(Adopted February 13, 1998)(Amended November 4, 2005) 

RULE 1118. CONTROL OF EMISSIONS FROM REFINERY FLARES

(a) Purpose and Applicability 

The purpose of Rule 1118 is to monitor and record data on refinery and related 

flaring operations, and to control and minimize flaring and flare related emissions. 

The provisions of this rule are not intended to preempt any petroleum refinery, 

sulfur recovery plant and hydrogen production plant operations and practices with 

regard to safety. This rule applies to all flares used at petroleum refineries, sulfur 

recovery plants and hydrogen production plants. 

(b) Definitions 

For the purpose of this rule, the following definitions shall apply: 

(1) CLEAN SERVICE FLARE is a flare that is designed and configured by 

installation to combust only natural gas, hydrogen gas and/or liquefied 

petroleum gas, or any other gas(es) with a fixed composition vented from 

specific equipment which has been determined to be equivalent and 

approved in writing by the Executive Officer. 

(2) EMERGENCY is a condition beyond the reasonable control of the owner 

or operator of a flare requiring immediate corrective action to restore 

normal and safe operation, which is caused by a sudden, infrequent and 

not reasonably preventable equipment failure, natural disaster, act of war 

or terrorism or external power curtailment, excluding power curtailment 

due to an interruptible power service agreement from a utility. For the 

purpose of this rule, a repetitive event from the same equipment caused by 

poor maintenance, or a condition caused by operator error that results in a 

flare event shall not be deemed an emergency. 

(3) EMERGENCY SERVICE FLARE is a flare other than clean service flare 

that is designed and configured by installation to combust only vent gases 

as a result of any situation arising from sudden and unforeseeable events 

beyond the reasonable control of the owner or operator of the gas flare 

which require immediate corrective action to restore normal and safe 

operation including emergency process upset condition, equipment 

malfunction or breakdown, electrical power failure, steam failure, cooling 

1118 - 1 
Rule 1118 (Cont.) (Amended November 4, 2005) 

air or water failure, instrument air failure, reflux failure, heat exchanger 

tube failure, loss of heat, excess heat, fire and explosion. 

(4) ESSENTIAL OPERATIONAL NEED is an activity determined by the 

Executive Officer to meet one of the following: 

(A) Temporary fuel gas system imbalance due to: 

(i) Inability to accept gas compliant with Rule 431.1 by an 

electric generation unit at the facility that produces 

electricity to be used in a state grid system, or 

(ii) Inability to accept gas compliant with Rule 431.1 by a third 

party that has a contractual gas purchase agreement with 

the facility, or 

(iii) The sudden shutdown of a refinery fuel gas combustion 

device for reasons other than poor maintenance or operator 

error; 

(B) Relief valve leakage due to malfunction; 

(C) Venting of streams that cannot be recovered due to incompatibility 

with recovery system equipment or with refinery fuel gas systems, 

including supplemental natural gas or other gas compliant with 

Rule 431.1 that is used for the purpose of maintaining the higher 

heating value of the vent gas above 300 British Thermal Units per 

standard cubic foot. Such streams include inert gases, oxygen, 

gases with low or high molecular weights outside the design 

operating range of the recovery system equipment and gases with 

low or high higher heating values that could render refinery fuel 

gas systems and/or combustion devices unsafe; 

(D) Venting of clean service streams to a clean service flare or a 

general service flare; 

(E) Intermittent minor venting from: 

(i) Sight glasses; 

(ii) Compressor bottles; 

(iii) Sampling systems; or 

(iv) Pump or compressor vents; or 

(F) An emergency situation in the process operation resulting from the 

vessel operating pressure rising above pressure relief devices’ set 

points, or maximum vessel operating temperature set point. 

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Rule 1118 (Cont.) (Amended November 4, 2005) 

(5) FLARE is a combustion device that uses an open flame to burn 

combustible gases with combustion air provided by uncontrolled ambient 

air around the flame. This consists of both ground and elevated flares. 

When used as a verb means the combustion of vent gases in a flare device. 

(6) FLARE EVENT is 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 owner or 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 

Executive Officer in the Flare Monitoring and Recording Plan. For a flare 

event that continues for more than 24 hours, each day of venting of gases 

shall constitute a flare event. 

(7) FLARE GAS RECOVERY SYSTEM is a system comprised of 

compressors, pumps, heat exchangers, knock-out pots and water seals, 

installed to prevent or minimize the combustion of vent gas in a flare. 

(8) FLARE MINIMIZATION PLAN is a document intended to meet the 

requirements of subdivision (e). 

(9) FLARE MONITORING SYSTEM is the monitoring and recording 

equipment used for the determination of flare operating parameters, 

including higher heating value, total sulfur concentration, standard 

volumetric flow rate, and/or on/off flow indication. 

(10) GENERAL SERVICE FLARE is a flare that is not defined in paragraphs 

(b)(1) or (b)(3) that is designed and configured by installation to combust 

vent gases as a result of any situation including, but not limited to, relief 

of excess operating pressures, tank vapor displacement, start-ups, 

shutdowns, process unit turnarounds and blowdowns, and scheduled and 

unscheduled maintenance and clean up. 

(11) HYDROGEN PRODUCTION PLANT is a facility that produces 

hydrogen by steam hydrocarbon reforming, partial oxidation of 

hydrocarbons, or other processes, using refinery fuel gas, process gas or 

natural gas, and which supplies hydrogen for petroleum refinery 

operations. 

(12) NATURAL GAS is a mixture of gaseous hydrocarbons, with at least 80 

percent methane (by volume), and of pipeline quality, such as the gas sold 

or distributed by any utility company regulated by the California Public 

Utilities Commission. 

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Rule 1118 (Cont.) (Amended November 4, 2005) 

(13) NOTICE OF SULFUR DIOXIDE EXCEEDANCE is a notice issued by 

the Executive Officer to the owner or operator when the petroleum 

refinery has exceeded a performance target of this rule. 

(14) PETROLEUM REFINERY is 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. 

(15) PILOT is an auxiliary burner used to ignite the vent gas routed to a flare. 

(16) PURGE GAS is a continuous gas stream introduced into a flare header, 

flare stack and /or flare tip for the purpose of maintaining a positive flow 

that prevents the formation of an explosive mixture due to ambient air 

ingress. 

(17) REPRESENTATIVE SAMPLE is a sample of vent gas collected from the 

location as approved in the Flare Monitoring and Recording Plan and 

analyzed utilizing test methods specified in subdivision (j). 

(18) SAMPLING FLARE EVENT is any flare event for a specific flare 

exceeding either a flow rate of 330 standard cubic feet per minute 

continuously for a period greater than 15 minutes, or any other flare event, 

as requested by the petroleum refinery and approved in writing by the 

Executive Officer. Sampling flare events that occur within 15 minutes of 

each other are considered a single event if the facility can demonstrate to 

the satisfaction of the Executive Officer that the events had a common 

cause and the release of vent gas originated from the same process unit. 

(19) SHUTDOWN is 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. 

(20) SPECIFIC CAUSE ANALYSIS is a process used by a facility subject to 

this rule to investigate the cause of a flare event, identify corrective 

measures and prevent recurrence of a similar event. 

(21) STARTUP is 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. 

1118 - 4 
Rule 1118 (Cont.) (Amended November 4, 2005) 

(22) SULFUR RECOVERY PLANT is a facility that recovers elemental sulfur 

or sulfur compounds from sour gases and/or sour water generated by 

petroleum refineries. 

(23) TURNAROUND is 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. 

(24) VENT GAS is any gas generated at a facility subject to this rule that is 

routed to a flare, excluding assisting air or steam, which are injected in the 

flare combustion zone or flare stack via separate lines. 

(25) VOLATILE ORGANIC COMPOUNDS (VOC) is as defined in Rule 102. 

(c) Requirements 

The owner or operator of a petroleum refinery, sulfur recovery plant or hydrogen 

production plant subject to this rule shall: 

(1) Effective January 1, 2006: 

(A) Maintain a pilot flame present at all times a flare is operational. 

(B) Operate all flares in a smokeless manner with no visible emissions 

except for periods not to exceed a total of five minutes during two 

consecutive hours, as determined by the test method in paragraph 

(j)(3). 

