RULE 2.34 STATIONARY GAS TURBINES

ADOPTED July 13, 1994

REVISED November 12, 2014

INDEX

100 GENERAL

101 PURPOSE

102 APPLICABILITY

103 SEVERABILITY

110 EXEMPTION – LABORATORY, FIREFIGHTING/FLOOD CONTROL, 

AND CHEMICAL PROCESSING UNITS

111 EXEMPTION – EMERGENCY STANDBY AND SMALL UNITS

200 DEFINITIONS

201 AUTOMATIC GENERATION CONTROL

202 CHEMICAL PROCESSING GAS TURBINE UNIT

203 COMBINED CYCLE

204 COMMISSIONING

205 COMPLIANCE LIMIT

206 CONTROL AREA SYSTEM OPERATOR

207 CONTROL SYSTEM OPERATING PARAMETERS

208 EMERGENCY STANDBY UNIT

209 MEASURED NOx EMISSIONS CONCENTRATION

210 NOx EMISSIONS (NOx)

211 POWER AUGMENTATION

212 PUBLIC SERVICE UNIT

213 RAMP RATE

214 RATING

215 SELECTIVE CATALYTIC REDUCTION (SCR)

216 SIMPLE CYCLE

217 SHORT-TERM EXCURSIONS

218 SHUT-DOWN PERIOD

219 START-UP PERIOD

220 STATIONARY GAS TURBINE

300 STANDARDS

301 EMISSION LIMITS

302 START-UP/SHUT-DOWN

303 CONTINUOUS MONTORING

304 SOURCE TESTING

400 ADMINISTRATIVE REQUIREMENTS

401 EXEMPTION APPLICABILITY

402 EMERGENCY STANDBY AND SMALL UNITS

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500 REPORTING AND RECORDKEEPING

501 REPORTING

502 RECORDKEEPING

600 TEST METHODS

601 Oxides of Nitrogen (NOx)

602 Oxygen (O2)

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100 GENERAL

101 PURPOSE: The purpose of this rule is to limit NOx emissions from stationary 

gas turbines.

102 APPLICABILITY: Except as provided in Sections 110 and 111, this rule shall 

apply to all stationary gas turbines, 0.3 megawatt (MW) and larger.

103 SEVERABILITY: If any provision, clause, sentence, paragraph, section or part 

of this rule for any reason is judged to be unconstitutional or invalid, such 

judgment shall not affect or invalidate the remainder of the rule.

110 EXEMPTION – LABORATORY, FIREFIGHTING/FLOOD CONTROL, 

AND CHEMICAL PROCESSING UNITS: The provisions of this rule with the 

exception of Section 401 shall not apply to the operation of stationary gas turbines 

used under the following conditions:

110.1 Laboratory units used in research and testing for the advancement 

of gas turbine technology.

110.2 Units operated exclusively for firefighting and/or flood control.

110.3 Chemical processing gas turbine units.

111 EXEMPTION – EMERGENCY STANDBY AND SMALL UNITS: The 

provisions of this rule with the exception of Sections 401, 402, and 502.2 shall not 

apply to the operation of stationary gas turbines used under the following 

conditions:

111.1 Emergency standby units demonstrated to operate less than 200 

hours per calendar year.

111.2 Units of less than 4 MW operating less than 877 hours per calendar 

year.

200 DEFINITIONS

201 AUTOMATIC GENERATION CONTROL: Computer linked remote 

command of the electrical power output of the generating plant by the control area 

system operation.

202 CHEMICAL PROCESSING GAS TURBINE UNIT: A stationary gas turbine 

that vents its exhaust gases into the operating stream of a chemical process.

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203 COMBINED CYCLE: Type of power plant in which electric generators are 

driven by both the expanding exhaust gases of fuel combustion in the gas turbine 

and by a steam turbine used to recover useful energy from the heat of a gas 

turbine exhaust.

204 COMMISSIONING: The period of initial equipment installation and tuning 

prior to the initial power deliveries to the electrical distribution grid.

205 COMPLIANCE LIMIT: Maximum allowable NOx emissions expressed in parts 

per million by volume (ppmv).

206 CONTROL AREA SYSTEM OPERATOR: The authority which is responsible 

for electrical power distribution in the local area containing the stationary gas 

turbine.

207 CONTROL SYSTEM OPERATING PARAMETERS: Operating parameters 

that the Air Pollution Control Officer deems necessary to analyze when 

determining compliance, such as ammonia and exhaust flow rates and exhaust gas 

temperature for SCR; or humidity, water injection rate, exhaust gas flow rate, and 

temperature for water injection.

208 EMERGENCY STANDBY UNIT: A stationary gas turbine that operates only as 

a mechanical or electrical power source for a facility when the primary power 

source has been rendered inoperable due to a failure beyond the reasonable 

control of the operator, except due to power interruption pursuant to a voluntary 

interruptible power supply agreement. Electricity generated by such a unit cannot 

be sold.

