State ofUtah 

Department of 

Environmental Quality 

Dianne R. Nielson, Ph.D. 

Executive Director 

DIVISION OF AIR QUALITY 

Richard W. Sprott 

Director 

Apri112, 2006 

Richard Long 

US EPA REGION 8 

JON M. HUNTSMAN, JR. 

Governor 

GARY HERBERT 

Lieutenant Governor 

999 18th Street Suite 300 

Mail Code: SP-AR 

Denver, CO 80202-2466 

Dear Mr. Long: 

RE: Utah Diesel liM State Implementation Plan (SIP) 

DAQP-017-06 

On February 6, 1996, Governor Leavitt submitted the Utah Diesel liM SIP to Region VIII for 

approval. In its review, Region VIII staff recently identified the following deficiencies in our 

initial submittal: 

1. The 20% program credit in the SIP attributable to the diesel inspection and 

maintenance (liM) program is not defensible and no scientific basis has been provided 

either in the SIP or its technical appendices. 

2. There are no set opacity limits indicated in the SIP. 

3. EPA cannot approve locomotive requirements or idling ordinances. 

4. The SIP appendices are incomplete and marked DRAFT. 

5. Opacity limits, equipment and test specifications, inspection procedures and cutpoints 

are not defined. 

When the SIP was submitted, Utah led the nation in establishing an effective diesel liM 

program for heavy-duty and light-duty diesel vehicles. Other liM jurisdictions have benefited 

from Utah's diesel liM program experience in establishing their programs. Since 1996, 

Utah's liM counties have finalized their respective regulations and ordinances. The Society 

of Automotive Engineers (SAE) has finalized its J-1667 Snap Acceleration Smoke Test 

Procedure for Heavy-Duty Powered Vehicles. J-1667 is used by many states and other 

jurisdictions and is available from the California Air Resources Board at 

http://www.arb.ca.gov/msprog/hdvip/saej1667.pdf. To facilitate your staffs review, the 

150 North 1950 West • PO Box 144820 • Salt Lake City, UT 84114-4820 • phone (801) 536-4000 • fax (801) 536-4099 

T.D.D. (801) 536-4414 • www.deq.utah.gov 
• DAQP-017-06 

April )1., 2006 

finalized test procedures and specifications are attached. These specifications include the 

opacity limits for each vehicle type. 

Over the past several years, UDAQ staff have endeavored to work with EPA staff to establish 

a reasonable credit for our light and heavy duty diesel 11M programs. While the 20% credit 

initially requested may have been ambitious, we believe the attached study clearly justifies 

granting a minimum of a 2% SIP credit for reducing on-road diesel PMIO exhaust emissions. 

This request is also consistent with EPA's emphasis on the public health benefits gained from 

reducing diesel exhaust emissions. Denying Utah SIP credit eliminates any incentive to 

integrate future diesel On-board Diagnostics (OBD) testing into our 11M programs and 

conflicts with EPA's substantial investment in diesel retrofit and idling reduction technology 

throughout the nation. The anticipated promulgation of a more stringent fine particulate 

standard will require program areas to evaluate the effectiveness of a variety of control 

measures, including further controls on diesel vehicles. Diesel 11M programs were effective 

in identifying modified and tampered vehicles, which is a growing issue due to the increased 

availability of aftermarket 'performance' devices. Not granting any SIP credit for a diesel 

11M program seems counter to the EPA's priorities and sends an inconsistent message to the 

public and program administrators. As a consequence of not being granted any program 

credit, Utah County suspended its diesel 11M program. 

UDAQ requests that EPA review the attached data and finalize its rulemaking on the subject 

submittal. If you have any questions, feel free to call Joe Thomas at (801) 536-4175. 

Sin eM 

~dW.S rott 

cc: Margo Oge 

RWS/BC/kd 

Attach: 

1. Davis County Diesel 11M program regulation, equipment specification and test 

procedure 

2. Salt Lake County Diesel 11M program regulation, equipment specification and test 

procedure 

3. Utah County Diesel 11M program regulation, equipment specification and test 

procedure 

4. Diesel 11M program effectiveness study 

2 
DAQP-017-06 

April 12, 2006 

5. Reply to "EPA Comments on Utah's 'Particulate Matter (PM) Exhaust Emissions 

Reductions from Diesel Inspection and Maintenance (I/M) Programs in Utah (Davis, 

Salt Lake and Utah Counties)'", January 20, 2005. 

6. Regulatory Amendments to California's Heavy-Duty Vehicle Inspection Program and 

Periodic Smoke Inspection Program (Technical Support Document) 

7. Multiple Smoke Opacity Measurements as Indicators of Particulate Emissions for 

Heavy-Duty Diesel Vehicle Inspection and Maintenance Programs 

8. FAX to Ran Macdonald (UDAQ) from Mark Carlock (CARB, October 23, 2003) 

3 
DAVIS COUNTY 

ORDINANCE No. 06-98 

AN ORDINANCE AMENDING THE DIESEL VEHICLE EMISSIONS INSPECTION 

MAINTENANCE PROGRAM ORDINANCE (ORDINANCE NO. 05-94) DATED 

DECEMBER 15, 1994, BY REPLACING APPENDIX E ESTABLISHING CRITERIA FOR 

DETERMINING VEHICLES REQUIRING ENHANCED 1/M PROGRAM TESTING. 

The Board of County Commissioners of Davis County, Utah, in a regular meeting, lawful 

notice of which has been given, finds that and that it is in the best interest of the County that this 

ordinance be adopted. 

THEREFORE, the Board of County Commissioners of Davis County, Utah, ordains as 

follows: 

Section 1. Ordinance No. 05-94 Amended. 

The Diesel Vehicle Emissions Inspection/Maintenance Program Ordinance (Ordinance 

No. 05-94) dated December 15, 1994, is hereby amended by replacing Appendix E establishing 

criteria for determining vehicles requiring enhanced inspection/maintenance program testing. 

The new Appendix E is attached to this ordinance and incorporated herein by reference. 

Section 2. Conflicts 

This ordinance supersedes all prior ordinances, resolutions and policies of Davis County 

to the extent they are in conflict with the specific provisions hereof. In all other respects such 

prior ordinances, resolutions and policies shall remain in full force and effect. 

Section 3. Effective Date 

This ordinance is necessary for the immediate preservation of the peace, health or safety 

of the county and its inhabitants and therefore shall take effect immediately upon publication in 

one issue of a newspaper published and having general circulation in Davis County. 

This ordinance was unanimously and duly adopted by the Board of County 

Commissioners of Davis County, Utah on the 23rd day of December, 1998, with Commissioners 

Carol R. Page, Gayle A. Stevenson, and Danny R. McConkie voting in favor of the ordinance. 

Board of County Commissioners of Davis County 

By: ______________ _ 

Dannie R. McConkie, Chairman 

Attachment 1 

! 

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ATTESTED BY: 

Margene Isom 

Davis County Clerk/ Auditor 

Publication Date: December 31, 1998 

Approved to as form: 

Deputy Davis County Attorney 
·, 

DIESEL VEHICLE EMISSIONS INSPECTION/MAINTENANCE 

PROGRAM ORDINANCE 

TABLE OF CONTENTS 

SECTION 

1.0 Definitions .................................................................................................................. 2 

2.0 Purpose ....................................................................................................................... 7 

3.0 Jurisdiction of the Division ........................................................................................ 7 

4.0 Powers and Duties ...................................................................................................... 8 

5.0 Scope .......................................................................................................................... 10 

6.0 General Provisions ..................................................................................................... 1 0 

7.0 Standards and Specifications for Diesel Testing Equipment.. ................................... 14 

8.0 Permit Requirements for Diesel Inspection/Maintenance Program Fleet Stations .... 16 

9.0 Approval ofRequired Test Equipment ...................................................................... 19 

10.0 Certification Requirements for Testing and Permitting of Applicants for Diesel 

Opacity Inspectors ..................................................................................................... 19 

11.0 Inspection Procedure .................................................................................................. 21 

12.0 Certificates of Compliance ........................................................................................ 23 

13.0 Certificates ofWaivers .............................................................................................. 24 

14.0 Temporary Waivers ................................................................................................... 26 

15.0 Engine Changes ......................................................................................................... 26 

16.0 Right to Appeal .......................................................................................................... 27 

17.0 Penalty ........................................................................................................................ 27 

18.0 Severability ................................................................................................................ 28 

19.0 Effective Date ............................................................................................................ 28 

APPENDICES 

APPENDIX A 

APPENDIXB 

APPENDIXC 

APPENDIXD 

APPENDIXE 

Cutpoints ............................................................................................ 30 

Fee Schedule ...................................................................................... 31 

Diesel Opacity Inspection Equipment Specifications ........................ 33 

Diesel Vehicle Opacity Inspection Procedures .................................. 34 

Penalty Schedule ................................................................................ 35 
1.0 DEFINITIONS 

For the purpose of this Ordinance, the following terms, phrases, and words shall have the 

following meanings, unless otherwise defined: 

1.1 Accuracy: is the degree of conformity of a measure to a standard or a true value. 

1.2 Basic Engine Systems: are those parts or assemblies which provide for the 

efficient conversion of diesel fuel into useful power to include, but not limited to, 

valve train mechanisms, cylinder heads, block, piston-ring-cylinder sealing 

integrity and post-combustion emissions control devices. 

1.3 Calibration: is the process of establishing or verifying the accuracy of test 

equipment. 

1.4 Certificate of Compliance: is the document which indicates that the smoke 

opacity levels from a diesel vehicle complies with applicable smoke opacity limits 

at the time of the inspection or after needed adjustments or repairs and reinspection. 

1.5 Certificate ofWaiver: is a document, issued by the Division, used to verify that a 

vehicle has met the repair or adjustment requirements of the Diesel Vehicle 

Emissions Inspection /Maintenance Program Ordinance even though specific 

standards have not been met. 

1.6 Certification: is assurance by an authorized source, whether it be the Federal 

Government, a laboratory, the manufacturer, the State, or the Division, that a 

specific product or statement is, in fact, true and meets all applicable 

requirements. 

1. 7 Certified Neutral Density Filter: is an optical quality filter which reduces the 

amount of transmitted light, an amount which is dependent upon the filter's 

optical density rating, uniformly across the visible light spectrum for the purpose 

of verifying the accuracy of the Diesel Opacity Analyzer. 

1.8 County: is Davis County, Utah. 

1.9 Chassis Dynamometer or Dynamometer: is a vehicle power absorption device 

which has the ability to approximate or simulate actual on-road operation of 

motor vehicles through the application of variable loading. 
1.10 Clean-Out Cycle: is the wide open throttle accelerations used to purge the 

exhaust system of any residual exhaust prior to an Opacity Inspection applicable 

to Heavy Duty Diesel Vehicles. 

1.11 Cutpoints: are the maximum allowable smoke opacity limits for a given weight 

class and model year of a motor vehicle, as determined by the Division, using an 

approved Diesel Opacity Analyzer. 

1.12 Dedicated Printer: is the printer on the approved Diesel Opacity Analyzer which 

is used solely to print Certificates of Compliance. 

1.13 Diesel I/M Program Fleet Station: is a private or public fleet, of twenty five (25) 

or more vehicles, that has a valid permit, issued by the Division, to perform 

Diesel Opacity Inspections on their own vehicles in accordance with the Diesel 

Vehicle Emissions Inspection/Maintenance Program Ordinance. 

1.14 Diesel Opacity Inspector: is an individual, employed by the Division or licensed 

by the Division, to perform Opacity Inspections on diesel vehicles. 

1.15 Diesel Opacity Inspection: is an inspection of a diesel powered vehicle by a 

Diesel Opacity Inspector, employed by a Diesel I/M Program Fleet Station, or the 

Division. 

1.16 Diesel Opacity Inspector's Permit: is the permit issued by the Division to a 

Diesel Opacity Inspector after completing the required training course and passing 

all aspects of the practical hands-on and written test procedures. 

1.17 Diesel Opacity Analyzer: is an opacity meter with any additional hardware or 

software required by the Division to perform an official Diesel Opacity Inspection 

in accordance with this Ordinance. 

1.18 Diesel Powered Motor Vehicle: includes only a motor vehicle which is operated 

with four wheels or more on the ground, propelled by a compression-ignited 

engine using diesel fuels. 

1.19 Diesel Vehicle Inspection/Maintenance Program: means the opacity inspection 

and repair program for diesel powered vehicles established by the Division, 

pursuant to Section 41-6-163.8, Utah Code Annotated 1953, as amended. 

1.20 Director: means the Director of the Environmental Health and Laboratory 

Division of the Davis County Health Department or his or her authorized 

representative. 
1.21 Division: means the Environmental Health and Laboratory Division of the Davis 

County Health Department and the people employed there-in. 

1.22 Drift: refers to the amount that the Diesel Opacity Analyzer readings change, 

expressed as a percentage of full scale, over a period of time. 

1.22.1 Zero Drift: refers to no change of the zero reading when the Diesel 

Opacity Analyzer is in the zero mode. 

1.22.2 Span Drift: refers to the amount of change in reading when the Diesel 

Opacity Analyzer is in the span or full field mode. 

1.23 Emissions Control Systems: are those parts, assemblies or systems originally 

installed by the manufacturer in or on a vehicle for the specific purpose of 

reducing exhaust emissions. 

1.24 Engine Rated RPM: means a specific rpm at which the manufacturer states that 

the engine's maximum/rated brake horsepower is attained. Above this rpm, the 

engine's governor will typically begin limiting full load fuel quantity and thus 

prevent the engine from developing full power beyond this rpm. Rated engine 

power and speed information is usually found on a label affixed to the engine 

itself or other underhood location. 

1.25 Exemption Form: is a document used to verify that a vehicle is exempt from the 

testing and repair/adjustment requirements of this Ordinance. 

1.26 F AS: means Free Acceleration Smoke pertaining to engine accelerations at wide 

open throttle (WOT) with no load on the engine. 

1.27 GVWR: (Gross Vehicle Weight Rating) means the weight specified by the 

vehicle manufacturer as the maximum allowable loaded weight of a single 

vehicle. 

1.28 Heavy Duty Diesel Vehicle: as applicable to the Diesel Vehicle Inspection/ 

Maintenance Program refers to diesel vehicles with 16,001 pounds GVWR or 

more. 

1.29 High Altitude Specifications: are tune-up specifications that have been provided, 

by the manufacturer, to the Environmental Protection Agency for vehicles 

operating 4,000 feet or more above sea level. 
1.30 Idle Mode: is the condition where the vehicle engine is at operating temperature 

and running at an RPM rate specified by the manufacturer's curb idle speed, 

where the engine is not propelling the vehicle, and where the throttle is in the 

closed or idle stop position. This condition must be achieved without placing a 

load on the engine to decrease the RPM to the specified rate. 

1.31 Inspection Area: is the area that is occupied by the Diesel Opacity Analyzer, test 

equipment, and the vehicle being inspected. 

1.32 ISO: means International Standards Organization. 

1.33 Light Duty Diesel Vehicle: as applicable to the Diesel Vehicle Inspection/ 

Maintenance Program refers to diesel vehicles with 16,000 pounds GVWR or 

less. 

1.34 Maximum No-Load RPM or High Idle RPM: means the maximum rpm that the 

engine's governor will allow the engine to attain under no-load, wide open 

throttle (WOT) conditions. For many vehicular diesel engines, this rpm is 

typically 8 to 11% higher than the engine's rated rpm. 

1.35 Motor Vehicle: is a self propelled motorized vehicle with an internal combustion 

powered engine which is licensed for operation on public roads and/or streets. 

Motor Vehicles exempted from the inspection requirements of this Ordinance are 

listed in Section 6.4 of this Ordinance. 

1.36 MPH: means Miles Per Hour. 

1.3 7 MSO: means Manufacturer's Statement of Origin, Manufacturer's Certificate of 

Origin, or similar such document accompanying each newly manufactured 

vehicle, provided by the new vehicle manufacturer. 

1.38 Non-Certified Inspector: is any person who has not been licensed by the Division 

to perform official Diesel Opacity Inspections. 

1.39 Off Highway Vehicles: are vehicles licensed to operate exclusively off highways. 

1.40 Opacity: means the degree to which the exhaust plume obscures the view 

expressed in percentage of obstruction, or the degree, expressed in percent, to 

which transmittance of light is reduced by the exhaust plume. 

1.41 Opacity Meter: means an optical instrument which is designed to provide 

continuous real-time measurement of the opacity of diesel exhaust gases and 

particulates which pass through the optical unit. 
1.42 Opacity Inspection: means the testing of diesel powered motor vehicles using 

procedures prescribed in this Ordinance in order to determine the magnitude 

(expressed as a percentage) of obscured light (opacity) due to exhaust 

constituents, mainly fine particles. 

1.43 Original Condition: is the condition of the emission control system(s) as installed 

by the manufacturer, but not necessarily to the original level of effectiveness. 

1.44 PM10: means particulate matter with an aerodynamic diameter less than or equal 

to a nominal ten micrometers as measured by an EPA reference or equivalent 

method. 

1.45 Permit: is a document, issued by the Division, to a person or facility granting 

them authority to perform Diesel Opacity Inspections in accordance with this 

Ordinance. 

1.46 Primary Residence: is the place which an individual lives more than six ( 6) 

months during a calendar year. 

1.47 Publicly-Owned Vehicles: are motor vehicles owned by a Government entity, 

including but not limited to the Federal Government or any agency thereof, the 

State of Utah or any agency or political subdivision thereof. 

1.48 Repeatability: is the instrument's capability to provide the same value, within 

specified tolerances, for successive measurement of the same sample. 

1.49 RPM: means Revolutions Per Minute as pertaining to engine crankshaft speed. 

1.50 SAE: means Society of Automotive Engineers. 

1.51 Safety Inspection Certificate: is a certificate issued to a vehicle after it has been 

inspected and passed an official Utah Highway Patrol Safety Inspection 

performed by a licensed safety inspection station. 

