United States Environmental Protection Agency

Region IX Air Division

Technical Support Document 

for

EPA’s Notice of Proposed Rulemaking

for the

California State Implementation Plan

as submitted by the California Air Resources Board

EPA’s Analysis of

Imperial County Air Pollution Control District’s

Rule 201, Permits Required

Rule 202, Exemptions

January 2011

Prepared by Joanne Wells

Approved by Gerardo Rios
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Imperial County Air Pollution Control District (ICAPCD)

Submitted Rules

• Rule 201, Permits Required, was originally adopted prior to October 15, 1979. The 

current rule revision was adopted on October 10, 2006 and was submitted on August 24, 

2007. This submittal was determined to be complete on September 17, 2007. There are 

no more recent submittals of this rule on which EPA has not acted.

• Rule 202, Exemptions, was originally adopted June 1, 1977, and revised September 7, 

1993 and September 14, 1999. Both of these revisions were submitted to EPA; however, 

EPA has not taken action on either of these submittals. Rule 202 was revised again on 

October 10, 2006 and submitted on August 24, 2007. This submittal was determined 

complete on September 17, 2007. There are no more recent submittals of this rule.

Applicable SIP Rules

• Rule 201, Permits Required - The SIP version of this rule was revised on September 14, 

1999, submitted on May 26, 2000 and approved into the SIP on January 3, 2007 (72 FR 

9).

• Rule 202, Exemptions - There is no SIP version of Rule 202; however, SIP Rule 103 also 

contains permit exemptions. Rule 103 was submitted to EPA on February 21, 1972 and 

approved into the SIP on May 31, 1972 (37 FR 10842).

Background

Imperial County is currently classified as a moderate non-attainment area for federal 8 hour 

ozone, a serious non-attainment area for PM10 and a non-attainment area for PM2.5. 

Agricultural operations are a significant source of air pollution throughout the state of California, 

including Imperial County. Historically, agricultural operations had been exempted from many 

regulatory requirements, including the need for air pollution permits. On September 22, 2003,

California Senate Bill 700 (SB 700) became law and removed the blanket permitting exemption 

for agricultural sources provided under California Health & Safety Code (CH&SC) section 

42310(e) and subjected large agricultural sources to various permit requirements.

ICAPCD was required to amend and adopt a number of rules to comply with the requirements of 

SB 700, including revisions to Rules 201 and 202. The state law also requires permits and 

emission mitigation for Large Confined Animal Facilities (LCAF) as defined by the California 

Air Resources Board (CARB). LCAF are addressed in ICAPCD Rules 217 – Large Confined 

Animal Facilities Permits Required and 420 – Beef Feedlots, which are referenced in Rule 201. 

However, Rules 217 and 420 are not evaluated by this Technical Support Document (TSD). 

Purposes of Rule and Rule Amendments

These rules were originally developed as part of the local agency’s New Source Review (NSR) 

permitting program. The following is a summary of changes from the current SIP versions of 

these rules. 

Rule 201 – Permits Required, identifies when and what permits a source must obtain prior to

construction and operation. In paragraph C, references are provided for other types of permits 
3

required by ICAPCD rules, other than NSR permits. The only change made to the SIP approved 

rule is: 

• Section 201.C, Other Permits, was revised to replace “Feedlot certificates” with a 

reference to the ”Large Confined Animal Facilities” permit found in Imperial County 

Rules 217 and 420. 

Rule 202 – Exemptions, identifies processes, articles, machines, equipment, or other 

contrivances for which an Authority to Construct (ATC) or Permit to Operate (PTO) is not 

required. Rule 202 also requires recordkeeping to verify and maintain any exemption.

The SIP approved version of this rule is Rule 103 – Exemptions, which was approved into the 

SIP on May 31, 1972. This rule was replaced locally on June 1, 1977, when the District adopted 

Rule 202 for the first time. The rule was also revised on September 7, 1993 and September 14, 

1999. All previous changes to the SIP rule including the current submitted revisions are being

considered as part of this action. 

Rule 103 was updated when it was replaced with Rule 202 in 1977. The following is a list of 

changes made to Rule 103 as approved into the SIP compared with the current version of Rule

202 submitted for SIP approval. 

