of landfills already comply with 

the lower limit and currently report values below the 25 ppmv limits based on 

currently required sampling. 

Second, the proposed amendment incorporates GCCS operational 

requirements identified in the CARB regulation. The proposed amendment 

requires control devices (e.g., compressors, internal combustion engines, and 

boilers) to be in full operation at all times, unless an alternative is requested 

and approved. The proposed amendment further requires that wellheads 
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operate under negative pressure at all times to ensure that landfill gases are not 

escaping into the atmosphere, and also requires enclosed flares and enclosed 

combustion devices to operate with installed automatic dampers, automatic 

shutdown devices, and flame arrestors. 

Third, the proposed amendment seeks to reconcile recordkeeping and 

reporting content and frequency with the requirements in the CARB 

regulation. While both the proposed amendment and CARB regulation have 

similar reporting requirements, they differ for annual reports. The proposed 

amendment consolidates the reporting of records into an annual reporting 

requirement to eliminate redundancy and minimize the burden on affected 

facilities. 

Finally, the proposed amendment also deletes outdated language and adds 

definitions, minor clarifications, and editorial corrections to improve clarity 

and enforceability. 

There is no expected significant cost increase associated with the proposed 

amendment because the collection and control equipment required by the 

CARB regulation to control methane have been installed and used by landfills 

within the District for over twenty years to control non-methane organic 

compounds. There may be administrative costs for processing requests for 

alternatives or changes to facility permits or plans, if needed. 

The proposed amendment has no potential to adversely impact air quality or 

any other environmental area and is therefore exempt from CEQA pursuant to 

state CEQA Guidelines §15061 (b)(3) – Review for Exemption. A Notice of 

Exemption will be prepared upon adoption of the proposed amendment and 

forwarded to the four county clerks for posting. 

BACKGROUND 

Introduction 

Municipal Solid Waste (MSW) landfills are classified to receive residential 

refuse that is collected separately from construction, hazardous and toxic 

waste. MSW is buried and compacted in the landfill where anaerobic 

decomposition generates large quantities of gas. This landfill gas, composed 

of near equal parts methane and carbon dioxide, also includes trace amounts 

(~ 1%) of non-methane organic compounds (NMOC), including volatile 

organic compounds (VOC), toxic air contaminants (TAC) and other odorous 

compounds. NMOC emissions contribute to ground level ozone formation, 

and represent a potential for public nuisance and detriment to public health, 

whereas methane is a greenhouse gas (GHG) that contributes to climate 

change, having a global warming potential 21 times greater than carbon 

dioxide. Methane is also known to be an explosive hazard and can damage 
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vegetation and crops. In California, MSW landfills are the second largest 

anthropogenic source of methane. 

Control of MSW landfill gases in the District is accomplished by the use of an 

active collection system. An active collection system uses a prime mover to 

draw a vacuum on a collection system to compress the landfill gases and 

deliver the gases to a combustion device. MSW landfills bury and compress 

refuse in layers separated by non-biodegradable barriers. Interlaced between 

these layers are a network of vertical gas wells and horizontal collector piping 

that constitutes the collection system upon which the prime mover creates a 

vacuum to deliver landfill gases at a steady rate to the combustion device. The 

combustion device can be an open or enclosed flare, although more efficient 

landfill gas combustors are used in the District, specifically, internal 

combustion engines (ICE), heaters and boilers. Energy from these devices is 

often used to generate electricity, representing a potential supplemental 

revenue stream. 

While the prime mover and the combustion device represent the control 

system, the collection system consists of the vertical wells and horizontal 

piping. Combined together, the control and collection systems constitute the 

vapor control system for MSW landfills. 

The proposed amendment requires control of both NMOC and methane 

emissions through use of appropriate control and collection systems, and 

defines associated source testing, sampling, monitoring, recordkeeping, and 

reporting of excess emission from control and collection devices at ground 

level as well as subsurface migration of landfill gases towards the landfill 

boundary. 

Regulatory History 

Rule 1150.1 was originally adopted by the AQMD Governing Board on 

April 5, 1985 and has since undergone two subsequent amendments on 

April 10, 1998 and March 17, 2000. The April 10, 1998 amendment merged 

the Rule 1150.1 requirements for active MSW landfills with the Rule 1150.2 

requirements for inactive MSW landfills. In 1988, EPA announced a decision 

to regulate landfills under the authority of the Clean Air Act (CAA) and 

proposed New Source Performance Standards (NSPS) in 1991, with 

promulgation in March 1996. The AQMD Governing Board approved an 

amendment to Rule 1150.1 to incorporate the NSPS Emissions Guidelines 

(EG) for existing landfills and NSPS emissions standards for new landfills in 

March 2000. As part of the same amendment, Sections 21140 and 20200 of 

Title 27 of the California Code of Regulations (CCR) were incorporated by 

reference into Rule 1150.1. Specifically, Section 21140 added requirements 

for closure and post-closure maintenance, and Section 20200 prohibited 

disposal of liquid and semi-liquid waste at Class III (municipal solid waste) 
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landfills in order to credit emission reductions under the state implementation 

plan. 

Affected Industries 

The rule amendment applies to existing MSW landfill facilities and any future 

MSW landfill facilities. 

There are currently 83 MSW landfill facilities in the District that would be 

subject to the proposed amendment. Of these facilities, 19 are currently active 

facilities or facilities that accept residential refuse, 64 landfills are inactive 

facilities which no longer accept refuse but still generate significant levels of 

landfill gas. Table 1, below, shows the breakdown of active MSW landfills 

and inactive MSW landfills in the District. 

Table 1. MSW Landfills in the South Coast Basin 

County Active 

Landfills 

Inactive 

Landfills Total 

Los Angeles 11 35 46 

Orange 2 13 15 

Riverside 3 9 12 

San Bernardino 3 7 10 

Total: 19 64 83 

Rule 1150.1 applies to both active and inactive landfills and while there is less 

activity at inactive landfill sites because they have been capped with layers of 

earth fill, they continue to have the potential to generate landfill gas emissions 

for a long period of time. The proposed amendment continues to focus on 

landfill gas control and collection methods and elimination of associated 

fugitive emissions. 

SUMMARY OF PROPOSED AMENDED RULE 1150.1 

Overview 

The proposed amendment is intended to incorporate the requirements of the 

CARB AB32 early action measure for MSW landfills (Title 17, CCR , Article 

4, Subarticle 6). While the primary purpose of the proposed amendment is to 

incorporate control of methane emissions into the rule, the proposed 

amendment is also aimed at improving enforceability and streamlining 

requirements by clarifying operation standards for control devices already 

installed and eliminating duplicate recordkeeping and redundant reporting. 
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Elements of the proposed amendment fall into the following four categories: 

1. Incorporating CARB emission control requirements for gas collection 

and control systems (GCCS). 

2. Updating operation standards for control devices, including wellhead 

pressure gauge monitoring, to improve enforceability. 

3. Streamlining recordkeeping and reporting requirements. 

4. Revising rule language for administrative changes. 

Gas Collection and Control System Emission Control Requirements 

The proposed amendment extends the emission limits of the current rule to 

include methane as prescribed by the CARB regulation. These limits are 

associated with controlled emission levels based on system control efficiency 

as well as monitoring of control system components and fugitive emission 

concentrations at the surface and subsurface to ensure system integrity. 

The proposed amendment requires instantaneous and integrated surface 

monitoring for MSW landfills consistent with the CARB regulation to check 

the gas collection system for malfunctions and leaks. Instantaneous 

monitoring measures instant surface emissions of total organic compounds 

(TOC), while integrated monitoring is done using instrument analysis of TOC 

over a 50,000 square foot grid and sampled for lab analysis for TAC. The 

proposed amendment continues to require subsurface refuse boundary 

monitoring, a process in which probes are placed around the perimeter of the 

landfill site at different depths to measure gas migration. Monthly samples are 

taken to determine if subsurface gases are approaching or going beyond the 

boundary of the landfill. 

Gas Collection and Control Systems 

Installation and operation of a GCCS has been required since the original 

adoption of Rule 1150.1. The proposed amendment incorporates control of 

methane emissions consistent with the CARB regulation, including 

requirements for design and emission limits. 

Although landfills within the District currently operate with existing GCCS, 

the proposed amendment incorporates the CARB requirements for design 

plans associated with site-specific gas collection and control systems that are 

not covered under a Permit to Construct or Permit to Operate; GCCS must be 

operated, maintained and expanded according to an approved design plan in 

the absence of an aforementioned permit. The proposed amendment applies 

the Professional Engineer certification requirements for design plans to also 

cover certification for any plan revisions. Finally, the proposed amendment 
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requires that design plans have a description of mitigation measures to be used 

in case there is release of methane or NMOC into the atmosphere during 

installation of landfill components or when there are repair work or system 

shutdowns of the GCCS. 

The proposed amendment requires that the GCCS be operated as an active gas 

collection system on a continuous basis, including situations where there is 

low flow, which may require operators to supplement landfill gases to 

maintain combustion in GCCS control devices or pursue an approved 

alternative. 

The conditional use of open flares has been added to the proposed 

amendment, even though there are very few such devices in the District. The 

proposed amendment restricts use of open flares by date of use. Any open 

flare operated before August 1, 2008 may operate until January 1, 2018. 