1.52 Strip Chart Recorder: is an instrument which receives and records data from one 

or more electrical inputs and displays that information in the form of a real-time, 

continuous (non-impact) tracings on paper. 

1.53 Technical Bulletin: is a document, issued to Opacity Inspectors and/or Diesel 11M 

Program Fleet Stations by the Division to update, clarify or establish policies 

and/or procedures for their implementation in the Diesel Vehicle Inspection/ 

Maintenance Program. 
1.54 Technical Centers: are those facilities operated by the Division for technical or 

administrative support of the Gasoline Inspection/Maintenance Program and 

Diesel Vehicle Inspection/Maintenance Program. 

1.55 Temporary Waiver: is a Waiver that may be issued by the Director which will 

allow the temporary registration of a vehicle based upon a vehicle owner's 

compliance with the conditions ofthe Waiver. 

1.56 Training Program: means a formal program, administered, conducted, or 

approved by the Division, for the education of Diesel Opacity Inspectors in basic 

emission control technology, inspection procedures, diagnosis and repair of 

emissions related problems, Diesel 1/M Program policies, procedures, and this 

Ordinance. 

1.57 WOT: means Wide Open Throttle. 

2.0 PURPOSE 

It is the purpose of this Ordinance to reduce PM10 air pollution levels by requiring annual 

inspections of both light duty and heavy duty in-use diesel powered motor vehicles and by 

requiring emission related repairs/adjustments for those vehicles that fail to meet prescribed 

standards so as to: 

2.1 Protect and promote the public health, safety and welfare; 

2.2 Improve air quality; 

2.3 Comply with the Utah Air Quality Board requirements under subsection 26-13-

6(8); and 

2.4 Comply with the law enacted by the Legislature of the State of Utah, section 41-

6-163.8 Utah Code Annotated, 1953, as amended. 

3.0 JURISDICTION OF THE DIVISION 

All aspects of the Diesel Vehicle Emission Inspection/Maintenance Program within 

Davis County shall be subject to the direction and control of the Division. 
4.0 POWERS AND DUTIES 

4.1 The Division shall be responsible for the enforcement and administration of this 

Ordinance and any other powers vested in it by law and shall: 

4.1.1 Require the submission of information, reports, plans, and specifications 

from Diesel I/M Program Fleet Stations as necessary to implement the 

provisions, requirements, and standards of this Ordinance; 

4.1.2 Issue permits, certifications, and charge fees as necessary to implement the 

provisions, requirements and standards of this Ordinance; 

4.1.3 Perform inspections (audits) of any Diesel I/M Program Fleet Station, 

issue orders and/or notices, hold hearings, levy administrative penalties, 

and negotiate consent agreements as necessary to carry-out the purposes of 

this Ordinance; 

4.1.4 Take samples and make analysis required to ensure that the provisions of 

this Ordinance are met; and 

4.1.5 Make policies and procedures necessary to ensure that the provisions of 

this Ordinance are met and that the purposes of this Ordinance are 

accomplished. 

4.2 The Division may suspend, revoke, negotiate a consent agreement in lieu of a 

suspension, or deny a permit of a Diesel I/M Program Fleet Station and/or require 

the surrender of permits issued under the provisions of this Ordinance and 

surrender of unused Certificates of Compliance issued to a Diesel liM Program 

Fleet Station upon showing that: 

4.2.1 A vehicle was inspected and issued a Certificate of Compliance by Diesel 

I/M Program Fleet Station personnel, and at the time of inspection, the 

vehicle did not comply with the applicable requirements of this ordinance; 

4.2.2 A Diesel I/M Program Fleet Station allowed a Certificate of Compliance 

to be issued to a vehicle without an approved inspection being performed; 

4.2.3 The station personnel violated any provision of this Ordinance, or any 

Division policy properly promulgated for the operation of a Diesel I/M 

Program Fleet Station; 
4.2.4 The station was not equipped as required by section 8.4.5 of this 

Ordinance; 

4.2.5 The station was not operating from a location specified on the permit; 

4.2.6 A Diesel Opacity Inspection was performed by an individual that at the 

time of the inspection did not hold a valid Diesel Opacity Inspectors 

Permit; 

4.2.7 The station denies access, or fails to permit a representative of the 

Division to conduct an audit and/or inspection or conduct other necessary 

activities or business during regular business hours; 

4.2.8 A vehicle was inspected and issued a Certificate of Compliance by a 

Diesel I/M Program Fleet Station that, at the time of inspection, exceeded 

permissible opacity levels as set forth in this Ordinance. 

4.3 The Division may suspend, negotiate a consent agreement in lieu of suspension, 

revoke, or deny the Permit of a Diesel Opacity Inspector and require the surrender 

of this Permit upon showing that: 

4.3.1 The Diesel Opacity Inspector issued a Certificate of Compliance for a 

vehicle without performing a Diesel Opacity Inspection approved by this 

Ordinance on that vehicle; 

4.3.2 The Diesel Opacity Inspector denied the issuance of a Certificate of 

Compliance for a vehicle that, at the time of the inspection, complied with 

this Ordinance; 

4.3.3 The Diesel Opacity Inspector issued a Certificate of Compliance for a 

vehicle that, at the time of issuance, was in such condition that it did not 

comply with this Ordinance; 

4.3.4 The Diesel Opacity Inspector knowingly allowed a Non-Certified 

Inspector to perform a Diesel Opacity Inspection, or any portion of a 

Diesel Opacity Inspection; 

4.3.5 The Diesel Opacity Inspector signed an inspection form or Certificate of 

Compliance indicating that he/she had performed the inspection when, in 

fact, he/she had not performed an inspection complying with the 

requirements of this Ordinance; 

4.3.6 The Diesel Opacity Inspector signed a Certificate of Compliance prior to 

an inspection being performed. 
4.4 The Division shall respond, according to policies and procedures, to public 

complaints regarding the integrity of inspections performed at Diesel liM 

Program Fleet Stations. 

4.5 The Division, or the Division's authorized representative, is responsible for 

performing all Opacity Inspections on Light Duty Diesel Vehicles. 

4.6 The Division is responsible for administering all aspects of the Heavy Duty Diesel 

Opacity Inspections. 

4.6.1 The Division may perform periodic Opacity Inspections, during normal 

business hours, on any vehicle that has or will be inspected by a Diesel 

liM Program Fleet Station. 

4.6.2 Heavy Duty Diesel Vehicles that are not included as part of a Diesel liM 

Program Fleet Station may be inspected by the Division. Inspections may 

be performed at the Division facilities or at another specified location. 

5.0 SCOPE 

It is unlawful for any person not to comply with any policy, procedure, Technical 

Bulletin, or Regulation relating to diesel emissions control, promulgated by the Federal 

Government, the State, the Davis County Health Department, or the Division, unless 

expressly waived by this Ordinance. 

6.0 GENERAL PROVISIONS 

Subject to the exceptions described in section 6.4 and pursuant to the schedule in 

section 6.1 and 6.1.1, individuals with their primary residence in Davis County must 

register their vehicles in Davis County and diesel powered motor vehicles that are or will 

be registered in Davis County, or operated from a facility within Davis County, shall be 

subject to a Diesel Opacity Inspection performed by a Diesel liM Program Fleet Station, 

a Division operated test facility or other entity approved by the Director. 

6.1 Beginning December 15, 1994 a Certificate of Compliance or Waiver, or 

evidence that the motor vehicle is exempt from the Diesel 1/M Program 

requirements (as defined in section 6.4) shall be presented to the Davis County 

Assessor or the Utah State Tax Commission and the Air Pollution Control Fee 

paid as conditions precedent to annual registration or annual renewal of 

registration of a motor vehicle. 

6.1.1 The beginning date listed herein may be temporarily postponed if it is 

deemed necessary by the Director to aid in the smooth and effective 

implementation of the Diesel Vehicle Inspection/Maintenance Program. 
The temporary postponement of the program beginning date may be 

implemented if it is determined by the Director that the integrity of the 

program may be jeopardized because testing equipment, procedures, 

facilities, software or other aspects of the program are not ready for 

effective and accurate testing to begin. Different start-up dates may be 

selected for light duty and heavy duty vehicles. 

6.2 A Certificate of Compliance or Waiver issued to a dealer licensed with the State 

of Utah and issued in the dealer's name, shall be valid for registration purposes 

for a period of six months as specified in section 41-3-28.5, Utah Code 

Annotated, 1953, as amended. The purchaser's name, address, and phone number 

shall be recorded by the dealer on the back of the Certificate. 

6.3 Vehicle fleet owners shall comply with the Diesel Vehicle Inspection/ 

Maintenance Program requirements pursuant to a schedule determined by the 

Division. Federally-owned vehicles and vehicles of employees operated on a 

federal installation that do not require registration in the State of Utah shall 

comply with the Diesel Vehicle Inspection/Maintenance Program requirements 

pursuant to a schedule determined by the Division. 

6.4 The following vehicles are exempt from this Ordinance: 

6.4.1 All agricultural implements of husbandry not registered for highway use; 

6.4.2 Any vehicle used for maintenance or construction and not designed or 

licensed to operate on the highway; 

6.4.3 Any vehicle registered exclusively as an Off Highway Vehicle; 

6.4.4 Any new vehicle being sold for the first time that has a valid MSO 

(Manufacturers Statement of Origin) form. 

6.5 Owners of private or publicly owned Heavy Duty Diesel vehicles may request 

that a Division representative perform an on-site Diesel Opacity Inspection at a 

location other than a County owned test facility. On-site inspections by the 

Division shall only be performed in accordance with the following requirements: 

6.5.1 On-site Diesel Opacity Inspections shall only be performed when there are 

five (5) or more vehicles at one test site. These vehicles may be owned by 

different individuals. 
6.5.2 All vehicle owners must provide proof to the Division that the vehicle has 

passed a Utah Highway Patrol safety inspection within a two (2) month 

period previous to the date of the requested emissions inspection. 

6.5.3 All test sites must comply with local zoning ordinances for the 

performance of these inspections and be approved by the Division prior to 

inspections being performed. 

6.5.4 On-site Diesel Opacity Inspections for emergency response vehicles will 

not be subject to a minimum number of vehicles at one location and may 

be allowed a zoning variance if necessary to allow tests to be performed at 

their location. 

6.6 Required tools and equipment as noted in section 8.4.5, supplies, records, unused 

Certificates of Compliance, and other required forms, shall be kept at the Diesel 

I/M Program Fleet Station at all times and shall be available for inspection or 

collection by the Division at any time the Diesel I/M Program Fleet Station is 

open for business. 

6.6.1 Records of completed inspections and duplicate copies of Certificates of 

Compliance issued shall be kept at the Diesel I/M Program Fleet Station at 

all times for a period of not less than eighteen ( 18) months and shall be 

available for inspection or collection by the Division at any time the 

Diesel I/M Program Fleet Station is open for business. 

6.6.2 A periodic inspection and audit shall be made by a Division representative 

to verify compliance with this Ordinance for each Diesel I/M Program 

Fleet Station. As part of the periodic inspection and audit of the Diesel 

I/M Program Fleet Station the Division representative shall, as applicable, 

observe the performance of an electronic equipment calibration performed 

by the Diesel Opacity Inspector, perform equipment calibrations and 

voltage correlations, examine calibration records and Certificates of 

Compliance as well as other required reports, forms, or records to verify 

that the use of these items are in compliance with this Ordinance and the 

policies and procedures of the Division. 

6.6.3 During the station inspection and audit by the Division, the Division 

representative shall have exclusive access to the Diesel Opacity Analyzer. 
6.6.4 The Division representative may check the accuracy of the Diesel Opacity 

Analyzer using Division audit procedures to verify that the equipment is 

reading within the tolerances established by the Division. Diesel Opacity 

Analyzers not reading within the audit tolerances shall be recalibrated to 

within acceptable tolerances or be placed "out of service". 

6. 7 FEES: The fees assessed upon Diesel 1/M Program Fleet Stations and the Diesel 

Opacity Inspectors shall be determined according to the fee schedule adopted by 

the Davis County Commission. The fee schedule as referenced in Appendix B to 

the Ordinance may be amended by the Davis County Commission as is deemed 

necessary to accomplish the purpose of this Ordinance. 

6. 7.1 Diesel emissions inspection fees shall not exceed the amounts specified in 

Appendix B. If a vehicle fails the inspection the owner is entitled to one 

reinspection for the reinspection fee specified in Appendix B if the owner 

returns to the Division within thirty (30) days from the date of the initial 

inspection. The Division shall extend the thirty day reinspection time to 

accommodate the vehicle owner if the Division is unable to schedule the 

retest of the vehicle within the thirty day time period. Subsequent 

inspections of failed vehicles and tests of failed vehicles after thirty days 

will be charged the original inspection fee. 

6. 7.2 Duplicate Certificates of Compliance or Waiver may be issued to a vehicle 

owner/operator within two months of the initial test, fees for the duplicate 

certificate may not exceed the amount specified in Appendix B. 

6.8 VEHICLE IDLING LIMITATION. It shall be unlawful for any owner or 

operator of any Heavy Duty Diesel Vehicle to cause or permit the same to be 

idled for a period in excess of fifteen (15) consecutive minutes, or for a period in 

excess of forty-five (45) minutes in any one hundred-twenty (120) minute period 

(it being the intent of this provision that an owner or operator may not circumvent 

the provisions of this section by repeated turning on and off of a diesel engine). 

6.8.1 EXEMPTION TO IDLING LIMITATIONS. Vehicles may be exempted 

from the idling limitation requirements of Section 6.8 under the following 

conditions: 

(a) To supply power to a refrigeration unit for the purpose of cooling 

the contents of a trailer. 
(b) To provide heat or air conditioning to a sleeper unit of the vehicle 

or to occupied buses. 

(c) Emergency response vehicles. 

6.8.2 Vehicles exempted from the Vehicle Idling Limitations as applicable 

under Section 6.8.1 (a), (b) of this Ordinance shall not remain in an idling 

condition for a period longer than fifteen (15) consecutive minutes, or for 

a period in excess of forty-five (45) minutes in any one-hundred-twenty 

(120) minute period if located within five hundred (500) feet of any 

residence. 

7.0 STANDARDS AND SPECIFICATIONS FOR DIESEL TESTING EQUIPMENT 

7.1 No Diesel Opacity Inspection required by this Ordinance shall be performed 

unless the type of instrument used for measuring exhaust opacity from diesel 

powered motor vehicles is contained in the list of approved test equipment as 

provided by the Division. The test equipment shall meet the requirements of the 

equipment specifications referenced in Appendix C of this Ordinance. The test 

equipment shall be in good working condition, shall comply with calibration 

requirements of the Division, and shall be operated according to manufacturer's 

specifications and operating procedures. 

7.2 Any test equipment being used to perform Diesel Opacity Inspections shall be 

registered with and approved by the Division and, if required, shall bear a 

registration sticker issued by the Division. Registration stickers are not 

transferable or assignable. Any new or used test equipment put in use after 

station approval must be approved by the Division before use. Test equipment 

used temporarily during times of breakdown or repair of the registered equipment 

do not require a registration sticker but shall meet all other requirements of this 

section including the approval of the Division before being used to perform Diesel 

Opacity Inspections. 

7.3 The test equipment printers shall be maintained in such a manner that the printing 

of the test results shall be clearly visible on all copies. If any printer fails to 

properly function, then the station shall discontinue testing until the required 

repairs have been performed. 

7.4 It shall be unlawful for any person to modify the hardware or the software of an 

approved Diesel Opacity Analyzer without written application and written 

approval by the Division. 

7.5 Documentation, Logistics, and Warranty Requirements. 
7.5.1 Instruction Manual: An instruction manual shall accompany each Diesel 

Opacity Analyzer and shall contain at least the following information for 

the analyzer: 

(a) A complete technical description; 

(b) The functional mechanical and electrical schematics; 

(c) The accessories and options that are included and/or available; 

(d) The model number, identification marking and location; 

(e) Operating maintenance including daily, weekly, and monthly 

accommodations for maintaining sample system integrity 

including, but not limited to, leaks, hang-up, calibration and filters. 

The services to be performed only by the manufacturer shall be 

clearly identified; 

(f) Information concerning the nearest service facility where the 

equipment can be serviced; and 

(g) The warranty provisions for the analyzer, including a list of 

warranty repair stations by name, address and telephone number. 

7.5.2 The analyzer shall be maintained in accordance with the manufacturer's 

recommended maintenance schedule and records of maintenance service 

shall be maintained for examination by the Division. 

7.6 Calibration of Diesel Opacity Analyzers: 

7.6.1 A Diesel Opacity Inspector shall perform a mechanical/electrical 

equipment calibration on the Diesel Opacity Analyzer following 

the manufacturer's recommended procedures not more than three 

(3) days prior to an official Diesel Opacity Inspection. Said 

calibration will be performed with a known source of laboratory 

certified light absorbing material such as a Certified Neutral 

Density Filter or other device approved by the Division. 

7.6.2 A Diesel Opacity Inspector shall perform an electrical zero and 

span check on the Diesel Opacity Analyzer following the analyzer 

manufacturer's procedures prior to each official Diesel Opacity 

Inspection. A Diesel Opacity Analyzer that fails the zero and span 

check shall be cleaned or recalibrated following manufacturer's 

recommendations. 
7.6.3 If the Diesel Opacity Analyzer requires repairs in order to be used 

in accordance with this Ordinance, the Diesel liM Program Fleet 

Station shall discontinue use of the Diesel Opacity Analyzer and 

notify the Division that the analyzer is "Out-of-Service" and shall 

again notify the Division after repairs are made and before testing 

is resumed. 

7.6.4 The Diesel Opacity Analyzer instruction manual and other 

Division approved information shall be reviewed by the Diesel 

Opacity Inspector to ensure that proper procedures are being used 

for performing the calibration check. 

