April 26, 2007 89 

5. PROPOSED NEW SIP MEASURES – Descriptions 

Introduction

ARB staff is proposing a comprehensive and far reaching set of new measures to 

achieve emission reductions needed to address California’s most challenging 

ozone and PM2.5 problems. These measures are designed to make maximum 

progress toward the federal 8-hour ozone standard in the South Coast and the 

San Joaquin Valley. The measures include aggressive near-term NOx and SOx 

emission reduction goals, reflecting the nature and scope of the PM2.5 problem 

in these regions. To achieve the emission reductions needed for both ozone and 

PM2.5, the State Strategy proposes new near-term actions that can be 

completed by 2010 or soon thereafter. 

Need for Fleet Modernization 

More than any other air pollution control effort, ARB’s mobile source program has 

moved the State’s nonattainment areas closer to meeting federal air quality 

standards. California has dramatically tightened emission standards for new onroad and off-road mobile sources and fuels. As new engines have become 

cleaner and cleaner, the emissions contribution from older vehicles has been 

growing to the extent that it will soon make up the majority of mobile source 

emissions. For example, by 2014, heavy-duty trucks 14 years or older will 

produce 51 percent of total heavy-duty truck NOx emissions while only traveling 

20 percent of total truck miles. The same holds true for all on-road vehicles 

combined, where vehicles over 14 years old will produce almost 60 percent of 

total NOx emissions by 2014 but just 20 percent of total miles traveled. 

The benefits of in-use control programs are limited by the underlying engine 

technology and controls. As a result, the majority of new measures in the State 

Strategy are “in-use” measures – programs to help clean up or replace older, 

dirtier vehicles and equipment. We simply cannot wait for the natural turnover of 

older vehicles and equipment (1-5 percent annual turnover depending on vehicle 

or equipment type) being replaced with newer, cleaner vehicles. The challenge 

is that these measures have a much more direct impact on businesses and 

individuals in California than do new engine standards that must be met by 

manufacturers. ARB’s fleet rules will affect owners of public and private vehicles 

and equipment that operate in nonattainment areas throughout the State. 

Compliance flexibility has historically been included in ARB regulations – allowing 

the most cost-effective methods to be used by those who must meet emission 

requirements. And while lower-cost add-on control devices can play a role in 

lowering emissions from mobile fleets, more costly engine and vehicle 

replacements will be needed in many cases. This will place a substantial 

financial burden on owners of vehicles and equipment but is necessary in order 

to achieve air quality standards. Increased incentive funds can supplement 

ARB’s regulatory actions and further accelerate air quality progress. It is 

important to recognize that at current funding levels, incentive funds can pay for 
April 26, 2007 90 

only a relatively small portion of the cost for necessary modernization of 

California’s diesel engine fleets. 

The nature of the proposed new measures (enforceable rules) and California’s 

history of supportive financial incentives provide a sound basis for reductions 

from incentive programs to meet federal requirements for SIP approval. 

Accountability for Emission Reductions 

California’s SIP must outline the plan for meeting air quality standards in all of its 

nonattainment areas. ARB staff’s SIP State Strategy proposal for Board 

approval includes an enforceable commitment to achieve the overall goals set. 

The details of each new measure are publicly considered during separate formal 

rulemaking processes. If a particular measure does not ultimately achieve the 

emission reductions estimated in the SIP, the State is still bound to achieve the 

total aggregate emission reduction commitment, whether this is realized through 

additional reductions from other new measures, or from alternative control 

measures or incentive programs. 

Summary of Proposed New SIP Measures

ON-ROAD SOURCES 

Passenger Vehicles 

Improvements and Enhancements to California’s Smog Check Program 

 Low Pressure Evaporative Test. Require low pressure evaporative system 

testing and repair of evaporative system leaks for all vehicles subject to 

Smog Check inspection. 

 More Stringent Cutpoints. Set more stringent pass/fail cutpoints to ensure 

more cars would have more complete and durable repairs. 

 Annual Inspections for Older Vehicles. Inspect older vehicles annually 

rather than every two years. Older vehicles tend to have greater 

deterioration of emission controls, and consequently, higher emissions. 

 Annual Inspections for High Annual Mileage Vehicles. Inspect annually, 

rather than every two years, vehicles that accrue very high mileage on an 

annual basis. High mileage vehicles tend to have greater deterioration of 

emission controls and, consequently, higher emissions. 

 Add Visible Smoke Test. As part of the Smog Check test, include a check 

for visible smoke to identify vehicles with excess particulate matter 

emissions. 
April 26, 2007 91 

 Inspection of Light- and Medium-Duty Diesels. Include light- and 

medium-duty diesel vehicles in the Smog Check program to provide for 

improved maintenance and reduced emissions for this part of the fleet, and 

require the repair of poorly maintained or old emission systems. 

 Inspection of Motorcycles. Include motorcycle inspections as part of Smog 

Check. Studies indicate that motorcycles are subject to high rates of exhaust 

system tampering. 

Expanded Passenger Vehicle Retirement. Increase the number of vehicles 

that are voluntarily retired by implementing a scrappage program for vehicles that 

are off-cycle from their Smog Check inspections. 

Modifications to Reformulated Gasoline Program. Modify California’s 

Reformulated Gasoline Program to offset ROG emissions due to the increased 

use of ethanol. This rulemaking activity is currently underway and is intended to 

fully mitigate the emission increase, which has been incorporated in the current 

emissions inventory. 

Trucks

Cleaner In-Use Heavy-Duty Trucks. This proposed measure is a 

comprehensive in-use diesel truck emissions reduction program that includes a 

fleet modernization rule and an excess emissions program. Fleet modernization 

would focus on overcoming the typically slow rate of heavy-duty truck turnover by 

requiring truck owners to meet specified emission levels through replacing or 

cleaning up the oldest trucks in their fleets, and would also include a program for 

out-of-state trucks. The excess emissions program would target deterioration 

emissions to keep ultra-clean trucks running cleaner longer. 

GOODS MOVEMENT SOURCES 

Ship Auxiliary Engine Cold Ironing and Other Clean Technology. Reduce 

emissions from ships at berth with at-dock technologies such as cold ironing 

(electrical power) and other clean technologies. 

Cleaner Ship Main Engines and Fuel. Further reduce emissions from main 

engines through added retrofits such as selective catalytic reduction. Support 

efforts by ports and appropriate local entities to accelerate use of cleaner ships 

and rebuilt engines through other tools such as lease restrictions. Require ships 

to use low sulfur diesel fuel in main engines when operating within 24 nautical 

miles of shore. 

Port Truck Modernization. Retrofit or replace older heavy-duty diesel trucks 

that service ports. Work with port authorities to prevent adding older trucks to the 

fleet. ARB rulemaking process for this proposed measure has begun in parallel 

with development proposals by the Ports of Los Angles and Long Beach. 
April 26, 2007 92 

Accelerated Introduction of Cleaner Line-Haul Locomotives. Replace 

existing locomotive engines with cleaner Tier 4 engines beginning in 2012 and 

conduct concurrent rebuilds of older engines to Tier 2.5 standards. This 

measure requires early introduction of U.S. EPA Tier 4 standards. 

Clean Up Existing Commercial Harbor Craft. Require owners of existing 

commercial harbor craft to replace old engines (both propulsion and auxiliary) 

with newer cleaner engines and/or add emission control technologies that clean 

up engine exhaust. ARB rulemaking for this proposed measure is underway. 

OFF-ROAD SOURCES 

Construction and Other Equipment

Cleaner In-Use Off-Road Equipment. Establish fleet average emission limits 

for off-road equipment (over 25 horsepower) that would require older, dirtier 

engines to be replaced with engines reflecting current technologies or retrofitted 

with emission control devices. ARB rulemaking for this proposed measure is in 

process. 

Agricultural Equipment

Agricultural Equipment Fleet Modernization. Accelerate the modernization of 

the fleet of agricultural equipment used in California, removing older, dirtier 

equipment from service to be replaced with engines reflecting cleaner 

technologies. 

Evaporative and Exhaust Strategies

New Emission Standards for Recreational Boats. Adopt catalyst-based 

standards (5 g/kW-hr) for new outboard and personal water craft (jet ski) engines 

and evaporative emission standards to address all sources of recreational boat 

evaporative emissions. 

Off-Road Recreational Vehicle Expanded Emission Standards. Adopt 

exhaust and evaporative emission standards to reduce the amount of ROG from 

off-highway motorcycles and all-terrain vehicles. 

Additional Evaporative Standards Portable Outboard Marine Tank 

Evaporative Standards. Set evaporative standards for removable fuel tanks used 

on outboard recreational boats. Refueling Gasoline Tank Evaporative 

Standards. Set evaporative standards for refueling gasoline tanks typically 

mounted on pickups and large recreational vehicles and used to refuel 

equipment and other smaller vehicles. Gas Station Refueling Hose Evaporative 

Standards. Set evaporative standards for gas station pump hoses. 
April 26, 2007 93 

Enhanced Vapor Recovery for Above Ground Storage Tanks. Implement an 

enhanced vapor recovery certification process and new performance standards 

and specifications for large fuel tanks used extensively in agricultural operations. 

