SAN JOAQUIN VALLEY UNIFIED AIR POLLUTION CONTROL DISTRICT 

DRAFT STAFF REPORT FOR 

DRAFT AMENDMENTS TO RULE 4702 (Internal Combustion Engines – Phase 2)

September 9, 2010 

Prepared by: Joven R. Nazareno, Senior Air Quality Engineer 

Reviewed by: Brian Clements, Senior Air Quality Engineer 

 Patrick Houlihan, Senior Air Quality Specialist 

 Kevin McCaffrey, Senior Air Quality Specialist 

 George Heinen, Supervising Air Quality Engineer 

 Errol Villegas, Planning Manager 

 

 

I. SUMMARY 

District staff is proposing to amend the rule in order to implement a control measure in 

the District’s 2007 Ozone Plan and 2008 PM2.5 Plan. Details of the proposed changes 

to the rule are discussed later in Section VI of this report. The proposed changes would 

apply only to non-emergency, non-low-use spark-ignited engines that are used in nonagricultural operations (Non-AO). This rule-amending project would strengthen rule 

requirements by proposing the changes to Rule 4702 as follows: 

• Lower the applicability of the rule so it would apply to internal combustion engines 

(ICEs) rated at 25 brake horsepower (bhp) or greater. Spark-ignited engines and 

compression-ignited engines rated at 25 to 50 bhp are already subject to existing 

federal Standards of Performance so the District would include a point-of-sale 

provision in Draft Rule 4702 to ensure that only compliant ICEs are sold in the 

District. Owners of engines rated at 25 to 50 bhp that are used in non-agricultural 

operations (Non-AO) would be required to report their ICEs to the District. The report 

would include information on the engine size, model year, manufacturer, location of 

the engine, the type of fuel used, and engine operating hours. 

• Lower the current Oxides of Nitrogen (NOx) limit from 25/65 ppmv to 11 ppmv 

(corrected to 15% O2) for spark-ignited engines greater than 50 bhp that are used in 

Non-AO, except for cyclic loaded field gas fueled spark-ignited engines and waste 

gas fueled spark-ignited engines. 

• Lower the current NOx limit from 50 ppmv to 25 ppmv (corrected to 15% O2) for 

cyclic loaded field gas fueled spark-ignited engines greater than 50 bhp. 

• Lower the current Carbon Monoxide (CO) from 2000 ppmv to 500 ppmv (corrected 

to 15% O2) for Non-AO spark-ignited engines greater than 50 bhp, except for waste 

gas fueled spark-ignited engines. 
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Draft Staff Report: Rule 4702 September 9, 2010 

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• Lower the current VOC from 250 ppmv to 30 ppmv (corrected to 15% O2) for NonAO spark-ignited engines, except for waste gas fueled spark-ignited engines greater 

than 50 bhp. 

• Delete the existing provision for Alternate Emission Control Plan since no engine 

owner is using this alternate compliance option. 

• Include a provision that would allow payment of annual NOx emission fees to the 

District in lieu of complying with the proposed NOx, VOC, and CO emission limits. 

• Include sulfur dioxide (SOx) emission control and monitoring requirements in the 

rule. 

 

II. REASON FOR RULE DEVELOPMENT AND IMPLEMENTATION 

Air monitoring data in the San Joaquin Valley Air Basin (SJVAB) indicates ozone levels 

that exceed the eight-hour ozone National Ambient Air Quality Standards (NAAQS) set 

by the federal government to protect public health and welfare. As a result, the United 

States Environmental Protection Agency (EPA) has classified the Valley as extreme 

nonattainment. In accordance with the requirements of the federal Clean Air Act, 

nonattainment areas must develop plans to achieve attainment of the NAAQS. 

Consequently, the San Joaquin Valley Unified Air Pollution Control District (District), 

adopted the 2007 Ozone Plan. The SJVAB is also currently designated as 

nonattainment for the national ambient air quality standard (NAAQS) for particulate 

matter with aerodynamic diameter of 2.5 micrometers or less (PM2.5). As such, the 

District's Governing Board adopted the 2008 PM 2.5 Plan on April 30, 2008. The 

Ozone Plan and PM2.5 Plan are comprised of regulatory and incentive-based measures 

to reduce emissions of nitrogen oxides (NOx), volatile organic compounds (VOC), 

particulate matter 2.5 microns or less in diameter (PM2.5), and oxides of sulfur (SO2). 

Since amending Rule 4702 (Internal Combustion Engines - Phase 2) is a control 

measure (S-COM-6) commitment in the District’s 2007 Eight-Hour Ozone Plan and 

2008 PM2.5 Plan, it is subject to Code of Federal Regulations (CFR), Clean Air Act 

(CAA), and California Health and Safety Code (CH&SC) requirements. This rulemaking 

project is intended to support the attainment goals of the District’s Ozone Plan and 

PM2.5 Plan. The draft amendments to Rule 4702 will seek to obtain as much reduction 

of NOx, VOC, PM2.5 and SOx from stationary internal combustion engines as is 

expeditiously practicable, technologically feasible, and economically reasonable, as 

determined by the District’s Governing Board. Furthermore, the rule is intended to 

satisfy the Ozone Plan and PM2.5 Plan commitments as identified in Table 1. 
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Draft Staff Report: Rule 4702 September 9, 2010 

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Table 1: Ozone Plan and PM 2.5 Plan Commitments 

Subject Reference Requirement 

Timeline CAA Section 

172(c)(1) 

Ozone attainment plans shall implement control 

measures as expeditiously as practicable, and 

provide for attainment. 

RACT 

CAA Sections 

182(b)(2) and 

182(f) 

Ozone attainment plans shall assure that 

reasonable available control technology (RACT) 

for NOx and volatile organic compounds (VOC) 

is in use at sources and on source categories at 

or above the RACT threshold. 

BARCT CH&SC 

40919(a)(3) 

Ozone attainment plans should provide for best 

available retrofit technology (BARCT) for existing 

permitted sources. 

All Feasible Controls CH&SC 

40914(b)(2) 

Ozone attainment plans should include "all 

feasible control measures." 

Deadline 

District 2007 

Eight-Hour 

Ozone Plan 

and 2008 

PM2.5 Plan 

Rule adoption by the Fourth Quarter of 2010. 

Reductions 

District 2007 

Eight-Hour 

Ozone Plan 

and 2008 

PM2.5 Plan 

The plans did not quantify the reduction in NOx, 

PM2.5 and SOx that could be achieved by 

amending Rule 4702. The emissions reduction 

will be calculated during the rule development 

process. 

III. DESCRIPTION OF THE PROJECT 

A. Purpose of the Rulemaking Project 

The purpose of amending Rule 4702 is to obtain additional emissions reduction of NOx, 

VOC, and SOx from stationary internal combustion engines by implementing Control 

Measure S-COM-6 in the District’s 2007 Ozone Plan and 2008 PM2.5 Plan. The control 

options recommended in the Plans for this source are indicated below. District staff’s 

concepts for addressing the above control options are discussed in the latter part of this 

report. 

• Consider South Coast Air Quality Management District (SCAQMD) Rule 1110.2 

(Emissions from Gaseous- and Liquid-Fueled Internal Combustion Engines). 
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• Consider replacing engines with electric motors where possible. 

