Reducing Diesel Emissions 

in the Denver Region 

Report to the Regional Air Quality Council 

and the Air Quality Control Commission 

Diesel Stakeholders Work Group 

May 2002 
We wish to thank all the individuals who participated in the Diesel Stakeholders Work Group 

and offered their time, expertise, and assistance to this effort. 

CO-CHAIRS 

David Sladek, P.E. Douglas Lawson, Ph.D. 

Regional Air Quality Council (RAQC) Air Quality Control Commission (AQCC) 

REGULAR WORK GROUP PARTICIPANTS 

Jim Carothers Bob Farmer Lou Ha Jim Scherer 

Douglas County Citizen Regional Transportation Regional Air Quality 

District Council 

Michael Castine Kerri Fiedler 

Exhaust Repair EPA Region 8 Justin LaBoe Steve Scoma 

Tri-County Health Dept. S&S Services 

Dennis Creamer Charles Flatt 

Conoco, Inc. Cummins Rocky Mountain Doug Lempke Dan TePoel 

Air Quality Control Comm. The Emissions Clinic 

Joe Crowley Greg Fulton 

Progressive Auto Colorado Motor Carriers Robert Lowdermilk Gregg Thomas 

Performance Association Air Qualtiy Control Comm. Denver Dept. of 

Environmental Health 

Hilary Decker Brian Garber Marcy Mrozinski 

Environmental Defense Colorado Contractors DRCOG Gary Walk 

Association Douglas Co. School District 

Harry Ellison Mike Parsons 

Central Motive Power Frank Grasmugg Front Range Diesel Melissa Young 

City of Westminster Colorado Rock Products 

Association 

OTHER WORK GROUP ATTENDEES 

Karl Anderson Jeff Hajdu Robert McCormick Lucinda Smith 

Diesel Inspector Adams County NREL, formerly with City of Fort Collins 

Colorado School of Mines 

Kurt Andersen Jim lves Don Stedman 

Andersen's Foreign Car City of Aurora AI Papay University of Denver 

Service Diesel Testing Center 

Mitch Jackson Laurence Tempest 

AI Andersen FedEx Express Allen Schaeffer Douglas Co. School District 

Diesel Technology Forum 

Andersen's Foreign Car Frank Johnson Blane West 

Service Colorado Attorney Steve Sherman Colorado Diesel 

General's Office CO Dept. of Transportation 

W. Gale Biggs Bud West 

W. G. Biggs Associates Patricia Ludlow Lisa Silva Colorado Diesel 

Lockheed Martin CO Dept. of Public Health 

and Environment Gene Woodekemper John Coil 

DRCOG Randy Matsushima Arrow Stage Lines 

Valero Energy Corp. 

Jerry Gallagher 

J. Gallagher & Associates 

REGIONAL AIR QUALITY 

COUNCIL STAFF 

Ken Lloyd, 

Executive Director 

Gerald Dilley 

Misty Howell 

Sara O'Keefe 

Gary Smith 

Central Motive Power Ron Yeager 

UPS 

CO DEPT. OF PUBLIC HEALTH & ENVIRONMENT 

MOBILE SOURCES PROGRAM STAFF 

Shirleen Tucker, 

Director, Mobile Sources Program 

Michael O'Toole Doug Decker 

Mike Bywater Ray Elick 

Art Hale Ted Hollman 

Rob Livo Richard Robison 
Table of Contents 

Glossary of Abbreviations & Acronyms 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ° 0 0 0 ° 

Chapter I. Executive Summary 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1-1 

Diesel Emissions Overview 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1-1 

Work Group Overview 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1-3 

Recommendations 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1-4 

Implementation of Recommendations 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1-8 

Chapter II. Overview 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 11-1 

Current Air Quality And Emissions 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 11-1 

Estimated Diesel Contribution to PM-205, NOx, and Visibility Impairment 0 0 0 0 0 0 0 0 0 0 0 0 0 0 11-4 

Historical and Future Diesel Engine Standards 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 11-5 

Future Diesel Emissions Trends 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 11-8 

Chapter Ill. On-Road Diesel Vehicles 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 • 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 111 -1 

Overview 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 111-1 

Recommendations 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 111-1 

Chapter IV. Diesel Inspection and Maintenance 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 IV-1 

Background 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 IV-1 

Current Colorado Programs 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 • 0 • 0 0 IV-2 

Diesel 1/M Testing Procedures 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 IV-4 

Programs in Other States 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 • 0 0 0 0 IV-6 

Recommendations 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 • 0 0 0 0 0 0 0 0 0 0 0 0 • 0 0 0 0 0 0 IV-8 

Summary of Diesel 1/M Recommendations 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 • 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 IV-19 

Opacity Cutpoints 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 IV-20 

Chapter V. Off-Road Diesel Vehicles 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 V-1 

Overview 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 • 0 0 0 0 0 0 0 0 0 0 0 0 0 V-1 

Recommendations 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 V-2 

Appendix A 

National and Local Voluntary Diesel Retrofit Pilot Programs 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 A-1 
Glossary of Abbreviations & Acronyms 

APCD Air Pollution Control Division MY model year 

AQCC Air Quality Control Commission MOBILES EPA's new emissions estimation 

model 

CARB California Air Resources Board NA Naturally-aspirated (diesel engine) 

CDPHE Colorado Department of Public Health and NAAQS National Ambient Air Quality 

Environment Standards 

CMCA Colorado Motor Carriers Association NEMPPA Northeast Metro Pollution Prevention 

Alliance 

CNG compressed natural gas NFRAQS Northern Front Range Air Quality 

Study 

co Carbon monoxide NOV notice of violation 

CY calendar year NOX Oxides of nitrogen 

DFSCP Diesel Fleet Self-Certification Program OEM original equipment manufacturer 

DOIP Diesel Opacity Inspection Program PARTS EPA's mobile source particulate 

emissions model 

DR COG Denver Regional Council of Governments PM Particulate matter 

EPA Environmental Protection Agency PM-2.5 particulate matter less than 2.5 

microns in diameter 

G/BHP-HR grams per brake horsepower hour PM-10 particulate matter less than 10 microns 

in diameter 

G/Mi grams per mile PPB parts per billion 

GVWR gross vehicle weight rating PPM parts per million 

HC Hydrocarbon PSIP Periodic Smoke Inspection Program 

(California) 

HDDT heavy-duty diesel truck RAQC Regional Air Quality Council 

HDDV heavy-duty diesel vehicle RPM revolutions per minute 

1/M Inspection/Maintenance RSD Remote Sensing Device technology 

LDDT light-duty diesel truck SCR selective catalytic reduction 

LDDV light-duty diesel vehicle SIP State Implementation Plan 

LDGT light-duty gasoline truck TC turbo-charged (diesel engine) 

LDGV light-duty gasoline vehicle TPD tons per day 

VMT vehicle miles traveled 
Chapter I. Executive Summary 

Diesel Emissions Overview 

Diesel engines play Diesel engines have long been an important part of the American 

an important role in landscape and a critical part of the U.S. economy. From trucks on our 

the U.S. economy roadways to buses in our urban areas to off-road equipment in major 

construction projects, diesel engines provide a reliable, economical, and 

durable source of power for many commercial , industrial and transportation 

applications. Many parts of the nation's economy - agriculture, freight 

movement, bus transportation, construction, mining -depend on diesel 

engines to provide the necessary power and performance to get the job 

done efficiently and effectively. 

Diesel engines power 94% of all freight movement in the U.S., through 

trucks, rail, barge or tractor. Nationwide, diesel trucks haul 73% of all 

freight shipments, while in Colorado 90% of all freight manufactured in the 

state is moved by truck. 

Diesel fuel contains more energy per unit volume than gasoline. Combined 

with their more efficient combustion process, diesel engines provide for as 

much as 45-60% better fuel economy than gasoline engines. Because of 

the greater efficiency of diesel engines and greater fuel economy, diesel 

engines emit 30-35% fewer greenhouse gas emissions. 

Air quality and Despite many of the inherent advantages of diesel engines, diesel 

public health emissions have important air quality and public health implications in many 

implications urban areas around the country, including the Denver area. 

The Denver area has achieved remarkable success in improving its air 

quality and achieving EPA's health-based air quality standards. The region 

has been in compliance with EPA standards for carbon monoxide, ozone 

( 1-hour standard) and PM-1 0 for a number of years and is on the verge 

and gaining official attainment designation for all three pollutants. 

In 1997 EPA set new, tougher standards for ozone (8-hour standard) and 

fine particulate matter (PM-2.5). While the Denver region currently attains 

these standards, there is little room to spare and these standards will likely 

provide continued challenges in coming years. 

1-1 
Significant 

advances in 

diesel technology 

will reduce 

emissions 

Chapter 1: Executive Summary 

In addition, the Denver area has long been plagued by its infamous "Brown 

Cloud." The region typically exceeds the state's urban visibility standard, 

which establishes acceptable visual air quality, 50-85 days per winter 

season. 

Diesel engines are important contributors to these air quality challenges. 

While there is uncertainty to the precise contribution, diesel emissions 

contribute: 

.I 10-16% of regional primary PM-2.5 emissions 

.I 20-30% of regional NOx emissions, which contribute to 

PM-2.5, ozone and visibility impairment 

.I 15-23% of regional total PM-2.5 (primary and 

secondary) 

.I 25-40% of regional visibility impairment 

Small particles and diesel emissions have also been associated with a 

variety of public health effects, including respiratory and cardiovascular 

disease, aggravation of existing asthma, acute respiratory illnesses, 

chronic bronchitis, decreased lung function and even premature death and 

other toxic effects. The effect on children, the elderly and those with 

preexisting illnesses is of particular concern. In addition, EPA has 

classified diesel emissions as a "likely" human carcinogen. 

See Chapter II for more detailed information on air quality impacts of diesel 

emissions. 

Over the last decade, there have been significant improvements in diesel 

technology that have resulted in significant reductions in emissions from 

new diesel engines. Improvements in engine design, after-treatment 

technology , and diesel fuel have all contributed to improved emission 

performance. The Diesel Technology Forum estimates that total emissions 

of PM and NOx from diesel engines have been reduced by 25-35% through 

the 1990s. 

Even more dramatic improvements in diesel technology will result in 

significant emissions reductions when new on-road engine standards take 

effect in 2004. In 2007, even tighter new engine standards, coupled with 

the introduction of ultra-low sulfur diesel fuel , will reduce emissions of PM 

and NOx by more than 90% for new engines. 

EPA also set tighter emission standards for off-road diesel engines in 1998 

and expects to propose more stringent standards in the near future that will 

take effect later this decade. 

While these new standards for on-road and off-road engines are 

significant, they will not have an immediate effect. Since diesel engines 

are very durable 

1-2 
Chapter 1: Executive Summary 

and remain in operation for many years, it take many years to realize the 

full impact of these new standards as the diesel fleet gradually turns over. 

Nonetheless, significant opportunities exist to introduce new technology 

into the in-use fleet and take advantage of these emission reduction gains 

sooner. 

See Chapter II for more detailed information on new diesel engine 

standards and diesel emission trends. 

Work Group Overview 

Colorado first established a diesel emissions program in the mid-1980's. A 

diesel inspection/maintenance program resulted from the Governor's BlueRibbon Diesel Task Force in 1987 and has remained in operation, 

essentially unchanged, even since. 

The Regional Air Quality Council, the Denver region's lead agency for air 

quality planning, and Colorado Air Quality Control Commission both have 

an interest in the effective control of diesel emissions, not only along the 

Front Range but throughout Colorado. Concern over the potential impact 

of diesel emissions, coupled with recognition of recent and future advances 

in diesel engine technology, led the RAQC and AQCC to form a joint Diesel 

Stakeholders Work Group in August 2001 . The RAQC and AQCC charged 

the Work Group with four primary tasks: 

./ Determine the impact of diesel emissions on Denver area air 

quality and assess the impact of future programs; 

./ Review the current Diesel Inspection/Maintenance Program 

and recommend improvements to make the program more 

efficient and effective; 

Explore opportunities and incentives for advancing clean 

diesel technology and other emission reduction techniques in 

the marketplace sooner; 

Assess contribution of off-road diesel engines and 

recommend opportunities for emission reductions. 

The Work Group was open to all interested parties. Participants included 

representatives from the trucking industry, public and private fleet 

operators, engine manufacturers, oil companies, emission testing 

operators, state and local governments, and environmental organizations. 

1-3 
On-Road Diesel 

Vehicles 

Chapter 1: Executive Summary 

The Work Group met 10 times between October 2001 and May 2002 to 

hear relevant presentations on diesel topics and discuss the issues. 

Presentations were made by a number of interested and knowledgeable 

groups: 

P Regional Air Quality Council P CO Dept. of Public Health and 

P Colorado Motor Carriers Association Environment, Air Pollution Control 

P Diesel Technology Forum Division 

P Colorado Institute for Fuels and P Northeast Metro Pollution Prevention 

Engine Research Partnership 

P Colorado Contractors Association P Cummins Engine Rocky Mountain 

P Environmental Defense P Wagner Equipment Co. 

P Colorado Diesel Emissions Inspection P ldleAire Corp. 

and Maintenance Assoc. P EPA Voluntary Diesel Retrofit 

P California Air Resources Board Program 

Recommendations 

The Work Group is pleased to present the result of its review of diesel 

issues in the Denver region and offers recommendations for consideration 

by the Regional Air Quality Council and Air Quality Control Commission. 

While every Work Group member may not necessarily agree with every 

recommendation, the recommendations and conclusions presented in this 

report represent the strong consensus of the Work Group. Likewise, some 

members may feel strongly about some issues that they feel are not 

addressed adequately in the report. Even though most agree more work 

needs to be done, this report represents a solid starting point for 

addressing diesel issues and programs. 

Members of the Work Group stand ready to assist the RAQC, AQCC, 

Colorado Department of Health and Environment, the Governor's office, 

and the General Assembly with implementing these recommendations. 

See Chapter Ill for more detail and background on these recommendations 

#1 Fleet outreach and awareness program 

Establish a Fleet Outreach and Awareness Program to encourage 

voluntary initiatives by fleet operators to reduce diesel emissions from the 

current in-use fleet. This program could result in significant emissions 

reductions well in advance of new federal engine and fuel standards 

1-4 
Chapter 1: Executive Summary 

The program would launch a significant outreach and awareness effort with 

private and public fleets in the Denver region and recognize fleet operators 

that undertake voluntary programs to reduce emissions from their fleet of 

diesel vehicles. Outreach to fleet operators would be accomplished 

through development and distribution of written information, workshops and 

training seminars, one-on-one visits , and awards programs. The program 

would include elements outlined below. 

#2 Fleet recognition program 

Provide public recognition of voluntary efforts by fleet operators to reduce 

emissions as an incentive to consider programs that will benefit public 

health and air quality. 

#3 Best practices program for vehicle maintenance 

Encourage fleets to utilize best practices for vehicle maintenance by 

working with the Northeast Metro Pollution Prevention Alliance (NEMPPA) 

to expand NEMPPA's best practices maintenance program region wide. 

#4 Strategies to reduce vehicle idling 

Work with industry experts to develop and distribute educational materials, 

conduct workshops, and implement pilot projects on measures to reduce 

idling and the economic and environmental benefits that could be derived. 

#5 Accelerated vehicle retirement, retrofit, and alternative fuel projects 

Work with fleet operators, engine manufacturers, fuel suppliers, and others 

to encourage early introduction of advanced diesel technology in in-use 

fleets, including accelerated engine replacement, retrofits , and cleaner 

fuels. 

#6 Diesel fleet survey 

Conduct a survey of public and private fleets in the region to determine the 

current composition of diesel vehicles in the area and to identify those 

fleets with innovative programs to reduce emissions. 

#7 Clearinghouse of incentive programs and emission requirements 

Establish a web-based information clearinghouse to serve as a central 

repository locally where companies and potential users may quickly find 

current and accurate information relating to emission requirements, new 

technology, and potential incentives at the state and federal level to reduce 

emissions. 

1-5 
Diesel 

Inspection/ 

Maintenance 

Program 

#1 

Chapter 1: Executive Summary 

See Chapter IV for more detail and background on these recommendations 

Evaluation of program effectiveness 

Review the Diesel Inspection/Maintenance program within the next two 

years to determine if further improvements are necessary and feasible. 

Develop a research protocol and necessary funding to conduct periodic 

evaluations of program effectiveness. Identify further specific information 

and data needs and questions that need to be answered. 

