(Adopted: 01/23/12) 

MDAQMD Rule 1160.1 1160.1-1

Internal Combustion Engines in Agricultural Operations 

RULE 1160.1 

Internal Combustion Engines in Agricultural Operations

(A) General 

(1) Purpose: 

(a) The purpose of this rule is to limit the emissions of Oxides of Nitrogen 

(NOx), Carbon Monoxide (CO), and Volatile Organic Compounds (VOC) 

from Internal Combustion Engines used in Agricultural Operations. 

(2) Applicability: 

(a) This rule applies to any Internal Combustion Engine used in an 

Agricultural Operation with a Rated Brake Horsepower of fifty (50) or 

more.

(B) Definitions 

(1) “Agreement to Electrify” – A binding, non-cancelable contract written by the 

APCO and signed by the operator and the APCO within sixty (60) days of the 

date of adoption of this rule that commits the operator to complying with the 

requirements of subsection (C)(1)(a) or subsection (C)(1)(b) of this rule by 

electrifying. 

(2) “Agricultural Operation” – The growing and harvesting of crops or the raising of 

fowl or animals for the primary purpose of making a profit, providing a 

livelihood, or conducting agricultural research or instruction by an educational 

institution. Agricultural Operations do not include activities involving the 

processing or distribution of crops or fowl. 

(3) “Air Pollution Control Officer” (APCO) – The Person appointed to the position of 

Air Pollution Control Officer of the District pursuant to the provisions of 

California Health and Safety Code §40750 and his or her designee. 

(4) “Airborne Toxic Control Measure (ATCM) for Stationary Compression Ignition 

Engines” – The most recent version of the ATCM contained in Title 17 of the 

California Code of Regulations §§93115 through 93115.15. 

(5) “California Air Resources Board” (CARB) – The California State Air Resources 

Board, the powers and duties of which are described in Part 2 of Division 26 of 

the California Health & Safety Code (commencing with section 39500). 

(6) “California Reformulated Gasoline” – Gasoline meeting CARB requirements for 

motor vehicle fuel in accordance with California Code of Regulations, Chapter 5, 

Article 1, Subarticle 2 - Standards for gasoline sold beginning March 1, 1996. 
1160.1-2 MDAQMD Rule 1160.1 

Internal Combustion Engines in Agricultural Operations 

(7) “Certified Compression-Ignited Engine” – A Tier 1, Tier 2, Tier 3, or Tier 4 

Compression-Ignited Engine that is USEPA certified as specified in Title 40 Code 

of Federal Regulations Part 89 or in Title 40 Code of Federal Regulations Part 

1039. 

(8) “Certified Spark-Ignited Engine” – A Spark-Ignited engine that is used 

exclusively in Agricultural Operations and that is CARB certified as specified in 

Title 13, Division 3, Chapter 9, Article 4.5, Section 2433 of the California Code 

of Regulations and that has been certified to meet a certification level for 

hydrocarbon plus NOx emissions of 0.6 grams/bhp-hr (40.2 ppmv) or less.

(9) “Carbon Monoxide” (CO) – A colorless, odorless gas resulting from the 

incomplete combustion of hydrocarbon fuels. 

(10) “Compression-Ignited Internal Combustion Engine” – An internal combustion 

engine with operating characteristics significantly similar to the theoretical diesel 

combustive cycle. The regulation of power by controlling fuel supply in lieu of a 

throttle is indicative of a compression ignited engine. 

(11) “De-rated Engine” – An Internal Combustion Engine which has been physically 

limited and restricted by permit condition to an operational level of less than fifty 

(50) horsepower. 

(12) “Diesel Engine” – A Compression-Ignited Internal Combustion Engine. 

(13) “Disaster or State of Emergency” – A fire, Flood, earthquake, or other similar 

natural catastrophe. 

(14) “Emissions Unit” – Any article, machine, equipment, other contrivance or 

combination thereof which emits or has the potential to emit any Regulated Air 

Pollutant. 

(15) “Exhaust Control” – A device or technique used to treat an engine’s exhaust to 

reduce NOx, VOC, or CO emissions, and includes, but is not limited to, catalysts, 

afterburners, reaction chambers, and chemical injectors. 