• Investigate the feasibility of controlling SOx emissions from natural gas fired 

engines. 

• Implement ARB ATCM for stationary diesel engines through the permitting 

process to control PM emissions (natural gas fuel is inherently low in sulfur 

content). 

B. Rule Amendment Process 

The District’s 2007 Ozone Plan and 2008 PM 2.5 Plan identified Rule 4702 as control 

measure commitment, which would be implemented through the rule development 

process. As part of the rule development process, District staff conducted a Scoping 

meeting on June 24, 2010 to present and discuss the concepts for developing the draft 

amendments to the rule. The comments received from the public, affected sources, 

interested parties during the Scoping Meeting were used to develop the draft 

amendments to the rule. District staff plans to conduct at two public workshops in order 

to refine the draft rule amendments taking into consideration appropriate comments 

from affected sources, EPA, ARB, and the public. The first workshop will be conducted 

in September 2010. The deadline for considering adoption of the draft rule 

amendments by the Governing Board is December 16, 2010. 

 

Pursuant to state law, the District is required to perform a socioeconomic impact 

analysis prior to adoption, amendment, or repeal of a rule that has significant air quality 

benefits or that will strengthen emission limitations. As part of the District 

socioeconomic analysis process, District staff will solicit volunteers from affected 

stakeholders and interested parties to participate as members of the Socioeconomic 

Focus Group. District staff will convene a meeting of the Focus Group in conjunction 

with the first workshop to assist District staff in gathering information on regulatory 

compliance costs and business impacts resulting from compliance with the draft 

amendments. The results of the socioeconomic analysis will be published in a report 

and will be presented along with the draft rule amendments to the public and interested 

parties during the final workshop. 

IV. BACKGROUND 

A. Source Description 

An internal combustion engine (ICE) is any engine that operates by burning its fuel 

inside the engine. ICEs generate power by the combustion of an air/fuel mixture. The 

main types of ICEs are spark-ignited (SI) engines and compression-ignited (or diesel) 

engines. In the case of spark-ignited (SI) engines, a spark plug ignites the air/fuel 

mixture. SI engines come in several designs such as: two-stroke and four-stroke, richburn and lean-burn, turbocharged and naturally aspirated. SI engines may use one or 
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more fuels, such as natural gas, propane, butane, liquefied petroleum gas, oil field gas, 

digester gas, landfill gas, methanol, ethanol, and gasoline. 

Compression-ignited (CI) or diesel engines rely on heating of the inducted air during the 

compression stroke to ignite the injected diesel fuel. Two types of CI engines are twostroke and four-stroke. Most diesel engines are four-stroke, while larger diesel engines 

often are two-stroke. 

 

Most ICEs are used to power pumps, compressors, or electrical generators. ICEs are 

used by a large variety of private businesses and public agencies throughout the 

SJVAB. Examples of businesses and industries that use ICEs that could be affected by 

this project include schools and universities, agriculture, oil and gas production and 

pipelines, petroleum refining, manufacturing facilities, food processing, electrical power 

generation, landfill and waste water treatment facilities, and water districts. Many of the 

permitted compression-ignited engines in the District are used as emergency engines. 

Such emergency engines are used to provide backup power when electric service is 

interrupted. 

B. Emissions Inventory 

Emissions of NOx, PM2.5, and SOx, are generated when the air/fuel mixture is 

combusted in the ICE. The winter season and the annual emissions inventory for ICE 

as indicated in the District’s 2008 PM2.5 Plan is shown below. 

Table 2: Plan Baseline Emissions Inventory

 Pollutant 2005 2009 2010 2011 2012 2013 2014 

Tons/day – Winter Season 

NOx 20.4 20.2 19.9 19.5 19.1 18.7 18.3 

PM2.5 1.1 1.0 1.0 1.0 0.9 0.9 0.9 

SOx 1.6 1.6 1.6 1.6 1.6 1.6 1.6 

Tons/day – Annual Average 

NOx 26.3 25.6 25.1 24.5 24.0 23.4 22.8 

PM2.5 1.5 1.4 1.3 1.3 1.3 1.2 1.2 

SOx 2.2 2.2 2.2 2.2 2.2 2.2 2.2 

C. Number of ICEs 

Based on available information from the District’s Permit database, the number of ICEs 

that have Permits to Operate (PTO), finalized Authority to Construct (ATC), or 

registered under the Permit Exempt Registration (PEER) program is shown below. It is 

important to mention that industries within the District, both agriculture and nonagriculture, have replaced hundreds of their engines with electric motors over the past 

several years which have resulted in significant emissions reductions. The District is 

continuing to improve the accuracy of the inventory of ICEs used in agricultural 

operations. As previously mentioned, the proposed changes to Rule 4702 would only 
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apply to approximately 598 permitted Non-AO spark-ignited engines that are not 

emergency or low-use engines. 

 

Table 3: Number of Engines in SJVAB

Category Active PTO + Finalized ATCs PEER 

Non-AO Spark-Ignited Rich-Burn 453 

Non-AO Spark-Ignited Lean-Burn 102 

Non-AO Spark-Ignited Rich-Burn 

Cyclic loaded Field Gas-Fired 

43 

Non-AO Spark-Ignited Rich-Burn 

Waste Gas 

4 

Non-AO Non-Emergency 

Compression-Ignited 

305 

All Low-Use 30 

All Spark-Ignited Emergency 684 

All Compression-Ignited Emergency 3516 

AO Spark-Ignited (Irrigation pumps) 290 79 

AO Compression-Ignited (Irrigation 

pumps) 

1764 30 

TOTAL 7191 109 

V. DISCUSSION 

A. Existing Rule 4702 - Phase 2 

Rule 4702 was adopted in August 2003 and was subsequently amended in June 2005, 

April 2006, and January 2007. The purpose of Rule 4702 is to limit NOx, CO, and VOC 

emissions from stationary internal combustion engines. The rule applies to any 

stationary internal combustion engine with a rated brake horsepower (bhp) greater than 

50. In November 2001, ARB published a guidance document “Determination of 

Reasonably Available Control Technology (RACT)/Best Available Retrofit Control 

Technology (BARCT) for Stationary Spark-Ignited Internal Combustion Engines”, which 

presents the technologies for controlling NOx, CO, and VOC from spark-ignited ICEs 

and the recommended RACT and BARCT emission standards in order to assist air 

districts in developing their own regulations. The current emission limits in Rule 4702 

for spark-ignited ICEs are consistent with the recommended emission standards in 

ARB’s BARCT determination guidance document. The emission limits in Rule 4702 for 

compression-ignited engines are consistent with EPA’s emission standards established 

in the “Control of Emissions of Air Pollution from Nonroad Diesel Engines and Fuel” 

published by EPA in the Federal Register on October 23, 1998 and June 29, 2004. 

Rule 4702 provides some exemptions from the emissions standards or other 

requirements of the rule for engines used in certain specific applications, such as an 

emergency standby engine, military tactical equipment, and certain types of engines 

used in agricultural operations (e.g., wind machines, mobile agricultural equipment, 
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engines used to propel implements of husbandry). Rule 4702 exempts engines from 

complying with the emission limits provided they do not exceed 200 hours of operation 

per calendar year and meet other conditions. 

