(Adopted: 12/20/93)

Rule 1160

Internal Combustion Engines

(A) General

(1) Purpose: The purpose of this rule is to establish

limits for emissions associated with emergency,

portable, standby, or stationary internal combustion

(IC) engines.

(2) Applicability: This rule is applicable to any

stationary internal combustion engine rated at 1000 or

more brake horsepower (bhp), when located within the

Federal Ozone Non-attainment Area and within the

District boundaries.

(B) Definitions

For the purposes of this rule, the following definitions

shall apply:

(1) "Aggregate Emissions": A facility-wide sum of actual

emissions, on an emissions category specific basis,

from engines subject to this rule operated at a single

facility. Such "aggregating" of emissions will include

all regulated emissions categories subject to this


(2) "Baseline Emission Rate": Emissions under normal

operating conditions, prior to control, determined by

an emissions compliance test conducted in accordance

with the requirements specified in Section (F). The

baseline emissions shall be adjusted to reflect any

operational limit or control equipment installed prior

to January 1, 1991.

(3) "Diesel-Cycle Engine": A two or four stroke

compression ignition engine that is operated on any

liquid or gaseous fuel, and with an exhaust stream

oxygen concentration of four percent by volume or


(4) "Emergency IC Engines": For purposes of this rule,

internal combustion engines used in driving electric

power generators during periods of loss of commercial

power at facilities normally serviced with commercial

power. These units are normally operated during periods

of compliance and operational preparedness testing (1

hr/wk) and during periods of actual power loss.

(5) "Emissions Compliance Test": An emissions compliance

test conducted in accordance with a District approved

test protocol pursuant to the District's Compliance

Test Procedural Manual.

(6) "Engine Rating": The output of an engine as determined

by the engine manufacturer and listed on the nameplate

of the unit, regardless of any derating.

(7) "Federal Ozone Non-attainment Area" That portion of

San Bernardino County that lies south and/or west of

the lines which begin at: (a) the San Bernardino -

Riverside County boundary, running north along the

range line common to Range 3 East and Range 2 East;

(b) then west along the township line common to

Township 2 North and Township 3 North; (c) then north

along the San Bernardino - Los Angeles County Boundary;

(d) then east along ;latitude 35 degrees, 10 minutes

north; (e) then south along longitude 115 degrees, 45

minutes west (see Map 1).

(8) "Lean-burn Engine": A spark-ignited engine that is

operated with any liquid or gaseous fuel and with an

exhaust stream oxygen concentration of four percent by

volume, or greater.

(9) "Portable Engines": Engines which are operated at one

site, but not permanently affixed to only one location.

Portable equipment includes I.C. engines which are

transportable and may be mounted on mobile sources,

trailers, skids, or other platforms.

(10) "Reactive Organic Compounds (ROC)" - Are any volatile

compounds containing at least one atom of carbon,

except for the following exempt compounds:


carbon monoxide,

carbon dioxide,

carbonic acid,

metallic carbides or carbonates,

ammonium carbonate,


methylene chloride,

trifluoromethane (FC-23),

trichlorotrifluoroethane (CFC-113),

dichlorodifluoromethane (CFC-12),

trichlorofluoromethane (CFC-11),

chlorodifluoromethane (CFC-22),

dichlorotetrafluoroethane (CFC-114),

chloropentafluoroethane (CFC-115)

pentafluoroethane (HFC-125),

tetrafluoroethane (HFC-134 and 134a),

dichlorofluoroethane (HCFC-141b),

chlorodifluoroethane (HCFC-142b),

trifluoroethane (HFC-143a),

difluoroethane (HFC-152a),

and the following four classes of perfluorocarbon (PFC)


(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;


(d) Saturated perfluorocarbons containing sulfur with

sulfur bonds only to carbon and fluorine.

(11) "Rich-burn Engine": A spark ignited engine that is

operated with any liquid or gaseous fuel, and with a

exhaust stream oxygen concentration of less than four

percent by volume.

