Imperial County Air Pollution Control District Rule 207

RULE 207 NEW AND MODIFIED STATIONARY SOURCE REVIEW

(Adopted prior to 3/17/80; Revised 9/7/93; 9/14/99; 10/22/2013)

A. General

A.1 Purpose:

A.1.a This Rule establishes preconstruction review requirements for new 

and modified Stationary Sources to ensure that the operation of 

such Sources do not interfere with the attainment or maintenance 

of Ambient Air Quality Standards (AAQS).

A.1.b This Rule shall provide for no net increase in emissions, pursuant 

to Health and Safety Code (H&SC) Section 40918, from new or 

modified Stationary Sources which emit or have the Potential to 

Emit 137 pounds per day or more of any Nonattainment Pollutant or 

their Precursors.

A.2 Applicability:

A.2.a This Rule shall apply to all new Stationary Sources and all 

Modifications to existing Stationary Sources which are subject to 

District permit requirements, and after Construction, emit or have 

the Potential to Emit one or more Affected Pollutants.

A.2.b Applications received by the District shall be subject to the 

requirements of this Rule in effect at the time such application is 

deemed complete, except when a more stringent new federal 

requirement not yet incorporated into this Rule shall apply to the 

new or modified Stationary Source.

A.2.c PUBLIC NOTIFICATION AND PUBLIC INSPECTION 

REQUIREMENTS: All applications for any new or modified 

Stationary Source or Emissions Unit shall be processed following 

the provisions of Rule 206, Processing of Applications, and shall be 

finalized by the Air Pollution Control Officer (APCO) only after being 

subject to the public notice and comment requirement of Rule 206.

A.2.d If any Source or Modification becomes a Major Stationary Source 

or Major Modification, as defined in this Rule, solely by virtue of a 

relaxation in any federally enforceable limitation which was

established after August 7, 1980, on a capacity of the Source or 

Modification to emit a federal Nonattainment Pollutant or its 

Precursor such as a restriction on hours of operation, then the 

requirements of this Rule shall apply to such a Source or 

Modification as though construction had not yet commenced on the 

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Source or Modification.

B. Definitions

The following definitions apply for all terms applicable to this Rule. If a term is 

not defined in this Rule, then the definitions provided in 40 Code of Federal 

Regulations (CFR) 51.165, as of July 1, 2012, shall apply.

ACTUAL EMISSIONS: measured or calculated emissions which most accurately 

represent the emissions from an Emissions Unit. Determination of Actual 

Emissions must be based on average actual production rates, fuel consumption 

and/or throughput rates from the last consecutive 24 months. Emission factors 

shall be established by Source testing or obtained from AP-42 or other approved 

sources.

ACTUAL EMISSIONS REDUCTIONS (AER): reductions of Actual Emissions 

from an Emissions Unit, calculated pursuant to Section E.2, which are Real, 

Quantifiable, Surplus, Permanent and Enforceable.

ACTUAL INTERRUPTIONS OF POWER: the interruption of electrical service by 

an unforeseeable event.

AFFECTED POLLUTANTS: pollutants for which an Ambient Air Quality Standard

(AAQS) have been established by the United States Environmental Protection 

Agency (US EPA) or the California Air Resources Board (CARB) and the 

Precursors to such pollutants, and those pollutants regulated by the US EPA 

under the Clean Air Act (CAA) or by the CARB under the H&SC, except for 

greenhouse gases and hazardous air pollutants, including but not limited to: 

Volatile Organic Compounds (VOC), nitrogen oxides (NOx), sulfur oxides (SOx), 

Particulate Matter with an aerodynamic diameter equal to or less than 10 

micrometers (PM10), Particulate Matter with an aerodynamic diameter equal to or 

less than 2.5 micrometers (PM2.5), carbon monoxide (CO), lead, fluorides, 

sulfuric acid mist, hydrogen sulfide, and total reduced sulfur compounds. The 

term Affected Pollutant shall not include any or all hazardous air pollutants either 

listed in Section 112 of the CAA or added to the list pursuant to Section 112(b)(2) 

of the CAA, and which have not been delisted pursuant to Section 112(b)(3) of 

the CAA, unless the listed hazardous air pollutant is also regulated as a 

constituent or Precursor of a general pollutant listed under Section 108 of the 

CAA.

AGRICULTURAL SOURCE: means a Source of air pollution or a group of 

Sources used in the production of crops, or the raising of fowl or animals located 

on Contiguous Property under common ownership or control that meets any of 

the following criteria;

1. is a Confined Animal Facility, including, but not limited to, any structure, 

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building, installation, barn, corral, coop, feed storage area, milking parlor, 

or system for the collection, storage, treatment, and distribution of liquid 

and solid manure, if domesticated animals, including, but not limited to, 

cattle, calves, horses, sheep, goats, swine, rabbits, chickens, turkeys, or 

ducks are corralled, penned, or otherwise caused to remain in restricted 

areas for commercial agricultural purposes and feeding is by means other 

than grazing.

2. is an Internal Combustion Engine used in the production of crops or the 

raising of fowl or animals, including, but not limited to, an engine subject to 

Article 1.5 (commencing with Section 41750) of Chapter 3 of Part 4 of 

Division 26 of the H&SC, except an engine that is used to propel 

implements of husbandry.

3. is a Title V Source or is a Source that is otherwise subject to regulation by 

the District or the CAA.

AIR POLLUTION CONTROL OFFICER (APCO): the person appointed by the Air 

Pollution Control Board and assigned to manage and direct the business and 

operations of the District, or their designee.

AMBIENT AIR QUALITY STANDARDS (AAQS): for the purposes of this Rule, 

Ambient Air Quality Standards (AAQS) shall be interpreted to include State and 

National AAQS. For the purposes of submittal of this Rule to the US EPA for 

inclusion in the California State Implementation Plan (SIP) all references in this 

Rule to AAQS shall be interpreted as National AAQS.

AUTHORITY TO CONSTRUCT: a written permit issued by the District for the 

Construction, installation, assembly, Modification, or replacement of any facility, 

article, machine, Equipment, or other contrivance.

BEST AVAILABLE CONTROL TECHNOLOGY (BACT): for any Emissions Unit 

the more stringent of:

1. the most effective emission Control Device, emission limit, or technique 

which has been achieved in practice for such class or category of Source.

2. any other alternative emission Control Device, emission control technique, 

basic Equipment, fuel, or process determined to be technologically 

feasible and cost-effective by the APCO. Cost-effectiveness analyses 

shall be performed in accordance with methodology and criteria specified 

in the Best Available Control Technology Guideline for the South Coast Air 

Quality Management District, or an alternative methodology and criteria 

acceptable to the APCO.