AREAWIDE SOURCES 

Consumer Products

Tighten Standards. Tighten standards or require product reformulation for 

consumer products categories through several rulemakings through 2012. 

Pesticides

New Pesticide Strategies. The California Department of Pesticide Regulation 

will reduce emissions from commercial and agricultural pesticide use in California 

through reformulation, reduced usage, and innovative technologies and 

practices. 
April 26, 2007 94 

Improvements and Enhancements to California’s Smog Check Program 

California’s passenger vehicle emissions standards have been extremely 

effective -- a new 2005 car was 97 percent cleaner than a new 1980 car. In 

order to reduce the emissions necessary to reach air quality goals, however, the 

focus must shift to keeping vehicles clean over their lifetimes. The Smog Check 

program is the cornerstone of this effort, keeping over 400 tons of smog-forming 

emissions from entering the air each day. 

The State Strategy envisions an even stronger Smog Check program, adding 

tests that will reduce excess emissions and including vehicle types that are now 

exempt to better ensure that all passenger vehicles in California keep running 

clean. Staff has estimated that adding the following tests to Smog Check will 

reduce ROG and NOx emissions from passenger vehicles another 10 percent in 

2014. This equates to reducing about 11 tons per day of ROG and 12 tons per 

day of NOx in the South Coast in 2014. 

Low Pressure Evaporative Test 

Over half of smog-forming emissions from 1976 through 1995 cars comes from 

fuel evaporating from leaks in the fuel system. A functional check of the gas cap 

is currently included in Smog Check, but not a check of the vehicle’s fuel tank 

and vapor lines, which play an important part in controlling evaporative 

emissions. This measure would add a low pressure evaporative test to Smog 

Check to examine for leaks in the fuel tank and vapor lines. 

More Stringent Cutpoints 

One approach to getting more complete repairs and lower emissions is to 

increase the stringency of the inspection standards (cutpoints) used to determine 

if the vehicle initially passes or fails. This measure would set more stringent 

cutpoints, ensuring that more cars would have more complete and durable 

repairs. 

Annual Inspections for Older Vehicles 

Vehicles 15 years or older have a failure rate more than twice the average. This 

measure would require older vehicles to be tested annually, shortening the time 

they are emitting excess emissions prior to being repaired. 

Annual Inspections for High Annual Mileage Vehicles 

About 3 percent of cars are driven over 25,000 miles per year. These vehicles 

fail Smog Check at about twice the average rate. This measure would require 

high-mileage vehicles to be tested annually which would shorten the time they 

are emitting excess emissions prior to being repaired. 
April 26, 2007 95 

Add Visible Smoke Test. 

Excess soot from smoking passenger vehicles is estimated at about one and a 

half tons per day statewide and is a public health concern. An inspection for 

excessive smoke is currently not part of the Smog Check program, but soon will 

be due to newly enacted legislation (AB 1870, Lieber, Chapter 761 of 2006) that 

establishes visible smoke as a cause for Smog Check failure. 

Inspection of Light- and Medium-Duty Diesels. 

There are over 200,000 diesel passenger cars and trucks operating in California. 

While diesel vehicles have low ROG emissions, older diesels tend to emit higher 

levels of NOx and particulate matter than gasoline vehicles. Diesel vehicles, 

however, are not currently required to take part in the Smog Check program. 

This measure would develop a Smog Check inspection program for diesel 

passenger cars and trucks that would allow identification and repair of highemitting diesel vehicles. 

Inspection of Motorcycles. 

There are about 400,000 motorcycles registered in California. They are currently 

exempt from Smog Check. While motorcycles do not have a high rate of 

emission control deterioration, surveys indicate a high level of exhaust system 

tampering. This measure would require some form of motorcycle Smog Check 

inspections to help reduce excess motorcycle emissions. 
April 26, 2007 96 

Estimated Emission Reductions 

South Coast 

(tons per day) 2006 2014 2020 2023 

Baseline emissions 245 138 109 98 

Emission reductions: 

Low Pressure 

Evaporative Test 

 4.1 3.2 2.2 

More Stringent 

Cutpoints 

 0.8 0.6 0.6 

Annual Inspect Older 

Vehicles 

 3.1 2.5 2.3 

Annual Inspection for 

High Annual Mileage 

Vehicles 

 0.5 0.4 0.4 

Inspection of 

Motorcycles 

 2.0 2.0 2.0 

ROG 

Total potential 

reductions 10.5 8.7 7.5 

Baseline emissions 243 128 88 74 

More Stringent 

Cutpoints 

 2.0 1.4 1.1 

Annual Inspect Older 

Vehicles 

 7.2 4.9 4.2 

Annual Inspection for 

High Annual Mileage 

Vehicles 

 1.6 1.1 0.9 

Inspection of Lightand Medium-Duty 

Diesels 

 0.6 0.3 0.1 

Inspection of 

Motorcycles 

 0.6 0.6 0.6 

NOx 

Total potential 

reductions 12.0 8.3 6.9 

Baseline emissions 6.2 7.8 9.0 9.4 

Add Visible Smoke 

Test 

 0.2 0.2 0.2 

Inspection of Lightand Medium-Duty 

Diesels 

PM2.5 0.02 0.01 < 0.01 

Total potential 

reductions 0.2 0.2 0.2 

San Joaquin Valley 
April 26, 2007 97 

(tons per day) 2006 2014 2020 2023 

Baseline emissions 77 48 36 34 

Low Pressure 

Evaporative Test 

 0.8 0.6 0.4 

More Stringent 

Cutpoints 

 0.2 0.2 0.2 

Annual Inspect Older 

Vehicles 

 0.7 0.5 0.5 

Annual Inspection for 

High Annual Mileage 

Vehicles 

 0.2 0.1 0.1 

Inspection of 

Motorcycles 

 1.0 1.0 1.0 

ROG 

Total potential 

reductions 2.9 2.2 1.9 

Baseline emissions 68 40 28 24 

More Stringent 

Cutpoints 

 0.4 0.3 0.2 

Annual Inspect Older 

Vehicles 

 1.5 1.1 0.9 

Annual Inspection for 

High Annual Mileage 

Vehicles 

 0.8 0.5 0.5 

Inspection of Lightand Medium-Duty 

Diesels 

 0.3 0.2 0.2 

Inspection of 

Motorcycles 

 0.3 0.3 0.3 

NOx 

Total potential 

reductions 3.3 2.4 2.1 

Baseline emissions 1.4 1.8 2.1 2.4 

Add Visible Smoke 

Test 

 0.05 0.05 0.05 

Inspection of Lightand Medium-Duty 

Diesels 

PM2.5 < 0.01 < 0.01 < 0.01 

Total potential 

reductions 0.05 0.05 0.05 

Baseline emissions reflect adjustments not included in the SIP Emission 

Inventory Projections on ARB’s website. The adjustments include criteria 

pollutant benefits from the greenhouse gas limits for motor vehicles adopted in 

2004 and emission reductions from the Carl Moyer Program. 

Baseline emissions are for all light- and medium-duty passenger cars, SUVs and 

trucks, and all gasoline heavy-duty trucks. Reductions have been estimated in 

the following manner: 
April 26, 2007 98 

Low Pressure Evaporative Test—ARB staff has estimated the percent reduction 

in emissions from the low pressure test using before and after repair data 

collected in two studies done by ARB and one U.S. EPA study. The percent 

reduction was estimated separately for hot soak, diurnal, and running loss 

evaporative emissions. The percent reductions were then applied to EMFAC 

baseline evaporative emissions for the light duty fleet in order to calculate 

evaporative emissions benefits in tons per day. 

More Stringent Cutpoints—The reductions are based on more stringent initial 

inspection standards (cutpoints) taken from a study by Sierra Research using 

failure rate data collected from the California, Arizona, and Wisconsin inspection 

programs. Sierra Research identified model year groups of vehicles for which 

cutpoints could be lowered and estimated the impact on emission rates for each 

group. The fractional changes in emission rates were then applied to EMFAC 

baseline emissions to calculate emissions benefits in tons per day. 

Annual Inspections for Older Vehicles—Staff used the EMFAC emissions model 

to estimate the emissions reductions of an annual inspection compared to 

biennial inspection. EMFAC allows the user to choose either an annual or 

biennial program. Emission reductions were estimated by comparing the 

emissions with an annual program to those with a biennial program for vehicles 

over 15 years old. 15 years of age was selected because this is the point at 

which vehicles start failing at twice the fleet average yet account for less than 25 

percent of Smog Check tests. 