1. Existing Rule 103 exemptions were revised as follows:

• Exemption A is now listed in Rule 202 sections E.2.a and E.2.b and has been expanded 

from “vehicles as defined by the Vehicle Code of the State of California and air craft” 

(e.g., mobile sources) to also include locomotives and water craft used to transport 

passengers or freight. Section E.2.b also excludes from exemption equipment used for 

dredging of waterways or used in pile driving adjacent to or in waterways.

• Exemption B which pertains to equipment utilized exclusively in residential structures is 

now listed in Rule 202 Section E.3.a and has been changed from “equipment” exclusively 

used in connection with residential structures to the residential structure and any 

incinerator used exclusively in connection with such a structure.

• Exemption C - Comfort Air Conditioning is no longer included in the exemptions

(Section E) in Rule 202.

• Exemption D - Equipment used exclusively for space heating, other than boilers is no 

longer included in the list of exemptions (Section E) in Rule 202. 

• Exemption E - Equipment used for the purpose of preparing food for immediate human 

consumption is now included in Rule 202 Section E.6.a. This exemption has been 

expanded to more specifically describe food processing that is exempt, including mixers 

and blenders used in small bakeries (E.6.b), equipment to grind, blend, or package tea, 

cocoa, spices or roasted coffee (E.6.c), smokehouses with maximum horizontal inside 

cross-section less than 20 square feet (E.6.d) and barbeque equipment (E.6.e).

2. The following general provisions were added to the rule: 

• Section A specifies that an Authority to Construct or Permit to Operate shall not be 

required for any process, article, machine, equipment, or other contrivance listed in 

Section E, unless it is subject to New Source Performance Standards (NSPS), National
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Emission Standards for Hazardous Air Pollutants (NESHAPS), a source specific 

prohibitory rule or emits Toxic Air Contaminants, or if the APCO determines that the 

equipment may not operate in compliance with all APCD rules and regulations. 

• Section B exempts any process, article, machine, equipment, or other contrivance with 

uncontrolled emissions of affected pollutants less than or equal to two pounds in any 24 

hour period. 

• Section C requires a permit for equipment if it is part of a process that requires a permit. 

• Section D requires appropriate recordkeeping to verify and maintain any exemption.

• Section E lists equipment not required to have an Authority to Construct or Permit to 

Operate unless otherwise specified in sections A or B.

3. The following new exemptions were added to Section E in Rule 202. They are grouped 

together according to the justifications for providing the new exemptions. 

A. Equipment or processes that are not subject to a corresponding ICAPCD 

prohibitory rule. 

• E.1.a - Gas Turbines with max heat input rate of 3 million Btu per hour or less.

• E.1.c - Steam Generators, steam super heaters, water boilers, water heaters, steam 

cleaners, and closed indirect heat transfer systems which have a maximum input heat 

rating of 5 million Btu per hour or less and are exclusively fired with natural gas, 

liquefied petroleum gas or any combination thereof.

• E.5.a - Printing and related coating or laminating equipment not using more than 2 

gallons of graphic arts material per day.

• E.8.a - Unheated solvent dispensing containers with capacity of not more than 250 

gallons.

• E.8.c - Equipment used exclusively for storage of unheated organic material with an 

initial boiling point of 150°C or greater, or with a vapor pressure of 0.1 psia or less at 

21.1°C. 

• E.9.b - Unheated non-conveyorized cleaning equipment with open surface area of 1.0 

sq. meter or less and an internal volume of 92.5 gallons or less, using organic solvents 

with initial boiling point of 160°C or greater and less than 25 gallons of solvent loss 

per year.

• E.9.c - Surface coating equipment using a combined total of one gallon per day or 

less of coating material and solvent. 

• E.9.d - Surface coating using un-refillable aerosol spray cans.

B. Sources with insignificant emissions.

• E.4.a - Cooling Towers that have a circulation rate of less than 10,000 gallons per 

minute, which are not used for cooling of process water, water from barometric jets or 

water from barometric condensers.

• E.7.a - Plastic /Rubber Processing including foam manufacturing or application, 

fiberglass reinforced plastic fabrication, and plastics manufacturing using material 

contain Reactive Organic Compounds (ROCs), when aggregated emissions of ROCs 

from the equipment or process do not exceed 5 pounds in any one day.

