1 

Final Regulation Order 

AIRBORNE TOXIC CONTROL MEASURE 

FOR DIESEL PARTICULATE MATTER FROM 

PORTABLE ENGINES RATED AT 50 HORSEPOWER AND 

GREATER

Amend sections 93116.1, 93116.2, and 93116.3 Title 17, California Code of 

Regulations. 

(Note: The amendments identified below are shown in underline is used to indicate 

additions and strikeout is used to indicate deletions from the regulation text.)

§ 93116.1 Applicability. 

(a) Except as provided below, all portable engines having a maximum rated 

horsepower of 50 bhp and greater and fueled with diesel are subject to this 

regulation. 

(b) The following portable engines are not subject to this regulation: 

(1) Any engine used to propel mobile equipment or a motor vehicle of any 

kind; 

(2) Any portable engine using an alternative fuel; 

(3) Dual-fuel diesel pilot engines that use an alternative fuel or an alternative 

diesel fuel; 

(4) Tactical support equipment; 

(5) Portable diesel-fueled engines operated on either San Clemente or San 

Nicolas Island; 

(6) Engines preempted from State regulation under 42 USC §7543(e)(1); 

and 

(7) Portable diesel-fueled engines operated at airports that satisfiesy the 

following requirements: 

(A) the equipment is subject to the South Coast Ground Service 

Equipment Memorandum of Understanding (MOU); and 
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(B) the participating airlines have demonstrated to the satisfaction of the 

Executive Officer that the diesel PM reductions achieved by 

satisfying the requirements of the MOU are equivalent to the 

reductions achieved by this control measure. 

Authority cited: Sections 39600, 39601, 39650, 39658, 39659, 39666, 41752, 43013 

and 43018 Health and Safety Code. Reference: Sections 39650, 39666, 41752 Health 

and Safety Code. 

§ 93116.2 Definitions.

(a) For the purposes of these regulations, the following definitions apply:

(1) “Air Pollution Control Officer or APCO” Air Pollution Control Officer or APCO

means the air pollution control officer of a district, or his/her designee. 

(b)(2) “Alternative Fuel” Alternative Fuel means gasoline, natural gas, propane, 

liquid petroleum gas (LPG), hydrogen, ethanol, or methanol. 

(c)(3) “Alternative Diesel Fuel” Alternative Diesel Fuel means any fuel used in a 

compression ignition (CI) engine that is not, commonly or commercially 

known, sold or represented by the supplier as diesel fuel No. 1-D or No. 2-D, 

pursuant to the specifications in ASTM Standard Specification for Diesel Fuel 

Oils D975-81, or an alternative fuel, and does not require engine or fuel 

system modifications for the engine to operate, although minor modifications 

(e.g., recalibration of the engine fuel control) may enhance performance. An 

emission control strategy using a fuel additive will be treated as an alternative 

diesel fuel based strategy unless: 

(1)(A) the additive is supplied to the engine fuel by an on-board dosing 

mechanism, or 

(2)(B) the additive is directly mixed into the base fuel inside the fuel tank 

of the engine, or 

(3)(C) the additive and base fuel are not mixed until engine fueling 

commences, and no more additive plus base fuel combination is 

mixed than required for a single fueling of a single engine. 

(d)(4) “CARB Diesel Fuel” CARB Diesel Fuel means any diesel fuel that is 

commonly or commercially known, sold, or represented by the supplier as 

diesel fuel No. 1-D or No. 2-D, pursuant to the specification for Diesel Fuel 

Oils D975-81, and that meets the specifications defined in Title 13 CCR, 

sections 2281, 2282, and 2284. 
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(e)(5) “Certified Nonroad Engine” Certified Nonroad Engine refers to an engine 

meeting an applicable nonroad engine emission standard as set forth in Title 

13 of the California Code of Regulations or CFR 40 Part 89. 