#2 Automated data reporting 

Automate data reporting and analysis and develop an internet-based 

system for information exchange. 

#3 On-road enforcement 

Add an on-road enforcement element to the program, either through 

remote sensing, smoking vehicle hotlines, or limited roadside pullovers 

(based on probable cause). 

#4 Weight definition 

Define heavy-duty diesel vehicles as those greater than 14,000 pounds 

gross vehicle weight (GVWR) and eliminate the reference to empty weight 

or curb weight in Regulation No. 12. 

#5 Model year exemptions and biennial testing 

Increase model year exemptions to four years for heavy-duty diesel 

vehicles and decrease test frequency to biennial testing for HDDV 10 

model years and newer (beginning with MY 1995) under both programs. 

#6 Testing of vehicles operating in area 

Modify state statute to require testing of all diesel vehicles routinely 

operated in the program area, not just those registered , required to be 

registered or housed in the program area as currently required. 

#7 Testing protocols 

Maintain current testing protocols with the following changes: 

- allow SAE J1667 (or other future automated testing protocol) as an 

option for all HDDV 10 model years and newer in the fleet program; 

- require lug down test for all HDDV older than 10 model years in both 

programs; and 

- eliminate visual testing , during a two-year phase in period, as an 

option for all HDDV in the fleet program older than 10 model years. 

1-6 
Chapter 1: Executive Summary 

#8 Emissions-based testing 

Since opacity is not a good measure of emissions for newer technology 

vehicles, Colorado should work in a joint effort with the Environmental 

Protection Agency (EPA) and other states to conduct research and pilot 

studies to develop appropriate emissions-based testing methods for future 

consideration . 

#9 Focus audit program 

Improve audit program by focusing on HDDV fleets with higher than normal 

out-of-service ratings or fail rates. 

#1 0 Technician training 

Expand repair technician training and technical assistance similar to the 

efforts for the gasoline vehicle program. 

#11 Clean screen remote sensing 

Investigate using remote sensing technology to clean screen light-duty 

diesel vehicles and identify high-emitting vehicles. 

#12 Repair cost waiver 

Off-Road Diesel 

Vehicles 

Eliminate or increase the current repair cost waiver for failed diesel 

vehicles. 

See Chapter V for more detail and background on these recommendations. 

#1 Fleet Outreach and A ware ness Program 

Include off-road fleets and engines in the fleet outreach, awareness and 

recognition program to encourage voluntary initiatives by fleet and engine 

operators to reduce diesel emissions from the current in-use equipment. 

#2 Use of low-sulfur fuel 

Improve the understanding of the current use of low sulfur fuel (500 ppm) 

and the population of off road diesel equipment in the Denver metro area. 

#3 Incentives to encourage use of low-emitting fuels 

Based on the need, investigate incentives to encourage the use of low 

sulfur fuel (500 ppm) and other low emitting fuels and investigate the 

possibilities of early introduction of ultra-low sulfur fuels (15 ppm). 

#4 Best management practices 

Encourage best management practices regarding engine maintenance, 

idling and use. 

#5 Programs for large-scale construction projects 

Encourage low-emitting fuels, retrofits and other low-emitting technology in 

large-scale construction projects. 

1-7 
Colorado 

General 

Assembly 

Chapter 1: Executive Summary 

Implementation of Recommendations 

Implementation of the Work Group's recommendations will take a 

concerted and coordinated effort by a number of parties. Effective 

implementation will involve many parties, including CDPHE, AQCC, RAQC, 

the General Assembly, local governments, industry groups, fleet operators, 

and engine manufacturers. 

Specific implementation steps and responsibilities are addressed for each 

recommendation in Chapter Ill, IV, and V. The following list summarizes 

the implementation responsibilities (with a reference to each 

recommendation #). 

The Work Group recommends the Regional Air Quality Council coordinate 

the implementation of the recommendations. While the RAQC is not 

responsible for directly implementing many of the recommendations, the 

Work Group members believed the RAQC should be the organization 

responsible for facilitating the implementation of the recommendations and 

bringing the various parties together. 

Dieseii/M Program 

P Authorize effective on-road identification and enforcement 

program (#3) 

P Redefine HDDV/LDDV weight classification (#4) 

P Increase model year exemptions and authorize biennial testing 

for newer HDDV (#5) 

P Require testing of diesel vehicles that routinely operate in the 

program area (#6) 

P Allow SAE J1667 or other automated testing for newer fleet 

vehicles (#7) 

P Authorize clean screen remote sensing for LDDV (#11) 

P Eliminate or increase current repair cost waiver (#12) 

P Provide adequate funding for periodic evaluation of program 

effectiveness, automated data reporting, fleet audits, and 

technician training (#1,2,9, 10) 

Fleet Outreach and Awareness Program 

P Provide funding or tax incentives for upgrading and modernizing 

equipment through accelerated engine replacements, retrofits, 

or clean fuel use (#5) 

1-8 
Colorado 

Department of 

Public Health 

and 

Environment 

Chapter 1: Executive Summary 

Off-Road Vehicles 

P Provide funding or tax incentives for upgrading and modernizing 

equipment through accelerated engine replacements, retrofits, 

or clean fuel use (#1,3) 

P Require or encourage large state-sponsored construction 

contracts to include specifications for upgrading and 

modernizing equipment through clean engine requirements, 

retrofits, or clean fuel use (#5) 

Diesel liM Program 

P Develop program evaluation protocol and seek appropriation for 

necessary funding (#1) 

P Develop automated data reporting system with Department of 

Revenue and seek appropriation for necessary funding (#2) 

P Evaluate on-road identification and enforcement approaches for 

consideration by General Assembly (#3) 

P Participate in national efforts to evaluate emissions-based 

testing methods (#8) 

P Implement procedures to improve fleet audit program and seek 

appropriation for additional funding if necessary (#9) 

P Expand repair technician training and technical assistance 

program and seek appropriation for additional funding if 

necessary (#10) 

P Evaluate feasibility of remote sensing clean screen program for 

LDDV (#11) 

Fleet Outreach and Awareness Program 

P Provide technical assistance and possibly grant support to 

Green Fleets program (#1-7) 

Off-Road Vehicles 

P Provide technical assistance and possibly grant support to 

Green Fleets program as it relates to off-road fleets (#1-4) 

P Encourage state agencies to consider, in large state-sponsored 

construction contracts, specifications for upgrading and 

modernizing equipment through clean engine requirements, 

retrofits , or clean fuel use (#5) 

1-9 
Air Quality 

Control 

Commission 

Regional Air 

Quality Council 

Chapter 1: Executive Summary 

Diesel 1/M Program (Revisions to Regulation 12) 

P Conduct an annual review of the Diesel 1/M program (#1) 

P Define and require compliance with automated data reporting 

(#2) 

P Eliminate visual testing, during a two-year phase in period, as an 

option for all HDDV in the fleet program older than 10 model 

years (#7) 

P Promulgate regulation revisions for items enacted by General 

Assembly (#1-7, 11, 12) 

Fleet Outreach and Awareness Program 

P Provide recognition for exemplary fleets under fleet recognition 

program (#2) 

Off-Road Vehicles 

P Encourage state agencies to consider, in large state-sponsored 

construction contracts, specifications for upgrading and 

modernizing equipment through clean engine requirements, 

retrofits, or clean fuel use (#5) 

Overall 

p Coordinate implementation of Work Group recommendations 

endorsed by RAQC and AQCC (all) 

Dieseii/M Program 

P Publicize review by Work Group and recommendations 

endorsed by RAQC and AQCC (all) 

P Assist CDPHE, AQCC, and General Assembly, as necessary, 

with evaluating implementing recommendations (all) 

Fleet Outreach and Awareness Program 

P Take the lead in working with other program sponsors and 

supporters to establish and implement the Fleet Outreach and 

Awareness Program (#1-7) 

P Coordinate fleet recognition program (#2) 

P Develop materials and outreach approaches for program (#1-7) 

P Establish a web-based information clearinghouse (#7) 

P Seek necessary funding from grants and private contributions to 

implement the Fleet Outreach and Awareness Program and 

associated pilot projects (#1-7) 

1-10 
Chapter 1: Executive Summary 

Off-Road Vehicles 

P Take the lead in working with other program sponsors and 

supporters to establish and implement the Fleet Outreach and 

Awareness Program, which includes off-road fleets (#1-4) 

P Work with industry associations to determine the use of lowsulfur diesel fuel and the population off-road diesel equipment in 

the Denver metro area (#2) 

P Encourage local governments and private develops to consider, 

in large-scale construction projects, specifications for upgrading 

and modernizing equipment through clean engine requirements, 

retrofits, or clean fuel use (#5) 

1-11 
Chapter II. Overview 

Current Air Quality And Emissions 

Due to considerable local effort in woodburning , street sanding/sweeping, 

industrial source control regulation and inspection/maintenance programs 

for gas vehicles and federal standards the Denver metro area is currently 

in attainment for all federal air quality standards. At this time, it appears 

that the area will most likely attain the new federal 8-hour ozone and PM2.5 standards. The State Visibility Standard is 

consistently exceeded 50-85 times each winter season. 

Denver Area Air Quality Status 

Existing federal The Denver area is currently attaining all federal air quality standards, 

standards including carbon monoxide (CO), PM-1 0, and one-hour ozone. 

The Denver area achieved official attainment redesignation status from 

EPA for one-hour ozone in October 2001 and carbon monoxide in 

effective January 2002. 

The attainment redesignation request for PM-1 0 is pending before the 

Environmental Protection Agency (EPA), which plans to propose approval 

of the region's plan and request shortly. 

New federal The Denver area currently attains EPA's new 8-hour ozone standard, but 

standards by only a small margin (less than five percent). In 1998, the Denver area 

recorded elevated levels of ozone throughout the region, jeopardizing the 

area's continued attainment of the standard. However, during the last 

three summers (1999-2001 ), ozone readings returned to normal levels. 

Though the 8-hour standard is 80 ppb, violation of the standard occurs 

when a three-year rolling average of the 4th maximum readings at a 

monitor in the region is equal or greater than 85 ppb. 

8-hour Ozone The following chart presents the annual 4 th maximum readings of the two 

(of eight) monitors (NREL and Rocky Flats) each with the current (1999-

2001) highest 3 year average of 81 ppb. 

11-1 
100 

90 

80 

70 

60 

50 

40 

30 

20 

1 0 

0 

Chapter II: Overview 

- l 

4th Maximum Ozone Levels (ppb) I 

~------~ ----------~~, .U= ..,- ~ 

- "' ~ \ l 

""' \3 year average 0 f 4th max 

"" = 85 ppb =violation I 

"" "-so ppb 8 - Hour Ozone Standard 

1996 1997 1998 1999 2000 2001 

1-+--NREL - Ro cky F lat s I L_------------~==========~========~--------J 

PM-2.5 PM-2.5 monitoring using EPA's new federal reference method only began 

in 1999 and therefore a complete, fully representative set of data from the 

7 monitoring sites is not available to judge the Denver area's ultimate 

attainment status. 

Violation of the 24-hour standard occurs when the 3 year average of the 

71

h maximum is 65 ug/m3 or greater. The current 3 year average (1999-

2001) of the 51

h maximum readings at CAMP is 33 ug/m3

. The maximum 

24-Hour PM-2.5 levels at CAMP are presented in the following chart. 

80 

70 

60 

50 

40 

30 

20 

10 

0 

Maximum 24-Hour PM2.5 (ug/m3) 

CAMP-21 05 Broadway 

~ 

65 ug/m3 - 24-Hour Standard / ./'. 

- ...c> 

/ 

~ 

.-A 

v ------ "' 

1999 2000 2001 

-l 

-

---

-

-

~ 1st Max ----- 2nd Max ----..- 3rd Max 4th Max ~ 5th Max 

11 -2 
Chapter II: Overview 

Violation of the annual standard occurs when the 3 year average of the 

annual averages of a monitor is 15 ug/m3 or greater. The current 3 year 

average (1999-2001) of the annual average readings at Adams City is 

11 .5 ug/m3

. The annual average PM-2.5 levels at Adams City and CAMP 

are presented in the following chart. 

Annual Average PM2.5 ug/m3 

20 ,-----------------------------------------, ¥" 15 ug/m3- Annual Average Standard 

15 +---~----------------------------~~~r-----~ 

10 +---~~~~==~====== ----­ ......-

5 +------------------------------------------

0 +-------------,-------------,-------------~ 

1999 2000 2001 

!-+-Adams City -t~- CAMP 

State visibility In 1990 the Colorado Air Quality Control Commission (AQCC) established 

standard an urban visibility standard (0.076/km) to serve as a goal and a measure 

of visual air quality (i.e., the Brown Cloud). The Denver area typically 

exceeds the visibility standard during 50-85 days per winter season, with 

10-20 of those days in the extremely poor category (greater than twice the 

standard). 

Visibility Standard Exceedances 100 ~-----------------------------------, 

80 +------- ----------------------~ 

60 +-~~ -------- -- L---------~ ~ 

40 +-----------------------------------~ 

20 ~-~~._~~~~~~~----~~ 

0 +-~--~--~~--~--~~--~--~~--~~ 

"!), ~ b< ~ !0 ~ ~ ~~ "!), ';!)~ ...... ~ n~ ~OJ ~Oj ~Oj !()~ ~9) ~Oj SS ';!)~ ...... ~ Oj ~ ~ ~ OJ Oj Oj ~ OJ ~ ~ ~ 

I ~ Exceedance Days - Extremely Poor Days I 

* Monitoring Equipment out of service for repair at this time. 

11-3 
Chapter II : Overview 

Estimated Diesel Contribution 

to PM-2.5, NOx, and Visibility Impairment 

Diesel emissions contribute to both PM and NOx. The following presents 

a range of potential diesel contribution to the total PM-2.5 and NOx for all 

sources, based on different analytical approaches: 

NO/ Primary Sec. Total PM- Visibility 

PM-2.5* PM-2.5* 2.5* 

On-road 10-15% 3-12% 3% 10-15% 15-25% 

diesel 

Off-road 10-15% 3-5% 2-4% 5-8% 10-15% 

diesel 

Total 20-30% 10-16% 5-7% 15-23% 25-40% 

diesel 

*Expressed in percent of total PM-2.5 and NOx from all sources. Totals for 

primary PM-2.5 do not add since the ranges come from different sources. 

Range of diesel contribution estimates come from a variety of local and 

national sources based on different analytical approaches. The on-road 

diesel contribution is approximately 97% heavy-duty diesel vehicle (HDDV) 

and 3% light-duty diesel vehicle (LDDV) emissions. Considerable 

uncertainty exists on the total diesel contribution and the relative 

contribution of on-road and off-road sources, but the ranges capture the 

uncertainty. 

The lower end of the ranges for primary PM-2.5 come from the 1998 

Northern Front Range Air Quality Study (NFRAQS), which was a PM-2.5 

apportionment study that based its estimates on emission factors derived 

for the study, ambient measurements of various components, and 

chemical mass balance modeling. NFRAQS concluded that diesel engine 

emissions contribute approximately 15% to total PM-2.5 (primary and 

secondary) while gasoline engine emissions contribute approximately 38% 

to total PM-2.5. 

The higher end of the ranges come from local and/or national emission 

inventories. Local inventories are based on NFRAQS emission factors for 

diesel vehicles, local diesel fuel usage, and local activity factor estimates. 

The local/national inventory data suggest that diesel engine emissions 

contribute approximately 23% to total PM-2.5 while gasoline engine 

emissions contribute approximately 15% to total PM-2.5. 

11-4 
Historical Certified 

Emissions Standards 

Chapter II : Overview 

Secondary PM-2.5 estimates are further derived from NOx emission 

inventory estimates and NFRAQS measurements of ammonium nitrate. 

Under stagnant inversion conditions, the contribution to secondary PM-2.5 

from gasoline and diesel vehicles may in fact be higher since mobile NOx 

emissions will contribute disproportionately to ground-level nitrate 

concentrations. 

Estimates of potential visibility impairment are based on light extinction 

coefficients for various compounds. Primary diesel emissions are 

composed of about 80% elemental carbon, which has the greatest light 

extinction efficiency and about double the contribution of nitrate and 

organic mass and about 10-20 times greater than dust or other coarse 

particles. 

Diesel vehicles and equipment are relatively insignificant contributors to 

carbon monoxide (CO), hydrocarbons (HC) and total PM-10 (3% or less). 