(C) Conduct an annual acoustical or temperature leak survey of all 

pressure relief devices connected directly to a flare and repair 

leaking pressure relief devices no later than the next turnaround. 

The survey shall be conducted no earlier than 90 days prior to the 

scheduled process unit turnaround. 

(D) Conduct a Specific Cause Analysis for any flare event, excluding 

planned shutdown, planned startup and turnarounds, with 

emissions exceeding either: 

(i) 100 pounds of VOC; 

(ii) 500 pounds of sulfur dioxide; 

(iii) 500,000 standard cubic feet of vent gas combusted, 

(E) Conduct an analysis and determine the relative cause of any other 

flare events where more than 5,000 standard cubic feet of vent gas 

are combusted. When it is not feasible to determine relative cause, 

state the reason why it was not feasible to make the determination. 

1118 - 5 
Rule 1118 (Cont.) (Amended November 4, 2005) 

(2) Effective September 1, 2006, submit the following information to the 

Executive Officer: 

(A) Detailed process flow diagrams of all upstream equipment and 

process units venting to each flare and a complete description and 

technical specifications for each flare system components such as 

flares, associated knock-out pots, surge drums, water seals and 

flare gas recovery systems, and an audit of the vent gas recovery 

capacity of each flare system, the available storage 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 

(B) A description of the equipment, processes and procedures installed 

or implemented within the last five years to reduce flaring; and 

(C) A descriptions of any equipment, processes or procedures the 

owner or operator plans to install or implement to eliminate or 

reduce flaring. The description shall specify the scheduled year of 

installation or implementation. 

(3) Effective January 1, 2007, submit to the Executive Officer an evaluation 

of options to reduce flaring during planned shutdowns, startups and 

turnarounds, including, but not limited to slower vessel depressurization, 

storing vent gases. 

(4) Effective January 1, 2007, operate all flares in such a manner that 

minimizes all flaring and that no vent gas is combusted except during 

emergencies, shutdowns, startups, turnarounds or essential operational 

needs. Notwithstanding the effective date above, for the owner or 

operator of a facility subject to this rule that must install flare gas recovery 

and treatment system(s) to comply with the requirements of this 

paragraph, the effective date for a flare directly associated with the 

proposed flare gas recovery and treatment system shall be January 1, 

2009, provided the owner or operator submits a complete application to 

construct and operate a flare gas recovery and treatment system(s) by July 

1, 2006. For a facility installing flare gas treatment and recovery 

system(s) for more than two flares, the owner or operator may request an 

extension of the compliance date specified in this paragraph for the flare 

gas recovery and treatment system serving the additional flares to no later 

than January 1, 2010. The Executive Officer may grant an extension 

1118 - 6 
Rule 1118 (Cont.) (Amended November 4, 2005) 

provided that the owner or operator submits a request in writing to the 

Executive Officer prior to January 1, 2007, and the facility demonstrates 

that an extension is necessary due to operational needs. 

(5) Effective January 1, 2009, prevent the combustion in any flare of vent gas 

with a hydrogen sulfide concentration in excess of 160 ppm, averaged 

over three hours, excluding any vent gas resulting from an emergency, 

shutdown, startup, process upset or relief valve leakage. Notwithstanding 

the effective date above, for the owner or operator of a facility installing 

flare gas treatment and recovery system(s) for more than two flares to 

comply with the requirements of paragraph (c)(4), the owner or operator 

may request an extension of the compliance date specified in this 

paragraph for the flare gas recovery and treatment system serving the 

additional flares to no later than January 1, 2010. The Executive Officer 

may grant an extension provided that the owner or operator submits a 

request in writing to the Executive Officer prior to January 1, 2007, and 

the facility demonstrates that an extension is necessary due to operational 

needs. 

(d) Performance Targets 

(1) The owner or operator of a petroleum refinery subject to this rule shall 

minimize flare emissions and meet the following performance targets: 

(A) Beginning with calendar year 2006, minimize sulfur dioxide 

emissions from flares to less than 1.5 tons per million barrels of 

crude processing capacity, calculated as an average over one 

calendar year; 

(B) Beginning with calendar year 2008, minimize sulfur dioxide 

emissions from flares to less than 1 ton per million barrels of crude 

processing capacity, calculated as an average over one calendar 

year; 

(C) Beginning with calendar year 2010, minimize sulfur dioxide 

emissions from flares to less than 0.7 tons per million barrels of 

crude processing capacity, calculated as an average over one 

calendar year; 

(D) Beginning with calendar year 2012, minimize sulfur dioxide 

emissions from flares to less than 0.5 tons per million barrels of 

1118 - 7 
Rule 1118 (Cont.) (Amended November 4, 2005) 

crude processing capacity, calculated as an average over one 

calendar year. 

Compliance with the performance targets above shall be determined at the 

end of each calendar year based on the facility’s annual flare sulfur 

dioxide emissions normalized over the crude oil processing capacity in 

calendar year 2004. 

(2) In the event the petroleum refinery specific performance targets of 

paragraph (d)(1) are exceeded for any calendar year, the Executive Officer 

may issue a Notice of Sulfur Dioxide Exceedance that shall become a part 

of the refinery compliance record. 

(3) In the event the petroleum refinery specific performance targets of 

paragraph (d)(1) are exceeded for any calendar year, the owner or operator 

of the petroleum refinery shall: 

(A) Submit a Flare Minimization Plan pursuant to subdivision (e), and 

(B) Pay the District mitigation fees, within 90 days following the end 

of a calendar year for which the performance target was exceeded, 

according to the following schedule: 

(i) If excess emissions are no more than ten percent of the 

petroleum refinery specific performance target, $25,000 per 

ton for all sulfur dioxide emission(s) in excess of the 

applicable performance target, or 

(ii) If excess emissions are greater than ten percent but no more 

than twenty percent of the petroleum refinery specific 

performance target, $50,000 per ton of all sulfur dioxide 

emission(s) in excess of the applicable performance target, 

or 

(iii) If excess emissions are greater than twenty percent of the 

petroleum refinery specific performance target, $100,000 

per ton of all sulfur dioxide emission(s) in excess of the 

applicable performance target, and 

(iv) Notwithstanding the mitigation fee schedule of this 

subparagraph, the mitigation fee for a petroleum refinery 

for a calendar year will not exceed $4,000,000. 

(e) Flare Minimization Plan 

1118 - 8 
Rule 1118 (Cont.) (Amended November 4, 2005) 

(1) The owner or operator of a petroleum refinery exceeding the performance 

targets in paragraph (d)(1) shall submit, no later than 90 days from the end 

of a calendar year with emissions exceeding the annual performance 

target, a complete Flare Minimization Plan for approval by the Executive 

Officer. This plan shall constitute a plan pursuant to Rule 221 and fees 

shall be assessed pursuant to Rule 306. The plan application shall list all 

actions to be taken by the petroleum refinery to meet the performance 

targets in subdivision (d), including the following: 

(A) A complete description and technical specifications for each flare 

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

gas recovery systems; 

(B) Detailed process flow diagrams of all upstream equipment and 

process units venting to each flare, identifying the type and 

location of all control equipment; 

(C) Refinery policies and procedures to be implemented and any 

equipment improvements to minimize flaring and flare emissions 

and comply with the performance targets of paragraph (d)(1) for: 

(i) Planned turnarounds and other scheduled maintenance, 

based on an evaluation of these activities during the 

previous five years; 

(ii) Essential operational needs and the technical reason for 

which the vent gas cannot be prevented from being flared 

during each specific situation, based on supporting 

documentation on flare gas recovery systems, excess gas 

storage and gas treating capacity available for each flare; 

and 

(iii) Emergencies, including procedures that will be used to 

prevent recurring equipment breakdowns and process 

upset, based on an evaluation of the adequacy of 

maintenance schedules for equipment, process and control 

instrumentation. 

(D) Any flare gas recovery equipment and treatment system(s) to be 

installed to comply with the performance targets of paragraph 

(d)(1). 