8.0 PERMIT REQUIREMENTS FOR DIESEL INSPECTION/MAINTENANCE 

PROGRAM FLEET STATIONS 

Owners of vehicle fleets with twenty five (25) or more Heavy Duty Diesel 

Vehicles may apply to the Director for a Diesel liM Program Fleet Station permit. This 

permit would allow fleet owners to inspect only their own vehicles that are registered to 

the individual or corporation identified on the permit. 

8.1 The Director is authorized to issue or deny Diesel I/M Program Fleet Station 

permits. 

8.2 No Diesel liM Program Fleet Station permit may be assigned, transferred, or used 

by any person other than the original owner identified on the Diesel liM Program 

Fleet Station permit. The Diesel liM Program Fleet Station permit shall be posted 

in a conspicuous place within public view on the premises. 

8.3 The Diesel liM Program Fleet Station must be at a permanent location which 

meets all applicable zoning requirements to provide for the inspection of diesel 

vehicles, as licensed, and as defined in this Ordinance. 

8.4 Application for a Diesel liM Program Fleet Station permit shall be made to the 

Division on a form provided by the Division. No Diesel liM Program Fleet 

Station permit shall be issued unless the Director finds that the facilities, tools and 

equipment ofthe applicant comply with the requirements of this Ordinance and 

that competent personnel, certified under the provisions of section 1 0.0, are 

employed and will be available to make inspections, and the operation thereof 

will be properly conducted in accordance with this Ordinance. 

8.4.1 Each Diesel liM Program Fleet Station will assign one individual, either a 

manager or an Inspector, the responsibility of resolving any problems or 
addressing any concerns that a Division representative may identify. The 

selected individual or his/her representative will be at the Diesel 1/M 

Program Fleet Station and available during normal business hours. The 

selected individual's name and title will be listed on the Diesel 1/M 

Program Fleet Station permit application form. 

8.4.2 A Diesel 1/M Program Fleet Station shall immediately notify the Division 

and immediately surrender all unused Certificates of Compliance at such 

time as the Diesel 1/M Program Fleet Station no longer employs a Diesel 

Opacity Inspector. 

8.4.3 A Diesel 1/M Program Fleet Station shall notify the Division whenever 

five (5) or more consecutive Diesel Opacity Inspections are scheduled to 

be performed within an eight (8) hour period. The Director, at his 

discretion, may dispatch a field auditor to observe all of or a portion of the 

Diesel Opacity Inspections performed. 

8.4.4 A Diesel 1/M Program Fleet Station shall comply with all terms stated in 

the permit application and all the requirements of this Ordinance. 

8.4.5 As a condition for permitting all Diesel 1/M Program Fleet Stations, the 

following tools shall be available for performance of the inspection and 

maintenance of diesel powered motor vehicles: 

(a) A Division approved Diesel Opacity Analyzer that meets the 

minimum specifications as outlined in APPENDIX C of this 

Ordinance; 

(b) A Division approved personal computer capable of meeting the 

minimum specifications as outlined APPENDIX C of this 

Ordinance; 

(c) A handbook, approved by the Division, that includes testing 

procedures to be followed by the Diesel Opacity Inspector; 

(d) An accurate strip chart recorder or other recording device capable 

of recording Diesel Opacity Inspection data for analysis; 

(e) Reference manuals specified and approved by the Division that 

contain tune up specifications, and information covering the 

emissions control systems for the model years and makes of 

vehicles involved in the Diesel Vehicle Emissions Inspection/ 

Maintenance Program; 
(f) Sufficient hand tools for proper performance of inspection and 

maintenance of the vehicle; 

(g) Exhaust gas removal equipment approved by the Division; 

(h) The Diesel Opacity Analyzer manufacturer's maintenance and 

calibration manual which must remain in the inspection area; 

(i) All forms, Technical Bulletins, and other information materials 

provided by the Division. 

8.4.6 All facets of the Diesel Vehicle Emissions Inspection/Maintenance 

Program shall be performed by the Diesel Opacity Inspector including: 

(a) Diesel Opacity Inspection equipment preparation, and calibration 

checks; 

(b) Exhaust sampling and analysis for the purpose of a Diesel Opacity 

Inspection for issuance of a Certificate of Compliance; 

(c) Preparation of reports, forms, certificates; and 

(d) All other aspects of the official Diesel Opacity Inspection 

including but not limited to: the tampering inspection, inserting or 

attaching the exhaust opacity sampling equipment, hooking up the 

tachometer, entering the data, preconditioning the vehicle, and 

signing Certificates of Compliance and inspection forms. 

8.4.7 A Diesel I/M Program Fleet Station shall be kept in good repair and in 

safe condition for inspection purposes free of obstructions and hazards. 

8.5 PERMIT DURATION AND RENEWAL 

8.5.1 Diesel I/M Program Fleet Station Permits shall be issued annually and 

shall expire one year from date of issuance. The Permit shall be 

renewable sixty (60) days prior to the date of expiration. 

8.5.2 It is the responsibility of the owner/operator of the Diesel I/M Program 

Fleet Station to apply in a timely manner for a renewal of Diesel 11M 

Program Fleet Station Permits with the Division. 
8.5.3 Diesel liM Program Fleet Station to hold Division Harmless: In making 

application for a Diesel I/M Program Fleet Station permit or for its 

renewal, such action shall constitute a declaration by the applicant that the 

Division shall be held harmless from liability incurred due to action or 

inaction of Diesel I/M Program Fleet Station's owners or their employees. 

8.5.4 Required permit fees and renewal fees are listed in APPENDIX B of this 

Ordinance. 

8.6 Diesel liM Program Fleet Station Permits are the sole property of the Division. 

Only the license they represent is tendered. Permits may be suspended or revoked 

for violations of this Ordinance. Diesel I/M Program Station Permits obtained 

through fraud or misrepresentation may be deemed to be null and void. 

9.0 APPROVAL OF REQUIRED TEST EQUIPMENT 

10.0 

9.1 Diesel Opacity Inspections required by this Ordinance shall not be performed 

unless the equipment used meets the specifications as defined in the Ordinance 

and as approved by the Division. 

9.2 Any changes to the design or performance characteristics of component 

specifications which may affect the equipment or instrument performance must be 

approved by the Division. It shall be the instrument manufacturer's responsibility 

to confirm that such changes have no detrimental effect on the opacity meter or 

other equipment or instrument performance. 

CERTIFICATION REQUIREMENTS FOR TESTING AND PERMITTING OF 

APPLICANTS FOR DIESEL OPACITY INSPECTORS 

10.1 No person shall perform any part of a Diesel Opacity Inspection for the issuance 

of a Certificate of Compliance or Waiver unless the person possesses a valid 

Diesel Opacity Inspector's Permit issued by the Division. 

10.2 Applications for a Diesel Opacity Inspector Permit shall be made on a form to be 

prescribed by the Division. No Diesel Opacity Inspector Permit shall be issued 

unless the applicant complies with the requirements of this section. 

10.2.1 An applicant shall demonstrate knowledge, skill and competence 

concerning the operation and theory of diesel-fueled internal combustion 

engmes. 
10.2.2 An applicant shall complete a Division approved training course and shall 

demonstrate knowledge, skill, and competence by passing a written and 

performance qualification test including, but not limited to, knowledge of 

the following: 

(a) Knowledge of the Ordinance governing the Diesel Vehicle 

Inspection/Maintenance Program; 

(b) Operation of and proper use, care, maintenance, and calibration of 

the Division approved Diesel Opacity Analyzer; 

(c) Proper use and distribution of the required inspection forms, 

Certificates, calibration records, and supplemental documents, and 

(d) Waiver requirements for all diesel vehicles failing the initial Diesel 

Opacity Inspection. 

10.2.3 Requalification requirements for Diesel Opacity Inspectors. 

(a) Upon determination by the Director of the necessity of updating 

the qualifications for Diesel Opacity Inspectors, they shall be 

required to requalify. Requalification requirements shall be 

determined by the Director. 

(b) Diesel Opacity Inspectors shall be required to recertify annually. 

Failure to recertify within the required period of time shall result in 

the suspension or revocation of the Diesel Opacity Inspector's 

permit as described in this Ordinance. 

10.2.4 The Diesel Opacity Inspector's Permit shall be valid only at the station 

where the Inspector is employed at the time the permit was issued. If the 

Inspector is later employed at another Diesel I/M Program Fleet Station, 

the Inspector shall notify the Division of the employment change. The 

Inspector shall reapply for a permit at the new location and pay the 

required fees. Prior to testing at the new location, the Inspector shall be 

permitted there and a new Permit number shall be issued. This Permit 

shall expire on the same date as the original. 
1 0.2.5 The fee required to obtain a Diesel Opacity Inspector permit and for 

renewal of the permit is listed as part of APPENDIX B of this Ordinance. 

10.3 Permit Expiration 

10.3.1 The Diesel Opacity Inspectors Permit shall be issued annually and shall 

expire one year from the date of issuance. The Diesel Opacity Inspector's 

Permit shall be renewable sixty (60) days prior to the date of expiration. 

1 0.3.2 It is the responsibility of the Diesel Opacity Inspector to pursue the 

renewal of the Permit. 

10.4 The Diesel Opacity Inspector Permit is the sole property of the Division. Only 

the license it represents is tendered. The Division may suspend or revoke the 

permit for violations of this Ordinance. Diesel Opacity Inspector Permits that 

were obtained through fraud or misrepresentation may be deemed null and void. 

11.0 INSPECTION PROCEDURE 

11.1 No Light Duty Diesel Vehicle may receive a Diesel Opacity Inspection unless that 

vehicle has passed an official Utah Highway Patrol Vehicle Safety Inspection as 

required by the law of the State of Utah, section 41-6-158 Utah Code annotated, 

1953, as amended. Proof of the inspection shall be in the form of a valid Safety 

Inspection Certificate issued within the required time period. 

11.2 The Diesel Opacity Inspection shall be performed by a Diesel Opacity Inspector 

who has been certified to perform Diesel Opacity Inspections at the location 

where the inspection is being performed. 

11.3 The entire Diesel Opacity Inspection shall take place within the reach of the 

Diesel Opacity Analyzer's hoses and/or electrical leads. 

11.4 The temperature where testing equipment is operated shall be not less than 41 o 

Fahrenheit and not more than 110 o Fahrenheit during the inspection. 

11.5 The Diesel Opacity Analyzer shall be kept in an area that provides adequate 

protection from the weather, wind, and temperature extremes. 
11.6 The electrical supply to the Diesel Opacity Analyzer shall meet the equipment 

manufacturer's requirements for voltage and frequency stability. 

11.7 The Diesel Opacity Inspector shall not inspect or test any motor vehicle with a 

known mechanical condition which may cause injury to inspection personnel or 

damage to the inspection station or test equipment or which may affect the 

validity of the test, until such condition is corrected. Such conditions include, but 

are not limited to: coolant, oil or fuel leaks, low oil or low fluid levels, and high 

visible emissions. 

11.8 Any time an engine stalls during a Diesel Opacity Inspection, the test shall be 

restarted. If an Inspector cannot complete a test because of continuous stalling, 

fluctuating RPM measurements, or RPM measurements that are not within the 

Division specified parameters, these conditions shall be corrected before the test 

is continued. 

11.9 The Diesel Opacity Inspector shall accurately identify and enter vehicle and 

owner information from the vehicle to be tested as required by the data entry 

process of the Diesel Opacity Analyzer and any other data requirements of the 

Division. 

11.10 Testing vehicles with multiple exhaust outlets require testing each outlet, 

recording the results from the exhaust outlet which emits the highest emission 

levels as the test results for the vehicle. 

11.11 The Diesel Opacity Inspector shall determine the appropriate test procedure to 

follow depending on the vehicle weight rating and type and then proceed with the 

test procedures as outlined in APPENDIX D of this Ordinance. 

11.11.1 If a vehicle is unable to be tested using a particular weight category 

test procedure as outlined in APPENDIX D because of an unusual 

engine/chassis configuration, the Director, at his/her discretion, may 

select an alternate test procedure to be performed on the vehicle. 

11.12 The Division, the Davis County Health Department, Davis County, their officials 

or employees shall not be held responsible for any failure of any vehicle 

component or system occurring during an inspection if proper inspection 

procedures are followed. 
12.0 CERTIFICATES OF COMPLIANCE 

12.1 No person shall make, issue, or knowingly use any imitation or counterfeit 

Certificate of Compliance. 

12.1.1 No person shall knowingly use stolen or counterfeit Certificates of 

Compliance. 

12.2 Certificates of Compliance shall be purchased only from the Division. 

12.3 No refund or credit shall be allowed for unused Certificates of Compliance, 

except as provided in Section 12.9. 

12.4 Purchase of Certificates of Compliance: 

12.4.1 Sales of Certificates of Compliance shall only be made to a representative 

of the Diesel I/M Program Fleet Station possessing an acceptable form of 

identification. 

12.4.2 Certificates of Compliance shall be sold at a cost established by the Davis 

County Commission and referenced in APPENDIX B, in lots to be 

determined by the Division. The Division may limit the number of 

Certificates of Compliance purchased to the number that the Division 

determines can be secured and stored safely. 

12.4.3 Certificates of Compliance shall not be sold, loaned, transferred, or given 

to any other Diesel liM Program Fleet Station, or any other individual or 

entity. The Diesel I/M Program Fleet Station shall at all times account for 

all Certificates of Compliance that have been purchased by the station. 

12.4.4 Certificates of Compliance are solely the property of the Division, only the 

license they represent is tendered. Certificates of Compliance obtained 

through fraud, misrepresentation, and/or improper testing may be deemed 

null and void. 

12.5 A Certificate of Compliance shall not be issued until a vehicle has received a 

Diesel Opacity Inspection conducted according to the requirements of this 

Ordinance. 

12.6 All unused Certificates of Compliance shall be kept in a secure place at all times 

to prevent loss or theft. 
12.7 Certificates of Compliance shall be used m sequential order by Diesel liM 

Program Fleet Stations. 

12.8 Certificates of Compliance found to be missing, stolen, or unaccounted for, shall 

be reported to the Division within twenty four (24) hours and the station shall 

cease performing Diesel Opacity Inspections until the Division reauthorizes the 

station to again resume testing. 

12.9 Upon final cancellation, suspension or revocation of the Diesel I/M Program Fleet 

Station Permit of any station, the station owner, manager or other responsible 

person shall immediately surrender all unused Certificates of Compliance to the 

Division. The Division shall receipt and refund the fee paid for unused 

Certificates of Compliance to the station owner according to the policies of the 

Division. Upon transfer or termination of business ownership, the Diesel liM 

Program Fleet Station permit and all Certificates of Compliance shall be 

immediately surrendered to the Division. Any person acquiring a business that 

has been permitted as a Diesel I/M Program Fleet Station, is prohibited from 

performing Diesel Opacity Inspections under the authority of any such permit or 

from issuing Certificates of Compliance which were issued to the previous owner. 

13.0 CERTIFICATES OF WAIVER 

13.1 No person shall make, 1ssue, or knowingly use any imitation or counterfeit 

Certificate ofWaiver. 

13.1.1 No person shall knowingly use stolen or counterfeit Certificates of 

Wavier. 

13.2 If it is determined by the Director that a particular vehicle can not be tested using 

any current test procedures, the Director may issue a Waiver allowing the vehicle 

to be registered until an alternate test procedure is developed. 

13.3 Certificates of Waiver shall only be issued by the Division unless the Division 

determines other acceptable methods of issuing the Waivers. A Waiver shall only 

be issued after determining that the vehicle complies with the requirements of this 

section for Waiver issuance. 

13.4 A Certificate of Waiver may be issued for Light Duty Diesel vehicles if all of the 

following requirements are met: 

13.4.1 Air pollution control devices that were originally installed by the 

manufacturer are in place and operable on the vehicle. If the devices have 

been removed or rendered inoperable, they shall be replaced or repaired 

before a Waiver is granted. Costs for repairs or replacement of pollution 

control equipment will not be included in Waiver repair costs; 
13.4.2 Any applicable High Altitude Adjustments have been performed following 

the manufacturers recommended procedures; 

13.4.3 The vehicle continues to exceed applicable opacity standards after $750 

(seven hundred and fifty dollars) of acceptable emissions related repairs 

have been performed after the first Diesel Opacity Inspection failure. 

Proof of repair costs shall be provided for the vehicle to the Division in the 

form of a dated, itemized bill, invoice, work order, manifest or statement 

in which emissions related parts are specifically identified. If repairs are 

made by the vehicle owner or by someone who does not possess a valid 

business license for automobile or truck repair, then the cost of labor shall 

not be included in determining the cost of acceptable emission related 

repairs, and; 

13.4.4 Any vehicle that does not experience any improvement in Opacity levels 

since the first Diesel Opacity Inspection shall not be eligible for an 

emissions repair Waiver regardless of the amount spent in attempting to 

repair the vehicle. 

13.5 A Certificate ofWaiver may be issued for Heavy Duty Diesel vehicles if all ofthe 

following requirements are met: 

13.5.1 Air pollution control devices that were originally installed by the 

manufacturer are in place and operable on the vehicle. If the devices have 

been removed or rendered inoperable, they shall be replaced or repaired 

before a Waiver is granted. Costs for repairs or replacement of pollution 

control equipment will not be included in the repair Waiver; 

13.5.2 Any applicable High Altitude Adjustments have been performed following 

the manufacturers recommended procedures; 

13.5.3 The vehicle continues to exceed applicable opacity standards after $1500 

(fifteen hundred dollars) of acceptable emissions related repairs have been 

performed after the first Diesel Opacity Inspection failure. Proof of repair 

costs shall be provided for the vehicle to the Division in the form of a 

dated, itemized bill, invoice, work order, manifest or statement in which 

emissions related parts are specifically identified. If repairs are made by 

the vehicle owner or by someone who does not possess a valid business 

license for automobile or truck repair, then the cost of labor shall not be 

included in determining the cost of acceptable emission related repairs, 

and; 
13.5.4 Any vehicle that does not experience any improvement in Opacity levels 

since the first Diesel Opacity Inspection shall not be eligible for an 

emissions repair Waiver regardless of the amount spent in attempting to 

repair the vehicle. 