(f)(6) “Diesel Fuel” Diesel Fuel means any fuel that is commonly or commercially 

known, sold, or represented by the supplier as diesel fuel, including any mixture of 

primarily liquid hydrocarbons—organic compounds consisting exclusively of the 

elements carbon and hydrogen—that is sold or represented as suitable for use in 

an engine. 

(g)(7) “Diesel-Fueled” Diesel-Fueled means fueled by diesel fuel, or CARB diesel 

fuel, in whole or part. 

(h)(8) “Diesel Particulate Matter (PM)” Diesel Particulate Matter (PM) means the 

particles found in the exhaust of diesel-fueled engines which may 

agglomerate and adsorb other species to form structures of complex physical 

and chemical properties. 

(i)(9)“District” District means a District as defined in Health and Safety Code 

section 39025. 

(j)(10) “Dual-fuel Diesel Pilot Engine” Dual-fuel Diesel Pilot Engine means a dualfueled engine that uses diesel fuel as a pilot ignition source at an annual average 

ratio of less than 5 parts diesel fuel to 100 parts total fuel on an energy equivalent 

basis. 

(k)(11) “Emergency” Emergency means providing electrical power or mechanical 

work during any of the following events and subject to the following conditions: 

(1) (A) the failure or loss of all or part of normal electrical power service or 

normal natural gas supply to the facility: 

(1) 1. which is caused by any reason other than the enforcement of a 

contractual obligation the owner or operator has with a third party or 

any other party; and 

(2) 2. which is demonstrated by the owner or operator to the district 

APCO’s satisfaction to have been beyond the reasonable control of 

the owner or operator; 

(2) (B) the failure of a facility’s internal power distribution system: 

(A)1. which is caused by any reason other than the enforcement of a 

contractual obligation the owner or operator has with a third party or 

any other party; and 
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(B)2. which is demonstrated by the owner or operator to the district 

APCO’s satisfaction to have been beyond the reasonable control of the 

owner or operator; 

(3) (C) the pumping of water or sewage to prevent or mitigate a flood or 

sewage overflow; 

(4) (D) the pumping of water for fire suppression or protection; 

(5) (E) the pumping of water to maintain pressure in the water distribution 

system for the following reasons: 

(A)1. pipe break; or 

(B)2. high demand on water supply system due to high use of water for 

fire suppression; 

(6) (F) the breakdown of electric-powered pumping equipment at sewage 

treatment facilities or water delivery facilities; 

(7) (G) the training of personnel in the use of portable equipment for 

emergency purposes. 

(l)(12)_“Emergency Event” Emergency Event refers to a situation arising from a 

sudden and reasonably unforeseen natural disaster such as an earthquake, flood, 

fire, or other acts of God, or other unforeseen event that requires the use of 

portable engines to help alleviate the threat to public health and safety. 

(m)(13) (“Engine” Engine means any piston-driven internal combustion engine. 

(n)(14) “Engines Used Exclusively in Emergency Applications” Engines Used 

Exclusively in Emergency Applications refer to engines that are used only 

during an emergency or emergency event, and includes appropriate 

maintenance and testing.

(o)(15) “Executive Officer” Executive Officer means the Executive Officer of the 

California Air Resources Board (CARB) or his/her designee. 

(p)(16) “Fleet” Fleet refers to a portable engine or group of portable engines that 

are owned and managed by an individual operational entity, such as a 

business, business unit within a corporation, or individual city or state 

department under the control of a Responsible Official. Engines that are 
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owned by different business entities that are under the common control of 

only one Responsible Official shall be treated as a single fleet. 

(q)(17) “Fuel Additive” Fuel Additive means any substance designed to be added 

to fuel or fuel systems or other engine-related systems such that it is present 

in-cylinder during combustion and has any of the following effects: decreased 

emissions, improved fuel economy, increased performance of the engine; or 

assists diesel emission control strategies in decreasing emissions, or 

improving fuel economy or increasing performance of the engine. Fuel 

additives used in conjunction with diesel fuel may be treated as an alternative 

diesel fuel. 