Annual Inspections for High Annual Mileage Vehicles—ARB conducted a 

voluntary inspection program on high mileage taxi cab fleets in the San Francisco 

and Los Angeles areas. Smog Check data suggest that up to 3 percent of the 

fleet accumulates high annual mileage. The estimated reductions from 20,000 

taxicabs were ratioed to the assumed 3 percent of the enhanced program area 

fleet driven high mileage. We assumed that one-half of the 3 percent of the fleet 

that are high annual mileage vehicles would be identified as accruing high annual 

mileage, tested annually, and repaired, resulting in emission reductions. 

Visible Smoke Test—Based on data from a survey done for South Coast AQMD, 

Sierra Research has estimated that approximately 200,000 smoking gasoline 

vehicles are driven daily statewide. Based on data from the South Coast survey 

and data from Southwest Research Institute testing, the benefits of repairing a 

smoking vehicle average 0.25 gram/mile. We are assuming that half of the 

200,000 smoking vehicles would fail the current tailpipe test in Smog Check. We 

have estimated benefits for the visible smoke test by assuming it would fail the 

other half (100,000) of the smoking vehicles per biennial cycle, which equals 

50,000 failures per year. Reductions statewide are based on repairing 50,000 

vehicles driving 30 miles per day with a 0.25 gram/mile total PM reduction. 

Inspection of Light and Medium Duty Diesels- Benefits are based on an 

inspection program as stringent as the current program for gasoline cars and 

trucks. We are assuming a diesel inspection program would get the same 
April 26, 2007 99 

percent reduction in emissions that the current enhanced Smog Check program 

is achieving. 

Inspection of Motorcycles—Benefits are based on assuming a motorcycle 

inspection program would get half of the percent reduction in emissions that the 

current enhanced Smog Check program is achieving. 

Timing 

Action: 2007-2008 

Expected Implementation: By 2010 

Staff Proposed SIP Commitment 

ARB staff proposes to work with BAR to begin to implement the measure in 

2010. ARB and BAR staff will initiate an effort to develop program improvements 

to achieve the reductions shown for the South Coast and San Joaquin Valley 

nonattainment areas in 2014, 2020, and 2023. The measure as implemented 

may provide more or less than the amount shown. 
April 26, 2007 100 

Expanded Passenger Vehicle Retirement 

The bulk of emissions from passenger vehicles comes from older vehicles. The 

Smog Check program helps older California cars run cleaner. To meet clean air 

goals, however, we need to reduce emissions from these older vehicles even 

more. Owners of vehicles that fail Smog Check inspections are currently given 

the option of fixing their vehicles or receiving a monetary incentive for voluntarily 

retiring them. This measure would expand the Smog Check vehicle retirement 

program to vehicles that are off-cycle from their Smog Check inspections. 

It is estimated that the vehicle retirement program could increase its scope from 

the current 18,000 vehicles per year statewide to approximately 50,000 per year 

in the South Coast and 10,000 per year in the San Joaquin Valley, which reflects 

retiring about half of one percent of vehicles subject to Smog Check in each 

region. The annual retirement of these vehicles in the South Coast and 

San Joaquin Valley would result in combined ROG and NOx emissions benefits 

of 2 percent of passenger vehicle emissions in 2014. 

Funding for vehicle retirement at both State and local program levels comes from 

fees on newer cars exempt from Smog Check. Increasing the scope of the 

program post 2010 would require additional State or local funding. 

Estimated Emission Reductions 

South Coast 

(tons per day) 2006 2014 2020 2023 

Baseline emissions 206 112 86 76 ROG 

Potential reductions 2.8 1.2 0.5 

Baseline emissions 204 101 65 53 NOx 

Potential reductions 2.4 1.3 0.2 

Baseline emissions 9.4 7.7 8.6 9.0 PM2.5 

Potential reductions 0.05 0.06 0.06 

San Joaquin Valley 

(tons per day) 2006 2014 2020 2023 

Baseline emissions 62 37 27 24 ROG 

Potential reductions 0.7 0.3 0.1 

Baseline emissions 58 31 19 16 NOx 

Potential reductions 0.5 0.3 0.04 

Baseline emissions 2.1 1.8 2.0 2.2 PM2.5 

Potential reductions 0.01 0.01 0.01 

Baseline emissions include emissions from light- and medium-duty passenger 

cars, trucks and sport utility vehicles. Baseline emissions reflect adjustments not 

included in the SIP Emission Inventory Projections on ARB’s website. The 

adjustments include emission reductions from the Carl Moyer Program and 
April 26, 2007 101 

criteria pollutant benefits from the greenhouse gas limits for motor vehicles 

adopted in 2004. 

Emission reductions were estimated assuming a 3-year credit life and that, on 

average, 16-year-old vehicles will be replaced with 8-year-old vehicles. These 

assumptions are based on data collected in ARB’s Voluntary Accelerated LightDuty Vehicle Retirement Program. 

Timing 

Action: 2008 - 2014 

Expected Implementation: 2008 - 2014 

Staff Proposed SIP Commitment 

ARB staff proposes to work with BAR to begin implementing the measure by 

2008. ARB and BAR staff will initiate an effort to expand the existing program to 

achieve the reductions shown for the South Coast and San Joaquin Valley 

nonattainment areas in 2014, 2020, and 2023. The measure as implemented 

may provide more or less than the amount shown. 
April 26, 2007 102 

Modifications to Reformulated Gasoline Program 

Gasoline fuel combustion is the major source of energy for passenger 

transportation. Since 1992, ARB has worked to ensure the use of cleaner 

burning gasoline to improve air quality throughout the state. One of the many 

components of the most recent gasoline reformulation program, CaRFG3, was 

the removal of the oxygenate MTBE due to concerns with groundwater 

contamination. However, the substitute oxygenate, ethanol, has resulted in 

greatly increased evaporative emissions due to fuel system permeation. 

This proposed measure would make modifications to the CaRFG3 program to 

eliminate or offset all ethanol permeation effects. The effects on ROG emissions 

from all gasoline-fueled on-road vehicles have been estimated to be a 3 percent 

increase in the South Coast and a 6 percent increase in the San Joaquin Valley. 

The effects are greater in the San Joaquin Valley due to much higher overall 

temperatures that affect permeation. 

ARB is scheduled to consider modifications to the CaRFG3 program in 2007. 

Estimated Emission Reductions 

South Coast

(tons per day) 2006 2014 2020 2023 

Baseline emissions 245 138 109 97 ROG 

Potential reductions 4.4 3.0 2.5 

San Joaquin Valley

(tons per day) 2006 2014 2020 2023 

Baseline emissions 77 48 36 34 ROG 

Potential reductions 2.9 1.6 1.3 

Baseline emissions are the emissions from all gasoline-fueled on-road vehicles. 

The estimated reductions are equal to the incremental ROG emissions resulting 

from ethanol permeation which will be offset by this measure. 

Timing 

Action: 2007 

Expected Implementation: Phase in starting 2010 

Staff Proposed SIP Commitment 

ARB staff proposes to commit to bring this measure to the Board by 2007. ARB 

staff will initiate a rule development process designed to achieve the reductions 

shown for the South Coast and San Joaquin Valley nonattainment areas in 2014, 
April 26, 2007 103 

2020, and 2023. The measure as proposed by staff to the Board or adopted by 

the Board may provide more or less than the amount shown. 
April 26, 2007 104 

Cleaner In-Use Heavy-Duty Trucks 

Federal and State engine standards will ensure that by 2010 all new diesel 

heavy-duty trucks are 90 percent cleaner than new 2006 trucks. This 

tremendous progress is on top of a 65 percent reduction in NOx and an 

85 percent reduction in particulate matter since 1990. Since trucks last a long 

time, we must bring newer trucks into the fleet at a faster pace, clean up older 

dirtier trucks, and keep the clean trucks clean longer to help meet air quality 

goals. 

Between now and 2014 existing programs reduce heavy duty truck emissions by 

50 percent. This proposed measure would reduce 2014 emissions another 

30 percent. The measure would accomplish these new reductions through a 

program to reduce emissions from the legacy fleet involving accelerating the 

turnover to new truck engines and retrofitting the remaining trucks with emission 

reduction devices, and through an excess emissions program. 

Legacy Fleet Emission Reduction Program

Newer heavy-duty trucks are typically used in long-haul service. After seven or 

eight years, they are often sold and their service is typically shifted to shorterhaul work. These trucks may remain in service within a given region for another 

twenty years or more. 

An in-use truck program would focus on overcoming the slower rate of heavyduty truck turnover to cleaner engines and retrofitting the remaining trucks with 

emission control devices such as particulate matter filters. The most 

comprehensive way to accomplish this would be through an “in-use” fleet rule 

that would require truck owners to meet specified emission levels. The proposed 

measure would address fleets operating in California regardless whether they are 

registered out of state. The emission reduction impact of the proposed in-use 

fleet program would be equivalent to replacing by 2014 approximately 30 percent 

of the oldest trucks with 2010 models year or newer trucks. The proposed 

measure would generate additional emission reductions beyond 2014, achieving 

reductions needed to meet the ozone air quality standard. 

