Revised Proposed June 18, 2009

RULE 4311 FLARES (Adopted June 20, 2002; Amended June 15, 2006; Amended [Rule 

adoption Date]) 

1.0 Purpose 

The purpose of this rule is to l Limit the emissions of volatile organic compounds (VOC),

and oxides of nitrogen (NOx), and sulfur oxides (SOx) from the operation of flares. 

2.0 Applicability 

This rule is applicable to operations involving the use of flares. 

3.0 Definitions 

3.1 Air-Assisted Flare: a combustion device where forced air is injected to promote 

turbulence for mixing and to provide combustion air. 

3.2 Air Pollution Control Officer (APCO): as defined in Rule 1020 (Definitions). 

3.3 Air Resources Board (ARB or CARB): as defined in Rule 1020 (Definitions). 

3.4 British Thermal Unit (Btu): the amount of heat required to raise the temperature of 

one pound of water from 59oF to 60oF at one atmosphere. 

3.5 Calendar Day: any day starting at twelve o’clock AM and ending at 11:59 PM. 

3.63.4 Coanda Effect Flare: A flare in which the high pressure flare gas flows along a 

curved surface inspirating air into the gas to promote combustion. 

3.73.5 Emergency: any situation or a condition arising from a sudden and reasonably 

unforeseeable and unpreventable event beyond the control of the operator. Examples 

include, but are not limited to, not preventable equipment failure, natural disaster, act 

of war or terrorism, or external power curtailment, excluding a power curtailment 

due to an interruptible power service agreement from a utility. A flaring event due to 

improperly designed equipment, lack of preventative maintenance, careless or 

improper operation, operator error or willful misconduct does not quality as an 

emergency. An emergency situation requires immediate corrective action to restore 

safe operation. A planned flaring event shall not be considered as an emergency. 

3.83.6 Enclosed Flare: a flare composed of multiple gas burners that are grouped in an 

enclosure, and are staged to operate at a wide range of flow rates. 

3.9 EPA: United States Environmental Protection Agency. 

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3.10 Feasible: Capable of being accomplished in a successful manner within a reasonable 

period of time, taking into account economic, environmental, legal, social, and 

technological factors. 

3.11.7 Flare: a direct combustion device in which air and all combustible gases react at the 

burner with the objective of complete and instantaneous oxidation of the combustible 

gases. Flares are used either continuously or intermittently and are not equipped with 

devices for fuel-air mix control or for temperature control. 

 

3.12 Flare Event: any intentional or unintentional combustion of vent gas in a flare. The 

flare event ends when the flow velocity drops below 0.12 feet per second or when the 

operator can demonstrate that no more vent gas was combusted based upon the 

monitoring records of the flare water seal level and/or other parameters as approved 

by the APCO in the Flare Monitoring and Recording Plan. For a flare event that 

continues for more than one calendar day, each calendar day or venting of gases shall 

constitute a separate flare event. 

3.133.8Flare Gas: gas burned in a flare. 

3.14 Flare Minimization Plan (FMP): a document intended to meet the requirements of 

Section 6.5 of this Rule.

3.15 Flare Monitoring System: all flare monitoring and recording equipment used for the 

determination of flare operating parameters. Flare monitoring and recording 

equipment includes, but is not limited to, sample systems, transducers, transmitters, 

data acquisition equipment, data recording equipment, and video monitoring 

equipment and video recording equipment. 

3.16 Flexigas: a low BTU fuel gas produced by gasifying coke produced in a fluid-bed 

Coker. Due to the air used in the gasifying process, Flexigas is approximately 50%

nitrogen. 

3.17 3.9 Gaseous Fuel: any gases used as combustion fuel which include, but are not 

limited to, any natural, process, synthetic, landfill, sewage digester, or waste gases. 

Gaseous fuels include produced gas, pilot gas and, when burned, purge gas. 

3.18 MMBtu: million British thermal units. 

3.193.10 Non-Assisted Flare: a combustion device without any auxiliary provision for 

enhancing the mixing of air into its flame. This definition does not include those 

flares that by design provide excess air at the flare tip. 