(r)(18) “In-Use Engines” In-Use Engines refers to portable diesel-fueled engines 

operating under valid permits or registrations as of December 31, 2005. 

(s)(19) “Level-3 Verified Technology” Level-3 Verified Technology means a 

technology that has satisfied the requirements of the “Verification Procedure 

for In-Use Strategies to Control Emissions from Diesel Engines” in Title 13, 

California Code of Regulations, commencing with section 2700, and has 

demonstrated an reduction in diesel particulate matter of 85% or greater. 

(t)(20) “Location” Location means any single site at a building, structure, facility, 

or installation. 

(u)(21) “Low-Use Engines” Low-Use Engines refers to portable diesel-fueled 

engines that operate 80 hours or less in a calendar year. 

(v)(22) “Maximum Rated Horsepower (brake horsepower (bhp))” Maximum Rated 

Horsepower (brake horsepower (bhp)) is the maximum brake horsepower 

rating specified by the portable engine manufacturer and listed on the 

nameplate of the portable engine. 

(w)(23) “Nonroad Engine” Nonroad Engine means: 

(1)(A) Except as discussed in paragraph (2) of this definition, a nonroad 

engine is any engine: 

(A)1. in or on a piece of equipment that is self-propelled or serves a dual 

purpose by both propelling itself and performing another function 

(such as garden tractors, off-highway mobile cranes and 

bulldozers); or 

(B)2. in or on a piece of equipment that is intended to be propelled while 

performing its function (such as lawnmowers and string trimmers); 

or 
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(C)3. that, by itself or in or on a piece of equipment, is portable or 

transportable, meaning designed to be and capable of being 

carried or moved from one location to another. Indicia of 

transportability include, but are not limited to, wheels, skids, 

carrying handles, dolly, trailer, or platform. 

(2)(B) An engine is not a nonroad engine if: 

(A)1. the engine is used to propel a motor vehicle or a vehicle used 

solely for competition, or is subject to standards promulgated under 

section 202 of the federal Clean Air Act; or 

(B)2. the engine is regulated by a federal New Source Performance 

Standard promulgated under section 111 of the federal Clean Air 

Act; or 

(C)3. the engine otherwise included in paragraph (1)(C) of this definition 

remains or will remain at a location for more than 12 consecutive 

months or a shorter period of time for an engine located at a 

seasonal source. Any engine(s) that replace(s) an engine at a 

location and that is intended to perform the same or similar function 

as the engine replaced will be included in calculating the 

consecutive time period. An engine located at a seasonal source is 

an engine that remains at a seasonal source during the full annual 

operating period of the seasonal source. A seasonal source is a 

stationary source that remains in a single location on a permanent 

basis (at least two years) and that operates at that single location 

approximately three (or more) months each year. 

(x)(24) “Off-Road Engine” Off-Road Engine means the same as nonroad engine. 

(y)(25) “Outer Continental Shelf (OCS)” Outer Continental Shelf (OCS)shall have 

the meaning provided by section 2 of the Outer Continental Shelf Lands Act 

(43 USC Section 1331 et seq.).

(z)(26) “Participating Airlines” Participating Airlines means the collective group of 

Individual Participating Airlines under the MOU, which currently is as follows: 

ABX Air, Inc. (formerly Airborne Express), Alaska Airlines, America West 

Airlines, American Airlines, ATA Airlines (formerly American Trans Air), 

Continental Airlines, Delta Air Lines, Astar Air Cargo (formerly DHL Airways), 

Federal Express, Hawaiian Airlines, Jet Blue Airways Corp., Midwest Airlines 

(formerly Midwest Express Airlines), Northwest Airlines, Southwest Airlines, 

United Airlines, United Parcel Service, and US Airways. Participating Airlines 

does not mean the Air Transportation Association of America, Inc.
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(aa)(27) “Permit” Permit refers to a certificate issued by the Air Pollution Control 

Officer acknowledging expected compliance with the applicable requirements 

of the district’s rules and regulations. 

