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 PIPELINE CHEMICAL PROCESSING UNITS

111 EXEMPTION – EMERGENCY STANDBY AND SMALL UNITS

200 DEFINITIONS

201 AUTOMATIC GENERATION CONTROL

201 BARCT

202202 CHEMICAL PROCESSING GAS TURBINE UNIT

203 COMBINED CYCLE

204 COMMISSIONING

203205 COMPLIANCE LIMIT

206 CONTROL AREA SYSTEM OPERATOR

204207 CONTROL SYSTEM OPERATING PARAMETERS

205208 EMERGENCY STANDBY UNIT

206 HHV

207 LHV

208209 MEASURED NOx EMISSIONS CONCENTRATION

209210 NOx EMISSIONS (NOx)

210 PIPELINE GAS TURBINES

211211 POWER AUGMENTATION

212212 PUBLIC SERVICE UNIT

213 RAMP RATE

213214 RATING

214215 SELECTIVE CATALYTIC REDUCTION (SCR)

216 SIMPLE CYCLE

217 SHORT-TERM EXCURSIONS

218 SHUT-DOWN PERIOD

219 START-UP PERIOD

215220 STATIONARY GAS TURBINE

216 THERMAL STABILIZATION PERIOD

300 STANDARDS

301 LIMITATIONSEMISSION LIMITS

302 START-UP/SHUT-DOWN

303 CONTINUOUS MONTORING

304 SOURCE TESTING

Yolo-Solano AQMD

Adopted July 13, 1994Revised November 12, 2014

(final draft 10/28/2014) Reg. II, Rule 2.34, Page 1
400 ADMINISTRATIVE REQUIREMENTS

401 COMPLIANCE SCHEDULE

402401 EMISSION CONTROL PLANEXEMPTION APPLICABILITY

403402 EXEMPT UNITS AND EMERGENCY STANDBY AND 

SMALL UNITS

500 MONITORINGREPORTING AND RECORDKEEPING

501 MONITORINGREPORTING

502 RECORDKEEPINGS

503 TEST METHODS

600 TEST METHODS

601 Oxides of Nitrogen (NOx)

602 Oxygen (O2)

Yolo-Solano AQMD

Adopted July 13, 1994Revised November 12, 2014

(final draft 10/28/2014) Reg. II, Rule 2.34, Page 2
100 GENERAL

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

gas turbines in conformance with BARCT determinations approved by the 

California Air Resources Board to meet the requirements of the California Clean 

Air Act.

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 PIPELINECHEMICAL PROCESSING UNITS: The provisions of this 

rule with the exception of Section 402.3401.3 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 Pipeline gas turbines provided that the owner/operator 

demonstrates to the satisfaction of the Air Pollution Control 

Officer that water or steam injection, selective catalytic reduction, 

or any other emission control technology is not technologically 

feasible, cost effective or creates adverse environmental impacts 

such as those associated with the use, transport, or disposal of 

supplies such as water and ammonia.

110.43 Chemical processing gas turbine units.

111 EXEMPTION – EMERGENCY STANDBY AND SMALL UNITS: The 

provisions of this rule with the exception of Sections 402.3401.3, 403402, and 

502.52 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.

Yolo-Solano AQMD

Adopted July 13, 1994Revised November 12, 2014

(final draft 10/28/2014) Reg. II, Rule 2.34, Page 3
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.

201 BARCT: “Best Available Retrofit Control Technology: as defined in Section 

40406 of the California Health and Safety Code as an “emission limitation that is 

based on the maximum degree of reduction achievable, taking into account 

environmental, energy, and economic impacts by each class or category of 

source”.

202202 CHEMICAL PROCESSING GAS TURBINE UNIT: A stationary gas 

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

process.

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.

203205 COMPLAINCE LIMIT: Maximum Aallowable 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.

204207 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; ofor humidity, water injection rate, exhaust gas 

flow rate, and temperature for water injection.

205208 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 

interruptaible power supply agreement. Electricity generated by such a unit 

cannot be sold.

206 HHV: The higher heating value of a fuel.

Yolo-Solano AQMD

Adopted July 13, 1994Revised November 12, 2014

(final draft 10/28/2014) Reg. II, Rule 2.34, Page 4
207 LHV: The lower heating value of the fuel.

208209 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. 

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

approved by the Air Pollution Control Officer.