(2) The Executive Officer will make the Flare Minimization Plans available 

for public review for a period of 60 days and respond to comments 

1118 - 9 
Rule 1118 (Cont.) (Amended November 4, 2005) 

received prior to plan approval. The Executive Officer will approve a 

plan upon determining that it meets the requirements of subdivision (e), or 

notify the owner or operator in writing that the plan is deficient and 

specify the required corrective action. If the owner or operator fails to 

submit an amendment within 45 days to correct the deficiency, the 

Executive Officer will deny the Flare Minimization Plan. The facility will 

be deemed in violation of this rule upon the Executive Officer’s denial of 

the Flare Minimization Plan. 

(3) The owner or operator of a petroleum refinery having an existing 

approved Flare Minimization Plan shall, no later than 90 days from the 

end of a calendar year, submit for the approval of the Executive Officer a 

revised Flare Minimization Plan, subject to the provisions of paragraphs 

(e)(1) and (e)(2), in the event the annual performance target for that 

calendar year is exceeded. 

(4) The owner and operator of a petroleum refinery shall comply with all 

provisions of an approved Flare Minimization Plan. Violation of any of 

the terms of the plan is a violation of this rule. 

(f) Flare Monitoring and Recording Plan Requirements 

(1) The owner or operator of an existing petroleum refinery, sulfur recovery 

plant or hydrogen production plant, as of November 4, 2005, shall: 

(A) On or before June 30, 2006, submit a Revised Flare Monitoring 

and Recording Plan, complete with an application and appropriate 

fees, for each facility to the Executive Officer for approval. This 

plan shall constitute a plan pursuant to Rule 221 and fees shall be 

assessed pursuant to Rule 306. Each Flare Monitoring and 

Recording Plan shall contain the information described in 

paragraph (f)(3) of this rule. 

(B) Comply with the most current Flare Monitoring and Recording 

Plan approved by the Executive Officer and in effect prior to 

November 4, 2005. The Executive Officer will amend the plan to 

include Rule 1118 as adopted on February 13, 1998, to become 

part of the plan and will issue the amended plan within 30 days of 

November 4, 2005. The amended plan shall remain in effect until 

the Revised Flare Monitoring and Recording Plan, submitted 

1118 - 10 
Rule 1118 (Cont.) (Amended November 4, 2005) 

pursuant to subparagraph (f)(1)(A) is approved by the Executive 

Officer. 

(C) The owner or operator of a petroleum refinery, sulfur plant or 

hydrogen plant shall comply with all provisions of an approved 

Flare Monitoring and Recording Plan. Violation of any of the 

terms of the plan is a violation of this rule. 

(2) The owner or operator of a new or an existing non-operating petroleum 

refinery, sulfur recovery plant or hydrogen production plant starting or 

restarting operations on or after February 13, 1998 shall: 

(A) Provide the Executive Officer a written notice of the date of startup no later than seven (7) days prior to starting or commencing 

operations. 

(B) No later than 180 days prior to the initial startup or resumption of 

operations, submit a complete application and appropriate fees for 

a Flare Monitoring and Recording Plan to the Executive Officer 

for approval. This plan shall constitute a plan pursuant to Rule 221 

and fees shall be assessed pursuant to Rule 306. Each Flare 

Monitoring and Recording Plan shall contain the information 

described in paragraph (f)(3) of this rule. 

(3) Each Flare Monitoring and Recording Plan or Revised Flare Monitoring 

and Recording Plan shall include, at a minimum, the following: 

(A) A facility plot plan showing the location of each flare in relation to 

the general plant layout. 

(B) Type of flare service, as defined in subdivision (b), and 

information regarding design capacity, operation and maintenance 

for each flare. 

(C) The following information regarding pilot and purge gas for each 

flare: 

(i) Type(s) of gas used; 

(ii) Actual set operating flow rate in standard cubic feet per 

minute; 

(iii) Maximum total sulfur concentration expected for each type 

of gas used; and 

(iv) Average higher (gross) heating value expected for each 

type of gas used. 

1118 - 11 
Rule 1118 (Cont.) (Amended November 4, 2005) 

(D) Drawing(s), preferably to scale with dimensions, and an as built 

process flow diagram of the flare(s) identifying major components, 

such as flare header, flare stack, flare tip(s) or burner(s), purge gas 

system, pilot gas system, ignition system, assist system, water seal, 

knockout drum and molecular seal. 

(E) A representative flow diagram showing the interconnections of the 

flare system(s) with vapor recovery system(s), process units and 

other equipment as applicable. 

(F) A complete description of the assist system process control, flame 

detection system and pilot ignition system. 

(G) A complete description of the gas flaring process for an integrated 

gas flaring system which describes the method of operation of the 

flares (e.g. sequential, etc.). 

(H) A complete description of the vapor recovery system(s) which 

have interconnection to a flare, such as compressor description(s), 

design capacities of each compressor and the vapor recovery 

system, and the method currently used to determine and record the 

amount of vapors recovered. 

(I) Drawing(s) with dimensions, preferably to scale, showing the 

following information for proposed vent gas: 

(i) Sampling locations; and, 

(ii) Flow meter device, on/off flow indicators, higher heating 

value analyzer and total sulfur analyzer locations and the 

method used to determine the location. 

(J) A detailed description of manufacturer’s specifications, including 

but not limited to, make, model, type, range, precision, accuracy, 

calibration, maintenance, a quality assurance procedure and any 

other specifications and information referenced in Attachment A 

for all existing and proposed flow metering devices, on/off flow 

indicating devices, higher heating value and total sulfur analyzers 

for vent gas. 

(K) A complete description and the data used to determine and to set 

the actuating and deactuating and the method to be used for 

verification of each setting for each on/off flow indicator. 

(L) A complete description of proposed analytical and sampling 

methods or estimation methods, if applicable, for determining 

1118 - 12 
Rule 1118 (Cont.) (Amended November 4, 2005) 

higher (gross) heating value and total sulfur concentration of the 

flare vent gas. 

(M) A complete description of the proposed data recording, collection 

and management and any other specifications and information 

referenced in Attachment A for each flare monitoring system. 

(N) A complete description of proposed method to determine, monitor 

and record total volume, higher heating value and total sulfur 

concentration of gases vented to a flare for each flare event 

pursuant to the requirements of this rule. 

(O) A schedule for the installation and operation of each flare 

monitoring system. 

 (P) A complete description of any proposed alternative criteria to 

determine a sampling flare event for each specific flare, if any, and 

detailed information used for the basis of establishing such criteria. 

(Q) A request to use the alternative sampling program pursuant to 

subparagraph (g)(4)(C), if applicable, with a complete description 

of proposed Quality Assurance/Quality Control procedures to be 

used in a test program to determine the correlation between the 

results from the alternative sampling program and the testing and 

monitoring methods specified in subdivision (j). 

(g) Operation Monitoring and Recording Requirements 

The owner or operator of a flare subject to this rule shall comply with the 

following: 

(1) On or before six (6) months after approval of the Flare Monitoring and 

Recording Plan or Revised Flare Monitoring and Recording Plan, , start 

monitoring and recording in accordance with subdivision (g), in 

accordance with the approved Flare Monitoring and Recording Plan or 

Revised Flare Monitoring and Recording Plan. 

(2) Notwithstanding the provisions in Rule 430 - Breakdown Provisions and 

Rule 2004 - Requirements, the Operation Monitoring and Recording 

Requirements of this rule shall be applicable during all periods including 

breakdowns except as specified in subparagraph (g)(5)(A). 

(3) Perform monitoring and recording of the operating parameters, as 

applicable, according to the monitoring and recording requirements and 

1118 - 13 
Rule 1118 (Cont.) (Amended November 4, 2005) 

frequency shown in Table 1 (including footnotes) below, except as 

specified in paragraph (g)(4) and (g)(5). 