3.203.11 NOx: any nitrogen oxide compounds 

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3.213.12 Open Flare: a vertically or horizontally oriented open pipe flare from which 

gases are released into the air before combustion is commenced. 

3.22 Operator: includes, but not limited to, any person who owns, leases, supervises, or 

operates a facility. 

3.23 Petroleum Refinery: a facility that processes petroleum, as defined in the Standard 

Industrial Classification Manual as Industry No. 2911, Petroleum Refining. For the 

purpose of this rule, all portions of the petroleum refining operation, including those 

at non-contiguous locations operating flares, shall be considered as one petroleum 

refinery. 

3.24 Pilot: an auxiliary burner used to ignite the vent gas routed to a flare. 

3.25 Pilot Gas: the gas used to maintain the presence of a flame for ignition of vent gases. 

3.263.13 Planned Flaring: a flaring operation that constitutes a designed and planned 

process at a source, and which would have been reasonably foreseen ahead of its 

actual occurrence, or is scheduled to occur. The operation of a flare for the purpose 

of performing equipment maintenance provided it does not exceed 200 hours per 

calendar year, or during compliance source testing or visible emission inspections is 

not considered planned flaring. Planned flaring includes, but is not limited to, the 

following flaring activities: 

 

3.26.13.13.1 Oil or gas well tests, well related work, tests ordered by a regulatory 

agency. 

 3.26.23.13.2 Equipment depressurization for maintenance purposes. 

 3.26.33.13.3 Equipment start-up or shutdown. 

 

3.26.43.13.4 Flaring of gas at production sources where no gas handling, gas 

injection or gas transmission facilities exists. 

3.26.53.13.5 Flaring of off-specification gas (i.e. non PUC quality gas), unless the 

operator can demonstrate that the gas must be flared for engineering or safety 

reasons, e.g., under emergency. 

3.26.6 The operation of a flare for the purpose of performing equipment 

maintenance. 

3.27 Prevention Measure: a component, system, procedure, or program that will minimize 

or eliminate flaring. 

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3.283.14 Public Utilities Commission (PUC) Quality Gas: any gaseous fuel, gas 

containing fuel where the sulfur content is no more than one-fourth (0.25) grain of 

hydrogen sulfide per one hundred (100) standard cubic feet and no more than five 

grains of total sulfur per one hundred (100) standard cubic feet. PUC quality gas shall 

also mean high methane (at least 80% by volume) gas as specified in PUC's General 

Order 58-A. 

3.293.15 Purge Gas: Nitrogen, carbon dioxide, liquefied petroleum gas, refinery fuel 

gas, or natural gas, any of which can be used to maintain a non-explosive mixture of 

gases in the flare header or provide sufficient exit velocity to prevent any regressive 

flame travel back into the flare header. 

3.30 Refinery Fuel Gas: a combustible gas, which is a by-product of the refinery process. 

3.31 Reportable Flaring Event: any flaring where more than 500,000 standard cubic feet 

of vent gas is flared per calendar day, or where sulfur oxide emissions are greater

than 500 pounds per calendar day. A reportable flaring event ends when it can be 

demonstrated by monitoring required in Section 6.8 that the integrity of the water seal 

has been maintained sufficiently to prevent vent gas to the flare tip. For flares 

without water seals or water seal monitors as required by Section 6.8, a reportable 

flaring event ends when the rate of flow of vent gas falls below 0.12 feet per second. 

3.32 Representative Sample: a sample of vent gas collected from the location as approved 

for flare monitoring and analyzed utilizing test methods specified in Section 6.3.4. 

3.33 Shutdown: the procedure by which the operation of a process unit or piece of 

equipment is stopped due to the end of a production run, or for the purpose of 

performing maintenance, repair and replacement of equipment. Stoppage caused by 

frequent breakdown due to poor maintenance or operator error shall not be deemed a 

shutdown. 

3.34 Startup: the procedure by which a process unit or piece of equipment achieves normal 

operational status, as indicated by such parameters as temperature, pressure, feed rate 

and product quality. 