In addition to complying with the emission limits, operators are required to comply with 

the provisions for monitoring, emission control plan, recordkeeping, periodic compliance 

testing, and an option to comply with the requirements of the Alternative Emission 

Control Plan (AECP) in lieu of having each engine comply with the emission limits. 

The existing NOx emission limits in Rule 4702 are shown in below. The VOC and CO 

limits are 250/750 ppmv and 2,000 ppmv, corrected to 15% O2, respectively. 

Table 4: Rule 4702 Existing NOx Limits 

Spark-Ignited Engines NOx Limit (ppmv corrected to 15% O2) 

1. Rich-Burn (Non-AO) 

 a. Waste gas fuel 50 ppmv or 90% reduction 

 b. Cyclic loaded, field gas 50 ppmv 

 c. All other engines 25 ppmv or 96% reduction 

2. Lean-Burn (Non-AO) 

 a. Two stroke, gaseous fuel less than 100 

bhp 

75 ppmv or 85% reduction 

 b. All other engines 65 ppmv or 90% reduction 

3. Rich-Burn AO engines 90 ppmv or 80% reduction (Comply by 1/1/09 

or, if owner has an agreement to electrify, 

comply by 1/1/10).

4. Lean-Burn AO engines 150 ppmv or 70% reduction (Comply by 1/1/09 

or, if owner has an agreement to electrify 

comply by 1/1/10).

5. Certified Spark-Ignited AO engines Meet certified spark ignited standard HC + 

NOx <0.6 g/bhp-hr (Comply by 6/1/06).

Compression-Ignited Engines Emission Limit/Standard

1. Non-certified Compression-Ignited Engines 

 a. >50 to 500 bhp EPA Tier 3 or Tier 4 (Comply by 1/1/10).

 b. >500 to 750 bhp and less than 1000 

annual operating hours 

EPA Tier 3 (Comply by 1/1/10).

 c. >750 and less than 1000 annual 

operating hours 

EPA Tier 4 (Comply by 7/1/11).

 d. >500 bhp and equal to or greater than 

1000 annual operating hours 

80 ppmv NOx (Comply by 1/1/08, or, if there is 

an agreement to electrify, comply by 1/1/2010).

2. Certified Compression-Ignited Engines 

 a. EPA certified Tier 1 or Tier 2 engines EPA Tier 4 (Comply by1/1/2015 or 12 yrs after 

installation date, whichever is later).

 b. EPA Certified Tier 3 or Tier 4 engines Meet certified compression ignited engine 

standard in effect at the time of installation 

(Comply at the time of installation). 
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Draft Staff Report: Rule 4702 September 9, 2010 

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B. Other Air Districts’ Stationary Internal Combustion Engine (ICE) Rules 

District staff reviewed the engine rules of other California air districts as well as the ARB 

Determination of RACT/BARCT for Stationary Spark-Ignited Internal Combustion 

Engines, and found that South Coast Air Quality Management District (SCAQMD) Rule 

1110.2 (Emissions from Gaseous- and Liquid-Fueled Internal Combustion Engines) has 

the most stringent regulatory emission limits. Currently, no air district rules regulate 

stationary ICEs rated less than 50 bhp. As previously mentioned, the current limits in 

existing Rule 4702 are consistent with the limits in the ARB RACT/BARCT document, 

but are less stringent than SCAQMD Rule 1110.2. 

SCAQMD Rule 1110.2 (Emissions from Gaseous- and Liquid-Fueled Internal 

Combustion Engines) 

SCAQMD Rule 1110.2, which was amended in February 2008, applies to all stationary 

and portable engines over 50 bhp. The rule requires operators to remove stationary 

engines from service, or replace the engines with electric motors, or not operate the 

engines in a manner that exceed the limits indicated below. For further details on 

emission requirements, please refer to Rule 1110.2 which is available for download at 

SCAQMD website at www.aqmd.gov. 

Table 5: Rule 1110.2 Emission Limits for Stationary Non-Biogas Engines

Pollutant Current Limit (ppmvd) Effective 7/1/2010 (ppmvd) Effective 

7/1/2011 

(ppmvd) 

 bhp≥500 bhp>50<500 bhp≥500 bhp>50<500 All 

NOx 36 45 11 45 11 

VOC 250 250 30 250 30 

CO 2000 2000 250 2000 250 

Table 6 – Emission Limits for Stationary Biogas Engines

Concentration limits until June 30, 2012 

NOx (ppmvd) VOC (ppmvd) CO (ppmvd) 

bhp ≥ 500: 36 x ECF1

bhp < 500: 45 x ECF1

Landfill Gas: 250 

Digestor: 250 x ECF1

2000 

Concentration Limits on and after July 1, 20122

NOx: 11 ppmvd VOC: 30 ppmvd CO: 250 ppmvd 

1

ECF (Efficiency Correction Factor) = (9250 Btu/hp-hr)÷Measured qa in Btus/hp-hr. Measured qa shall be 

based on the lower heating value of the fuel. ECF shall not be less than 1. 

2Concentration limits on and after July 1, 2012 shall become effective provided SCAQMD conducts a 

technology assessment that confirms that the limits are achievable and reports to the Board by July 2010. 

According to SCAQMD staff, the technology assessment is underway and will probably be completed in 

2011. 
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Draft Staff Report: Rule 4702 September 9, 2010 

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Table 7: SCAQMD Rule 1110.2 Emission Limits for New NonEmergency Electrical Generation Engines

 Emission Standard (lb/MW-hr) 

NOx 0.070 

CO 0.20 

VOC 0.10 

C. EPA Regulations for Stationary Internal Combustion Engines 

In addition to evaluating other air districts’ stationary ICE rules, District staff also 

reviewed EPA’s New Source Performance Standards (NSPS) and National Emission 

Standards for Hazardous Air Pollutants (NESHAP) that apply to this source category. It 

is important to mention that sources subject to the NSPS and the NESHAP are required 

to comply with those requirements in addition to the requirements of Rule 4702. 

Spark-Ignited Engines 

The NSPS requirements for stationary spark-ignition ICEs are specified in 40 CFR Part 

60 Subpart JJJJ. District staff has determined that the existing emission limits of Rule 

4702 are more stringent than the NSPS limits. For example, the NSPS emission limit 

for spark-ignited rich-burn engines rated at greater than 50 bhp is 2.0 g/bhp-hr of 

HC+NOx is less stringent than the current Rule 4702 NOx limit of 25 ppmv (corrected to 

15% O2 on a dry basis) for spark-ignited rich-burn engines. Spark-ignited engines rated 

between 25 to 50 bhp are already subject to the NSPS emission standards specified in 

40 CFR 60 Subpart JJJJ (Standards of Performance for Stationary Spark Ignition 

Internal Combustion Engines). This NSPS became effective on March 18, 2008 and 

applies to new, modified, and reconstructed SI ICE regardless of the size and 

combusting any fuel. Emissions are controlled to levels achievable by Best 

Demonstrated Technology. The regulated pollutants are NOx, CO, and VOC. The 

HC+NOx emission limits in the NSPS for SI ICEs 25 to 50 bhp range from 2.0 to 2.8 

g/hp-hr, depending on the type of engine and fuel used. 