Historical and Future Diesel Engine Standards 

On-Road Heavy Duty Diesel Emissions Standards 

1970-85 - Emissions standards for heavy-duty diesel engines were 

introduced in 1970 with a 13 mode steady-state test procedure which 

continued through the 1983 model year. In 197 4 HC+NOx and CO 

standards were introduced. Additionally, opacity smoke standards were 

tightened to levels (Accel=20%, Lug=15% and Peak=50%) which are 

current today. The first NOx emissions standard (10.7 g/bhp-hr) and an 

optional transient test were added in 1984. The steady state test was 

eliminated in 1985. 

1988-98 -A PM standard (0.6 g/bhp-hr) was added in 1988 and PM and 

NOx standards continued to be tightened (6.0 g/bhp-hr) in 1990 and 5.0 

g/bhp-hr in 1991) to their current levels (4.0 g/bhp-hr in 1998) through this 

period as shown in the chart on the following page. Technological 

changes began in 1990 with turbocharging , retarded fuel injection timing , 

etc., initial use of electronic controls started in 1991 and was used on most 

engines by 1994 and nearly all engines by 1998. Oxidation catalysts and 

improvements to combustion chamber design were introduced in 1994. 

Further improvements in turbocharging continued through 1998. 

Future Certified 2002-04 - In 2004 a NOx + HC standard of 2.5 g/bhp-hr, with a HC limit of 

Emissions Standards 0.5 g/bhp-hr was introduced. In a Consent Decree with the federal 

government, six engine manufacturers agreed to produce engines 

meeting the 2004 standard by October 2002. 

11-5 
Chapter II : Overview 

2007 - The emissions standards for PM and NOx continue to be lowered 

in 2007 to 0.01 g/bhp-hr for PM and 0.20 g/bhp-hr for NOx as shown on 

the following chart. To achieve 2007 standards an ultra-low sulfur fuel 

(sulfur 

content 15 ppm) is required . Also, technology to achieve the 2007 

standards includes catalyzed traps, oxidation catalysts, NOx absorbers, 

and selective catalytic reduction systems. 

7.0 

-.::- 6.0 .s::. 6.. 5.0 

:§ 4.0 

:§ 3.0 

>< 2.0 

0 

z 1.0 

0.0 

"" 1 

On-Highway Heavy Duty Diesel Engine 

Emissions Standards 

"\ ... r+- ~ 1\. - - 1\. 1- - "\ 

~ - 1990 1993 1996 1999 2002 2005 2008 

[- Nox -+-PM [ 

On-Road Light-Duty Diesel Emissions Standards 

~ 

0.7 

0.6-.::-

0.5 -'r 

0.4 _g. 

.c 0.3 c, 

0.2 i 

0.1 a.. 

0 

Tier 1 Standards Light-duty diesel vehicles (LOOV) and light-duty diesel trucks (LOOT) 

(promulgated 1990) through 2003 require a 1.0 gram/mile (g/m) NOx standard. By contrast 

gasoline fueled vehicles were required to meet a 0.6 g/mi (light-duty gas 

vehicle (LOGV) & light light-duty gas trucks (Light LOGT) and 1.53 g/mi 

(Heavy LOGT) NOx standard in 1994. In 1999 NOX standards were 

further lowered for 0.3 g/mi (LOGV), 0.5 g/mi (Light LOGT). 

Particulate standards of 0.10-0.12 g/m applicable to all light-duty cars and 

trucks were set to accommodate diesel engine technology . At the time 

diesel vehicle could just make the standard , while gasoline-fueled vehicles 

could easily achieve 0.01 g/mi. 

Tier 2 Standards All light-duty cars and trucks, including the heavier, light-duty trucks, and 

(promulgated 1999) regardless of fuel will be required to achieve the same standards during a 

phase-in period beginning in 2004 and ending in 2009. 

The light-duty cars and trucks will begin phase in (25% per year) to meet a 

0.07 g/mi NOx standard in 2004. The heavier light-duty trucks will begin 

phase in (50% per year) to meet a 0.07 g/m NOx standard in 2008. 

11 -6 
Tier 1 Standards 

(promulgated 1994) 

Chapter II : Overview 

During phase in those vehicles not meeting the ultimate standard will meet 

an interim standard. The light-duty cars and trucks will meet an average 

0.3 g/mi interim NOx standard. The heavier light-duty trucks will meet an 

average 0.2 g/mi interim NOx standard beginning in 2004. 

The light-duty cars and trucks will meet a PM standard 0.01 to 0.02 g/mi in 

2004 depending on the "bin" selection of the manufacturer. Particulate 

standards for the heavier light-duty trucks will be in the range of 0.08 to 

0.06 g/mi from 2004 until 2006. Ultimately by 2007 the PM standard of 

0.01 to g/mi is required . 

Off-Road Heavy-duty Diesel Emissions Standards 

Tier 1 Standards for off-road engines were established in 1994 and began 

to be phased in for various horsepower ratings in 1996 through 2000. As 

shown in the following table, Tier 1 standards will remain in effect until the 

Tier 2 and/or Tier 3 standards take effect. 

Tier 2 and Tier 3 Tier 2 and Tier 3 standards were established in 1998 to be phased in for 

Standards various horsepower ratings between 2001 and 2008 as shown in the 

(promulgated 1998) following table. 

HP 

<11 

11<25 

2.5<3) 

fD<100 

100<175 

175<m 

n><aX) 

Em< ?ED 

>?ED 

Off-Road Heavy-Duty Engines 

NOx+HC and PM Emissions Standards (g/bhp-hr) 

(NOx + HC I PM) 

200)1200112002 2003 2004 2005 2003l200712lm 

7.8/Q75 5.610.60 

7.1/Q60 5.610.60 

7.1/Q60 5.610.45 

7.610.72 5.610.30 I 3.5/-

7.3/0.40 4.9/0.22 I 3.0/-

7.3/0.40 4.910.15 3.0/-

7.3/0AOI 4.8/Q15 3.0/-

7.3/0.40 I 4.8/Q15 3.0/-

NA/0.40 4.8/Q15 

11-7 
Chapter II : Overview 

Off-Road Fuel Current off-road fuel standards allow 5000 ppm in sulfur content. Work 

Standards group discussion indicates that most public works and private construction 

companies are using fuel with 500 ppm sulfur content in off-road 

equipment. 

Unlike the current (2006-07) on-road standards that call for a reduction in 

fuel sulfur content (from 500 ppm to 15 ppm) to help meet stringent new 

engine standards, the current Tier 2 & 3 off-road standards do not 

incorporate lowered fuel sulfur content standards. Tier 2 & 3 standards 

are well above the established on-road standards for the same 2006-07 

time frame . 

Future Diesel Emissions Trends 

On-Road PM Baseline diesel primary PM-2.5 emissions for on-road for the Denver 

metro area have been taken from the 1995 inventories developed by the 

RAQC for the Blueprint for Clean Air planning process ( 1996-98). The 

trend curves however start at the year 2000 since at that time monitored 

emissions indicated attainment of the PM standards. Emissions were 

based on emissions factors developed during testing of 33 HDDV 

operating in the metro area for the Northern Front Range Air Quality 

Study, 1998 and Denver Regional Council of Governments (DRCOG) 

vehicle miles traveled (VMT) estimates. 

Trends in future on-road emissions were developed using certified 

emissions factors and diesel VMT mix over time from MOBILE6.1 support 

data and VMT growth rates from the recent PM-10 Maintenance Plan, 

2001 . 

MOBILE6.1 national data indicate approximately 70% of the VMT is 

caused by vehicles in the first 10 MY, while the remaining 30% of the VMT 

is caused by vehicles in the 11 th through 30th model year (MY). Data from 

the Air Pollution Control Division (APCD) and the Colorado Motor Carriers 

Association (CMCA) indicates that the Denver metro area may have a 

67%/33% split in VMT. Additionally, difficult economic times for the 

trucking industry slowing the purchase of newer vehicles was analyzed by 

assuming 50% of the VMT was produced by the first 10 MY and 50% 

produced by the 11 th through 30th MY. The trends are presented in the 

following chart. 

11-8 
Chapter II: Overview 

PM-2.5 Emissions Trend- tons per day 

2000 2005 2010 2015 2020 

1- - 50% VMT/1 st 10 MY -··-·-. National -Denver I 

On-Road NOx Baseline diesel NOx emissions for on-road for the Denver metro area in 

1995 are based on a recent analysis of MOBILE6.0 by the APCD using 

certified NOx emissions factors and DRCOG VMT estimates. 

Trends in on-road emissions were developed using certified emissions 

factors and diesel VMT mix over time from MOBILE6.0 support data and 

VMT growth rates from the recent PM-1 0 Maintenance Plan, 2001. 

As discussed above for PM, NOx emissions trends based on the EPA 

national data, Denver metro data and an assumed hardship condition in 

the trucking industry slowing the rate of newer vehicles entering the fleet 

are presented in the following chart. 

NOx Emissions Trend- Tons per day 

,-------------------------------------------~ 

0 +--------.--------.--------,,-------~------~ 

2000 2005 2010 2015 2020 

--50% VMT/1 st 1 0 MY ·- ·- · · · National -Denver 

11 -9 
Chapter II: Overview 

Off-Road PM The 1995 baseline PM and NOx emissions are consistent with inventories 

and NOx from the Blueprint for Clean Air planning process, which are based on the 

20 Cities Study, EPA, 1990. The trend curves start with the year 2000 

since the region was attaining all NAAQS at that time. 

The trends for construction, industrial and rail are based on population, 

activity and certified emissions factors developed from the EPA Non Road 

Model by the APCD for the recent PM-1 0 Maintenance Plan, 2001 . 

The trends for PM and NOx are presented in the following charts. 

Off-road Diesel NOx Emissions Trends 

EPA Non-road Model 

Metro Area 

2000 2005 2010 2015 

l oconstruction •Industrial ORail l 

Off-road Diesel PM Emissions Trends 

EPA Non-road Model 

1 .8 

1 .6 

a.. 1 .2 

!::.. 1 .0 0 0 .8 

i 0 .6 

a.. 0.4 

0 .2 

0 .0 

Metro Area 

2000 2005 2010 2015 

I 0 Construction •' ndustrial o Rail 

11-10 
Chapter Ill. On-Road Diesel Vehicles 

Establish a Fleet 

Outreach and 

Awareness Program 

Overview 

As indicated earlier, significant advances in diesel engine technology 

have led to considerable reductions in diesel emissions over the last two 

decades. Diesel engine manufacturers and fuel suppliers have worked 

together to dramatically reduce emissions from diesel engines while at 

the same time improving reliability, durability, and fuel efficiency. Tighter 

future standards for new diesel engines will continue to reduce emissions 

over the next 10-20 years. 

Despite these gains, the turnover of the diesel fleet to cleaner engines 

can take many years because of the durability and long road life of diesel 

engines. There are still opportunities to reduce emissions from the in-use 

fleet through proper maintenance, reductions in vehicle idling, 

accelerated vehicle retirement, add-on equipment retrofits, and use of 

cleaner diesel fuels. 

Fleet operators in many areas of the country are currently implementing a 

variety of programs to introduce new technology sooner and reduce 

diesel emissions. EPA has established a national Voluntary Diesel 

Retrofit Program to help build partnerships among industry, community 

groups, and state and local officials to implement retrofit projects that 

result in cleaner, healthier air for their communities. The Diesel 

Technology Forum, an organization of diesel engine and emission control 

manufacturers and petroleum refiners, has also been an active promoter 

of the concept of retrofitting existing diesel engines to reduce emissions 

as a cornerstone of the Forum's overall program to advance clean diesel 

technology. 

Recommendations 

To take advantage of these opportunities to reduce diesel emissions in 

innovative ways, establish a Fleet Outreach and Awareness Program 

to encourage voluntary initiatives by fleet operations to reduce diesel 

emissions from the current in-use fleet. 

111-1 
Chapter Ill: On-Road Diesel Vehicles 

The Fleet Outreach and Awareness Program would launch a 

significant outreach and awareness effort with private and public fleets in 

the Denver region and recognize fleet operators that undertake voluntary 

programs to reduce emissions from their fleet of diesel vehicles. 

Outreach to fleet operators would be accomplished through development 

and distribution of written information, workshops and training seminars, 

one-on-one visits, and awards programs. The Fleet Outreach and 

Awareness Program would include elements outlined below. 

Fleet Recognition Many fleets operators nationally and in the Denver area are implementing 

Program or planning a variety of voluntary programs to reduce emissions from their 

existing diesel fleet. Public recognition of these efforts can give fleet 

operators an incentive to consider programs that will benefit public health 

and air quality. 

Implementation: A special recognition program would be established to 

highlight public and private fleets and supporting companies that have 

undertaken significant voluntary efforts to reduce diesel vehicle 

emissions. Criteria would be established for recognition and nominations 

will be solicited for judging by an independent panel. 

Exemplary fleets would be recognized at a special ceremony with an 

award and would be allowed to display a program logo. Fleets would also 

be recognized through advertising, media placements, on appropriate 

web sites, and in promotional materials. 

The fleet recognition program would be a cooperative effort of the 

Governor's Office, the Regional Air Quality Council (RAQC), the Colorado 

Department of Public Health and Environment (CDPHE), the Colorado 

Motor Carriers Association (CMCA), and other sponsoring organizations. 

Best Practices Well-maintained diesel vehicles produce less pollution than vehicles that 

Program for Vehicle are not rigorously maintained. By implementing best practices for vehicle 

Maintenance maintenance, fleet operators not only will reduce vehicle emissions but 

will also reduce operating and long-term maintenance costs. 

Implementation: Building upon a program initiated by the Northeast 

Metro Pollution Prevention Alliance (NEMPPA), the Fleet Outreach and 

Awareness Program will assist with expanding the best practices 

maintenance program region wide. Using NEMPPA's Best Practices 

Manual, the outreach effort will assist companies and truck owners in 

developing an effective vehicle maintenance program that will reduce 

diesel emissions. Particular attention will be given to individual truck 

owners and 

111-2 
Chapter Ill: On-Road Diesel Vehicles 

smaller fleets who do not possess the expertise or resources associated 

with maintaining vehicles in optimal running order. The effort will also be 

coordinated with CDPHE's training program for repair technicians. 

Strategies to Reduce One area where significant emission reductions can be realized is in the 

Vehicle Idling area of excessive vehicle idling. Advances in engine technology and 

other types of technology makes excessive vehicle idling unnecessary 

and costly to the truck owner. 

Excessive engine idling increases fuels costs, maintenance costs and 

engine wear for truck owners. According to information provided by 

Cummins Rocky Mountain, engine idling costs a truck owner $0.75-1 .12 

per hour, or $4.50-6.75 per day in wasted fuel, and can result in two 

additional oil maintenance intervals per year at a cost of at least $200. In 

addition, since oil additive packages tend to degrade more quickly during 

idling, excessive idling will tend to accelerate the accepted normal rate of 

engine wear. 

There are several strategies that can be employed to reduce vehicle 

idling. One of the first steps is greater education on the economic and 

environmental impacts of excessive idling. There are also engine control 

systems that monitor and control the idling of engines while maintaining 

block temperature, battery voltage and/or cab temperature. In addition, 

truck owners can employ management strategies, such as fuel economy 

incentives, to encourage drivers to reduce idle time. 

Another promising strategy to reduce engine idling is truck stop 

electrification, where systems are installed at truck stops, rest areas, or 

terminals. Such systems provide heat and air conditioning as well as 

electrical shore power inside and outside stationary trucks, allowing 

drivers to turn off their truck engines while they rest or wait to load and 

unload. Pilot projects are underway in several areas of the country, 

including New York and southeast U.S. 

Implementation: Greater education on the economic and environmental 

impact of excessive idling and on idling reduction strategies and 

equipment could inform truck operators and help reduce emissions. As 

part of this effort, the Fleet Outreach and Awareness Program will work 

with industry experts to develop and distribute educational materials and 

conduct workshops on measures to reduce idling and the benefits that 

could be derived. The program could also work with a local truck stop to 

implement a pilot project to reduce vehicle idling, including truck stop 

electrification. 

111-3 
Accelerated Vehicle 

Retirement, Retrofit, 

and Alternative 

Fuel Projects 

Chapter Ill: On-Road Diesel Vehicles 

New diesel engine technology, control devices, and fuel changes 

continue to result in remarkable reductions in diesel emissions. 