• E.7.b - Presses used exclusively for extruding rubber products or plastic where no 

plasticizer or blowing agent is present or for pelletizing polystyrene foam scraps, 
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except equipment used to extrude or pelletize acrylics, polyvinyl chloride, 

polystyrene, or their copolymers. 

• E.7.c - Ovens used exclusively for curing, softening, or annealing of plastics. Does 

not apply to ovens used to cure fiberglass reinforced plastics.

• E8.d - Equipment used exclusively for unheated underground storage of 6,077 gallons 

or less of organic liquids with a vapor pressure of 1.5 psia or less at actual storage 

conditions and equipment used for transfer to and from such storage of organic 

liquids.

C. Equipment or operations which are not subject to overall NSR program 

requirements

• E.1.d - Portable Equipment registered under the Statewide Portable Equipment 

Registration Program.

• E.8.b – Mobile Transport Tanks or delivery tanks or cargo tanks on vehicles for 

delivery of VOCs except asphalt tankers used to transport and transfer hot asphalt for 

roofing applications. 

• E.9.a - Application equipment for architectural surface coatings.

• E.11. – Routine repairs or maintenance not involving any structural changes to any 

equipment for which a permit has been granted. 

D. Agricultural source exemptions as allowed by SB 700 and CARB definition of 

LCAF (CH&SC Section 86500).

• E.10.a - Stationary combustion agricultural sources with combined emissions of less 

than one half of any applicable emissions threshold for a major source.

• E10.b. - Any confined animal facility that maintains in any one day:

o Less than 1,000 milk producing cows, 

o less than 3,500 beef cattle, calves, heifers, or other cattle, 

o less than 100,000 turkeys, 

o less than 650,000 chickens other than laying hens, 

o less than 650,000 laying hens, 

o less than 3,000 swine, 

o less than 15,000 sheep, lambs, goats, 

o less than 2,500 horses, 

o less than 650,000 ducks, or

o less than 30,000 rabbits or other animals. 

Rule Evaluation 

EPA is primarily using the following three criteria to evaluate Rules 201 and 202.

1. Enforceability – CAA §110(a)(2)(A) requires that regulations submitted to EPA 

for SIP approval must be clear and legally enforceable. 

2. Anti-Backsliding - CAA §110(l) restricts certain SIP revisions that would relax 

existing SIP-approved requirements if they would interfere with the district’s 

ability to attain or maintain attainment of a NAAQS.
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3. New Source Review Program Requirements- 40 CFR part 51, Subpart I –Review 

of New Sources and Modifications.

The Clean Air Act requires states (Districts in California) to establish a program for 

preconstruction review of new or modified major stationary sources (New Source Review

– NSR) and to issue Authorities to Construct (ATC) and Permits to Operate (PTO) in 

nonattainment areas. 

Rules 201 – Permits Required, 202 – Exemptions, and 207 – New & Modified Stationary 

Source Review are the major components of ICAPCD’s NSR program. Rule 201 

identifies the types of permits required for construction and operation of sources as part 

of NSR as well as permits required by other District rules such as Rule 217 – Large 

Confined Animal Facilities (LCAF) Permits Required. Rule 202 identifies what sources 

are not required to obtain ATC or PTO. Rule 207 establishes the requirements for new 

and modified stationary sources to ensure that the operation of such sources does not 

interfere with the attainment or maintenance of Ambient Air Quality Standards. Under 

the federal NSR program, all major stationary sources (ones with potential emissions 

over specified thresholds) are required to obtain an ATC prior to construction. For minor 

sources (non-major), a District has flexibility to determine which types and sizes of 

sources are required to obtain a permit, as needed to ensure that all sources are subject to 

regulation as necessary to ensure attainment and maintenance of the NAAQS in 

accordance with their SIP approved attainment plan. This technical support document 

discusses only Rules 201 and 202 which we are evaluating for approval into the 

California SIP.

Rule 201 - Permits Required – The single revision to this rule is administrative and only 

serves to update the rule to identify new District permit requirements for Large Confined 

Animal Facilities found in Rules 217 and 420. This revision was necessary to comply 

with new state requirements for controlling emissions from agricultural sources as set out 

by SB700. This revision does not make any substantive changes that effect emissions 

and therefore does not merit further evaluation. 