The NSPS requirements for stationary compression-ignition ICEs are specified in 40 

CFR Part 60 Subpart IIII. The current emission standards of Rule 4702 for 

compression-ignited engines rated greater than 50 bhp are consistent with the NSPS. 

Compression-ignited engines rated between 25 to 50 bhp are already subject to the 

NSPS emission standards specified in 40 CFR 40 Subpart IIII ( Standards of 

Performance for Stationary Compression Ignition Internal Combustion Engines). This 

NSPS became effective on July 11, 2006, and it establishes requirements for 

manufacturers, owners, and operators of new engines whose construction, modification, 

or reconstruction began after July 11, 2005. The NSPS requires the on-engine controls, 

after treatment, and low sulfur fuel to achieve the same standards as required for 

nonroad engines. The regulated pollutants are NOx, NMHC (VOC), CO, and particulate 

matter (PM). Depending on the engine size, model year, use (fire pump or non-fire 

pump engines, and emergency or non-emergency), the emission standards in the 
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NSPS range from 3.0 to 7.8 g/hp-hr of NMHC+NOx, 3.7 to 4.1 g/hp-hr of CO, and 0.02 

to 0.6 g/hp-hr of PM. 

The NESHAP requirements for stationary reciprocating ICEs are specified in 40 CFR 

Part 63 Subpart ZZZZ. The NESHAP regulates certain polycyclic aromatic 

hydrocarbons (PAHs). Rule 4702 establish emission limits for volatile organic 

compounds (VOCs), which may not necessarily be PAHs. Therefore, the NESHAP 

standards cannot be compared to the VOC limits of Rule 4702. Copies of the NSPS 

and the NESHAP can be downloaded from the website at 

http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr. 

VI. DRAFT AMENDMENTS TO RULE 4702 

District staff considered comments provided by EPA and stakeholders at the June 24, 

2010 Scoping Meeting in developing the draft amendments to Rule 4702. A summary 

of the written comments and District staff’s responses are discussed in Appendix A of 

the Draft Staff Report. The draft amendments to Rule 4702 are discussed below. 

Section 1.0 Purpose 

The purpose of the existing rule is to limit the emissions of nitrogen oxides (NOx) 

carbon monoxide (CO) and volatile organic compounds (VOC). This section would be 

modified to include limiting the emissions of sulfur dioxide (SOx) from internal 

combustion engines. 

Section 2.0 Applicability 

Currently, Rule 4702 does not apply to stationary ICEs rated at 50 brake horsepower 

(bhp) or less. District staff is proposing to change the applicability of the rule so it would 

to also apply to small stationary ICEs rated at 25 to 50 bhp. 

Section 3.0 Definitions 

• The existing rule defines “Agricultural Operations” by referencing it to the definition in 

Rule 4550 (Conservation Management Practices). For clarity the definition of 

“Agricultural Operation” will be included in Rule 4702 instead of referring it to another 

rule. 

• A definition of Air Pollution Control Officer (APCO) would be added for clarity of the 

rule. 

• A definition of California Reformulated Diesel would be included in the rule since the 

one of the SOx control requirement being proposed is the use of this fuel type. 

• A definition of Higher Heating Value would be added for clarity of the rule. 
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• A definition of Low-use Engine would be included in the rule. The existing provisions 

of Section 4.2.2 would be deleted and then transferred into the definition of Low-use 

Engine. 

• The existing definition of Public Utilities Commission (PUC) Quality Natural Gas 

would be modified for consistency with the definition in Rule 4320 (Advanced 

Emission Reduction Options for Boilers, Steam Generators, and Process Heaters 

Greater than 5 MMBu/hr). 

Section 4.0 Exemption 

Section 4.2.2 would be modified to state that a “low-use engine” as defined in Section 

3.0 is exempt from the rule. The existing conditions for exempting for this type of 

engine that are currently specified in Section 4.2.2 would deleted, but they would be 

relocated in the definition of “low-use engine” in Section 3.0. 

Section 4.4 allows an exemption from the requirements of Best Available Control 

Technology (BACT) and Offset requirements of Rule 2201 (New and Modified 

Stationary Source Review Rule) if the replacement engine is installed for the sole 

purpose of complying with Rule 4702. District staff is proposing to delete Section 4.4 

because in the past EPA has disapproved for inclusion into the State Implementation 

Plan (SIP) District’s prohibitory rules which included a similar exemption. EPA has 

stated in previous rulemaking projects that BACT and Offset requirements should be 

addressed in Rule 2201 instead of the prohibitory rule. It should be mentioned that Rule 

2201 Sections 4.2.3 and 4.6.8 provides an exemption from BACT and Offset 

requirements for existing facilities that installs or modifies an emission control technique 

solely for the purpose of compliance with the requirements of District, State, or Federal 

air pollution control laws provided the conditions specified in Rule 2201 are met. 

Section 5.0 Requirements 

• New Section 5.1 

This section would establish the requirements for spark-ignited engines and 

compression-ignited engines rated at 25 to 50 brake horsepower (bhp) that are used 

exclusively in Non-AO. These small engines are already regulated under the existing 

federal Standards of Performance. The provision would prohibit a person from 

supplying, selling, offering for sale, soliciting the operation, or installing engines rated at 

25 to 50 bhp horsepower unless the engines meet the applicable requirements and 

emission limits specified in 40 Code of Federal Regulation (CFR) 60 Subpart IIII 

(Standards of Performance for Stationary Compression Ignition Internal Combustion 

Engines) and 40 CFR 60 Subpart JJJJ (Standards of Performance for Stationary Spark 

Ignition Internal Combustion Engines) for the year that the engine is purchased.

Estimated Number of Small ICEs 

In 2008, District staff conducted a survey of non-agricultural operations (Non-AO) 

permitted sources in the District to determine the number of small engines rated at 25 to 

50 bhp. Data from the survey indicated that there are approximately 750 small engines. 
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Draft Staff Report: Rule 4702 September 9, 2010 

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Some of these small engines may already be subject to the federal Standards of 

Performance depending on the model, year of manufacture, fuel type, and engine 

usage/application. District staff would like to improve the emission inventory on small 

engines and is proposing to require owners of Non-AO small engines in the District to 

submit a report to the District. The District is not requiring owners of small engines 

used AO to submit a report at this time because the District has determined, based on 

information gathered by the District’s Compliance Division, that there is an insignificant 

number of AO small engines. Engines that are rated at 25 to 50 bhp are too small for 

most farm water pumping, transfer, or booster pump purposes, therefore not typically 

used in AO. 

Therefore, the owner of a Non-AO engine rated 25 to 50 bhp would be required to 

submit a report to the District which includes information on the number of small 

engines at a stationary source, location of each engine, engine manufacturer, model 

designation and engine serial number, engine bhp, fuel type and consumption rate, 

ignition type and combustion type, purpose of the engine, and daily operating schedule. 

This is a one-time reporting requirement to allow the District to improve the emission 

inventory for this category. 