Operation of an open flare beyond 2018 will require the approval of the 

Executive Officer with documentation to support the request. The temporary 

use of open flares for repairs and maintenance while an enclosed flare is being 

repaired would also require approval from the Executive Officer. 

The proposed amendment requires enclosed combustion devices to achieve a 

methane destruction rate of 99% by weight in addition to reducing NMOC by 

at least 98% by weight and 3,000 ppmv for internal combustion engines at the 

outlet. Existing controls at MSW landfills in the District will be able to meet 

the new CARB requirement. During startup and shutdowns there must be 

enough supplemental fuel for the burners to prevent landfill gas venting to the 

atmosphere.

The proposed amendment requires GCCS under positive pressure to operate 

with no leaks exceeding 500 ppmv. Any leak discovered by the facility must 

be tagged and repaired in 10 days. 

Finally, the proposed amendment will require all wellheads to be under 

negative pressure at all times, except during wellhead rising and repair, during 

temporary shutdown of the GCCS, or after catastrophic events. 

Gas Control System Monitoring 

The proposed amendment to this rule includes a leak standard of 500 ppmv for 

components under positive pressure, which requires monitoring of all 

components used in the gas collection and control system, including blowers, 

compressors, connectors, fittings, flame arrestors, flanges, knock-out drums, 

pipes, sampling ports, and valves. If excess emission leaks are identified from 

these components, the proposed amendment requires repair and re-sampling 

consistent with the timeframes of the CARB regulation. 
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Gas Collection System Monitoring 

The operational efficiency of GCCS is determined by monitoring migration of 

underground landfill gases and liquids to the property boundary, and by 

monitoring leaks at the landfill surface. 

Consistent with the CARB regulation, the proposed amendment lowers the 

limit for integrated surface monitoring from 50 ppmv to 25 ppmv, and also 

adds an additional requirement for recording instantaneous monitoring results 

that exceed 200 ppmv TOC for data collection purposes. Landfills in the 

District are currently meeting the 25 ppmv level. 

The current version of Rule 1150.1 requires the repair of components that 

contribute to the exceedance of the aforementioned monitoring levels in 

accordance with prescribed timeframes. Following initial discovery, the 

GCCS must be repaired and re-monitored or re-sampled within 10 days. If the 

follow-up testing shows a second exceedance, another 10 days is allowed for 

repair and re-testing. Finally, if there is a third exceedance, corrective action 

is required to install and operate a replacement within 45 days from initial 

discovery. Although the CARB regulation provides for a final 120 days rather 

than 45 days from initial discovery, the District is proposing to maintain the 

current timeframes, based on historical implementation, and to avoid relaxing 

a SIP approved rule. 

Surface and Subsurface Emission Standards and Monitoring 

Current Rule 1150.1 not only requires both surface landfill sampling and 

monitoring, but also requires a subsurface refuse probe boundary sampling 

system. The subsurface monitoring is absent in the CARB regulation for 

landfills because another State agency has jurisdiction for subsurface 

monitoring (CalRecycle). Attachment A of the current rule contains the 

requirements for subsurface monitoring, with the intent towards design and 

installation consistent with CalRecycle subsurface boundary probe 

requirements. The proposed amendment maintains these requirements. 

Instantaneous Surface Monitoring 

Instantaneous monitoring is conducted by the MSW landfill owner or operator 

once a quarter (or every three months) by traversing a walking pattern of the 

grid in search of leaks that exceed the 500 ppmv emission standard. The 

CARB regulation requires measured methane emission leaks of 200 ppmv or 

greater be recorded for data collection purposes, but the emission standard that 

triggers corrective action is set higher at 500 ppmv. The 200 ppmv level for 

recording leaks has been added to the proposed amended rule. 
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Integrated Surface Monitoring 

CARB used SCAQMD data obtained from monitoring records to determine 

that the current emission standard in Rule 1150.1 could be reduced from 50 

ppmv to 25 ppmv. In order to maintain equivalent limits, the proposed 

amendment lowers the integrated surface monitoring limit to 25 ppmv. 

Integrated surface monitoring is conducted monthly and is intended to monitor 

the MSW landfill in greater detail than instantaneous surface monitoring 

provides. 

Two different methods for integrated surface monitoring have been used at 

MSW landfills. One method includes a monitoring apparatus that slowly 

ingests samples while the operator traverses a portion of the grid. The sample 

is contained in a tedlar bag, and the content is analyzed by an approved lab. If 

an exceedance of the integrated surface emission standard is determined, the 

operator is required to return to that portion of the grid and identify the 

specific area of concern. The second method for conducting integrated surface 

monitoring includes use of a flame ionization detector, calibrated to methane. 

AQMD staff has witnessed some hydrocarbon detection models using this 

method that not only detect emission leaks but also concurrently identify the 

exact location, so that the operator can readily initiate corrective action. 

Either method is acceptable for Rule 1150.1. 

Combination Instantaneous and Integrated Surface Monitoring 

Because the frequency for instantaneous monitoring is monthly and integrated 

monitoring is quarterly, there is an overlap in the two required events every 

three months. Rather than walk the same grid for two separate samplings 

during this overlapping period, county landfill operators in the District have 

reported conducting combined sampling without complication or significant 

procedural changes. Results are recorded separately on approved District 

forms and meet the intent of the current rule and proposed amendment. 

CARB is considering, either through regulation or on a case-by-case approval 

process, recognizing this practice through future guidance documents. 

Subsurface Refuse Boundary Monitoring 

The Subsurface Refuse Boundary Monitoring measures and detects 

underground lateral movement of landfill gases and liquids from the refuse 

footprint toward the landfill boundary line and onto neighboring property. 

Attachment A of the current version of Rule 1150.1 requires monthly samples 

that report less than 5 percent TOC from each probe. The proposed 

amendment maintains this requirement. 
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Operational Standards 

Gas Collection and Control Devices Continuous Operation 

Currently, Rule 1150.1 requires that control or treatment systems be operated 

at all times when collected gas is being routed to them. Conversely, current 

implementation of the rule allows for shutting down system components 

where collected gas is not being routed. The proposed amendment 

incorporates the requirement of the CARB regulation that calls for 

documentation of minimum flow through an approved alternative. As such, 

the proposed amendment requires continuous operation of the active 

collection system at all times, except where an alternative has been approved 

that establishes appropriate conditions to allow periods of interrupted 

operation. 

Components under Positive Pressure Monitoring 

Because it is necessary to pressurize components that deliver fuel in order to 

ensure a constant flow of landfill gases under pressure for combustion, the 

proposed amendment requires that all components that transfer landfill gases 

be monitored quarterly for leaks. Should a leak be detected at 500 ppmv or 

greater, the proposed amendment requires repairs be made in a timely manner 

through corrective action such as tagging the leak location and repairing the 

leak within 10 calendar days. Another reason for this proposed amendment is 

to make the requirements for compression and combustion equipment used in 

landfill gas generation to be comparable to the requirements subject to 

SCAQMD Rule 1173. 

Wellhead Negative Pressure and Monitoring 

The proposed amendment requires that wellheads be maintained under 

constant vacuum or negative pressure at all times. Wellheads are above 

ground components that are connected to a central header in the collection 

system for landfills. A negative pressure ensures that landfill gas is channeled 

through the collection system to the control devices and into the collection 

control system. 

Furthermore, the proposed amendment requires monthly monitoring of 

wellhead gauge pressure to ensure negative pressure is maintained. Positive 

pressure readings require corrective action within five days. If after the first 

five days the positive pressure persists, an additional 15 days are allowed for 

corrective action. Finally, all corrective measures including expansion must 

be completed and the gas collection system must be operational within 120 

days of when the first positive pressure reading was found. 
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Alternatives 

Currently, Rule 1150.1 allows facilities to request and obtain Districtapproved alternatives to specific sections of the rule. The proposed 

amendment continues this practice in a manner analogous to the CARB 

regulation, which allows for requested “Alternative Compliance Options.” 

Such collective “alternatives,” if approved, would be incorporated into a 

facility’s Rule 1150.1 Compliance Plan. In addition, where a plan revision is 

required to meet the proposed amendment, facilities are allowed to operate 

pursuant to a previously approved Rule 1150.1 Compliance Plan or, if plan 

approval is pending, the revised Rule 1150.1 Compliance Plan submitted on or 

before April 1, 2011.

Recordkeeping and Reporting Requirements 

The proposed amendment includes requirements from the CARB regulation 

that have been incorporated to improve consistency and minimize duplicative 

recordkeeping, while also allowing for the keeping of records in paper, 

electronic form, or other suitable format. In short, the proposed amendment 

updates the monitoring exceedance levels for recordkeeping consistent with 

the proposed amended emission limits, adds additional requirements for 

keeping and retaining records of source tests, periods of GCCS non-operation, 

component and surface monitoring results, exceedances and corrective 

actions, as well as the keeping of records associated with waste acceptance, 

current amount of waste in place, landfill areas excluded from collection 

systems, and landfill closure. 

The proposed amendment requires owners and operators to maintain original 

source test results and all annual performance tests results; if the combustion 

device is an open flare, all flare monitoring and records of periods when the 

pilot flame or flare flame is not present must also be maintained. 