3.353.16 Steam-Assisted Flare: a combustion device where steam is injected into the 

combustion zone to promote turbulence for the mixing of the combustion air before it 

is introduced to the flame. 

3.36 Thermal oxidizer: an enclosed or partially enclosed combustion device, other than a 

flare, that is used to oxidize combustible gases. 

3.373.17 Total Organic Gases (TOG): all hydrocarbon compounds containing 

hydrogen and carbon with or without other chemical elements. 

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3.38 Turnaround: a planned activity involving shutdown and startup of one or several 

process units for the purpose of performing periodic maintenance, repair, 

replacement of equipment or installation of new equipment. 

3.18 U.S. EPA: the United States Environmental Protection Agency.

3.39 Vent Gas: any gas directed into a flare, excluding assisting air or steam, flare pilot 

gas, and any continuous purge gases. 

3.403.19 Volatile Organic Compound (VOC): as defined in Rule 1020 (Definitions). 

3.41 Water Seal: a liquid barrier, or seal, to prevent the passage of gas. Water seals 

provide a positive means of flash-back prevention in addition to enabling the 

upstream flare system header to operate at a slight positive pressure at all times. 

4.0 Exemptions 

4.1 Flares operated in municipal solid waste landfills subject to the requirements of 

Rule 4642 (Solid Waste Disposal Sites) are exempt from this rule. 

4.2 Flares that are subject to the requirements of 40 CFR 60 Subpart WWW 

(Standards of Performance for Municipal Waste Landfills), or Subpart Cc 

(Emission Guidelines and Compliance Times for Municipal Solid Waste 

Landfills) are exempt from this rule. 

4.3 Except for the recordkeeping requirements in Section 6.1.46.2.4 the 

requirements of this rule shall not apply to any stationary source that has the 

potential to emit, for all processes, less than ten (10.0) tons per year of VOC 

and less than ten (10.0) tons per year of NOx. 

5.0 Requirements 

The owner or operator of any source subject to this rule shall comply with the following 

requirements: 

5.1 Flares that are permitted to operate only during an emergency are not subject to the 

requirements of Sections 5.6 and 5.7. 

5.2 The flame shall be present at all times when combustible gases are vented through the 

flare. 

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5.3 The outlet shall be equipped with an automatic ignition system, or, shall operate with 

a pilot flame present at all times when combustible gases are vented through the flare, 

except during purge periods for automatic-ignition equipped flares. 

5.4 Except for flares equipped with a flow-sensing ignition system, a heat sensing device 

such as a thermocouple, ultraviolet beam sensor, infrared sensor, or an alternative 

equivalent device, capable of continuously detecting at least one pilot flame or the 

flare flame is present shall be installed and operated. 

5.5 Flares that use flow-sensing automatic ignition systems and which do not use a 

continuous flame pilot shall use purge gas for purging. 

5.6 Open flares (air-assisted, steam-assisted, or non-assisted) in which the flare gas 

pressure is less than 5 psig shall be operated in such a manner that meets the 

provisions of 40 CFR 60.18. The requirements of this section shall not apply to 

Coanda effect flares. 

5.7 Ground-level enclosed flares shall meet the following emission standards: 

Type of Flare and Heat Release 

Rate in MMBtu/hr 

VOC (lb/MMBtu) NOx (lb/MMBtu) 

Without Steam-assist 

 <10 MMBtu 0.0051 0.0952 

 10-100 MMBtu 0.0027 0.1330 

 >100 MMBtu 0.0013 0.5240 

With Steam-assist 

All 0.14 as TOG 0.068 

5.8 Flare Minimization Plan

Effective on and after July 1, 2011, flaring is prohibited unless it is consistent with an 

approved flare minimization plan (FMP), pursuant to Section 6.5, and all 

commitments listed in that plan have been met. This standard shall not apply if the 

APCO determines that the flaring is caused by an emergency as defined by Section 

3.7 and is necessary to prevent an accident, hazard or release of vent gas directly to 

the atmosphere. 