3. under no circumstances shall BACT be determined to be less stringent 

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than the emission control required by any applicable provision of law or 

regulation of the District, State and federal government, or the most 

stringent emissions limitation which is contained in the implementation 

plan of any State, unless the applicant demonstrates to the satisfaction of 

the APCO that such limitations are not technologically achievable. In no 

event shall the application of BACT result in the emissions of any pollutant 

which exceeds the emissions allowed by any applicable New Source 

Performance Standard (40 CFR, part 60) or National Emission Standard 

for Hazardous Air Pollutants (40 CFR, part 61 or part 63).

CARGO CARRIERS: Cargo Carriers are trains dedicated to a specific Stationary

Source. For purposes of this Rule, the term "trains dedicated to a specific 

Stationary Source" shall not include any train for which the prime mover is owned 

and operated by a common carrier, and by which cargo is delivered to or from 

the Stationary Source under a contract of common carriage. The emissions from 

all trains dedicated to a specific Stationary Source, while operating in the District, 

including directly emitted and Fugitive Emissions, shall be considered as 

emissions from the Stationary Source.

CLASS I AREA: any area listed as Class I in 40 CFR Part 81 Subpart D, 

including Section 81.405, or an area otherwise specified as Class I in the 

legislation that creates a national monument, a national primitive area, a national 

preserve, a national recreational area, a national wild and scenic river, a national 

wildlife refuge, a national lakeshore or seashore.

CLEAN AIR ACT (CAA): the Federal Clean Air Act (42 United States Code 

Section 7401 et seq.) and implementing regulations.

CODE OF FEDERAL REGULATIONS (CFR): the United States document 

codifying federal regulations.

COMPLETE APPLICATION: completeness of an application for an Authority to 

Construct a new or modified Emissions Unit shall be evaluated on the basis of a 

list of required information which has been adopted by the District.

CONSTRUCTION: any physical change or change in the method of operation 

(including fabrication, erection, installation, demolition, or Modification of an 

Emissions Unit) which would result in a change in emissions.

CONTIGUOUS PROPERTY: two or more Parcels of land with a common 

boundary or separated solely by a public or private roadway or other public 

right-of-way.

CONTROL DEVICE: any device for reducing emissions into the Atmosphere.

CONTROL EQUIPMENT: air pollution Control Equipment that eliminates, 

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reduces or controls the issuance of air emissions.

DAILY EMISSIONS LIMIT: one or a combination of permit conditions, specific to 

an Emissions Unit, which restricts its maximum daily emissions, in pounds per 

day, at or below the emissions associated with the maximum design capacity. A 

daily emissions limit must be:

1. contained in and Enforceable by the latest Authority to Construct or the 

latest Permit to Operate for the Emissions Unit, and

2. Enforceable on a daily basis, and

3. established pursuant to a permitting action occurring after September 7, 

1993.

DISTRICT: the Imperial County Air Pollution Control District (ICAPCD).

EMISSION REDUCTION CREDITS (ERC’s): reductions of Actual Emissions 

from an Emissions Unit that are registered with the District in accordance with the 

requirements of Rule 214.

EMISSION INCREASE: means any increase in a Stationary Source or an 

Emissions Unit’s Potential to Emit, calculated pursuant to Section E.3 of this 

Rule.

EMISSIONS UNIT: an identifiable operation or piece of process Equipment, such 

as an article, machine, or other contrivance, which emits, has the Potential to 

Emit, or results in the emissions of any air pollutant directly or as Fugitive 

Emissions.

ENFORCEABLE: means certain actions which are assured by verifiable and 

legally binding conditions in an Authority to Construct and/or Permit to Operate. 

EQUIPMENT: includes any article, machine, or contrivance that emits, has the 

Potential to Emit, or reduces emissions of any air pollutant emitted directly or as 

Fugitive Emissions.

ERC: see Emission Reduction Credits.

FEDERAL LAND MANAGER: the Secretary of the Department with authority 

over the specified federal lands.

FLUORIDES: elemental fluorine and all fluoride compounds.

FUGITIVE EMISSIONS: those emissions which cannot reasonably pass through 

a stack, chimney, vent, or other functionally equivalent opening.

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HALOGENATED HYDROCARBONS: all Halogenated Hydrocarbons listed as 

exempt under the definition of Volatile Organic Compounds.

HEALTH AND SAFETY CODE (H&SC): "Health and Safety Code" refers to the 

California Health and Safety Code.

HISTORIC ACTUAL EMISSIONS: Actual Emissions from an existing Emissions 

Unit averaged over a 24 month period immediately preceding the date of 

application. The APCO may approve another 24 month period within the last 60 

months, if the APCO determines that the other period is more representative of 

normal operations. Where an Emissions Unit has been in operation for less than 

24 months a shorter averaging period of at least 12 months may be used 

providing it represents the full operational history of the Emission Unit. The 

Historic Actual Emissions from Emission Units which have been in operation for 

less than 12 months shall be equal to zero. Historic Actual Emissions are to be 

calculated in pounds per quarter for each calendar quarter. Historic Actual 

Emissions in quarters 2 or 3 may be lowered by transferring these emissions to 

quarters 1 or 4, provided that the resulting emissions in quarters 1 or 4 are no 

higher than the higher of quarters 2 or 3. 

IDENTICAL REPLACEMENT UNIT: a replacement Emissions Unit which is the 

same as the original unit in all respects except for the serial number.

MAJOR MODIFICATION: a Modification to a Major Stationary Source which 

results in a Significant Emission Increase and a Significant Net Emission 

Increase of the pollutant for which the Stationary Source is classified as a Major 

Stationary Source.

MAJOR STATIONARY SOURCE: means a Stationary Source which emits, or 

has the Potential to Emit 100 tons per year (tpy) or more of Volatile Organic 

Compounds or Oxides of Nitrogen, or 70 tpy or more of PM10, or a PM10

Precursor or 100 tpy or more of PM2.5 or a PM2.5 Precursor. In addition, any 

physical change occurring at a Stationary Source which is not already a Major 

Stationary Source, and which Modification would constitute a Major Stationary 

Source by itself, makes the Source a Major Stationary Source.

MODIFICATION: any physical change, change in method of operation of, or 

addition to, an existing Emissions Unit, or any change in hours of operation or 

production rate which would necessitate a change in permit conditions.

Unless previously limited by a permit condition, the following shall not be 

considered a Modification:

1. change in ownership of an existing Stationary Source with valid Permit(s) 

to Operate.

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2. routine maintenance or repair.

3. an Identical Replacement Unit, if the Modification does not result in a 

Major Modification.

A Modification of an Emissions Unit also occurs when there is an increase in 

emissions from such a unit caused by a Modification of the Stationary Source 

and the Emissions Unit is not subject to a Daily Emissions Limit. 