TABLE 1 

Effective until June 30, 2007

TYPE OF 

FLARE 

OPERATING 

PARAMETER 

MONITORING 

AND RECORDING

Gas Flow1

Measured and Recorded2

Continuously with Flow Meter(s) 

and/or On/Off Flow Indicator(s) 

Gas Higher Heating 

Value 3 Calculated or Representative 

Sample for Each Flare Event4

Clean Service 

Total Sulfur 

Concentration5 Calculated or Representative 

Sample for Each Flare Event 

Gas Flow1

Measured and Recorded2

Continuously with Flow Meter(s) 

and/or On/Off Flow Indicator(s) 

Gas Higher Heating 

Value 

One Daily Representative Sample 

for a Flare Event and a 

Representative Sample for Each 

Sampling Flare Event4; or

Continuously Measured and 

Recorded with a Higher Heating 

Value Analyzer 

Emergency 

Service 

Total Sulfur 

Concentration5

One Daily Representative Sample 

for a Flare Event and a 

Representative Sample for Each 

Sampling Flare Event4

; or SemiContinuously Measured and 

Recorded with a Total Sulfur 

Analyzer 

Gas Flow1

Measured and Recorded2

Continuously with Flow Meter(s) 

with or without on/off flow 

indicator(s) 

General 

Service 

Gas Higher Heating 

Value 3

One Daily Representative Sample 

for a Flare Event and a 

Representative Sample for Each 

Sampling Flare Event4

; or

Continuously Measured and 

Recorded with a Higher Heating 

Value Analyzer 

1118 - 14 
Rule 1118 (Cont.) (Amended November 4, 2005) 

TYPE OF 

FLARE 

OPERATING 

PARAMETER 

MONITORING 

AND RECORDING

General 

Service 

Total Sulfur 

Concentration5

One Daily Representative Sample 

for a Flare Event and a 

Representative Sample for Each 

Sampling Flare Event4; or SemiContinuously Measured and 

Recorded with a Total Sulfur 

Analyzer 

1. Standard Cubic Feet per Minute. 

2. All flow meters, flow indicators and recorders shall meet or exceed the minimum 

specifications listed below upon rule adoption or those in Attachment A by January 1, 

2007: 

 (i) Velocity Range: 1-250 ft/sec 

 (ii) Repeatability: ± 1% of reading over the velocity range 

 (iii) Accuracy: ± 5% of reading over the velocity range 

 (iv) Installation: Applicable AGA, ANSI, API, or equivalent standard; 

hot tap capability. 

 (v) Flow Rate Determination Applicable AGA, ANSI, API, or equivalent standard. 

3. Higher (Gross) Heating Value in British Thermal Units per Standard Cubic Foot. 

4. Sample shall be taken within 30 minutes of the start of each flare event. Only one 

representative sample is required each day for flare events that are not sampling flare 

events. A representative sample collected for a sampling flare event on that day may be 

used to satisfy this requirement. Sampling flare events that occur within 15 minutes of 

each other are considered a single event if the facility can demonstrate to the satisfaction 

of the Executive Officer that the events had a common cause and the release of vent gas 

originated from the same process unit. For flare events lasting 15 minutes or less, no 

representative sample is required and emission shall be calculated according to the 

procedure in Attachment B Section 1 Note (2). A sample shall not be required if the 

operator demonstrates vent gas is not routed to a flare based on verifiable records of flare 

water seal level and/or other parameters as approved by the Executive Officer in the Flare 

Monitoring and Recording Plan or the Revised Flare Monitoring and Recording Plan. 

The requirement for daily representative sample shall be effective January 1, 2006. 

5. Total Sulfur as SO2, ppm. 

Effective July 1, 2007 

TYPE OF 

FLARE 

OPERATING 

PARAMETER 

MONITORING 

AND RECORDING

Gas Flow1

Measured and Recorded2

Continuously with Flow Meter(s) 

and/or On/Off Flow Indicator(s) 

Gas Higher Heating 

Value 3 Calculated or Representative Sample 

for Each Flare Event 

Clean Service 

Total Sulfur 

Concentration4 Calculated or Representative Sample 

for Each Flare Event 

1118 - 15 
Rule 1118 (Cont.) (Amended November 4, 2005) 

TYPE OF 

FLARE 

OPERATING 

PARAMETER 

MONITORING 

AND RECORDING

Gas Flow1

Measured and Recorded2

Continuously with Flow Meter(s) 

and/or On/Off Flow Indicator(s) 

Gas Higher Heating 

Value 3

Continuously Measured and 

Recorded with a Higher Heating 

Value Analyzer 

Emergency 

Service 

Total Sulfur 

Concentration4

Semi-Continuously Measured and 

Recorded with a Total Sulfur 

Analyzer 

Gas Flow1

Measured and Recorded2

Continuously with Flow Meter(s) 

with or without on/off flow 

indicator(s) 

Gas Higher Heating 

Value 3

Continuously Measured and 

Recorded with a Higher Heating 

Value Analyzer 

General Service 

Total Sulfur 

Concentration4

Semi-Continuously Measured and 

Recorded with a Total Sulfur 

Analyzer 

1. Standard Cubic Feet per Minute. 

2. All flow meters, flow indicators and recorders shall meet or exceed the minimum 

specifications in Attachment A. 

3. Higher (Gross) Heating Value in British Thermal Units per Standard Cubic Foot. 

4. Total Sulfur as SO2, ppm. 

(4) Alternative Flare Vent Gas Sampling 

(A) In cases where sampling of vent gas is exempted pursuant to 

paragraph (k)(1), the owner or operator of a gas flare shall identify 

for each flare event, the cause of event, the process system(s) 

involved, date and time event started and duration and any other 

information related to the type of vent gas (e.g. total sulfur 

concentration) which is necessary to calculate flare emissions 

using the guidelines in Appendix B for substituted data. The 

estimated emissions, subject to approval by the Executive Officer 

as representative of emissions from that flare event, shall be 

reported and submitted with the quarterly report as specified in 

paragraph (i)(4). 

1118 - 16 
Rule 1118 (Cont.) (Amended November 4, 2005) 

(B) The owner or operator of a flare may comply with the vent gas 

sampling requirements of paragraph (g)(3) based on alternative 

criteria for determining a sampling flare event for each specific 

flare, provided that such alternative criteria are submitted as part of 

the Flare Monitoring and Recording Plan in subparagraph 

(f)(3)(P), and are approved in writing by the Executive Officer. 

(C) During the interim period, which is after the approval of the Flare 

Monitoring and Recording Plan or Revised Flare Monitoring and 

Recording Plan and until in compliance with paragraph (g)(1), an 

alternative sampling program for sampling flare events for each 

flare may be used provided the following requirements are met: 

(i) A request to use an alternative sampling program has been 

submitted by the flare owner or operator as part of the Flare 

Monitoring and Recording Plan pursuant to subparagraph 

(f)(3)(Q) and approved as equivalent by the Executive 

Officer. The Executive Officer must make a finding, in the 

case of an existing facility, that compliance with 

subparagraph (f)(1)(B) is not feasible. 

(ii) The vent gas(es) to each flare shall be sampled and 

analyzed, if applicable, for total sulfur and higher (gross) 

heating value in accordance with methods specified in 

subdivision (j), once a day. If there is a sampling flare 

event in any day, the sampling and analysis shall also be 

conducted during such event in addition to the daily 

sampling requirement. 

(iii) In addition to the samples collected and analyzed pursuant 

to the requirements in clause (g)(4)(C)(ii), the vent gas(es) 

to each flare shall be sampled and analyzed in accordance 

with Table 1, as follows: 

(I) Once a day during each sampling flare event other 

than the flare event specified in clause (g)(4)(C)(ii), 

if such a sampling event occurs during that day.(II)

 For all sampling flare events that are the 

result of any process unit shutdown. 

(iv) The vent gas(es) to each flare shall be sampled and 

analyzed for all other sampling flare events to measure 

1118 - 17 
Rule 1118 (Cont.) (Amended November 4, 2005) 

hydrogen sulfide concentrations in the vent gas using a 

colorimetric method or other methods as specified in the 

Flare Monitoring and Recording Plan pursuant to 

subparagraph (f)(3)(Q) and as approved in writing by the 

Executive Officer. 