209 MEASURED NOx EMISSIONS CONCENTRATION: The concentration of 

NOx emissions corrected to the International Standards Organization (ISO) 

standard conditions:

NOx = (NOxobs)(Pref/Pobs)

0.5(288o

/Tamb)

1.53[e19(Hobs-0.00633)]

Where:

NOx = Emissions of NOx at 15 percent oxygen and ISO 

standard conditions on a dry basis, ppm.

NOxobs = Measured NOx emissions corrected to 15 percent 

oxygen on a dry basis, ppm.

Pref = Standard reference pressure, 14.696 psia.

Pobs = Measured site ambient absolute pressure, psia.

Hobs = Measured humidity of ambient air, pounds water 

per pound dry air.

e = Transcendental constant (2.718)

Tamb = Measured temperature of ambient air, degrees K. 

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or an alternate correlation that corrects to ISO standard conditions and is 

approved by the Air Pollution Control Officer.

210 NOx EMISSIONS (NOx): The sum of nitric oxides and nitrogen dioxide in the 

exhaust gas stream.

211 POWER AUGMENTATION: An increase in the gas turbine shaft output and/or 

the decrease in gas turbine fuel consumption by the addition of energy recovered 

from exhaust heat.

212 PUBLIC SERVICE UNIT: A gas turbine used to generate electricity for sale or 

for use in serving the public.

213 RAMP RATE: The rate of change in the quantity of electric power generated 

from the stationary gas turbine.

214 RATING: The continuous megawatt (MW) rating or mechanical equivalent by a 

manufacturer for gas turbine(s) without power augmentation.

215 SELECTIVE CATALYTIC REDUCTION (SCR): A post combustion control 

technology that utilizes ammonia injected into the exhaust gas stream where it 

reduces NOx to molecular nitrogen in the presence of a catalyst.

216 SIMPLE CYCLE: Type of power plant in which all electric generators are 

driven by the expanding exhaust gases of fuel combustion.

217 SHORT-TERM EXCURSIONS: Temporary departures from NOx emission 

limit compliant operation of a stationary gas turbine with a rated output greater 

than 100 MW, which is part of a combined cycle process, due to:

217.1 Turbine load changes in excess of the manufacturer’s recommended ramp 

rate required by the control area system operator while the power plant is 

operating under automatic generation control, or due to safety or 

equipment protection considerations.

217.2 Fuel pressure variations or automated modifications of the air/fuel mixture 

caused by safety or equipment protections systems.

217.3 Activation or deactivation of evaporative coolers, inlet air chillers, inlet air 

misting systems, duct burners, or power augmentation water or steam 

injection.

217.4 Other conditions identified by the operator and approved in writing by the 

Air Pollution Control Officer, the California Air Resources Board, and the 

U.S. Environmental Protection Agency.

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218 SHUT-DOWN PERIOD: The time necessary to cease operation of a gas turbine 

from operating under load conditions. This time shall not exceed one (1) hour.

219 START-UP PERIOD: The time necessary to bring operation of the gas turbine 

up to the designed rating. This time shall not exceed six (6) hours for combined 

cycle gas turbine power plants or two (2) hours for simple cycle gas turbine power 

plants.

220 STATIONARY GAS TURBINE: Any gas turbine system that is gas and/or 

liquid fueled with or without power augmentation. This unit is either attached to a 

foundation at a facility or is portable equipment operated at a specific facility for 

more than 90 days in any 12-month period. Two or more gas turbines powering 

one shaft shall be treated as one unit.

300 STANDARDS

301 EMISSIONS LIMITS: The owner or operator of any stationary gas turbine unit 

shall not operate such unit under conditions, excluding the start-up period, shutdown period, commissioning, or up to four (4) consecutive fifteen (15) minute 

periods during short-term excursions which result in the measured NOx emissions 

concentration exceeding the compliance limit listed below, averaged over 15 

minutes:

Unit Size

Megawatt Rating (MW)

Compliance Limit

NOx, ppm @ 15% O2

GasA LiquidB

0.3 to Less Than 2.9 MW and Units Greater 

Than or Equal to 4 MW That Operate Less 

Than 877 Hour/Year

42 65

2.9 to Less Than 10 MW 25 65

10.0 MW and Over 9 25 

A. GAS INCLUDES ONLY COMMERCIAL NATURAL AND LIQUIFIED PETROLEUM GASES.

B. LIQUID INCLUDES KEROSENE, JET, AND DISTILLATE. THE SULFUR CONTENT OF THE LIQUID SHALL BE 

LESS THAN 0.05%

301.1 The six (6) hour rolling average NOx concentration for a period including 

a short-term excursion shall not exceed the applicable compliance limit.

301.2 The total of all fifteen (15) minute periods during short-term excursions 

when NOx concentrations exceed the applicable compliance limit shall not 

exceed ten (10) hours in a year.