14.0 TEMPORARY WAIVERS 

14.1 For all vehicles, if a part or parts which are necessary to bring a vehicle into 

compliance with this Ordinance is/are not available at the time the vehicle's 

registration is due, the owner/operator may obtain a signed form to that effect 

from a manufacturer, dealer or mechanic who has verified the non-availability of 

the part(s). The owner/operator shall then take such proof to the Division. The 

Director may issue a Temporary Waiver, for a period of time and under such 

conditions as he determines, so that the vehicle may be registered if the 

Temporary Waiver is issued. The owner shall have until the expiration of the 

time period specified by the Director to complete the necessary repairs or 

replacement, and submit a Certificate of Compliance or Waiver to the Director to 

verify that the part(s) have been installed and that the vehicle is in compliance 

with all provisions of this Ordinance. The Director is under no obligation to issue 

Temporary Waivers under this section and is prohibited from issuing a Temporary 

Waiver for a vehicle that is emitting pollution levels that exceed visible emission 

requirements or that may be deemed hazardous. 

14.2 Under certain conditions as determined by the Director, the Director may issue a 

Temporary Waiver enabling a vehicle to be registered. The person to whom the 

Temporary Waiver is issued shall comply with the conditions of the Temporary 

Waiver as agreed upon by a signed affidavit. Failure to comply with the affidavit 

shall be considered a violation of this Ordinance. The Director is under no 

requirement or obligation to issue Temporary Waivers under this section and is 

prohibited from issuing a Temporary Waiver for a vehicle that is emitting 

pollution levels that exceed visible emission requirements or that may be deemed 

hazardous. 

15.0 ENGINE CHANGES 

Vehicles that have had their original engine changed, shall be tested to the Cutpoints 

applicable to the model year of the vehicle. This shall apply regardless of the year of the engine. 

If pollution control equipment that would have been installed on the original engine is missing, 

that equipment would have to be reinstalled before the vehicle would become eligible for a 

Waiver. Costs associated with such repairs shall not apply towards the Waiver amount. If the 

engine has been converted from diesel fuel to another type of fuel, the vehicle must comply with 

the laws governing the type of fuel which is being used in the vehicle. 
15.1 It is a violation of this Ordinance to register a vehicle with a diesel engine as a 

vehicle using another type of fuel or with an engine using another type of fuel as a 

diesel. 

16.0 RIGHT TO APPEAL 

Within ten (10) calendar days after the Division has given notice ofviolation(s), permit 

denial, suspension, or revocation, any person(s) aggrieved may request in writing a hearing 

before the Director. The hearing shall take place within ten (1 0) calendar days after the request 

is received. A written notice of the Director's final determination shall be given within ten (1 0) 

calendar days after adjournment of the hearing. The Director may sustain, modify, or reverse the 

action or order. The Director may negotiate a consent agreement in lieu of a permit suspension. 

16.1 Persons aggrieved by decisions of the Director may appeal to the Davis County 

Commission for a hearing. Such appeals must be made in writing and outline the 

areas where the Director has allegedly failed to administer the requirements of 

this Ordinance. The Commission then has thirty (30) days to decide whether to 

grant a hearing. If the Commission decides to grant a hearing, a hearing date 

must be provided within fifteen ( 15) days of the date of the decision to grant a 

hearing. The results of the hearing with the Commission shall be transmitted to 

the aggrieved person within ten ( 1 0) days of the closing of the hearing. 

16.2 Use of the hearing process outlined in Section 16 of this Ordinance does not 

preclude judicial review. 

17.0 PENALTY 

17.1 Pursuant to Title 26A-1-123, Utah Code Annotated, 1953, as amended and the 

statutory authority of County Commissions to enact Ordinances, any person 

violating any of the provisions of this Ordinance, either by acts of omission or 

commission, shall be guilty of a class B misdemeanor. If a person is found guilty 

of a subsequent similar violation within two years, he/she shall be guilty of a class 

A misdemeanor. 

17.2 Each occurrence and/or day a violation is committed or permitted to continue 

shall constitute a separate violation. 
17.3 At the request of the Director, the County Attorney may initiate legal action, civil 

or criminal, against any person who violates this Ordinance. 

17.4 In addition to other penalties imposed by a court of competent jurisdiction, any 

person(s) found to be in violation of this Ordinance shall be liable for all expenses 

including a reasonable attorney's fee and costs of court incurred by the Division 

and/or the County incurred in any enforcement proceeding to enforce this 

Ordinance, whether civil or criminal. 

17.5 APPENDIX E lists specific violations of this Ordinance by which permits issued 

under the provisions of this Ordinance may be suspended and for what periods of 

time and when conditions warrant, when permits may be revoked. The Director 

has authority to negotiate consent agreements in lieu of suspension time. 

17.6 The penalty schedule referenced in APPENDIX E may be amended by the Davis 

County Commission as deemed necessary to accomplish the purpose of this 

Ordinance. 

18.0 SEVERABILITY 

If any provision, clause, sentence or paragraph of this Ordinance or the application 

thereof to any person or circumstances shall be held to be invalid, such invalidity shall not effect 

the other provisions or applications of the Ordinance. The valid part of any clause, sentence or 

paragraph of the Ordinance shall be given independence from the invalid provisions or 

application and to this end the provisions of the Ordinance are hereby declared to be severable. 
19.0 EFFECTIVE DATE 

This Ordinance shall become effective the day of its enactment by the Davis County 

Commission. The appendices become effective on the specific date found on each of the 

appendices. 

Passed this 15th day ofDecember, 1994. 

Commissioner Holbrook voting aye 

Commissioner Page voting aye 

Commissioner Stevenson voting aye 

Attest: 

Margene Isom 

Davis County Clerk/ Auditor 

Approved as to form: 

Melvin Wilson 

Davis County Attorney 

Gayle Stevenson, Chairman 

Davis County Commission 
.. 

APPENDIX A 

CUTPOINTS 

Maximum Allowable Opacity Limits: 

Heavy Duty Vehicles [16,001 pounds Gross Vehicle Weight Rating (GVWR) and larger] 

70% Opacity 

Light Duty Vehicles [16,000 pounds Gross Vehicle Weight Rating (GVWR) and smaller] 

35% Opacity for Non-Turbocharged Vehicles 

30% Opacity for Turbocharged Vehicles 

Effective date: January 1, 1999 

Adopted this 23rd day of January 1, 1998 by the Davis County Commission 

Commissioner McConkie voting aye 

Commissioner Page voting aye 

Commissioner Stevenson voting aye 

Dannie R. McConkie, Chairman 

Attest: --------------------------

Margene Isom, Clerk 
· .. 

APPENDIXB 

FEE SCHEDULE 

The assessed fees for implementing the requirements of Section 6.7 of the Diesel Vehicle 

Emission Inspection/Maintenance Program shall be: 

Permitting of an Official Diesel I/M Program Fleet Station $250.00 

Annual Renewal of Station Permit 25.00 

Annual Renewal of Expired Station Permit 75.00 

Repermitting of an I/M Station at a New Location 50.00 

Clearing Mechanic Error Lockout (After 41h per Calendar Year) 15.00 

Permitting of an Official Diesel Opacity Inspector 20.00 

Annual Renewal of Inspector 10.00 

Annual Renewal of Expired Inspector 30.00 

Certificate of Compliance 4.00 

Duplicate Certificate of Compliance or Waiver 5.00 

Opacity Inspection Fee 15.00 

Opacity Reinspection Fee 10.00 

Diesel Vehicle Registration Fee 10.00 

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Passed this 15th day ofDecember, 1994. 

Commissioner Holbrook voting aye 

Commissioner Page voting aye 

Commissioner Stevenson voting aye 

Attest: 

Margene Isom 

Davis County Clerk! Auditor 

Approved as to form: 

Melvin Wilson 

Davis County Attorney 

Gayle Stevenson, Chairman 

Davis County Commission 
APPENDIX C 

Diesel Opacity Inspection 

Equipment Specifications 

Equipment Specifications to Follow Based on SAE Technical Paper Being Written On Diesel 

Opacity Sampling Equipment. 
APPENDIX D 

Diesel Vehicle Opacity 

Inspection Procedures 

Inspection Procedures To Follow Based On SAE Technical Committee Recommendations. 

( 
APPENDIXE 

PENALTY SCHEDULE 

1st 2nd 3rd 4th 

OCCURRENCE OCCURRENCE OCCURRENCE OCCURRENCE 

INACCURATE/ FORMAL UPTO 1 UPT03 REVOCATION 

INCOMPLETE WARNING MONTH MONTHS OR 

DATA (STATION & SUSPENSION SUSPENSION SUSPENSION 

MECHANIC) (STATION & {STATION & {STATION & 

MECHANIC_} MECHANIC) MECHANIC) 

PASS FAILED UPT03 UPT06 REVOCATION 

VEHICLE MONTHS MONTHS (STATION & 

SUSPENSION SUSPENSION MECHANIC) 

(STATION & (STATION & 

MECHANIC) MECHANIC) 

NON- UPT06 REVOCATION 

CERTIFIED MONTHS (STATION & 

OPACITY SUSPENSION MECHANIC) 

INSPECTOR (STATION & 

MECHANIC) 

FAILURE TO UPT06 REVOCATION 

INSPECT MONTHS (STATION) 

SUSPENSION 

(STATION) 

REVOCATION 

(MECHANIC) 

STATION SUSPENSIONS MAY BE REDUCED IN LENGTH BY A NEGOTIATED 

CONSENT AGREEMENT WHICH MAY SUBSTITUTE MONETARY PENAL TIES FOR 

PART OR ALL OF THE SUSPENSION TIME. NEGOTIATED CONSENT 

AGREEMENTS ARE ONLY APPLICABLE IN RELATION TO STATION AND 

MECHANIC PERMIT SUSPENSIONS. 

THESE PENAL TIES APPLY TO ALL PERMITS ISSUED PURSUANT TO THIS 

ORDINANCE 
Passed this 151

h day of December, 1994. 

Commissioner Holbrook Voting aye 

Commissioner Page Voting aye 

Commissioner Stevenson Voting aye 

Attest: 

Margene Isom 

Davis County Clerk/ Auditor 

Approved as to form: 

Melvin Wilson 

Davis County Attorney 

Gayle Stevenson, Chairman 

Davis County Commission 

See http://www.sae.org/servlets/productDetail?PROD TYP=STD&PROD CD=J1667 199602 - - - for Sae 11667 for further information. 
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SALT LAKE CITY-COUNTY HEALTH DEPARTMENT 

HEALTH REGULATION 

#28 

GOVERNING THE DIESEL VEHICLE EMISSIONS 

INSPECTION I MAINTENANCE PROGRAM 

Adopted by the Salt Lake City-County 

Board of Health 

September 1 , 1994 

Revised September 5, 1996 

Under Authority of Section 26A-1-121 

Utah Code Annotated, 1953, as amended 

CERTIFIED OFFICIAL COPY 

SALT LAKE CITY-COUNTY HEALTH DEPARTMENT 

By ________________ _ 

THOMAS L. SCHLENKER, M.D., M.P.H. 

Executive Director 

Attahment 2 
DIESEL VEHICLE EMISSIONS INSPECTION/MAINTENANCE PROGRAM 

SECTION 

1.0 Definitions 

2.0 Purpose 

3.0 Jurisdiction of the Department 

4.0 Powers and Duties 

5.0 Scope 

6.0 General Provisions 

7.0 Standards and Specifications for Diesel Testing Equipment 

8.0 Permit Requirements for Diesel Vehicle Emissions Inspection/Maintenance Program 

Stations 

9.0 Approval of Required Test Equipment 

10.0 Certification Requirements for Testing and Licensing of Applicants for Certified 

Diesel Opacity Inspectors. 

11.0 Inspection Procedures 

12.0 Certificates of Compliance and Waiver, Temporary Waivers 

13.0 Engine Changes 

14.0 Right to Appeal 

15.0 Penalty 

16.0 Severability 

17.0 Effective Date 

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1.0 DEFINITIONS 

For the purpose of these Regulations, the following terms, phrases, and words shall have the 

following meanings, unless otherwise defined: 

1.1 Accuracy: The degree by which an instrument is able to determine the true opacity of 

pollutants of interest; 

1.2 Calibration: The process of establishing or verifying the accuracy of an exhaust opacity 

meter to perform an accurate and consistent evaluation of engine exhaust; 

1.3 Certificate: A document, issued by the Department, to verify that a person has met the 

requirements for becoming a Certified Diesel Emissions Opacity Inspector. 

1.4 Certificate of Compliance: A document used in the Diesel Vehicle Emissions 

Inspection/Maintenance Program to certify that a vehicle meets all applicable requirements of 

the program; 

1.5 Certification: Assurance by an authorized source, whether it be a laboratory, the 

manufacturer, the State, or the Department, that a specific product or statement is, in fact, true 

and meets all requirements; 

1.6 Certified Diesel Opacity Inspector : A person who has successfully completed all 

certification requirements and has been issued a current, valid Diesel Mechanic Certificate by the 

Department; 

1.7 County: Salt Lake County, Utah; 

1.8 Department: The Salt Lake City-County Health Department or its authorized 

representatives; 

1.9 Diesel liM Program Station: A Diesel Vehicle Emissions Inspection and Maintenance 

Station that has a valid permit, issued by the Department, to operate as an official station in the 

Vehicle Emissions Inspection/ Maintenance Program; 

1.10 Diesel Vehicle Emissions Inspection/Maintenance Program: The program established, by 

the Department, pursuant to Section 41-6-163.8, Utah Code Annotated 1953, as amended; 

1.11 Director: The Director of the Salt Lake City-County Health Department or his or her 

authorized representative; 

1.12 Dynamometer: A device for simulating actual driving conditions as specified in Appendix 

B· ' 

2 
1. 13 Emissions Control Systems: Parts, assemblies or systems originally installed by the 

manufacturer in or on a vehicle for the sole or primary purpose of reducing emissions; 

1.14 Engine Exhaust Opacity Meter: An instrument that is capable of measuring the opacity of 

the smoke emanating from a motor vehicle which instrument is approved by the Department for 

this use in accordance with these Regulations as an official test instrument; 

1.15 Exemption Form: A document used to verify that a vehicle is exempt from the testing and 

repair/adjustment requirements of these Regulations; 

1.16 Fleet Diesel Inspection/Maintenance Station: Any business, organization, company, or 

entity which registers twenty five (25) or more diesel powered vehicles in Salt LakeCounty and 

has been permitted by the Department to receive such designation. 

1.17 Idle Mode: A condition where the vehicle engine is warmand running at the rate specified 

by the manufacturer's curbidle, where the engine is not propelling the vehicle, and where the 

throttle is in the closed or idle stop position. This condition must be achieved without placing 

a load on the vehicle to decrease the RPM to the specified rate; 

1.18 Inspection: A vehicle emissions test performed for the purpose of issuing a Certificate of 

Compliance or Waiver; 

1.19 Inspection Area: The area that is occupied by the analyzer, sample hose, and the vehicle 

being inspected; 

1.20 Mechanic: A Certified Emissions Mechanic possessing a current certificate, issued by the 

Department, to perform emissions testing at a location permitted by the Department; 

1.21 Motor Vehicle: A self propelled motorized vehicle with an internal combustion powered 

engine which is licensed for operation on public roads and/or streets. Motor Vehicles exempted 

from the inspection requirements of these Regulations are listed in Section 6.5 of these 

Regulations; 

1.22 Non-certified Mechanic: Any person who has not been certified by the Department to 

perform official emissions tests; 

1.23 Off-highway Vehicles: A vehicle licensed to operate exclusively offhighways; 

1.24 Opacity: The percentage of light obstructed from passing through the exhaust plume of 

a motor vehicle; 

1.25 Opacity Meter: A detection device used to measure the opacity or smoke by percentage; 

1.26 Publicly-Owned Vehicles: A motor vehicle owned by a Government entity, including but 

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not limited to the Federal Government or any agency thereof, the State of Utah or any agency 

or political subdivision thereof; 

1.27 Salt Lake City-County Board of Health: The Salt Lake City-County Board of Health as 

authorized by Section 26A-1-109, Utah Code annotated, 1953, as amended; 

1.28 Station: A Diesel liM Program Station including all station personnel, employees, and 

owner(s); 

1.29 Technical Bulletin: A document, issued to Certified Diesel Opacity Inspector and/or Diesel 

I/M Program Stations by the Department, to update, clarifY or establish policies and/or 

procedures for their implementation in the Diesel Vehicle Emissions Inspection/Maintenance 

Program; 

1.30 Temporary Waiver: A Waiver that may be issued by the Director which will allow the 

temporary registration of a vehicle based upon a vehicle owner's compliance with the conditions 

ofthe waiver; 

1.31 Training Course: A formal program, administered conducted, or approved by the 

Department, for the education of certified diesel emissions mechanics in basic emission control 

technology, inspection procedures, diagnosis and repair of emissions related problems, Diesel 

I/M Program policies, procedures, and these Regulations; 

1.32 Waiver or Certificate of Waiver: A document, issued by the Department, used to verifY 

that a vehicle has met the repair or adjustment requirements of the Diesel Vehicle Emissions 

Inspection/Maintenance Program Regulations even though specific emissions standards have not 

been met. 

2.0 PURPOSE 

It is the purpose of these Regulations to reduce PM10 air pollution levels by requiring annual 

inspections of diesel powered vehicles and by requiring emissions related repairs/adjustments for 

those vehicles that fail to meet prescribed standards so as to: 

2.1 Protect and promote the public health, safety and welfare; 

2 .2 Improve air quality; 

2.3 Comply with the Utah State Implementation Plan for PM10 and; 

2.4 Comply with the law enacted by the Legislature ofthe State ofUtah, Sections 41-6-163.8 

Utah Code Annotated, 1953, as amended. 