(D) After the interim period of monitoring and recording pursuant to 

subparagraph (g)(4)(C), the owner or operator of a flare may, 

based on the monitoring data, request a change in the vent gas 

sampling requirement of paragraph (g)(3) and/or propose an 

equivalent alternative criteria for determining a sampling flare 

event for each specific flare, provided that the owner or operator of 

the flare submits an application for the modification to the Flare 

Monitoring and Recording Plan and can demonstrate, and obtain 

written approval of the Executive Officer that an alternative vent 

gas sampling and/or an alternative criteria for determining a 

sampling flare event for each specific flare is equivalent to the 

sampling requirement of paragraph (g)(3) and is adequate to 

determine the quality of vent gas(es) and to calculate emissions 

from all such flare events. 

(E) After the interim period of monitoring and recording pursuant to 

subparagraph(g)(4)(C), the Executive Officer may revise any 

alternative criteria for determining a sampling flare event for each 

specific flare or any alternative vent gas sampling which have been 

previously proposed by the owner or operator of a flare and 

approved by the Executive Officer, if the Executive Officer 

determines that the alternative(s) is not adequate based on the 

monitoring data or other information to determine the quality of 

vent gas(es) and to calculate emissions from all such flare events. 

The owner or operator of the flare shall use the revised criteria for 

determining a sampling flare event or vent gas sampling to monitor 

and record flare events no later than 30 days after written 

notification by the Executive Officer. 

(5) Flare Monitoring System 

(A) Maintain any flare monitoring system, used to ensure compliance 

with paragraph (g)(3) of this rule, in good operating condition at 

1118 - 18 
Rule 1118 (Cont.) (Amended November 4, 2005) 

all times when the flare that it serves is operational, except when 

out of service due to: 

(i) Breakdowns and unplanned system maintenance, which 

shall not exceed 96 hours, cumulatively, per quarter for 

each reporting period; or, 

(ii) Planned maintenance, which shall not exceed 14 days per 

18 month period commencing the start of flare monitoring 

and recording, provided that a written notification detailing 

the reason for maintenance and methods that will be used 

during the maintenance period to determine emissions 

associated with flare events is provided to the Executive 

Officer prior to, or within 24 hours of, removal of the 

monitoring system from service. 

(B) A flare monitoring system may be used to measure and record the 

operating parameters required in paragraph (g)(3) of this rule for 

more than one flare provided that: 

(i) All the gases being measured and recorded are delivered to 

the flare(s) for combustion; and, 

(ii) Effective July 1, 2007, if the flare monitoring system is 

used to measure and record the operating parameters for 

emergency service flares, as well as general service flares, 

the flare monitoring system shall consist of a continuous 

vent gas flow meter, a continuous higher heating value 

analyzer, a total sulfur analyzer and recorder that meet the 

requirements specified in Attachment A. 

(6) Monitor the presence of a pilot flame using a thermocouple or any other 

equivalent device approved by the Executive Officer to detect the 

presence of a flame. 

(7) Effective July 1, 2006, monitor all flares for visible emissions using color 

video monitors with date and time stamp, capable of recording a digital 

image of the flare and flame at a rate of no less than one frame per minute. 

(8) Effective January 1, 2007, for all emergency and general service flares: 

(A) Install each flow meter in a manner and at a location that would 

allow for accurate measurements of the total volume of vent gas to 

each flare. If the flow meter cannot be placed in the location that 

would allow for accurate measurement due to physical constraints, 

1118 - 19 
Rule 1118 (Cont.) (Amended November 4, 2005) 

the operator shall retrofit or equip the existing flow meters with 

totalizing capability to indicate the true net volume of gas flow to 

each flare. 

(B) Install an automated sample collection system at each flare, 

capable to alert personnel that a sample is being collected 

following the start of a sampling flare event, unless total sulfur is 

monitored with a certified analyzer approved by the Executive 

Officer. 

(C) Monitor and record the pilot gas and purge gas flow to each flare 

using a flow meter or equivalent device approved by the Executive 

Officer. 

(h) Recordkeeping Requirements 

The owner or operator of a flare shall maintain records in a manner approved by 

the Executive Officer for all the information required to be monitored and make 

such records available to the Executive Officer upon request: 

(1) For a period of 90 days for the information required under paragraph 

(g)(7); and 

(2) For a period of five (5) years for all the information required under 

paragraphs (g)(3), (g)(4), (g)(5), (g)(6) and subparagraph (g)(8)(C) as 

applicable. 

(i) Notification and Reporting Requirements 

Effective January 1, 2006, the owner or operator of a flare shall: 

(1) Provide a 24 hour telephone service for access by the public for inquiries 

about flare events. The owner or operator shall provide the Executive 

Officer in writing the name and number of the initial contact and any 

contact update. 

(2) Notify the Executive Officer by telephone within one hour of any 

unplanned flare event with emissions exceeding either 100 pounds of 

VOC or 500 pounds of sulfur dioxide, or exceeding 500,000 standard 

cubic feet of flared vent gas, and 

(3) Submit a Specific Cause Analysis as required by subparagraph (c)(1)(D) 

to the Executive Officer within 30 days, identifying the cause and duration 

of the unplanned flare event, and any mitigation and corrective actions 

1118 - 20 
Rule 1118 (Cont.) (Amended November 4, 2005) 

taken. The owner or operator may request the Executive Officer to grant 

an extension of up to 30 days to submit the Specific Cause Analysis. 

(4) Notify the Executive Officer at least 24 hours prior to the start of a 

planned flare event with emissions exceeding either 100 pounds of VOC 

or 500 pounds of sulfur dioxide, or 500,000 standard cubic feet of 

combusted vent gas. 

(5) Submit a quarterly report in an electronic format approved by the 

Executive Officer within 30 days after the end of each quarter. Each 

quarterly report shall be certified for accuracy in writing by the 

responsible facility official and shall include the following: 

(A) The information required to be monitored under paragraph (g)(3), 

(g)(4), (g)(5), d (g)(6) and subparagraph (g)(8)(C) of this rule. 

(B) The total daily and quarterly emissions of criteria pollutants from 

each flare and each flare event along with all information used to 

calculate the emissions, which includes standard volumes, higher 

heating values and total sulfur concentration of the vent gases, 

event duration and emission factors. Identify each reported value 

of flow rate, higher heating values or sulfur concentration reported 

using Data Substitution Procedures in Attachment B, and identify 

the data substitution method used and the date the method was 

approved by the Executive Officer, if applicable. 

(i) Emissions from flares shall be calculated using the 

Emissions Calculation Procedures outlined in Attachment 

B: Guidelines for Emissions Calculations. 

(ii) During all down time periods of the monitoring system, 

emissions shall be calculated using the Missing Data 

Substitution Procedures outlined in Attachment B: 

Guidelines for Emissions Calculations. 

(C) The description of the cause of each flare event as analyzed 

pursuant to subparagraphs (c)(1)(D) and (c)(1)(E) and the category 

of flare event such as emergency, shutdown, startup or essential 

operational need or other specific cause(s), and the associated 

emissions. 

(D) Records of annual acoustical or temperature leak survey conducted 

pursuant to subparagraph (c)(1)(C). The record shall include 

1118 - 21 
Rule 1118 (Cont.) (Amended November 4, 2005) 

identification of all valves inspected, date of inspections, and the 

name of the person(s) conducting the inspections. 

(E) Flare monitoring system downtime periods, including dates and 

times and explanation for each period. 

(F) A copy of written notices for all reportable air releases related to 

any flare event, as required by 40 CFR, Part 302 - Designation, 

Reportable Quantities, and Notification and 40 CFR, Part 355 - 

Emergency Planning and Notification, if applicable. 

(j) Testing and Monitoring Methods 

(1) For the purpose of this rule, the test methods listed below shall be used. 

Alternative test methods may be used if it is determined to be equivalent 

and approved in writing by the Executive Officer, and, if applicable by the 

California Air Resources Board, and the U.S. Environmental Protection 

Agency. 

(A) The higher (gross) heating value of vent gases shall be determined 

by: 

(i) ASTM Method D 2382-88, ASTM Method D 3588-91 or 

ASTM Method D 4891-89, and 

(ii) Effective July 1, 2007, with a higher heating value analyzer 

that meets or exceeds the specifications in Attachment A. 

(B) The total sulfur concentration, expressed as sulfur dioxide, shall be 

determined by: 

(i) District Method 307-91 or ASTM Method D 5504-01, and 

(ii) Effective July 1, 2007, with a total sulfur analyzer that 

meets or exceeds the specifications in Attachment A. 