ARB staff has recently begun informational workshops on a heavy-duty truck inuse fleet rule, and has started to identify and explore the many emissions 

inventory, technology, financial, and logistical issues involved in crafting the most 

effective rule possible. ARB staff will be studying and requesting feedback from 

stakeholders on many issues, including: the characteristics of trucks registered 

outside of California; cost implications, especially to truck owner-operators, and 

ways to avoid any competitive disadvantage for various categories of truck 

owners; and the most efficient use of limited public incentive funds to achieve 

maximum emission benefits and lessen financial burden on truck owners. 
April 26, 2007 105 

Excess Emissions Program

An estimate of deterioration of emission controls has historically been built into 

ARB’s projections of future emissions. As new engine technologies are 

introduced over the next few years, we need to ensure that the complex engine 

electronics and control devices used to make trucks so much cleaner are not 

more prone to failure, tampering or malmaintenance, and that deterioration does 

not reduce the benefits of the new standards. As the 2010 new engine standards 

are implemented, we will evaluate the in-use emissions and develop approaches 

to reduce excess emissions from trucks. 

Under an existing program, heavy-duty trucks are inspected at random roadside 

locations for excessive smoke, and are inspected for tampered emission control 

systems. Owners of vehicles that do not pass these inspections are issued 

citations that require prompt repairs and carry civil penalties. This measure could 

include an expansion of this program. 

While the design and evaluation of the specific program features has yet to be 

determined, ARB staff estimates that this concept has the potential to reduce 

NOx deterioration emissions by approximately 50 percent. 

Estimated Emission Reductions 

South Coast 

(tons per day) 2006 2014 2020 2023 

Baseline emissions 16 10 7 6 ROG 

Potential reductions 5.1 2.6 1.7 

Baseline emissions 238 131 79 65 NOx 

Potential reductions 47.3 26.9 18.3 

Baseline emissions 10.2 5.3 3.3 2.8 PM2.5 

Potential reductions 3.0 1.5 1.0 

San Joaquin Valley 

(tons per day) 2006 2014 2020 2023 

Baseline emissions 20 13 9 8 ROG 

Potential reductions 6.4 3.3 2.3 

Baseline emissions 277 150 88 72 NOx 

Potential reductions 61.4 30.2 21.2 

Baseline emissions 11.4 5.5 3.2 2.6 PM2.5 

Potential reductions 3.6 1.6 1.2 

Baseline emissions represent emissions from diesel-fueled medium- and heavy 

heavy-duty trucks. (Note: Baseline emissions reflect adjustments not included in 

the SIP Emission Inventory Projections on ARB’s website. The adjustments 
April 26, 2007 106 

include sleeper truck idling restrictions, diesel engine software upgrade, and 

emission reductions from the Carl Moyer Program.) 

Timing 

Action: 2008 

Expected Implementation: 2010-2015 

Staff Proposed SIP Commitment 

ARB staff proposes to commit to bring this measure to the Board by 2008. ARB 

staff will initiate a rule development process designed to achieve the reductions 

shown for the South Coast and San Joaquin Valley nonattainment areas in 2014, 

2020, and 2023. The measure as proposed by staff to the Board or adopted by 

the Board may provide more or less than the amount shown. 
April 26, 2007 107 

Ships 

Auxiliary Engine Cold Ironing and Other Clean Technology 

Cleaner Main Engines and Fuel 

Ships bring the majority of internationally traded goods to California. Due to the 

international nature of goods movement, marine vessels are subject to 

international and national standards set by the International Maritime 

Organization and U.S. EPA. However, ships are historically a largely 

unregulated sector. In 2006, ship emissions ranked as the largest contributor to 

SOx emissions, fifth largest contributor to NOx emissions, and seventh largest 

contributor to directly emitted PM2.5 in the South Coast. With the predicted 

growth in goods movement through California by 2020 (especially through the 

Ports of Los Angeles and Long Beach), emissions from ships are expected to 

increase significantly. 

In April 2006, ARB adopted the Emission Reduction Plan for Ports and Goods 

Movement in California, which calls for aggressive measures for ships and other 

port-related sources. The proposed emission reduction targets in these 

measures are the same goals set in that plan. Even before the adoption of the 

plan, work had begun to help meet its goals. In December 2005, ARB approved 

an Auxiliary Engine Fuel Rule that will phase in cleaner low-sulfur fuel from 2007 

to 2010. This rule will reduce SOx emissions from auxiliary engines by 96 

percent, PM emissions by 83 percent, and NOx emissions by 6 percent 

beginning in 2010. 

The proposed measures outlined below will continue to work toward the goals 

outlined in the goods movement plan to considerably reduce ship emissions. 

Marine fuel standards, cold ironing (port electrification), vessel speed reduction, 

and retrofitted diesel engines will ensure cleaner air around ports and reduced 

regional emissions. These measures are split by the type of engine used on a 

ship. Typically, ships use auxiliary engines while they are docked at the port or 

to run lights and other amenities while they are transiting. Main engines and 

boilers are used when ships are maneuvering within port waters or transiting 

throughout open waters. 

Auxiliary Engine Measures 

In addition to the Auxiliary Engine Fuel Rule, a new proposed measure for 

reducing auxiliary engine emissions is at-dock modifications including cold 

ironing and other advanced pollution reduction systems such as the “hood”. Cold 

ironing allows ships to turn off their auxiliary engines and instead plug into an 

electrical system for power when they are docked at the port. This is extremely 

beneficial to surrounding communities as it reduces exposure to multiple 

pollutants. The “hood” is a device that fits onto a ship’s exhaust stack and cleans 

the emissions. This measure would phase in the number of ships that will be 

capable of using cold ironing and technologies such as the “hood”. A 

combination of cold ironing and other at-dock technologies would reduce SOx 
April 26, 2007 108 

emissions by 54 percent in 2014 and 72 percent in 2023 and both NOx and PM 

emissions by 65 percent in 2014 and 82 percent in 2023. 

Main Engine and Boilers 

A Main Engine Fuel Rule, patterned after the Auxiliary Engine Fuel Rule, would 

help reduce emissions by introducing a cleaner, low-sulfur fuel beginning no later 

than 2010. This proposed rule would apply to ships using their main engine 

while maneuvering and transiting near the California coast and would reduce 

SOx emissions by 96 percent, PM emissions by 83 percent, and NOx emissions 

by 6 percent no later than 2010. 

A highly effective measure to reduce main engine emissions would be to 

increase the use of cleaner new engines or retrofitted engines. The measure 

could be implemented via regulation, incentives, voluntary agreements, or a 

combination of these approaches. By 2014, ships visiting California ports would 

have either new engines or a mix of retrofit technology (e.g., technology similar to 

a catalytic converter on a passenger car) that would achieve an overall reduction 

of NOx and PM of 30 percent. In 2023, ships visiting California would be 

equipped with an even cleaner technology mix, resulting in a 70 percent 

reduction of NOx, 50 percent reduction of PM, and 40 percent reduction of SOx. 

Vessel Speed Reduction (VSR) is an additional measure that would reduce main 

engine ship emissions. Presently, ships entering the Ports of Los Angeles and 

Long Beach have voluntarily agreed to reduce their speed to 12 knots within 

24 nautical miles of the ports. It is estimated that there is a 48 percent 

compliance rate associated with this voluntary measure. In order to further 

reduce main engine emissions, ARB would require ships to reduce their speeds 

to 12 knots within 40 nautical miles of the Ports of Los Angeles and Long Beach. 

The efficacy of the VSR program in reducing emissions changes over time as the 

vessel speeds are a function of the vessel type. It is estimated that ships will get 

larger and, therefore, their speeds will change. VSR is 30-35 percent effective in 

reducing SOx emissions, 40-50 percent effective in reducing PM2.5 emissions, 

and 35-50 percent effective in reducing NOx emissions over time. 

Estimated Emission Reductions 

(tons per day ship emissions 0-100 nautical miles from the California coast)
April 26, 2007 109 

South Coast (Auxiliary Engines)* 

(tons per day) 2006 2014 2020 2023 

Baseline emissions 17.2 1.1 1.5 1.8 SOx 

Potential reductions 0.0 0.4 0.7 0.7 

Baseline emissions 26.6 37.2 48.7 56.3 NOx 

Potential reductions 0.0 18.5 28.3 30.8 

Baseline emissions 2.2 0.6 0.8 0.9 PM2.5 

Potential reductions 0.0 0.3 0.4 0.5 

* ARB 2005 Auxiliary Engine Fuel Rule emission reductions are accounted for in the baseline. 

South Coast (Main Engines and Boilers) 

(tons per day) 2006 2014 2020 2023 

Baseline emissions 14.7 20.7 26.3 29.7 SOx 

Potential reductions 0.0 19.7 25.4 28.8 

Baseline emissions 24.4 33.4 41.4 46.3 NOx 

Potential reductions 0.0 20.0 32.3 39.9 

Baseline emissions 1.8 2.6 3.3 3.7 PM2.5 

Potential reductions 0.0 2.4 3.1 3.6 

Since the control measures apply to the same source, the control percentages 

were applied sequentially to calculate total reductions. 