The proposed amendment requires any results greater than 25 ppmv during 

integrated monitoring sampling and corrective actions taken to be recorded. 

The proposed amendment requires owners and operators to maintain records 

for instantaneous sampling for monitoring readings greater than 200 ppmv. 

Corrective action records continue to be required at the 500 ppmv level as 

identified in the current rule. 

While the current version of Rule 1150.1 requires recording of periods where 

the collection or control device system has not operated for longer than an 

hour, the amended version of the rule extends this requirement to include 

recording of installations of collection or control equipment, excavation of 

solid waste material, and construction activities that require exposing waste to 

the atmosphere. The proposed amendment further requires recording of a 

description of the activity, the affected area, the reason for the action, the start 
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and finish time and date, a list of the landfill components affected or replaced, 

and the mitigation measures taken. 

The proposed amendment requires owners and operators to maintain records 

of solid waste acceptance, solid waste acceptance rate, and the current amount 

of waste in place. Furthermore, owners and operators would be required to 

maintain all records of non-degradable waste acceptance, including the 

location, and amount deposited into any landfill area that excludes a collection 

system. 

The proposed amendment requires the owner and or operator to keep records 

of positive wellhead gauge pressure measurements, including the date, 

measurement, well identification, and corrective action taken. 

The proposed amendment adds additional recordkeeping requirements for 

Closure Reports, including the last day the landfill accepted solid waste, the 

project closure date, and the estimated waste-in-place. 

Administrative Changes 

In addition to minor rule language updates to remove outdated language and 

clarify definitions, the proposed amendment includes the following: 

Test Methods 

The CARB regulation considers VOC and methane interchangeable for 

control purposes since both are contained in the landfill gas stream and subject 

to destruction efficiency requirements. Therefore, the proposed amendment 

cites various source tests applicable for VOC and methane alone or in 

combination. The proposed amendment requires source testing of gas control 

devices for VOC and for methane using EPA Methods 25 and 18, as well as 

AQMD Method 25.1 (for VOC and methane), AQMD Method 25.3 (VOC and 

methane) and ASTM Method D1945 and D1946 (for methane only). 

Incorporate 40 CFR, Part 63, Subpart AAAA by Reference 

Subpart AAAA of the National Emissions Standard for Hazardous Air 

Pollutants (NESHAP), promulgated in 2003 by the EPA under authority of the 

Clean Air Act (CAA), section 112, is incorporated into the proposed amended 

rule by reference. The incorporation of 40 CFR, Part 63 Subpart AAAA of 

NESHAP requires all MSW Landfills that have bioreactors, and Title V 

facilities, to comply with this subpart by creating and using a Start-up, Shut 

down, and Malfunction Plan (SSMP). 
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EMISSION REDUCTIONS 

The proposed amendment is not expected to result in emission reductions. In 

order to maintain equivalency with the CARB landfill regulation the emission 

limit for integrated monitoring sampling was lowered from 50 to 25 ppmv. 

Compliance with the 25 ppmv has been achieved in practice with control and 

collection systems required at the 50 ppmv level and therefore no actual 

emission reductions are achieved or claimed. 

COMPARATIVE ANALYSIS 

As required by Health and Safety Code Section 40727.2, the purpose of this 

analysis is to identify and compare any other AQMD or federal regulations 

that apply to the same equipment or source type. 

The existing and the proposed amended Rule 1150.1 are not in conflict with 

National Emissions Standard for Hazardous Air Pollutants (NESHAP) 40 

CFR Part 63 Subpart AAAA. On January 16, 2003 the US EPA promulgated 

the landfill NESHAP under the authority of CAA, section 112. The Landfill 

NESHAP applies to major sources (Title V facilities) and contains the same 

requirements as landfill emissions guidelines and Landfill NSPS, but add 

requirements for startup, shutdown, and malfunction (SSM), operating 

conditions, and deviations for out-of-bound monitoring parameters (see 

Table 3). Table 2 below shows a breakdown of Title V and Non Title V 

MSW landfills by county in which they operate. 

Table 2. Title V and Non Title V MSW Landfills by County 

County Title V Non Title V Total 

Los Angeles 17 29 46 

Orange 6 9 15 

Riverside 3 9 12 

San Bernardino 7 3 10 

Total: 33 50 83 

The NESHAP Landfill regulation makes reference to a guidance document 

that explains how to prepare a startup, shutdown, and malfunction plan (SSM 

Plan) for municipal solid waste landfills. The guidance document requires 

those landfills that have a collection and control system or who must install 

one, to prepare a SSM Plan. This subpart addresses concerns with the 

malfunction of landfill gas collection, control, and treatment systems and 

requires landfills to document the reasons causing the malfunction, corrective 

measures taken, and measures taken to prevent future problems. 
Final Staff Report

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In the District there are thirty-three Title V MSW landfills facilities (under 

Standard Industrial Classification Code 4953, 1600, 9711; NAICS Code 

562212) and fifty facilities that are not required to have Title V permits. The 

thirty-three Title V facilities are required by Part 70 and 71 of the Clean Air 

act to have a SSM Plan and are thereby required to follow the procedures in 

the plan during startups, shutdowns, and malfunction. Table 3−Comparison of 

MSW Regulations−has been prepared to show a comparison between the

proposed amended Rule 1150.1, guidance document, and NESHAP 

Regulation Subpart AAAA. 
Final Staff Report

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Table 3. Comparison of MSW Regulations 

Category Proposed Amended Rule 

1150.1 U.S.EPA CTG USEPA NESHAP 40 CFR 63 Sub-Part AAAA 

Purpose To prevent public nuisance 

and possible detriment to 

public health 

The document is intended 

to explain how to prepare a 

startup, shutdown, 

malfunction plan for MSW 

facilities 

Establishes National 

Emission Standards for 

Hazardous Air Pollutants 

for existing and new 

municipal solid waste 

landfills 

Applicability Rule 1150.1 applies to each 

active and inactive MSW 

landfill 

Owner and operators of 

MSW landfills who need to 

comply with NESHAP 

requirement for startup 

shutdown malfunction plans 

Applies to MSW landfills 

that are a major source >= 

10 tons/yr HAP or 25 ton/yr 

combo HAP or facility> 

2.5MM Mg design capacity 

Averaging Provisions None None None 

Units  ppmv 

 Percent by volume 

None None 

Operating Parameters Uses current source test 

results and conditions of 

S/T as operation 

parameters and operation 

limits 

For equipment associated 

with collection and control 

of landfills gas regulation 

requires records of 

standard operation 

procedure to prevent 

emissions to atmosphere 

The NESHAP refers to 

guidance document for 

records and reporting for 

control and collection 

equipment operation 

parameters 

Method to Determine VOC U.S.EPA Method 21 

U.S. EPA Method 18 

Not Identified Subpart AAAA refers to 

Subpart WWW for US EPA 

Method 21 and Method 18 

Capture Efficiency U.S.EPA Method 25 

U.S. EPA Method 18 

Not Identified Subpart AAAA refers to 

Subpart WWW for US EPA 

Method 25 and Method 18 

Control Device Efficiency U.S.EPA Method 25 &18 Not Identified U.S.EPA Method 25 & 18 

Work Practices  Boundary monitoring 

 Surface and subsurface 

sampling and monitoring 

 Collection system 

pressure monitoring 

Not Identified Active landfills must comply 

with subpart WWW 

sampling and monitoring 

requirements 

Monitoring Done by monthly sample 

collection and testing for 

pressure, temperature TOC 

and TAC 

Not Identified Regulation refers to subpart 

WWW for monitoring 

requirements 

Reporting Annual source test report, 

annual report, when needed 

closure & decommissioning 

report 

Document outlines the 

content, for required 

records to be contained in 

report and form, and 

frequency of required 

reports 

Regulation refers to 

Guidance document for 

SSMP for landfill control 

and collection systems 

reporting requirements 

Recordkeeping Rule requires records for: 

all control equipment 

testing, results from 

monthly and quarterly 

monitoring and sampling, 

combustion device 

temperatures readings, flow 

records from control 

devices 

Document details the form 

and content of the SSM 

plan and the data from the 

gas control system and the 

gas treatment system to be 

recorded. Requires a 

description of each process 

and occurrence and 

duration of each 

malfunction. The action 

taken to correct malfunction 

and any deviation from the 

plan. 

Comprehensive records 

required annually to support 

compliance with NESHAP 
Final Staff Report

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SOCIOECONOMIC ASSESSMENT 

The proposed amendment is mostly administrative and will coincide with the 

implementation of CARB regulations for MSW landfills which affect landfills 

in the South Coast Basin. The proposed amendment is not expected to result 

in adverse socioeconomic or environmental impacts since the proposed rule 

does not significantly affect air quality or emissions limitations, and does not 

impose new controls. However, facilities may have additional administrative 

costs if they choose to pursue or amend an existing Rule 1150.1 Compliance 

Plan to request alternatives to the new requirements of the proposed 

amendment. However, by including state and federal requirements in Rule 

1150.1 and implementing the CARB regulation locally, these costs should be 

offset through the minimization of duplicate recordkeeping and reporting. 