209210 NOx EMISSIONS (NOx): The sum of nitric oxides and nitrogen dioxide 

in the exhaust gas stream.

210 PIPELINE GAS TURBINES: A stationary gas turbine used to transport gases or 

liquids in a pipeline.

211211 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.

212212 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.

213214 RATING: The continuous megawatt (MW) rating or mechanical 

equivalent by a manufacturer for gas turbine(s) without power augmentation.

214215 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.

Yolo-Solano AQMD

Adopted July 13, 1994Revised November 12, 2014

(final draft 10/28/2014) Reg. II, Rule 2.34, Page 5
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.

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.

215220 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.

216 THERMAL STABILIZATION PERIOD: The two hour start-up time necessary 

to bring the heat recovery steam generator to the proper temperature, not to 

exceed two (2) hours.

300 STANDARDS

301 LIMITATIONSEMISSIONS LIMITS: The owner or operator of any stationary 

gas turbine unit shall not operate such unit under loadconditions, excluding the 

thermal stabilizationstart-up period, shut-down period, commissioning, or up to 

Yolo-Solano AQMD

Adopted July 13, 1994Revised November 12, 2014

(final draft 10/28/2014) Reg. II, Rule 2.34, Page 6
four (4) consecutive fifteen (15) minute periods during short-term excursions

which results 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 OilLiquidB

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 x EFF/25 65

10.0 MW and Over 9 x EFF/25 25 x EFF/25

A. GAS INCLUDES ONLY COMMERCIAL NATURAL, DIGESTER, AND LANDFILL AND LIQUIFIED PETROLEUM

GASES.

B. OILLIQUID INCLUDES KEROSENE, JET, AND DISTILLATE. THE SULFUR CONTENT OF THE OILLIQUID 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 

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 

Yolo-Solano AQMD

Adopted July 13, 1994Revised November 12, 2014

(final draft 10/28/2014) Reg. II, Rule 2.34, Page 7
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).

Where: EFF(efficiency) is the higher of the following:

301.1 EFF = 3412 x 100%

 AHR

[where: AHR = Actual Heat Rate at HHV of Fuel (BTU/KW-HR)], which 

is the demonstrated percent efficiency of the gas turbine only as calculated 

without consideration of any downstream energy recovery from the actual 

heat rate, (BTU/KW-HR) or 1.34 (BTU/HP-HR); corrected to the HHV 

(higher heating value) of the fuel and ISO conditions, as measured at peak 

load for that facility, or

301.2 EFF = MRE x LHV

 HHV

[where: MRE = Manufacturer's Rated Efficiency with Air Pollution 

Equipment at LHV.], which is the manufacturer's continuous rated percent 

efficiency of the gas turbine with air pollution equipment after correction 

from LHV to HHV of the Fuel.

400 ADMINISTATIVE REQUIREMENTS

401 COMPLIANCE SCHEDULE: Owners or operators of all gas turbines subject to 

the provisions of this rule shall comply with the applicable provisions of Section

301 in accordance with the following schedule:

401.1 By July 13, 1996, submit to the Air Pollution Control Officer for approval 

an emission control plan of actions which will demonstrate compliance; and

Yolo-Solano AQMD

Adopted July 13, 1994Revised November 12, 2014

(final draft 10/28/2014) Reg. II, Rule 2.34, Page 8
401.2 Within 6 months after approval of the emission control plan specified in 

Section 402.1, submit an application for an Authority to Construct to the Air 

Pollution Control Officer; and

401.3 By July 13, 1998, demonstrate final compliance.

402401 EMISSION CONTROL PLANEXEMPTION APPLICABILITY: The 

owner or operator of any existing stationary gas turbine shall submit to the Air 

Pollution Control Officer for approval an Emissions Control Plan of all actions, 

including a schedule of increments of progress, which will be taken to meet or 

exceed requirements of the applicable emissions limitations in Section 301 and 

compliance schedule in Section 401.

402.1 The Emission Control Plan shall contain, as a minimum, a list that provides the 

following for each gas turbine subject to the provisions of this rule:

a. Permit or identification number;

b. Name of gas turbine manufacturer;

c. Model designation;

d. Rated shaft power output (MW);

e. Type of liquid fuel and/or type of gaseous fuel;

f. Fuel consumption (cubic feet of gas or gallons of liquid) for the previous one-year 

period;

g. Hours of operation in the previous one-year period;

h. Heat rate (BTU/KW-HR), corrected to the HHV for each type of fuel (liquid/gas), 

and

i. HHV for each fuel.