(16) “Facility” – Any building, structure, Emissions Unit, combination of Emissions 

Units, or installation which emits or may emit a Regulated Air Pollutant and 

which is: 

(a) Located on one or more contiguous or adjacent properties within the 

District; 

(b) Under the control of the same Person (or by Persons under common 

control); and 

(c) Belong to the same industrial grouping, as determined by being within the 

same two digit Standard Industrial Classification Code (SICC). 
MDAQMD Rule 1160.1 1160.1-3

Internal Combustion Engines in Agricultural Operations 

(d) For the purpose of this regulation, such above-described grouping, 

remotely located but connected only by land carrying a pipeline, shall not 

be considered one (1) Facility as defined in Rule 1301 - Definitions. 

(17) “Flood” – A sudden and reasonably unforeseen rising and overflowing of a body 

of water especially onto normally dry land. 

(18) “Gaseous Fuel” – A fuel which is a gas at standard conditions including but not 

limited to natural gas, methane, ethane, propane, butane and liquefied petroleum 

gas (LPG). 

(19) “Installation Date” – The date that an Internal Combustion Engine is initially 

placed at a Location in order to be operated for the first time in its lifetime. 

(20) “Intermittently-Used Engine” – An engine that is used no more than 2400 total 

hours over its lifetime. 

(21) “Internal Combustion Engine” – An engine featuring intermittent combustion 

within one or more internal chambers to produce useful work by applying a 

varying force against a reciprocating piston. 

(22) “Lean-Burn Engine” – Any Spark-Ignited Internal Combustion Engine that is 

operated with an exhaust stream oxygen concentration of four (4) percent by 

volume, or greater prior to any exhaust stream control device. 

(23) “Location” – Any single site at a building, structure, Facility, or installation. 

(24) “Low-Use Engine” – An engine that is used less than 200 hours per year, is a Tier 

3 or cleaner engine (or is replaced not later than January 1, 2020), and generates a 

maximum potential health risk at any residential area, school or hospital of less 

than ten (10) chances per million. 

(25) “Mobile Agricultural Equipment” – Equipment at an Agricultural Operation 

which is towed or mounted on a vehicle and is continuously moved during the 

operation of the equipment. Mobile Agricultural Equipment includes, but is not 

limited to sprayers, balers, and harvest equipment.

(26) “Oxides of Nitrogen” (NOx) – Calculated as equivalent nitrogen dioxide (NO2). 

(27) “Public Utilities Commission (PUC) Quality Natural Gas” – PUC Quality Natural 

Gas means high methane gas (at least eighty (80) percent methane by volume) as 

specified in PUC General order 58-A. 

(28) “Rated Brake Horsepower” – The continuous brake horsepower rating specified 

for the engine by the manufacturer or listed on the nameplate of the unit, unless 

otherwise physically limited and specified by a condition on the engine's permit 

or Rule 114 registration. 
1160.1-4 MDAQMD Rule 1160.1 

Internal Combustion Engines in Agricultural Operations 

(29) “Regulated Air Pollutant” – Any of the following Air Pollutants: 

(a) Any air pollutant, and its precursors, for which an Ambient Air Quality 

Standard has been promulgated. 

(b) Any air pollutant that is subject to a standard under 42 U.S.C. §7411, 

Standards of Performance for New Stationary Sources (Federal Clean Air 

Act §111) or the regulations promulgated thereunder. 

(c) Any substance which has been designated a Class I or Class II substance 

under 42 U.S.C. §7671a (Federal Clean Air Act §602) or the regulations 

promulgated thereunder. 

(d) Any Air Pollutant subject to a standard or other requirement established 

pursuant to 42 U.S.C. §7412, Hazardous Air Pollutants (Federal Clean Air 

Act §112) or the regulations promulgated thereunder. 

(30) “Remotely Located Engine” – An engine that is at least one half (1/2) mile away 

from a residential area, school, or hospital.

(31) “Replacement Engine” – An engine that is installed to replace an engine that was 

in place as of June 16, 2005 and that such replacement is performed solely for the 

purpose of complying with the requirements of subsection (C)(1) of this rule. 

(32) “Rich-Burn Engine” – Any Spark-Ignited Internal Combustion Engine that is 

operated with an exhaust stream oxygen concentration of less than four (4) 

percent by volume prior to any Exhaust Control device. 

(33) “Spark-Ignited Internal Combustion Engine” – A liquid or Gaseous Fueled engine 

designed to ignite its air/fuel mixture by a spark across a spark plug. 