(C) The gas flow shall be determined by a flow measuring device that 

meets or exceeds the specifications described in Attachment A, as 

applicable. The accuracy of all flow meters shall be verified every 

twelve months according to the manufacturers’ procedures and the 

results shall be submitted to the Executive Officer within 30 days 

after the reports are issued. 

(2) Until the continuous and semi-continuous analyzers are certified by the 

Executive Officer and operational, analyses for higher (gross) heating 

value and total sulfur concentration shall be: 

(A) Conducted by a District approved lab; or 

1118 - 22 
Rule 1118 (Cont.) (Amended November 4, 2005) 

(B) Conducted by the owner or operator of a gas flare if the District 

has provided prior written approval of QA/QC and standard 

operating procedures. All analytical reports shall be signed by the 

facility official responsible for analytical equipment to certify the 

accuracy of the reports. 

(3) Visible emissions pursuant to subparagraph (c)(1)(B) shall be determined 

by US EPA Method 22, 40 CFR Part 60 Appendix A. 

(4) Notwithstanding paragraph (j)(1) and (j)(2), continuous monitoring 

systems certified under Rule 2011 - Requirements for Monitoring, 

Reporting and Recordkeeping of Oxides of Sulfur (SOx) Emissions and 

Rule 2012 - Requirements for Monitoring, Reporting and Recordkeeping 

of Oxides of Nitrogen (NOx) Emissions may be used for the monitoring of 

vent gases. 

(k) Exemptions 

(1) Notwithstanding a flare monitoring system, consisting of a flow meter, 

higher heating value analyzer and total sulfur analyzer that is in operation, 

sampling and analyses of representative samples for higher heating values 

and total sulfur concentration pursuant to paragraph (g)(3) may not be 

required for any flare event that: 

(A) Is a result of a catastrophic event including a major fire or an 

explosion at the facility such that collecting a sample is infeasible 

or constitutes a safety hazard, or 

(B) Constitutes a safety hazard to the sampling personnel at the 

sampling location approved in the Flare Monitoring and Recording 

Plan during the entire flare event, provided that a sample is 

collected at an alternative location where it is safe as determined 

by the facility owner or operator. The owner or operator shall 

demonstrate to the Executive Officer that the sample collected at 

an alternative location is representative of the flare event. 

(2) Any sulfur dioxide emissions from flaring events caused by external 

power curtailment beyond the operator’s control, (excluding interruptible 

service agreements), natural disasters or acts of war or terrorism shall not 

count towards the performance targets specified in subdivision (d) upon 

submittal of documentation proving the existence of such events and 

1118 - 23 
Rule 1118 (Cont.) (Amended November 4, 2005) 

certified in writing by the petroleum refinery official responsible for 

emission reporting. 

1118 - 24 
Rule 1118 (Cont.) (Amended November 4, 2005) 

ATTACHMENT A 

FLARE MONITORING SYSTEM REQUIREMENTS 

The components of each flare monitoring system must meet or exceed the minimum 

specifications listed below. Components with other specifications may be used provided 

the owner or operator of a gas flare can demonstrate that the specifications are equivalent 

and has been approved by the Executive Officer. 

1. Continuous Flow Measuring Device 

The monitor must be sensitive to rapid flow changes, and have the capability of 

reporting both instantaneous velocity and totalized flow. Materials exposed to the 

flare gas shall be corrosion resistant. If required by the petroleum refinery or the 

hydrogen production plant, the manufacturer must provide an enclosure with an 

area classification rating of Class 1, Division 2, Groups A, B, C, D, and is FM and 

CSA approved. The monitor shall (i) feature automated daily calibrations at low 

and high ranges, and (ii) shall signal alarms if the calibration error or drift is 

exceeded, provided that the monitor is equipped with such capability. The 

volumetric flow measuring device may consist of one or more flow meters, and, 

as combined, shall meet the following specifications. 

Velocity Range: 0.1-250 ft/sec 

Repeatability: ± 1% of reading over the velocity range 

Accuracy: + 20% of reading over the velocity range of 0.1-1 

ft/s and ± 5% of reading over the velocity range of 

1-250 ft/s 

Installation: Applicable AGA, ANSI, API, or equivalent 

standard; hot tap capability. If applicable, the 

manufacturer must specify the straight-run pipe 

requirements in terms of the minimum upstream and 

downstream distances from the nearest flow 

disturbances to the device 

Flow Rate 

Determination: 

Must be corrected to one atmosphere pressure and 

680 F and recorded as one-minute averages 

Data Records Measured continuously and recorded over oneminute averages. The instrument shall be capable of 

storing or transferring all data for later retrieval 

QA/QC Shall comply with the flow QA/QC requirements of 

District Rule 218.1. An annual verification of 

accuracy is required, and shall be specified by the 

manufacturer. Note: A flow RATA is generally 

infeasible due to safety concerns 

2. On/Off Flow Indicator 

The on/off flow indicator is a device which is used to demonstrate the flow of vent 

gas during a flare event, and shall meet or exceed specifications as approved by the 

Executive Officer. The on/off flow indicator setting shall be verifiable. 

1118 - 25 
Rule 1118 (Cont.) (Amended November 4, 2005) 

3. Data Recording System 

All data as generated by the above flow meters and the on/off flow indicators must 

be continuously recorded by strip chart recorders or computers. The strip chart 

must have a minimum chart width of 10 inches, a readability of 0.5% of the span, 

and a minimum of 100 chart divisions. The computer must have the capability to 

generate one-minute average data from that which is continuously generated by the 

flow meters and the on/off limit switch. 

4. Continuous and Semi-continuous Gaseous Stream Higher Heating Value 

(HHV) Flare Monitoring Systems 

The following is intended to ensure that verifiable, meaningful, and representative 

data are collected from continuous and semi-continuous gaseous stream HHV flare 

measurement monitoring devices systems. All procedures are subject to Executive 

Officer review and approval. 

General Requirements: 

a. The monitoring system must be capable of measuring HHV within the 

requirements of the rule. 

b. The monitoring system must be capable of adjusting to rapid changes in 

HHV within a reasonable time meeting the definition of a continuous or 

semi-continuous monitoring system as defined in the applicable rule and 

as approved by the Executive Officer. 

c. Monitoring system sampling interfaces and analyzers in contact with 

sample gas must be compatible with sample gases and able to resist flow 

temperatures and pressures. 

d. The sampling inlet system interface must be heated as necessary so as to 

prevent condensation. 

e. Sample gas must be conditioned such that the sample is free of particulate 

or liquid matter. 

f. The sample must flow without impediment through the instrument 

sampling system sampling interface and analyzer. 

g. Use an enclosure with an area classification rating of Class 1, Division 2, 

Groups A, B, C, D, and is FM or CSA approved. The enclosure must be 

able to maintain a stable analyzer temperature as required for analyzer 

performance. 

h. The monitoring system must feature automated daily calibrations 

calibration checks, minimally at mid-range, and preferably at both 

applicable Federal minimum BTU requirements (low end) and 95% of full 

scale (high end) ranges at low and high ranges 

i. The monitoring system system analyzer must include an output 

compatible with a Data Acquisition System (DAS) or similar system that 

can process data generated by the analyzer and record the results. A data 

recorder compatible with analyzer output and capable of recording 

analyzer output must be supplied with the instrument. 

1118 - 26 
Rule 1118 (Cont.) (Amended November 4, 2005) 

j. Each monitoring system must have a written quality assurance/quality 

control (QA/QC) plan approved by the Executive Officer and available for 

District inspection. 

k. Maintain a maintenance log for each monitoring system. 

l. Perform routine maintenance and repair as recommended by the 

manufacturer or according to a standard operating procedure submitted 

and approved by the Executive Officer. 

m. The placement and installation of monitoring systems is critical for 

collecting representative information on HHV gas content. Factors that 

should be considered in placement of a sampling interface include but are 

not limited to safety, ensuring the sample is representative of the source, 

ease of placement and access. Sampling interfaces, conditioning systems 

and enclosures may be shared with other instrumentation, if appropriate. 

n. Perform at monitoring system start-up and on an annual basis a relative 

accuracy test audit (RATA) which is the ratio of the sum of the absolute 

mean difference between the monitoring system generated data and the 

value determined using ASTM D1945-03 and ASTM D3588-91, ASTM D 

4891-89, or other ASTM standard as approved by the Executive Officer. 