• Section 5.2 

This section would restructure the existing the emission limits/standards for Non-AO 

and AO spark-ignited engines and compression-ignited engines greater than 50 bhp. 

This section would also specify the proposed limits for Non-AO spark-ignited engines 

greater than 50 bhp. The following are the sections being modified as well as the new 

provisions being proposed: 

o Section 5.2.1 would indicate that Table 1 emission limits are engines used in 

non-agricultural operations (Non-AO). The existing emission limits for sparkignited engines used in AO would be removed from existing Table 1 and would 

be relocated in new Table 3. Table 1 limits would effective until December 31, 

2013. 

o New Section 5.2.2 would establish the proposed emission limits for Non-AO 

spark-ignited engines greater than 50 bhp as shown below. The emission limits 

for Non-AO spark-ignited engines, except waste gas fueled engines and cyclicloaded field gas fueled engines, are 11 ppmv NOx, 500 ppmv CO, and 30 ppmv 

VOC. The 11 ppmv NOx limit is consistent with SCAQMD Rule 1110.2. For cyclicloaded field gas fueled engines, the limits are 25 ppmv NOx, 500 ppmv CO, and 30 

ppmv VOC. The existing emission limits for waste gas fueled spark-ignited 

engines would remain the same as indicated in existing Table 1 of the draft rule. 

o New Section 5.2.2.1 would indicate that the owner of Non-AO spark-ignited 

engines may comply with the proposed emission limits or pay annual NOx 

emission fees as specified in new Section 5.2.2.2 and new Section 5.6. 
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Draft Staff Report: Rule 4702 September 9, 2010 

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o New Section 5.2.2.2 would indicate that in lieu of complying with the proposed 

emission limits, the owner of Non-AO engine may elect to pay annual NOx 

emission fees and comply with the proposed SOx control and monitoring 

requirements. 

Table 8: Proposed Emission Limits for Non-AO Spark-ignited Engines 

Effective on and after January 1, 2014. 

All ppmv limits are corrected to 15% O2 on a dry basis. 

Engine Type NOx Limit CO Limit VOC Limit 

All Spark-ignited 

Engines, Except 

Waste Gas Fueled 

and Cyclic Loaded 

Field Gas Fueled 

Engines 

11 ppmv 500 ppmv 30 ppmv 

Waste Gas Fueled 

Engines 

50 ppmv or 90 

percent reduction 

2000 ppmv 250 ppmv 

Cyclic Loaded, Field 

Gas Fueled Engines 

25 ppmv 500 ppmv 30 ppmv 

• District staff is proposing to delete the existing category for spark-ignited lean-burn 

two-stroke, gaseous fueled, less than 100 horsepower engine for consistency with 

the SCAQMD Rule 1110.2. The SCAQMD Rule 1110.2 NOx limit of 11 ppmv 

effective July 1, 2011 applies to non-biogas engines regardless of the size or the 

type of engines. In addition, the District is not aware of any two-stroke lean burn 

spark-ignited engines less than 100 horsepower currently operating within the San 

Joaquin Valley. 

• Section 5.2.3

The existing emission limits for AO spark-ignited engines that are part of existing Table 

1 would be relocated to new Table 3. There are no changes to the existing limits for 

Non-AO emission limits. 

• New Section 5.2.4

The existing requirements for compression-ignited engines currently specified in Section 

5.1.2 would be relocated to new Section 5.2.4. Also, the existing Table 2 (compressionignited engine emission limits/standards) would be renumbered as Table 4. No change 

to the existing emission limits/standards are being proposed for compression-ignited 

engines since they are technologically the most stringent standards. 

• New Section 5.6 

This section would establish a compliance option to pay annual fees in lieu of complying 

with the proposed emission NOx limit for Non-AO spark ignited engines. The provision 

would include the method for calculating the total annual NOx emissions and the annual 

fee payments for engines that would comply under this compliance option. This fee 
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Draft Staff Report: Rule 4702 September 9, 2010 

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provision is similar to that found in District Rule 4320 (Advanced Emissions Reduction 

Option for Boilers, Steam Generators, and Process Heaters – Greater than 5.0 

MMBtu/hr). 

• New Section 5.7 

This section would specify the sulfur dioxide (SOx) control requirements for non-AO 

spark-ignited engines and non-AO compression-ignited engines greater than 50 bhp. 

The owner would be required to comply with one of the following: 

o Fire the engine exclusively on PUC-quality natural gas, commercial propane, 

butane, or liquefied petroleum gas or a combination of such gases. 

o Use California Reformulated gasoline for gasoline fueled engines. 

o Use California Reformulated Diesel for all compression-ignited engines. 

o Limit the sulfur content of gaseous fuel to no more than 5 grains of total sulfur per 

100 standard cubic feet. 

o Fire the engine on liquid fuel that contains no more than 15 ppm sulfur. 

o Install and properly operate an emission control system that reduces SO2

emissions by at least 95% by weight. 

• Renumbered Section 5.8.9 (previously Section 5.6.9) Portable NOx Analyzer 

Monitoring requirement for Non-AO Spark-Ignited Engines 

This existing section requires the owners of Non-AO spark-ignited engines to take NOx 

emission readings with a portable NOx analyzer to verify compliance with the emission 

requirements during each calendar quarter in which a source test is not performed and 

the engine is operated. This section would be modified to allow owners of engines that 

operate less than 120 calendar days per calendar year to take one NOx emission 

reading during that period in which a source test is not performed and the engine is 

operated. This change is in response to stakeholders’ recommendation for portable 

NOx monitoring requirement for engines that only operate a few months of the year. It 

would reduce unnecessary testing for engines which may only operate a few days in a 

given month. Such short term operation is not expected to be significantly different than 

the emissions from a previously tested quarter and therefore does not warrant additional 

testing. 

• Existing Section 5.6.11 

This section requires a nonresettable fuel meter or an APCO- approved alternative 

device for each engine that is subject to the Alternate Emission Control Plan (AECP). 

Section 5.6.11 would be deleted since District staff is also proposing to delete the AECP 

provision because no engine owner is currently using the AECP compliance option. 

• New Section 5.10 SOx Emissions Monitoring Requirements 

This section would require the owners of Non-AO spark-ignited engines or Non-AO 

compression-ignited engines to perform an annual fuel analysis if owner elects to 

comply with either the fuel sulfur content limit of 5 grains per 100 standard cubic feet or 

15 ppmv sulfur. Engines fired exclusively on PUC-quality natural gas, commercial 

propane, butane, liquefied petroleum gas, or a combination of such gases, as well as 
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Draft Staff Report: Rule 4702 September 9, 2010 

15

California reformulated gasoline or California reformulated diesel would not require 

annual fuel analysis, since such analysis is routinely provided by the supplier. 

The owner of an engine who elects to install and operate a SOx control device in order 

to comply with new Section 5.7.6 would need to submit the key operating parameters 

and frequency of monitoring and recording for approval by the District. Engines 

equipped with a SOx control device would need to be source tested annually to 

demonstrate compliance with 95% SOx reduction efficiency. 

 

• New Section 6.4.6 

This section would specify the test methods for determining oxides of sulfur, total sulfur 

as hydrogen sulfide, sulfur content of liquid fuel, and calculation method for SOx control 

efficiency. 