Timing 

Main Engine Fuel ATCM 

Action: 2007 

Expected Implementation: 2007-2010. 

Cold Ironing 

Action: 2007-2008 

Expected Implementation: Starting in 2010 – 10 percent by 2010, 60 percent by 

2014, and 80 percent by 2020. 

Cleaner Engines (New and Retrofits) 

Action: 2009 

Expected Implementation: Phase-in starting in 2010. 

Vessel Speed Reduction 

Action: 2007 

Expected Implementation: 2008. 

Staff Proposed SIP Commitment 

ARB staff proposes to commit to bring this measure to the Board beginning 2007. 

ARB staff will initiate a rule development process designed to achieve the 
April 26, 2007 110 

reductions shown for the South Coast and San Joaquin Valley nonattainment 

areas in 2014, 2020, and 2023. The measure as proposed by staff to the Board 

or adopted by the Board may provide more or less than the amount shown. 
April 26, 2007 111 

Port Truck Modernization 

Trucks serving California ports are a vital part of the goods movement system. 

Trucks transfer incoming cargo containers from the ports to intermodal 

distribution centers for transport via long-haul rail or truck to their ultimate 

destination in California or throughout the U.S. Trucks also carry agricultural 

products from the Central Valley and other farming regions, and exports, to the 

ports for shipment overseas. Port-related truck activity is growing. The number 

of containers carried by truck to and from the Ports of Los Angeles and 

Long Beach, for example, is expected to grow by a factor of 2.5 within twenty 

years. Because trucks in port service tend to be older and dirtier than the truck 

fleet as a whole, it is important that the impact of these vehicles be mitigated 

more quickly to address community health issues and to meet air quality goals. 

This proposed measure would reduce NOx and diesel PM2.5 emissions from the 

existing port truck fleet, as well as additional trucks entering port service. The 

basis for this strategy closely follows the goals outlined in the Emission 

Reduction Plan for Ports and Goods Movement in California (April 2006). 

Rulemaking is currently in progress for the port truck modernization rule, which 

would take place in two phases. The Ports of Los Angeles and Long Beach are 

also developing approaches to reduce port truck emissions on a parallel track. A 

mix of regulatory and other actions may be used to achieve the emission 

reduction target. 

With the current ARB concept, trucks in regular port service that are model year 

1993 and older would be replaced with 1998 and newer trucks by 2011. In 

addition, all trucks in regular port service would be retrofitted with verified devices 

that reduce diesel PM by 85 percent or more. Retrofits that also provide NOx 

reductions would be used to the greatest extent feasible. The second phase 

would require pre-2003 trucks in regular port service to meet or exceed 2010 

federal engine standards by the end of 2017, and pre-2007 trucks in regular port 

service to meet or exceed 2010 federal engine standards by the end of 2019. 

Additionally, the proposal would require trucks entering port service for the first 

time between 2008 and 2011 to meet or exceed 2003 federal engine standards 

and be equipped with diesel particulate filters. Trucks entering port service 

between 2012 and 2014 would need to meet or exceed 2007 federal engine 

standards, and trucks entering port service in 2015 and later would need to meet 

or exceed 2010 federal engine standards. 

This proposed measure would reduce port truck NOx emissions in the 

South Coast Air Basin by about 10 percent in 2014 and 50 percent in 2023. 

Also, diesel PM emissions from port trucks in the South Coast Air Basin would be 

reduced by more than 50 percent in 2014. 

The reductions from this measure would complement the reductions achieved by 

the proposed cleaner in-use heavy-duty truck measure. The regulation currently 

being developed for port trucks would apply only to those heavy heavy-duty 

trucks in primary port service. The private fleet rule currently under development 
April 26, 2007 112 

would provide the reductions cited for the in-use heavy-duty truck measure by 

including trucks not in port service as well as trucks in the medium heavy-duty 

category. 

Estimated Emission Reductions 

South Coast 

(tons per day) 2006 2014 2020 2023 

Baseline emissions 22 18 15 15 NOx 

Potential reductions 2 8 7 

Baseline emissions 1.0 0.8 0.6 0.6 PM2.5 

Potential reductions 0.5 0.3 0.3 

Baseline emissions are for port trucks, based on inventories developed for the 

Emission Reduction Plan for Ports and Goods Movement. Emission reduction 

estimates are based on the assumption that port trucks are older, on average, 

than the fleet as a whole (age distribution was based on a 2002 study by 

Starcrest International). The number of trucks in regular port service is projected 

to grow from approximately 12,000 in 2005 to 15,000 in 2010, 18,000 in 2015 

and 21,000 in 2020. Staff assumed that port trucks make trips of lower average 

speed (35 mph), owing to short hauls to distribution centers and congested 

conditions near the ports. 

Port truck emissions are small for the San Joaquin Valley so reductions for this 

measure are not significant. Goods movement-related emissions from trucks in 

the San Joaquin Valley are generated primarily by line-haul trucks and not port 

trucks. Line-haul truck emissions are significantly reduced in the proposed 

cleaner in-use heavy-duty truck measure. 

Timing 

Action: 2007-2008 

Expected Implementation: 2008-2020 

Staff Proposed SIP Commitment 

ARB staff proposes to commit to bring this measure to the Board by 2008. ARB 

staff will initiate a rule development process designed to achieve the reductions 

shown for the South Coast nonattainment area in 2014, 2020, and 2023. The 

measure as proposed by staff to the Board or adopted by the Board may provide 

more or less than the amount shown. 
April 26, 2007 113 

Accelerated Introduction of Cleaner Line-Haul Locomotives 

Line-haul locomotives used to pull rail cars long distances account for about 

95 percent of total train emissions. U.S. EPA proposed new Tier 4 standards to 

reduce NOx and PM emissions by 90 percent. These emission standards would 

build on existing federal requirements for using low sulfur diesel fuel. They 

include new engine standards and rebuild standards, and require aftertreatment 

technology. Since the useful life of a locomotive can exceed 30 years, the 

accelerated use of Tier 4 or equivalent technology is necessary to provide diesel 

PM and NOx reductions needed to meet attainment deadlines. ARB is pushing 

U.S. EPA to accelerate introduction of Tier 4 standards on an earlier timeframe, 

beginning in 2012. 

The proposed measure calls for replacing existing locomotive engines with Tier 4 

engines beginning in 2012 and conducting concurrent rebuilds of older engines 

to Tier 2.5 standards. This can only occur once U.S. EPA accelerates 

implementation of the Tier 4 engine standards for locomotives. It is estimated 

that by 2023, this measure would reduce NOx by 70 percent and direct PM2.5 by 

about 75 percent. 

Estimated Emission Reductions 

South Coast 

(tons per day) 2006 2014 2020 2023 

Baseline emissions 2.3 2.3 2.4 2.5 ROG 

Potential reductions 0.7 1.8 1.9 

Baseline emissions 26.7 18.3 21.0 22.6 NOx 

Potential reductions 4.3 13.4 15.6 

Baseline emissions 0.78 0.71 0.75 0.77 PM 

Potential reductions 0.20 0.56 0.59 

San Joaquin Valley 

(tons per day) 2006 2014 2020 2023 

Baseline emissions 1.6 1.5 1.6 1.6 ROG 

Potential reductions 0.5 1.2 1.3 

Baseline emissions 21.5 19.9 20.6 21.1 NOx 

Potential reductions 7.2 15.6 16.4 

Baseline emissions 0.58 0.53 0.53 0.54 PM 

Potential reductions 0.18 0.42 0.46 

Baseline emissions represent line-haul and switcher locomotives. 

Emission reduction estimates are based on, beginning in 2012, 10 percent of the 

existing engines being replaced by Tier 4 engines and 5 percent upgraded to Tier 

2.5 standards until 100 percent of the statewide fleet has been upgraded. 
April 26, 2007 114 

Timing 

Action: U.S. EPA adopts Tier 4 standards in 2007. Voluntary agreement to 

accelerate implementation – 2008. 

Expected Implementation: Introduction of 10 percent Tier 4 and upgrades to 

Tier 2.5 at 5 percent are expected to begin 2012. 

Staff Proposed SIP Commitment 

ARB staff will continue to encourage U.S. EPA to accelerate implementation of 

the Tier 4 engine standards. Once the new standards are in place, ARB staff 

commits to work with the railroads to bring the cleanest locomotives in to 

California service. 
April 26, 2007 115 

Clean Up Existing Commercial Harbor Craft 

Commercial harbor craft are marine vessels that operate primarily along 

California’s coastline and inland waterways. They include tugboats, work boats, 

crew/supply boats, ferries, excursion boats, commercial and sport fishing boats, 

and other harbor vessels. The diesel propulsion and auxiliary engines used on 

these vessels were built for long life and have essentially uncontrolled emissions. 