CALIFORNIA ENVIRONMENTAL QUALITY ACT (CEQA) 

The SCAQMD has reviewed the proposed project pursuant to the CEQA 

Guidelines §15002 (k)(1), the first step of a three-step process for deciding 

which document to prepare for a project subject to CEQA. Staff has prepared 

a Notice of Exemption (NOE) for Proposed Amended Rule (PAR) 1150.1 for 

the following reasons: 1) the proposed amendments incorporate state 

regulations adopted by the California Air Resources Board (CARB) that 

specify requirements for municipal solid waste landfills; and 2) collection and 

control equipment required by CARB’s regulation has already been installed 

and is currently in operation at all affected South Coast Basin municipal solid 

waste landfills since the adoption of the current rule on April 5, 1985. Since 

the proposed project is approving established regulations and will not require 

new equipment that would generate new adverse environmental impacts, it 

can be seen with certainty that the proposed project has no potential to 

adversely impact air quality or any other environmental area and is exempt 

from CEQA pursuant to state CEQA Guidelines §15061 (b)(3) – Review for 

Exemption. The Notice of Exemption will be filed with the county clerks of 

Los Angeles, Orange, Riverside and San Bernardino counties immediately 

following the adoption of the proposed project. 

DRAFT FINDINGS UNDER CALIFORNIA HEALTH AND SAFETY CODE 

SECTION 40727 

Health and Safety Code Section 40727 requires that prior to adopting, 

amending or repealing rules, the AQMD Governing Board shall make findings 

of necessity, authority, clarity, consistency, non-duplication and reference, 

based on relevant information presented at the hearing. The draft findings are 

as follows: 
Final Staff Report

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Necessity: The AQMD Governing Board has determined that a need exists to 

amend Rule 1150.1 - Control of Gaseous Emissions from Municipal Solid 

Waste Landfills, to improve consistency with CARB’s Regulation to Reduce 

Methane Emissions from Municipal Solid Waste Landfills in terms of 

monitoring limits and recording and reporting requirements and to implement 

the requirements of 40 CFR, Part 63 Subpart AAAA – National Emissions 

Standards for Hazardous Air Pollutants: Municipal Solid Waste Landfills. 

Authority: The AQMD obtains its authority to adopt, amend or repeal rules 

and regulations from California Health and Safety Code Sections 39002, 

39650, 40000, 40001, 40440, 40441, 40463, 40702, and 40725 through 

40728, 41508, 41700, and 42300. 

Clarity: Rule 1150.1 - Control of Gaseous Emissions from Municipal Solid 

Waste Landfills, as proposed to be amended, is written or displayed so that its 

meaning can be easily understood by the persons directly affected by it. 

Consistency: Proposed Amended Rule 1150.1 - Control of Gaseous

Emissions from Municipal Waste Landfills is in harmony with, and not in 

conflict with or contradictory to, existing statutes, court decisions, or federal 

or state regulations. 

Non Duplication: Rule 1150.1 - Control of Gaseous Emissions from 

Municipal Solid Waste Landfills, as proposed to be amended, does not impose 

the same requirements as any existing state or federal regulations, and the 

amendments are necessary and proper to execute the powers and duties 

granted to, and imposed upon, the AQMD. The proposed amendment 

consolidates existing state and federal requirements. 

Reference: This regulation would implement, interpret or make specific the 

provisions of: Health and Safety Code Sections 40001 (rules to achieve 

ambient air quality standards), 40440(a) and (c) (rules to carry out the Air 

Quality Management Plan and rules which are also cost-effective and 

efficient), 40702 (rules to execute duties necessary to preserve original intent 

of rule), 40910 et seq., (California Clean Air Act), and Federal Clean Air Act 

§111 (New Source Performance Standards). 

COMMENTS AND RESPONSES 

Public Comments 

A public workshop was held on June 25, 2010 in which approximately 15 

people attended. Participants provided comments at the meeting and three 

followed up letters were received. The following section summarizes the 

comments received at the meeting and staff’s responses. 
Final Staff Report

- 17 -

Comment #1 

Will implementation of this AB32 regulation require additional CARB 

oversight or delegation to the District with respect to inspections and other 

enforcement activities? Full delegation to the District is preferred. 

Response 

Local air districts that currently have regulations for landfills or adopt a rule 

can enter into a Memorandum of Understanding (MOU) with CARB to be 

responsible for implementing the rule for the state. SCAQMD is proposing to 

amend Rule 1150.1 to include all State requirements so as to minimize the 

recordkeeping and reporting burden associated with reporting to two agencies. 

CARB staff will likely review and audit implementation activities by air 

districts. 

Comment #2 

What are the expected emission reductions from PAR 1150.1? 

Response 

The proposed amendment to Rule 1150.1 is not expected to result in emission 

reductions. Although the proposed integrated monitoring limit represents a 

reduction from 50 to 25 ppmv because records have shown monitoring results 

consistently below 25 ppmv in the majority of landfills, the proposed 

amendment would only reflect current emission levels rather than result in 

actual reductions. 

Comment #3 

Because AB32 is currently being challenged under a ballot measure in 

November, it may be prudent to delay consideration of PAR 1150.1 until 

December. 

Response 

Consideration of PAR 1150.1 has been delayed until after the November 2010 

election. 

Comment #4 

Will landfills be allowed to maintain existing approved alternatives under 

PAR 1150.1, or will they need to re-apply for them?

Response 

Compliance plans would need to be updated for Title V facilities when their 5-

year renewal cycle occurs, to reflect the most recent rule requirements. If the 
Final Staff Report

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facility does not need to request an approved alternative because of changes to 

the rule, then no action would be required. To add to an existing compliance 

plan, an application would be necessary. 

Comment #5 

PAR 1150.1 refers to different plans, including a design compliance plan and 

an alternative compliance option. What are the differences between the 

different plan types, and if there is no difference, can PAR 1150.1 be modified 

to use consistent terminology? 

Response 

Staff agrees and the rule language has been changed to remove the term 

“Compliance” when referring to the Design Plan. In addition, the CARB 

regulation reference to use of the term “Alternative Compliance Option” is 

equivalent to the term “alternative” in the proposed amendment. 

Comment #6 

Previously, Rule 1150.1 required extensive work in developing a set of 

alternative work practices that both the District and the landfills could agree 

to. Under PAR 1150.1, will the District support a collaborative effort to 

expedite development of additional alternatives? 

Response 

Yes, staff will work with landfill operators to streamline the alternative 

approval and Rule 1150.1 Compliance Plan process. 

Comment #7 

The translation from source test results to parameter requirements in PAR 

1150.1 should be clarified further. 

Response 

In response to this comment, staff has improved references from subparagraph 

(d)(1)(C) which require an operational need for source testing for control 

devices and refers to paragraph (e)(7) monitoring requirements which call for 

monitoring of parameters used in source tests. 

Comment #8 

There is a concern about the requirement for continuous operations, while 

AQMD anticipates breakdowns; paragraph (d)(14) requires continuous 

operations. We suggest wording that would comply with CARB Rule 

95464(e). Proposed paragraph (d)(14) anticipates that SCAQMD’s 
Final Staff Report

- 19 -

breakdown provision is broad enough to cover the intent of the CARB 

provisions. However, we have at least one situation at a landfill where annual 

preventative maintenance on an Edison substation causes us to shut our 

system down for about eight hours. This is technically not a breakdown, and 

under the new language would cause us to now get a variance. 

Response 

The proposed amendment allows for use of approved alternatives. This 

situation is appropriate for case-by-case review and evaluation, and may also 

be more appropriately included as permit conditions, since maintenance, and 

particularly scheduled maintenance, is dependent on the type of control used. 

This would not require a variance. 

Comment #9 

The PAR and staff report indicate that the regulation intends to use the 

Title 27 probe requirements, but the rule was not adequately changed to do 

this, and requires compliance with both requirements. The probes should 

meet Title 27 requirement, if applicable, or otherwise meet AQMD 

requirements. 

Response 

Paragraph (d)(9) of the proposed amendment has been revised to require all 

active and inactive landfills that have not been given written approval by 

CalRecycle for installation of subsurface refuse boundary sampling probes to 

be required to design and install according to Attachment A sections 1.1. 

Comment #10 

It is our understanding that the CARB regulation allows for 120 days to install 

and operate new wells whereas Rule 1150.1 and PAR 1150.1 only allow 45 

days, which is a financial burden with little to no air quality benefit, as the 

wells may not be fully compliant during initial startup. It is recommended that 

the time period be extended to 120 days for consistency and to reduce 

compliance costs. 

Response 

The current rule requirements under subdivision (e) allow for 45 days so 

changing to 120 days would be a relaxation of the current SIP approved rule. 

However, subparagraph (i)(2) of the proposed amendment provides for use of 

approved alternatives for landfills that can demonstrate sufficient additional 

need. 
Final Staff Report

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Comment #11 

The requirement under clause (d)(1)(C)(iv)(IV) for sufficient flow of 

commercial natural gas is impractical to implement and would represent a 

significant cost impact. 

Response 

Staff has reviewed this comment relative to the CARB regulatory requirement 

and removed this requirement from the proposed amendment. 

Comment #12 

Use of the term “vapor-tight integrity” seems to be contradictory with the 

nature of landfills. Landfills by nature release vapors. This term should be 

reviewed and revised. 

Response 

The term “vapor tight integrity” was removed from the proposed amended 

language and replaced with revised language to meet the intent of this 

comment. 