Rule 202 – Exemptions (Rule 103) –Changes have been made to the original Rule 103, 

which are outlined above in the section titled “Purposes of Rule and Rule Amendments”.

These changes include not only administrative changes to the rule such as re-numbering

and updating the format, but also the addition of general provisions and a number of 

revisions and additions to the types of equipment exempted from permit requirements by 

the rule. The administrative changes to the rule provide additional clarity to the rule and 

do not affect the stringency of the District’s NSR program and therefore do not require 

further evaluation. The addition of new general provisions, and changes and additions to 

the exemptions found in Rule 103, which is the current SIP-approved rule, are evaluated 

below. 

1. Revision of Existing Rule 103 Exemptions

• The revisions to Exemption A, now listed in section E2.a and E.2.b, clarify what

types of mobile sources are exempt by including locomotives and water craft, 
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which are not considered stationary sources under the NSR program. It also 

strengthens the SIP by excluding from exemption equipment used for dredging of 

waterways or used in pile driving.

• The revisions to Exemption B, now listed in Section E.3.a, do not significantly 

change this exemption. The exemption now specifically identifies “any 

incinerator” in place of the more general term “equipment utilized” with a 

residential structure. 

• Exemptions C & D exempted equipment for comfort air conditioning and space 

heating and are no longer included in Rule 202. 

• The revisions to Exemption E, now in section E.6.a. through E.6.e. includes two 

changes. First, the wording has been changed slightly to clarify that it applies to 

equipment used in eating establishments or other retail establishments used to 

prepare food for human consumption. Second, the exemption has been revised to 

include several specific types of food processing operations (see Sections E.6.b to 

E.6.e) and to specify limitations on the size of some of the specified equipment. 

These new exemptions are more specific and more clearly identify the types of 

food processing equipment exempted from permit requirements. This improves

the clarity and enforceability of this provision. 

2. Addition of New General Provisions

ICAPCD added a number of new general provisions that were not found in Rule 103. 

These new general provisions are described above in the “Purposes of Rule and Rule 

Amendments” section of this document. 

• Sections A. and C. identify when an otherwise listed piece of equipment would 

not be exempt from permit requirements, for example when the equipment is 

subject to a NSPS or NESHAP. In general, these two sections place additional 

restrictions on the exemptions listed in Section E. Since this narrows the scope of 

the exemptions listed in Rule 103, this revision provides a strengthening of the 

SIP.

• Section B. exempts de minimus emission units with uncontrolled emissions of 

less than or equal to two pounds in any 24-hour period. EPA believes that this 

threshold can be considered de minimus in that any one source of this size would 

not affect the ability of the District to attain or maintain a NAAQS. 

• Section D. adds the requirement for recordkeeping to verify and maintain any 

exemption. This new requirement greatly strengthens enforceability of Rule 202

as required by CAA §110(a)(2)(A).

• Section E. states that unless otherwise specified in section A or B, an Authority to 

construct or Permit to Operate shall not be required for the equipment and 

processes listed in Sections E.1 to E.11. The specific exemptions provided in 

Section E are discussed elsewhere in this evaluation. The reference to section A 

simply reiterates the language of section A, in that the equipment listed in Section 

E is exempt from permit requirements, unless section A says otherwise. The 

reference to section B is different, since it provides an exemption for any 

equipment which emits less than 2 lbs in any 24-hour period. EPA reads this to 

mean that equipment listed in Section E is exempted from permit requirements, as 
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well as any equipment that meets the stated requirements listed in section B.

3. Addition of New Exemptions not included in Rule 103

The discussion below applies to the exemptions that were grouped together 

according to the justifications for providing the new exemption as described 

above in the “Purposes of Rule and Rule Amendments” section of this document.

A. Equipment or processes that are not subject to a corresponding ICAPCD 

prohibitory rule to control emissions. 

These types equipment or processes are typically exempted from prohibitory rule 

requirements due to output, size, low emissions or type of fuel used. These exemptions 

are provided in such rules so that sources for which it is not reasonable to control are not 

subject to control requirements. EPA believes the District’s choice to establish 

permitting thresholds in these rules that mirror prohibitory rule applicability or exemption 

thresholds, is reasonable since emission units under these thresholds are not subject to 

any emission control requirements for which a permit is needed to ensure compliance and 

no additional reductions will occur if a permit was otherwise required. 