U.S. EPA adopted harbor craft engine standards that apply to new engines 

beginning in 2004. The engines meeting the new U.S. EPA standards have 

roughly 50 percent less NOx than uncontrolled engines. Since the useful life of 

harbor craft vessels is so long, the benefits of new engine standards accrue 

slowly over time. However, to accelerate emission reductions, many of these 

vessels can be repowered with newer, cleaner engines. 

There are also emission control technologies, called “add-on” controls or retrofits, 

that can reduce both NOx and diesel particulate matter. Retrofit control 

technologies have been shown to dramatically reduce emissions when used with 

heavy-duty diesel engines in land-based operations and can be adapted to 

marine applications. 

ARB is in the process of developing a regulation that would require owners of 

existing commercial harbor craft to replace old engines with newer cleaner 

engines and/or to add retrofit emission control technologies. It would address 

both propulsion and auxiliary engines. The regulation would take into account 

the fact that harbor craft vessel types are diverse and may require various 

combinations of emission reducing strategies and that some vessel 

configurations may not accommodate retrofits. Fishing boats in particular will be 

difficult to retrofit and may face difficult unique economic constraints. 

The proposed regulation is one of the measures in ARB’s Goods Movement Plan 

and is scheduled for adoption in 2007. ARB staff estimates that the harborcraft 

regulations will reduce NOx and PM emissions 30 percent by 2014, and 40 

percent by 2020,based on the capabilities of existing control technologies. 
April 26, 2007 116 

Estimated Emission Reductions 

South Coast 

(tons per day) 2006 2014 2020 2023 

Baseline emissions 23.1 15.7 12.7 12.7 NOx 

Potential reductions 4.6 5.1 5.9 

Baseline emissions 1.1 0.7 0.6 0.6 

PM2.5 Potential reductions 0.2 0.2 0.3 

The baseline harbor craft inventory is taken from the Emission Reduction Plan for 

Ports and Goods Movement, April 2006. Direct PM2.5 numbers reflect diesel 

PM. Emission reduction estimates assume the regulation will reduce emissions 

30 percent by 2014, and 40 percent by 2020. (Emission reductions were 

estimated for the San Joaquin Valley but found to be insignificant.) 

Timing 

Action: 2007 

Expected Implementation: 2009-2018 

Staff Proposed SIP Commitment 

ARB staff proposes to commit to bring this measure to the Board by 2007. ARB 

staff will initiate a rule development process designed to achieve the reductions 

shown for the South Coast nonattainment area in 2014, 2020, and 2023. The 

measure as proposed by staff to the Board or adopted by the Board may provide 

more or less than the amount shown. 
April 26, 2007 117 

Cleaner In-Use Off-Road Equipment 

Adopted emission standards for new off-road diesel engines are becoming 

increasingly more stringent, ensuring that new construction, mining, industrial, oil 

drilling and airport ground support equipment become progressively cleaner. 

The cleanest standards for NOx emissions in these categories will phase in from 

2013-2015. However, large diesel off-road equipment with more than 25 

horsepower remain in use for long periods of time, often 25 years or more. This 

long life means that new, lower emitting engines are introduced into fleets 

relatively slowly with the result that the emission reductions and associated 

health benefits from these cleaner engines will also be slow to materialize. 

Accelerating the introduction of cleaner engines and emissions control 

technologies into the statewide fleet is necessary to meet air quality standards. 

This proposed measure would require owners of equipment larger than 

25 horsepower to meet a stringent average emissions level across all of their 

equipment. The fleet average approach provides equipment owners flexibility in 

how they will comply, including: swapping older, dirtier engines with newer, 

cleaner engines; purchasing newer equipment (with cleaner engines); and, 

adding emission control devices to older engines. It also allows fleet owners to 

maintain a fleet with some engines which are cleaner than the fleet average and 

others which are dirtier, so that, on average, the fleet meets the target. ARB staff 

is also proposing idling limits similar to those the Board has adopted for heavy 

duty trucks. 

ARB staff has proposed a statewide in-use off-road diesel equipment regulation 

which could require initial NOx and PM emissions averages to be met, with 

increasingly lower emissions averages over time. Staff began work on the rule 

in 2004 as part of the Diesel Risk Reduction Program. During early SIP 

development work in 2006, staff identified the necessity for large NOx emission 

reductions from off-road equipment and other diesel sources to meet the healthbased federal air quality standards. Consequently, staff revised the control 

concept extensively to meet California’s clean air needs relative to diesel 

particulates, ozone, and PM2.5. 

This measure would reduce NOx emissions from large diesel off-road equipment 

in the South Coast Air Basin by approximately 10 percent in 2014 and by about 

30 percent in 2023. 
April 26, 2007 118 

Estimated Emission Reductions

South Coast 

(tons per day) 2006 2014 2020 2023 

Baseline Emissions 20.2 13.3 9.3 8.1 ROG 

Potential Reductions 2.7 2.9 1.9 

Baseline Emissions 143.2 96.1 59.0 46.5 NOx 

Potential Reductions 10.5 18.7 13.9 

Baseline Emissions 8.1 4.9 2.6 1.8 PM2.5

Potential Reductions 2.6 1.8 1.3 

San Joaquin Valley 

(tons per day) 2006 2014 2020 2023 

Baseline Emissions 6.1 4.2 3.1 2.7 ROG 

Potential Reductions 0.9 1.0 0.6 

Baseline Emissions 47.6 32.8 21.6 17.7 NOx 

Potential Reductions 3.7 7.0 5.4 

Baseline Emissions 2.3 1.5 0.8 0.6 PM2.5

Potential Reductions 0.8 0.6 0.4 

Baseline emissions are from the OffRoad2007 model. 

Emission reduction estimates are based on expected emission reductions from 

ARB’s proposed In-Use Off-Road Diesel Vehicle rule currently under 

development. Because the proposed rule is under development, the estimated 

reductions are subject to change. 

The rule proposal applies declining fleet averages for large fleets beginning in 

2010. For NOx, the fleet averages for 2014 for most engine sizes are more 

stringent than Tier 1 emission levels. The corresponding PM fleet averages for 

2014 are cleaner than Tier 2 emission levels. In 2020, fleet averages for NOx 

and PM are more stringent than Tier 3 emission levels. The means to reach 

these fleet averages are left to the equipment owners to decide. However, if a 

fleet cannot meet the NOx averages, it must turnover 8 percent of its total 

horsepower per year to cleaner engines (minimum Tier 2 engine) in the initial 

years and 10 percent per year in years after 2015. A fleet must retrofit 20 

percent of its total horsepower with diesel particulate filters if it cannot meet the 

PM average. The rule would also restrict unnecessary idling. 

Timing 

Action: 2007 

Expected Implementation: Phase-in starting 2008 
April 26, 2007 119 

Staff Proposed SIP Commitment 

ARB staff proposes to commit to bring this measure to the Board by 2007. ARB 

staff will initiate a rule development process designed to achieve the reductions 

shown for the South Coast and San Joaquin Valley nonattainment areas in 2014, 

2020, and 2023. The measure as proposed by staff to the Board or adopted by 

the Board may provide more or less than the amount shown. 
April 26, 2007 120 

Cleaner In-Use Agricultural Equipment 

New engines used in agricultural operations must meet the same standards as 

other off-road engines, ensuring that new equipment become progressively 

cleaner. Just as in other off-road applications, diesel agricultural equipment can 

remain in use for long periods of time. This long life means that new, lower 

emitting engines are introduced into fleets relatively slowly with a direct impact on 

the pace that emission reductions materialize. 

The cleanup of agricultural in-use equipment is primarily an issue in the 

San Joaquin Valley with its large agricultural economy. Natural turnover of the 

agricultural fleet will reduce emission significantly by the Valley’s expected 2024 

ozone attainment deadline. Modeling for the Valley’s PM2.5 SIP due in 2008 will 

show what accelerated fleet modernization may be needed. Once that 

information is available, ARB staff will quantify reductions from this measure. 

ARB staff is also supporting efforts to obtain additional incentive funding to 

accelerate progress. 

