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RULE 4306 BOILERS, STEAM GENERATORS, AND PROCESS HEATERS – PHASE 3 

(Adopted September 18, 2003; Amended March 17, 2005; Amended October 16, 

2008) 

1.0 Purpose 

 The purpose of this rule is to limit emissions of oxides of nitrogen (NOx) and carbon 

monoxide (CO) from boilers, steam generators, and process heaters. 

2.0 Applicability 

 This rule applies to any gaseous fuel or liquid fuel fired boiler, steam generator, or process 

heater with a total rated heat input greater than 5 million Btu per hour. 

3.0 Definitions 

3.1 Annual Capacity Factor: the ratio of the amount of fuel burned by the unit in a 

calendar year to the amount of fuel that the unit could have burned if it had operated 

at its maximum rated capacity for 8,760 hours during the calendar year. 

3.2 Annual Heat Input: the actual, total heat input of fuels burned by a unit in a 

calendar year, as determined from the higher heating value and cumulative annual 

usage of each fuel. 

3.3 Boiler or Steam Generator: any external combustion equipment, except oilfield 

steam generators, fired with any fuel used to produce hot water or steam. 

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

one pound of water from 59°F to 60°F at one atmosphere. 

3.5 Dryer: any unit in which material is dried in direct contact with the products of 

combustion. 

3.6 Gaseous Fuel: any fuel which is a gas at standard conditions. 

3.7 Gas Liquids Processing Facility: a facility that is engaged in the catalytic processing 

of gas liquids to produce finished products. 

3.8 Heat Input: the heat (hhv basis) released due to fuel combustion in a unit, not 

including the sensible heat of incoming combustion air and fuel. 

3.9 Higher Heating Value (hhv): the total heat liberated per mass of fuel burned (Btu 

per pound), when fuel and dry air at standard conditions undergo complete 

combustion and all resulting products are brought to their standard states at standard 

conditions. 
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3.10 Liquid Fuel: any fuel which is a liquid at standard conditions. 

3.11 Load-following Unit: for the purposes of this rule, a load-following unit is defined 

as a unit with normal operational load fluctuations and requirements which exceed 

the operational response range of an Ultra-Low NOx burner system(s) operating at 9 

ppmv NOx. The operator shall designated load-following units on the Permit to 

Operate. 

3.12 NOx Emissions: the sum of oxides of nitrogen expressed as NO2

 in the flue gas. 

3.13 Oilfield Steam Generator: an external combustion equipment which converts water 

to dry steam or to a mixture of water vapor and steam, with an absolute pressure of 

more than 30 psia, and which is used exclusively in thermally enhanced crude oil 

production. 

3.14 Parts Per Million by Volume (ppmv): the ratio of the number of gas molecules of a 

given species, or group of species, to the number of millions of total gas molecules. 

3.15 Process Heater: any combustion equipment fired with liquid and/or gaseous fuel 

and which transfers heat from combustion gases to water or process streams. This 

definition excludes: kilns or ovens used for drying, baking, cooking, calcining, or 

vitrifying; and unfired waste heat recovery heaters used to recover sensible heat 

from the exhaust of combustion equipment. 

3.16 Public Utilities Commission (PUC) Quality Natural Gas: any gaseous fuel, gascontaining fuel where the sulfur content is no more than one-fourth (0.25) grain of 

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

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

natural gas also means high methane gas (at least 80% methane by volume) as 

specified in PUC General order 58-A. 

3.17 PUC Quality Natural Gas Curtailment: means a shortage in the supply of Public 

Utility Commission (PUC) quality natural gas, due solely to supply limitations or 

restrictions in distribution pipelines by the utility supplying the gas, and not due to 

the cost of natural gas. 

3.18 Qualified Technician: a stationary source employee or any personnel contracted by 

a stationary source operator who has a documented training and a demonstrated 

experience performing tune-ups on a unit to the satisfaction of the APCO. The 

documentation of tune-up training and experience shall be made available to the 

APCO upon request. 

3.19 Rated Heat Input (million Btu per hour): the heat input capacity specified on the 

nameplate of the unit. If the unit has been physically modified such that its 

maximum heat input differs from what is specified on the nameplate, the modified 
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maximum heat input shall be considered as the rated heat input and made 

enforceable by Permit to Operate. 

3.20 Refinery Unit: a unit that is permanently installed and operated at a petroleum 

refinery or a gas liquids processing facility. 

3.21 Re-ignition: the relighting of a unit after an unscheduled and unavoidable 

interruption or shut off of the fuel flow or electrical power, for a period of less 

than 30 minutes, due to reasons outside the control of the operator. 

3.22 Shutdown: the period of time during which a unit is taken from an operational to 

a non-operational status by allowing it to cool down from its operating 

temperature to ambient temperature as the fuel supply to the unit is completely 

turned off. 