• Existing Sections 7.5.2.3, 7.5.2.3.1, and 7.5.2.3.2

This sections indicates that requirements of Rule 4701 (Internal Combustion Engines - 

Phase 1) shall no longer apply to engines that are in full compliance with the existing 

requirements of current Rule 4702. This section would be deleted because it serves no 

useful purpose since all spark-ignited engines that were previously subject to Rule 4701 

are already in full compliance with existing Rule 4702. Rule 4701 does not regulate 

compression-ignited. 

 

• New Section 7.7 

This section would require the owner of a Non-AO spark-ignited engine to submit to the 

an Emission Control Plan, an Inspection and Maintenance Plan, and a completed 

application for an Authority-to-Construct no later than July 1, 2013. By January 1, 2014, 

the owner shall demonstrate full compliance with Table 2 emission limits. On and after 

January 1, 2014 operate the engine in such a manner that complies with the applicable 

requirements of the Rule 4702. 

• New Section 7.8 

The owner of a Non-AO spark-ignited engine who elects to pay annual NOx emission 

fees to the District in lieu of complying with the proposed emission limits would be 

required to submit an Emission Control Plan which includes the information specified in 

new Section 7.8.1. The owner would be required to pay the total annual fee to the District 

no later than July 1 of each year for the emissions of the previous calendar year. The first 

payment would be due no later than July 1, 2014. Payment would continue annually until 

the engine either is permanently removed from use in the San Joaquin Valley Air Basin 

and the Permit to Operate is surrendered, or the operator demonstrates compliance with 

then proposed Table 2 emission limits. 

 

• Existing Section 8.0 

Section 8.0 allows an owner to comply with the existing emission requirements of the rule 

for a group of engines through the use of the Alternative Emission Control Plan (AECP) 

instead of each engine individually complying with the emission limit. This section would 

be deleted because no owner is using the AECP. 
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Draft Staff Report: Rule 4702 September 9, 2010 

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VII. CATEGORIES OF ENGINES WHERE NO RULE CHANGES ARE BEING 

PROPOSED 

District staff is not proposing any changes to the emission limits and standards for the 

following categories of engines: 

1. Non-AO Waste Gas Fueled Spark Ignited Rich-Burn Engines 

The current NOx limit in Rule 4702 for Non-AO waste gas fueled rich-burn engines is 50 

ppmv (at 15% O2) or 90 percent reduction. Although SCAQMD Rule 1110.2 specifies a 

NOx limit of 11 ppmv for landfill gas or digester gas fired engines effective July 1, 2012, 

Rule 1110.2 includes a provision to complete a technology assessment by July 2010 

and that the limit will only be implemented if the result of SCAQMD’s technology 

assessment that is confirms that 11 ppmv is indeed achievable. In a recent telephone 

conversation with SCAQMD staff, District staff has found that the technology 

assessment would not be completed until next year. Therefore, District staff is not 

proposing any change to the current limit for Non-AO waste gas fueled rich-burn 

engines until such time that SCAQMD’s technology assessment confirms that it is 

technologically and economically feasible to achieve their rule limit. 

2. Emergency Engines and Low-Use Engines 

District staff is not proposing any changes to the exemption requirements for emergency 

engines and low-use engines. The existing requirements are consistent with ARB 

RACT/BARCT Determination for Spark-Ignited Engines and ARB Air Toxics Control 

Measures (ATCM). In addition, the ATCM is already being implemented through the 

District’s process for issuing Permits to Operate. 

3. Agricultural Spark-Ignited Engines 

The current limits in existing Rule 4702 for agricultural spark-ignited engines are 90 

ppmv corrected to15% O2 (equivalent to 1.26 grams/hp-hr) or 80% reduction for richburn engines, 150 ppmv corrected to 15% O2 (equivalent to 2.1 grams/hp-hr) or 70% 

reduction for lean-burn engines, and less than 0.6 grams/brake horsepower-hour 

(g/bhp-hr) for certified spark-ignited engines. District staff is not proposing any changes 

to the existing emission limits for spark-ignited engines used in agricultural operations 

because the current limits have been recently implemented in January 2009. Thus, the 

operators have not yet realized the economic benefits from the investment they made in 

retrofitting/replacing their older engines to comply with the rule limits. 

EPA commented that the District should provide further analysis of whether more 

stringent limits for AO engines are appropriate and if the standard qualifies as 

Reasonably Available Control Technology (RACT). 

District staff believes that the existing Rule 4702 emission limits for agricultural engines 

meets Reasonably Available Control Technology (RACT). In August 2007, EPA 
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Draft Staff Report: Rule 4702 September 9, 2010 

17

published the Technical Support Document (TSD)1 for the current version of Rule 4702 

in conjunction with EPA’s full approval of the rule for inclusion into the State 

Implementation Plan (SIP). The TSD basically stated that SJVUAPD provided 

documentation for the process of determining BACM/BACT2

 and in the staff report, 

provided analyses of the inventory of affected engines and the technological and 

economic feasibility of possible control technologies. The TSD also stated that EPA 

concurs with the BACM/BACT analysis, and noted that the emission limits and other 

provisions in submitted Rule 4702 are quite stringent when compared with the 

Determination and comparable rules in other air districts, and in light of the economic 

and social circumstances in the San Joaquin Valley. District staff believes that the 

existing emission standards for AO spark-ignited engines in current Rule 4702 still 

meets RACT even though it they were established three years ago because the current 

economic downturn in the San Joaquin Valley’s agriculture makes it more economically 

infeasible to require lower emission limits for AO engines. 

4. Compression-Ignited (Diesel) Engines 

The existing emission limits for compression-ignited engines apply to both nonagricultural and agricultural engines. District staff is not considering any changes to the 

existing NOx limits in Rule 4702 which requires EPA certified Tier 3 or Tier 4 diesel 

engines or meet 80 ppmv NOx, depending on the size of the engine and whether the 

diesel engine is non-certified or certified. It should be noted that certified Tier 1 or Tier 2 

diesel engines are required to comply with EPA certified Tier 4 by January 1, 2015 or 12 

years after installation date, whichever is later. Non-certified diesel engines that are 

required to meet either Tier 3 or Tier 4 depending on the engine size and its operating 

hours have just began complying with the existing emission limits early this year, and 

some of the larger engines will need to comply by mid-2011. Engines greater than 500 

hp that operate at least 1,000 hours annually were required to meet 80 ppmv NOx last 

January 1, 2008 or by January 1, 2010, if the owner has an agreement to replace the 

diesel engine with electric motor. 

IX. CONTROL TECHNOLOGIES FOR SPARK-IGNITED ENGINES 

The control techniques for reducing NOx emissions from spark-ignited engines includes 

air/fuel adjustment, ignition timing retard, air/fuel adjustment plus ignition timing retard, 

prestratified charge, nonselective catalytic reduction, selective catalytic reduction, and 

low emission combustion. The likely control technologies that would be used to achieve 

the lower NOx limits being considered in the draft amendments to Rule 4702 are 

nonselective catalytic reduction for spark-ignited rich-burn engines and selective 

catalytic reduction for lean-burn spark-ignited engines. Oxidation catalyst is the control 

technology that can achieve lower VOC emissions from spark ignited engines. The 

 

1

 Technical Support Document for EPA’s Notice of Proposed Rulemaking and Direct Final Rule for the 

California State Implementation Plan – San Joaquin valley Unified air Pollution Control District Rule 4702 

(Internal Combustion Engine – Phase 2), August 2007. 