A Modification to a Stationary Source shall include any Modification of its 

permitted Emissions Unit(s) or the addition of any new Emissions Unit(s).

A Reconstructed Stationary Source shall be treated as a new Stationary Source 

and not as a Modification.

NONATTAINMENT AREA: an area designated by a State or federal agency as 

exceeding a State or National Ambient Air Quality Standard.

NONATTAINMENT POLLUTANT: any pollutant or Precursor which has been 

designated "nonattainment" by the US EPA as codified in 40 CFR Section 81.305 

or that has been designated “nonattainment” by the CARB pursuant to H&SC 

Section 39607.

OFFSET: the use of an emission decrease to compensate for an Emission 

Increase from a new or modified Stationary Source subject to the requirements of 

Rule 207.

PARTICULATE MATTER: any material, except uncombined water, which exists 

in a finely divided form as a liquid or solid at standard conditions. Dust shall also 

be considered as Particulate Matter.

PARTICULATE MATTER (PM10): Particulate Matter with an aerodynamic 

diameter equal to or less than 10 micrometers. Gaseous emissions which 

condense to form Particulate Matter at ambient temperatures shall be included.

PARTICULATE MATTER (PM2.5): Particulate Matter with an aerodynamic 

diameter equal to or less than 2.5 micrometers. Gaseous emissions which 

condense to form Particulate Matter at ambient temperatures shall be included.

PERMANENT: the actual emission reductions that continue or endure for the 

duration of any Project utilizing the resulting ERC’s as Offsets. 

PERMIT TO OPERATE: the written permit issued by the District for the operation 

of any facility, article, machine, Equipment, Emission Unit or other contrivance.

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PERSON: any person, firm, association, organization, partnership, business 

trust, corporation, company, limited liability company, contractor, supplier, 

installer, user or owner, or any federal, State or local government agency, public 

district, or any officer or employee thereof. 

PM2.5 NONATTAINMENT AREA: that portion of Imperial County which lies within 

the line described as follows: (San Bernardino Base and Meridian) Beginning at 

the intersection of the United States-Mexico Border and the southeast corner of 

T17S R11E, then north along the range line of the eastern edge of range R11E, 

then east along the township line of the southern edge of T12S to the northeast 

corner of T13S R15E, then south along the range line common to R15E and 

R16E, to the United States-Mexico border.

POTENTIAL EMISSIONS: the sum of the maximum emissions from all 

Emissions Units at a Stationary Source, based on the maximum design capacity, 

unless otherwise limited by practically and legally Enforceable conditions 

contained in the Authority to Construct and/or Permit to Operate, expressed in 

terms of pounds per quarter. (Pounds per quarter for PM10, PM2.5 and sulfur 

oxides shall be determined by multiplying the Daily Emission Limit, in pounds per 

day, by the permitted operating days per quarter.)

POTENTIAL TO EMIT: the maximum capacity of an Emissions Unit to emit an 

Affected Pollutant based on its physical and operational design. Any physical or 

operational limitation on the capacity of the Emissions Unit to emit a pollutant, 

including air pollution Control Equipment and restrictions on hours of operation or 

on the type or amount of material combusted, stored, or processed, shall be 

treated as part of its design only if the limitation or the effect it would have on 

emissions is incorporated into the applicable permit as a practically and legally 

Enforceable permit condition.

PRECURSOR: a directly emitted Affected Pollutant that, when released into the 

Atmosphere, forms or causes to be formed or contributes to the formation of a 

secondary pollutant for which a State or National AAQS has been adopted, or 

whose presence in the Atmosphere will contribute to the violation of one or more 

State or National AAQS. The following Precursor secondary pollutant 

relationships shall be used for the purposes of this Rule:

PRECURSORS SECONDARY POLLUTANTS

Hydrocarbons and substituted a) Photochemical Oxidant (Ozone)

hydrocarbons (Volatile Organic b) The organic fraction of PM10

Compounds). c) Organic fraction of PM2.5, if 

Volatile Organic Compounds are

determined to be a necessary part 

of the PM2.5 control strategy in the 

attainment demonstration 

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approved by the US EPA in the 

SIP

Nitrogen Oxides (NOx) a) Nitrogen Dioxide (NO2)

b) The nitrate fraction of PM10

c) Photochemical Oxidant (Ozone)

d) The nitrate fraction of PM2.5

Sulfur Oxides (SOx) a) Sulfur Dioxide (SO2)

b) Sulfates (SO4)

c) The sulfate fraction of PM10

d) The sulfate fraction of PM2.5

Ammonia a) Organic fraction of Nitrate, if 

ammonia is determined to be a 

necessary part of the PM2.5

control strategy in the attainment 

demonstration approved by the

US EPA in the SIP

PROJECT: activity, for which a permit is required, or that has the Potential to 

Emit Air Contaminants. A Project includes all of the Emission Units associated 

with the scope of the preconstruction application for a new or modified Stationary 

Source and any Emissions Unit(s) indirectly affected.

PROPOSED EMISSIONS: the Potential to Emit for a new or post Modification 

Emissions Unit.

QUANTIFIABLE: means a reliable, replicable and accurate basis for calculating 

the amount, rate, nature and characteristic of an emission reduction by adhering 

to a quantification protocol that can be established considering US EPA, CARB 

and District policies and procedures. 

QUARTERLY: the calendar quarter beginning on January 1, April 1, July 1, and 

October 1.

REAL: a "real" emission reduction means that actual air emissions are reduced 

and that they are actually occurring and not artificially devised.

REASONABLY AVAILABLE CONTROL TECHNOLOGY (RACT): is the most 

stringent of the following control options:

1. the most effective emission limits in existing regulations that are currently 

in effect in any District whose nonattainment status is designated as 

moderate, with such limits resulting from the application of retrofit 

technologies judged by the APCO to be demonstrated and reliable.

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2. emission limits identified in existing Suggested Control Measures (SCM’s), 

model rules, the US EPA’s Control Techniques Guidelines (CTG’s) or 

other such documents.

3. emission limits in new (post 1988) SCM’s and the technical review group 

of the California Air Pollution Control Officers Association approved 

Reasonably Availability Control Technology/Best Available Retrofit Control 

Technology (RACT/BARCT) determinations, which are not identified as 

BACT and are less stringent than BACT.

4. the lowest emission limit that can be achieved by the specific Source by 

the application of control technology taking into account environmental 

impacts, technological feasibility, cost-effectiveness, and the specific 

design features or extent of necessary Modifications to the Source. 

Emission limits for existing specific Sources may be found in the field 

studies and evaluations of District regulations conducted by the US EPA 

and the CARB.

5. the lowest emission limit achieved for the Source category that is 

technically feasible, economically reasonable and achieved in practice 

anywhere (including outside the United States), with such limits resulting 

from the application of retrofit control technologies judged by the APCO to 

be demonstrated and reliable.