(34) “Tier 1 Engine, Tier 2 Engine, Tier 3 Engine, and Tier 4 Engine” – A 

Compression-Ignited Engine that is certified to meet the Tier 1, Tier 2, Tier 3, or 

Tier 4 Off-Road Compression-Ignited Certification Standards as specified in title

13, California Code of Regulations, section 2423. 

(35) “United States Environmental Protection Agency” (USEPA) – The USEPA, the 

Administrator of the USEPA and his or her authorized representative. 

(36) “Volatile Organic Compound” (VOC) – Any compound of carbon, excluding 

carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates, 

and ammonium carbonate, which participates in atmospheric photochemical 

reactions other than those compounds listed in 40 CFR 51.100(s). 

(37) “Waste Gas” – An untreated, raw gas derived through a natural process, such as 

anaerobic digestion, from the decomposition of organic waste at municipal solid 

waste landfills or publicly owned wastewater treatment facility. Waste Gas 

includes landfill gas which is generated at landfills, digester gas which is 

generated at sewage treatment facilities, or a combination of the two. 
MDAQMD Rule 1160.1 1160.1-5

Internal Combustion Engines in Agricultural Operations 

(38) “Wind Machine” – A machine consisting of a large fan mounted on a tower 

powered by an Internal Combustion Engine, used exclusively to provide 

protection to crops, including, but not limited to oranges, lemons, and grapes, 

from cold weather by effecting a heat transfer by moving warmer atmospheric air 

downward and mixing it with the colder air surrounding a crop. 

(C) Requirements 

(1) Engine Emission Standards and Compliance Schedules 

(a) Spark-Ignited Internal Combustion Engines 

(i) Emission Limits/Standards: 

The owner of a Spark-Ignited Internal Combustion Engine shall 

not operate it in such a manner that results in emissions exceeding 

the limits in Table 1 below. 

Table 1 

Emission Limits/Standards and Compliance Schedule for a Spark-Ignited Internal Combustion 

Engine (corrected to fifteen (15) percent oxygen on a dry basis) 

Engine Type NOx CO VOC 

Rich Burn 90 ppmv or 

80% reduction 2000 ppmv 250 ppmv 

Lean Burn 150 ppmv or 

70% reduction 2000 ppmv 750 ppmv 

(ii) Replacement Restriction: 

a. The owner of a Spark-Ignited Internal Combustion Engine 

shall not replace such engine with an engine that emits 

more emissions of NOx, VOC, and CO, on a ppmv basis, 

(corrected to fifteen (15) percent oxygen on a dry basis) 

than the engine being replaced. 

(iii) Compliance Schedule: 

a. The owner of a Spark-Ignited Internal Combustion Engine 

that is subject to the requirements of this rule shall be in 

full compliance with this rule not later than six (6) months 

after the date of adoption of this rule; or 

b. If the owner has an Agreement to Electrify, the owner shall 

be in full compliance with the requirements of this rule not 

later than eighteen (18) months after the date of adoption of 

this rule. 

(iv) Fuel Requirement: 

a. California Reformulated Gasoline, as defined in Title 13 

California Code of Regulations, Chapter 5, article 1, 

subarticle 2, shall be used as the fuel for all gasoline-fired, 

Spark-Ignited Internal Combustion Engines. 
1160.1-6 MDAQMD Rule 1160.1 

Internal Combustion Engines in Agricultural Operations 

(b) Compression-Ignited Internal Combustion Engines

(i) Emission Limits/Standards and Compliance Schedules: 

a. The owner of a Compression-Ignited Internal Combustion 

Engine shall repower, replace or control the engine to 

comply with the applicable limits/standards and compliance 

dates in the ATCM for Stationary Compression Ignition 

Engines. 

(ii) Replacement Restriction: 

a. The owner of a Compression-Ignited Internal Combustion 

Engine that is subject to the requirements of subection 

(C)(1) shall not replace such engine with an engine, that 

emits more emissions of NOx, VOC, and CO, on a ppmv 

basis, (corrected to fifteen (15) percent oxygen on a dry 

basis) than the engine being replaced. 

(iii) Fuel Requirement: 

a. California ultra low sulfur diesel, as defined in Title 13, 

California Code of Regulations, section 2281, or the 

equivalent shall be used as the fuel for all liquid fired 

Compression-Ignited Engines. 

(2) Submission of Emission Control Plan (ECP), Inspection and Monitoring (I&M) 

Plan, and/or Authority to Construct (ATC) Application. 