4 
3.0 JURISDICTION OF THE DEPARTMENT 

All aspects ofthe Diesel Vehicle Emissions Inspection/Maintenance Program within Salt Lake County 

and enumerated in Section 2.0 shall be subject to the direction and control of the Department. 

4.0 POWERS AND DUTIES 

4.1 The Department, by the Director, shall be responsible for the enforcement and administration of 

these Rules and Regulations and any other powers vested in it by law and shall: 

4.1.1 Require the submission of information, reports, plans, and specifications from Diesel 

liM Program Stations as necessary to implement the provisions, requirements, and standards 

of these Regulations; 

4.1.2 Issue permits, certifications, and charge fees as necessary to implement the provisions, 

requirements and standards of these Regulations; 

4.1.3 Perform audits of any Diesel 11M Program Station, issue orders and/or notices, hold 

hearings, and levy administrative penalties, as necessary to effect the purpose of these 

Regulations; 

4.1.4 Take samples and make analyses required to ensure that the provisions of these 

Regulations are met; and 

4.1.5 Make policies and procedures necessary to ensure that the provisions of these 

Regulations are met and that the purposes of these Regulations are accomplished. 

4.2 The Department may suspend, revoke, negotiate a fee or deny a permit of a Diesel 11M 

Program Station and/or require the surrender of the permit and unused Certificates of 

Compliance of any Diesel 11M Program Station upon showing that: 

4.2.1 A vehicle was inspected and issued a Certificate of Compliance by the station 

personnel that did not, at the time of inspection, comply with all applicable policies, 

procedures, Technical Bulletins, and these Regulations; 

4.2.2 A certified Diesel 11M Program Station allowed a Certificate of Compliance to be 

issued to a vehicle without an approved inspection being performed; 

4.2.3 The Station has violated any provisions of these Regulations, or any Rule, Regulation, 

or Department policy properly promulgated for the operation of a Diesel 11M Program 

Station; 

4.2.4 The Station was not equipped as required by Section 8.5.3 of these Regulations; 

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4.2.5 The Station was not operating from a location specified on the permit; 

4.2.6 An official inspection was performed by an individual that, at the time of the 

inspection, did not hold a valid Diesel Opacity Inspectors Certificate; and 

4.2.7 The Station denies access to a representative of the Department to conduct an 

audit/inspection or other necessary business during regular business hours. 

4.3 The Department may suspend, revoke, negotiate a fee, or deny the certificate of an official 

Diesel Opacity Inspector and require the surrender of this certificate upon showing that: 

4.3.1 The Certified Diesel Opacity Inspector caused a Certificate of Compliance to be 

issued to a vehicle without an approved inspection being performed; 

4.3 .2 The Certified Diesel Opacity Inspector denied the issuance of a Certificate of 

Compliance to a vehicle that, at the time of the inspection, complied with the law for 

issuance of said Certificate of Compliance; 

4.3.3 The Certified Diesel Opacity Inspector issued a Certificate of Compliance to a vehicle 

that, at the time of issuance, was in such condition that it did not comply with these 

Regulations; 

4.3.4 The Certified Diesel Opacity Inspector knowingly allowed a non-certified person to 

perform an official Opacity Inspection, or any portion of an official Opacity Inspection; 

4.3.5 The Certified Diesel Opacity Inspector signed an inspection form or Certificate of 

Compliance stating that he had performed the emissions inspection when, in fact, he/she did 

not; and 

4.3.6 The Certified Diesel Opacity Inspector signed a Certificate of Compliance prior to an 

inspection being performed. 

4.4 The Department shall respond, according to the policies and procedures of the Department, 

to public complaints regarding the integrity of inspections performed at Diesel liM Program 

Stations. 

5.0 SCOPE 

It shall be unlawful for any person not to comply with any policy, procedure, Technical Bulletin, or 

Regulation promulgated by the Department, unless expressly waived by these Regulations. 

6.0 GENERAL PROVISIONS 

6 
Subject to the exceptions described in Section 6.5 and pursuant to the schedule in Section 6.1 and 

6 .1.1, diesel powered motor vehicles of model years 1968 and newer that are or will be registered or 

principly operated in Salt Lake County shall be subject to an exhaust opacity inspection performed 

by a Diesel liM Program Station, a Department operated test facility or other entity approved by the 

Director. 

6.1 Program Beginning Date: Testing of diesel powered vehicles shall begin on November 1, 

1994. Beginning Jan 1, 1995, a Certificate of Compliance or Waiver, or evidence that the motor 

vehicle is exempt from the Diesel liM Program requirements (as defined in Section 6.5 ofthese 

regulations) shall be presented to the County Assessor or the Utah State Tax Commission and 

the Air Pollution Control Fee paid as conditions precedent to annual registration or annual 

renewal of registration of a motor vehicle. 

6.1.1 The beginning date noted in 6.1 may be temporarily postponed if it is deemed 

necessary by the Director to aid in the smooth and effective implementation of the Diesel 

Vehicle Inspection Maintenance Program. The temporary postponement of the program 

beginning date would only be implemented if it is determined by the Director that the 

integrity of the program may be jeopardized because testing equipment, procedures, 

facilities, software or other aspects of the program are not ready for effective and accurate 

testing to begin. Different start-up dates may be selected for light and heavy duty diesels. 

6.2 Certificate Validity Period: The official Diesel Opacity Inspection shall occur and a 

Certificate of Compliance or Waiver shall be issued within eleven ( 11) months prior to the date 

of the motor vehicle registration. 

6.3 Dealer Certificates: A Certificate of Compliance issued to a dealer licensed with the State 

of Utah and issued in the dealer's name, shall be valid for registration purposes for a period of 

six months as specified in Section 41-3-28.5, Utah Code Annotated, 1953, as amended. The 

purchaser's name, address, and phone number shall be recorded by the dealer on the back of the 

Certificate of Compliance. 

6.4 Publicly-Owned Vehicles: Owners of publicly-owned vehicles shall comply with the Diesel 

liM Program requirements pursuant to a schedule determined by the Department. Federallyowned vehicles and vehicles of employees operated on a federal installation that do not require 

registration in the State ofUtah shall comply with the Diesel liM Program requirements pursuant 

to a schedule determined by the Department. 

6.5 Vehicle Exemption. The following vehicles are exempt from these Diesel liM Program 

requirements: 

6.5.1 Any vehicle of model year 1967 or older; 

6.5.2 All agricultural implements ofhusbandry and any motor vehicle that qualifies for an 

exemption as required by Section 41-6-163.6 Utah Code Annotated, 1953, as amended; 

7 

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6.5.3 Any vehicle used for maintenance or construction and not designed or licensed to 

operate on the highway; and 

6.5.4 Any new vehicle being sold for the first time that has a valid MSO (manufacturers 

statement of origin) form. 

6.5.5 Any diesel powered vehicle of the current or future model year or of the two (2) 

model years immediately proceeding the current model year, providing each ofthe following 

requirements are met: 

(a) the Gross Vehicle Weight Rating (GVWR) of the vehicle is at least twenty six 

thousand pounds; 

(b) the vehicle is registered with the International Registration Plan (IRP) and the 

International Fuel Tax Agreement (IFT A); 

(c) the vehicle travels less than fifty percent (50%) of its total annual vehicle miles 

within the State of Utah. Annual vehicle miles and percentages shall be calculated on 

a per vehicle basis using actual mileage from the prior year. The percentage of in state 

mileage on new vehicles shall be estimated based on mileage from a replaced or other 

similarly situated vehicle. 

(d) the vehicle owner submits a completed, signed Diesel Emissions Exemption 

Affidavit at the time of vehicle registration. 

6.5 .6 The Department may request, prior to the granting of an exemption or any time during 

the exemption period, various records such as apportionment, mileage (IRP, IFTA), and 

registration records documenting a vehicles actual age, weight, and Utah/total mileage. 

6.5. 7 Failure to provide the Department with requested documents is grounds for denial of 

exemption privileges. Discovery by the Department of incorrect application information 

may result in, in addition to the penalties described in section 15.0 of this regulation, the 

permanent denial of exemption privileges for all vehicles registered to that person, owner, 

corporation or entity. 

6.6 Equipment Available for Inspection. Required tools and equipment as noted in Section 8.5.3 

supplies, records, unused Certificates of Compliance, and other required forms, records of 

completed inspections, and duplicate copies of Certificates of Compliance issued shall be kept 

at the Official Diesel I/M Program Station at all times for a period of not less than eighteen 

months and shall be available for inspection and collection by the Department at any time the 

inspection station is open for business. 

6.6.1 A periodic inspection and audit shall be made by a Department representative to 

8 
verifY compliance with these of the periodic inspection and audit of the Diesel liM Program 

Station, the Department representative shall, as applicable, observe the performance of an 

electronic equipment calibration performed by the Certified Diesel Opacity Inspector, 

examine calibration records, and Certificates of Compliance, as well as other required 

reports, forms, or records to see that the use of these items is in compliance with these 

Regulations and the policies and procedures of the Department. 

6.6.2 During the time of the inspection and audit by the Department, the Department 

representative shall have exclusive access to the approved emissions testing equipment. 

6.6.3 The Department representative may check the accuracy of the test equipment using 

Department audit procedures to verifY that the equipment is reading within the tolerances 

established by the Department. Test equipment not reading within the tolerances shall be 

re-calibrated to acceptable tolerances or be placed "out of service". 

6.7 Fees. The fees assessed upon Diesel liM Program Stations and the Certified Diesel Opacity 

Inspectors shall be determined according to the fee schedule adopted by the Department. The 

fee schedule is referenced in Appendix A to these regulations and may be amended by the Salt 

Lake City-County Board of Health as the Board deems necessary to accomplish the purpose of 

these Regulations. 

6.7.1 Air Pollution Control Fee-- one dollar ($1.00). This fee assessment includes all 

motorized vehicles including those that are exempted from the inspection requirements of 

these regulations. 

6.7.2 Diesel I/M Program Stations may charge fees for required services. Those fees may 

not exceed, for each vehicle inspected, the following amounts: 

(a). The Diesel emissions inspection fee shall not exceed the amount noted in Appendix 

A. If a vehicle fails the inspection, the owner is entitled to one free re-inspection if 

he/she returns to the Station that performed the original test within thirty (30) days 

from the date of the initial inspection. The Station shall extend the thirty day reinspection time to accommodate the vehicle owner, if the station is unable to schedule 

the re-test of the vehicle within the thirty-day time period. 

(b). Duplicate Certificates of Compliance may be issued to a vehicle owner/operator 

within two months of the initial test. The fee may not exceed the amount in Appendix 

A. 

(c). Fees are subject to change and may be amended by the Salt Lake City-County 

Board of Health as the board deems necessary to accomplish the purpose of these 

Regulations. 

(d). If a vehicle fails the emissions test and is within the time and mileage requirements 

9 

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of the federal emissions warranty contained in the Federal Clean Air Act, the inspector 

shall inform the owner/operator that he/she may qualify for warranty coverage of 

emission related repairs as provided by the vehicle manufacturer and mandated by the 

Federal Environmental Protection Agency. 

6.7.3 Diesel Emission Exemption Fee. Any vehicle which qualifies for an exemption from 

testing requirements under 6.5.5 of these Regulations shall be required to remit an 

exemption fee upon application for registration of the vehicle. This fee shall be in the 

amount listed in Appendix A of this regulation. 

6.8 Vehicle Idling Limitation. No owner or operator of a diesel powered vehicle shall allow or 

permit such vehicle to remain in an idling mode or condition for a period of time exceeding 

fifteen ( 15) minutes. 

6.8.1 Exemption to Idling Limitations. Vehicles may be exempted from the idling limitation 

requirements of Section 6.8 under the following conditions: 

(a). To supply power to a refrigeration unit for the purpose of cooling the contents of 

a trailer. 

(b). To provide heat or air conditioning to a sleeper unit of the vehicle. 

(c). Emergency vehicles. 

6.8.2 Vehicles exempted from the Vehicle Idling Limitations as applicable under section 

6.8.1 (a) and (b) of these regulations shall not remain in an idling condition for a period 

longer than fifteen (15) minutes if located within five hundred (500) feet of any residence. 

7.0 STANDARDS AND SPECIFICATIONS FOR DIESEL TESTING EQUIPMENT 

7.1 No diesel emissions inspection required by these Regulations shall be performed unless the 

type of instrument used for measuring exhaust opacity from diesel powered motor vehicles is 

contained in the list of approved test equipment as provided by the Department. The test 

equipment shall meet the requirements of the equipment specifications referenced in Appendix 

C of these Regulations. The instrument shall be in good working condition, capable of meeting 

calibration requirements of the Department, and operated according to manufacturer's 

specifications and operating procedures. 

7.2 Any test equipment used by a Diesel liM Program Station shall be registered with and 

approved by the Department and, if required, shall bear a registration sticker issued by the 

Department. Registration stickers are not transferable or assignable. Any new or used test 

equipment put in use after station approval must be approved by the Department before use. 

Test equipment used temporarily during times of breakdown or repair of the registered 

equipment do not require a registration sticker, but shall meet all other requirements of this 

section including the approval of the Department before use. 

10 
7.3 The test equipment printers shall be maintained in such a manner that the printing of the test 

results shall be clearly visible on all copies. If any printer fails to properly function, then the 

station shall discontinue testing until the required repairs have been performed. 

7.4 It shall be illegal for any person to modify the hardware or the software of an approved 

opacity meter without written application and written approval by the Department. 

7.5 Documentation, Logistics, and Warranty Requirements 

7. 5.1 Instruction Manual: An instruction manual shall accompany each exhaust opacity 

meter and shall contain at least the following information for the analyzer: 

(a) A complete technical description; 

(b) The functional mechanical and electrical schematics; 

(c) The accessories and options that are included and/or available; 

(d) The model number, identification marking and location; 

(e) Operating maintenance including daily, weekly, and monthly accommodations for 

maintaining sample system integrity including, but not limited to, leaks, hang-up, 

calibration and filters. The services to be performed only by the manufacturer shall be 

clearly identified; 

(f) Information concerning the nearest service facility where the equipment can be 

serviced; 

(g) The warranty provisions for the opacity meter, including a list of warranty repair 

stations by name, address, and telephone number; and 

(h) The opacity meter shall be maintained in accordance with the manufacturer's 

recommended maintenance schedule and records of this maintenance service shall be 

maintained for examination by the Department. 

7.6 Calibration of Exhaust Opacity Meters. 

7 .6.1 A certified Diesel Opacity Inspector shall perform a mechanical/electrical equipment 

calibration following manufacturer's recommended procedures within three (3) days prior 

to an Official Diesel Opacity Inspection. The calibration shall be performed with a known 

source oflaboratory certified light absorbing material such as a neutral density filter or other 

device approved by the Department. 

7 .6.2 A certified Diesel Opacity Inspector shall perform an electrical zero and span check 

following the opacity meter manufacturer's procedures prior to an Official Diesel Opacity 

Inspection. An opacity meter that fails the zero and span check shall be cleaned or recalibrated following manufacturer's recommendations. 

7 .6.3 If the opacity meter requires repairs in order to be used in accordance with these 

Regulations, the certified station shall notify the Department that the opacity meter is "Out 

of Service" and shall again notify the Department after repairs are made and before testing 

11 

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is resumed. 

7.6.4 The opacity meter instruction manual and other Department approved information 

shall be reviewed by the inspector to ensure that proper procedures are being used for 

performing the calibration check. 

8.0 PERMIT REQUIREMENTS OF THE DIESEL VEHICLE 

INSPECTION/MAINTENANCE PROGRAM STATION 

8.1 Owners of vehicle fleets may apply to the Director for a Diesel liM Program Station 

inspection permit. This permit allows fleet owners to inspect only their own vehicles that are 

registered to the same individual or corporation. 

8.1.1 A "fleet" shall consist of a minimum twenty five(25) diesel powered vehicles or a 

number specified by the Director. 

8.1.2 All fleet stations and mechanics certified to perform Diesel I/M tests will be subject 

to regular and unannounced inspections by the department. 

8 .1.3 During self-certifying fleet audits, auditors will review vehicle emissions inspection 

and maintenance records and may inspect a representative sample of vehicles with an opacity 

meter to verify compliance. 

8 .1.4 Self-certifying fleet vehicles may be subject to a snap idle test with visual evaluation 

of smoke opacity. Vehicles that appear to exceed the opacity limit may be re-measured with 

an opacity meter and repaired if the meter confirms that the exhaust opacity exceeds the 

standard. 

8 .1.5 Self-certifying stations shall maintain records of specific repairs performed to bring 

failed vehicles into compliance. 

8.2 The Director is authorized to issue or deny permits for the opacity inspection of diesel 

powered vehicles and the issuance of Certificates of Compliance or Waivers. 

8.3 No permit for any Official Diesel liM Program Station may be assigned, transferred, or used 

by any person other than the original owner identified on the permit application for that specific 

Diesel liM Program Station. The permit shall be posted in a conspicuous place within public 

view on the premises. 

8.4 The station shall be a permanent location which meets all applicable zoning requirements to 

provide for the inspection of diesel vehicles, as licensed, and as defined in these Regulations. 

8.5 Application for a Diesel liM Program Station Permit shall be made to the Department upon 

12 
a form provided by the Director. No permit shall be issued unless the Director or his 

representative finds that the facilities, tools and equipment of the applicant comply with the 

requirements of these Regulations and that competent personnel, certified under the provisions 

of Section 10.0 are employed and will be available to make inspections and adjustments, and the 

operation thereof will be properly conducted in accordance with these Regulations. 