6. any combination of control technologies that will achieve emission 

reductions equivalent to that resulting from the most stringent option listed 

above.

RECONSTRUCTED STATIONARY SOURCE: any Stationary Source undergoing 

physical Modification where the fixed capital cost of the new components 

exceeds 50 percent of the fixed capital cost of a comparable entirely new 

Stationary Source. Fixed capital cost means that capital needed to provide all 

the depreciable components.

RULE: a Rule of the Air Pollution Control District of Imperial County.

SHUTDOWN: means an action necessary to cease operation of an Emissions

Unit and includes the amount of time needed to safely do so. For the purposes 

of calculating ERC’s, means the Permanent cessation of emissions from an 

emitting unit and the surrender of the operating permit.

SIGNIFICANT: in reference to an Emission Increase or the potential of a Source 

to emit any of the following pollutants, a rate of emissions that would equal or 

exceed any of the following rates:

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1. PM2.5: 10 tpy of direct PM2.5 or 40 tpy of sulfur dioxide emissions or 40 tpy 

of nitrogen oxide emissions.

2. Nitrogen oxides: 40 tpy;

3. Sulfur dioxide: 40 tpy;

4. VOC’s: 40 tpy; and

5. PM10: 15 tpy.

SIGNIFICANT EMISSION INCREASE: an increase in emissions that is 

Significant for that pollutant.

SIGNIFICANT NET EMISSION INCREASE: an increase in net emissions that is 

Significant for that pollutant. The “net emission increase” shall be determined as 

defined in 40 CFR 51.165.

SOURCE: a specific device, article, or piece of Equipment from which Air 

Contaminants are emitted, or the distinct place (such as with fires or other 

chemical activity) from which Air Contaminants are emitted. A Project or facility 

may have more than one Source and the term may be used to describe a group 

of "Sources."

STATIONARY SOURCE: any building, structure, facility, Equipment, or 

Emissions Unit which emits or may emit any Affected Pollutant directly or as a 

Fugitive Emission. Building, structure, or facility includes all pollutant emitting 

activities, including Emission Units, which:

1. are located on one or more contiguous or adjacent properties, and

2. are under the same or common ownership or operation, or which are 

owned or operated by entities which are under common control, and

3. belong to the same industrial grouping either by virtue of falling within the 

same two-digit standard industrial classification code or by virtue of being 

part of a common production process, industrial process, manufacturing 

process, or connected process involving a common raw material.

SURPLUS: the amount of emission reductions that are, at the time of generation 

of an ERC, not otherwise required by federal, State, or local law, not required by 

any legal settlement or consent decree, and not relied upon to meet any 

requirement related to the California SIP. For the purposes of Sections C.2.c 

and C.2.d, “Surplus” means the amount of emission reductions that are, at the 

time of use of an ERC, not otherwise required by federal, State, or local law, not 

required by any legal settlement or consent decree, and not relied upon to meet 

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any requirement related to the California SIP. However, emission reductions 

required by a State statute that provides that the subject emission reductions 

shall be considered Surplus may be considered Surplus for purposes of this Rule 

if those reductions meet all other requirements of this section. Examples of 

federal, State, and local laws and of SIP-related requirements include, but are 

not limited to, the following:

1. the federally-approved California SIP;

2. other adopted State air quality laws, and regulations not in the SIP, 

including but not limited to, any requirement, regulation, or measure that: 

(1) the District or the State has included on a legally-required and publiclyavailable list of measures that are scheduled for adoption by the District or 

the State in the future; or (2) is the subject of a public notice distributed by 

the District or the State regarding an intent to adopt such revision;

3. any other Source or Source-category specific regulatory or permitting 

requirement, including, but not limited to, RACT, New Source 

Performance Standards (NSPS), National Emission Standards for 

Hazardous Air Pollutants (NESHAP), Best Available Control Measures 

(BACM), BACT, and the Lowest Achievable Emission Rates (LAER); and

4. any regulation or supporting documentation that is required by the CAA 

but is not contained or referenced in 40 CFR Part 52, including but not 

limited to: assumptions used in attainment and maintenance 

demonstrations (including Reasonable Further Progress demonstrations 

and milestone demonstrations), including any proposed control measure 

identified as potentially contributing to an Enforceable near-term 

emissions reduction commitment; assumptions used in conformity 

demonstrations, and assumptions used in emissions inventories.

5. emission reductions produced by monies from any public air quality 

related funding program including but not limited to the Carl Moyer 

Memorial Air Quality Standards Attainment Program and the vehicle 

registration surcharge fee.

TOTAL REDUCED SULFUR COMPOUNDS: the sulfur compounds methyl 

mercaptan, dimethyl sulfide, dimethyl disulfide, carbon disulfide, and carbonyl 

sulfide.

TRANSFER: in reference to ERC’s, means the conveyance of an ERC from one 

entity to another.

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY (US EPA): the 

Administrator or appropriate delegate of the "United States Environmental 

Protection Agency."

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VOLATILE ORGANIC COMPOUND (VOC): any volatile compound containing at 

least one atom of carbon, excluding carbon monoxide, carbon dioxide, carbonic 

acid, metallic carbides or carbonates, and ammonium carbonate, and excluding 

the following:

1. Methane;

methylene chloride (dichloromethane);

1,1,1-trichloroethane (methyl chloroform);

trichlorofluoromethane (CFC-11);

dichlorodifluoromethane (CFC-12);

1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113);

1,2-dichloro-1,1,2,2-tetrafluoroethane (CFC-114);

chloropentafluoroethane (CFC-115);

chlorodifluoromethane (HCFC-22);

2,2-dichloro-1,1,1-trifluoroethane (HCFC-123);

2-chloro-1,1,1,2-tetrafluoroethane (HCFC-124);

1,1-dichloro-1-fluoroethane (HCFC-141b);

1-chloro-1,1-difluoroethane (HCFC-142b);

trifluoromethane (HFC-23);

pentafluoroethane (HFC-125);

1,1,2,2-tetrafluoroethane (HFC-134);

1,1,1,2-tetrafluoroethane (HFC-134a);

1,1,1-trifluoroethane (HFC-143a);

1,1-difluoroethane (HFC-152a);

cyclic, branched, or linear completely methylated siloxanes;

the following classes of perfluorocarbons:

(A) cyclic, branched, or linear, completely fluorinated alkanes;

(B) cyclic, branched, or linear, completely fluorinated ethers with no 

unsaturations;

(C) cyclic, branched, or linear, completely fluorinated tertiary amines 

with no unsaturations; and

(D) sulfur-containing perfluorocarbons with no unsaturations and with 

the sulfur bonds only to carbon and fluorine; and

2. the following low-Reactive Organic Compounds which have been 

exempted by the US EPA:

acetone;

ethane;

parachlorobenzotrifluoride (1-chloro-4-trifluoromethyl benzene);

perchloroethylene;

methyl acetate; 

propylene carbonate and 

dimethyl carbonate

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3. Perfluorocarbon and Methylated Siloxane compounds shall be assumed to 

be absent from any product or process unless the manufacturer or 

operator indicates which specific, individual compounds from these broad 

classes are present, indicated the amount(s) present, and demonstrates 

the availability of a test method approved by the US EPA, the CARB, and 

the District for verifying the amount(s) present quantitatively.