(a) The owner of an engine that is required to submit an ATC application, an 

ECP required pursuant to subsection (D)(2) or I&M Plan required 

pursuant to subsection (D)(3), shall submit the required document(s) no 

later sixty (60) days of the date of adoption of this rule, or within sixty 

(60) days of becoming subject to this rule. 

(D) Administrative Requirements 

(1) Permanent Removal of an Engine 

The owner of an engine who elects to permanently remove the engine from 

service shall comply with all of the following conditions: 

(a) Comply with all applicable requirements of this rule until the engine is 

permanently removed from service; 

(b) Submit a letter of intent to the APCO no later than fourteen (14) days 

before the engine is permanently removed from service, stating the intent 

to permanently remove the engine from service. The engine removal letter 

can be submitted with the ECP for the Replacement Engine, if any; and 

(c) Permanently remove the engine from service and officially surrender the 

permit or Rule 114 registration to the APCO no later than thirty (30) days 

after the engine is permanently removed from service. 
MDAQMD Rule 1160.1 1160.1-7

Internal Combustion Engines in Agricultural Operations 

(2) Emission Control Plan (ECP) 

The owner of an engine subject to the requirements of subsection (C)(1), of this 

rule shall submit to the APCO an APCO-approvable ECP of all actions to be taken 

to satisfy the emission requirements of subsection (C)(1) within sixty (60) days of 

the engine becoming subject to this rule. 

(a) The requirement to submit an ECP shall not apply to an engine specified 

below: 

(i) A Certified Spark-Ignited Engine that has not been retrofitted with 

an Exhaust Control or catalytic emission control device and is in 

compliance with the requirements of subsection (C)(1)(a); 

(ii) A Certified Compression-Ignited Engine that has not been 

retrofitted with an Exhaust Control and is in compliance with the 

requirements of subsection (C)(1)(b); or 

(iii) An engine with an operating Exhaust Control system that has been 

certified in accordance with subsection (D)(4) Exhaust Control 

System Certification Requirements. 

(b) An ECP shall contain the following information, as applicable for each 

engine: 

(i) Permit number, or Rule 114 registration number;

(ii) Engine manufacturer; 

(iii) Model designation and engine serial number; 

(iv) Rated Brake Horsepower; 

(v) Type of fuel and type of ignition; 

(vi) Combustion type: Rich-Burn or Lean-Burn Engine; 

(vii) Total hours of operation in the previous one (1) year period, 

including typical daily operating schedule; 

(viii) Fuel consumption (cubic feet for gas or gallons for liquid) for the 

previous one (1) year period; 

(ix) Stack modifications to facilitate continuous in-stack monitoring 

and to facilitate source testing; 

(x) Type of control to be applied, including in-stack monitoring 

specifications; 

(xi) Applicable emission limits; 

(xii) Documentation showing existing emissions of NOx, VOC, and CO; 

and 

(xiii) Date that the engine will be in full compliance with this rule. 

(xiv) The ECP shall identify the type of emission control device or 

technique to be applied to each engine and a construction/removal 

schedule, or shall provide support documentation sufficient to 

demonstrate that the engine is in compliance with the emission 

requirements of this rule. 

(xv) For an engine being permanently removed from service, the ECP 

shall include a letter of intent pursuant to subsection (D)(1). 
1160.1-8 MDAQMD Rule 1160.1 

Internal Combustion Engines in Agricultural Operations 

(3) Inspection and Monitoring (I&M) Plan 

The owner of an engine that is subject to the requirements of subsection (C)(1), 

shall submit to the APCO for approval, an I&M Plan. The actions to be identified 

in the I&M Plan shall include, but are not limited to, the information specified 

below: 

(a) The following engines are not required to submit I&M Plans: 

(i) A Certified Engine that has not been retrofitted with an Exhaust 

Control and is in compliance with the requirements of subsection 

(C)(1). 

(ii) An engine with an operating Exhaust Control system that has been 

certified in accordance with subsection (D)(4), Exhaust Control 

System Certification Requirements. 

(b) Procedures requiring the owner or operator to establish ranges for control 

equipment parameters, engine operating parameters, and engine exhaust 

oxygen concentrations that source testing has shown result in pollutant 

concentrations within the rule limits. 

(c) Procedures for monthly inspections as approved by the APCO. The 

applicable control equipment parameters and engine operating parameters 

will be inspected and monitored monthly in conformance with a regular 

inspection schedule listed in the I&M Plan. 