8.5.1 A Diesel liM Program Station shall notify the Department and immediately surrender 

all unused Certificates of Compliance if the station does not have a Certified Diesel Opacity 

Inspector employed; 

8.5.2 A Diesel liM Program Station shall comply with all terms stated in the permit 

application and all the requirements of these Regulations; and 

8.5.3 As a condition for permitting all Diesel liM Program Stations, the following tools 

shall be available for performance of the inspection and maintenance of diesel powered 

motor vehicles: 

(a) A Department approved exhaust opacity meter that meets the mtmmum 

specifications as outlined in Appendix C of these Regulations; 

(b) A Department approved dynamometer (if testing light duty diesel vehicles) that 

meets the minimum specifications as outlined in Appendix B of these Regulations; 

i. Facilities which are fleet certified only and which will not be testing light duty 

vehicles are exempted from the dynamometer requirement of 8.5.3.(b). 

(c) A Department approved personal computer capable of meeting the minimum 

specifications as outlined in Appendix C of these Regulations; 

(d) A handbook, approved by the Department, that includes testing procedures to be 

followed by the Certified Diesel Opacity Inspector; 

(e) An accurate strip chart recorder or other recording device, approved by the 

Department and capable of recording diesel test data, to be analyzed at a later date; 

(f) Reference manuals approved by the Department that contain tune up specifications, 

and information covering the emissions control systems for the model years and makes 

of vehicles involved in the Diesel Vehicle Emissions Inspection/Maintenance Program; 

(g) Sufficient hand tools for proper performance of inspection and maintenance of the 

vehicle; 

(h) Vehicle exhaust removal equipment; 

13 

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(i) The Test Equipment manufacturer's maintenance and calibration manual which must 

remain in the inspection area; and 

U) All forms, Technical Bulletins, and other information materials provided by the 

Department. 

8.5.4 All facets of the official Diesel liM Program shall be performed by the Certified Diesel 

Opacity Inspector including: 

8.5.4.1 Opacity inspection equipment preparation, and calibration checks; 

8.5.4.2 Dynamometer operation, maintenance and calibration; 

8.5.4.3 Exhaust opacity sampling and analysis for the purpose of an official emissions 

test for issuance of a Certificate of Compliance; and 

8.5.4.4 Preparation of reports, forms, Certificates of Compliance, the tampering 

inspection, inserting or attaching the exhaust opacity sampling equipment, hooking up 

the tachometer, entering the data, preconditioning the vehicle, and signing Certificates 

of Compliance and inspection forms. 

8.5 .5 An Official Diesel I/M Program Station shall be kept in good repair and in safe 

condition for inspection purposes free of obstructions and hazards. 

8.6 Permit Duration and Renewal 

8.6.1 The permit for a Diesel liM Program Station shall be issued annually and shall expire 

one year from date of issuance. The permit shall be renewable sixty (60) days prior to the 

date of expiration; 

8.6.2 It is the responsibility ofthe owner/operator of the inspection station to pursue the 

permit renewal through appropriate channels. 

8.6.3 Diesel I/M Program Station to hold Department Harmless 

In making application for a permit or for its renewal, such action shall constitute a 

declaration by the applicant that the Department shall be held harmless from liability 

incurred due to action or inaction of Diesel liM Program Station's owners or their 

employees. 

9.0 APPROVAL OF REQUIRED TEST EQUIPMENT 

9.1 Diesel Opacity Inspections required by these Regulations shall not be performed unless the 

14 
equipment used meets the specifications as defined in this Regulation and as approved by the 

Department. 

9.2 Any changes to the design or performance characteristics of component specifications which 

may affect the equipment or instrument performance shall be approved by the Department. It 

shall be the instrument manufacturer's responsibility to confirm that such changes have no 

detrimental effect on the opacity meter or other equipment or instrument performance. 

10.0 CERTIFICATION REQUIREMENTS FOR TESTING AND LICENSING OF 

APPLICANTS FOR CERTIFIED DIESEL OPACITY INSPECTORS 

10.1 No person shall perform any part of an official Diesel Opacity Inspection for the issuance 

of a Certificate of Compliance or Waiver unless the person possesses a valid Diesel Opacity 

Inspector's Certificate issued by the Department. 

10.2 Applications for an official Diesel Opacity Inspector shall be made on a form to be 

prescribed by the Department. No certificate shall be issued unless the applicant complies with 

the requirements of this section. 

(a) An applicant shall demonstrate knowledge, skill, and competence concerning the 

operation and theory of diesel-fueled internal combustion engines; 

(b) An applicant shall complete a Department approved training course and shall 

demonstrate knowledge, skill, and competence by passing a written and performance 

qualification test including, but not limited to, knowledge of the following: 

i. Knowledge of the Rules and Regulations of Diesel Opacity Inspection Program 

procedures; 

ii. Operation of and proper use, care, maintenance, and calibration of the Department 

approved Diesel liM Program Test Equipment; 

iii. Proper use and distribution of the required inspection forms, Certificates of 

Compliance, calibration records, and supplemental documents; and 

iv. Waiver requirements for all diesel vehicles failing the initial emissions inspection. 

(c) Re-qualification requirements for Diesel Opacity Inspectors 

i. Upon determination by the Director of the necessity of updating the qualifications 

for diesel opacity inspectors, they shall be required to re-qualify. Re-qualification 

requirements shall be determined by the Director; 

ii. Diesel Emissions Opacity Inspectors shall be required tore-qualify annually. Failure 

15 
to re-qualify within the required period of time shall result in the suspension or 

revocation of the Diesel Opacity Inspector's permit as described in these Regulations. 

(d) The Diesel Opacity Inspector's Certificate shall be valid only at the station where the 

inspector is currently employed at the time the certificate is issued. If the inspector is later 

employed at another station, the inspector shall notify the Department of the employment 

change. The inspector shall re-apply for a certificate and pay the required fees. Prior to 

testing at the new station, the inspector shall be certified there and a new certificate number 

shall be issued. This certificate shall expire on the same date as the original. 

10.3 Certificate Expiration 

10.3 .1 The opacity Inspector's Certificate shall be issued annually and shall expire one year 

from the date of issuance. The certificate shall be renewable sixty days prior to the date of 

expiration. 

1 0.3.2 It is the responsibility of the inspector to pursue the renewal of the Opacity 

Inspector's Certificate. 

11.0 INSPECTION PROCEDURE 

11.1 The Official Opacity Inspection shall be performed by Certified Diesel Opacity Inspectors 

who have been certified at the station where the inspection is being performed and in accordance 

with Department approved inspection procedures. 

11.2 The entire inspection shall take place within the reach of the opacity inspection equipment 

hoses and/or electrical leads. 

11.3 The temperature of the inspection area shall be between 41 degrees Fahrenheit and 110 

degrees Fahrenheit during the inspection. 

11.4 The opacity inspection equipment shall be kept in an area that provides adequate protection 

from the weather, wind, and temperature extremes. 

11.5 The electrical supply to the opacity inspection equipment shall be able to meet the 

equipment manufacturer's requirements for voltage and frequency stability. 

11.6 The Diesel Opacity Inspector shall not inspect or test any motor vehicle with a mechanical 

condition which may cause injury to inspection personnel or damage to the inspection station or 

test equipment or which may affect the validity of the test, until such condition is corrected. 

Such conditions include, but are not limited to: coolant, oil, or fuel leaks, low oil or low fluid 

levels. 

11.7 Any time an engine stalls during an official Diesel Opacity Inspection, the test shall be re16 
started. If an inspector cannot complete a test because of continuous stalling, fluctuating RPM 

measurements, or RPM measurements that are not within the Department specified parameters, 

then these problems shall be corrected before the test is continued. 

11.8 The Diesel Opacity Inspector shall accurately identify and enter vehicle and owner 

information from the vehicle to be tested as required by the data entry process. 

11.9 For vehicles with multiple exhaust outlets, the Opacity Inspector shall observe the outlets 

during the pre-conditioning or clean-out cycle to determine which outlet emits the heavier 

exhaust smoke. During testing, the sample shall be taken from the exhaust outlet which emits 

the heavier smoke, if there is a difference in smoke levels. 

11.10 The Diesel Opacity Inspector shall determine the appropriate test procedure to follow 

depending on vehicle type and proceed with the test procedures as recommended by EPA and 

the Society of Automotive Engineers (SAE) and outlined in Appendix D and E of these 

Regulations. 

12.0 CERTIFICATES OF COMPLIANCE AND WAIVER, TEMPORARY WAIVERS 

CERTIFICATES OF COMPLIANCE 

12.1 No person shall make, issue or knowingly use any photo copy, imitation or counterfeit of 

an official Certificate of Compliance or Waiver; 

12.2 No person shall knowingly use a stolen or counterfeit Certificate of Compliance or Waiver; 

12.3 Certificates of Compliance shall be purchased only from the Department; and 

12.4 No refund or credit shall be allowed for unused Certificates of Compliance, except as 

provided in Section 12.1 0. 

12.5 Purchase of Certificates of Compliance 

12.5.1 Certificates of Compliance shall only be sold to a representative ofthe Diesel liM 

Program Station possessing an acceptable form of identification; 

12.5.2 Certificates of Compliance shall be sold at a cost adopted by the County Board of 

Health and referenced in Appendix A, in lots to be determined by the Department. The 

Department may limit the number of Certificates of Compliance purchased to a number that 

the Department believes can be secured and stored safely; and 

12.5.3 Certificates of Compliance shall not be sold, loaned, transferred, or given to any 

other Diesel liM Program Station, or any unauthorized individual. The Diesel I/M Program 

17 
' ' . 

Station shall at all times account for all Certificates of Compliance that have been purchased 

by the station. 

12.6 Certificates of Compliance shall not be issued until an inspection has been performed as 

required by these regulations. 

12.7 All unused Certificates of Compliance shall be kept in a secure place at all times to prevent 

loss or theft. 

12.8 Certificates of Compliance shall be used in sequential order by Diesel liM Program 

Stations. 

12.9 Certificates of Compliance that are missing, stolen or unaccounted for, shall be reported 

to the Department within 24 hours and the station shall cease performing emissions tests until 

an investigation by the Department has been completed and the Department re-authorizes the 

station to again begin testing. 

12.10 Upon final cancellation, suspension or revocation of the Diesel liM Program Permit of 

any station, the station owner, manager or other responsible person shall immediately surrender 

all unused Certificates of Compliance to the Department. The Department shall receipt and 

refund the fee paid for unused Certificates of Compliance to the station owner according to the 

Salt Lake County Auditor's procedures. Upon transfer or termination ofbusiness ownership, the 

station permit and all Certificates of Compliance shall be immediately forwarded to the 

Department. Any person acquiring a business that has been permitted as an official Diesel liM 

Program Station is prohibited from using any permit or Certificates of Compliance issued to the 

former business. 

Certificates of Waiver 

12.11 A Certificate ofWaiver may be issued, by the Department, for light duty diesel vehicles 

if all of the following requirements are met: 

12.11.1 All air pollution control devices required by these Regulations are in place and 

apparently operable on the vehicle. If the devices have been removed or rendered 

inoperable, they shall be replaced or repaired before a Waiver is granted. Costs for repairs 

or replacement of pollution control equipment shall not count towards the repair Waiver; 

and 

12.11.2 The vehicle continues to exceed applicable opacity standards after $750 (seven 

hundred fifty dollars) of acceptable emissions related repairs have been performed after the 

first official test failure. Proof of repair costs shall be provided for the vehicle to the 

Department in the form of a dated, itemized bill, invoice work order, manifest or statement 

18 
in which emissions related parts are specifically identified. If repairs are made by the vehicle 

owner or by someone who does not possess a valid business license for automobile or truck 

repair, then the cost oflabor shall not be included in the $750. 

12.12 A Waiver may be issued, by the Department, for heavy duty diesel vehicles if all of the 

following requirements are met: 

12.12.1 Air pollution control devices are in place and apparently operable on the vehicle. 

If the devices have been removed or rendered inoperable, they shall be replaced or repaired 

before a Waiver is granted. Costs for repairs or replacement of pollution control equipment 

shall not count towards the repair Waiver; and 

12.12.2 The vehicle continues to exceed applicable opacity standards after $1500 (fifteen 

hundred dollars) of acceptable emissions related repairs have been performed after the first 

official test failure. Proof of repair costs shall be provided for the vehicle to the Department 

in the form of a dated, itemized bill, invoice, work order, manifest or statement in which 

emissions related parts are specifically identified. If repairs are made by the vehicle owner 

or by someone who does not possess a valid business license for automobile or truck repair, 

then the cost oflabor shall not be included in the $1500. 

12.13 Any vehicle that experiences any increase in opacity levels since the first opacity 

inspection shall not be eligible for an emissions repair waiver regardless of the amount spent in 

attempting to repair the vehicle. 

12.14 Waivers shall only be issued by the Department unless the Department determines other 

acceptable methods of issuing the waivers. A waiver shall only be issued after determining that 

the vehicle complies with the requirements of this Section for Waiver issuance. 

Temporary Waivers 

12.15 For all vehicles, if a part or parts are necessary to bring a vehicle into compliance is/are 

not available by the time the vehicle's registration is due, the owner/operator may obtain a signed 

form to that effect from a manufacturer, dealer, or mechanic who has verified the non-availability 

of the part(s). The owner/operator shall then take such proof to the Department. The Director 

may issue a Temporary Waiver, for a period of time and under such conditions as he has 

determined, so that the vehicle may be registered. The owner shall have until the expiration of 

the time period specified by the Director to complete the necessary repairs or replacement, and 

submit a Certificate of Compliance to the Director to verify that the parts(s) have been installed 

and that the vehicle is in compliance with all provisions of these Regulations. The Director is 

under no obligation to issue these Waivers. 

12.16 Under certain conditions as determined by the Director, the Director may issue a 

19 

•. 

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Temporary Waiver enabling a vehicle to be registered. The person to whom the Temporary 

Waiver is issued shall comply with the conditions of the Temporary Waiver as agreed upon by 

a signed affidavit. Failure to comply with the affidavit shall be considered a violation of these 

Regulations. The Director is under no requirement or obligation to issue these Waivers. 

13.0 ENGINE CHANGES 

Vehicles, in which the original engine has been changed, must meet the same standards as was 

applicable on the originally manufactured vehicle. If the engine has been converted from diesel 

fuel to another type of fuel, the vehicle must comply with the regulations governing the type of 

fuel which is being used in the vehicle. 

14.0 RIGHT TO APPEAL 

Within 10 calendar days after the Department has given a notice ofviolation(s), permit denial, 

revocation, or suspension, any person(s) aggrieved may request in writing a hearing before the 

Department. The written request for hearing shall be made on a form provided by the 

Department. The hearing shall take place within I 0 calendar days after the request is received. 

A written notice of the Director's final determination shall be given within 10 calendar days after 

adjournment of the hearing. The Director may sustain, modify, or reverse the action or order. 

15.0 PENALTY 

15.1 Any person who is found guilty of violating any of the provisions of these Rules and 

Regulations, either by failing to do those acts required herein or by doing a prohibited act, shall 

be guilty of a class B misdemeanor pursuant to Section 26A-1-123, Utah Code Annotated, 1953, 

as amended. If a person is found guilty of a subsequent similar violation within two years, he 

shall be guilty of a class A misdemeanor pursuant to Section 26A-1-123, Utah Code Annotated, 

1953, as amended; 

15.2 Each time a violation is committed, or permitted to continue, shall constitute a separate 

offense; 

15.3 The County Attorney, or, if appropriate, the City Attorney may initiate legal action, civil 

or criminal, requested by the Department to abate any condition that exists in violation of these 

Rules and Regulations; 

15.4 In addition to other penalties imposed by a court of competent jurisdictions, any person( s) 

found guilty of violating any of these Rules and Regulations shall be liable for all expenses 

incurred by the Department; and 

15.5 The Penalty Schedule referenced in Appendix F may be amended by the Department as the 

20 
Department deems necessary to accomplish the purpose of these Regulations. 

16.0 SEVERABILITY 

If any provision, clause, sentence, or paragraph of these Regulations or the application thereof 

to any person or circumstances shall be held to be invalid, such invalidity shall not affect the 

other provisions or applications of these Regulations. The valid part of any clause, sentence, or 

paragraph of these Regulations shall be given independence from the invalid provisions or 

application and to this end the provisions of these Regulations are hereby declared to be 

severable. 

17.0 EFFECTIVE DATE 

These Regulations shall become effective the day of their enactment by the Salt Lake City-County 

Board of Health. The appendices become effective on the specific date found on each of the 

appendices. 

21 

I • • 
APPENDIX SCHEDULE 

Appendix A Fee Schedule 

Appendix B Dynamometer Requirements 

Appendix C Equipment Specifications 

Appendix D LDDV Testing Procedure 

Appendix E HDDV Testing Procedure 

Appendix F Penalty Schedule 

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APPENDIX A 

FEE SCHEDULE - EFFECTIVE SEPTEMBER 18, 1996 

The assessed fees for implementing the requirements of Section 6.7. of the Diesel Vehicle Emissions 

Inspection/Maintenance Program by the Department shall be: 

Permitting of a Diesel liM Program Station 

Annual Renewal of Station Permit 

Annual Renewal of Expired Station Permit 

Re-permitting a Diesel liM Station at a 

New Location 

Permitting an Official Diesel liM Mechanic 

Annual Renewal of Diesel Mechanic Permit 

Annual Renewal of Expired Diesel Mechanic 

Permit 

Diesel Emissions Certificate of Compliance 

Diesel Emission Exemption Fee 

Air Pollution Control Fee 

$ 

Fees that may be charged by Official Diesel liM Program Stations: 

Official Diesel Opacity Inspection 

Duplicate Diesel Certificates of Compliance 

23 

250.00 

25.00 

75.00 

50.00 

20.00 

10.00 

30.00 

4.00 

9.00 

1.00 

23.00 

5.00 
MD-250 

Horsepower: 

Loading: 

Controls: 

Hand Control: 

Rolls: 

Maximum Speed: 

Frame: 

Lift: 

Air Requirements: 

Power Requirements: 

Inertia: 

Axle Weight: 

Shipping Weight: 

Options: 

APPENDIXB 

Diesel Dynamometer Specifications 

CHASSIS DYNAMOMETER 

900 hp maximum measurement capability 

605 hp peak absorption 

Air-cooled eddy current power absorber (MDK-250) 

Pentium-based PC control system 

MD-7000 Control Platform 

Hand-held infrared controller for remote operation 

Precision machined & dynamically balanced 

Belted for bi-directional capability 

I 0. 70" (272 mm) diameter balanced rolls 

40" (1,016 mm) face length 

28" (711 mm) inner track width 

108" (2743 mm) outer track width 

19.6" (498 mm) roll spacing 

150 mph (242 kph) Intermittent 

110 mph (177 kph) Continuous 

Heavy-duty structural steel frame 

Heavy-duty restraint kit included 

Between roll lift with integrated roll lock 

80 PSI, dry, regulated, oil free 

115 V AC single phase, 60 Hz, 15 Amps (computer) 

230 V AC single phase, 60 Hz, 40 Amps ( dyno controls) 

Approx. 2,000 lbs 

12,000 lbs (5,455 kg) maximum 

9,400 lbs (4,264 kg) 

• Color printer • 22,000 lb axle weight 

• Above ground ramps • Monitor upgrade 

• Cooling fan • Roll covers 
• 4 & 5 Gas analyzers • Overseas crating 

• 230 V AC control system • 50 Hz system 

HEAVY DUTY DYNE SPECS FOR LIGHT DUTY DIESEL TESTING 

Power and Air Service Considerations: 

• A dedicated 110 V AC single-phase 20-ampere circuit for the analyzer cabinet. 