4. Tertiary-Butyl Acetate (also known as t-butyl acetate, TBAC or TBAc) shall 

be considered exempt as a VOC only for purposes of VOC emissions 

limitations or VOC content requirements, but will continue to be a VOC for 

purposes of all recordkeeping, emissions reporting, photochemical 

dispersion modeling, and inventory requirements with apply to VOCs.

C. Standards

C.1 Best Available Control Technology (BACT)

C.1.a An applicant shall apply (BACT) on a pollutant by pollutant basis to 

any new Emissions Unit with a Potential to Emit of 25 pounds per 

day or more of any Nonattainment Pollutant or its Precursors. For 

PM2.5 this provision applies only to Emissions Units located in the 

PM2.5 Nonattainment Area of Imperial County.

C.1.b An applicant shall apply (BACT) on a pollutant by pollutant basis to 

any modified Emissions Unit with a Potential to Emit of 25 pounds 

per day or more of any Nonattainment Pollutant or its Precursors. 

For PM2.5 this provision applies only to Emissions Units located in 

the PM2.5 Nonattainment Area of Imperial County.

C.1.c An applicant shall apply BACT to any new or modified Emissions 

Unit with a Potential to Emit equal to or greater than the following:

POLLUTANT LBS/DAY

Carbon monoxide (CO attainment areas only)............. 550

Lead.................................................................. 3.3

Fluorides................................................................... 16

Sulfuric Acid Mist....................................................... 38

Hydrogen Sulfide....................................................... 55

Total Reduced Sulfur Compounds.............................. 55

BACT shall be applied for each pollutant(s) for which a threshold is 

exceeded. For the purpose of submittal of Rule 207 to the US EPA 

for inclusion in the California SIP, this Subsection shall not be 

included.

C.1.d For projects to be constructed in phases, the BACT determination 

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Imperial County Air Pollution Control District Rule 207

for Equipment to be added or modified in each phase shall be 

reevaluated no more than 18 months prior to the commencement of 

construction of that phase of the project. If it is determined that 

current BACT will result in lower emissions than previously 

determined, then current BACT shall be applied. Equipment which 

was installed during prior phases and which will not be modified 

during the current phase shall not be subject to the redetermination 

of the BACT.

C.1.e Cargo Carriers shall not be required to implement BACT.

C.1.f BACT shall not be required for any new Emissions Unit or 

Modification of an existing Emissions Unit used solely for the 

purpose of compliance with District, State, or federal air pollution 

control laws, regulations, or orders, as approved by the APCO, 

provided there is no increase in the permitted production rate, 

operating schedule, or maximum Equipment rating; and the new or 

modified Emissions Unit does not result in a new Major Stationary 

Source or Major Modification. This exemption applies only to the

primary pollutant for which compliance with District, State, or 

federal air pollution control laws, regulations, or orders is required. 

The APCO shall require the use of RACT for control of consequent 

pollutants that are the direct result of the use of an abatement 

device or emission reduction techniques implemented to comply 

with the BACT requirements for control of another pollutant.

C.1.g BACT shall not be required for any Modification of an existing 

Emissions Unit used for voluntary emission reductions for the sole 

purpose of generating ERC’s. This exemption applies only to the 

pollutant for which ERC’s are obtained.

C.1.h For emergency standby Equipment which meets the requirements 

of Section C.2.g, only those emissions which occur during routine 

operation of the Equipment for maintenance purposes shall be 

considered for the purpose of determining if the application of 

BACT is required for the emergency standby Equipment.

C.2 Offset Requirements General: Offsets are Actual Emission Reductions

(AER’s), calculated pursuant to Section E of this Rule, sufficient to Offset 

Emission Increases from a new or modified Emissions Unit. A new or 

modified Emissions Unit subject to the Offset requirements of this Rule 

shall provide Offsets for each calendar quarter as specified in Subsection 

C.3. The quantity of emissions to be offset shall be based on an initial 

estimate of proposed Emission Increases for the Project. The APCO shall 

require the use of acceptable methods to accurately estimate the 

emissions from the proposed Project, and shall require acceptable 

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Imperial County Air Pollution Control District Rule 207

methods to measure those emissions once the Source is operating.

C.2.a Offsets shall be required for any new or modified Stationary Source 

with a daily Potential to Emit, calculated pursuant to Subsection 

E.3, equal to or exceeding the following:

For the purpose of submittal of Rule 207 to the US EPA for 

inclusion in the California SIP, Subsection C.2.a shall not be 

included.

C.2.b A new Stationary Source or Modification of an existing Stationary 

Source which, on or after September 7, 1993, will result in a 

Potential to Emit for the Stationary Source of 137 pounds per day 

or more of nitrogen oxides, Volatile Organic Compounds, carbon 

monoxide, sulfur oxides, or PM10, shall Offset all Emission 

Increases, including Cargo Carrier and Fugitive Emissions, which 

cause the Stationary Source Potential to Emit to exceed 137 

pounds per day of nitrogen oxides, Volatile Organic Compounds, 

carbon monoxide, sulfur oxides, or PM10. For the purpose of 

submittal of Rule 207 to the US EPA for inclusion in the California 

SIP, Subsection C.2.b shall not be included.

C.2.c Major Stationary Source Requirement to Provide Offsets: A 

Stationary Source whose Project emissions will result in a new 

Major Stationary Source determination shall Offset all Emission 

Increases from the Project for each Nonattainment Pollutant that 

constitutes a Major Stationary Source. For PM2.5, this provision 

applies only to Stationary Sources located in the PM2.5

Nonattainment Area of Imperial County.

C.2.d Major Modification to a Major Stationary Source Requirement to 

Provide Offsets: A Modification of an existing Major Stationary 

Source whose Project emissions will result in a Major Modification 

shall Offset all Emission Increases that constitutes a Major 

Modification. For PM2.5, this provision applies only to Stationary 

Sources located in the PM2.5 Nonattainment Area of Imperial 

County.