Comment #13 

Subparagraphs (e)(4)(B) and (e)(4)(C) require 10 days and 45 days, 

respectively, to address wellhead pressure repairs and new well installations. 

The first should be modified to indicate that the 10-day clock is measured 

from the time of the last repair rather than the first measurement, and the 

second should be modified from 45 days to 120 days.

Response 

Changes have been made to the proposed amended rule so that it is 

comparable to the CARB regulatory convention of 5 days from the first 

positive pressure reading; if the problem is not corrected, 15 days from the 

first positive pressure reading, and if not resolved, 120 days from the first 

positive pressure reading. 

Comment #14 

The purpose of PAR 1150.1 should be updated to note that, with respect to 

control of methane that the purpose is to support implementation of AB32 

rather than extend the purpose of the original Rule 1150.1, which is to address 

public nuisance and exposure to NMOC and TACs. 
Final Staff Report

- 21 -

Response 

Staff has revised the proposed section of rule language to meet the intent of 

this comment to segregate the inclusion of methane emissions control from 

NMOC and TACs. 

Comment #15 

The term (f)(2)(C) “closure” may need to be defined for clarity. 

Response 

Staff has reviewed the proposed language and understands that the comment is 

intended to distinguish the difference between “closed” and “inactive.” 

Because use of the term “closure” is in context with adjoining rule language 

(e.g., “closure report”), staff did not make this change in the rule. 

Comment #16 

Please see rule language in Rule 1110.2 related to source testing and 

consideration of violation notices, and consider using the same language for 

PAR 1150.1. 

Response 

Staff agrees, and has revised the proposed amended language to incorporate 

language similar to Rule 1110.2. 

Comment #17 

Term “insignificant risk” in paragraph (k)(3) is too broad and should be either 

defined or narrowed in scope. 

Response 

Staff has reviewed the proposed amendment language relative to use of the 

term “insignificant risk”. Because the criteria identified in paragraph (k)(3) 

relates to pre-existing regulatory thresholds that are deemed “significant”, staff 

has changed the language in the proposed amendment to refer to “less than 

significant” rather than “insignificant”. This clarification is not expected to 

change how this provision is implemented. 

Comment #18 

Staff should change (d)(16) to allow operation of the gas system to “prevent” 

fire in addition to “extinguishing” a fire. Preventing a fire is more critical than 

extinguishing the fire. We believe this addition falls within the intent of this 

section. 
Final Staff Report

- 22 -

Response 

The intent of subparagraph (d)(16)(B) is to allow exceptions for turning off 

control and collection devices in the event of catastrophic events, in order to 

make repairs as part of a temporary shutdown. Staff understands the 

commenter’s request to replace “extinguishing” with “preventing”; however, 

staff believes that doing so would weaken the intent of the section, as 

compared to the same provisions in the CARB regulation. Therefore no 

change was made in the section. 

Comment #19 

The issue of operating parameters in (d)(1)(C)(ii)(IV) [The enclosed flare shall 

be operated within the parameter ranges established during the initial or most 

recent source test] and (d)(1)(C)(iv)(VI) needs to be clarified. 

Response 

The requirements of clause (d)(1)(C)(ii) apply to enclosed flares while clause 

(d)(1)(C)(iv) applies to enclosed control devices other than flares. Both 

require operation within source test parameters. 

Comment #20 

In (d)(1)(C)(i), add the Lean Burning Engine requirements due to crossreferences. Revising this section allows (d)(1)(C)(iii)(I) to be eliminated. 

Response 

Staff has reviewed the clause referring to Lean Burn Engines. Clause 

(d)(1)(C)(i) lists general requirements for all control devices, of which lean 

burn ICEs are included. The specific requirements for lean burn engines 

would be appropriate in clause (d)(1)(C)(iv) requirements for “enclosed 

combustor or other than a flare”. 

Comment #21 

In (e)(1) we would recommend using Title 27 requirements, or retaining the 

existing timeline requirements. It is not clear why the requirement on the 

second exceedance would be reduced from 10 days to 7 days. 

Response 

Staff agrees and has revised the proposed amended language back to 10 days 

for the first occurrence, 10 days for the second occurrence and 45 days for the 

third. 
Final Staff Report

- 23 -

Comment #22 

The allowance for annual monitoring in (e)(3) differs from 95469(a)(1)(c) by 

leaving out the word “area.” 

Response 

The allowance in PAR 1150.1 (e)(3) applies to closed and inactive landfills, 

whereas Section 95469 of the CARB regulation applies to closed and inactive 

landfills as well as closed and inactive sections (areas) of active landfills. This 

was not extended to active landfills in the proposed amendment to allow a 

review by the Executive Officer of documentation for areas or sections that are 

closed or inactive in an active landfill. This review would be handled as part 

of an approved alternative under the proposed amendment. 

Comment #23 

The timeline in (e)(4) should be made consistent with the CARB timeline, as 

the time periods (10 days versus 15 days) should be counted from the prior 

monitoring and not from the initial monitoring. 

Response 

The five days for the initial exceedance has been changed to 10 calendar days 

and the second exceedance has been changed from 10 days to 20 days from 

the initial exceedance. This is comparable to the CARB convention of 10 

days for the first occurrence and 10 days for the second from the last day of 

the first occurrence of exceedance. See also response to Comment #13. 

Comment #24 

PAR 1150.1 subparagraph (e)(7)(C) should include the allowance for 

monitoring power plant components prior to a scheduled outage. 

Response

The wording in subparagraph (d)(13)(A) was moved to subparagraph 

(e)(7)(C), maintaining the intent to allow for monitoring during scheduled 

outages and scheduled maintenance. 

The following include additional comments that were received subsequent to the 

public workshop: 

Comment #25 

The gas probe monitoring requirements starting in paragraph (d)(9) are 

redundant for facilities permitted by CalRecycle as a Solid Waste Landfill. 

Recent changes to Title 27 require solid waste facilities to design and 
Final Staff Report

- 24 -

implement an approved gas monitoring plan. These plans were transmitted to 

SCAQMD prior to approval. With this change in Title 27, the requirements in 

Rule 1150.1 are unnecessary and may cause future issues. Suggest relying on 

Title 27 approved monitoring plans for permitted facilities and PAR 1150.1 

compliance for all other facilities not currently regulated under Title 27 with 

respect to landfill gas migration. 

Response 

Rule 1150.1 currently defers to Title 27 in the case of design and installation 

of subsurface probes. Specifically, the rule requires all active and inactive 

landfills that have not been given written approval by CalRecycle for 

installation of subsurface refuse boundary sampling probes to design and 

install such probes in accordance with Attachment A (sections 1.1 through 1.6 

of the proposed amendment). 

Comment #26 

The corrective action timeframe in Rule 1150.1 is inconsistent with Title 27 

and the federal Subtitle D requirements for landfills. Title 27 requires 

immediate verbal notification, written 7 day notification describing measures 

taken or planned to protect human health and the environment and a corrective 

action plan within 60 days outlining the corrective actions taken to resolve the 

probe exceedance. 

Response 

The proposed amendment has been updated to reflect the intent of your 

comment. While Title 27 allows five days from the first exceedance rather 

than 10 days under the proposed amendment, and a total of 60 days rather than 

65 days under the proposed amendment, it is clear that meeting the 

requirements of Title 27 would not conflict with the requirements of the 

proposed amendment. 

Comment #27 

CARB requires quarterly integrated and instantaneous monitoring; however, 

Rule 1150.1 requires monthly integrated and quarterly instantaneous 

monitoring. Suggest that the Proposed 1150.1 be revised to be consistent with 

CARB. Not aware of the benefit for monthly integrated monitoring. Data 

should be presented to demonstrate how the additional cost to conduct this 

monitoring is justified. 

Response 

The integrated monitoring sampling provides a snapshot of the state of 

compliance of the entire collection system and is more helpful than the 

instantaneous surface monitoring which is done quarterly. This is a benefit to 
Final Staff Report

- 25 -

public health by checking on a monthly basis that the system is in compliance. 

Making the requested change would be a relaxation of the SIP approved 

version of the rule, so this change was not made. 

Comment #28 

The timeline for corrective action for any exceedance as a result of integrated, 

instantaneous or probe monitoring is inconsistent with CARB. Rule 1150.1 

requires that the wellhead will be expanded within 45 days from the third 

exceedance, instead of 120 days from the third exceedance (CARB). It has 

been very difficult over the years to expand the system within 45 days from 

the third exceedance. There are numerous variables that influence the 

performance of the gas collection system. Adding a well to the gas collection 

system is more than simply drilling a new well. It involves connecting it to the 

gas collection system, bringing it online slowly to avoid increasing the well 

temperature, and readjusting nearby wells. Given the nature of solid waste 

disposal, the location of a new well or wells is not an absolute science; quite 

to the contrary, it is more of an educated guess. A new well may or may not 

produce the methane predicted. In this case additional wells are needed. 

Response 

Staff recognizes that problems arise in wellhead replacement and repairs but 

that not all replacements and repairs require 120 days or more for compliance. 

Also this change would be a rule relaxation of a SIP-approved rule. 

However, similar to the CARB’s regulation, MSW landfills can pursue an 

approved alternative, especially in situations where procurement of parts may 

be a continuing issue. 