See rule 218 (a)(23) for calculations. 

o. Periodically perform a calibration curve or linearity verification error test 

according to permitting conditions and or on a schedule approved by the 

Executive Officer. Typically, this calibration curve will be prepared from 

standards representing a: 

i. 10-30 percent of the measurement range 

ii. 40-60 percent of the measurement range 

iii. 80-100 percent of the measurement range 

p. Analyzers with auto calibration check capability should be checked daily 

unless a different calibration frequency is approved by the Executive 

Officer. For analyzers without auto calibration check capability, submit a 

calibration check frequency request including supporting documentation 

to the Executive Officer for comment and approval. 

q. Periodically perform a zero drift test. Allowed zero drift should be 

consistent with a properly operating system. See rule 218(a)(32) for 

calculations. 

r. Retain records on the valid data return percentage. 

s. Retain records on the availability or up-time of the monitoring system. 

t. Retain records on the breakdown frequency and duration of the 

breakdown. 

u. Retain records on excursions beyond quality control limits stated in the 

QA plan. 

1118 - 27 
Rule 1118 (Cont.) (Amended November 4, 2005) 

5. Continuous and Semi-continuous Gaseous Stream Total Sulfur Monitoring 

Systems 

The following is intended to ensure that verifiable, meaningful, and representative 

data are collected from continuous and semi-continuous gaseous stream sulfur 

monitoring systems. All procedures are subject to Executive Officer review and 

approval. 

General Requirements 

a. The monitoring system must be capable of measuring total sulfur 

concentration within the requirements of the rule. 

b. The monitoring system must be capable of adjusting to rapid changes in 

sulfur concentration within a reasonable time as defined in the applicable 

rule and as approved by the Executive Officer. 

c. Monitoring system in contact with sample gas must be inert to sulfur gases 

and resistant to corrosion. 

d. The sampling inlet system interface system must be heated as necessary so 

as to prevent condensation. 

e. Sample gas must be conditioned such that the sample is free of particulate 

or liquid matter. 

f. The sample must flow without impediment through the instrument 

sampling system sampling interface and analyzer. 

g. Use an enclosure with an area classification rating of Class 1, Division 2, 

Groups A, B, C, D, and is FM or CSA approved. The enclosure must be 

able to maintain a stable analyzer temperature as required for analyzer 

performance. 

h. The monitoring system must feature automated daily calibrations at low 

and high ranges, and shall signal alarms if the calibration error or drift is 

exceeded. 

i. The monitoring system must include a Data Acquisition System (DAS) or 

similar system that can process data generated by the analyzer and record 

the results. 

j. Each monitoring system must have a written quality assurance/quality 

control (QA/QC) plan approved by the Executive Officer and available for 

District inspection. 

k. Maintain a maintenance log for each monitoring system. 

l. Perform routine maintenance as recommended by the manufacturer or 

according to a standard operating procedure submitted and approved by 

the Executive Officer. 

m. The placement and installation of monitoring systems is critical for 

collecting representative information on total sulfur gas concentration. 

Factors that should be considered in placement of a sampling interface 

include but are not limited to safety, ensuring the sample is representative 

1118 - 28 
Rule 1118 (Cont.) (Amended November 4, 2005) 

of the source, ease of placement and access. Sampling interfaces, 

conditioning systems and enclosures may be shared with other 

instrumentation, if appropriate. 

n. Perform at monitoring system start-up and on an annual basis a relative 

accuracy test audit (RATA) which is the ratio of the sum of the absolute 

mean difference between the monitoring system generated data and the 

value determined using SCAQMD Laboratory Method 307-91, ASTM 

D5504-01 or other ASTM standard as approved by the Executive Officer. 

See rule 218(a)(23) for calculations. 

Note: Facilities are reminded that there are many critical issues for the 

collection of representative and monitoring system comparable gas 

samples destined for Method 307-91 or ASTM D5504-01 analysis. 

o. Facilities are strongly encouraged to use calibration gases prepared using a 

NIST hydrogen sulfide SRM, Nederlands Meetinstituut NMi or a NTRM 

standard as the primary reference. 

p. Periodically perform a calibration curve or linearity verification performed 

according to permitting conditions and/or on a schedule approved by the 

Executive Officer. Typically, this calibration curve will be prepared from 

standards representing: 

i. 10 to 30 percent of the measurement range 

ii. 40 to 60 percent of the measurement range 

iii. 80 to 100 percent of the measurement range 

q. Analyzers with auto calibration capability shall be calibrated daily unless 

a different calibration frequency is approved by the Executive Officer. 

For analyzers without auto calibration capability, submit a calibration 

frequency request, including supporting documentation to the Executive 

Officer for comment and approval. 

r. Seven Day Calibration Error Test shall be performed by evaluating the 

analyzer performance over seven consecutive days as necessary. The 

calibration drift should not exceed five percent of the full-scale range. 

s. Analyze daily a control or drift test sample or standard. Adequate system 

analyzer performance is demonstrated by recoveries of 90 to 110 percent 

of the theoretical amounts for total reduced sulfur species in the test gas. 

t. Periodically perform an analyzer blank test to evaluate the presence of 

analyzer leaks or wear on sample valves and related components. Replace 

components as necessary to restore the analyzer to nominal function. A 

blank should yield results below the monitoring plan approved lower 

measurement range. 

u. Periodically perform a zero drift test. Allowed zero drift should be 

consistent with a properly operating system analyzer. See rule 218(a)(32) 

for calculations. 

v. Retain records on the valid data return percentage. 

w. Retain records on the availability or up-time of the monitoring system. 

1118 - 29 
Rule 1118 (Cont.) (Amended November 4, 2005) 

x. Retain records on the breakdown frequency and duration of the 

breakdown. 

y. Retain records on excursions beyond quality control limits stated in the 

QA plan. 

Gas Chromatograph (GC) Based System Analyzer Specific Requirements 

a. The following performance tests specific to GC based sulfur analyzers are 

part of an overall QA program. This list is not all inclusive. The specific 

performance tests that are required under rule compliance will be based 

upon analyzer configuration, data requirements, practical concerns such as 

safety and are subject to approval by the Executive Officer. 

i. Whenever a calibration is performed and whenever a calibration 

drift test is performed, examine retention times for each calibration 

component. Compare the retention times against historically 

observed retention times. Retention time drift should be better 

than within five percent. Compare the retention times to analyzer 

and DAS parameters such as time gates to ensure compatibility. 

These parameters including the analysis time may need to be 

updated on occasion. 

ii. Verify daily that the analyzer response drift for individual sulfur 

species does not exceed ten percent of the control information. 

Total Sulfur Analyzer System Requirements 

a. The following performance tests specific to total sulfur based analyzers 

are part of an overall QA program. This list is not all inclusive. The 

specific performance tests that are required under rule compliance will be 

based upon instrument analyzer configuration, data requirements, practical 

concerns such as safety and are subject to approval by the Executive 

Officer. 

i. Verify daily that the analyzer response drift for the concentration 

of total sulfur, expressed as sulfur dioxide does not exceed ten 

percent of the control information. 

1118 - 30 
ATTACHMENT B 

GUIDELINES FOR CALCULATING FLARE EMISSIONS

The following methods shall be used to calculate flare emissions. An alternative method 

may be used, provided it has been approved as equivalent in writing by the Executive 

Officer. 

1. Emission Calculation Procedures 

Petroleum refinery, sulfur recovery plant or hydrogen production facility operators shall 

use the following equations and emission factors to calculate emissions from vent gas, 

natural gas, propane and butane: 

Vent Gas 

Air Pollutant Equation Emission Factor 

ROG E = V x HHV x EF 0.063 lb/mmBTU 

NOx E = V x HHV x EF 0.068 lb/mmBTU 

CO E = V x HHV x EF 0.37 lb/mmBTU 

PM10 E = V x EF 21 lb/mmSCF 

SOx E = V x Cs x 0.1662 Note (1) 

Where: 

E = Calculate vent gas emissions (lbs) 

V= Volume flow of vent gas, as measured in million standard cubic foot at 14.7 

psia and 680 Fahrenheit 

HHV = Higher Heating Value, as measured in British Thermal Unit per 

standard cubic foot 

EF = Emission Factor 

Cs = The concentration of total sulfur in the vent gas, expressed as sulfur 

dioxide, as measured in part per million by volume using the methods 

specified in this rule. 