 

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5.9 Petroleum Refinery SO2 Performance Targets

5.9.1 Effective on and after January 1, 2011, the operator of a petroleum refinery

shall minimize sulfur dioxide flare emissions to less than 1.50 tons per million 

barrels of crude processing capacity, calculated as an average over one 

calendar year. 

5.9.2 Effective on and after January 1, 2017, the operator of a petroleum refinery 

shall minimize sulfur dioxide flare emissions to less than 0.50 tons per million

barrels of crude processing capacity, calculated as an average over one 

calendar year. 

5.10 Effective on and after July 1, 2011, the operator of a flare subject to flare 

minimization requirements pursuant to Section 5.8 shall monitor the vent gas flow to 

the flare with a flow measuring device or other parameters as specified in the Permit

to Operate. The operator shall maintain records pursuant to Section 6.1.7. Flares that 

the operator can verify, based on permit conditions, are not capable of producing

reportable flare events pursuant to Section 6.2.2 shall not be required to monitor vent 

gas flow to the flare. 

5.11 Effective on and after July 1, 2011, the operator of a petroleum refinery or a flare 

with a flaring capacity equal to or greater than 50 MMBtu/hr shall monitor the flare 

pursuant to Sections 6.6, 6.7, 6.8, 6.9, and 6.10.

6.0 Administrative Requirements 

6.1 Compliance Determination 

6.1.1 Upon request the operator of flares that are subject to Section 5.6 shall make 

available to the APCO the compliance determination records that demonstrate 

compliance with the provisions of 40 CFR 60.18, (c)(3) through (c)(5). 

6.1.2 The operator of ground-level enclosed flares shall conduct source testing at 

least once every 12 months to demonstrate compliance with Section 5.7. The 

operator shall submit a copy of the testing protocol to the APCO at least 30 

days in advance of the scheduled testing. The operator shall submit the 

source test results not later than 45 days after completion of the source 

testing. 

6.16.2 Recordkeeping 

The following records shall be maintained, retained on-site for a minimum of 

five years, and made available to the APCO, ARB, and U.S. EPA upon request: 

 

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6.1.16.2.1 Copy of the compliance determination conducted pursuant to Section 

6.1.1 6.4.1. 

6.1.26.2.2 Copy of the source testing result conducted pursuant to Section 6.1.2

6.4.2. 

6.1.36.2.3 For flares used during an emergency, record of the duration of flare 

operation, amount of gas burned, and the nature of the emergency situation. 

6.1.46.2.4 Beginning January 1, 2007, facilities Operators claiming an 

exemption pursuant to Section 4.3 shall record annual throughput, material 

usage, or other information necessary to demonstrate an exemption under that 

section. 

6.1.5 Effective on and after July 1, 2011, a copy of the approved flare 

minimization plan pursuant to Section 6.5.

6.1.6 Effective on and after July 1, 2012, where applicable, a copy of annual 

reports submitted to the APCO pursuant to Section 6.2.

6.1.7 Effective on and after July 1, 2011, where applicable, monitoring data

collected pursuant to Sections 5.10, 6.6, 6.7, 6.8, 6.9, and 6.10.

6.2 Flare Reporting

 6.2.1 Unplanned Flaring Event 

 Effective on and after July 1, 2011, the operator of a flare subject to flare 

minimization plans pursuant to Section 5.8 of this rule shall notify the APCO 

of an unplanned flaring event within 24 hours after the start of the next 

business day or within 24 hours of their discovery, which ever occurs first. 

The notification shall include the flare source identification, the start date and 

time, and the end date and time. 

6.2.2 Reportable Flaring Event

Effective on and after July 1, 2012, and annually thereafter, the operator of a 

flare subject to flare minimization plans pursuant to Section 5.8 shall submit 

an annual report to the APCO that summarizes all Reportable Flaring Events 

as defined in Section 3.0 that occurred during the previous 12 month period. 