2

 The TSD stated that BACM includes BACT in the same way as RACM includes RACT. 
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Draft Staff Report: Rule 4702 September 9, 2010 

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applicability of these control techniques on the type of spark-ignited engines are 

discussed below. 

Air/Fuel Adjustment 

Adjusting the air/fuel toward fuel-rich operation reduces the amount of oxygen available 

to combine with nitrogen, which inhibits NOx formation. The low oxygen environment 

also contributes to incomplete combustion, which results in lower combustion 

temperature, which lowers NOx formation rate. However, the incomplete combustion 

increases CO emissions and hydrocarbon emissions. The combustion efficiency is also 

reduced, which increases fuel consumption. Excessively rich A/F may result in 

combustion instability and unacceptable increases in CO emissions. Sustained NOx 

reduction with changes in ambient conditions and engine load is best accompanied by 

installing an automatic A/F control system. The achievable NOx emissions reduction 

ranges from 10 to 40 percent from uncontrolled levels. 

Ignition Timing Retard 

Ignition timing retard delays initiation of combustion to later in the power cycle, which 

increases the volume of the combustion chamber and reduces the residence time of the 

combustion process. This increased volume and reduced residence time offers the 

potential for reduced NOx formation. The extent to which the ignition timing can be 

retarded to reduce NOx emissions varies for each engine, as ignition timing retard 

increases exhaust temperature, which may adversely impact valve life and turbocharger 

performance, and extreme levels of timing retard may result in combustion instability 

and loss of power. Sustained NOx reduction with changes in ambient conditions and 

engine load is best accompanied by installing an electronic ignition control system. The 

achievable NOx reduction of ignition timing retard can be as high as 40 percent. 

Air/Fuel (A/F) Adjustment Plus Ignition Timing Retard (IR) 

The combination of A/F and IR can be used to reduce NOx emissions. The achievable 

NOx reduction for the combination of these control techniques is about the same as for 

A/F alone (10 to 40 percent reduction) but offers some flexibility in achieving these 

reductions. Since the parametric adjustments affect such operating characteristics as 

fuel consumption, response to load changes, and other emissions especially CO, the 

combination of A/F and IR offers the potential to reduce NOx while minimizing the 

impact on other operating parameters. 

Prestratified Charge (PSC) 

Prestratified charge combustion is a retrofit system that is limited to 4-stroke carbureted 

natural gas engines. In this system, controlled amounts of air are introduced into the 

intake manifold in a specified sequence and quantity to create a fuel-rich and fuel-lean 

zone. This stratification provides both a fuel-rich ignition zone and rapid flame cooling in 

the fuel-lean zone, resulting in reduced formation of NOx. PSC can achieve about 87 

percent NOx reduction. 
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Draft Staff Report: Rule 4702 September 9, 2010 

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Nonselective Catalytic Reduction (NSCR) 

This technique uses the residual hydrocarbons and CO in the rich-burn engine exhaust 

as a reducing agent for NOx. In an NSCR system, hydrocarbons and CO are oxidized 

by O2 and NOx. The excess hydrocarbons, CO, and NOx pass over a catalyst (usually 

a noble metal such as platinum, rhodium, or palladium) that oxidizes the excess 

hydrocarbons and CO to H2O and CO2, while reducing NOx to N2. 

NOx reduction efficiencies are usually greater than 90 percent, while CO reduction 

efficiencies are approximately 90 percent. The NSCR technique is effectively limited to 

engines with normal exhaust oxygen levels of 4 percent or less. This includes 4-stroke 

rich-burn naturally aspirated engines and some 4-stroke rich-burn turbocharged 

engines. Engines operating with NSCR require tight air-to-fuel control to maintain 

high reduction effectiveness without high hydrocarbon emissions. To achieve effective 

NOx reduction performance, the engine may need to be run with a richer fuel 

adjustment than normal. This exhaust excess oxygen level would probably be closer to 

1 percent. Lean-burn engines could not be retrofitted with NSCR control because of the 

reduced exhaust temperatures. 

Selective Catalytic Reduction 

Selective catalytic reduction is a postcombustion technology that has been shown to be 

effective in reducing NOx in exhaust from lean-burn engines. An SCR system consists 

of an ammonia storage, feed, and injection system, and a catalyst and catalyst housing. 

Selective catalytic reduction systems selectively reduce NOx emissions by injecting 

ammonia (either in the form of liquid anhydrous ammonia or aqueous ammonium 

hydroxide) into the exhaust gas stream upstream of the catalyst. Nitrogen oxides, 

NH3, and O2 react on the surface of the catalyst to form N2 and H2O. For the SCR 

system to operate properly, the exhaust gas must be within a particular temperature 

range (typically between 450 and 8500

F). The temperature range is dictated by the 

catalyst (typically made from noble metals, base metal oxides such as vanadium and 

titanium, and zeolite-based material). According to a report published by Manufacturers 

of Emission Control Association3

, “base metal catalysts, typically vanadium and 

titanium, are used for exhaust gas temperatures between 4500F and 8000F. For higher 

temperatures (6750

F to 11000F), zeolite catalyst may be used. Precious metal SCR 

catalysts are useful for low temperatures (3300F to 5500F).” Exhaust gas temperatures 

greater than the upper limit will pass the NOx and ammonia unreacted through the 

catalyst. Ammonia emissions, called NH3 slip, are a key consideration when specifying 

a SCR system. 

SCR is most suitable for lean-burn engines operated at constant loads, and can achieve 

efficiencies as high as 90%. For engines which typically operate at variable loads, such 

as engines on gas transmission pipelines, an SCR system may not function effectively, 

causing either periods of ammonia slip or insufficient ammonia to 

gain the reductions needed. 

 

3

 “Emission Control Technology for Stationary Internal Combustion Engines”, published by the 

Manufaturers of Emission Controls Association, July 1997. 
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Draft Staff Report: Rule 4702 September 9, 2010 

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Catalytic Oxidation 

Catalytic oxidation is a postcombustion technology that has been applied, in limited 

cases, to oxidize CO in engine exhaust, typically from lean-burn engines. As previously 

mentioned, lean-burn technologies may cause increased CO emissions. The application 

of catalytic oxidation has been shown to be effective in reducing CO emissions from 

lean-burn engines. In a catalytic oxidation system, CO passes over a catalyst, usually a 

noble metal, which oxidizes the CO to CO2 at efficiencies of approximately 70 percent 

for two-stroke lean burn engines and 90 percent for four-stroke lean burn engines. 

X. EMISSION REDUCTION ANALYSIS 

As part of the rule development process, District staff prepared a Preliminary Emission 

Reduction Analysis that would result from lowering the current NOx and VOC emission 

limit. The analysis indicates that the NOx emissions would be reduced by 75% from the 

2014 baseline emission inventory or 7.6 tons per day. The VOC emissions would be 

reduced by 92% from the 2014 baseline emission inventory or 2.6 tons per day. The 

CO emissions would be reduced by 75% from the 2014 baseline emission inventory or 

10.3 tons per day. The emission reduction analysis will be revised when additional 

information becomes available. Please refer to Appendix B for details of the emission 

reduction analysis. 