(d) Procedures for the corrective actions on the noncompliant parameter(s) 

that the owner or operator will take when an engine is found to be 

operating outside the acceptable range for control equipment parameters, 

engine operating parameters, and engine exhaust NOx, CO, VOC, or 

oxygen concentrations. 

(e) Procedures for the owner or operator to notify the APCO when an engine 

is found to be operating outside the acceptable range for control 

equipment parameters, engine operating parameters, and engine exhaust 

NOx, CO, VOC, or oxygen concentrations. 

(f) Procedures for preventive and corrective maintenance performed for the 

purpose of maintaining an engine in proper operating condition. 

(g) Procedures and a schedule for using a portable NOx analyzer to take NOx

emission readings pursuant to subsection (F)(6)(a)(iii). 

(h) Procedures for collecting and recording required data and other 

information in a form approved by the APCO including, but not limited to, 

data collected through the I&M Plan and the monitoring systems described 

in section (F). Data collected through the I&M Plan shall have retrieval 

capabilities as approved by the APCO. 
MDAQMD Rule 1160.1 1160.1-9

Internal Combustion Engines in Agricultural Operations 

(i) Procedures for revising the I&M Plan. The I&M Plan shall be updated to 

reflect any change in operation. The I&M Plan shall be updated prior to 

any planned change in operation. An engine owner that changes 

significant I&M Plan elements must notify the District no later than seven 

(7) days after the change and must submit an updated I&M Plan to the 

APCO no later than fourteen (14) days after the change for approval. The 

date and time of the change to the I&M Plan shall be recorded in the 

engine operating log. For new engines and modifications to existing 

engines, the I&M Plan shall be submitted to and approved by the APCO 

prior to issuance of the permit or Rule 114 registration. The owner of an 

engine may request a change to the I&M Plan at any time. 

(4) Exhaust Control System Certification Requirements 

(a) A system not certified by CARB shall be certified by the APCO and 

comply with the requirements of subsections (D)(4)(b) through (D)(4)(c). 

(b) To be considered for APCO certification, the manufacturer or operator 

shall comply with all of the following requirements: 

(i) Certification shall be based upon the emission source testing 

results of a specific Exhaust Control system. 

(ii) A source testing protocol shall be submitted for approval by the 

APCO prior to conducting the source test. The source testing 

protocol approved by the APCO shall be strictly adhered to during 

certification source testing. 

(iii) Source testing shall be conducted over the range of operating 

parameters for which the unit(s) will be operated. 

(iv) The source testing results shall demonstrate compliance with the 

emission limits of this rule for each model of Exhaust Control 

system(s) to be certified. 

(v) The source testing procedure and reports shall be prepared by a 

CARB approved independent testing laboratory, and shall contain 

all the elements identified in the APCO-approved source testing 

protocol. 

(vi) Source testing shall be conducted no more than ninety (90) days 

prior to the date of submission of request for certification by the 

APCO. 

(vii) Any additional supporting information required by the APCO to 

address other performance parameters. 

(c) The manufacturer or operator requesting certification shall submit to the 

APCO the following information: 

(i) Copies of the source testing results conducted pursuant to the 

requirements of subsection (D)(4)(b), and other pertinent technical 

data to demonstrate compliance with the emission limits of this 

rule. 
1160.1-10 MDAQMD Rule 1160.1 

Internal Combustion Engines in Agricultural Operations 

(ii) The applicant shall sign and date the statement attesting to the 

accuracy of all information in the statement. 

(iii) Name and address of the Exhaust Control system manufacturer or 

operator, brand name of the Exhaust Control unit, model number, 

and description of model of system(s) being certified. 

(d) The APCO will only approve an application for certification to the extent 

that the requirements of subsections (D)(4)(b) through (D)(4)(c) are met 

and the source testing results demonstrate that the emission limits of this 

rule are met. 

(e) The APCO-approved certification is valid only for the range of operating 

parameters and conditions for which certification is issued. 

(f) The APCO shall publish a list of certified Exhaust Control Systems after 

the certification process is completed. 

(E) Exemptions 

(1) The requirements of this rule shall not apply to the following engines: 

(a) An engine used to propel implements of husbandry, as that term is defined 

in section 36000 of the California Vehicle Code, as that section existed on 

January 1, 2003. 

(b) An engine used exclusively to power a Wind Machine. 