3.23 Solid Fuel: any fuel which is a solid at standard conditions. 

3.24 Standard Conditions: standard conditions as defined in Rule 1020 (Definitions). 

3.25 Start-up: the period of time during which a unit is brought from a shutdown status 

to its operating temperature and pressure, including the time required by the unit’s 

emission control system to reach full operation. 

3.26 Unit: any boiler, steam generator, oilfield steam generator, or process heater as 

defined in this rule. 

4.0 Exemptions 

 4.1 This rule shall not apply to: 

 4.1.1 Solid fuel fired units. 

 4.1.2 Dryers and glass melting furnaces. 

 4.1.3 Kilns and smelters where the products of combustion come into direct 

contact with the material to be heated. 

 

 4.1.4 Unfired or fired waste heat recovery boilers that are used to recover or 

augment heat from the exhaust of combustion turbines or internal 

combustion engines. 

 

 4.2 The requirements of Sections 5.1.1 and 5.1.2 shall not apply to a unit when burning 

any fuel other than PUC quality natural gas during PUC quality natural gas 

curtailment provided all of the following conditions are met: 
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 4.2.1 Fuels other than PUC quality natural gas are burned no more than 168 

cumulative hours in a calendar year plus 48 hours per calendar year for 

equipment testing, as limited by Permit to Operate.

4.2.2 NOx emission shall not exceed 150 ppmv or 0.215 lb/MMBtu. 

Demonstration of compliance with this limit shall be made by either source 

testing, continuous emission monitoring system (CEMS), an APCO 

approved Alternate Monitoring System, or an APCO approved portable 

NOx analyzer. 

5.0 Requirements 

All ppmv emission limits specified in this section are referenced at dry stack gas conditions 

and 3.00 percent by volume stack gas oxygen. Emission concentrations shall be corrected 

to 3.00 percent oxygen in accordance with Section 8.1. 

5.1 NOx and CO Emission Limits 

 

 5.1.1 Except for units subject to Sections 5.2, NOx and carbon monoxide (CO) 

emissions shall not exceed the limits specified in Table 1 on and after the 

dates specified in Tables 2 and 3. 

Table 1 NOx and CO Limits 

Operated on Gaseous Fuel Operated on Liquid Fuel 

NOx Limit 

Category 

Standard Option Enhanced Option

CO 

Limit 

(ppmv)

NOx Limit CO Limit 

(ppmv) 

A. Units with a rated heat 

input equal to or less than 

20.0 MMBtu/hour, except 

for Categories C, D, E, F, 

G, H, and I units 

15 ppmv or 

0.018 lb/MMBtu 

9 ppmv or 

0.011 lb/MMBtu 

400 40 ppmv or 

0.052 

lb/MMBtu 

400

B. Units with a rated heat 

input greater than 20.0 

MMBtu/hour, except for 

Categories C, D, E, F, G, 

H, and I units 

9 ppmv or 

0.011 lb/MMBtu 

6 ppmv or 

0.007 lb/MMBtu 

400 40 ppmv or 

0.052 

lb/MMBtu 

400

C. Oilfield Steam Generators 15 ppmv or 

0.018 lb/MMBtu No option 400 

40 ppmv or 

0.052 

lb/MMBtu 

400 

Table 1 NOx and CO Limits (continued) 
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Operated on Gaseous Fuel Operated on Liquid Fuel 

NOx Limit 

Category 

Standard Option Enhanced 

Option 

CO 

Limit 

(ppmv)

NOx Limit CO Limit 

(ppmv) 

D. Refinery units with a rated 

heat input greater than 5 

MMBtu/hr up to 65 

MMBtu/hr 

30 ppmv or 0.036 

lb/MMBtu 

No option 400 40 ppmv or 

0.052 

lb/MMBtu 

400 

E. Refinery units with a rated 

heat input greater than 65 

MMBtu/hr up to 110 

MMBtu/hr 

25 ppmv or 

0.031 lb/MMBtu 

No option 400 40 ppmv or 

0.052 

lb/MMBtu 

400 

F. Refinery units with a rated 

heat input greater than 110 

MMBtu/hr 

5 ppmv or 

0.0062 

lb/MMBtu 

No option 400 40 ppmv or 

0.052 

lb/MMBtu 

400 

G. Load-following units 15 ppmv or 0.018 

lb/MMBtu

9 ppmv or 0.011 

lb/MMbtu

400 40 ppmv or 

0.052 

lb/MMBtu 

400 

H. Units limited by a Permit 

to Operate to an annual 

heat input of 9 billion 

Btu/year to 30 billion 

Btu/year 

30 ppmv or 0.036 

lb/MMBtu No option 400 

40 ppmv or 

0.052 

lb/MMBtu 

400 

I. Units in which the rated 

heat input of each burner is 

less than or equal to 5 

MMBtu/hr but the total 

rated heat input of all the 

burners in a unit is greater 

than 5 MMBtu/hr, as 

specified in the Permit to 

Operate, and in which the 

products of combustion do 

not come in contact with 

the products of combustion 

of any other burner. 