Opportunities exist to introduce these technological advances into the 

marketplace sooner through voluntary programs that encourage: 

• accelerated retirement of pre-1990 trucks and buses and 

replacement with newer, cleaner engines; 

• retrofits with after-treatment (post-combustion) control devices, such 

as catalytic converters and particulate traps; 

• installation of low-NOx calibration devices in advance of engine 

rebuild as required by federal consent decree; 

• use ultra-low sulfur fuel in combination with after-treatment control 

devices; and 

• use of alternative fuels, such as compressed natural gas (CNG) and 

biodiesel. 

The U.S. Environmental Protection Agency (EPA) has developed the 

Voluntary Diesel Retrofit Program as an immediate solution to reducing 

emissions from existing diesel construction equipment and heavy-duty 

vehicles operating on the road today. EPA's goal is to reduce emissions 

from the existing fleet until new diesel standards take effect in 2007. 

According to the Diesel Technology Forum, the initial, narrow definition of 

retrofits has been expanded to include the "5 R's" of upgrading and 

modernizing diesel equipment- repowering , rebuilding, retirement, 

refueling, and retrofitting. 

The goal of the EPA's program was to secure, by the end of 2001 , 

commitments to retrofit 100,000 trucks, buses, and construction vehicles 

with commercially available emission control technologies. As of the end 

of 2001 , EPA calculated over 70,000 vehicles committed to retrofit 

equipment. See Appendix A for a summary of current voluntary retrofit 

projects around the nation. 

As part of the immediate effort to reduce diesel emissions, EPA 

developed a web site- www.epa.gov/otaq/retrofit- devoted to helping 

fleet operators, air quality planners in state/local government, and retrofit 

manufacturers understand the voluntary program and obtain the 

information needed to implement voluntary retrofit projects. 

In addition, the web site explains the economic incentives to the program 

and emissions credit trading . Also, the web site lists verified retrofit 

technologies, including retrofit manufacturers, type of technology, and the 

percentage of emissions reductions. 

111-4 
Chapter Ill: On-Road Diesel Vehicles 

For more information on EPA's Voluntary Diesel Retrofit Program, visit 

the EPA's OTAQ web site at www.epa.gov/otaqlretrofit. Also consult the 

Diesel Technology Forum's web site at www.dieselforum.org for more 

information. 

Implementation: As part of the outreach effort with fleet operators, the 

Fleet Outreach and Awareness Program will provide information on 

retrofit/retirement options for reducing emissions and maintain a data 

base of pilot projects around the country. Materials will provide 

information on the costs and benefits of these actions. 

The program will work with truck owners, vehicle manufacturers, and 

government agencies on public-private partnerships to fund such 

projects. Such incentives could come from grants, tax exemptions or 

rebates, manufacturers' rebates, and other sources. 

Diesel Fleet Survey A survey of diesel fleets operating in the Denver area, and possibly along 

the Front Range, is needed to determine the current composition of 

diesel vehicles in the area. The survey will be useful for the recognition 

program by identifying those fleets with innovative programs to reduce 

emissions. The survey will also be used to target fleets for particular 

outreach efforts. 

Implementation: The RAQC will work with the CMCA and its members to 

prepare and distribute the survey and compile the results. 

Clearinghouse of A number of programs exist at the state and federal level which provide 

Incentive Programs incentives for acquiring low emission vehicles or equipment related to 

and Emission retrofitting vehicles to reduce emissions. There are also a myriad of new 

Requirements and existing emission requirements for diesel vehicles. According to the 

industry, truck owners and operators have difficulty finding current and 

comprehensive information on incentive programs and regulatory 

requirements. 

Implementation: The Fleet Outreach and Awareness Program will 

serve as a central repository locally where companies and potential users 

may quickly find current and accurate information relating to emission 

requirements, new technology, and potential incentives at the state and 

federal level to reduce emissions. 

A web site will be developed to serve as a clearinghouse of information 

on the fleet program including: 

• dates, times, and locations of workshops and annual awards 

ceremony ; 

• recognition of exemplary fleets; 

111-5 
Cost and Funding 

Sources 

Chapter Ill : On-Road Diesel Vehicles 

• access to NEMPPA's Best Practices Manual; 

• information on vehicle idling reduction strategies; 

• access to database highlighting nationwide pilot projects using 

accelerated retirement, retrofit, ultra-low sulfur fuel , and alternative 

fuels; 

• access to a database containing information relating to emission 

requirements and potential incentives at the state and federal level to 

reduce emissions; 

• access to all promotional materials created from the fleet program; and 

• access to the final report put together at the end of the first year, 

including survey results. 

The RAQC staff estimates the first year of the Fleet Outreach and 

Awareness Program will cost approximately $125,000. This includes 

the staff time to develop materials, coordinate events and workshops, 

visit fleet operators, and document the results. It also includes costs to 

produce materials, establish the web site, prepare awards, sponsor 

workshops and recognition events, and promote the program. 

The RAQC will take the lead in seeking sources of funding for the 

program and preparing funding proposals and applications. Potential 

sources of funding include various EPA grant programs (including the 

Voluntary Diesel Retrofit Program, which has expressed significant 

interest in a retrofit project in the Denver area), private sector 

contributions, other public sector grant programs, and foundations. 

111 -6 
Chapter IV. Diesel Inspection and Maintenance 

Background 

In the mid-1980s concern for the Denver area's "Brown Cloud" led the 

state legislature to launch diesel emission control activities in the State of 

Colorado. Legislation passed in 1986 required all diesel vehicle owners 

in the AIR Program area to pay a $10 per vehicle registration to fund 

diesel vehicle emissions control activities of the CDPHE and Department 

of Revenue. The fee, which remains in effect today, is deposited into the 

AIR account of the highway users tax fund , subject to annual 

appropriation. The fee is used to fund the state's diesel inspection 

program as well as other related studies. 

In 1986, the Air Pollution Control Division Mobile Source Program studied 

the use of a loaded mode test on 13 excessively smoking light-duty diesel 

vehicles to determine the impacts of maintenance on opacity and 

emissions reduction. The Metropolitan Air Quality council, the lead local 

air quality planning agency at that time, recommended a diesel inspection 

and maintenance program in a lengthy report (January 1987) to "help 

significantly reduce "Brown Cloud"-causing particulate emissions from 

metro area diesel vehicles". In 1987 the EPA designated the Denver 

metro area as a "Group 1" PM-1 0 nonattainment area due to high levels 

of total suspended particulates in the air. In September 1987 a 

Governor's Blue Ribbon Panel was convened to address excess diesel 

smoke emissions from on-road vehicles. 

The Diesel Fleet Self Certification Program, a self-test program for fleets 

of nine or more heavy-duty vehicles, was established in 1987. The Diesel 

Opacity Inspection Program (DOIP) for all other diesel vehicles including 

light-duty cars and trucks and heavy-duty vehicles was established in 

1990 and included a $5 fee per tested vehicle to provide support of the 

diesel portion of the APCD's Mobile Source Program. Historically, diesel 

1/M programs have focused on smoke emissions not only because of 

their apparent direct link to air pollution but also because of nuisance and 

public perception issues. 

IV-1 
Chapter IV: Diesel Inspection and Maintenance 

The Colorado Diesel liM program was included in the initial PM-10 State 

Implementation Plan (SIP) adopted by the AQCC and approved by EPA. 

However, the AQCC removed the program from the PM-1 0 maintenance 

plan that was submitted to EPA in July 2001 . Upon final approval of the 

maintenance plan by EPA, the Diesel 1/M program will no longer be part 

of the federally-enforceable SIP and changes to the program will not 

require EPA review and approval. 

Current Colorado Programs 

Light-duty Diesel Vehicles- State statute (42-4-406, C.R.S.) and Colorado Air Quality 

Opacity Inspection Control Regulation 12 (Regulation No. 12) requires light-duty diesel 

Program (DOIP) vehicles registered or required to be registered or operating from a 

facility in the nine-county AIR Program area to be inspected annually at a 

state licensed decentralized light-duty diesel testing station under the 

DOIP. There are currently 31 state licensed (decentralized) inspection 

stations in nine-county Front Range AIR Program area. A two model year 

exemption is currently allowed. 

State statute and Colorado Regulation No. 12 defines a light-duty diesel 

vehicle as a vehicle weighing 7,500 pounds empty weight (curb weight) or 

less. Such vehicles could have a gross vehicle weight (GVWR) up to 

16,000 pounds. 

Test Procedure - The inspection includes a full-load lugdown test on a 

light-duty diesel dynamometer with an opacity meter used to measure 

visible smoke in the exhaust. The opacity cut point for naturally aspirated 

vehicles is 40% and turbo charged vehicles is 35%. Approximately 1-2% 

of the vehicles tested in calendar years (CY) 2000 and 2001 failed their 

first test. Mandatory repairs are required for failing vehicles. 

Costs - In CY 2000 approximately 18,000 vehicles were inspected/tested 

at an average of $44 per vehicle, which includes a $5/vehicle fee sent to 

the state. Also, $10 of the vehicle registration fee is sent to the state AIR 

account. The mean repair costs for a failed LDDV was reported to be 

$217. 

Heavy-duty Diesel Vehicles- State statute (42-4-406, C.R.S.) and Regulation No. 12 

Opacity Inspection requires heavy-duty diesel vehicles registered or required to be 

Program (DOIP) registered or operating from a facility in the AIR program area to be 

inspected annually at a state licensed decentralized heavy-duty diesel 

testing station under the DOIP. There are 31 state licensed 

(decentralized) inspection stations in the nine-county Front Range AIR 

Program area. A two model year exemption is allowed. 

IV-2 
Chapter IV: Diesel Inspection and Maintenance 

State statute and Colorado Regulation No. 12 defines a heavy-duty diesel 

vehicle as vehicle weighing greater than 7,500 pounds empty weight. 

Such vehicles probably will have a GVWR greater than 16,000 pounds. 

Test Procedure - The inspection includes a full-load lugdown test on a 

heavy-duty diesel dynamometer with an opacity meter used to measure 

visible smoke in th·e exhaust. The opacity cut point for naturally aspirated 

vehicles is 35% and turbo charged vehicles is 20%. Approximately 1-2% 

of the vehicles tested in CYs 2000 and 2001 failed their test. Mandatory 

repairs are required for failing vehicles. 

Costs- In CY 2000 approximately 13,000 vehicles were inspected/tested 

at an average of $65 per vehicle, which includes a $5/vehicle fee sent to 

the state. Also, $10 of the vehicle registration fee is sent to the state AIR 

account. The mean repair costs for a failed HDDV was reported to be 

$571. 

The RAQC staff estimated indirect cost to an owner at $50 per vehicle to 

take the vehicle in for inspection and return to home base, assuming a 

total of 2 hours at $25 per hour for a shagger/driver. 

Heavy-duty Diesel Vehicles- State statute (42-4-414, C.R.S.) and Regulation No. 12 

Fleet Self- requires heavy-duty diesel vehicles in fleets of nine heavy-duty vehicles 

Certification Program or greater, registered or required to be registered in the AIR program 

(DFSCP) area, to be inspected annually. Fleets are allowed to provide an annual 

self-inspection prior to registration under the Diesel Fleet SelfCertification Program. A two model year exemption is allowed. 

Test Procedure- A full load test is required, but lugdown, stall or 

acceleration options are allowed, and the test can be done on-road or 

with a dynamometer. Opacity meter measurement or visual assessment 

of smoke is allowed during the testing . The opacity cut point for naturally 

aspirated vehicles is 35% and turbo charged vehicles is 20%. 

Approximately 0.5% of the vehicles tested in CYs 2000 and 2001 failed 

their first test. Mandatory repairs are required for failing vehicles. 

Costs - Fleets in the self-certification program do not pay a vehicle 

inspection fee to the state. However, $10 of the vehicle registration fee is 

sent to the state AIR account. There are approximately 22,000 fleet 

vehicles in the AIR Program area. 

In CY 2000 approximately 14,580 vehicles were self inspected/tested. 

The RAQC staff estimated indirect cost to an owner at $25-30 per vehicle 

for an inspection, assuming a total of 45 minutes per inspection at a $35 

per hour 

rate for an inspector-technician. The mean repair costs for a failed HDDV 

IV-3 
Chapter IV: Diesel Inspection and Maintenance 

was reported to be $927. No estimate has been made of indirect costs for 

training of inspection officer, test equipment or out of service vehicles. 

Additional Program The continued use of visual observers in the self-certification fleet 

Observations program is considered questionable. 

The continued use of opacity as a surrogate measurement tool to identify 

high- emitting vehicles is questionable in light of the poor correlation 

between opacity and PM emissions. At best opacity levels identify some 

but not all high-emitting engines. 

The data reporting and analysis system is considered to be inadequate 

because the in-use optical mark reader/fill-in-the-bubble paper forms are 

time consuming, limited, and subject to inaccuracy and error. The 

computer system where the data is stored and analyzed is obsolete, 

cannot be updated, and cannot communicate with other interrelated 

databases (e.g. the self cert fleet audit database etc.). 

Migration and registration outside AIR Program area is an issue because 

a diesel vehicle normally housed and serviced outside the AIR Program 

area, but normally operated within the AIR Program area is not currently 

required by statute to be inspected. The interpretation of "required to be 

registered or operating from a facility in the AIR Program area" by the 

APCD is that a vehicle normally housed and serviced in the AIR Program 

area should either be registered in the program area (and therefore 

inspected annually) or be inspected annually regardless of location of 

registration. 

Data from a 1998-99 DR COG study at the borders of the metro area 

indicate approximately 7,000 large diesel vehicles (greater than 7,500 lbs. 

GVWR) registered in Colorado, displaying no inspection sticker and 

starting and ending the day at the owner's lot/terminal enter/leave the 

metro area on a daily basis. Using the reported 13,000 DOIP inspected 

vehicles, the 22,000 DFSCP vehicles and the up to 7,000 vehicles noted 

above, it can be estimated that approximately 17% (7,000/42,000) of the 

Colorado HDDV vehicles operated in the metro area on a week day basis 

are not currently annually inspected. This does not include out-of-state 

vehicles. 

Diesel 1/M Testing Procedures 

Colorado Lugdown The Colorado 1/M programs utilize a full load test, which measures 

stabilized full power operation, similar to "pulling a grade" with a load . 

Vehicles are tested at full power load applied on a dynamometer; or using 

vehicle brakes or transmission. Colorado uses a full power-load applied 

test on a 

IV-4 
Chapter IV: Diesel Inspection and Maintenance 

dynamometer for the DOIP. The DFSCP utilizes a full power-load applied 

test but allows an option of using a dynamometer, vehicle brakes or 

transmission. 

The current federal opacity certification level for a lug test is 15%, which 

was established in 197 4. Most vehicles today are tested at certification 

well below 10% opacity. The lugdown test on a dynamometer is 

considered a better test for diagnosis of problems in failing vehicles. It is 

also a time-consuming and costly test compared to a J1667 snap 

acceleration test. The current Colorado opacity cut points (20% for turbo 

charged vehicles) do not fail approximately 10%-15% of the heavy-duty 

fleet that would fail the current J1667 test procedure. 

Currently, two other states, Arizona and Utah, with mature diesel 1/M 

programs, utilize a full-load test. At such time that shop grade PM 

measurement equipment is available (some estimate two years hence), a 

loaded test on a dynamometer will most probably return to favor. 

Although California's roadside pullover program currently uses the J 1667 

snap test, California is actively testing a roadside dynamometer. 

SAE J1667 The SAE J1667 procedure is a no load test, where the engine throttle is 

"snapped" wide open from idle speed to governed revolutions per minute 

(RPM) in a series of three clean out snaps and a series of three snap 

tests averaged together. The test measures transient acceleration 

smoke opacity. The EPA recommended opacity cut points are 55% for 

MY 1991 and older and 40% for MY 1992 and newer. 

Comparison: 

Colorado Lugdown 

and SAE J1667 

The test is inexpensive requiring only an opacity meter. The test is 

completed very quickly, taking approximately 5 to 10 minutes. EPA is 

currently recommending the SAE J 1667 test procedure to states 

considering heavy-duty diesel 1/M programs, until such time that shop 

grade PM emissions testing technology is available. At that time, EPA 

will review its position on the J1667 test and opacity testing in general. 

California uses the J 1667 test procedure for both their Roadside Program 

and Fleet (Periodic Smoke Inspection) Program. 

A study in Colorado Springs, CO in 1997 applied the J1667 test with EPA 

recommended cut points to a group of approximately 120 HDDV that had 

just completed the Colorado lugdown test at the current program cut 

points in the DOIP. It was found that the approximately 17% of the 

vehicles failed the J 1667 test while only 1. 7% of the same vehicles failed 

the Colorado lugdown test. Rather than suggesting that one test is better 

than the other this study suggests that the cut points are not set 

appropriately for an equivalent test. 