(c) A De-rated Engine less than 50 horsepower, provided the de-rating 

occurred before June 1, 2005. 

(d) An engine used exclusively to power Mobile Agricultural Equipment. 

(2) Except for the requirements of subsection (F)(4), the requirements of this rule 

shall not apply to an Intermittently-Used Engine, Low-Use Engine or Remotely 

Located Engine provided the District agricultural engine registration specifies the 

exempt status. In lieu of a non-resettable hour meter, the owner of an emergency 

engine may use an alternative device, method, or technique, in determining 

operating time provided that the alternative is approved by the APCO. The owner 

of the engine shall properly maintain and operate the hour meter or alternative 

device in accordance with the manufacturer’s instructions. 

(3) Except for the administrative requirements of subsection (F)(5)(b), the 

requirements of this rule shall not apply to an Internal Combustion Engine 

registered as a portable engines under the Statewide Portable Equipment 

Registration Program pursuant to sections 2450-2465, Article 5, Title 13, 

California Code of Regulations. 
MDAQMD Rule 1160.1 1160.1-11

Internal Combustion Engines in Agricultural Operations 

(4) Loss of Exemption 

The owner of an engine which becomes subject to the emission limits/standards of 

this rule through loss of exemption shall not operate the subject engine, except as 

required for obtaining a new or modified permit or Rule 114 registration for the 

engine, until the owner demonstrates that the subject engine is in full compliance 

with the requirements of this rule. 

(F) Monitoring and Recordkeeping Requirements 

(1) Continuous Emissions Monitoring Systems (CEMS) 

(a) All CEMS emissions measurements shall be averaged over a period of 

fifteen (15) consecutive minutes. Any fifteen (15) consecutive minute 

block average CEMS measurement exceeding the applicable emission 

limits of this rule shall constitute a violation of this rule. 

(2) Percent emission reductions, if used to comply with the NOx emission limits of 

subsection (C)(1), shall be calculated as follows: 

(a) For engines with external control devices that are not operated in 

combination with a second emission control device or technique, percent 

reduction shall be calculated using emission samples taken at the inlet and 

outlet of the control device. 

(b) For engines without external control devices and for engines with an 

external control device in combination with a second emission control 

device or technique, percent reduction shall be based on source test results 

for the uncontrolled engine and the engine after the control device or 

technique has been employed. In this situation, the engine’s typical 

operating parameters, loading, and duty cycle shall be documented and 

repeated at each successive post-control source test to ensure that the 

engine is meeting the percent reduction limit. When representative source 

sampling prior to the application of an emissions control technology or 

technique is not available, the APCO may approve the use of a 

manufacturer’s uncontrolled emissions information or source sampling 

from a similar, uncontrolled engine. 

(3) The owner of an Internal Combustion Engine that uses percent emission reduction 

to comply with the NOx emission limits of subsection (C)(1) shall provide an 

accessible inlet and outlet on the external control device or the engine as 

appropriate for taking emission samples and as approved by the APCO. 

(4) Engine Monitoring Requirements 

The owner of any engine subject to this rule shall:

(a) Properly operate and maintain each engine as recommended by the engine 

manufacturer or emission control system supplier. 
1160.1-12 MDAQMD Rule 1160.1 

Internal Combustion Engines in Agricultural Operations 

(b) Monitor the operational characteristics of each engine as recommended by 

the engine manufacturer or emission control system supplier. 

(c) Install and operate a non-resettable hour meter. In lieu of installing a nonresettable hour meter, the owner of an engine may use an alternative 

device, method, or technique, in determining operating time provided that 

the alternative is approved by the APCO and CARB and is allowed by 

permit or Rule 114 registration condition. The owner of the engine shall 

properly maintain and operate the hour meter or alternative device in 

accordance with the manufacturer’s instructions. 

(d) The owner of an Spark-Ignited Internal Combustion Engine that has been 

retrofitted with a NOx Exhaust Control that has not been certified in 

accordance with subsection (D)(4) Exhaust Control System Certification 

Requirements, or a Compression-Ignited Engine that has been retrofitted 

with a NOx Exhaust Control shall use a portable NOx analyzer to take NOx 

emission readings to demonstrate compliance with the emission 

requirements of subsection (C)(1), in compliance with the following: 

(i) The owner of a Compression-Ignited Engine that is subject to the 

limits/standards of subsection (C)(1), shall use a portable NOx

analyzer to take NOx emission readings at least once every six (6) 

months that the engine is operated. 