30 ppmv or 0.036 

lb/MMBtu No option 400 40 ppmv or 0.052 

lb/MMBtu 

400 

5.1.2 When a unit is operated on combinations of gaseous fuel and liquid fuel, the 

NOx limit shall be the heat input weighted average of the applicable limits 

specified in Sections 5.1.1, as calculated by the following equation: 

G L

(NOx limitfor gaseousfuel x G) (NOx limitforliquid fuel x )L Weighted AverageLimit

+

+

=
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 Where: G = annual heat input from gaseous fuel 

 L = annual heat input from liquid fuel 

 5.2 For each unit that is limited to less than 9 billion Btu per calendar year heat input 

pursuant to a Permit to Operate, the operator shall comply with the requirement of 

Section 7.4 and one of the following: 

 5.2.1 tune the unit at least twice per calendar year, (from four to eight months 

apart) by a qualified technician in accordance with the procedure described 

in Rule 4304 (Equipment Tuning Procedure for Boilers, Steam Generators, 

and Process Heaters). If the unit does not operate throughout a continuous 

six-month period within a calendar year, only one tune-up is required for 

that calendar year. No tune-up is required for any unit that is not operated 

during that calendar year; this unit may be test fired to verify availability of 

the unit for its intended use, but once the test firing is completed the unit 

shall be shutdown; or 

 

 5.2.2 operate the unit in a manner that maintains exhaust oxygen concentrations at 

less than or equal to 3.00 percent by volume on a dry basis; or 

 5.2.3 operate the unit in compliance with the applicable emission limits of 

Sections 5.1.1 or 5.1.2. 

5.3 On and after the full compliance schedule specified in Section 7.1, the applicable 

emission limits of Sections 5.1, 5.2.2 and 5.2.3 shall not apply during start-up or 

shutdown provided an operator complies with the requirements specified below. 

5.3.1 The duration of each start-up or each shutdown shall not exceed two 

hours, except as provided in Section 5.3.3. 

5.3.2 The emission control system shall be in operation and emissions shall be 

minimized insofar as technologically feasible during start-up or shutdown. 

5.3.3 Notwithstanding the requirement of Section 5.3.1, an operator may submit 

an application for a Permit to Operate condition to allow more than two 

hours for each start-up or each shutdown provided the operator meets all 

of the conditions in specified in Sections 5.3.3.1 through 5.3.3.3. 

5.3.3.1 The maximum allowable duration of start-up or shutdown will 

be determined by the APCO. The allowable duration of start-up 

shall not exceed twelve hours and the allowable duration of 

shutdown shall not exceed nine hours. 

5.3.3.2 The APCO will only approve start-up or shutdown duration longer 

than two hours when the application meets the following 

conditions: 
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 5.3.3.2.1 clearly identifies the control technologies or 

strategies to be utilized; and 

 

 5.3.3.2.2 describes what physical conditions prevail during 

start-up or shutdown periods that prevent the 

controls from being effective; and 

 5.3.3.2.3 provides a reasonably precise estimate as to when 

the physical conditions will have reached a state 

that allows for the effective control of emissions. 

 5.3.3.3 The operator shall submit to the APCO any information deemed 

necessary by the APCO to determine the appropriate length of 

start-up or shutdown. The information shall include, but is not 

limited to the following: 

 5.3.3.3.1 a detailed list of activities to be performed during 

start-up or shutdown and a reasonable explanation 

for the length of time needed to complete each 

activity; and 

 5.3.3.3.2 a description of the material process flow rates and 

system operating parameters, etc., the operator plans 

to evaluate during the process optimization; and an

explanation of how the activities and process flow 

affect the operation of the emissions control 

equipment; and 

 5.3.3.3.3 basis for the requested additional duration of startup or shutdown. 

 5.3.4 Permit to Operate (PTO) modifications solely to include start-up or 

shutdown conditions may be exempt from Best Available Control 

Technology (BACT) and emission offset requirements if the PTO 

modifications meet the requirements of Rule 2201 (New or Modified 

Stationary Source Review Rule) Section 4.2 (BACT Exemptions) and 

Rule 2201 Section 4.6 (Offset Exemptions). 

 5.4 Monitoring Provisions 

 

 5.4.1 The operator of any unit which simultaneously fires gaseous and liquid 

fuels, and is subject to the requirements of Section 5.1, shall install and 

maintain an operational non-resettable, totalizing mass or volumetric flow 
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meter in each fuel line to each unit. Volumetric flow measurements shall be 

periodically compensated for temperature and pressure. 