XI. COST EFFECTIVENESS ANALYSIS 

CH&SC Section 40920.6(a), requires the District to analyze the cost effectiveness of 

new rules or rule amendments that implement Best Available Retrofit Control 

Technology (BARCT) or all feasible measure. District staff prepared a Preliminary Cost 

Effectiveness Analysis based on extrapolation of costs information from the 2001 ARB’s 

Determination of Reasonably Available Control Technology and Best Available Retrofit 

Control Technology for Stationary Spark-Ignited Internal Combustion Engines. 

The analysis indicated the cost effectiveness ranged from about $1,000 to $31,800 per 

ton of NOx for spark-ignited rich-burn ICEs to upgrade existing NSCR control system, 

depending on the engine size and annual operating hours. For spark-ignited lean-burn 

ICEs that would need to upgrade existing SCR control system, the cost effectiveness 

ranged from $1,000 to $22,500 per ton of NOx, depending on the engine size and 

annual operating hours. For lean-burn ICEs rated at 200 to 1,500 brake horsepower 

that might need to install an SCR control system, the cost effectiveness ranged from 

$22,500 to $38,400 per ton of NOx, depending on the engine size and annual operating 

hours. For lean-burn ICEs rated at 50 brake horsepower the cost effectiveness is 

$126,000 per ton of NOx reduced4

. For cyclic loaded field gas rich-burn engines, the 

cost effectiveness to upgrade the existing NSCR control system ranged from $600 to 

$17,800 per ton of NOx, depending on the engine size and operating hours. The 

 

4

 It is important to mention that there are no permitted lean-burn ICEs rated below 330 brake horsepower 

currently operating in the District. 
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Draft Staff Report: Rule 4702 September 9, 2010 

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preliminary cost effectiveness analysis is presented in Appendix C of the Draft Staff 

Report. 

District staff will revise the preliminary cost effectiveness analysis when additional 

information is received from affected source operators, vendors and manufacturers of 

engine emission control system. District staff encourages operators and control 

equipment vendors to provide cost information that would be useful in refining the draft 

rule amendments. 

Furthermore, the District will explore potential funding opportunities to provide monetary 

incentives for the purposes of assisting with the cost of retrofitting non-agricultural 

engines subject to the proposed amendments to Rule 4702. Funding may be provided 

for retrofits that are completed prior to applicable compliance dates as long as the 

retrofits provide cost-effective, surplus emission reductions. Any incentives provided by 

the District would be subject to the requirements and potential limitations applicable to 

the specific funding source. 

 

XII. SOCIOECONOMIC ANALYSIS 

California Health and Safety Code (CH&SC) Section 40728.5(a) requires the District to 

perform an assessment of the socioeconomic impacts of the adoption, amendment, or 

repeal of a rule or regulation that will significantly affect air quality or emission 

limitations. The socioeconomic analysis will be prepared later in the rule development 

process after the draft amendments to Rule 4702 have been refined. 

XIII. ENVIRONMENTAL IMPACT ANALYSIS 

Pursuant to the California Environmental Quality Act (CEQA), District staff will investigate 

any potential environmental impacts of the draft rule amendments to Rule 4702 and will 

recommend appropriate action to the District Governing Board later in the rule 

development process after the draft amendments to Rule 4702 have been refined. 

XIV. GLOBAL CLIMATE CHANGE 

Global Climate Change (GCC), which is now generally accepted by the scientific 

community to be caused by Greenhouse Gases (GHGs), is a widely discussed 

scientific, economic, and political issue in the United States. Briefly stated, GCC is the 

cumulative change in the average weather of the earth that may be measured by 

changes in temperature, precipitation, storms, and wind. GHGs are gases that trap 

heat in the atmosphere. The scientific and policy communities in the State of California 

have collectively concluded that a significant and growing scientific body of evidence 

supports the need for regulating GHG emissions. Worldwide, California is estimated to 
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Draft Staff Report: Rule 4702 September 9, 2010 

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be the 15th largest emitter of carbon dioxide (CARB 2008), and this fact has added to 

the impetus behind California’s leadership in this area. 

California is exercising climate change leadership in two significant efforts: one, the 

passage and implementation of Assembly Bill 32 (AB32), “California Global Warming 

Solutions Act of 2006”, designed to significantly reduce existing GHG emissions in the 

State of California; and two, in the analysis of environmental impacts of new GHG 

emissions related to discretionary project approvals under the California Environmental 

Quality Act (CEQA). This latter effort has been particularly difficult to implement as no 

state or local agency has provided definitive guidance on how to address GHG 

emissions impacts under CEQA. 

Recognizing the dearth of regulatory guidance, the San Joaquin Valley Air Pollution 

Control District’s Governing Board adopted the Climate Change Action Plan (CCAP) in 

August 2008. The CCAP directed the District’s Air Pollution Control Officer to develop 

guidance documents to assist District staff, valley businesses, land–use agencies, and 

other permitting agencies in addressing GHG emissions as part of the CEQA process. 

With the adoption of the District’s policy on Climate Change and Greenhouse Gases 

(GHG), each new rule or rule amendment will evaluate the potential impact on GHG 

later in the rule development process after the draft amendments to Rule 4702 have 

been refined. 

XV. RULE CONSISTENCY ANALYSIS 

Pursuant to CH&SC Section 40272.2, District staff will prepared a rule consistency 

analysis of Rule 4702 later in the rule development process that compares the elements 

of proposed rule amendments with the corresponding elements of other District rules, 

federal regulations and guidelines that apply to the same source category or type of 

equipment. 

 

XVI. REFERENCES 

1. District Rule 4702 (Internal Combustion Engines – Phase 2). Amended on 

January 18, 2007. 

2. SJVUAPCD Draft Feasibility Study Report for Reciprocating Internal Combustion 

Engines. December 31, 2008. 

2. ARB Determination of Reasonably Available Control Technology and Best 

Available Retrofit Control Technology. November 2001. 

3. South Coast Air Quality Management District’s Rule 111.2 (Emissions from 

Gaseous- and Liquid- Fueled Engines). Amended on February 1, 2008. 
SAN JOAQUIN VALLEY AIR POLLUTION CONTROL DISTRICT 

Draft Staff Report: Rule 4702 September 9, 2010 

23

4. South Coast Air Quality Management District’s Draft Final Staff Report for 

Proposed Amended District Rule 111.2 (Emissions from Gaseous- and LiquidFueled Engines). December 2007. 

5. 40 CFR Part 60 Subpart IIII – Standards of Performance for Stationary 

Compression Ignition Internal Combustion Engines. 

6. 40 CFR Part 60 Subpart JJJJ – Standards of Performance for Stationary Spark 

Ignition Internal Combustion Engines. 

7. 40 CFR 63 Subpart ZZZZ – National Emission Standards for Hazardous Air 

Pollutants for Reciprocating Internal Combustion Engines 

 
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