Comment #29 

Sec. (d)(9) and (10), (e)(1) and Attachment A 1.0 - suggest modifying the 

perimeter probe requirement in this PAR to allow CCR Title 27 to take 

precedence and eliminate conflicts between this rule and the state regulation. 

Response 

Rule 1150.1 currently defers to Title 27 for design and installation of 

subsurface probes. Section 1.1 in Attachment A defers to CalRecycle 

requirements for the installation and design of subsurface probes compared to 

compliance with sections 1.1.1 to 1.1.4 (whenever possible). Paragraph (d)(9) 

of the proposed amendment requires all active and inactive landfills that have 

not been given written approval by CalRecycle for installation of subsurface 

refuse boundary sampling probes to design and install such probes in 

accordance with sections 1.1 through 1.4 of Attachment A to the proposed 

amended rule. 
Final Staff Report

- 26 -

Comment #30 

Sec. (d)(16) - We do not agree with the proposed requirement as it applies to 

older, smaller sites located in arid and semi-arid regions to keep negative 

pressure on wellheads. Many of these sites have several wells turned off due 

to poor gas quality and can show pressure is a function of temperature and 

barometric pressure. The wells have 0.01 to 0.05 inches of water column. We 

want to maintain the wells in case of wet years, which cause an increase in gas 

production. This section should consider the increased potential for landfill 

fires caused by the continuous, and perhaps unnecessary, introduction of 

vacuum to the refuse prism creating an oxygen rich environment. 

Response 

The CARB regulation for MSW landfills contains the same negative pressure 

requirements for all wellheads, so SCAQMD staff cannot omit this 

requirement. Similar to the allowances provided for in the CARB regulation, 

subparagraph (i)(2) of the proposed amendment provides for use of an 

approved alternative for landfills that can demonstrate sufficient need. 

Comment #31 

Sec. (e)(3)(A) and (f)(1) - These sections require that records be maintained at 

the landfill site. Most of the sites we operate are remote un-manned sites. We 

recommend some language that allows the records to be kept at the “agency 

headquarters.” 

Response 

This has been re-worded in the proposed amendment. Please see paragraph 

(f)(1). 

Comment #32 

Section (f)(1)(D) - Remedial action should not be required for exceedances of 

200 ppmv as stated in this section. This should be removed as remedial action 

under Proposed Amended Rule 1150.1. The CARB rule only requires action 

for exceedances of 500 ppmv. 

Response 

Staff has revised the proposed amended language. 

Comment #33 

Section (k) - We strongly suggest that subdivision (k) include exemptions 

similar to the CARB rule based on the landfill size, such as the 450,000 tons 

of waste-in-place threshold set forth in the CARB rule. 
Final Staff Report

- 27 -

Response 

While the CARB regulation uses a 450,000 ton threshold to determine if a Gas 

Collection and Control System is required, current Rule 1150.1 historically 

has not had an exemption threshold and to incorporate one would be a 

relaxation of a SIP-approved rule. 

Comment #34 

SCAQMD should hold more public workshops so that many of these 

comments and suggestions may be discussed in more detail. The schedule for 

adoption of this rule should occur later to allow for those detailed discussions 

to occur. 

Response 

Staff has met with individual commenters subsequent to the public workshop, 

based on expressed interest and have incorporated the results of these 

discussions into the proposed amendment. 

The following include additional comments that were received subsequent to the 

release of the draft staff report: 

Comment #35 

We wish to clarify that the PAR will become effective 1/1/11, per Section (g). 

The State has indicated that the regulation implementation date could be 

pushed back to July 2011. Will SCAQMD also push back the date for 

implementing the proposed changes to Rule 1150.1? 

Response 

The District has incorporated into the amended rule an effective compliance 

date of July 1, 2011. This date would apply to facilities that need to amend 

their compliance plans in order to comply with the amended rule, provided 

that applications for alternatives be submitted April 1, 2011 for approval prior 

to the July 1, 2011 compliance date. 

Comment #36 

We appreciate the added language of Section (m) that recognizes Proposition 

23, however, we are concerned that if Proposition 23 passes, there could be 

legal challenges staying the suspension of AB32, leaving the landfill industry 

in “limbo” until AB32 is actually suspended [Section (m) is triggered only if 

AB32 is suspended]. Therefore, we would propose the following alternate 

language: 
Final Staff Report

- 28 -

If the state ballot measure to suspend AB32 is approved, the provisions of 

this rule shall not become effective until it is found that AB32 is 

suspended, at which time the provisions of this rule will revert to the 

March 17, 2000 version. If the state ballot measure is approved and its 

implementation stayed by legal challenges, the provisions of this rule shall 

only come into effect if it is found that the ballot measure is not valid for 

the provisions of Article 4, Subarticle 6, sections 95460 to 95476, title 17, 

of the California Code of Regulations (Methane Emissions from Municipal 

Solid Waste Landfills). 

Response 

Subdivision (m) has been removed from the proposed amendment following 

the November 2010 election and the resultant “no” vote outcome on 

Proposition 23. 

Comment #37 

Section (d)(9) requires compliance with Section 1.1 through 1.6 of Attachment 

A if subsurface probes have not been issued prior written approval. Most 

landfills have gotten their existing probe systems grandfathered in as part the 

Compliance Plans issued under the 1998 Rule 1150.1 modifications. As the 

SCAQMD is aware, many of the landfills operating in the SCAB have gone 

through extensive upgrades to their probe systems as a result of the new Title 

27 provisions that have been overseen by CalRecycle. Many of us have not 

yet updated our Compliance Plans to reflect these changes, nor received 

written approval from the SCAQMD. As currently written, the PAR 1150.1 

would require all the landfill owner/operators who have upgraded, or are in the 

process of upgrading their probe systems to now have to reapply to the 

SCAQMD and demonstrate compliance with the provisions of Section 1.1 

through 1.6 of Attachment A. 

The approval process undertaken by CalRecycle for new or modified probe 

systems is a case-by-case determination based upon the underlying geology of 

the landfill. The resultant probe construction and placement may or may not 

be fully consistent with the requirements outlined in Attachment A, but the 

overall system will be more protective of preventing landfill gas migration 

than following the more general approach outlined in Attachment A. 

Although the “response to comments” in the draft Staff Report seems to 

indicate that the Title 27 probe systems take precedence over the SCAQMD 

design approach, the actual rule language specifies clearly that both Title 27 

and PAR 1150. 1, Section 1.1 through 1.6 of Attachment A, must be met. We 

suggest the following amended language Section 1.1 in Attachment A to 

ensure that the Title 27 subsurface probe approval process under CalRecovery 

would be the primary authority for probe system approval: 
Final Staff Report

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It is the District’s intent that subsurface refuse boundary probes required 

by paragraph (d)(9) of Rule 1150.1 be designed and installed in such a 

manner as to comply with the requirements set forth in Title 27, as 

administered by of CalRecycle (whenever possible), if applicable. If the 

Title 27 probe requirements are not applicable, then and meet the 

requirements set forth in Sections 1.1.1 through 1.1.4. Irrespective of Title 

27 probe applicability, the Executive Officer may make a finding that 

more stringent probe requirements are necessary. 

Response 

The proposed amendment is not intended to modify the intent of existing rule 

language relative to Attachment A and subsurface refuse boundary sampling 

probes. Historically, upgrades to the subsurface monitoring system, whether 

driven by Title 27 or otherwise, have been addressed via the Rule 1150.1 

Compliance Plan through approved alternatives. The District intends to 

continue this practice, and has not proposed any changes to existing rule 

language in this regard. While the District understands the efforts landfills 

have undertaken to comply with the provisions of Title 27, because the focus 

of CalRecycle is not identical to that of the District with respect to gas 

migration, the District intends to continue to reserve the option to review and 

evaluate subsurface gas migration monitoring systems with respect to air 

quality impacts, as provided for in existing rule language. 

Comment #38 

In Section (d), it is still not clear when a Design Plan is needed or existing 

plans need to be updated. The language seems to indicate that if we have 

valid permits for the gas collection and control systems and meet the 

requirements of Section (d)(1)(A) through (d)(1)(C), then a Design Plan is not 

needed. Is this interpretation correct? However, what happens if we are 

expanding the gas system or control system requiring new or modified 

permits? Section (d)(3) seems to indicate that in this situation, we would need 

to amend “the existing design plan to include any necessary updates or 

addenda.” If our interpretation of (d)(3) is correct, as stated above, we would 

object to this approach. Design plans have never been part of the Rule 1150.1 

process and would represent additional administrative work that is 

unnecessary. The SCAQMD has successfully relied on permits and 

alternative Compliance Plans to ensure systems are in place to meet the 

stringent surface gas standards, and in fact by your own writings, the industry 

has already been mostly been in compliance with the new 25 ppm integrated 

threshold. We see no reason to deviate from this successful approach. 

Therefore, to address this concern, we would suggest the following 

amendment to Section (d)(3): 
Final Staff Report

- 30 -

Any owner or operator of existing gas collection and gas control systems 

who modifies those systems to meet the requirements of this rule shall 

submit for approval to the Executive Officer an amendment of any existing 

design plans to include any necessary updates or addenda, unless the 

proposed system will be issued a valid Permit to Construct or Permit to 

Operate that meets the requirements of subparagraphs (d)(1)(A) through 

(d)(1)(C). 