IV-5 
Chapter IV: Diesel Inspection and Maintenance 

A study in New York by EEA in 2000 using 37 HDDV, J1667 testing, and 

the Radian malperformance model demonstrated that lugdown testing 

and repair with appropriate opacity cut points (15% for pre-1991 vehicles 

and 10% for post-1991 vehicles) would result in equivalent PM reduction 

found in a J1667 testing and repair program with EPA-recommended cut 

points. 

Programs in Other States 

California Programs California operates two vehicle inspection programs that are distinct in 

that they are codified in different parts of state statute. They were also 

adopted in different years. However, the Roadside Program is a stand 

alone program adopted in 1988, while the Periodic Program adopted in 

1990 derives its enforcement authority from the legislation that 

established the Roadside Program. 

California Heavy-Duty Vehicle Inspection Program (HDVIP) 

Vehicles & Test- All (570,600 estimated) HDDV traveling California's 

roads - interstate, intrastate, international - are subject to roadside 

enforcement based on visual observation followed by an immediate SAE 

J1667 (snap-accel.) test.The opacity cut point for the J1667 test for pre 

1991 HDDV is 55%; while for 1991+ HDDV it is 40%. 

Penalties- Pre-1991 HDDV with opacity measurements between 55 and 

70% are given a Notice of Violation ("fix it ticket") requiring repair within 

45 days without penalty; failure to repair vehicle results in a citation 

($300) plus added penalty of $500. Citations are issued to all others 

vehicles (pre-1991 vehicles above 70% and all post-1991 failing the cut 

points). The penalties are $300 to $1800 and possible vehicle 

impoundment depending on number of citations issued before 

compliance. 

Fail Rate- In California's testing program 64,648 visual Inspections were 

performed between June 1998-September 2001 . During this time frame 

1,154 notice of violation (NOVs) and 3,384 citations were issued. This 

established a fail rate of 7% of visually inspected vehicles. Program 

managers indicate that they currently test approximately 20,000 vehicles 

annually and continue to expect a 7% fail rate, which equates to 

approximately 1 ,400 vehicles failed annually. 

Cost- Estimates of cost of repairs and fuel saved are approximately 

equal. The total program costs are estimated at $5.6 million annually 

based on vehicle owners cost estimated at $1 .9 million for increased 

maintenance 

IV-6 
Chapter IV: Diesel Inspection and Maintenance 

and lost opportunity cost of time and the State cost of $3.7 million 

annually 

to inspect the vehicles. Highway Patrol cost in support of the inspection 

program is not included. The annual program cost is estimated at $280 

per vehicle inspected. 

California Periodic Smoke Inspection Program (PSIP) 

Vehicles & Test- All fleets of 2 or more California-registered HDDV, 

approximately 291 ,600 HDDV, are subject to an annual self-inspection 

which includes the SAE J 1667 (snap-acceleration) test. A 4 model year 

exemption is allowed, which is estimated at 26% of the fleet vehicles.The 

opacity cut point for pre-1991 HDDV is 55% and for 1991+ HDDV the cut 

point is 40%. 

Compliance Audit- The California Air Resources Board (CARB) audits 

fleets for compliance- less than 1% of the fleets require formal action. 

State cost for auditing the fleets is approximately $0.5 million annually. 

Fail Rate - A 7% failure rate of the inspected vehicles is estimated by 

program managers. 

Cost- Estimates of cost of repairs and fuel saved are approximately 

equal. The cost of self testing is borne solely by the vehicles owners and 

is estimated at $18.1 million annually based on costs for labor, test 

equipment, contract testing and increased maintenance costs. The 

annual program cost is estimated at $84 per vehicle inspected. 

Summary of Currently 17 states and two Canadian provinces have some of type of 

Programs in Other diesel 1/M program. Many have a road side testing element while several 

States and Provinces have fleet self-certification programs. The following table, excerpted from 

a report prepared by Environment Canada, summarizes the various 

programs in North America. 

IV-7 
Chapter IV: Diesel Inspection and Maintenance 

SAE J1667 Test Procedure Lug-Down Test 

States & Provinces Fleet Self Traditional Fleet Self Traditional 

Road Side Cert. 1/M Cert. 1/M 

Arizona X 

British Columbia X 

California X X 

Colorado X X 

Connecticut X 

Illinois X X 

Indiana (vol.) X 

Maine X 

Maryland X 

Massachusetts X X 

Nevada X 

New York City X X 

New York (outside NYC) X 

NewHampshire X 

New Jersey X 

Ontario X X 

Rhode Island X X 

Utah (Davis Co.) X 

Utah (Utah Co.) X 

Vermont X 

Washington X X 

Recommendations 

Since Colorado's diesel inspection/maintenance (1/M) program was first 

established nearly 15 years ago, diesel vehicle technology has changed 

dramatically and emissions from light-duty diesel vehicles and heavy-duty 

trucks and buses have been reduced significantly. These technological 

changes are not reflected in the current program . 

Taking into account the advances that have occurred in the last 15 years, 

the Diesel Stakeholder Work Group clearly recognized the current 

program is not as efficient or as effective as it could be. There are no 

quantitative data available to judge how effective the current program is 

reducing diesel emissions. However, many program observers believe 

the program provides undeniable benefits as an incentive for good 

maintenance and as a deterrent to vehicle tampering. 

Through in-depth discussions over a period covering six meetings, the 

Work Group considered changes to make the program both more 

efficient and more effective. The recommendations outlined below are 

intended to reduce the burden of the program on vehicle owners, 

particularly those who have invested in new engine and vehicle 

technology. Other recommendations will help ensure the program 

identifies high-emitting vehicles that require repair and maintenance to 

reduce diesel emissions. 

IV-8 
Chapter IV: Diesel Inspection and Maintenance 

It is important to remember that a diesel inspection/maintenance program 

is a particulate matter (PM) reduction strategy. The program identifies 

vehicles with high levels of smoke that indicate excessive particulate 

emissions. An 1/M program cannot be viewed as a NOx reduction 

strategy since poorly performing diesel vehicles generally lower NOx 

emissions and repairs and maintenance to make the engine operate 

properly increase NOx emissions. Studies have shown, however, that 

NOx emissions after repairs are still within certified limits for the vehicles. 

Necessary NOx emission reductions therefore need to be addressed 

through other types of diesel strategies, such as engine replacement and 

retrofits, idling strategies, and fuel strategies. 

Maintain the basic The Work Group concluded current structure of Colorado's diesel 

structure of the inspection/maintenance program is well-established and accepted by 

current program diesel vehicle owners. However, there are changes that can be made 

within the current structure that will make the current program more 

efficient and effective. 

The discussion below presents the recommendations from the Work 

Group, explains the rationale, and indicates the implementation steps that 

are need to accomplish the recommendation. Following the discussion 

are tables that summarize the net effect of the recommendations and 

summarize what will need to be addressed through statutory changes 

and what can be handled with current regulatory and administrative 

authority. 

Recommendation #1 Review the Diesel Inspection/Maintenance program within the next 

two years to determine if further improvements are necessary and 

feasible. Develop a research protocol and necessary funding to 

conduct periodic evaluations of program effectiveness. Identify 

further specific information and data needs and questions that need 

to be answered. 

A strong feeling by the Work Group was expressed concerning the lack of 

a diesel 1/M program review in the past 15 years since the start of the 

program. It is obvious that the current program has not kept pace with 

changing standards and diesel technology since shortly after program 

inception. A review in the next two years seemed appropriate to review 

what has been accomplished and what is needed in the future in light of 

more stringent standards taking effect in 2004 and 2007. 

Once the direction of the diesel emissions program is reestablished , a 

means to track progress toward that goal should be included in the 

program redesign. This applies regardless of what type of program -

IV-9 
Chapter IV: Diesel Inspection and Maintenance 

periodic inspection, roadside enforcement etc; or the goal of the program 

-PM, opacity, citizen complaints, etc. A pre-changeover baseline 

measure should be taken , with periodic evaluation by the same measure 

to ensure progress is being made. Measurement tools need to be in 

place before the changeover. This would provide a tool for assessing 

program effectiveness. 

The discussion of program needs has been open ended. Often the data 

are available, but are not easily accessible or need to be looked at in a 

different way. Specific information and data need to be obtained that can 

provide answers to questions and issues that have not been addressed. 

Implementation- Currently there is no requirement or process for a 

systematic, regular review of the Diesel 1/M program. Existing statute 

requires the AQCC to review the Diesel 1/M program fail rates annually, 

but this has not been an in-depth review that would provide a critical 

analysis of the performance and effectiveness of the program. 

Within the next two years, the RAQC and AQCC should undertake 

another stakeholder process to perform as additional review of the 

program, assess implementation of current recommendations , and 

determine future program needs. In the meantime, technical staff with 

the CDPHE Mobile Sources Program, with assistance from the RAQC, 

should initiate studies or data analyses to answer some questions 

remaining after the current stakeholder process. 

Funding from the General Assembly will be needed to conduct a more 

rigorous periodic evaluation of program effectiveness. CDPHE should 

determine the cost of such an effort and seek an appropriation from the 

legislature during the next legislative session. 

Recommendation #2 Automate data reporting and analysis and develop an internet-based 

system for information exchange. 

The in-use optical mark reader/fill-in-the-bubble paper forms are time 

consuming, limited, and subject to inaccuracy and error. The computer 

system where the data is stored and analyzed is limited in its capabilities, 

obsolete, cannot be updated, and cannot communicate with other 

interrelated databases (e.g. the self-cert fleet audit database etc.). 

Data collection , storage, analysis, and reporting need to be redesigned 

from front to back as an integrated system, fully accessible to program 

staff. 

On-line data collection may be an attractive option- Inspector enters 

inspection data directly into a keyboard , eliminating handling of paper 

forms. 

IV-10 
Chapter IV: Diesel Inspection and Maintenance 

No current cost estimate has been developed for an up-to-date system. 

Implementation- The APCD Mobile Source Program will have to 

analyze program data and management needs, reporting needs for fleet 

and non-fleet vehicle inspectors and develop cost estimates for an up-todate and expandable data management and analysis system that will be 

useful into the future. The CDPHE will have to seek legislative 

appropriation of funds from the AIR account to implement such a system. 

Recommendation #3 Add an on-road enforcement element to the program, either through 

remote sensing, smoking vehicle hotlines, or limited roadside 

pullovers (based on probable cause). 

In California and other states, on-road enforcement has proven to be an 

effective supplement to the state's fleet inspection program. The threat 

of on-road enforcement has encouraged proper maintenance on diesel 

vehicles and improved compliance with the periodic inspection program. 

On-road enforcement will also identify vehicles with excessive smoke and 

emissions that have either fallen into disrepair or somehow escaped 

periodic inspections. 

California's on-road enforcement program involves roadside pullovers of 

heavy-duty diesel vehicles with excessive smoke. State police and 

trained inspectors identify vehicles on the road and conduct an on-thespot roadside SAE J1667 test. Vehicles thaffail the test are issued a 

citation and required to bring the vehicle into compliance with necessary 

repairs. California's program costs $5.6 million per year and identifies 

1,400 vehicles per year. 

An on-road pull over program in Colorado would most likely use the SAE 

J 1667 test procedure. A confirmatory test would be required at a state 

licensed inspection station, which uses the Colorado lug down test 

procedure. To provide a consistent evaluation of the vehicle, the current 

difference in fail rates due current cut points of the two tests, discussed 

previously in this report, will have to be addressed. 

Other methods for on-road vehicle identification exist, including smoking 

vehicle hotlines, identification by trained personnel, and remote sensing. 

Smoking vehicle hotlines use citizen complaints to identify problem 

vehicles, but owner compliance tends to be voluntary. The City and 

County of Denver operates an effective smoking vehicle program 

whereby trained city staff identify smoking vehicles on the road . Vehicle 

owners are issued a citation where they are required to fix vehicle or face 

legal action. 

IV-11 
Chapter IV: Diesel Inspection and Maintenance 

Remote sensing technology (RSD) is under development to identify both 

heavy-duty and light-duty diesel vehicles. An improved version of RSD 

that can take accurate opacity readings for light-duty vehicles is close to 

commercial application. However, remote sensing for heavy-duty 

vehicles is more challenging since their exhaust points vary and are more 

difficult to measure. 

It is envisioned by the Work Group that any on-road enforcement 

program will start out on a small scale and be phased in gradually over 

time. This will provide the opportunity to implement the program 

efficiently by working through the pitfalls of such a new approach. 

Implementation- Statutory authority (42-4-413, C.R.S.) for on-road 

identification and enforcement currently exists, but it proved insufficient to 

withstand initial challenges in court by owners of vehicles involved in an 

enforcement action in the late 1980's. Since that time law enforcement 

officers have not given on road enforcement a high priority. Therefore 

new legislation likely will be necessary to strengthen statutory authority to 

identify vehicles on the road and provide an effective mechanism for 

enforcement. 

Recommendation #4 Define heavy-duty diesel vehicles as those greater than 14,000 

pounds gross vehicle weight (GVWR) and eliminate the reference to 

empty weight or curb weight in Regulation No. 12. 

The current definition of light-duty vs. heavy-duty vehicles is based on the 

7,500 pounds empty weight (curb weight) limit, which means the weight 

of the vehicle at the curb filled with all of its required fluids. Such lightweight vehicles can then be outfitted to do specific work and may in fact 

have a GVWR up to 16,000 pounds. This recommendation seeks to 

separate the transportation vehicles (driven to a job site or office and left 

to the end of the day, or pulling a boat on the weekend) from the working 

vehicles (outfitted as a tow truck, for instance). 

Implementation - Since the current definition of light and heavy-duty 

vehicles is currently in state statute a statutory change will be required . 

Since the current Air Quality Regulation also defines and describes the 

testing of light and heavy-duty vehicles, a regulatory change will also be 

required . 

IV-12 
Chapter IV: Diesel Inspection and Maintenance 

Recommendation #5 Increase model year exemptions to four years for heavy-duty diesel 

vehicles and decrease test frequency to biennial testing for HDDV 10 

model years and newer (beginning with MY 1995) under both 

programs. 

The technology for light-duty diesel vehicles has also improved and new 

Tier 2 standards affecting light-duty vehicles will take effect within two 

years. However, the Work Group does not recommend increasing the 

model year exemptions for these vehicles beyond the current two-year 

exemption. 

Anecdotal information provided from actual observations by emissiontesting representatives indicates light-duty diesel vehicles used for 

personal use may not be as well-maintained continuously like commercial 

vehicles. Unlike gasoline vehicles, diesel vehicles may experience 

emission problems while performing acceptably to the owner. In addition, 

after-market add-on equipment is more prevalent with light-duty vehicles 

and may change the emission performance of these vehicles. Without 

annual inspections, these vehicles may be emitting high levels of pollution 

without the owner realiz)ng the condition. Maintaining a two-year model 

year exemption and an annual inspection cycle for light-duty vehicles will 

ensure these vehicles continue to operate at their designed low emission 

levels. 

The net effect of the increased model year exemptions and biennial 

testing for newer vehicles is that heavy-duty diesel vehicles will be tested 

three times during their first 10 years, compared to eight times under the 

current program. This will save vehicle owners at least $300 per vehicle 

in testing costs over this time period. 

Current statute also requires heavy- and light-duty diesel vehicles to pass 

an emissions test before they can be registered upon change of 

ownership. The same requirement applies for the gasoline vehicle 

emissions testing program. The Work Group does not recommend 

changing this requirement in current statute. Requiring an emissions test 

upon change of ownership is a consumer protection issue and protects 

vehicle purchasers from hidden emission problems. The General 

Assembly has considered this on several occasions for the gasoline 

program and has resisted attempts to alter the requirement. 

Implementation- Since current statute specifies a two-year exemption 

and an annual testing requirement after the initial exemption, legislation 

will be necessary to increase the model years exemptions and 

decreasing the testing frequency for newer heavy-duty vehicles. 

Legislation can be introduced as early as the 2003 session of the General 

Assembly. 

IV-13 
Chapter IV: Diesel Inspection and Maintenance 

Recommendation #6 Modify state statute to require testing of all diesel vehicles routinely 

operated in the program area, not just those registered, required to 

be registered or housed in the program area as currently required. 

Current statute (42-4-406, C.R.S.) requires emissions testing for all diesel 

vehicles that are registered, required to be registered or are principally 

operated from a terminal , maintenance facility , branch or division located 

within the program area. Still, it is believed that many vehicles that 

routinely and continuously operate in the program area avoid the testing 

requirement either by ignoring (intentionally or unintentionally) the law or 

by registering and/or housing the vehicles outside the program area . 