• A dedicated 220 VAC single-phase 30-ampere circuit for the dynamometer. 

• A dedicated voice grade telephone service for each analyzer cabinet to 

communicate to the host computer. 

• An 80- 120 psi, dry compressed air supply to operate the dynamometer lift. 

• In ground systems must have adequate pit drainage and ventilation systems. 

See foundations detail for requirements. 

• The addition of a system to insure the building is adequately ventilated due to 

the introduction of substantially higher quantities of vehicle exhaust into the 

work area as a result of the ASM test. 

• The installation of a Carbon Monoxide Monitoring System to provide 

adequate warning to the station's employees if an unsafe level of carbon 

monoxide is reached. 

• The installation of tie downs will provide greater stability during testing as 

well as safety for employees and customers. 

Data Communications Considerations 

Each analyzer will require one, standard telephone line with a modular (RJ11) phone jack for use only by ASM2 testing system. You will need a 

separate telephone line and jack for each system installed. 

Equipment Specification and Other Information 

Analyzer Cabinet 

The analyzer comes with a 25-foot power cord for the 110 VAC supply. A 25-

foot probe hose and probe are also included. 

Dimensions 

Height 

Width 

Depth 

Electrical Power 

Line Voltage 

Current Load 

72" 

41" 

25" 

110 V AC, single phase 

20 Ampere 
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Telephone Line 

A dedicated telephone line (voice grade, two-wire circuit, terminated to the 

analyzer cabinet with a RJ-11 modular phone jack) must be installed for each 

analyzer to provide communications between the analyzer and a host computer. 

This line must be of sufficient length to allow for the cabinet to be positioned 

properly to view the monitor during an ASM test. A 20-foot telephone line 

extension is provided with the analyzer cabinet. 

Heavv Duty Dynamometer (Below ground installations only) 

Dimensions 

Height 

Width 

Length 

Electrical Power 

Line Voltage 

Line Current 

Weight Capacity 

16,000 lbs. GVWR 

Dynamometer Control Box 

15 inches 

152 Yz inches 

36 Yz inches 

220 V AC, single phase 

30 Ampere 

The dynamometer control box is an interface unit that converts signal voltages 

from the analyzer cabinet into high voltages to the dynamometer motor. 

Mounting Configurations 

This unit can physically mounted in three possible locations: (1) on a wall 

adjacent to the dynamometer, (2) on a frame anchored to the floor near the 

dynamometer and (3) mounted to the dynamometer motor housing cover. See 

detail drawings. 

All wiring (both signal and high voltage) should be installed in conduit between 

the dynamometer and the dynamometer controller. Local building codes will 

dictate specific requirements for the size and material of the conduit. 

Power Disconnect Box 

There must be a fused 30 amp Safety Switch box installed between the building 

main circuit breaker panel and the dynamometer control box. This switch should 

be mounted on the dynamometer control box or in the wall as near as possible to 

the dynamometer control box. Local building codes will dictate specific 

requirements. This safety switch box is the positives disconnect device, which 

must interrupt power to the dynamometer controller during troubleshooting or 
servtcmg. Site preparation must include enough cable to bring 220 V AC from the 

disconnect box to the dynamometer controller plus an additional five (5) feet. 

'• 
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APENDIXC 

Opacity Meter Specifications 

The following data comprises the performance characteristics of the RRT 100: 

Measurement Specifications 

Method Range Resolution 

Visual opacity 0-100% 0.1% 

Absorption Coefficient 0-30.0 Vm 

Kin 1/m (density) 

0.01 lim 

Mass concentration 

In mg/m3 

1 0-1966 mg/m3 1 mg/ m

3 

Physical Specifications 

Power requirements: 11-15 volts 

Data ports: 

Dimensions: 

Weight: 

Air pump volume 

17 amps continuous 

2 serial RS 232 C 

17 .5" wide x 16" deep x 

1 0.5'' high 

50 lbs. 

1.2 liters/sec. 
EQUIPMENT SPECIFICATIONS 

Equipment used for testing in the Diesel Inspection and Maintenance Program will be only those 

approved by the Department and included on the official Department list of approved equipment. 

Equipment must meet those specifications as outlined in Specifications for the Diesel Inspection 

and Maintenance Program or as designated by the Director. Copies of this document are available 

through the Bureau of Air Pollution Control. 

26 

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APPENDIXD 

LIGHT DUTY TESTING PROCEDURE 

The emission testing of light duty diesel powered vehicles registered in Salt Lake County shall 

be conducted using the following procedures: 

1. Verify GVWR on vehicle decal 

2. Inspect vehicle for unsafe or potentially damaging operation. (Leaking fluids, unusual 

engine noises, etc) 

3. Chock wheels 

4. Enter vehicle information into analyzer 

5. Press "MODE" button on RTTIOO to select 

"CONTINUOUS MODE" 

6. Press "TUNING" or "START" button- meter will 

begin tuning phase 

7. Insert probe in tailpipe 

8. Select proper stack (tailpipe) size 

9. When "CONTINUOUS MODE" appears on the 

screen, accelerate to 50 mph and press "STORE" 

when prompted by analyzer. Follow analyzer 

prompts through wide open throttle portion. Press 

"STORE" button when prompted by analyzer 

10. Press "PRINT" button to obtain printout 

11. Enter opacity readings into analyzer 

12. Remove probe from tailpipe 
LIGHT DUTY DIESEL TESTING PROCEDURES 

Light duty diesel powered vehicles will be tested usmg the procedures as outlined in 

Specifications for the Diesel Inspection and Maintenance Program. Copies of this document are 

available through the Bureau of Air Pollution Control. 

28 
APPENDIX E 

TESTING A HEAVY DUTY VEHICLE 

Step 1. Preconditioning and Preparation 

Testing cannot be performed if the meter environment 

temperature is less than 41 degrees Fahrenheit or greater 

than 110 degrees Fahrenheit. Temperatures outside of this 

range may produce inaccurate readings by the opacity meter. 

Any vehicle presented for testing must first be inspected 

visually for conditions which would present danger to the 

Inspector or to the facilities or equipment. Any condition 

which may affect the test results must also be corrected 

before testing can be performed. Some items of concern may 

be coolant leaks, fuel leaks, oil leaks, low fluid levels, 

continuous stalling of the engine, fluctuating RPM readings 

or leaking exhaust systems. Additional measures of 

preparation include blocking the wheels to prevent 

accidental movement of the vehicle, bringing the vehicle to 

normal operating temperature, and ensuring proper 

ventilation of the testing area. The vehicle should be 

accelerated to determine if the governor is operating 

correctly. If the Inspector notices any malfunctions or 

improper conditions during this preparation phase, the test 

should be discontinued until the appropriate repairs are 

performed. 

If the vehicle to be tested is equipped with a dual 

exhaust system, only the darkest stack will be used for 

testing. After the vehicle reaches normal operating 
temperature, a visual snap test is to be performed to 

determine which stack is producing the darkest exhaust. 

When the opacity meter is turned on it will perform a 

warm up sequence. Initial warm up time is between 6 and 9 

minutes. The probe is not to be installed into the exhaust 

stack during the warm-up phase or damage to the opacity 

meter may occur. The probe is only to be inserted into the 

exhaust stack during the "TUNING" phase. After the warm up 

period, which occurs each time the opacity meter is 

initially turned on, the "START" button must be pressed to 

begin the "TUNING" sequence. 

The vehicle information can be entered into the computer 

during the time in which the meter is "TUNING". To enter 

the information, select "OPACITY TEST" from the main menu. 

The Inspector must then enter an access code before the 

computer will proceed. The access code must be kept 

confidential and never divulged to other certified or noncertified persons. Disciplinary action will be taken 

against those persons who allow their access code to be used 

be another individual. After entering the access code and 

pressing "ENTER", the vehicle information screen will 

appear. ALL OF THE INFORMATION REQUESTED ON THE SCREEN MUST 

BE COMPLETED BEFORE CONTINUING. The information must be 

entered accurately to ensure a reliable data base. 

After all of the information is entered the computer will 

direct the operator to proceed with the test. 

Step 2. Vehicle Testing 
The operator must press the "START" button to begin the 

"TUNING" phase. During the tuning phase the opacity meter 

will ask for the exhaust stack diameter. If stack size is 

different than the default size of four inches, the correct 

size is to be entered at this time. This is accomplished by 

pressing either the "UP" or "DOWN" arrows. The probe should 

be inserted into the exhaust during the tuning phase. 

The opacity meter will now instruct the operator to 

"ACCELERATE". The accelerator pedal must be depressed 

RAPIDLY to full throttle and held (the opacity meter screen 

will read "HOLD RPM") until the measurement reading appears 

on the opacity meter screen. When the reading appears on 

the screen the accelerator pedal should be released. This 

sequence will be repeated, as directed by the opacity meter, 

until "TEST PASSED" or "TEST FAILED" appears on the screen. 

STEP 3. Certificate Completion 

Upon completion of the test, a Certificate of Compliance 

and a Vehicle Inspection Report must be obtained by 

pressing the "PRINT" button on the front of the opacity 

meter. The Inspector must sign the Certificate of Compliance 

and the Vehicle Inspection Report where indicated. The 

vehicle owner must also sign the Vehicle Inspection Report. 

The original copy of the Certificate is given to the 

vehicle owner for registration purposes. The vehicle owners 

copy of the Vehicle Inspection Report must not be stapled to 

the Certificate original. 
The original copy of the Vehicle Inspection Report is to 

be stapled to the copy of the Certificate of Compliance and 

remain at the inspection facility for audit purposes. 

If the vehicle failed the test, the original copy of the 

Vehicle Inspection Report must be filed chronologically at 

the inspection facility for review by the auditor. The copy 

of the Vehicle Inspection Report is to be given to the 

vehicle owner. 

If the vehicle returns for a retest, and passes the test, 

both the failed Vehicle Inspection Report and the passed 

Vehicle Inspection Report must be stapled to the station 

copy of the Certificate of Compliance. 

If the vehicle fails a retest, both of the failed Vehicle 

Inspection Reports must be stapled together and re-filed in 

the "Failed Vehicle File". 
REA VY DUTY DIESEL TESTING PROCEDURES 

Heavy duty diesel powered vehicles (16,001 and heavier GVWR) will be tested using the 

procedures as outlined in Specifications for the Diesel Inspection and Maintenance Program. This 

procedure is based on the Society of Automotive Engineers (SAE) paper 11667. Copies of the 

specification document and 11667 are available through the Bureau of Air Pollution Control. 

30 
APPENDIXF 

PENALTY SCHEDULE 

1st 2nd 3rd 

VIOLATION OCCURRENCE OCCURRENCE OCCURENCE 

Failure to Up to 2 mo. Revocation 

ins~~ct or suspension (Station & 

pro mg a (Station & Mechanic) 

vehicle other Mechanic) 

than vehicle 

entered in Revocation 

test record. (Mechanic) 

Non- Up to 2.mo. Revocation 

certified suspensiOn (Station & 

inspector (Station & Mechanic) 

Mechanic) 

Pass vehicle Up to l.mo. Up to 3 mo. Revocation 

that should suspensiOn suspension (Station & 

fail. Fail (Station & (Station & Mrlui:) 

vehicle that Mechanic) Mechanic) 

should pass 

(includmg 

tampering). 

Inaccurate or Formal warning Up to l.mo. Up to 3.mo. 

incomplete data suspensiOn suspension 

(additional violations may 

result in revocation) 

Failure to Formal warning Up to 1 mo. Up to 3.mo. 

follow suspension suspensiOn 

procedures. 

(additional violations may 

result in revocation) 

31 
' . \.. UTAH COUNTY 

DIESEL VEHICLE EMISSIONS INSPECTION/MAINTENANCE PROGRAM 

SECTION 

1.0 Definitions 

2.0 Purpose 

3.0 Jurisdiction of the Department 

4.0 Powers and Duties 

5.0 Scope 

6.0 General Provisions 

7.0 Standards and Specifications for Diesel Testing Equipment 

8.0 Permit Requirements for Diesel Inspection/Maintenance Program Fleet Stations 

9.0 Approval of Required Test Equipment 

10.0 Certification Requirements for Testing and Licensing of Applicants for Diesel Opacity 

Inspectors 

11.0 Inspection Procedure 

12.0 Certificates ofCompliance 

13.0 Certificates of Waiver 

14.0 Temporary Waivers 

15.0 Engine Changes 

16.0 Right to Appeal 

17.0 Penalty 

18.0 Severability 

19.0 Effective Date 

APPENDICES 

APPENDIX A Cutpoints 

APPENDIX B Fee Schedule 

APPENDIX C Diesel Opacity Inspection Equipment Specifications 

APPENDIX D Diesel Vehicle Opacity Inspection Procedures 

APPENDIX E Penalty Schedule 

Attachment 3 
1.0 DEFINITIONS. 

For the purpose of these Regulations, the following terms, phrases, and words shall have the 

following meanings, unless otherwise defined: 

1.1 Accuracy: is the degree of conformity of a measure to a standard or a true value. 

1.2 Basic Engine Systems: are those parts or assemblies which provide for the efficient 

conversion of diesel fuel into useful power to include, but not limited to, valve train mechanisms, 

cylinder heads, block, piston-ring-cylinder sealing integrity and post-combustion emissions control 

devices. 

1.3 Calibration: is the process of establishing or verifying the accuracy of test equipment. 

1.4 Certificate of Compliance: is the document which indicates that the smoke opacity levels 

from a diesel vehicle complies with applicable smoke opacity limits at the time of the inspection or 

after needed adjustments or repairs andre-inspection. 

1.5 Certificate of Waiver: is a document, issued by the Department, used to verify that a 

vehicle has met the repair or adjustment requirements of the Diesel Vehicle Emissions 

Inspection/Maintenance Program Regulations even though specific standards have not been met. 

1.6 Certification: is assurance by an authorized source, whether it be a laboratory, the 

manufacturer, the State, or the Department, that a specific product or statement is, in fact, true and 

meets all applicable requirements. 

1. 7 Certified Neutral Density Filter: is an optical quality filter which reduces the amount of 

transmitted light, an amount which is dependent upon the filter's optical density rating, uniformly 

across the visible light spectrum for the purpose of verifying the accuracy of the Diesel Opacity 

Analyzer. 

1.8 County: is Utah County, Utah. 

1. 9 Chassis Dynamometer or Dynamometer: is a vehicle power absorption device which has 

the ability to approximate or simulate actual on-road operation of motor vehicles through the 

application of variable loading. 

1.10 Clean-Out Cycle: is the wide open throttle accelerations used to purge the exhaust 

system of any residual exhaust prior to an Opacity Inspection applicable to Heavy Duty Diesel 

Vehicles. 

1.11 Cutpoints: are the maximum allowable smoke opacity limits for a given weight class 

and model year of a motor vehicle, as determined by the Department, using an approved Diesel 

Opacity Analyzer. 

1.12 Dedicated Printer: is the printer on the approved Diesel Opacity Analyzer which is used 

solely to print Certificates of Compliance. 

"J • 
1.13 Department: means the City-County Health Department ofUtah County. 

1.14 Diesel I/M Program Fleet Station: is a private or public fleet, of twenty five (25) or 

more vehicles, that has a valid permit, issued by the Department, to perform Diesel Opacity 

Inspections on their own vehicles in accordance with the Diesel Vehicle Emissions 

Inspection/Maintenance Program Regulations. 

1.15 Diesel Opacity Inspector: is an individual, employed by the Department or licensed by 

the Department, to perform Opacity Inspections on diesel vehicles. 

1.16 Diesel Opacity Inspection: is an inspection of a diesel powered vehicle by a Diesel 

Opacity Inspector, employed by a Diesel 1/M Program Fleet Station, or the Department. 

1.17 Diesel Opacity Inspectors Permit: is the permit issued by the Department to a Diesel 

Opacity Inspector after completing the required training course and passing all aspects of the 

practical hands-on and written test procedures. 

1.18 Diesel Opacity Analyzer: is an opacity meter with any additional hardware or software 

required by the Department to perform an official Diesel Opacity Inspection in accordance with 

these Regulations. 

1.19 Diesel Powered Motor Vehicle: includes only a motor vehicle which is operated with 

four wheels or more on the ground, propelled by a compression-ignited engine using diesel fuels. 