(12) "Standby Engine": Any internal combustion engine which

operates as a mechanical or electrical power source as

a temporary replacement for a primary power source

during periods of fuel/energy shortage or while the

primary power source is undergoing maintenance or


(13) "Stationary Internal Combustion Engine": Any spark or

compression ignited reciprocating internal combustion

engine that is attached to a foundation at a location,

or is portable and operated at a location for more than

90 days in any consecutive twelve month period,

excluding engines used for self propulsion of a


(C) Requirements

(1) Compliance Schedule

(a) All internal combustion engines subject to this

rule shall achieve an overall 15 percent reduction

in their baseline emissions rate by January 1,


(b) All internal combustion engines subject to this

rule shall meet and be in full compliance with the

emissions requirements of subsections (C)(2) or

(C)(3) by January 1, 1998.

(2) Concentration Standards

Unless opting for the alternative NOx emissions

compliance strategy, on and after January 1, 1998,

engines subject to this rule shall not exceed the

following concentration standards:

(a) Rich-burn Engines:

Oxides of Nitrogen (NOx) 50 ppmv*

Reactive Organic Compounds (ROC) 250 ppmv*

Carbon Monoxide (CO) 4500 ppmv*

(b) Lean-burn Engines:

Oxides of Nitrogen (NOx) 140 ppmv*

Reactive Organic Compounds (ROC) 750 ppmv*

Carbon Monoxide (CO) 4500 ppmv*

(c) Diesel-cycle Engines:

Oxides of Nitrogen (NOx) 700 ppmv*

Reactive Organic Compounds (ROC) 750 ppmv*

Carbon Monoxide (CO) 4500 ppmv*

* All ppmv limitations shall be referenced at 15

percent volume stack gas oxygen measured on a dry

basis and averaged over 15 consecutive minutes.

(3) Alternative Compliance Strategy - NOx Emissions Only

The ROC and CO standards continue to apply when this

alternative NOx emissions compliance strategy is

selected by the permittee in consultation with the

District. For NOx emissions only, the alternative

strategy is a specified minimum percent reduction in

emissions of NOx from the baseline emissions rate. On

and after January 1, 1998, engines subject to this

rule, opting for the alternative compliance strategy,

shall achieve at least the following minimum


(a) Rich-burn Engines

not less than a 90 % reduction of NOx emissions

from the baseline rate

(b) Lean-burn Engines

not less than an 80 % reduction of NOx emissions

from the baseline rate

(c) Diesel-cycle Engines

not less than a 30 % reduction of NOx emissions

from the baseline rate

Following the baseline emission rate determination for

each engine subject to this rule, the choice of which

emission compliance standard shall apply, shall be made

on a case-by-case basis by the District in consultation

with the permittee. When such a determination is made,

the Authority To Construct/Permit To Operate (ATC/PTO)

shall thereafter contain specific enforceable operating

conditions which will ensure compliance with the

selected standard/limit.

The percent reduction as measured across the control

device or relative to the baseline emission rate of

each permit unit shall be determined on an emission

rate basis. A permittee may petition the District to

be allowed to "aggregate" the engine emissions

facility-wide by submitting an Emission Control &

Mitigation Plan. The District may approve the

facility's Emission Control & Mitigation Plan, pursuant

to subsection (C)(5), on a case-by-case basis.

(4) Demonstrated Engine Efficiency Alternative

For engines subject to this rule with a demonstrated

efficiency greater than 30%, the following procedure

may be used to determine the alternate allowable

emissions limit. Each emission limit expressed in

subsection (C)(2) may be multiplied by the engine

efficiency, (E), divided by the reference efficiency of

30 percent. Engine efficiency (E) shall be determined

using one of the following two methods, whichever is


(a) (3413 BTU/kW-Hr)(100)

E = -------------------------------------------

Actual Heat Rate at HHV of fuel (BTU/kW-Hr)

where the demonstrated percent efficiency (E)

applies to the engine only, without consideration

of any downstream energy recovery, is averaged

over 15 consecutive minutes and measured within 30

days of the first emissions compliance test. The

actual heat rate in Btu/kW-hr, which can be

converted to Btu/hp-hr by dividing by 1.34

according to the following formula, shall be

measured at peak load for each applicable engine.

(BTU/kwhr) = (BTU/bhp-hr)



(b) E= (Mfg Rated Efficiency [Continuous] at LHV)(LHV)



Engine efficiency (E) shall not be less than 30

percent. An engine with less than a 30 percent

efficiency, shall be assigned an efficiency of 30

percent for the purpose of this rule.