C.2.e The PM10 emissions from an existing Stationary Source shall be 

POLLUTANT LBS/DAY

Volatile Organic Compounds ...................... 137

Nitrogen Oxides ...................................................... 137

Sulfur Oxides .......................................................... 137

PM10 ....................................................................... 137

Carbon Monoxide (See Section C.2.h.).................... 137

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Imperial County Air Pollution Control District Rule 207

calculated using applicable PM10 emission factors.

C.2.f In no case shall Halogenated Hydrocarbons be used as Offsets for 

Volatile Organic Compounds.

C.2.g The APCO may exempt an applicant from the requirements of 

Sections C.2 and C.3 of this Rule for Equipment to be used 

exclusively as emergency standby Equipment for non-utility 

electrical power generation and not used in conjunction with any 

utility voluntary demand reduction program, provided:

C.2.g.1 Operation for maintenance purposes is limited to 100 hours 

per year, and such maintenance shall be scheduled in 

cooperation with the District so as to have no adverse air 

quality impact, and to maintain Reasonable Further 

Progress, and operation of diesel engines may be further 

limited by the CARB’s Airborne Toxic Control Measure for 

Stationary Compression Engines pursuant to H&SC 

Section 93115.6(a), and

C.2.g.2 Operation for other than maintenance purposes shall be 

limited to Actual Interruptions of Power by the serving 

utility. Appropriate record keeping shall be required to 

verify and maintain this exemption.

C.2.h Offsets for carbon monoxide emissions from Sources located in 

carbon monoxide attainment areas shall not be required if the 

applicant demonstrates to the satisfaction of the APCO, pursuant to 

Section F of this Rule, that the carbon monoxide Emission 

Increases will not cause or contribute to a violation of AAQS.

C.2.i Upon approval by the APCO, an exemption from Sections C.2.a 

and C.2.b, shall be allowed, provided BACT is utilized, for the 

following subject permit units:

C.2.i.1 Abrasive Blasting Equipment, which has been registered 

under the Statewide Portable Equipment Registration 

Program (PERP).

C.2.i.2 Air Pollution Control Devices: Emission Increases, which 

do not result in a new Major Stationary Source or Major 

Modification, from an Emissions Unit that results from the 

installation, operation or other implementation of any 

emission Control Device or technique used to comply with 

a District, State, or federal emission control requirement, 

including, but not limited to, requirements for the use of 

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Imperial County Air Pollution Control District Rule 207

RACT or Best Available Retrofit Control Technology 

(BARCT), unless there is a Modification that results in an

increase in the capacity of the unit being controlled.

C.2.i.3 Emergencies: Emergencies which comply with the 

provisions of the Hearing Board Procedures for which 

Offsets are not required under those procedures.

C.2.j Except for Major Stationary Sources or Major Modifications, 

Agricultural Sources required to obtain a District permit shall be 

exempted from obtaining emission Offsets for any pollutant emitted 

from a particular Source, if the emissions from that Source would 

not meet the criteria necessary for creating Real, Permanent, 

Quantifiable, and Enforceable emission reductions.

C.3 Location of Offsets and Offset Ratios:

C.3.a A new or modified Stationary Source subject to the Offset 

requirements of this Rule shall provide Offsets for each calendar 

quarter equal to the Emission Increase for each calendar quarter, 

calculated in accordance with Section E of this Rule, and multiplied 

by using the appropriate Offset ratio listed in the following table:

LOCATION Offset RATIO

Within the same Source 1 to 1

Within 50 miles of the Source 1.2 to 1

More than 50 miles from the 

Source, and within air basin

No greater than 3 to 1 or 

less than 1.2 to 1, as 

necessary to assure the 

Stationary Source will not 

prevent or interfere with the 

attainment or maintenance 

of any AAQS

C.3.b The APCO may impose, based on the air quality analysis, a higher 

Offset ratio such that the new or modified Stationary Source will not 

prevent or interfere with the attainment or maintenance of any 

AAQS.

C.3.c Offsets shall be obtained from emission Sources located within the 

same Nonattainment Area within the District as the proposed 

Source or an emission Source that is located in the same air basin 

and in a Nonattainment Area with equal or worse nonattainment 

status.

C.4 Offset Requirements:

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Imperial County Air Pollution Control District Rule 207

C.4.a Offsets which are obtained to meet the requirements of Sections 

C.2 and C.3 from an air district other than that in which the 

proposed Source is located, but within the same air basin, may be 

used only if the APCO has reviewed the permit conditions issued 

by the air pollution control district in which the proposed Offsets are 

obtained and certifies that such Offsets meet the requirements of 

H&SC Section 40709.6 and this Rule and will not be used as 

mitigation for any other new or modified Emissions Unit(s). IntraDistrict Offsets used to meet Major Stationary Source Offset 

requirements shall be approved by the US EPA.

C.4.b Interpollutant Offsets, including interpollutant trades between PM10

and PM10 Precursors, may be approved by the APCO on a 

case-by-case basis, provided that the trade is technically justified 

and that the applicant demonstrates to the satisfaction of the APCO 

that the emissions from the new or modified Source will not cause 

or contribute to a violation of an AAQS. The APCO shall, based on 

an air quality impact analysis, impose Offset ratios equal to or 

greater than those required in Section C.3 of this Rule. PM10

emission reductions shall not be allowed to Offset nitrogen oxide or 

Volatile Organic Compound Emission Increases in ozone 

Nonattainment Areas. PM10 emission reductions shall not be 

allowed to Offset sulfur oxide Emission Increases in sulfate 

Nonattainment Areas. Interpollutant Offsets between PM2.5 and 

PM2.5 Precursors are only allowed at specific ratios as approved 

into the SIP by the US EPA. Interpollutant Offsets used to meet 

federal Nonattainment Area Offset requirements shall be approved 

by the US EPA.

C.4.c Offsets for new or modified Stationary Sources shall occur during 

the same annual time period as the Stationary Source will operate.

C.4.d Source Shutdowns or permanent curtailments in production or 

operating hours occurring before an application for an ERC is filed 

per Rule 214 may not be used as Offsets.

C.5 Additional Source Requirements:

C.5.a Alternative Siting: The applicant shall prepare an analysis

functionally equivalent to the requirements of Division 13, Section 

21000 et. seq. of the Public Resources Code for Sources for which 

an analysis of alternative sites, sizes, and production processes is 

required under Section 173 of the CAA.

C.5.b Ambient Air Quality Standards:

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Imperial County Air Pollution Control District Rule 207

C.5.b.1 Emissions from a new or modified Emissions Unit shall not 

cause or make worse a violation of an AAQS.

C.5.b.2 Section F of this Rule shall be used to estimate the effects 

of a new or modified Emissions Unit. In making this 

determination the APCO shall take into account the 

increases in minor and secondary emissions as well as the 

mitigation of emissions through Offsets obtained pursuant 

to this Rule.