(bb)(28) “Portable” Portable means designed and capable of being carried or 

moved from one location to another. Indicia of portability include, but are not 

limited to, wheels, skids, carrying handles, dolly, trailer, or platform. For the 

purposes of this regulation, dredge engines on a boat or barge are 

considered portable. The engine is not portable if: 

(1)(A) the engine or its replacement is attached to a foundation, or if not 

so attached, will reside at the same location for more than 12 

consecutive months. The period during which the engine is 

maintained at a storage facility shall be excluded from the 

residency time determination. Any engine, such as a back-up or 

stand-by engine, that replace engine(s) at a location, and is 

intended to perform the same or similar function as the engine(s) 

being replaced, will be included in calculating the consecutive time 

period. In that case, the cumulative time of all engine(s), including 

the time between the removal of the original engine(s) and 

installation of the replacement engine(s), will be counted toward the 

consecutive time period; or 

(2)(B) the engine remains or will reside at a location for less than 12 

consecutive months if the engine is located at a seasonal source 

and operates during the full annual operating period of the seasonal 

source, where a seasonal source is a stationary source that 

remains in a single location on a permanent basis (at least two 

years) and that operates at that single location at least three 

months each year; or 

(3)(C) the engine is moved from one location to another in an attempt to 

circumvent the portable residence time requirements. 

(cc)(29) “Project” Project means the use of one or more registered or permitted 

portable engines or equipment units operated under the same or common 

ownership or control to perform a single activity. 

(dd)(30) “Registration” Registration refers to either: 

(1)(A) a certificate issued by the Executive Officer acknowledging 

expected compliance with the applicable requirements of the 

Statewide Portable Equipment Registration Program; or 

(2)(B) a certificate issued by the Air Pollution Control Officer 

acknowledging expected compliance with the applicable 
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requirements of the district's Portable Equipment Registration 

Program. 

(ee)(31) “Responsible Official” Responsible Official refers to an individual 

employed by the company or public agency with the authority to certify that 

the portable engines under his/her jurisdiction compliesy with applicable 

requirements of this regulation. A company or public agency may have more 

than one Responsible Official. A contracted designee cannot certify 

compliance in lieu of the Responsible Official.

(ff)(32) “Selective Catalytic Reduction (SCR) System” Selective Catalytic 

Reduction (SCR) System refers to an air pollution emissions control system 

that reduces oxides of nitrogen (NOx) emissions through the catalytic 

reduction of NOx by injecting nitrogen-containing compounds into the exhaust 

stream, such as ammonia or urea. 

(gg)(33) “Stationary Source” Stationary Source means any building, structure, 

facility or installation that emits any air contaminant directly or as a fugitive 

emission. Building, structure, facility, or installation includes all pollutant 

emitting activities which: 

(1)(A) are under the same ownership or operation, or which are owned or 

operated by entities which are under common control; and 

(2)(B) 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 industrial process, 

manufacturing process, or connected process involving a common 

raw material; and 

(3)(C) are located on one or more contiguous or adjacent properties. 

[Note: For the purposes of this regulation a stationary source and 

nonroad engine are mutually exclusive.] 

(34) “Stock Engine” means a certified diesel-fueled engine that has never been 

placed in service and is part of a supply of engines offered for sale, rent, or 

lease by a person or company who offers for sale, rent, or lease engines and 

related equipment for profit.

(hh35)“Storage” Storage means a warehouse, enclosed yard, or other area 

established for the primary purpose of maintaining portable engines when not 

in operation. 