The Work Group recommends closing the loophole by requiring all 

vehicles that routinely operate in the program area be subject to emission 

testing requirements , as similarly required of vehicles in the gas program, 

regardless of where they are registered or housed. There will also be a 

need for greater education on and enforcement of this and the current 

requirement so that vehicle owners comply with the law. Currently there 

is no requirement for a windshield inspection sticker, but proof of 

emissions inspection is required to be carried in the vehicle. An on-road 

enforcement program will also help identify problem vehicles that are 

avoiding the requirement. 

Implementation- Legislation will be necessary to modify current statute 

(42-4-406 & 414, C.R.S.) to require testing for vehicles that routinely and 

continuously operate in the program area, regardless of where they are 

registered or housed. The APCD will also need to increase its education 

and compliance efforts so vehicle owners do not avoid the requirement. 

Recommendation #7 Maintain current testing protocols with the following changes: 

- allow SAE J1667 (or other future automated testing 

protocol) as an option for all HDDV 10 model years and 

newer in the fleet program; 

- require lugdown test for all HDDV older than 10 model 

years in both programs; and 

- eliminate visual testing, during a two-year phase in period, 

as an option for all HDDV in the fleet program older than 10 

model years. 

The lugdown emissions test is currently required for both the fleet and 

DOIP programs. The test is generally performed on a dynamometer and 

is considered an effective test for measuring opacity from diesel vehicles. 

IV-14 
Chapter IV: Diesel Inspection and Maintenance 

SAE J1667 is a relatively new test that is being used in many states, 

including California. The test is an automated acceleration test that is 

generally easier and less costly to perform. However, it measures a 

different operating condition than the current lugdown test. 

The Work Group recommends allowing fleet operators the option to use 

the J 1667 test, or some other approved automated testing procedure, on 

heavy-duty vehicles that are 10 years old and newer. The fleet operator 

would have to choose J1667 or lugdown for a// its newer vehicles and 

would not be able to pick and choose. Again, since these newer vehicles 

are inherently cleaner, J 1667 should be able to identify emission-related 

problems in these vehicles, especially during acceleration. The lugdown 

test, which "exercises" the engine more, is still recommended and 

considered best for older vehicles. The lugdown test would also still be 

required for all vehicles in the DOIP. 

The Work Group also recommends eliminating visual observation as an 

option for the lug down test for fleet vehicles older than 10 years. Current 

regulation allows fleet operators to measure opacity either though visual 

observations or with an opacity meter. The use of an opacity meter is 

required in the DOIP and most fleet operators as well already use an 

opacity meter, which is more accurate and reliable than visual 

observation. The mandatory use of opacity meters would be phased in 

over a two-year period. 

Visual observations would still be allowed in the fleet program for newer 

vehicles, which should be smokeless and for which visual observation 

should be satisfactory. 

Implementation- Current statutory language concerning testing 

methods is fairly specific and does not allow J1667. Legislation will be 

necessary to allow J 1667 and other automated testing protocols. The 

testing provisions should be less specific so the Air Quality Control 

Commission (AQCC) has authority to modify testing protocols and 

requirements as new protocols are developed and become more 

appropriate. 

Eliminating visual observations for tests of older vehicles does not appear 

to be constrained by current statute, so the AQCC can make necessary 

revisions to Regulation No. 12 to address this issue. However, the AQCC 

may want direct legislative authority to change this requirement. 

IV-15 
Chapter IV: Diesel Inspection and Maintenance 

Recommendation #8 Since opacity is not a good measure of emissions for newer 

technology vehicles, Colorado should work in a joint effort with EPA 

and other states to conduct research and pilot studies to develop 

appropriate emissions-based testing methods for future 

consideration. 

Opacity testing is currently the measurement of choice for all diesel 1/M 

programs. Measurement is based on a light extinction opacity meter or 

visual observation by a trained smoke inspector. Although high opacity 

readings will indicate high PM emissions; low opacity does not 

necessarily indicate low PM . 

The current diesel engines are clean, virtually smokeless at certification 

and durable through their expected life. This has been accomplished 

through changes in engine design. However, lugdown testing still finds 

some newer engines that have excessive smoke above the 20% opacity 

standard. Engines designed for 2006 and beyond will include 

environmental control equipment such as catalyzed traps, selective 

catalatic reaction (SCR) systems, oxidation catalysts, and NOx absorbers 

that potentially will fail without increasing smoke. Emissions based 

testing will be needed at that time to identify vehicles not operating at 

near certification levels. 

CO and/or CO + HC emissions measurement under peak operating 

conditions may be a better surrogate for PM emissions than opacity. 

Shop grade measurement equipment is currently available. Direct PM 

emissions measurement technology is still under development; possibly 

available within a year or two. 

No estimate of required funding has been made. 

Implementation- Because the current statutes reflect an opacity-based 

program for the Diesel 1/M programs, a statutory change may be required 

or desired to fully investigate this issue. In the interim the RAQC/APCD 

should participate in national diesel conferences , EPA work groups and 

committees, and activities in California diesel 1/M development to monitor 

the direction of criteria pollutant diesel emissions based 1/M programs. 

Identified required research will require funding . 

Recommendation #9 Improve audit program by focusing on HDDV fleets with higher than 

normal out-of-service ratings or fail rates. 

The APCD staff currently visit every DFSCP terminal or yard at least once 

per year to audit the testing programs. However, failure rates overall of 

the DFCSP vehicles are in the range of 0.5 %, while the DOIP vehicles 

have a 2% fail rate. 

IV-16 
Chapter IV: Diesel Inspection and Maintenance 

It has been suggested that more effort should be focused on those fleets 

(large and small) that have a poor safety record. There is a strong feeling 

that vehicles that are not meeting safety standards are more than likely 

those that are also not meeting current opacity standards. Additionally, an 

emphasis should be made to address the fleets that have high fail rates 

regardless of size. 

It has been suggested that the Federal Motor Carriers Safety 

Administration Motor Carrier Safety Profiles Out Of Service (OOS) rating , 

which is internet accessible, be used to help focus audit efforts. 

The current staffing level can now barely meet the current regulatory 

requirement for the DFSCP audit. 

Implementation -This recommendation may be handled 

administratively by the Mobile Sources Program by directing and focusing 

resources on problem fleets . If additional resources are necessary, an 

additional appropriation from the General Assembly will be necessary. 

Recommendation Expand repair technician training and technical assistance similar to 

#10 the efforts for the gasoline vehicle program. 

The APCD Mobile Source Program currently does not have a Diesel 

repair training program, although a "tech night" for the diesel repair 

industry has been held recently wherein diesel repair issues were 

addressed by APCD staff and repair experts. Original Equipment 

Manufacturers (OEMs) also provide diesel technician training programs, 

but these are generally only available to those working for larger fleets. 

A diesel repair training program should be similar to the existing APCD 

Mobile Sources (MS) gasoline 1/M repair industry outreach/training 

system and should include: 

Emissions Technical Centers acting as a clearinghouse for 

specific diesel repair/diagnostic information; 

repair information to be made available to involved parties via 

print, phone, Tech Night', training classes, web site etc. This 

repair information is not intended for the general public -

liability; and 

basic electronic/electrical training . 

Requires resource commitment by CDPHE as well as a commitment by 

fleets, repair shops, manufacturers, and inspection stations to share 

repair/diagnostic information. The effectiveness of this project depends 

on the level of industry participation. 

IV-17 
Chapter IV: Diesel Inspection and Maintenance 

Implementation -This recommendation may be handled 

administratively by the Mobile Sources Program by directing and focusing 

resources on training and technical assistance. If additional resources 

are necessary, an additional appropriation from the General Assembly 

will be necessary. 

Recommendation Investigate using remote sensing technology to clean screen light-

#11 duty diesel vehicles or identify high-emitting vehicles. 

Advances in remote sensing technology may soon allow more accurate 

opacity measurements for light-duty vehicles. Therefore, the technology 

may exist to screen out clean (low-opacity), light-duty diesel vehicles and 

exempt them from routine emission tests. This could operate similar to 

the approach envisioned for the gasoline inspection program. High 

emitting vehicles could also be identified by the same technology. 

Implementation of such an approach would exempt clean vehicles that do 

not need be tested and would focus efforts on vehicles that are more 

likely to have emission problems. It would significantly decrease the 

burden of testing on diesel vehicle owners. 

Implementation- Given the current state of remote sensing technology, 

APCD and RAQC should investigate the feasibility of implementing a 

clean screen and/or high emitter program for diesel vehicles and 

integrating it with the gasoline vehicle remote sensing clean screen 

program. If a clean screen or high emitter program is determined to be 

feasible, legislation will be necessary to authorize implementation of such 

a program and provide for the mechanism administer the program 

consistent with the gasoline program. 

Recommendation Eliminate or increase the current repair cost waiver for failed diesel 

#12 vehicles. 

The highest number of waivers requested per year in the past two years 

has been four. Keeping the waiver limit is unnecessary. If the waiver limit 

is retained it should be raised to an appropriate level and adjusted to an 

index annually. 

There is a strong feeling that failing vehicles need to be repaired . Repair 

data indicates that partial repairs do not fix the problem. 

Implementation- A statutory change is required to eliminate the concept 

of a waiver rate. A regulatory change is required to increase the waiver 

rate. 

IV-18 
Chapter IV: Diesel Inspection and Maintenance 

Summary of Diesel 1/M Recommendations 

The following list summarizes the Work Group's recommendations by 

indicating those that will make the current program more efficient, those 

that will make the current program more effective, and those that keep 

current program elements the same. 

Recommendations -

making the program -

more efficient 

Recommendations -

maintaining 

current elements -

Recommendations -

making the program 

more effective -

Define HDDV as those >14,000 pounds GVWR 

Increase model year (MY) exemption for HDDV to 4 years (both 

programs) 

Decrease test frequency to biennially for HDDV 1 0-MY and newer 

(both programs) 

Allow choice of J1667 or lugdown test for HDDV 10-MY and newer in 

fleet program 

Automate data reporting and analysis 

Investigate using RSD technology to clean-screen LDDV 

Expand repair technician training 

Conduct periodic evaluations of program effectiveness 

Maintain basic structure of Diesel Opacity Inspection Program (DOIP) 

and Diesel Fleet Self-Certification Program (DFSCP) 

Maintain 2 model year (MY) exemption for LDDV 

Maintain annual testing for all LDDV 

Maintain annual testing for HDDV older than 10 MY (both programs) 

Maintain change of ownership testing requirement for all LDDV and 

HDDV 

Maintain visual observation testing option for HDDV 10 MY and 

newer in the fleet program 

Maintain lug down tests for HDDV older than 10 MY in the fleet 

program and for all HDDV in DOIP 

Require all vehicles operating (not just registered or housed) in the 

program area to participate in the program 

Add an on-road enforcement element to the program 

Eliminate visual testing , over two-year period, for fleet HDDV older 

than 10 MY in the fleet program 

Investigate emissions-based testing methods for future consideration 

Improve audits of fleet programs 

Expand repair technician training 

Eliminate or increase the current repair ost waiver for failed vehicles 

Conduct periodic evaluations of program effectiveness 

IV-19 
DFSCP HDDV . 

. 14,001 & . greater GVWR . 

. DOIP HDDV . 14,001 & . greater GVWR 

. 

. DOIP LDDV . 

. 14,000 & less . GVWR 

Chapter IV: Diesel Inspection and Maintenance 

Comparison of Recommendations Affecting 

Newer and Older Vehicles 

(10 Model Year Break Point) 

Newer Vehicles Older Vehicles 

(1 0 MY and newer) (> 10 MY) 

Allow visual test . No visual test allowed after a 

Allow either J1667 or the two-year phase in period ; 

current lug-down test opacity meter required 

Biennial testing for 10 MY . Require the current lug-down 

and newer (beginning test 

wl1995 MY) . Annual testing 

4 MY exemption 

No visual test allowed; opacity . No visual test allowed; opacity 

meter required meter required 

Requ ire the current lug-down . Requ ire the current lug-down 

test test 

Biennial testing for 10 MY . Annual testing 

and newer (beginning 

wl1995 MY) 

4 MY exemption 

Require current lug-down test . Require current lug-down test 

Annual test . Annual test 

2 MY exemption 

Note: Changes to current progra m are 1n bold. 

Opacity Cutpoints 

The Work Group spent considerable time discussing the opacity cutpoints 

for the current program and whether lowering cutpoints was feasible or 

advisable at this time. The Work Group could not come to consensus on 

this issues and therefore could not make any specific recommendations. 

However, the members agreed cutpoints are an issue and presented the 

arguments on both sides. 

Arguments for -

considering lower 

cutpoints 

The current opacity cutpoints for the various types and classes of 

diesel vehicles has remained unchanged since the program began in 

the late 1980's. 

Diesel engine technology has improved dramatically since that time, 

so current cutpoints for newer vehicles are no longer valid . 

The current low failure rate in the program, particularly for new 

vehicles, indicates that current cutpoints are not appropriate. 

A 20% opacity standard for newer turbo-charged LDDV would be 

justified since none of these vehicles fail the current 35% standard 

(which correlates to black smoke) and only 7% would fail a 20% 

standard. 

IV-20 
Arguments against -

considering lower 

cutpoints -

Chapter IV: Diesel Inspection and Maintenance 

Very few turbo-charged HDDV fail the current 20% standard and all 

are certified at levels well below that level. Only 3-5% for 1992 and 

newer HDDV would fail a 15% opacity limit. 

Lower cutpoints for naturally-aspirated vehicles are probably not 

justified because of the technology and the declining number of 

vehicles in the fleet. Between 30-40% of the current naturallyaspirated light- and heavy-duty fleet would fail a 20% standard. 

Data are not available to quantify the PM emissions reduction that 

would result from lower cutpoints. 

Merely lowering cutpoints does not necessarily make the program 

more effective. 

Because diesel emission data are skewed , lowering cutpoints may 

not result in a correlating reduction in emissions and there will be 

diminishing returns with lower cutpoints as a result. 

Since the Denver region is currently meeting all federal air quality 

standards and since diesel trends are expected to continue 

downward with the introduction of new vehicle standards, more 

stringent program requirements such as lower cutpoints cannot be 

justified at this time. 

There are more effective ways, such as on-road enforcement, to 

identify high-emitting vehicles rather than lowering cutpoints. 

Light-duty Diesel Vehicles Fail Rates 

Light-duty engine technology is separated into naturally aspirated (40% 

opacity cut point), which is considered an older technology, and the 

newer turbo-charged (35% opacity cut point) technology which started in 

1990. The 1992 MY is somewhat arbitrarily established as the year when 

turbo-charged engine design was well understood and dominant. The 

results of approximately 19,500 light-duty opacity inspection tests in 2001 

are presented in the following table: 

2001 LDDV Failure Rate 

Failures ---- --- Technology & Total Valid Percent of 

Age Tests Fleet #Failed %ofFieet %ofFailed 

NA.< 92 2,600 13.4% 1ffi 0.8°/( 68.9% 

NA.> 92 338 1.?0/( 30 02% 13.4% 

TC<92 2,000 10.3% 40 02% 17.7% 

TC>92 14,500 74.6% Ne:gigible 0.0% 0.0% 

Totals 19,438 100.0% 226 1.2% 100.0% 

IV-21 
Chapter IV: Diesel Inspection and Maintenance 

Naturally Aspirated Naturally aspirated vehicles have an exhaust plume that is basically black 

Vehicles at the 40% opacity (passing) standard. Naturally aspirated vehicles are 

15% of the fleet and represent 82% of the failed vehicles. Few naturally 

aspirated vehicles are being produced and fewer yet are being operated 

along the Front Range. Review of failures at lower cut points for all 

naturally aspirated vehicles suggests not much improvement in the 

technology in newer vehicles. 

Turbo-charged Turbo-charged vehicles have an exhaust plume that is basically black at 

Vehicles the 35% opacity (passing) standard. Turbo-charged vehicles are 85% of 

the fleet and represent 18% of the failed vehicles, mostly from the pre1992 vehicles. 