The report shall be submitted within 30 days following the end of the twelve 

month period of the previous year. The report shall include, but is not 

limited to all of the following: 

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6.2.2.1 The results of an investigation to determine the primary cause and 

contributing factors of the flaring event; 

6.2.2.2 Any prevention measures considered or implemented to prevent 

recurrence together with a justification for rejecting any measures 

that were considered but not implemented; 

6.2.2.3 If appropriate, an explanation of why the flaring was an emergency 

and necessary to prevent accident, hazard or release of vent gas to 

the atmosphere, or where, due to a regulatory mandate to vent a 

flare, it cannot be recovered, treated and used as a fuel gas at the 

facility; and 

6.2.2.4 The date, time, and duration of the flaring event.

6.2.3 Annual Monitoring Report 

Effective on and after July 1, 2012, and annually thereafter, the operator of a 

flare subject to flare monitoring requirements pursuant to Sections 5.10, 6.6, 

6.7, 6.8, 6.9, and 6.10, as appropriate, shall submit an annual report to the 

APCO within 30 days following the end of each 12 month period. The report 

shall include the following: 

6.2.3.1 The total volumetric flow of vent gas in standard cubic feet for each 

day. 

6.2.3.2 Hydrogen sulfide content, methane content, and hydrocarbon content 

of vent gas composition pursuant to Section 6.6.

6.2.3.3 If vent gas composition is monitored by a continuous analyzer or 

analyzers pursuant to Section 5.11, average total hydrocarbon content 

by volume, average methane content by volume, and depending upon 

the analytical method used pursuant to Section 6.3.4, total reduced 

sulfur content by volume or hydrogen sulfide content by volume of 

vent gas flared for each hour of the month. 

6.2.3.4 If the flow monitor used pursuant to Section 5.10 measures molecular 

weight, the average molecular weight for each hour of each month. 

6.2.3.5 For any pilot and purge gas used, the type of gas used, the volumetric 

flow for each day and for each month, and the means used to 

determine flow. 

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6.2.3.6 Flare monitoring system downtime periods, including dates and 

times. 

6.2.3.7 For each day and for each month provide calculated sulfur dioxide 

emissions. 

6.2.3.8 A flow verification report for each flare subject to this rule. The flow 

verification report shall include flow verification testing pursuant to 

Section 6.3.5. 

6.3 Test Methods 

The test methods listed below shall be used to demonstrate compliance with this rule. 

Alternate equivalent test methods may be used provided the test methods have been 

approved by the APCO and EPA. 

6.3.1 VOC, measured and calculated as carbon, shall be determined by EPA 

Method 25, except when the outlet concentration must be below 50 ppm in 

order to meet the standard, in which case Method 25a may be used, and 

analysis of halogenated exempt compounds shall be analyzed by EPA Method 

18 or ARB Method 422 “Determination of Volatile organic Compounds in 

Emission from Stationary Sources”. The VOC concentration in ppmv shall 

be converted to pounds per million Btu (lb/MMBtu) by using the following 

equation: 

 VOC in lb/MMBtu = 

)%9

)/

O2

MMBtu

.20()10135.1( −

,()(

6 xx

dscfFxdryppmv

 

 Where: F = As determined by EPA Method 19 

6.3.2 NOx emissions in pounds per million BTU shall be determined by using EPA 

Method 19. 

 

 6.3.3 NOx and O2 concentrations shall be determined by using EPA Method 3A, 

EPA Method 7E, or ARB 100. 

 

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6.3.4 Testing and Sampling Methods for Flare Monitoring

 Effective on and after July 1, 2011 operators subject to vent gas composition 

monitoring requirements pursuant to Section 6.6 shall use the following test 

methods as appropriate, or by an alternative method approved by the APCO, 

ARB and EPA: 

6.3.4.1 Total hydrocarbon content and methane content of vent gas shall be 

determined using ASTM Method D 1945-96, ASTM Method UOP 

539-97, EPA Method 18, or EPA Method 25A or 25B, 

6.3.4.2 Hydrogen sulfide content of vent gas shall be determined using 

ASTM Method D 1945-96, ASTM Method UOP 539-97, ASTM

Method D 4084-94, or ASTM Method D 4810-88. 