 San Joaquin Valley 

(tons per day) 2006 2014 2020 2023 

Baseline Emissions 13 7 4 3 ROG 

Potential Reductions NYQ NYQ NYQ 

Baseline Emissions 62 38 23 18 NOx 

Potential Reductions NYQ NYQ NYQ 

Baseline Emissions 3.5 2.0 1.1 0.7 PM2.5

Potential Reductions NYQ NYQ NYQ 

Timing 

Action: 2009-2010 

Expected Implementation: To Be Determined 

Staff Proposed SIP Commitment 

ARB staff proposes to commit to bring this measure to the Board by 2010. ARB 

staff will initiate a rule development process designed to achieve emission 

reductions for the San Joaquin Valley nonattainment area in 2014, 2020, and 

2023. The estimated emission reductions have yet to be quantified. 
April 26, 2007 121 

New Emission Standards for Recreational Boats 

Recreational boat engines are broadly divided into two categories: outboard 

boats/personal water craft (PWC) and inboard/sterndrive. Outboard and PWC 

motors until recently were predominantly 2-stroke engines. Inboard/sterndrive 

engines are typically automotive spark-ignition engines adapted for boats that 

must now comply with a 5.0 g/kW-hr exhaust standard by 2009, which can be 

achieved with three-way catalytic converters and oxygen sensor feedback 

controls. Although ARB previously adopted exhaust emission standards for 

outboard/PWC engines, lower exhaust standards to further reduce emissions are 

possible by adapting the emission control technology used for inboard/sterndrive 

engines. This measure calls for the implementation of a tighter, catalyst-based 

exhaust standard of 5.0 g/kW-hr for outboard/PWC engines to be phased-in by 

2013. Only 4-stroke engines are expected to be able to comply with this tighter 

standard. 

Evaporative emissions represent about one fourth of the total ROG emissions 

from recreational boat engines. There are no state or federal evaporative 

emission standards for any type of recreational boats. This measure calls for an 

evaporative emission standard that will address all sources of boat evaporative 

emissions (tank, carbon canisters, fuel lines, etc.). The technology needed to 

achieve evaporative standards for boats is readily adaptable from that used in 

automobiles and small off-road equipment. 

Estimated Emission Reductions 

South Coast 

(tons per day) 2006 2014 2020 2023 

Baseline Emissions 64.1 52.8 50.3 50.8 ROG 

Potential Reductions 0.0 4.2 12.8 17.6 

Baseline Emissions 16.1 17.1 18.0 18.3 NOx 

Potential Reductions 0.0 0.4 1.6 2.4 

San Joaquin Valley 

(tons per day) 2006 2014 2020 2023 

Baseline Emissions 20.1 17.1 16.6 16.8 ROG 

Potential Reductions 0.0 1.3 3.8 5.3 

Baseline Emissions 5.3 5.6 5.7 5.8 NOx 

Potential Reductions 0.0 0.1 0.4 0.6 

The baseline estimates are comprised of summer average exhaust and 

evaporative emissions for all types of recreational boats. 

Exhaust emission reduction estimates for outboard and PWC are based on the 

percent reduction estimates from ARB’s 2001 regulation for inboard/sterndrive 
April 26, 2007 122 

engines, which reduced the exhaust standards by the same increment (from 16 

to 5 g/kW-hr). 

Evaporative emission reductions are based on an estimated 70 percent control of 

evaporative emissions for all recreational boats of model year 2012 and newer. 

The 70 percent control is a composite that accounts for the cumulative reductions 

from all sources of boat evaporative emissions (tank, carbon canisters, fuel lines, 

etc.). 

Timing 

Action: Exhaust standard by 2010; evaporative standard by 2009. 

Expected Implementation: Exhaust standard by 2013; evaporative standard by 

2012. 

Staff Proposed SIP Commitment 

ARB staff proposes to commit to bring this measure to the Board by 2010. ARB 

staff will initiate a rule development process designed to achieve the reductions 

shown for the South Coast and San Joaquin Valley nonattainment areas in 2014, 

2020, and 2023. The measure as proposed by staff to the Board or adopted by 

the Board may provide more or less than the amount shown. 
April 26, 2007 123 

Off-Road Recreational Vehicle Expanded Emission Standards 

Exhaust Standards

Exhaust emissions from off-road recreational vehicles are controlled to a much 

lesser extent than on-road motorcycles or on-road cars and trucks with the result 

that this category of vehicles is showing an increase in emissions into the future. 

In 1994, ARB approved exhaust emission standards and test procedures for 

off-road recreational vehicles, including off-highway motorcycles and all terrain 

vehicles (ATVs). In 1998, ARB revised the rules to allow non-compliant vehicles 

to be sold and operated outside the summer season or in locations where ozone 

levels are lower. 

Off-road recreational vehicles lag in emission reductions for a number of reasons 

including technical limitations, cost, and tampering. Another concern is that the 

California market is not large enough for off-road recreational vehicle 

manufacturers to produce vehicles that would comply with more stringent 

California exhaust standards. This could lead to compliance problems if 

consumers either purchase off-road recreational vehicles out-of-state or falsely 

certify that the vehicles they purchase are intended for use in competition. The 

most effective strategy would be for U.S. EPA to establish tighter exhaust 

standards for all off-road recreational vehicles, thereby precluding the potential 

for California consumers to purchase and operate non-complying (and higher 

emitting) vehicles. 

This measure calls for reducing exhaust emissions by 50 percent from new offhighway motorcycles and ATVs beginning in 2012 using proven automotive and 

on-road motorcycle exhaust emission reduction technologies. Due to the high 

fleet turnover and overall growth of the fleet, ARB staff estimates that the 

measure would reduce ROG exhaust emissions from off-road recreational 

vehicles 25 percent by 2014 and 50 percent by 2023. 

Evaporative Standards

In 2002, U.S. EPA approved a rule that required all off-road recreational vehicles 

to comply with evaporative standards beginning with 2008 vehicles. However, 

the standards only control permeation from the fuel tank and hoses. In July 

2006, ARB approved evaporative emission standards that harmonized with 

existing U.S. EPA regulations. 

This measure would reduce ROG evaporative emissions by 50 percent from 

off-highway motorcycles and ATVs beginning in 2012 using proven automotive 

and on-road motorcycle evaporative emission reduction technologies. Due to the 

high fleet turnover and overall growth of the fleet, ARB staff estimates that the 

measure would reduce ROG evaporative emissions from off-road recreational 

vehicles 25 percent by 2014 and 50 percent by 2023. 
April 26, 2007 124 

Estimated Emission Reductions 

South Coast 

(tons per day) 2006 2014 2020 2023 

Baseline emissions 8 9 11 13 ROG 

Potential reductions 2.4 5.1 6.4 

San Joaquin Valley 

(tons per day) 2006 2014 2020 2023 

Baseline emissions 7 9 11 12 ROG 

Potential reductions 2.2 4.9 6.1 

Baseline ROG emissions (exhaust + evaporative) are for all off-road motorcycle 

and ATVs in each region. Emission reduction estimates are from ARB’s off-road 

motor vehicle emissions model programmed to calculate the potential impact of 

reducing new engine exhaust and evaporative emissions by 50 percent 

beginning in 2012. 

Timing 

Action: By 2010 

Expected Implementation: 2012-2015 

Staff Proposed SIP Commitment 

ARB staff proposes to commit to bring this measure to the Board by 2010. ARB 

staff will initiate a rule development process designed to achieve the reductions 

shown for the South Coast and San Joaquin Valley nonattainment areas in 2014, 

2020, and 2023. The measure as proposed by staff to the Board or adopted by 

the Board may provide more or less than the amount shown. 
April 26, 2007 125 

Additional Evaporative Emission Standards 

Portable Outboard Marine Tank Evaporative Standards

Portable outboard marine tanks (OMT) are small-capacity tanks (usually less 

than 12 gallons) that supply fuel to marine outboard engines. Unlike larger 

vessels with permanently mounted fuel tanks, many small and medium size 

outboard boats use removable tanks to allow both the engine and fuel tank to be 

removed for transport or storage. OMTs are not subject to any emission 

standards and as a result have relatively high evaporative emissions. DMV and 

other data indicate that there were approximately 200,000 registered outboard 

vessel owners in California in 2005. If we assume one tank per outboard, the 

statewide inventory would be 200,000 OMTs with statewide emissions of 

approximately six tons per day. Baseline emissions for future years and regions 

of the state were scaled from this estimate on the basis of emission inventories of 

evaporative emissions from outboard boat engines smaller than 15 horsepower. 

Diurnal and permeation standards for OMTs and associated equipment are 

expected to have the same emission reduction efficiencies as controls required 

by ARB’s 2005 regulation for portable fuel containers, and would reduce 

emissions by 50 percent in 2014 and 75 percent in 2023. This measure would 

be applied to new tanks, resulting in a phase-in over the useful lives of existing 

tanks.

Refueling Gasoline Tank Evaporative Standards

Refueling gasoline tanks (from 30 to 100 gallons) are usually mounted on a 

vehicle and used to refuel other motor vehicles. Some examples include tanks 

on recreational vehicles, like toy haulers, for fueling off-highway recreational 

vehicles or tanks on pickup trucks for fueling off-road or agricultural equipment. 

There are an estimated 150,000 refueling tanks in California 

ARB staff are currently conducting surveys to determine accurate populations as 

well as testing to calculate more accurate emissions. Rough preliminary 

statewide estimates of evaporative emissions from refueling gasoline tanks are 

approximately six tons per day. Future year and regional baseline estimates are 

scaled from this statewide estimate on the basis of recreational offroad vehicle 

evaporative emissions. 