 5.4.2 The operator of any unit subject to the applicable emission limits in Sections 

5.1 shall install and maintain an operational APCO approved Continuous 

Emissions Monitoring System (CEMS) for NOx, CO, and oxygen, or 

implement an APCO-approved Alternate Monitoring System. An APCO 

approved CEMS shall comply with the requirements of 40 Code of Federal 

Regulations (CFR) Part 51, 40 CFR Parts 60.7 and 60.13 (except subsection 

h), 40 CFR Part 60 Appendix B (Performance Specifications) and 40 CFR 

Part 60 Appendix F (Quality Assurance Procedures, and applicable 

provisions of Rule 1080 (Stack Monitoring). An APCO approved Alternate 

Monitoring System shall monitor one or more of the following: 

 5.4.2.1 periodic NOx and CO exhaust emission concentrations, 

 5.4.2.2 periodic exhaust oxygen concentration, 

 5.4.2.3 flow rate of reducing agent added to exhaust, 

 5.4.2.4 catalyst inlet and exhaust temperature, 

 5.4.2.5 catalyst inlet and exhaust oxygen concentration, 

 5.4.2.6 periodic flue gas recirculation rate, 

 5.4.2.7 other operational characteristics. 

 

 5.4.3 For units subject to the requirements of Section 5.2.1 or 5.2.2, the operator 

shall monitor, at least on a monthly basis, the operational characteristics 

recommended by the manufacturer and approved by the APCO. 

5.4.4 The operator of any Category H unit listed in Section 5.1.1 Table 1 and any 

unit subject to Section 5.2.1 or 5.2.2 shall install and maintain an operational 

non-resettable, totalizing mass or volumetric flow meter in each fuel line to 

each unit. Volumetric flow measurements shall be periodically compensated 

for temperature and pressure. A master meter, which measures fuel to all 

units in a group of similar units, may satisfy these requirements if approved 

by the APCO in writing. The cumulative annual fuel usage may be verified 

from utility service meters, purchase or tank fill records, or other acceptable 

methods, as approved by the APCO. 

5.4.5 The APCO shall not approve an alternative monitoring system unless it is 

documented that continued operation within ranges of specified emissionsrelated performance indicators or operational characteristics provides a 

reasonable assurance of compliance with applicable emission limits. The 

operator shall source test over the proposed range of surrogate operating 

parameters to demonstrate compliance with the applicable emission 

standards. 

 5.5 Compliance Determination 

 
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 5.5.1 The operator of any unit shall have the option of complying with either the 

applicable heat input (lb/MMBtu) emission limits or the concentration 

(ppmv) emission limits specified in Section 5.1. The emission limits 

selected to demonstrate compliance shall be specified in the source test 

proposal pursuant to Rule 1081 (Source Sampling). 

5.5.2 All emissions measurements shall be made with the unit operating either at 

conditions representative of normal operations or conditions specified in the 

Permit to Operate. Unless otherwise specified in the Permit to Operate no 

determination of compliance shall be established within two hours after a 

continuous period in which fuel flow to the unit is shut off for 30 minutes or 

longer, or within 30 minutes after a re-ignition as defined in Section 3.0. 

 

 5.5.3 All Continuous Emissions Monitoring System (CEMS) emissions 

measurements shall be averaged over a period of 15 consecutive minutes to 

demonstrate compliance with the applicable emission limits of this rule. 

Any 15-consecutive-minute block average CEMS measurement exceeding 

the applicable emission limits of this rule shall constitute a violation of this 

rule. 

5.5.4 For emissions monitoring pursuant to Sections 5.4.2, 5.4.2.1, and 6.3.1 using 

a portable NOx analyzer as part of an APCO approved Alternate Emissions 

Monitoring System, emission readings shall be averaged over a 15 

consecutive-minute period by either taking a cumulative 15-consecutiveminute sample reading or by taking at least five (5) readings evenly spaced 

out over the 15-consecutive-minute period. 

 

5.5.5 For emissions source testing performed pursuant to Section 6.3.1 for the 

purpose of determining compliance with an applicable standard or numerical 

limitation of this rule, the arithmetic average of three (3) 30-consecutiveminute test runs shall apply. If two (2) of three (3) runs are above an 

applicable limit the test cannot be used to demonstrate compliance with an 

applicable limit. 