Heavy-duty Diesel Vehicles Fail Rates 

Heavy-duty engine technology is separated into naturally aspirated (35% 

opacity cut point), which is considered an older technology, and the 

newer turbo-charged (20% opacity cut point) technology, which started in 

1990. The 1992 MY is somewhat arbitrarily established as the year when 

turbo-charged engine design was well understood and dominant. The 

results of approximately 26,000 light-duty opacity inspection tests in 2001 

are presented in the following table: 

2001 HDDV Failure Rates 

Failures 

Technology & Total Valid Percent of 

Age Tests Fleet #Failed %of Fleet %of Failed 

NA.< 92 900 3.5% 87 0.3% 27.8% 

NA.> 92 225 0.9% 34 0.1% 10.9% 

TC<92 7,300 28.4% 110 0.4% 35.1% 

TC>92 17,300 67.2% 82 0.3% 26.2% 

Totals 25,725 100.0% 313 1.2% 100.0% 

Naturally Aspirated Naturally Aspirated Vehicles have an exhaust plume that is basically 

Vehicles black at the 35% opacity (passing) standard. Naturally aspirated 

vehicles are 5% of the Fleet and represent 40% of the failed vehicles. 

Few naturally aspirated vehicles are being produced and fewer yet are 

being operated along the Front Range. 

Review of failure rates at lower cut points for all naturally aspirated 

vehicles suggests the technology in newer naturally aspirated vehicles 

has not improved with time. The data indicate a significantly higher fail 

rates for older and newer vehicles in the DOIP compared to the DFSCP, 

suggesting a need for better maintenance/repair for the DOIP vehicles 

IV-22 
Chapter IV: Diesel Inspection and Maintenance 

and/or improved testing methods and procedures in the DFSCP. 

Turbo-charged Turbo-charged vehicles have an exhaust plume that is wispy black at the 

Vehicles 20% opacity (passing) standard. Turbo-charged vehicles are 95% of the 

fleet and represent 60% of the failed vehicles. Based on review of the 

failures at lower cut points, newer vehicles fail at approximately onequarter (DFSCP) to one-third (DOIP) of the rate that older vehicles fail, 

suggesting improvement in turbo-charged technology. As was the case 

with naturally-aspirated HDDV, the data indicate a higher fail rate for 

older and newer vehicles in the DOIP compared to the DFSCP. 

Impact of Adjusting Smoke Opacity Limits 

The fail rates of diesel vehicles during CY 2001 at different opacity cut 

points has been analyzed by the APCD staff for the DOIP and DFSCP 

by vehicle technology and age. The results are presented in the following 

table. 

Impact of Adjusting Smoke Opacity Limits 

- 2001 Diesel Opacity Inspection Program FleetDOIP I-Tests 40% 35% 30% 20% 15% 10% 

Class 

DOIP 

LD/NA 

<92 2,600 6% 11 % 19% 28% 38% 53% 71 % 

.:=: 92 338 9% 14% 18% 23% 28% 43% 66% 

DOIP 

LD/TC 

<92 2,000 2% 7% 13% 23% 36% 59% 

.:=: 92 14,500 0% 2% 4% 7% 14% 30% 

DOIP 

HD/NA 

<92 600 14% 21 % 27% 37% 50% 70% 

.:=: 92 125 26% 31 % 35% 42% 56% 67% 

DOIP 

HD/TC 

<92 3,700 2% 10% 29% 

.:=: 92 8,200 1% 3% 8% 

IV-23 
Chapter IV: Diesel Inspection and Maintenance 

Self-Cert 

Class 

HD/NA 

< 92 

~ 92 

HD/TC 

< 92 

~ 92 

Impact of Adjusting Smoke Opacity Limits 

- 2001 Diesel Self Certification Fleet -

1-Tests 40% 35% 30% 25% 20% so 

300 1% 3% 12% 16% 53% 

100 1% 3% 6% 6% 26% 

3,600 1% 21 % 

9,100 0% 5% 

NOTES and EXPLANATION: 

-This information was requested for comparison and analysis purposes. 

-These data are applicable to the Colorado full-load lugdown test cycle. 

10% 

70% 

41 % 

42% 

11 % 

-Opacity limits are the horizontal axis, with vehicle classes on the vertical axis 

-I-Tests= the number of initial emissions tests deemed valid for the class 

(representative of the size of the affected fleet) 

-LD = Light-duty Vehicle = < 7,500 #empty weight; HD = Heavy-duty Vehicle = > 7,500 

# empty weight 

-NA = Naturally Aspirated (i.e. non-turbocharged); TC =Turbocharged 

-<92 = Model years 1991 and earl ier; ~92 = Model years 1992 and newer 

-Shaded boxes denote existing opacity limits e.g. HD fTC opacity limit is 20% 

-Statute currently prohibits opacity limits less than 20%; any change to less than 20% 

requires legislation. 

IV-24 
Chapter V. Off-Road Diesel Vehicles 

Overview 

As noted in Chapter II , changes in off-road (Tier 1) emissions standards 

passed in 1994 were phased in between 1996 and 2000. The standards 

adopted in 1998 (Tier 2) are being phased in between 2001 and 2005. 

The manufacturer's improvements in technology to meet and exceed Tier 

1 standards and the continued growth in equipment population and 

activity has served to slightly reduce PM-1 0 emissions growth and flatten 

NOx emissions growth through 1999. 

Current EPA In 2001 EPA assessed the standards adopted in 1998 for non-road diesel 

standards engines, in particular to determine if the Tier 3 portion (and the Tier 2 

emissions standards for engines under 50 hp) were, indeed feasible. 

Based on information to date, EPA has affirmed the feasibility of these 

standards. This has been reinforced by the certification data from the 

Tier 1 engines in the power ranges of interest that demonstrate many of 

the engines are already meeting Tier 2 standards. 

The 1998 rule did not establish a new Tier 3 program for PM emissions 

reductions because of critical unresolved issues connected with the 

appropriate test procedure for characterizing transient operating 

conditions. Instead the EPA made a commitment in the rule to establish 

an effective program for controlling PM emissions beyond the limited 

control achieved under Tier 2 standards, and to consider adopting 

measures to better ensure in-use emissions control in-use. 

The recent regulations that dramatically reduce on-road diesel emissions 

leaves the non-road diesel engines, already a significant source of PM 

and NOx, as a dominant source of these emissions in the future. The 

emissions trend curves for PM and NOx for on-road and off-road engines 

for the Denver metro area presented in Chapter II of this report affirms 

this observation. 

V-1 
Chapter V: Off-Road Diesel Vehicles 

Future EPA The EPA is preparing proposed rulemaking in 2002 for further reduction 

Rulemaking of PM (and NOx if warranted) through a "systems" approach that 

regulates off-road diesel engines and fuel, similar to the recent on-road 

regulations. This approach continues the pattern of modeling off-road 

emissions reduction 

programs after on-road programs, with some additional lead time 

pro"vided for adaptation of on-road technologies to off-road applications. 

Some analysis of the fuel required to complement the "system" 

envisioned above indicates a 15 -30 ppm sulfur content, which is 

definitely in the range of the ultra-low sulfur fuel required for the on-road 

fleet in 2006. However, in 2007 a new HDDV will be 15 times cleaner 

than a off-road engine under the current Tier 3 off-road standards. The 

lead time allowed for adaptation of on-road technologies will be important 

in determining the timing of the impact of the yet to be proposed new 

regulations. The impact at this time could be estimated to be seen in 10-

15 years depending on the rulemaking process and equipment turnover. 

Opportunities The turnover of diesel engines can take many years because of the 

exist to reduce durability and long life of diesel engines. However, there are still 

emissions opportunities to reduce emissions from the in-use engines through proper 

maintenance, reductions in engine idling, accelerated retirement, add-on 

equipment retrofits, which are facilitated by the availability of ultra low 

sulfur fuel, and use of cleaner diesel fuels. 

Recommendations 

The Work Group is cognizant of the changes in on-road and off-road 

standards, the future trends and the related impacts. There does not 

appear to be any local regulatory action that would be considered 

appropriate at this time for the off-road sector. However, there does 

appear to be opportunities for voluntary activities to encourage the retrofit 

of equipment as broadly defined in the EPA's Voluntary Diesel Retrofit 

Program. 

Some questions or observations of the work group are related to 

emissions inventory development issues, the amount of low sulfur (500 

ppm) currently used in the metro area, incentives for retrofit programs 

and the need for some recognition for those entities that are doing their 

part to improve air quality. 

To take advantage of these opportunities to reduce diesel emissions in 

innovative ways, the Diesel Stakeholder Work Group recommends the 

following : 

V-2 
Chapter V: Off-Road Diesel Vehicles 

Recommendation #1 Include off-road fleets and engines in the Fleet Outreach and 

Awareness Program to encourage voluntary initiatives by fleet and 

engine operators to reduce diesel emissions from the current in-use 

equipment. 

As noted above there are currently off-road fleet and engine operators 

that are planning or implementing voluntary programs that reduce 

emissions from existing diesel equipment. Public recognition of those 

programs can provide an incentive for others to consider similar 

programs. 

Implementation -The fleet special recognition program is outlined in 

Chapter Ill. All elements offer an opportunity for inclusion of off-road 

equipment in one way or another. 

Recommendation #2 Improve the understanding of the current use of low sulfur fuel and 

the population of off road diesel equipment in the Denver metro 

area. 

There is an opinion by Work Group members that there is a significant 

percentage of low sulfur fuel used in the metro area although there is also 

a significant amount high sulfur fuel sold. Also, there is a concern about 

the emissions inventory when equipment population and activity levels 

are compared with fuel sales. 

Implementation -A survey of fuel use/sales and equipment 

population/activity in the metro area is necessary to resolve the 

questions. The Colorado Contractors Association (CCA) has indicated 

that it could assist in collecting this kind of data. The APCD/RAQC will 

investigate additional sources of information and develop inventories. 

Recommendation #3 Based on the need, investigate incentives to encourage the use of 

low sulfur fuel (500 ppm) and other low emitting fuels and 

investigate the possibilities of early introduction of ultra-low sulfur 

fuels (15 ppm). 

Depending on the results of the survey discussed above investigate the 

incentives (economic, recognition, or regulatory) for encouraging the use 

of low sulfur (500 ppm) and other low emitting diesel fuels, such as 

biodiesel. Ultra-low sulfur (15 ppm) diesel fuels is necessary to fully 

realize the benefits of after market emissions control equipment. The 

availability and lead time for introduction of ultra-low sulfur fuel is an 

important consideration. 

Implementation- The RAQC will lead a cooperative effort including the 

Colorado Contractors Association, Environmental Defense, local refiners , 

EPA Voluntary Retrofit Program staff and other interested parties to 

address these issues. 

V-3 
Chapter V: Off-Road Diesel Vehicles 

Recommendation #4 Encourage best management practices regarding engine 

maintenance, idling, and use, similar to the best maintenance 

practices program developed for on-road fleets. 

Equipment manufacturer's representatives are very aware of the 

importance of best management practices and often offer training for 

their clients. Many operating entities currently follow a variety of 

enlightened management practices. 

Implementation- Using the model program described for on-road 

vehicles in Chapter Ill , develop an off-road diesel engine best 

management practices program. The development of a clearinghouse for 

information and outreach to smaller operators is an additional avenue. 

Recommendation #5 Encourage low-emitting fuels, retrofits, and other low-emitting 

technology in large-scale construction projects. 

Large construction projects offer the opportunity to include in contract 

specifications the requirement or requirement with incentives of lower 

sulfur fuels, other low emitting fuels, retrofits, early retirement or 

replacement of existing equipment, or the use of equipment meeting the 

latest standards . 

Implementation- An outreach program to state and local agencies and 

large corporate entities in the region concerning the possibilities of 

improvements to heath and air quality in the region through encouraging 

these activities. 

V-4 
Appendix A 
Appendix A 

National and Local Voluntary Diesel Retrofit Pilot Programs 

s ource: www.epa.gov. ota ,. retro 1t. 

Retrofit Number of 

State City/State Entity Retrofits Technology Committed 

AL Birmingha nc am School District Catalyst 35 

I CA I State of California Agricultural Pumps I Engine Re-~ower 430 

CA State of California Bay Area, South Coast, Santa Early engine retirement 6901 Barbara, San Diego 

CA State or BP Fuel Transport Trucks Particulate Filter, Low 29 Sulfur Fuel 

CA State of California CARS School Bus Retrofit Program Particulate Filter, Low 1900 Sulfur Fuel 

CA State of California CAL TRANS - California Department I 

of Transportation Low Sulfur Fuel 14000 

CA State of California Ralph's Grocery Company Particulate Filter, Low 20 Sulfur Fuel 

CA State of California I Urban Transit Agencies I Particulate Filter, Low 4500 Sulfur Fuel 

CA Los Angeles I City of Los Angeles I Particulate Filter, Low 2300 Sulfur Fuel 

CA Los Angeles I Hertz Equipment Fleet I Particulate Filter, Low 20 Sulfur Fuel 

,... Los Angeles Los Angeles City Sanitation Particulate Filter, Low v, 15 Sulfur Fuel 

'""'Angeles I Los Angeles Count:t II Low Sulfur Fuel 160 

CA Los Angeles I Metro Transit Authority I Particulate Filter, Low 20 Sulfur Fuel 

CA Los Angeles School Districts - Los Angeles, Particulate Filter, Low 39 Anaheim Union, Hemet Unified Sulfur Fuel 

....,,... '"' ...... I San Diego School District I Particulate Filter, Low ...,.,, ..... rego 30 Sulfur Fuel 

CA San Diego Various private and transit fleets Particulate Filter, Low 6000 Sulfur Fuel 

CT State of I CT Transit Agency I Particulate Filter, Low 390 Connecticut Sulfur Fuel 

[;]I Washington I WMATA- Washington Metropolitan Particulate Filter, Low 1460 Area Transit Authority Sulfur Fuel 

G Various oxides of 

Atlanta Hartsfield International Airport nitrogen (NOx) 10 

technologies 

rn Rnic:.P Arl::. r.n, 1ntv Hiahwav Distrir:t lr.::~t::~lvst I nw Sttlfttr Fttf>ll :l9 I 

A-1 
Appendix A 

IL Chicago I Locomotive Switch Yard I Auxiliary Power ur~il_ J: 7 

IN II Hammond I Hammond City School District Catalyst 25 

MA Boston Mass Turnpike Authority Catalyst 220 

MA Boston I Mass Baz: Area Transit I Low Sulfur Fuel 475 

MA Woburn Waste Management Catalyst 40 

I s~ ....... uf New NJ Jersey NJ Transit Authority Low Sulfur Fuel 2000 

State of New Various oxides of 

NJ Jersey Department of Transportation nitrogen (NOx) 30 

technologies 

II NV Las Vegas Construction equipment Catalyst 100 

NY New York New York City Transit Authority Particulate filter, Low 4400 Sulfur Fuel 

NY New York New York City DOS Particulate Filter, Low 260 Sulfur Fuel 

[;] New York New York City School Bus Fleet Particulate Filter, Low 1000 Sulfur Fuel 

[;] Westchester Westchester County DOT Particulate Filter, Low 360 County Sulfur Fuel 

OH Cleveland Community Transit Particulate Filter, Low 10 Sulfur Fuel 

PA Philadelphia Area School District Particulate Filter, Low 120 Sulfur Fuel 

PA Philadelphia U.S. Naval Base I Unknown I 10 

PA Philau"''l-'' ,;a 

Southeastern Pennsylvania Transit Particulate Filter, Low 1300 Authority Sulfur Fuel 

..-~ Houst City of Houston Various NOx 29 technologies 

Fuel emulsion, selective 

TX Houston Port of Houston Authority f-atalytic reduction (SCR), 59 

Low Sulfur Fuel 

Various oxides of 

TX State of Texas Various Transit Agencies & nitrogen (NOx) & 10000 Construction Companies particulate matter (PM) 

technologies 

WA Seattle Transit, School District & City Particulate Filter Catalyst I 5000 I Vehicles Low Sulfur Fuel 

TOTAL NUMBER OF RETROFITS COMMITTED: 70,229 

A-2 
Appendix A 

Summary of National and Local Voluntary Diesel Retrofit Pilot Programs 

San Diego School Bus Project location: San Diego, Calif. 