B. Sources that have insignificant or de minimus emissions 

EPA believes that the sources listed in this group have very low levels of emissions due 

to type of process (e.g. mechanical or physical processes) that can be classified as

insignificant emissions and/or they are equipment or activities that have been identified 

by EPA as trivial in the “EPA White Paper for Streamlined Development of Part 70 

Permit Applications” (See Attachment #7). For example, cooling towers with a

circulation rate of less than 10,000 gallons per minute are estimated to have a maximum 

daily PM10 emission rate of less than 1.5 lbs per day and unheated underground organic 

liquid storage tanks of 6,077 gallons or less are estimated to have a maximum daily VOC 

emission rate of less than 1.0 lbs per day. In both cases, exempting these types of sources 

is consistent with the flexibility allowed states to exempt sources that are not likely to 

interfere with their ability to attain and maintain the NAAQS.

C. Equipment or operations which are not subject to NSR per 40 CFR part 51, 

Subpart I.

40 CFR part 51.165 defines the types of sources that are subject to NSR. NSR 

requirements apply to stationary sources only (buildings, structures, facilities) and do not 

apply to mobile sources (portable equipment) or other activities that have been 

specifically excluded such as routine repairs or maintenance. Emissions from 

architectural coatings are controlled when they are manufactured, by setting volatile 

organic compound standards for each type of coating. Accordingly, it is not necessary to 

regulate them as part of the NSR program. 

D. Agricultural source exemptions as allowed by SB 700.

Before SB700 was adopted in 2003, air districts in California were prohibited from

requiring permits for agricultural sources of air emissions. Because this prohibition 

existed in state law (CH&SC 42310(e)) most Districts did not provide specific 
9

exemptions for agricultural sources from the requirement to obtain an Authority to 

Construct or Permit to Operate in their local exemption rule. As part of this rule revision, 

the District is implementing state law by adding specific exemption thresholds for 

agricultural sources to Rule 202, which are as follows:

• Exemption E.10.a specifically exempts stationary combustion engines located at

agricultural sources, if the combined actual emissions are less than one half of any 

applicable major source emission threshold. For federal purposes, this would equate 

to a threshold of 50 tpy for VOCs and NOx and 35 tpy for PM10. While these

thresholds are higher than most emission based exemption thresholds contained in 

Rule 202, EPA notes these thresholds apply to the aggregate of engines at the 

agricultural stationary source and not individual emission units. 

• Exemption E.10.b provides an exemption for confined animal facilities that maintain 

less than the listed number of specified animals. These thresholds are based on the 

CH&SC definition developed by CARB as to what constitutes a Large Confined 

Animal Facility (LCAF). Only facilities which are not classified as a LCAF are 

exempt from permit requirements. CARB based the definition of LCAF on the 

number of animals housed daily at the facility and mainly focused their determination 

on air emission impacts from these sources in the San Joaquin Valley and South 

Coast (Los Angeles region) which are both extreme nonattainment areas for ozone. 

These thresholds take into consideration potential emissions from these sources and 

allow the most animals to be subject to permit requirements, while minimizing the 

number of facilities affected. Please see the attached CARB Staff Report for detailed 

information on the development of the definition of LCAF. By using emissions 

factors developed by San Joaquin Valley APCD for dairies (19.3 lbs/head-year) and 

beef feedlots (11 lbs/head-year), the VOC emissions resulting from 1000 milking 

cows is estimated to be 9.7 tpy and 19.7 tpy from beef feed lots (3500 head of cattle). 

There are two aspects of these revisions to examine: the effect on air quality and 

stringency compared to the existing SIP rule. Since the current SIP approved regulation 

providing exemptions from permit requirements (Rule 103) does not explicitly exempt 

agricultural sources, these revisions could be viewed as SIP relaxations. In reality, 

however, California state law prohibited Districts from issuing permits for to agricultural 

sources until enactment of SB 700 in September 2003 required air districts to adopt rules 

to regulate them. Therefore, until recently, the SIP has not achieved emission reductions 

from agricultural sources. With EPA’s approval of Rules 201 and 202, permits will be 

required to enforce the emission reductions for new and existing agricultural sources 

achieved through the implementation of Rule 217 and Rule 420. We also note that these

changes will bring many engines at agricultural sources into the permitting system for the 

first time. See Attachment # 4, ICAPCD Staff Report dated October, 10, 2006, for 

ICAPCD’s estimates for reduction of emissions from agricultural sources. Accordingly, 

EPA believes that overall these changes actually provide a strengthening of the SIP and 

are therefore approvable under 110(l) of the Act. 
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Rule Deficiencies

No deficiencies were found that would prevent EPA from recommending full approval of

ICAPCD Rules 201 and 202 into the SIP.