C.5.b.3 A new or modified Emissions Unit may be exempt from the 

provisions of Subsection C.5.b.2 provided that the new or 

modified Stationary Source is not subject to the public 

noticing requirements of Rule 206, Processing of 

Applications.

C.5.c Compliance By Other Owned, Operated, Or Controlled Sources: 

The Owner or Operator of a proposed new or modified Emissions 

Unit shall demonstrate to the satisfaction of the APCO that all 

Stationary Sources owned or operated by such Person (or by any 

entity controlling, controlled by, or under common control of such 

Person) in California which are subject to emission limitations, are 

in compliance or on a schedule for compliance with all applicable 

emission limitations and standards.

C.5.d Except for Major Stationary Sources or Major Modifications, 

Projects which burn municipal waste, landfill gas or digester gas 

shall also be reviewed consistent with H&SC Section 42314.1 and 

42315.

C.5.e Issuance of an Authority to Construct shall not relieve any Owner or 

Operator of the responsibility to comply fully with any applicable 

provision of the District portion of the California SIP and any other 

requirements under District, State or federal law.

D. Administrative Requirements

The following administrative requirements, in addition to other requirements 

specified in all applicable District Rules and regulations, shall apply to all 

applications for a new or modified Emissions Unit, except for the review of power 

plants 50 megawatts and greater. Power plants 50 megawatts and greater shall 

be subject to the administrative requirements of Section D.4.

D.1 Authority To Construct - General Conditions:

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Imperial County Air Pollution Control District Rule 207

D.1.a An Authority to Construct shall not be issued unless the new or 

modified Emissions Unit complies with the provisions of this Rule 

and all applicable District Rules and regulations.

D.1.b An Authority to Construct shall require a new or modified 

Emissions Unit be built in accordance with specifications and 

plans contained in the application and approved by the APCO.

D.1.c An Authority to Construct shall contain all conditions deemed 

necessary by the APCO to assure Construction and operation of 

an Emissions Unit in the manner assumed in making the analysis 

to determine compliance with this Rule and all applicable District 

Rules and regulations.

D.1.d An Authority to Construct shall include all conditions deemed 

necessary by the APCO to assure compliance with the Offset 

requirements of this Rule.

D.1.e An Authority to Construct permit shall include Daily Emission 

Limits which reflect applicable emission standards.

D.1.f The APCO shall consult with the Federal Land Manager on a 

proposed Major Stationary Source or Major Modification that may 

impact visibility in any Class I Area.

An Authority to Construct permit shall address the potential to 

impact air quality (including visibility) of any Class 1 federal area.

D.1.g Prior to approving an Authority to Construct for a new or modified 

Source which emits hazardous air emissions and which is located within 

1,000 feet from the outer boundary of a school site, the APCO shall 

implement the provisions of H&SC Section 42301.6 through 42301.9. For 

the purpose of submittal of Rule 207 to the US EPA for inclusion into the 

California SIP, Subsection D.1.g shall not be included.

D.2 Permit to Operate - General Conditions:

D.2.a A Permit to Operate shall require that a new or modified 

Emissions Unit be operated in the manner assumed in making the 

analysis to determine compliance with this Rule and all applicable 

District Rules and regulations and as conditioned in the Authority 

to Construct.

D.2.b A Permit to Operate shall include Daily Emission Limits which 

reflect applicable emission standards.

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Imperial County Air Pollution Control District Rule 207

D.2.c Prior to the issuance of a Permit to Operate the APCO shall make 

a determination that the Source complies with the conditions 

established in the Authority to Construct.

C.3 Offset Conditions:

D.3.a For any Stationary Source which provides emission Offsets, the 

Source’s Permit to Operate shall be subject to Enforceable permit 

conditions containing specific operational and Daily Emissions 

Limits, which ensure that the emission reductions are provided in 

accordance with the provisions of this Rule and shall continue for 

the reasonably expected life of the proposed Source which 

required Offsets. 

D.3.b Where the Source of Offsets is not subject to a permit, a written 

contract shall be required between the applicant for the Source 

requiring Offsets and the Owner or Operator of the Offset Source, 

which contract, by its terms, shall be subject to the approval of, 

and Enforceable by the APCO. The Offset permits and contracts 

shall be submitted to the CARB for review and comment. A 

violation of the emission limitation provisions of any such contract 

shall invalidate the contract and the applicant for the Source using 

the Offsets shall be required to provide new Offsets. For the 

purpose of submittal of Rule 207 to the US EPA for inclusion into 

the California SIP, Subsection D.3.b shall not be included.

D.3.c Offsets required as a condition of an Authority to Construct or a 

Permit to Operate shall be Enforceable requirements at the time 

of Authority to Construct issuance and shall be in effect no later 

than the date of initial operation of the new or modified Emissions 

Unit. Where a new or modified Emissions Unit requires a shakedown period, and is a replacement for an existing Emissions Unit, 

the APCO may allow a maximum of 90 days as a start-up period 

for simultaneous operation of the existing Emissions Unit and the 

replacement Emissions Unit.

D.3.d For Major Stationary Sources and Major Modifications which are 

constructed in phases, the Authority to Construct shall clearly 

identify each phase of the p Project, the Emissions Unit(s) to be 

added at each phase, and the permitted emissions associated 

with those Emissions Units. The initial Authority to Construct for 

the Project shall identify sufficient Offsets for all Project phases in 

order to confirm Project feasibility. The Offsets for each phase 

shall (1) be implemented prior to the initiation of construction of 

that phase, (2) shall remain in effect for the life of the Equipment 

installed in that phase, (3) shall meet the Rules and regulations in 

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Imperial County Air Pollution Control District Rule 207

effect at the time of initiation of construction for that phase, and 

(4) shall be reevaluated for consistency with local, State and 

federal requirements by the District not more than 18 months prior 

to the initiation of construction for that phase. The Permit to 

Operate for each phase of the p Project shall be issued 

separately, after the District finds that the above requirements, in 

addition to any other applicable requirements of these Rules and 

regulations, have been met.

D.4 Power Plants: This section shall apply to all power plants proposed to be 

constructed within Imperial County and for which a Notice of Intent (NOI) 

or Application for Certification (AFC) has been accepted by the California 

Energy Commission.

D.4.a Within 14 days of receipt of a NOI, the APCO shall notify the 

CARB and the California Energy Commission of the District's 

intent to participate in the NOI proceeding. If the District chooses 

to participate in the NOI proceeding, the APCO shall prepare and 

submit a report to the CARB and the California Energy 

Commission prior to the conclusion of the nonadjudicatory 

hearing specified in Section 25509.5 of the California Public 

Resources Code. That report shall include, at a minimum:

D.4.a.1 A specific preliminary determination of BACT for the 

proposed facility;

D.4.a.2 A preliminary discussion of whether there is substantial 

likelihood that the requirements of this Rule and all 

other District Rules and regulations can be satisfied by 

the proposed facility; and

D.4.a.3 A preliminary list of conditions which the proposed 

facility must meet in order to comply with this Rule or 

any other applicable District Rules or regulations.