(ii36)“Tactical Support Equipment (TSE)” Tactical Support Equipment (TSE)

means equipment using a portable engine, including turbines, that meets 
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military specifications, owned by the U.S. Department of Defense and/or the 

U.S. military services or its allies, and used in combat, combat support, 

combat service support, tactical or relief operations, or training for such 

operations. Examples include, but are not limited to, engines associated with 

portable generators, aircraft start carts, heaters and lighting carts. 

(jj37) “Tier 4 Emission Standards” Tier 4 Emission Standards refers to the final 

emission standards adopted by the U.S. EPA for newly manufactured 

nonroad engines. 

(kk38) “Transportable” Transportable means the same as portable. 

(ll39) “Verified Emission Control Strategy” Verified Emission Control Strategy refers 

to an emission control strategy, designed primarily for the reduction of diesel 

PM emissions which has been verified pursuant to the “Verification Procedure 

for In-Use Strategies to Control Emissions from Diesel Engines” in Title 13, 

California Code of Regulations, commencing with section 2700, and 

incorporated by reference. 

(mm40) “U.S. EPA” U.S. EPA refers to the United States Environmental Protection 

Agency. 

Authority cited: Sections 39600, 39601, 39650, 39658, 39659, 39666, 41752, 43013 

and 43018 Health and Safety Code. Reference: Sections 39650, 39666, 41752 Health 

and Safety Code. 

§ 93116.3 Requirements.

(a) Diesel-fueled portable engines shall only use one of the following fuels: 

(1) CARB diesel fuel; or 

(2) alternative diesel fuel that has been verified through the Verification 

Procedure for In-Use Strategies to Control Emissions from Diesel 

Engines; or 

(3) CARB diesel fuel utilizing fuel additives that have been verified through 

the Verification Procedure for In-Use Strategies to Control Emissions 

from Diesel Engines. 

[Note that credit for diesel PM reductions for diesel fuel or CARB diesel 

fuel blends that use an alternative diesel fuel such as biodiesel, FischerTropsch fuels, or emulsions of water in diesel fuel is available only for 

fuel blends that been verified through the Verification Procedure for InUse Strategies to Control Emissions from Diesel Engines. The credit 
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granted is based upon the verified level approved by the Executive 

Officer within the Executive Order for the fuel blend.] 

(b) Diesel PM Standards 

(1) Requirements for in-use portable diesel-fueled engines 

(A) Except as provided in sections 93116.3(b)(1)(B) and 

93116.3 (b)(4), starting January 1, 2010, all portable diesel-fueled 

engines shall be certified to meet a federal or California standard 

for newly manufactured nonroad engines pursuant to 40 CFR Part 

89 or Title 13 of the California Code of Regulations (that is, certified 

to Tier 1, 2 or 3 nonroad engine standards).1

(B) In lieu of complying with (b)(1)(A), owners of portable diesel-fueled 

engines used exclusively in emergency applications or portable 

diesel-fueled engines that qualify as low-use engines may commit 

to replacing these engines with Tier 4 engines, subject to the 

requirements below: 

1. the Responsible Official shall submit written notification 

identifying the specific portable diesel-fueled engines to be 

replaced with portable diesel-fueled engines certified to the 

Tier 4 emission standards; and 

2. for each class and category of nonroad engine, replace each 

portable diesel-fueled engine so identified within two years of 

the first engine being offered for sale that satisfies the Tier 4 

emission standards. 

(2) Portable diesel-fueled engines that have not been permitted or 

registered prior to January 1, 2006, are subject to the following 

requirements: 

(A) except as provided specified in 93116.3(b)(5), 93116.3(b)(6), and

93116.3(b)(7), and 93116.3(b)(8) and except as allowed under 

flexibility provisions for equipment and vehicle manufacturers and 

post-manufacture marinizers pursuant to 40 CFR Part 89 or Title 13 

of the California Code of Regulations, the portable diesel-fueled 

 

1

 Tier 1, 2, 3, and 4 refer to nonroad engine emission standards promulgated by ARB and U.S. EPA for 

newly manufactured engines pursuant to 40 CFR Part 89 or Title 13 of the California Code of Regulation. 