This approach would now be consistent with the language in Section (d)(1). 

Response 

If a design plan was not previously required under Rule 1150.1, updates to a 

design plan would not be required; rather any updates subject to the proposed 

amendment would be addressed through the landfill permit or compliance plan 

as appropriate. 

Comment #39 

We would like to clarify that the natural gas or propane flow referred to in 

Section (d)(1)(C)(ii)(III) is to the pilot, not the burner. 

Response 

The wording for subclause (d)(1)(C)(ii)(III) is identical to the CARB 

regulation and the District intends to maintain equivalency with both the 

language and the intent. See also response to CARB comment #4.

Comment #40 

In Section (d)(1)(C)(ii)(IV), the parameter of importance (for enclosed flares) 

is temperature, which already has limits contained within Rule 1150.1. 

Therefore, we suggest the following minor modification to the language: 

The operating parameters to be monitored are specified in paragraph 

(e)(7)(A)(i).

Response 

Paragraph (e)(7) refers to subparagraph (e)(7)(A), which includes the 

requirements associated with (e)(7)(A)(i) and (e)(7)(A)(ii); because it 

accomplishes the same intent as the comment, no change is proposed. 

Comment #41 

Section (d)(1)(C)(iv) is still problematic. As currently written, it could be read 

that engines must meet the 99% destruction efficiency. We suggest the 

following amendment to (iv)(I): 
Final Staff Report

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The gas control device shall achieve a methane destruction efficiency of at 

least 99% by weight, or if a Llean burn combustion engines, shall instead 

reduce the outlet .... 

Section (d)(1)(C)(iv)(II) should be removed because it is repetitive and once 

again could indicate that engines need to meet the 99% destruction efficiency. 

Section (d)(1)(C)(iv)(V) is too broad. We suggest the following rule language 

amendment: 

The operating parameters to be monitored, for flares, are specified in 

paragraph (e)(7)(A)(i), and for all other devices, in paragraph (e)(7)(B).

Response 

Subparagraph (d)(1)(C )(iv) is the same as in the CARB regulation for gas 

control devices other than flares. In order to maintain equivalency and intent 

no changes are proposed. Staff agrees that subparagraph (d)(1)(C)(iv)(II) is 

redundant and has revised the proposed amendment accordingly. Finally, staff 

believes that the proposed alternative language of the last part of this comment 

is not needed to improve the intent of the rule and therefore no changes are 

proposed. 

Comment #42 

We need to discuss the temperature requirements that are established in 

Sections (e)(7) and (f)(1)(L)(i). When Rule 1150.1 was revised in 1998, we 

received the temperature exception language for boilers, but not for other 

devices such as engines and turbines. The temperature requirements should 

only apply to flares to establish a surrogate for destruction efficiency of toxics 

and VOCs. Other combustion devices achieve high destruction efficiency by 

other means that are not easily measured. Do we need a rule change to reflect 

this, or can this simply by handled in the Compliance Plans as an alternative? 

Response 

Staff believes that this situation is best handled as an alternative in an 

approved compliance plan, due to the case-by-case specificity of the 

assessment. 

Comment #43 

In Section (f)(4), is the “responsible company official” the same as in Title V? 

Realize that every landfill impacted by Rule 1150.1 is not necessarily a Title V 

facility. 
Final Staff Report

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Response 

The proposed language “responsible company official” has been changed to 

“responsible official” to reflect the intent of this comment and maintain 

equivalency with the CARB regulatory language. 

Comment #44 

Section (f)(1)(H), requires recordkeeping for instances of construction where 

solid waste material is exposed. This broad language would include 

installation of gas systems, for instance, that are normally exempt. We believe 

that this recordkeeping is unnecessary and actually satisfied by other 

SCAQMD requirements or regulations. For example, permits to construct for 

gas system installations have requirements for minimizing odors and 

emissions associated with these activities. Other categories of construction 

that expose solid waste are covered under Rule 1150, requiring a detailed plan. 

This extra level of recordkeeping is unnecessary and not consistent with the 

streamlining efforts SCAQMD is trying to achieve. We therefore recommend 

the following language to address these concerns: 

During construction that requires exposing solid waste material to the 

atmosphere, the following records are required unless adequate 

mitigation is prescribed in a Permit to Construct and/or operate, or a Rule 

1150 Excavation Management Plan.

Response 

While permit conditions may cover the same requirements for records as a 

regulation or rule, this does not require landfills to maintain two sets of 

records, rather the same set of records would satisfy both conditions. 

Inclusion of recordkeeping requirements as part of rule making ensures 

consistency for affected sources, including permitted and new sources. 

Comment #45 

Does the current version of Rule 1150.1 that has been deemed to be equivalent 

to the Federal EG regulation, not the NSPS standards for new landfills, as 

described on page 5? The new landfill NSPS standards are enforced by 

AQMD separately from Rule 1150.1. 

Response 

Although the District has incorporated the provisions of the NSPS into Rule 

1150.1, federal regulations may be cited separately in enforcement matters 

where applicable. 
Final Staff Report

- 33 -

Comment #46 

On Page 8 the required destruction efficiencies are described for enclosed 

combustion devices, however, it is not indicated that these requirements do 

not apply to engines that have a separate requirement of 3,000 ppm. 

Response 

This section was updated to indicate that internal combustion engines have a 

separate requirement of 3,000 ppmv. 

Comment #47 

Page 7 incorrectly describes wellhead pressure monitoring as an “updated 

standard” when it was incorporated from the CARB rule. 

Response 

The wellhead pressure monitoring relative to the current Rule 1150.1 is an 

update. 

Comment #48 

The description of integrated monitoring on the middle of page 7 is incorrect, 

integrated monitoring is done using instrument analysis of TOC over a 50,000 

square foot grid, and selected grids are sampled for a lab analysis of TAC. 

Response 

The wording was changed to reflect instrument analysis for TOC and lab 

analysis of TAC. 

Comment #49 

Monitoring should be described as quarterly, not every 3 months (page 9). 

Response 

The staff report correctly meets the intent of the comment by describing the 

period as quarterly. The parenthetical descriptor of “or every 3 months” 

identifies a quarter as three months and is neither regulatory language nor 

conflicting language. 

Comment #50 

The method of hydrocarbon monitoring with location identification described 

on page 10 is under development and is not available. 
Final Staff Report

- 34 -

Response 

No changes will be made to this section since the purpose of describing the 

hydrocarbon monitoring with location identification is not a regulatory 

requirement, but serves to illustrate methods that have been witnessed and 

may be used in the future. 

Comment #51 

We are not aware of AQMD pre-approved forms for surface gas data, and are 

already monitoring using an AQMD approved instrument that integrates 

surface gas monitoring. Is a Guidance document (as described) being

developed by the AQMD? 

Response 

The wording “pre-approved” was changed to “approved” and refers to 

subdivision (f) that requires that forms, whether electronic or paper media, be 

approved by the Executive Officer. 

Comment #52 

The last paragraph on page 11 should be revised to represent the rule’s 

timeline requirement for remediation of a positive pressure well to initiate 

action within 5 days, re-monitor within 15 days of the first exceedance, and if 

still in exceedance expand the gas collection system with any new wells being 

placed in operation within 120 days of the first exceedance. 

Response 

The staff report has been updated to replace the phrase “an additional 20 days” 

with the 5/15 day requirement to address the intent of this comment and for 

consistency with CARB’s regulation. 

CARB Comments 

The following summarizes the comments received from CARB (letter dated 

October 7, 2010) following release of the draft staff report and proposed 

amended rule. 

Comment #1 

General: On June 17, 2010, the Office of Administrative Law approved 

California Code of Regulations, title 17, article 4, subarticle 6, sections 95460 

to 95476, Methane Emissions from Municipal Solid Waste Landfills 

(“regulation”) and filed it with the Secretary of State. The regulation became 

effective on the same day. ARB staff understands that SCAQMD is planning 

to implement and enforce the regulation by amending Rule 1150.1 to make it 
Final Staff Report

- 35 -

equivalent to, or more stringent than the regulation. We would like to make 

SCAQMD aware that it must enter into a Memorandum of Understanding 

with ARB regarding the implementation and enforcement of the regulation. 

Response 

The District is aware of the Memorandum of Understanding obligation and 

will enter into the appropriate agreement as needed. 

Comment #2 

Section (a) (Purpose): This section appears to isolate the reduction of methane 

emissions as a secondary benefit of proposed amended Rule. We suggest 

rewording this section as follows: “The purpose of this rule is to reduce 

methane (a greenhouse gas), non-methane organic compounds (NMOC), 

volatile organic compound (VOC), and toxic air contaminant (TAC) 

emissions from.........to prevent public nuisance and possible detriment to 

public health caused by exposure to such emissions.” 

Response 

Staff believes the currently proposed language identifies control of methane 

emissions as an additional benefit, not a secondary benefit. The currently 

proposed language was intended to address a public comment centered on the 

nature of methane as compared to the historically controlled pollutants. 

See also response to Public Comment #14. 