(ii) The owner of any other engine that has been retrofitted with a NOx

Exhaust Control shall use a portable NOx analyzer to take NOx

emission readings at least once every twenty-four (24) months that 

the engine is operated. 

(iii) All emission readings shall be taken with the engine operating 

either at conditions representative of normal operations or 

conditions specified in the permit or Rule 114 registration. 

(iv) The NOx analyzer shall be calibrated, maintained, and operated in 

accordance with the manufacturer’s specifications and 

recommendations or a protocol approved by the APCO.

(v) All NOx emissions readings shall be reported to the APCO in a 

manner approved by the APCO. 

(vi) NOx emission readings taken pursuant to this section shall be 

averaged over a fifteen (15) consecutive-minute period by either 

taking a cumulative fifteen (15) consecutive-minute sample 

reading or by taking at least five (5) readings evenly spaced out 

over the fifteen (15) consecutive-minute period. 

(vii) A NOx emission reading violation as determined by the portable 

NOx analyzer shall constitute a violation of this rule. 

(5) Recordkeeping 

(a) The owner of an engine subject to the requirements of subsection (C)(1) of 

this rule shall maintain an engine operating log to demonstrate compliance 

with this rule. This information shall be retained for a period of at least 

five (5) years, shall be readily available, and be made available to the 
MDAQMD Rule 1160.1 1160.1-13

Internal Combustion Engines in Agricultural Operations 

APCO upon request. The engine operating log shall include, on a monthly 

basis, the following information: 

(i) Total hours of operation; 

(ii) Type of fuel used; 

(iii) Maintenance or modifications performed; 

(iv) Monitoring data; 

(v) Compliance source test results; 

(vi) Any other information necessary to demonstrate compliance with 

this rule; and 

(vii) The quantity (cubic feet of gas or gallons of liquid) of fuel used. 

(b) An owner claiming an exemption under subsection (E)(2) or subsection 

(E)(3) shall maintain annual operating records. This information shall be 

retained for at least five (5) years, shall be readily available, and provided 

to the APCO upon request. The records shall include, but are not limited 

to, the following: 

(i) Total hours of operation; 

(ii) The type of fuel used; 

(iii) The purpose for operating the engine; 

(iv) For Emergency Standby Engines, all hours of non-emergency and 

emergency operation shall be reported; and 

(v) Other support documentation necessary to demonstrate claim to the 

exemption. 

(6) Compliance Testing 

The owner of an engine subject to the requirements of subsection (C)(1), shall 

comply with the following requirements, except for an engine specified in 

subsection (D)(2)(a): 

(a) Demonstrate compliance with applicable limits, ppmv or percent 

reduction, in accordance with the test methods in section (G), as specified 

below: 

(i) By the applicable date specified in subsection (C)(1)(a), subsection 

(C)(1)(b), and at least once every twenty-four (24) months 

thereafter. 

(ii) By the applicable date specified in subsection (C)(1)(a), subsection 

(C)(1)(b), and at least once every sixty (60) months thereafter, for 

a Spark-Ignited engine that has been retrofitted with a catalytic 

emission control device. 

(iii) A portable NOx analyzer may be used to show initial compliance 

with the applicable limits/standards in subsection (C)(1) for spark 

ignited engines, provided the following criteria are met, and a 

source test is conducted within twelve (12) months from the 

required compliance date. 
1160.1-14 MDAQMD Rule 1160.1 

Internal Combustion Engines in Agricultural Operations 

a. A minimum of fifteen (15) minutes of runtime must be 

measured with data recorded at a minimum of fifteen (15), 

evenly spaced time intervals. Compliance is to be 

determined with the arithmetic average of the oxygencorrected data. 

b. The NOx analyzer shall be calibrated, maintained, and 

operated in accordance with the manufacturer’s 

specifications and recommendations or a protocol approved 

by the APCO. Analyzer calibration records shall be made 

available at the District’s request. 

c. The NOx analyzer shall be checked with USEPA protocol 

span gas at the beginning and end of each test day. The 

results of these checks shall be recorded and copies 

submitted to the District with each engine test. If the NOx

analyzer exhibits more than a ten (10) percent deviation 

from the span check, the instrument must be re-calibrated. 