EPA Action

EPA has reviewed the submitted rules in accordance with the Rule Evaluation criteria described 

earlier in this document. Consistent with the requirements of 40 CFR Subpart I, all major 

stationary sources are required to obtain an ATC permit prior to construction. For minor 

sources, EPA believes that the emissions from types and sizes of equipment and operations 

exempted from NSR permit requirements are consistent with the flexibility afforded to states to 

regulate only those sources as necessary to assure attainment and maintenance of the NAAQS. 

While several new provisions have been added to Rule 202 that could be seen as a relaxation of 

the SIP because more sources are specifically exempted from Rule 207 permit requirements, in 

practice most of these sources have never been required to obtain a NSR ATC permit due to their 

small size or state law prohibitions. Because these rules will not worsen air quality, and will in 

fact require agricultural sources to obtain permits and be subject to control requirements for the 

first time, EPA believes that these revisions are a long overdue update to the SIP which will 

provide an overall strengthening of the SIP without interfering with the District’s ability to attain 

and maintain the NAAQS, and is therefore approvable under 110(l) of the CAA.

EPA recommends full approval of the following ICAPCD rules for incorporation into the 

California Applicable SIP, pursuant to section 110(k)(3) of the CAA as amended in 1990: 

• Rule 201 – Permits Required (amended on October 10, 2006, submitted on August 24, 

2007).

• Rule 202 – Exemptions (amended on October 10, 2006, submitted on August 24, 2007), 

replacing Rule 103, Exemptions, approved into the SIP on May 31, 1972 (37 FR 10842).

EPA Recommendations

The following revisions are not currently the basis for rule disapproval, but are recommended as 

improvements when this rule is amended.

• Rule 201: Correct typographical error in Section C – Rule 421 not Rule 421.7.

• Rule 201 and 202: A general provision should be added to identify where the terms 

applicable to the rule are defined, i.e. Rule 101, Definitions. For example, see new 

ICAPCD Rule 217 – Large Confined Animal Facilities (LCAF) Permits Required, 

Section B Definitions, which identifies where specific definitions can be found.

• Rule 202 Section E.10.a: for clarity and enforcement the term “stationary combustion 

agricultural sources” should be defined in Rule 202 or the term should be changed to use 

the term already defined in Rule 101 – Definitions, Agricultural Source. The Rule 101

definition of this term includes an exclusion for engines used to propel implements of 

husbandry, which is not clearly identified as part of the exemption for stationary 

combustion agricultural sources (E.10.a), since this term is not defined. 

Guidance and Policy Documents

Guidance and policy documents that we used to help evaluate rules and RACT requirements 

consistently include the following:
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1. Review of New Sources and Modifications, U.S. EPA, 40 CFR part 51, subpart I.

Requirements for Preparation, Adoption, and Submittal of Implementation Plans, U.S. 

EPA, 40 CFR part 51.

2. Addendum to the General Preamble for the Implementation of Title I of the Clean Air 

Act Amendments of 1990, 59 FR 41998 (August 16, 1994).

Attachments

1. ICAPCD Rule 201, Permits Required, and Rule 202, Exemptions, as submitted on

August 24, 2007.

2. ICAPCD SIP Approved Rule 201, approved January 3, 2007

3. ICAPCD SIP Approved Rule 103, Exemptions, approved May 31, 1972.

4. ICAPCD Staff Report (Rules 201, 202, 206, 217, 301, 307, and 420) dated October 10, 

2006.

5. California Senate Bill 700, dated September 22, 2003.

6. CARB Staff Report: Initial Statement of Reasons for Rulemaking, Public Hearing to 

Consider the Large Confined Animal Facility Definition, May 6, 2005. (Cover Only)

7. U.S. EPA, “EPA White Paper for Streamlined Development of Part 70 Permit 

Applications” dated July 10, 1995.