Comment #3 

Section (d)(1)(A): (Active Landfill Design and Operation Requirements): 

This section requires the use of one of the equations in 40 CFR, Part 60, 

§60.755(a)(1) to determine the maximum gas generation flow rate. These 

equations are not equivalent because of their inability to allow for potential 

methane generation capacity variation on a year-to-year basis over the lifetime 

of the landfill, which is very important to the results. For equivalency, 

§95471(e) of ARB’s landfill regulation (Test Methods and Procedures) 

requires the use of the 2006 Intergovernmental Panel on Climate Change 

Guidelines for National Greenhouse Gas Inventories, Chapter 3 (or, “IPCC 

model”), using a landfill gas capture factor of 75 percent to determine the 

captured gas expected flow rate from the total gas generation estimates of the 

IPCC model. The main advantages of the IPCC model is that it allows the 

user to: adjust the potential methane generation capacity on a year to year 

basis; use specific degradation parameters by waste type; use time delays other 

than six months; and correct for methane oxidation. The landfill gas tool 

developed by ARB staff is an acceptable method to use to compute the 

captured gas expected flow rate and is based on the IPCC model. 
Final Staff Report

- 36 -

Response 

Although the calculation models associated with subdivision (d)(1)(A) apply 

only to facilities that do not have gas collection and control systems and may 

not apply to locations within the District, staff agrees that reference to the 

updated equations is warranted for consistency and the proposed language has 

been revised accordingly. 

Comment #4 

Section (d)(1)(C)(ii)(III) (Active Landfill Design and Operation 

Requirements): This section reads as follows, “During restart or startup, an 

enclosed flare shall have sufficient flow of propane or commercial natural gas 

to the burners ......” For clarity, the phrase “to the burners” should be 

replaced with “to the pilot light.” 

Response 

Although the District agrees with the intent of this comment, the wording of 

subclause (d)(1)(C)(ii)(III) was incorporated from CARB language [Article 4, 

subarticle 6 §95464, title 17, CCR (b)(2)(A)(3)]. The District would also like 

to maintain consistency with the adopted regulatory language and therefore 

has communicated consistent intent within the staff report while maintaining 

the regulatory language as adopted by CARB. 

Comment #5 

Section (g) (Active Landfill Compliance Schedule): This section incorrectly 

refers to the date “July 1, 2001.” The correct date should be “July 1, 2011.” 

Response 

The proposed amendment has been revised accordingly. 

Comment #6 

Section (h)(2) (Inactive Landfill Requirements): This section requires owners 

and operators of inactive MSW landfills without gas collection and control 

systems to install controls based on: surface methane concentrations 

exceeding 500 ppmv at any location on the landfill surface, the results of a 

screening questionnaire and solid waste air quality assessment test, and upon 

formal notification from the Executive Officer. This section is not equivalent 

to § 95463(b) of the regulation which states that owners and operators of all 

MSW landfills having 450,000 tons of waste-in-place or greater and a landfill 

gas heat input capacity of greater than or equal to 3.0 MMBtu/hr must either 

install a gas collection and control system, or conduct a surface test to 

demonstrate that there is no surface methane leaks of 200 ppmv or greater on 

the landfill surface after four consecutive monitoring periods. 
Final Staff Report

- 37 -

For equivalency, section (h)(2)(B) of this section should be revised as follows: 

“Submit the following data and/or meet the required action in paragraph 

(h)(1): 

(iv) Calculate the landfill gas heat input capacity pursuant to § 95471(b) of 

California Code of Regulations, title 17, article 4, subarticle 6 and submit 

a Landfill Gas Heat Input Capacity Report to the Executive Officer. If the 

landfill gas heat input capacity is greater than or equal to 3.0 MMBtu/hr, 

the owner or operator must comply with paragraph (h)(3) or conduct a 

surface test to demonstrate that there is no surface methane leaks of 200 

ppmv or greater on the landfill surface after four consecutive monitoring 

periods. 

(h)(3) upon notification by the Executive Officer that a landfill gas 

collection and control system and/or..........comply with paragraph 

(h)(1).” 

Response 

The proposed language has been revised to change the surface test criteria 

from 500 ppmv to 200 ppmv in order to maintain equivalent stringency with 

the CARB regulation. It should be noted that paragraph (h)(2) is not expected 

to apply to any facility located within the District, as evidenced by current 

district records and CARB’s current inventory of inactive landfills, because 

there are no known inactive landfills located in the South Coast Basin without 

a collection system. This is due in large part to the current rule. As 

historically implemented, landfills that did not meet the less than 500 ppmv 

surface monitoring criteria (now proposed for revision to less than 200 ppmv) 

were required to submit information through the screening questionnaire and 

the solid waste air quality assessment test, pursuant to the Health & Safety 

Code subpart 41805.5, in order to determine the appropriate type of gas 

collection and control system that the landfill would be required to install. In 

no case has an inactive landfill been deemed to be exempted from installation 

of collection or control systems except as provided by provisions of 

subdivision (k). (See also response to CARB comment #7). 

It is staff’s position that the revised proposed amendment is at least equivalent 

in stringency, and perhaps more stringent to subpart 95463(b) of the CARB 

regulation because the revised proposed amendment, would not exempt 

landfills based solely on the amount of waste-in-place and gas generated rate, 

but also relies on additional criteria, including an evaluation of toxic air 

contaminant and public nuisance risk. 
Final Staff Report

- 38 -

Comment #7 

Section (k) Exemptions: This section temporarily exempts a MSW landfill 

from all or any portion of the requirements of the Rule based on toxic air 

contaminant emissions and health risk analysis, proximity to sensitive 

receptors, emission migration, and other criteria, but does not significantly 

consider these exemptions from a greenhouse gas perspective. This section is 

not equivalent to § 95463 (Determination for Installing a Gas Collection and 

Control System) of the regulation and should be revised as follows: 

“An MSW landfill may be temporarily exempt from all or any portion of 

the requirements of this rule if...... 

(1) The MSW landfill complies with....... 

(5) The MSW landfill is closed or inactive and has a landfill gas heat 

input capacity of less than 3.0 MMBtu/hr. and submits a Waste-in-Place 

Report and all instantaneous surface monitoring records to the Executive 

Officer, or; 

(6) The MSW landfill has 450,000 tons of waste-in-place or greater and a 

landfill gas heat input capacity greater than or equal to 3.0 MMBtu/hr and 

the owner or operator demonstrates to the satisfaction of the Executive 

Officer that after four consecutive quarterly instantaneous monitoring 

periods there is no surface methane leak exceeding 200 ppmv. If the 

landfill is active the heat capacity must be re-calculated annually. 

(A) If the MSW landfill is closed or inactive and passes the surface 

demonstration test; the owner or operator must submit a Waste-in-Place 

report and all instantaneous surface monitoring records to the Executive 

Officer.” 

Response 

Staff understands CARB’s comment to focus on the requirement to install gas 

collection and control systems based on a minimum gas generation rate. As 

such, staff has incorporated language into the proposed amendment to limit 

the exemption to the requirements of paragraphs (d) and (e) related to 

installation of such controls and maintain consistency with the state minimum 

threshold levels by allowing for exemptions based on the above commented 

criteria of quantity of waste in place, minimum gas heat input generated, and 

instantaneous surface monitoring results. 

Comment #8 

Attachment A: We recommend that Figure 2 be revised to more accurately 

reflect a walking pattern based on 25 foot spacing. In addition, Figure 3 does 

not provide a column for recording methane concentrations. We recommend 
Final Staff Report

- 39 -

adding a column for tracking surface methane concentrations for both 

integrated and instantaneous surface monitoring. 

Response 

Both Figure 2 (Typical Landfill Walk Pattern for a 50,000 square foot Grid) 

and Figure 3 (Quality Control Sheet) of Attachment A to the proposed 

amendment are illustrative examples for landfill owners and operators to refer 

to in the development of appropriate walking patterns and recordkeeping 

forms specific to individual locations. Because of the variability of landscapes 

and operational practices, it is neither expected, nor the practice under the 

current rule, for landfill owners and operators to follow the exact walking 

pattern depicted by Figure 2, or the exact replica of the Quality Control Sheet 

of Figure 3. However, to provide additional clarification, the title of Figure 3 

has been updated to include the word “Typical” for consistency. Staff 

believes that Figure 2 and Figure 3 meet the intent to provide illustrative 

examples rather than define prescriptive requirements, and provide landfill 

owners and operators the flexibility to record the information and data needed 

to demonstrate compliance with the proposed amendment. 

Other Comments 

In addition to the above comments, staff has received and reviewed numerous 

comments identifying typographical and grammatical errors, as well as crossreferencing updates. Staff appreciates the input and has updated the proposed 

rule language as appropriate. 

CONCLUSION 

If approved, the proposed amendment to Rule 1150.1 will incorporate existing 

federal requirements and the requirements of the CARB regulation adopted to 

implement the AB 32 early action measure addressing methane emissions 

from municipal solid waste landfills. There is no expected significant cost 

increase associated with the proposed amendment because the collection and 

control equipment required by the CARB regulation have been installed and 

used by landfills within the District for more than twenty years to control nonmethane organic compounds. This amendment consolidates requirements and 

will reduce redundant recordkeeping and reporting. The only potential cost 

associated with this amendment are some administrative costs that may occur 

if an approved alternative is pursued or a change to facility permits or plans is 

needed