6.0 Administrative Requirements 

 6.1 Recordkeeping 

 The records required by Sections 6.1.1 through 6.1.4 shall be maintained for five 

calendar years and shall be made available to the APCO upon request. Failure to 

maintain records or information contained in the records that demonstrate 

noncompliance with the applicable requirements of this rule shall constitute a 

violation of this rule. 
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 6.1.1 The operator of any unit operated under the exemption of Section 4.2 shall 

monitor and record for each unit the cumulative annual hours of operation 

on each fuel other than natural gas during periods of natural gas curtailment 

and equipment testing. The NOx emission concentration (in ppmv or 

lb/MMBtu) for each unit that is operated during periods of natural gas 

curtailment shall be recorded. Failure to maintain records required by 

Section 6.1.1 or information contained in the records that demonstrates 

noncompliance with the conditions for exemption under Section 4.2 will 

result in loss of exemption status. On and after the applicable compliance 

schedule specified in Section 7.0, any unit losing an exemption status shall 

be brought into full compliance with this rule as specified in Section 7.3. 

 6.1.2 The operator of any Category H unit listed in Section 5.1.1 Table 1 and any 

unit that is subject to the requirements of Section 5.2 shall record the amount 

of fuel use at least on a monthly basis for each unit, or for a group of units as 

specified in Section 5.4.4. On and after the applicable compliance schedule 

specified in Section 7.0, in the event that such unit exceeds the applicable 

annual heat input limit specified in Sections 5.1.1 Table 1 Category H and 

Section 5.2, the unit shall be brought into full compliance with this rule as 

specified in Section 7.4. 

 

 6.1.3 The operator of any unit subject to Section 5.2.1 or Section 6.3.1 shall 

maintain records to verify that the required tune-up and the required 

monitoring of the operational characteristics of the unit have been 

performed. 

 

 6.1.4 The operator performing start-up or shutdown of a unit shall keep records of 

the duration of start-up or shutdown. 

 6.2 Test Methods 

The following test methods shall be used unless otherwise approved by the APCO 

and EPA. 

 

 6.2.1 Fuel hhv shall be certified by third party fuel supplier or determined by: 

 6.2.1.1 ASTM D 240-87 or D 2382-88 for liquid hydrocarbon fuels; 

 6.2.1.2 ASTM D 1826-88 or D 1945-81 in conjunction with ASTM D 

3588-89 for gaseous fuels. 

 6.2.2 Oxides of nitrogen (ppmv) - EPA Method 7E, or ARB Method 100. 

 6.2.3 Carbon monoxide (ppmv) - EPA Method 10, or ARB Method 100. 
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 6.2.4 Stack gas oxygen - EPA Method 3 or 3A, or ARB Method 100. 

 6.2.5 NOx Emission Rate (Heat Input Basis) - EPA Method 19. 

 6.2.6 Stack gas velocities - EPA Method 2. 

 6.2.7 Stack gas moisture content - EPA Method 4. 

 

6.3 Compliance Testing 

 6.3.1 Each unit subject to the requirements in Sections 5.1 or 5.2.3 shall be source 

tested to determine compliance with the applicable emission limits at least 

once every 12 months, (no more than 30 days before or after the required 

annual source test date). Units that demonstrate compliance on two 

consecutive 12-month source tests may defer the following 12-month source 

test for up to 36 months (no more than 30 days before or after the required 

36-month source test date). During the 36-month source testing interval, 

the operator shall tune the unit in accordance with the provisions of Section 

5.2.1, and shall monitor, on a monthly basis, the unit’s operational 

characteristics recommended by the manufacturer to ensure compliance with 

the applicable emission limits specified in Sections 5.1 or 5.2.3. Tune-ups 

required by Sections 5.2.1 and 6.3.1 do not need to be performed for units 

that operate and maintain an APCO approved CEMS or an APCO approved 

Alternate Monitoring System where the applicable emission limits are 

periodically monitored. If the result of the 36-month source test 

demonstrates that the unit does not meet the applicable emission limits 

specified in Sections 5.1 or 5.2.3, the source testing frequency shall revert to 

at least once every 12 months. Failure to comply with the requirements 

Section 6.3.1, or any source test results that exceed the applicable emission 

limits in Sections 5.1 or 5.2.3 shall constitute a violation of this rule. 

6.3.2 In lieu of compliance with Section 6.3.1, compliance with the applicable 

emission limits in Sections 5.1 or 5.2.3 shall be demonstrated by submittal 

of annual emissions test results to the District from a unit or units that 

represents a group of units, provided: 

 

 6.3.2.1 All units in the group are initially source tested. The emissions 

from all test runs from units within the group are less than 90% 

of the permitted value, and the emissions do not vary greater than 

25% from the average of all test runs; and 

 6.3.2.2 All units in a group are similar in terms of rated heat input, make 

and series, operational conditions, fuel used, and control method. 

No unit with a rated heat input greater than 100 MMBtu shall be 

considered as part of the group; and 

 6.3.2.3 The group is owned by a single owner and is located at a single 

stationary source; and 
SJVUAPCD 4306 - 12 10/16/08

 6.3.2.4 Selection of the representative unit(s) is approved by the APCO 

prior to testing; and 

 

 6.3.2.5 The number of representative units source tested shall be at least 

30% of the total number of units in the group. The

representative tests shall rotate each year so that within three 

years all units in the group have been tested at least once. 