Any analysis performed prior to an end-of-day span check 

failure shall be void. 

d. The test results of each engine, including span check 

results, shall be submitted to the District within thirty (30) 

days of the test date. Test results shall clearly identify the 

engine tested including owner, Location, permit or 

registration number, manufacturer, model, and serial 

number. 

e. The NOx analyzer utilized for each check shall be clearly 

identified in the material submitted with the test results. 

Identification shall include manufacturer and serial number 

of the analyzer used, and the last calibration date. 

(b) Conduct emissions source testing with the engine operating either at 

conditions representative of normal operations or conditions specified in 

the permit or Rule 114 registration. For emissions source testing 

performed pursuant to subsection (F)(6) for the purpose of determining 

compliance with an applicable standard or numerical limitation, the 

arithmetic average of three (3), thirty (30), consecutive minute test runs 

shall apply. If two (2) of three (3) runs are above an applicable limit, the 

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

VOC shall be reported as methane. VOC, NOx, and CO concentrations 

shall be reported in ppmv, corrected to fifteen (15) percent oxygen. For 

engines that comply with a percent reduction limit in Table 1, the percent 

reduction of NOx emissions shall also be reported. 

(c) In addition to other information, the source test protocol shall describe 

which critical parameters will be measured and how the appropriate range 

for these parameters shall be established. The range for these parameters 

shall be incorporated into the I&M Plan. 

(d) Engines that are limited by permit or Rule 114 registration condition to be 

fueled exclusively with Public Utilities Commission Quality Natural Gas 
MDAQMD Rule 1160.1 1160.1-15

Internal Combustion Engines in Agricultural Operations 

shall not be subject to the reoccurring source test requirements of 

subsection (F)(6) for VOC emissions. 

(e) Representative Testing 

For Spark-Ignited Internal Combustion Engines, in lieu of compliance 

with the applicable requirements of subsection (F)(6), compliance with the 

applicable emission limits in subsection (C)(1) shall be demonstrated by 

submittal of annual emission test results, within thirty (30) days of the test 

date, to the District, from a unit or units that represents a specified group 

of units, provided all of the following are requirements are satisfied: 

(i) The units are located at the same Facility; 

(ii) The units were produced by the same manufacturer, have the same 

model number or other manufacturer’s designation in common, 

and have the same rated capacity and operating specifications; 

(iii) The units are operated and maintained in a similar manner; and 

(iv) At least twenty (20) percent of the total number of units are tested 

during each annual test cycle. 

(v) The District, based on documentation submitted by the Facility: 

a. Determines that the margin of compliance for the identical 

units tested is significant and can be maintained on an ongoing basis; or 

b. Determines based on a review of sufficient emissions data 

that, though the margin of compliance is not substantial, 

other factors allow for the determination that the variability 

of emissions for identical tested units is low enough for 

confidence that the untested unit will be in compliance. 

These factors may include, but are not limited to, the 

following: 

1. Historical records at the tested unit showing 

consistent invariant load; 

2. Fuel characteristics yielding low variability and 

therefore assurance that emissions will be constant

and below allowable levels; and/or 

3. Statistical analysis of a robust emissions data set 

demonstrates sufficiently low variability to convey

assurance that the margin of compliance, though 

small, is reliable. 

(f) Should any of the representative units exceed the required emission limits, 

or if the District notifies the operator that the criteria in subsection 

(F)(6)(e) has not been fulfilled, each of the units in the group shall 

individually demonstrate compliance by emissions testing. Failure to 

complete emissions testing within ninety (90) days of the failed test shall 

result in the untested units being in violation of this rule. After 

compliance with the requirements of subsection (F)(6)(e) has been 

demonstrated, subsequent source testing shall be performed pursuant to 

subsections (F)(6)(a) through (F)(6)(c). 
1160.1-16 MDAQMD Rule 1160.1 

Internal Combustion Engines in Agricultural Operations 

(G) Test Methods 

Compliance with the requirements of subsection (C)(1) shall be determined, as required, 

in accordance with the following test procedures or any other method approved by 

USEPA and the APCO: 

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

(2) Carbon monoxide - EPA Method 10, or ARB Method 100. 

(3) Stack gas oxygen - EPA Method 3 or 3A, or ARB Method 100. 

(4) Volatile organic compounds - EPA Method 25A or 25B, or ARB Method 100. 

(5) Operating horsepower determination - any method approved by EPA and the 

APCO. 

See SIP Table at http://www.mdaqmd.ca.gov/Modules/ShowDocument.aspx?documentid=45