402.2 A listing of all gas turbines required to be controlled, identifying the type of 

emission control to be applied to each gas turbine along with documentation 

showing existing emissions of oxides of nitrogen.

402.3 Support documentation for any units exempt under the provisions of 

Sections 110 and 111.

403402 EXEMPT UNITS AND EMERGENCY STANDBY AND SMALL 

UNITS: Exempt units and emergency standby units shall comply with the 

following:

403.1402.1 The owner or operator of any unit listed belowexempt under 

section 111 shall notify the Air Pollution Control Officer in writing within 

seven days if the hour-per-year limit is exceeded. 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 hour-per-year limit. If the hourper-year limit is exceeded, the exemption shall be permanently withdrawn. 

Yolo-Solano AQMD

Adopted July 13, 1994Revised November 12, 2014

(final draft 10/28/2014) Reg. II, Rule 2.34, Page 9
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 an 

emission control plan that includes 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.

a. Any unit smaller than 4 MW or emergency standby unit 

exempt under Sections 110 and 111.

b. Any unit equal to or greater than 4 MW.

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 MONITORINGREPORTING AND RECORDKEEPING

501 MONITORING: The owner or operator of any stationary gas turbine subject to 

the provisions of this rule shall perform the following actions:

501.1 Install, operate and maintain in calibration equipment, as approved by the 

Air Pollution Control Officer, that continuously measures and records the 

following:

a. Control system operating parameters;

b. Elapsed time of operation; and

c. For units of 10 MW or greater that operated more than 

4000 hours per year over the last three years prior to July 

13, 1994, 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, App. B, Spec.2 or other 

systems that are acceptable to the EPA.

5021 RECORDSREPORTING:

502.1 All records shall be available for inspection at any time for a period of two

years.

5021.21 Submit to the Air Pollution Control Officer information 

demonstrating that the continuous monitoring system has data gathering 

and retrieval capability.

5021.32 Submit to the Air Pollution Control Officer, prior to issuance of a 

Permit to Operate, information correlating the control system operating 

Yolo-Solano AQMD

Adopted July 13, 1994Revised November 12, 2014

(final draft 10/28/2014) Reg. II, Rule 2.34, Page 10
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.

5021.43 Provide source test information annually regarding the exhaust gas 

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

dry basis, and the demonstrated percent efficiency (EFF) of the turbine 

unit.

502 RECORDKEEPING:

502.51 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.

502.62 For units exempt under Section 111 Mmaintain a gas turbine operating log 

for units exempt under Section 111 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 available for inspection at any time for two years 

from the date of entry and 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.

503600 TEST METHODS:

503.1601 Oxides of Nitrogen (NOx): Oxides of Nitrogen (NOx) emissions 

shall be determined in accordance with EPA Method 7E or EPA Method 

20.

503.2602 Oxygen (O2): Oxygen (O2) concentrations shall be determined in 

accordance with ARB Method 100 or EPA Method 3A.

503.3 HHV and LHV: HHV and LHV shall be determined in accordance with 

ASTM D-240-87, Standard Test Method for Heat of Combustion of 

Liquid Hydrocarbon Fuels by Bomb Calorimeter, or D-2382-88, Standard 

Test Method for Heat of Combustion of Hydrocarbon Fuels by Bomb 

Calorimeter (High-precision Method), for distillate fuels, and ASTM D3588-91,Standard Practice for Calculating Heat Value, Compressibility 

Factor, and Relative Density (Specific Gravity) of Gaseous Fuels, ASTM 

D-1826-88, Standard Test Method for Calorific (Heating) Value of Gases 

Yolo-Solano AQMD

Adopted July 13, 1994Revised November 12, 2014

(final draft 10/28/2014) Reg. II, Rule 2.34, Page 11
in Natural Gas Range by Continuous Recording Calorimeter, or ASTM D1945-81, Standard Method for Analysis of Natural Gas by Gas 

Chromatography, for gaseous fuels.

Yolo-Solano AQMD

Adopted July 13, 1994Revised November 12, 2014

(final draft 10/28/2014) Reg. II, Rule 2.34, Page 12