 

6.3.2.6 All units in the group shall have received the similar 

maintenance and tune-up procedures as the representative unit(s) 

as listed in the Permit to Operate. The operator shall submit to 

the APCO the specific maintenance procedures to be performed 

on each unit that will be included in the group for representative 

testing. Such maintenance procedures shall be specified in the 

Permit to Operate for units that are included in the group for 

representative testing. Any maintenance work on a unit which 

has no effect on emissions standards and which is not specified 

in the maintenance procedures shall be submitted to the APCO 

for approval before such unit can be included as part of the group 

for representative testing. Any unit that necessitates any 

maintenance work which has an effect on emission standards and 

is beyond the maintenance procedures identified in the Permit to 

Operate, shall not be included as part of the group for 

representative testing. The unit shall be source tested in 

accordance with the provisions of Section 6.3.1; and 

 6.3.2.7 Should any of the representative units exceed the required 

emission limits, each of the units in the group shall demonstrate 

compliance by emissions testing. Failure to complete emissions 

testing within 90 days of the failed test shall result in the untested 

units being in violation of this rule. After compliance with the 

requirements of Section 6.3.2.7 has been demonstrated, 

subsequent source testing shall be performed pursuant to 

Sections 6.3.1 or 6.3.2. 

 6.4 Emission Control Plan (ECP) 

 6.4.1 The operator of any unit shall submit to the APCO for approval an 

Emissions Control Plan according to the compliance schedule in Section 7.0. 

 For each unit, the plan shall contain the following: 

 

 6.4.1.1 Permit to Operate number, 

 6.4.1.2 Fuel type and hhv, 

 6.4.1.3 Annual fuel consumption (Btu/yr), 
SJVUAPCD 4306 - 13 10/16/08

6.4.1.4 Current emission level, including method used to determine 

 emission level, 

6.4.1.5 NOx limit to be satisfied, either Standard Option or Enhanced 

 Option, and 

 6.4.1.6 Plan of actions, including a schedule of increments of progress, 

which will be taken to satisfy the requirements of Section 5.0 and 

the compliance schedule in Section 7.0. 

6.4.2 The operator shall submit to the APCO for approval, as part of the ECP, a 

list of units which are to be designated as load-following units. The APCO 

shall only designate, as load-following, units for which the following 

information has been provided to demonstrate that the units qualify as loadfollowing: 

6.4.2.1 Technical data such as steam demand charts or other information 

to demonstrate the normal operational load fluctuations and 

requirements of the unit, 

6.4.2.2 Technical data about the operational response range of an UltraLow NOx burner system(s) operating at 9 ppmv NOx, and 

6.4.2.3 Technical data demonstrating that the unit(s) are designed and 

 operated to optimize the use of base-loaded units in conjunction 

with the load-following unit(s). 

 

7.0 Compliance Schedule 

7.1 An operator with multiple units at a stationary source shall comply with this rule in 

accordance with the schedule specified in Table 2. A stationary source with only 

one unit shall comply with the schedule specified in Table 2 Group 1 for standard 

option or Table 3 Group 1 for enhanced option. 

 TABLE 2 – Standard Option Compliance Schedule 

Units to be in Compliance at a 

Stationary Source 

Emission Control 

Plan 

Authority to 

Construct 

Full Compliance

Group 1: 

25% or more of the total number of 

units subject to this rule on June 1, 

2005, excluding Group 4 

June 1, 2004 June 1, 2004 June 1, 2005 

Group 2: 

62.5% or more of the total number of 

units subject to this rule on June 1, 

2006, excluding Group 4 

June 1, 2004 January 2, 2005 June 1, 2006 
SJVUAPCD 4306 - 14 10/16/08

Group 3: 

100% of the total number of units 

subject to this rule on June 1, 2007 

June 1, 2004 January 2, 2006 June 1, 2007 

Group 4: 

A. Load-following units 

B. Units limited by Permit to 

 Operate to an annual capacity 

 factor of 10% or less as of 

 June 1, 2005 

C. Category I units at any 

 stationary source that has no 

 more than two units subject 

 to this rule. 

June 1, 2004 January 2, 2006 June 1, 2007 

Units are considered to be subject to this rule if the rule is applicable to the units pursuant to 

Section 2.0 and the units are not exempt pursuant to Section 4.1. 