The preliminary determinations contained in the report shall be as 

specific as possible within the constraints of the information 

contained in the NOI.

D.4.b Upon receipt of an application for certification for a power plant, 

the APCO shall conduct a determination of compliance review. 

This determination shall consist of a review identical to that which 

would be performed if an application for an Authority to Construct 

had been received for the power plant. If the information 

contained in the application for the certification does not meet the 

requirements of this Rule, the APCO shall, within 20 calendar 

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Imperial County Air Pollution Control District Rule 207

days of receipt of the application for certification, so inform the 

California Energy Commission, and the application for certification 

shall be considered incomplete and returned to the applicant for 

re-submittal.

D.4.c The APCO shall consider the application for certification to be 

equivalent to an application for an Authority to Construct during 

the determination of compliance review, and shall apply all 

provisions of this Rule which apply to applications for an Authority 

to Construct.

D.4.d The APCO may request from the applicant any information 

necessary for the completion of the determination of compliance 

review. If the APCO is unable to obtain the information, the 

APCO may petition the presiding Commissioner of the California 

Energy Commission for an order directing the applicant to supply 

such information.

D.4.e Within 180 days of accepting an application for certification as 

complete, as specified in Section D.4.b, the APCO shall make a 

preliminary decision on:

D.4.e.1 whether the proposed power plant meets the 

requirements of this Rule and all other applicable 

District regulations; and

D.4.e.2 in the event of compliance, what permit conditions will 

be required including the specific BACT requirements 

and a description of required mitigation measures.

D.4.e.3 The preliminary written decision under Subsection 

D.4.e shall be treated as a preliminary decision under 

Rule 206, Processing of Applications, and shall be 

finalized by the APCO only after being subject to the 

public notice and comment requirements of Rule 206. 

The APCO shall not issue a preliminary determination 

of compliance unless all requirements of this Rule are 

met.

D.4.f Within 240 days of accepting an application for certification as 

complete, as specified in Section D.4.b, the APCO shall issue and 

submit to the California Energy Commission a preliminary 

determination of compliance or, if such a determination cannot be 

issued, shall so inform the California Energy Commission. A 

determination of compliance shall confer the same rights and 

privileges as an Authority to Construct only when and if the 

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Imperial County Air Pollution Control District Rule 207

California Energy Commission approves the application for 

certification, and the California Energy Commission certificate 

includes all conditions of the final determination of compliance.

D.4.g Any applicant receiving a certificate from the California Energy 

Commission pursuant to this section and demonstrates 

compliance with all conditions related to air pollution of the 

certificate shall be issued a Permit to Operate by the APCO.

E. Calculations

E.1 Calculation Of Offsets Required: Calendar quarter calculations used for 

determining Offsets required shall be determined as follows:

E.1.a the daily Emission Increase multiplied by the number of permitted 

days in each calendar quarter; or

E.1.b the Potential to Emit on a Quarterly basis, provided that in 

addition to Daily Emissions Limits, the Authority to Construct and 

Permit to Operate contain Enforceable conditions which limit 

emissions from the Emissions Unit for each calendar quarter.

E.2 Calculation Of Actual Emissions Reductions (AER’s) To Be Used As 

Offsets: AER’s resulting from Modifications to existing Emissions Units 

shall be calculated based on emission reductions from the Historic Actual 

Emissions for that Emissions Unit. Only positive values so calculated may 

qualify as AER’s. Prior to use as Offsets, all AER’s must qualify for 

deposit into the District's Emissions Reduction Credit Bank, except for 

AERs used to Offset Emission Increases within the same source. AER 

calculations shall be adjusted based on the provisions of E.2.d.

E.2.a AER’s from the Shutdown of an Emissions Unit shall be 

calculated as follows:

AER’s = Historic Actual Emissions

E.2.b When the Modification consists solely of an application for new 

Control Equipment or implementation of a more efficient process, 

the AER’s shall be calculated as follows:

AER’s = Historic Actual Emissions minus post-Modification 

Potential to Emit

E.2.c AER’s from other Modifications shall be calculated as follows:

AER’s = Historic Actual Emissions minus the post Modification 

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Imperial County Air Pollution Control District Rule 207

Potential to Emit.

E.2.d AER’s shall meet the following criteria:

E.2.d.1 Shall be Real, Enforceable, Quantifiable, Surplus, and 

Permanent.

E.2.d.2 Shall be in excess of any emissions reduction which is 

(1) required or encumbered by any applicable laws, 

Rules, regulations, agreements, orders, or (2) attributed 

to a control measure noticed in the District for workshop, 

or (3) contained in an adopted District Plan, SIP or 

California Clean Air Act Attainment Plan applicable to the 

District.

E.2.d.3 Emission reductions attributed to a proposed control 

measure, may be re-eligible as an AER if for control 

measures not identified in a District Air Quality Plan or 

SIP, no Rule has been adopted within two years from the 

date of the latest public workshop notice.

E.2.d.4 Emission reductions achieved before the base year used 

in an attainment plan demonstration for that pollutant

must be included in the inventory as growth to be eligible 

for use.

E.3 Calculation of Stationary Source Potential to Emit: The Potential to Emit 

for a Stationary Source shall be equal to the sum of Potentials to Emit for 

Permits to Operate (or Authority to Construct for Emissions Units for which 

a Permit to Operate has not been issued) for each Emissions Unit within a 

Stationary Source.

F. Air Quality Impact Analysis

F.1 In no case shall emissions from a new or modified Emissions Unit, cause 

or make worse the violation of an AAQS. The APCO may require an 

applicant to use an air quality model to estimate the effects of a new or 

modified Emissions Unit. For the purpose of performing an air quality 

impact analysis the following shall apply:

F.1.a Air quality models shall be consistent with the requirements 

contained in the most recent edition of EPA's "Guidelines on Air 

Quality Models, 40 CFR 51 Appendix W", unless the APCO finds 

that such model is inappropriate for use. After making such a 

finding the APCO may designate an alternate model only after 

allowing for public comment and only with the concurrence of the 

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Imperial County Air Pollution Control District Rule 207

CARB and the US EPA. All Modeling costs associated with the 

siting of a new or modified Emissions Unit shall be borne by the 

applicant.

F.1.b In performing an air quality impact analysis, if the proposed stack 

height is higher than is dictated by good engineering practices, the 

actual height used for the purposes of Modeling shall be calculated 

in accordance with good engineering practices, as specified in 40 

CFR 51.100(ii).

207-27