6.3.4.3 If vent gas composition is monitored with a continuous analyzer 

employing gas chromatography the minimum sampling frequency 

shall be one sample every 30 minutes. 

6.3.4.3 If vent gas composition is monitored using continuous analyzers not 

employing gas chromatography, the total reduced sulfur content of 

vent gas shall be determined by using EPA Method D4468-85. 

 6.3.5 Flow Verification Test Methods

For purposes of the flow verification report required by Section 6.2.3.9, vent 

gas flow shall be determined using one or more of the following methods, or 

by any alternative method approved by the APCO, ARB, and EPA : 

6.3.5.1 EPA Methods 1 and 2; 

6.3.5.2 A verification method recommended by the manufacturer of the flow 

monitoring equipment installed pursuant to Section 5.10.

6.3.5.3 Tracer gas dilution or velocity. 

6.3.5.4 Other flow monitors or process monitors that can provide 

comparison data on a vent stream that is being directed past the 

ultrasonic flow meter.

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6.46.1 Compliance Determination 

6.4.16.1.1 Upon request the operator of flares that are subject to Section 5.6 

shall make available to the APCO the compliance determination records that 

demonstrate compliance with the provisions of 40 CFR 60.18, (c)(3) through 

(c)(5). 

6.4.26.1.2 The operator of ground-level enclosed flares shall conduct source 

testing at least once every 12 months to demonstrate compliance with Section 

5.7. The operator shall submit a copy of the testing protocol to the APCO at 

least 30 days in advance of the scheduled testing. The operator shall submit 

the source test results not later than 45 days after completion of the source 

testing. 

6.5 Flare Minimization Plan

 6.5.1 By July 1, 2010, the operator of a petroleum refinery flare or any flare that 

has a flaring capacity of greater than or equal to 5.0 MMBtu per hour shall 

submit a flare minimization plan (FMP) to the APCO for approval. The 

FMP shall include, but not be limited to: 

6.5.1.1 A description and technical specifications for each flare and 

associated knock-out pots, surge drums, water seals and flare gas 

recovery systems. 

6.5.1.2 Detailed process flow diagrams of all upstream equipment and 

process units venting to each flare, identifying the type and location 

of all control equipment. 

6.5.1.3 A description of equipment, processes or procedures the operator 

plans to install or implement to eliminate or minimize flaring and 

planned date of installation or implementation. 

6.5.1.4 An evaluation of prevention measures to reduce flaring that has 

occurred or may be expected to occur during planned major 

maintenance activities, including startup and shutdown. 

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6.5.1.5 An evaluation of preventative measures to reduce flaring that may be 

expected to occur due to issues of gas quantity and quality. The 

evaluation shall include an audit of the vent gas recovery capacity of 

each flare system, the storage capacity available for excess vent 

gases, and the scrubbing capacity available for vent gases including 

any limitations associated with scrubbing vent gases for use as a fuel; 

and shall determine the feasibility of reducing flaring though the 

recovery, treatment and use of the gas or other means.

6.5.1.6 An evaluation of preventative measures to reduce flaring caused by 

the recurrent failure of air pollution control equipment, process 

equipment, or a process to operate in a normal or usual manner. 

The evaluation shall determine the adequacy of existing maintenance 

schedules and protocols for such equipment. For purposes of this 

Section, a failure is recurrent if it occurs more than twice during any 

five year period as a result of the same cause as identified in 

accordance with Section 6.2.2. 

6.5.1.7 Any other information requested by the APCO as necessary for 

determination of compliance with applicable provisions of this rule. 

 6.5.2 Every five years after the initial FMP submittal, the operator shall submit an 

updated FMP for each flare to the APCO for approval. The current FMP 

shall remain in effect until the updated FMP is approved by the APCO. If

the operator fails to submit an updated FMP as required by this section, the 

existing FMP shall no longer be considered an approved plan. 

 

 6.5.3 An updated FMP shall be submitted by the operator pursuant to Section 6.5

addressing new or modified equipment, prior to installing the equipment. 