302 START-UP/SHUT-DOWN: The owner or operator of any stationary gas turbine 

shall operate such unit in accordance with good air pollution control practices at 

all times, including such periods containing start-up/shut-down events. Emissions 

shall not exceed an average value of 70 ppm @ 15% O2 during the start-up period

for turbines fired on gas fuels, or an average value of 226 ppm @ 15% O2 for 

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turbines fired on liquid fuels. SCR control shall be initiated once the temperature 

of the catalyst media achieves the minimum control operation temperature 

established by manufacturer recommendation or source test data, which shall be 

no higher than 550°F. Other emissions control devices shall operate continuously 

during start-up and shut-down events.

303 CONTINUOUS MONITORING: The owner or operator of any stationary gas 

turbine subject to Section 301 shall install, operate, and maintain in calibration 

equipment, as approved by the Air Pollution Control Officer, that continuously 

measures and records the following:

303.1 Control system operating parameters.

303.2 Elapsed time of operation.

303.3 For units with a rating of 10 MW or greater, the exhaust gas NOx 

concentrations corrected to ISO conditions at 15 percent oxygen on a dry 

basis. The NOx monitoring system shall meet EPA requirements as 

specified in 40 CFR Part 60, Appendix B or other systems that are 

acceptable to the EPA.

304 SOURCE TESTING:

304.1 The owner/operator of an affected unit subject to Section 301 shall have 

the stationary gas turbine source tested using the methods specified in 

sections 601, 602, and 603 at least once every 12 calendar months.

304.2 The owner/operator of an affected unit with a rating of 10 MW or greater

subject to the provisions of this rule shall perform a Relative Accuracy 

Test Audit (RATA) of the NOx continuous emission monitoring system at 

least once every four (4) successive Quality Assurance (QA) operating 

quarters (as defined by 40 CFR Part 72.2) or at least once every twenty 

four (24) calendar months, whichever is more stringent. The RATA shall 

be performed in accordance with 40 CFR Part 75, Appendix B (Quality 

Assurance and Quality Control Procedures).

400 ADMINISTATIVE REQUIREMENTS

401 EXEMPTION APPLICABILITY: The owner or operator of any existing 

stationary gas turbine shall submit to the Air Pollution Control Officer support 

documentation for any units exempt under the provisions of Sections 110 and 

111.

402 EMERGENCY STANDBY AND SMALL UNITS: Exempt units shall comply 

with the following:

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402.1 The owner or operator of any unit exempt under section 111 shall notify 

the Air Pollution Control Officer in writing within seven days if the hourper-year limit is exceeded. If the hour-per-year limit is exceeded, the 

exemption shall be permanently withdrawn. Within 30 days after the 

exceedance, the owner or operator shall submit an application for 

Authority to Construct that details a plan to meet the applicable limits 

specified in Section 301 of this rule within two years. Included in this 

application, the owner or operator shall submit a schedule of increments of 

progress for the installation of the required control equipment. This 

schedule shall be subject to the review and approval of the Air Pollution 

Control Officer.

402.2 A public service unit operating during a state of emergency, when such 

emergency is declared by proclamation of the Governor of the State of 

California and when the unit is located in the specific geographical 

location identified in the proclamation, shall be excluded from the hourper-year limit.

500 REPORTING AND RECORDKEEPING

501 REPORTING:

501.1 Submit to the Air Pollution Control Officer information demonstrating 

that the continuous monitoring system has data gathering and retrieval 

capability.

501.2 Submit to the Air Pollution Control Officer, prior to issuance of a Permit

to Operate, information correlating the control system operating 

parameters to the associated NOx output. This information may be used by 

the Air Pollution Control Officer to determine compliance when there is 

no continuous emission monitoring system for NOx available or when the 

continuous emission monitoring system is not operating properly.

501.3 Provide source test information annually regarding the exhaust gas NOx 

concentration at ISO conditions corrected to 15 percent oxygen on a dry 

basis.

502 RECORDKEEPING:

502.1 Maintain a gas turbine operating log that includes, on a daily basis, the 

actual Pacific Standard Time start-up and stop time, total hours of 

operation, type and quantity of fuel used (liquid/gas). This information 

shall be available for inspection at any time from the date of entry.

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502.2 For units exempt under Section 111 maintain a gas turbine operating log 

that includes, on a daily basis, the actual Pacific Standard Time start-up 

and stop time, total hours of operation, and cumulative hours of operation 

to date for the calendar year. This information shall be submitted to the 

Air Pollution Control Officer at the end of each calendar year in a manner 

and form approved by the Air Pollution Control Officer.

502.3 All records shall be available for inspection at any time for a period of five 

years.

600 TEST METHODS:

601 Oxides of Nitrogen (NOx): Oxides of Nitrogen (NOx) emissions shall be 

determined in accordance with EPA Method 7E or EPA Method 20.

602 Oxygen (O2): Oxygen (O2) concentrations shall be determined in 

accordance with ARB Method 100 or EPA Method 3A.

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