Setting evaporative standards for refueling tanks would reduce ROG emissions 

by 60-70 percent, depending on which technology is utilized. Control 

technologies being considered include passive purge carbon canisters and 

insulation. These technologies would be applied to new tanks and would be 

phased-in over the useful lives of existing tanks. 
April 26, 2007 126 

Gas Station Refueling Hose Evaporative Standards

Gas station refueling hoses are co-axial hoses that transfer fuel from the filling 

station pump to a vehicle’s fuel tank and return displaced gasoline vapors from 

the vehicle fuel tank to the gasoline storage tank. Evaporative emissions occur 

through the hose material. There are an estimated 120,000 gas station refueling 

hoses statewide with estimated emissions of three tons per day. 

Setting evaporative standards for gas station refueling hoses would reduce ROG 

emissions by 70-98 percent, depending on which technology is utilized. These 

estimates are based on previous standards for low permeation vehicle fuel hose 

and initial ARB and industry testing results. 

Estimated Emission Reductions 

Emission inventories are being reassessed for these evaporative source 

categories. For SIP purposes, emission reductions are not quantified for these 

measures so no benefits are included in the proposed SIP. 

The measures are described here for informational purposes only. Reductions 

from these measures will be accounted for in future SIP updates. For information 

purposes only, reductions from the three measures combined are expected to be 

about 3 tons per day in the South Coast in 2020. 
April 26, 2007 127 

Enhanced Vapor Recovery for 

Above Ground Storage Tanks 

Above ground storage tanks are large gasoline storage tanks used extensively in 

agricultural operations. Typical tanks have capacities ranging from 250 to 

12,000 gallons. Above ground storage tanks are becoming increasingly popular 

due to their superior leak detection capabilities. Because these tanks are 

exposed to ambient air temperatures, emissions are greater than from 

underground tanks. Annual statewide ROG emissions from all tanks in 2004 

totaled 3.1 tons per day. Emission reductions are possible and feasible with an 

enhanced vapor recovery certification process and new performance standards 

and specifications. 

This proposed measure calls for reducing emissions by 90 percent from new 

above ground storage tanks, by 76 percent from retrofitting existing nonagricultural tanks, and by 60 percent from retrofitting existing agricultural tanks. 

This measure would be implemented beginning in 2007, and by 2011 would 

reduce statewide ROG emissions from tanks by two tons per day. The estimated 

control efficiencies are based on field testing of proposed controls. The 

retrofitting of existing tanks would be phased in between 2007 and 2011 with 

25 percent of tanks being converted each year. ARB staff is currently analyzing 

what the emission reductions would be for each region. 

Estimated Emission Reductions 

Statewide 

(tons per day) 2006 2014 2020 2023 

Baseline emissions 3.2 3.5 3.8 3.9 ROG 

Potential reductions -- 2.3 2.4 2.5 

The statewide emissions for above ground storage tanks have not been 

apportioned by region, and therefore are not included in the baseline inventory. 

Since the emissions are not in the inventory, the potential reductions listed here 

are not included as an emission reduction commitment in the proposed State 

Strategy. 

Timing 

Action: 2007 

Implementation: Phase-in starting 2008 

Staff Proposed SIP Commitment 

ARB staff proposes to commit to bring this measure to the Board by 2007. ARB 

staff will initiate a rule development process designed to achieve the reductions 

shown for the South Coast and San Joaquin Valley nonattainment areas in 2014, 
April 26, 2007 128 

2020, and 2023. The measure as proposed by staff to the Board or adopted by 

the Board may provide more or less than the amount shown. 
April 26, 2007 129 

Consumer Products Program 

Chemically formulated consumer products such as automotive care products, 

household care products, and personal care products have been regulated as a 

source of ROG emissions in five rulemakings since 1989. As a result of these 

measures, statewide emissions from consumer products in 2010 will be reduced 

40 percent from uncontrolled levels. Despite this progress, population growth in 

the years ahead is expected to reverse the downward trend of emissions from 

consumer products as early as 2008, after the latest standards become effective. 

The magnitude of emissions from this sector indicates that additional controls for 

this sector remain important, even though the average photochemical reactivity 

of the ROG emissions from the consumer product sector is approximately onethird that of motor vehicle exhaust. Consumer products are expected to become 

the largest source of ROG emissions in the South Coast Air Basin, and the third 

largest source in the San Joaquin Valley Air Basin by 2020. 

This proposed measure would continue ARB’s commitment to reduce ROG 

emissions from consumer products. The current program uses industry surveys 

to gather information about sales trends and product formulations. Staff uses 

survey data along with trade journals, patents, and other technical information to 

propose mass-based ROG limits. Staff will continue to investigate any and all 

opportunities for emission reductions from mass-based limits by taking 

advantage of emerging low-emitting technologies. However, the ability to 

achieve significant reduction from mass-based standards is waning, so staff will 

likely be shifting the focus to other potential emission reduction opportunities. 

One such measure would include investigating emission reduction opportunities 

through reactivity-based standards in most categories. A reactivity-based 

approach relies on the scientific principle that different chemical compounds form 

different amounts of ozone in the atmosphere, rather than the mass-based 

approach that reduces ozone formation by reducing all reactive organic gases. 

In the future, it is likely that further emission reductions from the consumer 

products source category will not be feasible using conventional approaches. 

Staff will work with stakeholders to explore alternative market-based mechanisms 

that would encourage the development, distribution, and purchase of cleaner, 

very low, or zero emitting products. Examples of mechanisms to explore are a 

multi-media labeling program, programs where companies set their own 

emissions reduction goals, and the use of the media for public education. If 

these mechanisms cannot produce meaningful emission reductions from the 

consumer products source category, then other approaches would be evaluated. 

Examples of alternative approaches are the purchase of ROG credits and the 

funding of special projects to reduce emissions or accelerate reductions from 

pollution sources outside of the consumer products industry. 

The above approaches could be implemented through several rulemakings and 

would achieve approximately 30-40 tons per day ROG reductions statewide, 

equivalent to 13-17 tons per day in the South Coast, in the 2008 to 2014 

timeframe. The 2006 measure was adopted by the ARB Board in 
April 26, 2007 130 

November 2006 with phase-in implementation from 2008 to 2010. 

Estimated Emission Reductions 

South Coast 

(tons per day) 2006 2014 2020 2023 

Baseline emissions 103 103 107 110 ROG 

Potential reductions -- 12.9 13.5 13.7 

San Joaquin Valley 

(tons per day) 2006 2014 2020 2023 

Baseline emissions 24 26 28 30 ROG 

Potential reductions -- 3.2 3.6 3.8 

Timing 

Consumer Products Regulations 

Action: 2007-2008 

Expected Implementation: By 2010 

Action: Between 2010 and 2012 

Expected Implementation: By 2012-2014 

Staff Proposed SIP Commitment 

ARB staff proposes to commit to bring this measure to the Board by 2008. ARB 

staff will initiate a rule development process designed to achieve the reductions 

shown for the South Coast and San Joaquin Valley nonattainment areas in 2014, 

2020, and 2023. The measure as proposed by staff to the Board or adopted by 

the Board may provide more or less than the amount shown. 
April 26, 2007 131 

 Department of Pesticide Regulation’s 

Proposed SIP Commitment

The Department of Pesticide Regulation’s (DPR) proposed 2008 Pesticide Plan 

includes strategies to reduce ROG emission from pesticides through regulation of 

fumigant pesticide use, regulatory standards for registration of liquid pesticides, 

and strategic partnership agreements implementing pest management practices 

and technologies that use less pesticide product. This DPR Plan goes beyond 

reducing ozone precursor emissions by also addressing air toxic exposures 

associated with pesticide use. This proposed SIP commitment reflects only nearterm actions. Future DPR actions will be included in SIP updates after DPR 

takes regulatory action. 

Near-term Measures - Fumigant Regulations

DPR would implement regulations in 2008 that set a limit on the aggregate ROGs 

that may be emitted from field fumigation during the ozone season in the certain 

areas. In addition, the 2008 regulations would specify the allowable application 

methods that may be used in field fumigation statewide. Certain high-emission 

application methods would be excluded from that list. In 2008, emission 

reductions of 2.5 tons per day (tpd) would be achieved in the San Joaquin Valley. 

The commitment for near-term emission reductions from the 2008 regulations 

would implement the commitment for pesticide emission reductions detailed in 

the 1994 SIP in the San Joaquin Valley. 

Estimated Emission Reductions 

San Joaquin Valley 

(tons per day) 2006 2008 2014 2020 2023 

Baseline emissions 17.9 17.9 17.9 17.9 17.9 ROG Potential reductions -- 2.5 2.5 2.5 2.5 

Timing 

Action: 2008 

Expected Implementation: By 2008 

Staff Proposed SIP Commitment 

DPR staff proposes to promulgate a regulation for implementation by 2008 to 

achieve ROG emission reductions in the San Joaquin Valley in 2008 of 2.5 tpd, 

based on an inventory of 17.9 tpd.