(5) Emission Control & Mitigation Plan

The permittee may elect to petition the District for

the purpose of aggregating internal combustion engine

emissions in order to comply with emissions reduction

limitations under the percent reduction option in

subsection (C)(3). The operator of a facility subject

to the provisions of subsections (C)(1), (C)(2) or

(C)(4) of this rule shall, when selecting the emissions

aggregating approach to compliance, submit an Emission

Control and Mitigation Plan for the facility to the

District. The facility's Emission Control & Mitigation

Plan shall be submitted to the District not later than

January 1, 1995.

All affected internal combustion engines within the

facility shall be addressed within the Plan and each

engine shall be identified as to which option for

emissions compliance, i.e. the per engine ppmv limit,

the per engine adjusted ppmv limit, or the per engine %

reduction limit. The specific designation shall be

recorded onto the ATC/PTO along with any specific

operating limits or emissions limits pertaining to the

specific engine, as enforceable permit conditions.

The Plan shall be approved by the Air Pollution Control

Officer in writing. For new engines and modifications

to existing engines, the plan shall be submitted to and

approved by the District prior to issuance of the

ATC/PTO. The owner/operator may petition in writing

for a change to the plan at any time.

The Plan shall include the following:

(a) The manufacturer, model number, unit

identification (e.g. serial) number, rated

horsepower, and combustion method (i.e., rich-burn

or lean-burn or diesel) of each engine and the

fuel type.

(b) A description of the NOx control system installed

on the engine (if any), including unit

identification (e.g. serial) number, type (e.g.,

nonselective catalyst, "clean-burn" combustion,

etc.) and manufacturer, as well as a description

of any ancillary equipment related to the control

of emissions (e.g., automatic air/fuel ratio

controller, fuel valves, etc.). The operator

shall notify the District of any replacement of

such device(s) and the new serial or

identification numbers.

(c) The facility, company, Permit to Operate numbers

and the location of the engine by a schematic of

the affected facilities.

(d) A specific emission inspection procedure for each

engine to ensure that the engine is operated in

strict accordance with the manufacturer's

specifications and in continual compliance with

the provisions of this rule.

(e) The procedure shall include an operator's

inspection schedule.

(D) Exemptions

The provisions of this rule shall not apply to the

operation of internal combustion engines used under the

following conditions:

(1) All internal combustion engines rated at less than

1,000 brake-horsepower.

(2) Engines operated within the District for less than 100

hours within any continuous four consecutive calendar

quarter period.

(3) Emergency pumping (fire fighting, sewage pumping, flood


(4) Emergency IC engines.

Any facility claiming any of the above exemptions shall

maintain records in the manner prescribed by the APCO

to provide documentation for compliance determination.

(E) Monitoring and Records

(1) Monitoring

(a) Operator's of internal combustion engines subject

to this rule shall conduct their inspections,

which ever is the more frequent of, at least

every calendar quarter or after every 2,000 hours

of engine operation . In no event shall the

frequency of inspection be less than once per


(b) Compliance shall be verified at least once in

every 12 months, unless otherwise specified by

the District, by an emissions compliance test. At

a minimum, emissions compliance testing shall be

conducted for NOx, ROC, CO and O2 levels in

conformity with the provisions of the District's

Compliance Test Procedural Manual.

(2) Recordkeeping Requirements

The operator of any engine subject to the provisions of

Section (C) of this rule shall maintain a log for each

engine containing, at a minimum, the following data:

(a) District ATC/PTO number, unit identification

number and NOx control device identification

number, when applicable.

(b) Quarterly fuel use and quarterly hours of

operation, on a calendar quarter basis.

(c) The date and a summary of any emissions corrective

maintenance taken.

(d) Any additional information required in the

facility's District approved Emission Control &

Mitigation Plan, when applicable.

The operator shall maintain the logs on site for a

period of 2 years after the date of each entry. The

log shall be provided to the District upon request.

(F) Test Methods

(1) Oxides of nitrogen emissions for compliance tests shall

be determined by EPA Method 7E.

(2) Carbon monoxide emissions for compliance tests shall be

determined by using EPA Method 10.

(3) The measurement of ROC emissions subject to Section (E)

of this rule shall be conducted in accordance with EPA

Methods 18, 25 and/or 25A (40 CFR 60, Appendix A) as

they exist on (date of adoption) and test procedures

should be performed in accordance with a protocol

approved by the APCO.

(4) Oxygen content for compliance tests shall be determined

by using EPA Method 3A.