Updated FMP submittals are only required if: 

 6.5.3.1 The equipment change would require an authority to construct 

(ATC) and would impact the emissions from the flare, and 

 6.5.3.2 The ATC is deemed complete after June 18, 2009, and 

 6.5.3.3 The modification is not solely the removal or decommissioning of 

equipment that is listed in the FMP, and has no associated increase in 

flare emissions. 

 

 

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6.5.4 When submitting the initial FMP, or updated FMP, the operator shall 

designate as confidential any information claimed to be exempt from public 

disclosure under the California Public Records Act, Government Code 

Section 6250 et seq. If a document is submitted that contains information 

designated confidential, the operator shall provide a justification for this 

designation and shall submit a separate copy of the document with the 

information designated confidential redacted. 

6.6 Vent Gas Composition Monitoring

Effective on and after July 1, 2011, the operator of a petroleum refinery flare or any

flare that has a flaring capacity equal to or greater than 50 MMBtu per hour shall 

monitor vent gas composition using one of the five methods pursuant to Section 6.6.1 

through Section 6.6.5 as appropriate. 

6.6.1 Sampling that meets the following requirements: 

6.6.1.1 If the flow rate of vent gas flared in any consecutive 15-minute 

period continuously exceeds 330 standard cubic feet per minute 

(SCFM), a sample shall be taken within 15 minutes. The sampling 

frequency thereafter shall be one sample every three hours and shall 

continue until the flow rate of vent gas flared in any consecutive 15-

minute period is continuously 330 SCFM or less. In no case shall a 

sample be required more frequently than once every 3 hours. 

6.6.1.2 Samples shall be analyzed pursuant to Section 6.3.4. 

6.6.2 Integrated sampling that meets the following requirements: 

6.6.2.1 If the flow rate of vent gas flared in any consecutive 15 minute 

period continuously exceeds 330 SCFM, integrated sampling shall 

begin within 15 minutes and shall continue until the flow rate of 

vent gas flared in any consecutive 15 minute period is continuously 

330 SCFM or less. 

6.6.2.2 Integrated sampling shall consist of a minimum of one aliquot for 

each 15-minute period until the sample container is full. If 

sampling is still required pursuant to Section 6.6.2.1, a new sample 

container shall be placed in service within one hour after the 

previous sample was filled. A sample container shall not be used 

for a sampling period that exceeds 24 hours. 

6.6.2.3 Samples shall be analyzed pursuant to Section 6.3.4. 

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6.6.3 Continuous analyzers that meet the following requirements: 

6.6.3.1 The analyzers shall continuously monitor for total hydrocarbon 

methane, and depending upon the analytical method used pursuant 

to Section 6.3.4, hydrogen sulfide or total reduced sulfur. 

6.6.3.2 The hydrocarbon analyzer shall have a full-scale range of 100% 

total hydrocarbon. 

6.6.3.3 Each analyzer shall be maintained to be accurate to within 20% 

when compared to any field accuracy tests or to within 5% of full 

scale. 

6.6.4 Continuous analyzers employing gas chromatography that meet the following 

requirements: 

6.6.4.1 The gas chromatography system shall monitor for total 

hydrocarbon, methane, and hydrogen sulfide. 

6.6.4.2 The gas chromatography system shall be maintained to be accurate 

within 5% of full scale.

6.6.5 Monitor sulfur content using a colorimetric tube system on a daily basis, and 

monitor vent gas hydrocarbon on a weekly basis by collecting samples and 

having them tested pursuant to a method in Section 6.3.4.

 6.6.6 If flares share a common header, a sample from the header will be deemed 

representative of vent gas composition for all flares served by the header. 

6.6.7 The operator shall provide the APCO with access to the monitoring system to 

collect vent gas samples to verify the analysis required by Section 5.11.

6.7 Pilot and Purge Gas Monitoring

 Effective on and after July 1, 2011, the operator of a petroleum refinery flare or any

flare that has a flaring capacity equal to or greater than 50 MMBtu per hour shall 

monitor the volumetric flows of purge and pilot gases with flow measuring devices or 

other parameters as specified on the Permit to Operate so that volumetric flows of 

pilot and purge gas may be calculated based on pilot design and the parameters 

monitored. 