Note (1) If an approved total sulfur analyzer is used in accordance with this rule, Cs is 

the concentration of total sulfur in the vent gas, averaged over 15 minutes or 

less, if the event duration is shorter than 15 minutes. 

Note (2) For a flare event where a representative sample or other sampling method is not 

required pursuant to Table 1 of this rule, use HHV and/or Cs from any 

representative sample of a flare event on the same day. If no representative 

sample is taken that day, use HHV and/or Cs from the last representative 

sample taken prior to the flare event. 

Natural Gas 

Air Pollutant Equation Emission Factor (lb/mmSCF)

ROG E = V x EF 7 

NOx E = V x EF 130 

CO E = V x EF 35 

PM10 E = V x EF 7.5 

SOx E = V x EF 0.83 

1118 - 31 
Rule 1118 (Cont.) (Amended November 4, 2005) 

Propane and Butane 

Air Pollutant Equation Emission Factor 

(lb/mmBTU) 

ROG E = V x 3500 x EF 0.003 

NOx E = V x 3500 x EF 0.13 

CO E = V x 3500 x EF 0.032 

PM10 E = V x 3500 x EF 0.0014 

SOx E = V x 3500 x EF 0.047 

Single On/Off Flow Indicator Switch 

The flow rate setting of the on/off flow indicator switch if the switch is not actuated 

or the maximum design capacity of the flare for the flow rate for each flare event. 

Multiple On/Off Flow Indicator Switch 

a) The flow rate setting of the first stage on/off flow indicator switch if the 

switch is not actuated. 

b) When an on/off switch is actuated assume the flow rate is the flow rate that 

would actuate the on/off switch set at the next highest flow rate. 

c) Use the maximum design capacity of the flare for the flow rate when the 

on/off switch set for the highest flow rate is actuated. 

Flow Meters Only 

a) Use the recorded flow meter data until the maximum range is exceeded. 

b) When the maximum range of the flow meter is exceeded, assume the flow rate 

is the maximum design capacity of the flare(s), unless the owner or operator 

demonstrates and the Executive Officer approves a calculated flow based 

upon operational parameters and process data that represent the flow during 

the period of time that the flow exceeded the maximum range of the flow 

meter. 

c) When the flow rate is below the valid lower range of the flow meter, assume 

the flow rate is at the lower range. 

Combination of Flow Meters and On/Off Flow Indicator Switches 

a) Use the recorded flow meter data until the maximum range is exceeded. 

b) When the maximum range of the flow meter is exceeded, assume the flow rate 

is the flow rate that would actuate the on/off switch set at the next highest 

flow rate. 

c) Use the maximum design capacity of the flare for the flow rate when the 

on/off switch set for the highest flow rate is actuated. 

d) When the flow rate is below the valid lower range of the flow meter, assume 

the flow rate is at the lower range. 

e) When the flow rate is below the valid lower range of the flow meter and the 

set flow rate of an on/off switch, assume the flow rate is the flow rate that 

would actuate the on/off switch. 

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Rule 1118 (Cont.) (Amended November 4, 2005) 

2. Data Substitution Procedures 

For any time period for which the vent gas flow, the higher heating value or the 

total sulfur concentration, expressed as sulfur dioxide, are not measured, analyzed 

and recorded pursuant to the requirements of this rule, unless the owner or operator 

of a petroleum refinery, sulfur recovery plant or hydrogen production plant 

demonstrates using verifiable records of flare water seal level and/or other 

parameters as approved by the Executive Officer in the Flare Monitoring and 

Recording Plan or the Revised Flare Monitoring and Recording Plan that no flare 

event occurred during the period these parameters were not measured, analyzed or 

recorded, the operator shall substitute and report the following values: 

a) If the flow rate is not measured or recorded for any flare event, the totalized 

flow shall be calculated from the methodology in section 2(a)(i) below, 

unless the Executive Officer approves the method specified in Section 

2(a)(ii). 

i) The totalized flow shall be calculated from the product of the flare 

event duration and the estimated flow rate. The flow rate shall be 

calculated using the following equation for the period of time the flow 

meter was out of service: 

FR = Max. FR - 0.5(Max. FR - Avg. FR) 

Where: 

FR = Estimated Flow Rate (standard cubic feet per minute) 

Max FR = Maximum flow rate that was measured and recorded for 

that flare during the previous 20 quarters preceding the 

flare event. This maximum value is based on the 

average flow rate during an individual flare event, not 

an instantaneous maximum value. 

Avg FR = Average flow rate for all measured and recorded flow 

rates for all sampled flare events for that flare, during 

the previous 20 quarters preceding the subject flare 

event. 

The duration of a flare event during periods when the flow meter is out 

of service shall be determined using an alternate method approved by 

the Executive Officer in the Flare Monitoring and Recording Plan or 

Revised Flare Monitoring and Recording Plan. 

In the absence of an approved alternate method to determine the 

duration of the flare event during periods when the flow meter is out of 

service, the operator shall report the flare to be venting for the entire 

time the flow meter is out of service. 

ii) Alternate methods using recorded and verifiable operational parameters 

and/or process data, including reference to similar events that have 

previously occurred, approved by the Executive Officer to be 

representative of the volume of vent gas, may be used to determine the 

flow rate in lieu of the method specified above. 

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Rule 1118 (Cont.) (Amended November 4, 2005) 

b) If the higher heating value is not measured or recorded for any flare event 

pursuant to the requirements of this rule, the higher heating value shall be 

calculated from the methodology in section 2(b)(i) below, unless the 

Executive Officer approves the method specified in Section 2(b)(ii). 

i) The higher heating value shall be calculated using the following 

equation for the period of time this parameter was not measured or 

recorded: 

HHV = Max HHV – 0.5(Max HHV – Avg HHV) 

Where: 

HHV = Estimated higher heating value (Btu/scf) 

Max HHV = Maximum HHV measured and recorded for that flare 

during the previous 20 quarters preceding the flare 

event. 

Avg HHV = Average value of all HHV measured and recorded for 

that flare for all sampled flare events during the 

previous 20 quarters preceding the flare event. 

ii) Alternate methods using recorded and verifiable operational parameters 

and/ or process data, including reference to similar events that have 

previously occurred, approved by the Executive Officer to be 

representative of the HHV of the vent gas, may be used to determine 

the HHV in lieu of the method specified above. 

c) If the total sulfur concentration, expressed as sulfur dioxide, is not measured 

or recorded for any flare event pursuant to the requirements of this rule, it 

shall be calculated from the methodology in section 2(c)(i) below, unless the 

Executive Officer approves the method specified in Section 2(c)(ii). 

i) The total sulfur concentration expressed as sulfur dioxide shall be 

calculated using the following equation for the period of time this 

parameter was not measured or recorded: 

SFE = Max SFE – 0.5(Max SFE – Avg SFE) 

Where: 

SFE = Estimated total sulfur concentration, expressed as sulfur 

dioxide (ppmv) 

Max SFE = Maximum total sulfur concentration expressed as sulfur 

dioxide measured and recorded for that flare during the 

previous 20 quarters preceding the flare event. 

Avg SFE = Average value of all total sulfur concentrations 

measured and recorded for that flare for all sampled 

flare events during the previous 20 quarters preceding 

the flare event. 

ii) Alternate methods using recorded and verifiable operational parameters 

and/ or process data, including reference to similar events that have 

previously occurred, approved by the Executive Officer to be 

representative of the total sulfur concentration of the vent gas expressed 

1118 - 34 
Rule 1118 (Cont.) (Amended November 4, 2005) 

as sulfur dioxide, may be used to determine the total sulfur 

concentration in lieu of the method specified above. 

1118 - 35