TABLE 3 – Enhanced Option Compliance Schedule 

Units to be in Compliance at a 

Stationary Source 

Emission Control 

Plan 

Authority to 

Construct 

Full Compliance 

Group 1: 

25% or more of the total number of 

units subject to this rule on June 1, 

2005, excluding Group 4 

December 1, 2005 December 1, 2005 December 1, 2006 

Group 2: 

62.5% or more of the total number 

of units subject to this rule on June 

1, 2006, excluding Group 4 

December 1, 2005 July 1, 2006 December 1, 2007 

Group 3: 

100% of the total number of units 

subject to this rule on June 1, 2007 

December 1, 2005 July 1, 2007 December 1, 2008 

TABLE 3 – Enhanced Option Compliance Schedule (Continued) 

Units to be in Compliance at a 

Stationary Source 

Emission Control 

Plan 

Authority to 

Construct Full Compliance

Group 4: 

A. Load-following units December 1, 2005 July 1, 2007 December 1, 

2008 

Units are considered to be subject to this rule if the rule is applicable to the units pursuant to 

Section 2.0 and the units are not exempt pursuant to Section 4.1. 

 7.2 As shown in Table 2 and Table 3, the column labeled: 

 7.2.1 "Emission Control Plan" identifies the date by which the operator shall 

submit an Emission Control Plan pursuant to Section 6.4. The Emission 
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Control Plan shall identify all units subject to this rule. The Emission Control 

Plan shall identify steps to be taken to comply with this rule. 

 7.2.2 “Authority to Construct” identifies the date by with the operator shall submit 

an Application for Authority to Construct for each unit subject to the rule. 

 

 7.2.3 "Full Compliance" identifies the date by which the owner shall demonstrate 

that each unit is in compliance with this rule. 

 7.3 Any unit that is exempted under Section 4.2 that becomes subject to the emission 

limits of this rule through the loss of exemption status, shall be in full compliance 

with this rule on and after the date the exemption status is lost. 

 7.4 Any unit that becomes subject to the emission limits of this rule as a result of 

exceeding the applicable annual heat input limit specified in either Section 5.1.1 

Table 1 Category H or Section 5.2, shall be in compliance with the applicable 

standard option emission limits for Category A and B units in Section 5.1.1 on and 

after the date the annual heat input limit is exceeded. 

8.0 Calculations 

 8.1 All ppmv emission limits specified in Section 5.1 are referenced at dry stack gas 

conditions and 3.00 percent by volume stack gas oxygen. Emission concentrations 

shall be corrected to 3.00 percent oxygen as follows: 

measured

measured

corrected x [ppm NOx]

20 95. % [%O ]2

17 95. %

[ppm NOx]

−

= 

measured

measured

corrected x [ppmCO]

20 95. % [%O ]2

17 95. %

[ppmCO]

−

=

 8.2 All pounds per million Btu NOx emission rates shall be calculated as pounds of 

nitrogen dioxide per million Btu of heat input (hhv). 

9.0 Alternative Emission Control 

 9.1 General 

 The single owner of two or more units may comply with Section 5.1 by controlling 

units in operation at the same stationary source, or at two contiguous stationary 

sources, to achieve an aggregated NOx emission factor no higher than 90 percent of 

the aggregated NOx emission factor limit that would result if each unit in operation 

were individually in compliance with the applicable NOx emission limits in Section 

5.1. An operator that is subject to the AECP requirements below shall also comply 

with the applicable requirements of Sections 5.0, 6.0, 7.0 and 8.0. 
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 9.2 Eligibility 

 A unit not subject to Section 5.1 or Section 5.2.3 is not eligible for inclusion in an 

AECP. 

 9.3 Exclusion 

 No unit subject to Sections 5.2.1 or 5.2.2 shall be included in an AECP. 

 9.4 AECP Definitions 

 For the purposes of Section 9.0, the following definitions shall apply: 

9.4.1 Aggregated NOx emission factor limit: the sum of the NOx emissions, over 

seven consecutive calendar days, that would result if all units in the AECP 

were in compliance with the lb/MMBtu limits in Section 5.1 and operating at 

their actual firing rates, divided by the sum of the heat input of all units in the 

AECP over seven consecutive calendar days. Aggregated emission factor 

limit is calculated as: 

F

L F

L =

i

i i

A

Σ

Σ

 where: LA is the aggregated NOx emission factor limit (lb/MMBtu) 

 Li

 is the applicable NOx emission factor limit (lb/MMBtu) specified 

in Section 5.1.1 Table 1 or Section 5.1.2 for each category of unit in 

the AECP, 

 

 Fi is the total heat input (hhv basis) of fuel (MMBtu) combusted in 

each unit during seven consecutive calendar days, and 

 i identifies each unit in the AECP. 

 

9.4.2 Aggregated NOx emission factor: the sum of the actual NOx emissions 

during seven consecutive calendar days from all units in the AECP, divided 

by the sum of the heat input of all units in the AECP during seven 

consecutive calendar days. The aggregated emission factor is calculated as: 

 

F

E F

E =

i

i i

A

Σ

Σ

 where: EA

 is the aggregated NOx emission factor (lb/MMBtu), 
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 Ei is the NOx emission factor (lb/MMBtu) for each unit in the 

AECP, established and verified by source testing, or continuous 

emission monitors, 

 Fi is the total heat input (hhv basis) of fuel (MMBtu) combusted in 

each unit during seven consecutive calendar days, and 

 i identifies each unit in the AECP. 