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6.8 Water Seal Monitoring

 Effective on and after July 1, 2011, the operator of a petroleum refinery flare or any

flare that has a flaring capacity equal to or greater than 50 MMBtu per hour with a 

water seal shall monitor and record the water level and pressure of the water seal that 

services each flare daily or as specified on the Permit to Operate. 

6.9 General Monitoring 

Effective on and after July 1, 2011, the operator of a petroleum refinery flare or any 

flare that has a flaring capacity equal to or greater than 50 MMBtu per hour shall 

comply with the following, as applicable: 

6.9.1 Periods of flare monitoring system inoperation greater than 24 continuous 

hours shall be reported by the following working day, followed by 

notification of resumption of monitoring. Periods of inoperation of 

monitoring equipment shall not exceed 14 days per any 18 consecutive month 

period. Periods of flare monitoring system inoperation do not include the 

periods when the system feeding the flare is not operating. 

6.9.2 During periods of inoperation of continuous analyzers or auto-samplers 

installed pursuant to Section 6.6, operators responsible for monitoring shall 

take one sample within 30 minutes of the commencement of flaring, from the 

flare header or from an alternate location at which samples are representative 

of vent gas composition and have samples analyzed pursuant to Section 6.3.4. 

During periods of inoperation of flow monitors required by Section 5.10, 

flow shall be calculated using good engineering practices. 

6.9.3 Maintain and calibrate all required monitors and recording devices in 

accordance with the applicable manufacturer’s specifications. In order to 

claim that a manufacturer’s specification is not applicable, the person 

responsible for emissions must have, and follow, a written maintenance 

policy that was developed for the device in question. The written policy must 

explain and justify the difference between the written procedure and the 

manufacturer’s procedure. 

6.9.4 All in-line continuous analyzer and flow monitoring data must be 

continuously recorded by an electronic data acquisition system capable of 

one-minute averages. Flow monitoring data shall be recorded as one-minute 

averages. 

4311 – 16 Revised Proposed 

Amendments to Rule 4311
Revised Proposed June 18, 2009

6.10 Video Monitoring

Effective on and after July 1, 2011, the operator of a petroleum refinery flare shall 

install and maintain equipment that records a real-time digital image of the flare and 

flame at a frame rate of no less than one frame per minute. The recorded image of 

the flare shall be of sufficient size, contrast, and resolution to be readily apparent in 

the overall image or frame. The image shall include an embedded date and time 

stamp. The equipment shall archive the images for each 24-hour period. In lieu of 

video monitoring the operator may use an alternative monitoring method that 

provides data to verify date, time, vent gas flow, and duration of flaring events. 

7.0 Compliance Schedule 

Operators of flares that are exempt under Section 4.0 that lose exemption status shall not 

operate flares until in full compliance with all applicable requirements of this rule effective on 

the date the exemption status is lost.

7.1 Flares at facilities with a potential to emit more than 25 tons per year of VOC or 

NOx that are installed and in operation before June 20, 2002 shall be in compliance 

with this rule by December 20, 2003. 

7.2 Flares, at facilities with a potential to emit more than 25 tons per year of VOCs or 

NOx, that are installed or constructed on or after June 20, 2002, shall be in 

compliance with this rule upon initial operation and thereafter.

7.3 Flares that are installed before June 15, 2006 at facilities, which have the potential to 

emit between 10 tons per year and 25 tons per year of VOC or NOX shall 

demonstrate compliance with this rule by January 1, 2008.

7.4 Flares, at facilities with a potential to emit between 10 tons per year and 25 tons per 

year of VOC or NOx that are installed or constructed on or after June 15, 2006, shall 

be in compliance with this rule upon initial operation and thereafter.

4311 – 17 Revised Proposed 

Amendments to Rule 4311
Revised Proposed June 18, 2009

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4311 – 18 Revised Proposed 

Amendments to Rule 4311