Each successive Tier represents more stringent emission standards and the requirements are phased-in 

over time with the Tier 1 engine standards becoming effective for some engines manufactured in 1996 

and becoming effective for all engines by 2000. Tier 2 engine standards are phased in for engines 

manufactured beginning in 2001 and becomes effective for all engines by 2006. Similarly, Tier 3 engines 

are phased in for engines manufactured beginning in 2006, and Tier 4 engines are phased in for engines

manufactured beginning in 2011. 
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engine shall meet the most stringent of the federal or California 

emission standard for nonroad engines; or 

(B) upon approval by the air pollution control officer, a diesel-fueled 

portable engine not certified to an emission standard pursuant to 40 

CFR Part 89 or Title 13 of the California Code of Regulations used 

exclusively in emergency applications or qualifying as a low-use 

engine designation may only be permitted or registered by a 

district. Any engine used exclusively in emergency applications or 

qualifying as a low-use engine designation is subject to the 

requirements of section 93116.3(b)(3). 

(3) Except as provided in section 93116.3(b)(1)(B), portable diesel-fueled 

engines used exclusively in emergency applications or qualifying as lowuse engines shall satisfy one of the following requirements by January 1, 

2020: 

(A) the portable diesel-fueled engine is certified to Tier 4 

emission standards for newly manufactured nonroad 

engines; or 

(B) the portable diesel-fueled engine is equipped with a properly 

functioning level-3 verified technology; or 

(C) the portable diesel-fueled engine is equipped with a 

combination of verified emission control strategies that have 

been verified together to achieve at least 85% reduction in 

diesel PM emissions. 

(4) Lattice boom cranes 

(A) A portable diesel-fueled engine used in a lattice boom crane shall 

be exempt from the requirements of section 93116.3(b)(1)(A) if the 

Responsible Official has demonstrated to the satisfaction of the 

Executive Officer or the APCO that the portable diesel-fueled 

engine in the lattice boom crane cannot be replaced with a portable 

diesel-fueled engine that is certified to meet a federal or California 

standard for newly manufactured nonroad engines pursuant to 40 

CFR Part 89 or Title 13 of the California Code of Regulations (that 

is, certified to Tier 1, 2 or 3 nonroad engine standards). 

(B) Portable diesel-fueled engines exempt from the requirements of 

section 93116.3(b)(1)(A) pursuant to section 93116.3(b)(4)(A) shall 

satisfy one of the following requirements by January 1, 2020: 

1. the portable diesel-fueled engine is certified to Tier 4 

emission standards for newly manufactured nonroad 

engines; or 
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2. the portable diesel-fueled engine is equipped with a properly 

functioning level-3 verified technology; or 

3. the portable diesel-fueled engine is equipped with a 

combination of verified emission control strategies that have 

been verified together to achieve at least 85% reduction in 

diesel PM emissions. 

(5) Engines operated in California between March 41, 2004 and October 1, 

2006 may be permitted or registered by a district or registered in the 

Statewide Portable Equipment Registration Program until 12/31/09 if 

they meet an emission standard pursuant to 40 CFR Part 89 or Title 13 

of the California Code of Regulations. 

(6) Upon approval by the air pollution control officer, a district may permit or 

register engines operated in California between March 1, 2004 and 

October 1, 2006 that are not certified to an emission standard pursuant 

to 40 CFR Part 89 or Title 13 of the California Code of Regulations. 

(7) An engine owner, operator, dealer, or distributor may permit or register 

an stock engine not meeting the most stringent emission standard 

providing the following are met: 

(A) Verifiable information is provided to the satisfaction of the Executive 

Officer or District at the time of taking possession, the engine met 

the most stringent emission standard in effect prior to the change 

for that horsepower range; and 

(B) The application for permit or registration of the engine is submitted 

within six months of the effective date of the change in emission 

standards. 