 9.5 AECP Requirements 

 9.5.1 The aggregated NOx emission factor (EA) shall not exceed 90 

percent of the aggregated emission limit (LA

). The owner of any unit 

in an AECP shall notify the APCO within 24 hours of any violation 

of this section. 

EA

 must be< 0.90 x LA 

 9.5.2 Only units in the AECP which were operated during seven 

consecutive calendar days shall be included in the calculations of the 

aggregated NOx emission factor (LA) and the aggregated NOx 

emission limit (EA). 

 9.5.3 During each seven consecutive calendar days of operation that the 

AECP is used, the operator shall calculate and record the aggregated 

NOx emission factor (LA) and the aggregate NOx emission limit 

(EA). 

 9.5.4 The operator shall submit a NOx emission factor for each unit that is 

included in the AECP. The established NOx emission factor of the 

unit shall be no less than the emission factor of the unit from the 

most recent source test conducted pursuant to Section 6.3 and 

approved by the APCO. The operator shall not operate any AECP 

unit in such a manner that the NOx emissions exceed the established 

NOx emission factor of the unit. 

 9.5.5 The operator shall submit the AECP, for approval by the APCO, by 

June 1, 2004 or at least 24 months before compliance with the 

applicable emission limits in Section 5.1 is required pursuant to the 

Section 7.1, whichever is later. The AECP shall be submitted with 

an application for an Authority to Construct pursuant to complying 

with Section 7.1 as applicable. The operator shall obtain a written 

approval of the AECP from the APCO prior to implementation. 

9.6 AECP Administrative Requirements 
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 9.6.1 The AECP shall: 

 9.6.1.1 Contain all data, records, and other information necessary to 

determine eligibility of the units for alternative emission control, 

including but not limited to: 

 

 9.6.1.1.1 A list of units subject to alternative emission control, 

 9.6.1.1.2 Daily average and maximum hours of utilization for 

each unit, 

 9.6.1.1.3 Rated heat input of each unit, and 

 9.6.1.1.4 Fuel type for each unit. 

 9.6.1.2 Present the methodology for recordkeeping and reporting 

required by Sections 9.6.4 and 9.6.5. 

9.6.1.3 Specify which NOx limit, either Standard Option or Enhanced 

 Option, will be satisfied by the units under the AECP. 

9.6.1.4 Demonstrate that the aggregated emission factor will meet the 

 requirements of Section 9.5. 

 9.6.1.5 Demonstrate that the schedule for achieving AECP NOx 

emission levels is at least as expeditious as the schedule if 

applicable units were to comply individually with the applicable 

emission levels in Section 5.1 and the increments of progress in 

Section 7.0. 

 9.6.2 Revision of AECP 

 Owners shall demonstrate APCO approval of the AECP prior to applying 

for a modification to said AECP. 

 

 9.6.3 AECP Recordkeeping 

 In addition to the records kept pursuant to Section 6.1, the operator shall 

maintain records, on a daily basis, of the parameters needed to demonstrate 

compliance with the applicable NOx emission limits when operating under 

the AECP. The records shall be retained for at least five years and shall be 

made available to the APCO upon request. The records shall include, but 

are not limited to, the following: 

 

 9.6.3.1 For each unit included in the AECP the owner shall maintain the 

following records for each day: 

 

 9.6.3.1.1 fuel type and amount used for each unit (Fi

), 
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 9.6.3.1.2 the actual emission factor for each unit (Ei), 

 9.6.3.1.3 the total emissions for all units (ΣEiFi

), 

 9.6.3.1.4 the aggregated emission factor (EA), 

 9.6.3.1.5 the aggregated emission factor limit (LA), and 

 9.6.3.1.6 any other parameters needed to demonstrate daily 

compliance with the applicable NOx emissions when 

operating the units under the AECP. 

 

 9.6.4 Reporting and Annual Updates 

 Notifications of any violation pursuant to Section 9.5 shall include: 

 9.6.4.1 name and location of facility, 

 9.6.4.2 list of applicable units, 

 9.6.4.3 cause and expected duration of exceedance, 

 9.6.4.4 the amount of excess emissions, and 

 9.6.4.5 proposed corrective actions and schedule. 

 9.7 Compliance Schedule 

 The AECP schedule for achieving reduced NOx emission levels shall be at least as 

expeditious as the schedule if applicable units were to comply individually with the 

emissions limits specified in Sections 5.1.1 and 5.1.2 and the applicable compliance 

schedule required by Section 7.0. 

 
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