Retrofit Demonstration 

Program Project participants: San Diego Unified School District, ARCO Products, 

Engelhard, Johnson Matthey, Inc. , Navistar, 

California Air Resources Board, and South Coast Air 

Quality Management District 

Project date: 

Project funding: 

Retrofitted equipment: 

Retrofit devices: 

Retrofit technology: 

Emissions reductions: 

Future: 

January 1999 -June 2000 

Federal/State and Industry 

30 Navistar Diesel School Buses 

ARCO's Emission Control Diesel (ECD) fuel 

California Air Resources Board (CARS) fuel 

Continuously Regenerating Technology (CRT) 

Diesel Particulate Filter (DPX) 

Johnson Matthey CRT System- an emission control 

system combining oxidation catalyst and filter 

Engelhard DPX System -a catalytic soot filter for 

controlling PM emissions (replaces muffler) 

ARCO ECD fuel- ultra low sulfur diesel fuel 

(contains only 15 parts per million of sulfur as 

opposed to 500 parts per million in diesel) 

CRT System- 90 percent particulate matter (PM) 

removed along with hydrocarbons (HC) and carbon 

monoxide (CO) 

DPX System- 90 percent PM, 80 percent HC, and 

80 percent CO emissions reduction 

Since the program ended in June, the San Diego 

School District has implemented a plan to discard 

375 buses older than 1977. In addition the district 

has equipped 10 of their buses with the particulate 

traps and two others with the traps and engines to 

fully cut emissions. An additional 1,875 buses will 

have filters installed to reduce emissions. 

Sources: US EPA web site- www.epa.gov/otaqlretrofitlexsandiego.htm, Diesel 

Technology Forum web site- www.dieselforum.org, and Education Week web sitewww.edweek.org. 

A-3 
The "Big Dig" or The 

Boston Central 

Artery/Tunnel 

Voluntary Diesel 

Retrofit Program 

Project location: 

Project participants: 

Project date: 

Project funding: 

Appendix A 

Boston, Mass. 

Massachusetts Turnpike Authority (MTA), 

Massachusetts Department of Environmental 

Protection (DEP), and the Northeast States for 

Coordinated Air Use Management (NESCAUM) 

September 1998 - December 2004 

Massachusetts Highway Department has and will 

continue to provide funding to contractors to 

purchase emission control devices. 

Retrofitted equipment: 70 large, off-road diesel construction machines used 

for the construction of the "Big Dig" project such as 

front-end loaders, bulldozers, backhoes, cranes, air 

compressors, and excavators. 

Retrofit devices: 

Retrofit technology: 

Catalytic converters 

Particulate filters 

Oxidation Catalyst- used to reduce diesel emissions 

by oxidizing diesel pollutants, such as PM , HC, and 

CO, to less harmful emissions such as H20 and C02. 

Diesel Particulate Filters- used to control PM 

emissions 

Emissions reductions: Approximately 3 tons per year for PM, 12 tons per 

year for HC, and 36 tons per year for CO. Project 

sponsors estimate that they will reduce 203 tons of 

pollutants over the six-year project period. 

Future: 

Other: 

Due to the air quality benefits achieved thus far, the CA/T Project 

will continue to require that all off-road diesel equipment be 

equipped with oxidation catalysts until the end of the project. 

In addition to retrofit technology, the project has required all 

contractors to minimize diesel emissions impacts on people 

living and working near the construction zones by: 

~ turning off diesel combustion engines on construction 

equipment not in active use and on dump trucks that are idling 

while waiting to load or unload material for five minutes or more; 

~ establishing a staging zone for trucks that are waiting to load or 

unload material at the work zone in a location where diesel 

emissions from the trucks will not be noticeable to the public; and 

~ locating construction equipment away from sensitive receptors 

such as fresh air intakes to buildings, air conditioners, and 

windows. 

Sources: US EPA web site- www.epa.gov/otaq/retrofitlexbigdig.htm, The Big Dig 

A-4 
Appendix A 

The New York City Project location: New York, N.Y. 

Transit (NYCT) Clean 

Diesel Vehicle Air Project participants: NYC Transit Authority, NYS DEC, Johnson Matthey. 

Inc., Corning, Inc., Equilon Enterprises LLC, 

Environmental Canada, and Emissions Research 

and Measurement Division 

Quality Project 

Project date: 

Project funding: 

Retrofitted equipment: 

Retrofit devices: 

Retrofit technology: 

Emissions reductions: 

Future: 

February - November 2000 

New York State Environmental Bond Act 

50 New York City Transit urban diesel buses 

Continuously Regenerating Technology (CRT) 

combined with reduced sulfur diesel fuel 

Johnson Matthey CRT System- an emission control 

system combining oxidation catalyst and filter to 

reduce PM emissions to compressed natural gas 

(CNG) levels 

CRT System combined with reduced sulfur diesel 

fuel- up to 90 percent reduction in PM , HC, and CO 

The project sponsors concluded that the use of very 

low sulfur diesel was a key component to the 

outcome. Due to the success in reductions of the 

three pollutants, the NYCT has continued the 

program. 

Sources: US EPA web site - www.epa.gov/otaqlretrofitlexnyproject.htm, Diesel 

Technology Forum web site- www.dieselforum.org, and DieseiNet web sitewww. dieselnet.com. 

A-5 
Diesel Solutions Project location: 

Project participants: 

Project date: 

Project funding: 

Retrofitted equipment/ 

devices/technology: 

Appendix A 

Seattle, Wash . 

The Puget Sound Clean Air Agency, U.S. 

Environmental Protection Agency Region 10, King 

County, City of Seattle, Boeing, Everett Public 

Schools & Durham Transportation, Pacific Rim 

Enterprise Center & Emerald City Disposal, 

Washington State Department of Transportation, Port 

of Seattle, Tosco Refining, Washington State 

Department of Ecology, The Diesel Technology 

Forum, Manufacturers of Emission Controls 

Association (MECA), Cummins, Detroit Diesel 

Corporation, Johnson Matthey, Inc., and CleanAIR 

Systems. 

Began in Summer/Fall 2001 

EPA has leveraged about $1 million in funding to 

support this program. More grant funding is expected 

over the next several years. EPA's Diesel Retrofit 

project is providing substantial grant funding and 

technical support to help implement the program. 

Other funding partners include the Puget Sound 

Clean Air Agency , the Washington State Department 

of Ecology and Region 10 of EPA 

The below equipment is equipped with particulate filter traps and 

oxidizing catalysts in conjunction with Tosco Refining ultra-low sulfur 

diesel fuel. 

King County- 1,100 diesel-powered buses will use ultra-low sulfur 

diesel between 2001 and 2003; 800 buses will be equipped with retrofit 

hardware over the next 2 %years; new vehicle and equipment 

purchases will come equipped with ultra-low sulfur diesel emission 

hardware 

City of Seattle -switch to ultra-low sulfur diesel throughout its diesel 

fleet; switch to ultra-low sulfur diesel in its fueling stations; retrofit heavyduty diesel fleet beginning in 2001 and finishing in 2003 

Boeing -fuel 70 heavy-duty diesel fleet vehicles with ultra-low sulfur 

diesel; equip 70 heavy-duty diesel trucks with retrofit hardware; 

demonstrate viability of retrofit hardware and fuel to other private sector 

fleet operators 

Everett Public Schools and Durham Transportation- equip 25-30 

International DTA 360, Cummins B series, and Caterpillar 3126 B school 

buses with retrofit technology; refuel buses with ultra-low sulfur diesel 

fuel 

A-6 
Appendix A 

Emerald City Disposal and the Pacific Rim Enterprise Center- equip 

25-30 refuse trucks with retrofit technology; refuel trucks with ultra-low 

sulfur diesel fuel 

The Washington State Department of Transportation -develop pilot 

project to install retrofit technology on highway maintenance vehicles in 

Northwest region; refuel vehicles with ultra-low sulfur diesel fuel 

Port of Seattle- develop program to install retrofit technology on diesel 

vehicles associated with its expansion project at Sea-Tac Airport; refuel 

diesel vehicles using ultra-low sulfur diesel fuel 

Emissions reductions: The program coordinators expect to see at least a 90 

percent reduction in fine particle emissions, more 

than a 90 percent reduction in toxic emissions, and 

undetectable levels of HC emissions using the retrofit 

devices combined with the ultra-low sulfur diesel fuel. 

Future: The program will continue for the next few years with 

other private and public partners joining. 

Sources: US EPA web site- www.epa.gov/otaqlretrofitlexeverettwa.htm, Puget 

Sound Clean Air Agency web site -

www.pscleanair.org/dieselsolutionslindex.shtml, and Diesel Technology Forum 

web site - www.dieselforum.org/retrofitlpublicprivate.html. 

A-7 
Ralph's Grocery 

Company EC~Diesel 

Truck Fleet Start-up 

Experience 

Project location: 

Project participants: 

Project date: 

Project funding: 

Retrofitted equipment: 

Retrofit devices: 

Retrofit technology: 

Emissions reductions: 

Appendix A 

Riverside, Calif. 

ARCO Products, U.S. Department of Energy, 

National Renewable Energy Laboratory, Detroit 

Diesel Corporation, Engelhard, Johnson Matthey, 

California Air Resources Board, South Coast Air 

Quality Management District, California Energy 

Commission, and the U.S. Environmental Protection 

Agency 

March 2000- February 2001 

U.S. Department of Energy 

20 - 1999 Sterling Class 8 with Detroit Diesel Series 

60 engines 

ARCO's Emission Control Diesel (ECD) fuel 

California Air Resources Board (CARB) fuel 

Continuously Regenerating Technology 

Diesel Particulate Filter (DPX) 

Five trucks operating on CARB fuel without a filter 

Five trucks operating on ECD fuel without a filter 

Five trucks operating on ECD fuel with Engelhard 

DPX 

Five trucks operating on ECD fuel with Johnson 

Matthey CRT 

Final results and evaluation for this project is 

expected before the end of the first quarter 2002. 

However results from the first five months are as 

follows: 

The trucks equipped with the catalyzed particulate 

filters and ECD fuel emitted 91-99 percent less 

particulate matter compared to the CARS-fueled 

trucks with no filter equipment. 

Sources: Report issued by DOE- www.afdc.doe.gov/pdfs!Ralphs_ECD.pdf and the 

Diesel Technology Forum web site - www.dieselforum.org. 

A-8 
California Air Project location: 

Resources Board's 

(ARB) Lower-Emission Project participants: 

School Bus Program 

Project date: 

Project funding: 

Retrofitted equipment: 

Retrofit technology: 

Emissions reductions: 

Append ix A 

California 

California Energy Commission, South Coast Air 

Quality Management District, Bay Area Air Quality 

Management District, Monterey Bay Unified Air 

Pollution Control District, San Diego County Air 

Pollution Control District, Sacramento Metropolitan 

Air Quality Management District, and the San 

Joaquin Valley Unified Air Pollution Control District 

2001 - 2002 school year 

$50 million in state funds to California EPA's Air 

Resources Board, who will distribute grants to school 

districts 

2,000 diesel school buses for retrofit technology and 

350 pre-1976 diesel school buses to be replaced 

Engelhard Diesel Particulate Filter (DPX) and 

Johnson Matthey CRT System- $12.5 million, new 

alternative fuel buses (primarily natural gas)- $25 

million, new, cleaner diesel buses- $12.5 million. All 

buses equipped with filters are required to use ultralow sulfur fuel. 

The program began with the 2001 school year in 

August and will continue through summer of 2002. 

Program administrators expect to see at least 85 

percent reductions in PM. 

The ARB staff estimates that this program will reduce 

PM emissions by approximately 150 tons from the 

year 2001 - 2010. This equals about 82 pounds per 

day. 

Sources: California Air Resources Board web site- www.arb.ca.gov. 

A-9 
New York State Project location: 

Thruway Truck Stop 

Electrification (TSE) 

Pilot Program Project participants: 

Project date: 

Project funding: 

Technology: 

Emissions reductions: 

New York State ThruwayDeWitt and Chittenango Travel Plazas (near 

Syracuse) 

Appendix A 

New York State Thruway Authority, New York State 

Energy Research and Development Authority 

(NYSERDA), and Niagara Mohawk 

2001-2003 

$500,000 shared by the NYS Thruway Authority , 

NYSERDA, and Niagara Mohawk Power 

Corporation. 

44 Truck Stop Electrification (TSE) units 

manufactured by ldleAir Technologies Corporation in 

Knoxville, Tenn. 

These stand-alone electrical power hookups provide 

drivers with local television, basic cable, telephone 

service, and basic internet service. Drivers will have 

easy access to the above services by swiping a credit 

card into a module that easily fits into their window. 

TSE units will help reduce both air and noise 

pollution. The program will continue through 2003. 

Emissions reductions have not yet been determined. 

However, according to the Argonne National 

Laboratory, a single truck engine idles an average of 

six hours a day and 1 ,830 hours per year. It is 

estimated that a single truck emits an estimated 220 

pounds of nitrogen oxide and 380 pounds of CO 

each year. 

In addition to air quality benefits, installing the TSE 

units at the two demonstration sites alone could 

reduce diesel fuel usage by 470,000 gallons per year, 

according to a NYS Thruway press release. 

Sources: New York State Thruway Authority web site -www.thruway.state.ny.us. 

A-10 
International Truck and School bus distribution: 

Engine CorporationGreen Diesel Distribution dates: 

Technology School 

Buses Funding: 

Technology: 

Emissions reductions: 

Appendix A 

Several California school districts 

December 2001 - March 2002 

School districts apply for state grants from the 

California Low Emission School Bus Program to 

replace old buses with new Green Diesel Technology 

buses. 

The Green Diesel Technology buses use catalyzed 

diesel particulate filters and BP's low-sulfur diesel 

fuel in combination with an engine, built by 

International, designed to lower diesel emissions. 

The Green Diesel Technology buses achieve a 90 

percent reduction in PM and HC emissions. In 

addition, the odor associated with diesel fuel is 

eliminated and the buses use 40- 60 percent less 

fuel per mile. 

Sources: International web site- www.internationaldelivers.com, Green Diesel 

Technology web site- www.greendieseltechnology.com. 

Regional Project location: 

Transportation 

District's (RTD) Emissions inspections: 

Emissions Inspections 

and Electric Mall 

Shuttles 

Retrofit: 

Other: 

Seven-county metropolitan Denver area 

All buses tested annually to insure they meet State 

and RTD standards, which are twice as strict as State 

standards. 

Supervisors make on-street visual evaluations which 

may result in immediate removal from service if State 

standards are exceeded. Vehicles are scheduled for 

repair within five days of reported violations. 

RTD opts to replace old engines with advanced, 

clean-burning, low emission, electronically-controlled 

engines from Detroit Diesel and Cummins. The 

engines reduce PM emissions by 70 percent. RTD 

has replaced 830 buses over the past five years 

(about 2/3 of its fleet). The oldest bus in operation is 

a 1991 bus. 

Hybrid/CNG Mall Shuttles- RTD pioneered transit 

use of electric vehicles in 1982 on the 161

h Street 

Mall. There are currently 34 running today. RTD is 

researching the use of hybrid-electric buses to 

replace the existing shuttles in the future. Hybridelectric buses contain a clean-burning, CNG-fueled 

engine, which drives an electric generator. 

Sources: RTD web site- www.rtd-denver.org. 

A-11 
FedEx Express - Low Project date: 

Emission Vehicle 

Purchases Project funding: 

Affected equipment: 

Technology: 

Emission reductions: 

FedEx Express and the Project participants: 

Alliance for 

Environmental 

Innovation- The 

Future Vehicle Project Project date: 

Technology: 

Emissions reductions: 

Future: 

A-12 

Appendix A 

July 1999 to present 

FedEx Corp. with assistance from Colorado sales tax 

waiver 

106 diesel-fueled package delivery vehicles in the 

last 2-1/2 years. About 80 percent of Fed Ex's new 

vehicle purchases in the Denver-Boulder area have 

been certified Low Emission Vehicles (LEV). With a 

fleet of 449 vehicles in the area, nearly 25 percent 

are now Low Emission ehicles. 

Modified Cummins engines certified for LEV 

Up to 25 percent reduction in NOx emissions 

compared to current non-LEV vehicles. 

FedEx Express, Alliance for Environmental 

Innovation (an initiative of Environmental Defense), 

Allison Transmission Division of General Motors, 

BAE SYSTEMS Controls, and Eaton Corporation. 

Prototype testing begins October 2002; new delivery 

trucks on road by 2004 

Three competing teams, headed by the companies 

listed above, will develop prototype diesel-electric 

delivery vehicles for the next generation of FedEx 

Express delivery trucks. The prototypes will be 

tested in October against a current baseline 1999 

diesel delivery truck. 

FedEx Express and Alliance for Environmental 

Innovation asked companies to submit proposals for 

a diesel-electric delivery truck that will increase fuel 

efficiency by 50 percent and reduce PM and NOx 

emissions by 90 percent. 

FedEx Express expects to have the new delivery 

trucks on the road by 2004