(8) If the Executive Officer or District finds, based on verifiable information, 

that an owner had ordered or purchased, within six months prior to the 

date of an emissions standard changes for that horsepower range, but 

has not taken possession of, an engine meeting the most stringent 

emissions standard in effect at the time of order or purchase, the owner

or operator will have up to six months after the date the new emissions 

standard for that engine became effective to submit an application to 

permit or register the engine.

(c) Fleet Requirements 

(1) Each fleet is subject to and shall comply with the following weighted PM 

emission fleet averages expressed as grams per brake horsepower-hour 

(g/bhp-hr) by the listed compliance dates: 
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Fleet Standard 

Compliance Date 

Engines <175 hp 

(g/bhp-hr) 

Engines >175 to 

749 hp 

(g/bhp-hr) 

Engines >750 hp 

(g/bhp-hr) 

1/1/13 0.3 0.15 0.25 

1/1/17 0.18 0.08 0.08 

1/1/20 0.04 0.02 0.02 

(2) For the purposes of this regulation, the portable diesel-fueled engines 

affected by the fleet provisions of this regulation include all portable 

diesel-fueled engines operated in California, including portable dieselfueled engines registered with the Statewide Portable Equipment 

Registration Program or permitted by or registered with a district. 

(3) The following portable diesel-fueled engines shall be excluded from the 

fleet requirements: 

(A) portable diesel-fueled engines operated exclusively outside of 

California or operated only within the OCS. 

(B) portable diesel-fueled engines used exclusively in emergency 

applications. 

(C) portable diesel-fueled engines that qualify as low-use engines. 

(D) portable diesel-fueled engines used in a lattice boom crane. 

(4) Portable diesel-fueled engines that qualify as low-use engines and 

subsequently exceed the allowed hours of operation in a calendar year, 

or portable diesel-fueled engines that are identified to be used 

exclusively in emergency applications but subsequently are used in nonemergency applications, become immediately subject to the 

requirements of section 93116.3(c) in the year such exceedence or use 

occurs. For low-use engines, the hours of operation used for an 

emergency event shall not be counted toward the allowed hours of 

operation. 

(5) Portable alternative-fueled engines may be included in a fleet if the 

engine satisfies the requirements in section 93116.3(d)(2)(B). 

(6) Portable diesel-fueled portable engines equipped with SCR systems. 

(A) The diesel PM fleet emission standards in section 93116.3(c)(1) do 

not apply to: 
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1. portable diesel-fueled engines equipped with properly 

operating SCR systems as of January 1, 2004; and 

2. with the approval of the Executive Officer, portable dieselfueled engines equipped with properly operating SCR systems 

after January 1, 2004. 

(B) At the request of the Responsible Official, portable diesel-fueled 

engine(s) equipped with a SCR system(s) may be included in the 

company's fleet for the purpose of complying with an applicable 

fleet emission standard. Once the engine(s) is included in a fleet, 

compliance with applicable fleet emission standards shall always 

include these diesel-fueled portable engine(s). 

(C) For all diesel-fueled portable engines equipped with SCR systems, 

the following information shall be submitted to the Executive Officer 

to demonstrate that the SCR system is operating properly: 

1. Tests results for NOx, PM, and ammonia slip 

a. the following tests methods shall be used to demonstrate 

compliance: 

i. NOX shall be measured with CARB test method 

100 dated July 1997, or equivalent districtapproved test method; and 

ii. diesel PM shall be measured with CARB test 

method 5 dated July 1997 or equivalent districtapproved test method. For the purposes of this 

requirement, only the probe catch and filter catch 

("front half") is used to determine the emission 

rate, g/bhp-hr, and shall not include PM captured 

in the impinger catch or solvent extract; and 

iii. ammonia slip shall be measured with Bay Area Air 

Quality Management District Source Test 

Procedure ST-1B, Ammonia Integrated Sampling, 

dated January 1982, or other equivalent district 

approved test method. 

b. the duration of the emission test shall be sufficient to 

document the typical operation of the portable dieselfueled engine(s); and 
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c. testing shall be performed at the frequency required by 

the permit or registration. In no event shall the time 

between emission tests exceed three years. 

(7) Beginning on January 1, 2013, the weighted average PM emission rate 

for the fleet cannot exceed the fleet standard that is in effect. Changes 

in the fleet, including portable engine additions and deletions, shall not 

result in noncompliance with this standard. 

(d) Fleet Average Calculations 

(1) General Provisions 

(A) The average PM emission factor for the fleet is determined by the 

following formula: 

∑ Summation for each portable engine in the fleet (bhp x emission factor)

 ∑Summation for each portable engine in the fleet (bhp) 

where: 

bhp = maximum rated horsepower. 

emission = diesel PM emission rate, as determined below: 

factor 

(B) The following diesel PM emission rates shall be used with the 

above formula to determine the weighted average fleet emission 

rate: 

1. for portable diesel-fueled engines certified to a nonroad 

engine standard, the results of emission measurements 

submitted to either the U.S. EPA or CARB for the purposes 

of satisfying the appropriate emission standard; or

2. results from emission measurements from a verified 

emission control strategy may be used in conjunction with 

engine emission information; or 

3. for portable diesel-fueled engine(s) equipped with SCR 

system(s), results from valid emission tests. 

(2) The following incentives may be used to revise the fleet average, as 

outlined below: 
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(A) Where equipment uses grid power for more than 200 hours in lieu 

of operating a portable diesel-fueled engine for a given project, 

the time period grid power is used may be used to reduce each 

affected engine's emission factor. The emission factor for each 

affected portable engine will be reduced proportionally by the 

percentage of time the equipment uses grid power. To receive 

credit for grid power in the fleet calculation, the recordkeeping and 

reporting requirements in section 93116.4(c)(3) shall be satisfied. 

(B) Alternative-fueled portable engines 

1. Alternative-fueled portable engines operating 100 or more 

hours may be included toward determining compliance with 

the applicable fleet emission standards. A diesel PM 

emission rate of zero shall be used in the fleet calculations 

for these engines. 

2. Alternative-fueled portable engines operating 100 or more 

hours per calendar year and added to a fleet prior to January 

1, 2009, may be counted twice in the company's fleet 

average determination toward compliance with the 2013 and 

2017 fleet emission standards. The alternative-fueled 

engine shall be certified to meet a federal or California 

standard for newly manufactured nonroad engines pursuant 

to 40 CFR Part 89 or Title 13 of the California Code of 

Regulations. 

(B) Portable diesel-fueled engines certified to Tier 4 nonroad engine 

standards that are added to a fleet prior to January 1, 2015, may 

be counted twice in the company's fleet average determination 

toward compliance with the 2013 and 2017 fleet emission 

standards. 

Authority cited: Sections 39600, 39601, 39650, 39658, 39659, 39666, 41752, 43013 

and 43018 Health and Safety Code. Reference: Sections 39650, 39666, 41752, Health 

and Safety Code. 
17

§ 93116.3.1 Compliance Flexibility for Diesel PM Standards.

If the Executive Officer or District finds, based on verifiable information from the 

engine manufacturer, distributor, or dealer, that current model year engines 

meeting the current emission standards are not available or not available in 

sufficient numbers or in a sufficient range of makes, models, and horsepower 

ratings, then the Executive Officer or the District may allow the sale, purchase, or 

installation of a new stock engine meeting the emission standards from the 

previous model year to meet the emission standards in sections 93116.3(b). 

Authority cited: Sections 39600, 39601, 39650, 39658, 39659, 39666, 41752, 43013 

and 43018 Health and Safety Code. Reference: Sections 39650, 39666, 41752, Health 

and Safety Code.