1.20 Diesel Vehicle Inspection/Maintenance Program: means the opacity inspection and 

repair program for diesel powered vehicles established by the Department, pursuant to Section 41-6-

163.8, Utah Code Annotated 1953, as amended. 

1.21 Director: means the Director of the City-County Health Department of Utah County or 

his or her authorized representative. 

1.22 Drift: refers to the amount that the Diesel Opacity Analyzer readings change, expressed 

as a percentage of full scale, over a period of time. 

1.22.1 Zero Drift: refers to no change of the zero reading when the Diesel Opacity 

Analyzer is in the zero mode. 

1.22.2 Span Drift: refers to the amount of change in reading when the Diesel Opacity 

Analyzer is in the span or full field mode. 

1.23 Emissions Control Systems: are those parts, assemblies or systems originally installed 

by the manufacturer in or on a vehicle for the specific purpose of reducing exhaust emissions. 

3 
1.24 Engine Rated RPM: means a specific rpm at which the manufacturer states that the 

engine's maximum/rated brake horsepower is attained. Above this rpm, the engine's governor will 

typically begin limiting full load fuel quantity and thus prevent the engine from developing full 

power beyond this rpm. Rated engine power and speed information is usually found on a label 

affixed to the engine itself or other underhood location. 

1.25 Exemption Form: is a document used to verify that a vehicle is exempt from the testing 

and repair/adjustment requirements of these Regulations. 

1.26 F AS: means Free Acceleration Smoke pertaining to engine acceleration at WOT with no 

load on the engine. 

1.27 GVWR: (Gross Vehicle Weight Rating) means the weight specified by the vehicle 

manufacturer as the maximum allowable loaded weight of a single vehicle. 

1.28 Heavy Duty Diesel Vehicle: as applicable to the Diesel Vehicle Inspection/ 

Maintenance Program refers to diesel vehicles with 16,001 pounds GVWR or more. 

1.29 High Altitude Specifications: are tune-up specifications that have been provided, by the 

manufacturer, to the Environmental Protection Agency for vehicles operating 4,000 feet or more 

above sea level. 

1.30 Idle Mode: is the condition where the vehicle engine is at operating temperature and 

running at an RPM rate specified by the manufacturer's curb idle speed, where the engine is not 

propelling the vehicle, and where the throttle is in the closed or idle stop position. This condition 

must be achieved without placing a load on the engine to decrease the RPM to the specified rate. 

1.31 Inspection Area: is the area that is occupied by the Diesel Opacity Analyzer, test 

equipment, and the vehicle being inspected. 

1.32 ISO: means International Standards Organization. 

1.33 Light Duty Diesel Vehicle: as applicable to the Diesel Vehicle Inspection/ Maintenance 

Program refers to diesel vehicles with 16,000 pounds GVWR or less. 

1.34 Maximum No-Load RPM or High Idle RPM: means the maximum rpm that the engine's 

governor will allow the engine to attain under no-load, wide open throttle (WOT) conditions. For 

many vehicular diesel engines, this rpm is typically 8 to 11% higher than the engine's rated rpm. 

1.35 Motor Vehicle: is a self propelled motorized vehicle with an internal combustion 

powered engine which is licensed for operation on public roads and/or streets. Motor Vehicles 

exempted from the inspection requirements of these Regulations are listed in Section 6.4 of these 

Regulations. 

4 
1.36 MPH: means Miles Per Hour. 

1.37 MSO: means Manufacturer's Statement of Origin, Manufacturer's Certificate ofOrigin, 

or similar such document accompanying each newly manufactured vehicle, provided by the new 

vehicle manufacturer. 

1.38 Non-Certified Inspector: is any person who has not been licensed by the Department to 

perform official Diesel Opacity Inspections. 

1.39 Off Highway Vehicles: are vehicles licensed to operate exclusively off highways. 

1.40 Opacity: means the degree to which the exhaust plume obscures the view expressed in 

percentage of obstruction, or the degree, expressed in percent, to which transmittance of light is 

reduced by the exhaust plume. 

1.41 Opacity Meter: means an optical instrument which is designed to provide continuous 

real-time measurement of the opacity of diesel exhaust gases and particulates which pass through the 

optical unit. 

1.42 Opacity Inspection: means the testing of diesel powered motor vehicles using 

procedures prescribed in this Regulation in order to determine the magnitude (expressed as a 

percentage) of obscured light (opacity) due to exhaust constituents, mainly fine particles. 

1. 43 Original Condition: is the condition of the emission control system( s) as installed by the 

manufacturer, but not necessarily to the original level of effectiveness. 

1.44 PMw: means particulate matter with an aerodynamic diameter less than or equal to a 

nominal 10 micrometers as measured by an EPA reference or equivalent method. 

1.45 Permit: is a document, issued by the Department, to a person or facility granting them 

authority to perform Diesel Opacity Inspections in accordance with these Regulations. 

1.46 Primary Residence: is the place which an individual lives more than six (6) months 

during a calendar year. 

1.4 7 Publicly-Owned Vehicles: are motor vehicles owned by a Government entity, including 

but not limited to the Federal Government or any agency thereof, the State OfUtah or any agency or 

political subdivision thereof. 

1.48 Repeatability: is the instrument's capability to provide the same value, within specified 

tolerances, for successive measurement of the same sample. 

1.49 RPM: means Revolutions Per Minute as pertaining to engine crankshaft speed. 

1.50 SAE: means Society of Automotive Engineers. 

1.51 Safety Inspection Certificate: is a certificate issued to a vehicle after it has been 

inspected and passed an official Utah Highway Patrol Safety Inspection performed by a licensed 

5 
safety inspection station. 

1.52 Strip Chart Recorder: is an instrument which receives and records data from one or 

more electrical inputs and displays that information in the form of a real-time, continuous (nonimpact) tracings on paper. 

1.53 Technical Bulletin: is a document, issued to Opacity Inspectors and/or Diesel I/M 

Program Fleet Stations by the Department to update, clarify or establish policies and/or procedures 

for their implementation in the Diesel Vehicle Inspection/Maintenance Program. 

1.54 Technical Centers: are those facilities operated by the Department for technical or 

administrative support of the Gasoline Inspection/Maintenance ·Program and Diesel Vehicle 

Inspection/Maintenance Program. 

1.55 Temporary Waiver: is a waiver that may be issued by the Director which will allow the 

temporary registration of a vehicle based upon a vehicle owner's compliance with the conditions of 

the waiver. 

1. 56 Training Program: means a formal program, administered, conducted, or approved by 

the Department, for the education of Diesel Opacity Inspectors in basic emission control technology, 

inspection procedures, diagnosis and repair of emissions related problems, Diesel I/M Program 

policies, procedures, and these Regulations. 

1.57 WOT: means Wide Open Throttle. 

2.0PURPOSE 

It is the purpose of these Regulations to reduce PM10 air pollution levels by requiring ammal 

inspections in accordance with the schedule adopted bv the Board ofCountv Commissioners ofboth 

light duty and heavy duty in-use diesel powered motor vehicles and by requiring emission related 

repairs/adjustments for those vehicles that fail to meet prescribed standards so as to: 

2.1 Protect and promote the public health, safety and welfare; 

2.2 Improve air quality; 

2.3 Comply with the Utah Air Conservation Committee requirements under 

26-13-6(8);and 

2.4 Comply with the law enacted by the Legislature of the State ofUtah, section 

163.8 Utah Code Annotated, 1953, as amended. 

6 

41-6-
,• 

3.0 JURISDICTION OF THE DEPARTMENT 

All aspects of the Diesel Vehicle Emission Inspection/ Maintenance Program within Utah 

County shall be subject to the direction and control of the Department. 

4.0 POWERS AND DUTIES 

4.1 The Department, by the Director, shall be responsible for the enforcement and administration 

of these Rules and Regulations and any other powers vested in it by law and shall: 

4.1.1 Require the submission of information, reports, plans, and specifications from Diesel 

1/M Program Fleet Stations as necessary to implement the provisions, requirements, and standards of 

these Regulations; 

4.1.2 Issue permits, certifications, and charge fees as necessary to implement the provisions, 

requirements and standards of these Regulations; 

4.1.3 Perform inspections (audits) of any Diesel 1/M Program Fleet Station, issue orders 

and/or notices, hold hearings, and levy administrative penalties, as necessary to affect the purpose of 

these Regulations; 

4.1.4 Take samples and make analysis required to ensure that the provisions of these 

Regulations are met; and 

4.1.5 Make policies and procedures necessary to ensure that the provisions of these 

Regulations are met and that the purposes of these Regulations are accomplished. 

4.2 The Department may suspend, revoke, negotiate a fee, or deny a permit of a Diesel 1/M 

Program Fleet Station and/or require the surrender of said permit and unused Certificates of 

Compliance of such Diesel I/M Program Fleet Station upon showing that: 

4.2.1 A vehicle was inspected and issued a Certificate by Diesel I/M Program Fleet Station 

personnel that did not, at the time of inspection, comply with all applicable policies, procedures, 

Technical Bulletins, and these Regulations; 

4.2.2 A Diesel liM Program Fleet Station allowed a Certificate of Compliance to be issued to 

a vehicle without an approved inspection being performed; 

4.2.3 The station has violated any provisions of these Regulations, or any Rule, Regulation, 

or Department policy properly promulgated for the operation of a Diesel liM Program Fleet Station; 

4.2.4 The station was not equipped as required by section 8.4.5 of these Regulations; 

4.2.5 The station was not operating from a location specified on the permit; 

7 
4.2.6 A Diesel Opacity Inspection was performed by an individual that at the time of the 

inspection did not hold a valid Diesel Opacity Inspectors Permit; 

4.2. 7 The station denies access, or fails to permit a representative of the Department to 

conduct an audit and/or inspection or conduct other necessary activities or business during regular 

business hours; 

4.2.8 A vehicle was inspected and issued a Certificate by a Diesel I/M Program Fleet Station 

that, at the time of inspection, exceeded permissible opacity levels as set forth in these Regulations, 

or technical bulletins. 

4.3 The Department may suspend, revoke, or deny the Permit of a Diesel Opacity Inspector and 

require the surrender of this Permit upon showing that: 

4.3 .1 The Diesel Opacity Inspector issued a Certificate of Compliance to a vehicle without 

performing a Diesel Opacity Inspection on that vehicle; 

4.3.2 The Diesel Opacity Inspector denied the issuance of a Certificate of Compliance to a 

vehicle that, at the time of the inspection, complied with these Regulations; 

4.3.3 The Diesel Opacity Inspector issued a Certificate of Compliance to a vehicle that, at the 

time of issuance, was in such condition that it did not comply with these Regulations; 

4.3.4 The Diesel Opacity Inspector knowingly allowed a Non-Certified Inspector to perform 

a Diesel Opacity Inspection, or any portion of a Diesel Opacity Inspection; 

4.3.5 The Diesel Opacity Inspector signed an inspection form or certificate stating that he 

had performed the inspection when, in fact, he/she did not; 

4.3 .6 The Diesel Opacity Inspector signed a Certificate of Compliance prior to an inspection 

being performed. 

4.4. The Department shall respond, according to the policies and procedures of the Department, to 

public complaints regarding the integrity of inspections performed at Diesel I/M Program Fleet 

Stations. 

4.5 The Department, or their representative, is responsible for performing all Opacity Inspections 

on Light Duty Diesel Vehicles. 

4.6 The Department is responsible for administering all aspects of the Heavy Duty Diesel Opacity 

Inspections. 

4.6.1 The Department may perform periodic Opacity Inspections, during normal business 

hours, on any vehicle that has or will be inspected by a Diesel I/M Program Fleet Station. 

4. 6.2 Heavy Duty Diesel Vehicles that are not included as part of a Diesel liM Program Fleet 

8 

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,• 

Station shall be inspected by the Department. Inspections may be performed at the Department 

facilities or at another specified location. 

5.0 SCOPE 

It is unlawful for any person not to comply with any policy, procedure, Technical Bulletin, or 

Regulation promulgated by the Department, unless expressly waived by these Regulations. 

6.0 GENERAL PROVISIONS 

Subject to the exceptions described in section 6.4 and pursuant to the schedule in section 6.1 

and 6.1.1, individuals with their primary residence in Utah County must register their diesel powered 

vehicles in Utah County. Diesel powered motor vehicles that are or will be registered in Utah 

County, or operated from a facility within Utah County, shall be subject to a Diesel Opacity 

Inspection performed by a Diesel 1/M Program Fleet Station, a Department operated test facility or 

other entity approved by the Director. 

6.1 Beginning December 1, 1994 a Certificate of Compliance or Waiver, or evidence that the 

motor vehicle is exempt from the Diesel 1/M Program requirements (as defined in section 6.4) shall 

be presented to the Utah County Assessor or the Utah State Tax Commission and the Air Pollution 

Control Fee paid as conditions precedent to annual registration or annual renewal of registration of a 

motor vehicle. 

6.1.1 The beginning date listed herein may be temporarily postponed if it is deemed 

necessary by the Director to aid in the smooth and effective implementation of the Diesel Vehicle 

Inspection/Maintenance Program. The temporary postponement of the program beginning date may 

be implemented if it is determined by the Director that the integrity of the program may be 

jeopardized because testing equipment, procedures, facilities, software or other aspects of the 

program are not ready for effective and accurate testing to begin. Different start-up dates may be 

selected for light duty and heavy duty vehicles. 

6.2 A Certificate of Compliance or Waiver issued to a dealer licensed with the State ofUtah and 

issued in the dealer's name, shall be valid for registration purposes for a period of six months as 

specified in section 41-3-28.5, Utah Code Annotated, 1953, as amended. The purchasers name, 

address, and phone number shall be recorded by the dealer on the back of the Certificate. 

6.3 Vehicle fleet owners shall comply with the Diesel Vehicle Inspection/ 

Maintenance Program requirements pursuant to a schedule determined by the Department. 

Federally-owned vehicles and vehicles of employees operated on a federal installation that do not 

require registration in the State of Utah shall comply with the Diesel Vehicle 

Inspection/Maintenance Program requirements pursuant to a schedule determined by the 

Department. 

6.4 The following vehicles are exempt from these Regulations: 

9 
6.4.1 All agricultural implements of husbandry not registered for highway use; 

6.4.2 Any vehicle used for maintenance or construction and not designed or licensed to 

operate on the highway; 

6.4.3 Any vehicle registered as an Off Highway Vehicle; 

6.4.4 Any new vehicle being sold for the first time that has a valid MSO (manufacturers 

statement of origin) form. 

6.5 Owners of private or publicly owned Heavy Duty Diesel vehicles may request that a Health 

Department representative perform an on-site Diesel Opacity Inspection at a location other than a 

County owned test facility. On-site inspections by the Health Department shall only be performed in 

accordance with the following requirements: 

(a) On-site Diesel Opacity Inspections shall only be performed when there are five (5) or 

more vehicles at one test site. These vehicles may be owned by the same or different individuals. 

(b) All vehicle owners must provide proof to the Department that the vehicle has passed a 

Utah Highway Patrol safety inspection within the last two (2) months. 

(c) All test sites must comply with local zoning ordinances for the performance of these 

inspections and be approved by the Department prior to inspections being performed. 

(d) On-site Diesel Opacity Inspections for emergency response vehicles will not be subject to 

a minimum number of vehicles at one location and may be allowed a zoning variance if necessary to 

allow tests to be performed at their location. 

6.6 Required tools and equipment as noted in section 8.4.5, supplies, records, unused Certificates 

of Compliance, and other required forms, shall be kept at the Diesel I/M Program Fleet Station at all 

times and shall be available for inspection or collection by the Department at any time the Diesel 

I/M Program Fleet Station is open for business. 

6.6.1 Records of completed inspections and duplicate copies of Certificates of Compliance 

issued shall be kept at the Diesel liM Program Fleet Station at all times for a period of not less than 

eighteen (18) months and shall be available for inspection or collection by the Department at any 

time the Diesel I/M Program Fleet Station is open for business. 

6.6.2 A periodic inspection and audit shall be made by a Department representative to verify 

compliance with these Regulations for each Diesel liM Program Fleet Station. As part of the 

periodic inspection and audit of the Diesel I/M Program Fleet Station the Department representative 

shall, as applicable, observe the performance of an electronic equipment calibration performed by 

the Diesel Opacity Inspector, examine calibration records, and Certificates of Compliance as well as 

other required reports, forms, or records to verify that the use of these items are in compliance with 

these Regulations and the policies and procedures of the Department. 

10 

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6.6.3 During the station inspection and audit by the Department, the Department 

representative shall have exclusive access to the Diesel Opacity Analyzer. 

6.6.4 The Department representative may check the accuracy of the Diesel Opacity Analyzer 

using Department audit procedures to verify that the equipment is reading within the tolerances 

established by the Department. Diesel Opacity Analyzers not reading within the audit tolerances 

shall be recalibrated to within acceptable tolerances or be placed "out of service". 

6. 7 FEES. The fees assessed upon Diesel liM Program Fleet Stations and the Diesel Opacity 

Inspectors shall be determined according to the fee schedule adopted by the Department. The fee 

schedule as referenced in Appendix B to these regulations and may be amended by the City-County 

Board of Health as the Board deems necessary to accomplish the purpose of these Regulations. 

6. 7.1 Diesel emissions inspection fee shall not exceed the amount specified in Appendix B. If a 

vehicle fails the inspection the owner is entitled to one reinspection not to exceed the reinspection 

fee specified in Appendix B ifhe/she returns to the Department within thirty (30) days from the date 

of the initial inspection. The Department shall extend the thirty day reinspection time to 

accommodate the vehicle owner if the Department is unable to schedule the retest of the vehicle 

within the thirty day time period. 

6. 7.2 Duplicate Certificates of Compliance or Waiver may be issued to a vehicle owner/operator 

within two months of the initial test, fees may not exceed the amount specified in Appendix B. 

6.8 VEHICLE IDLING LIMITATION. It shall be unlawful for any owner or operator of any 

Heavy Duty Diesel Vehicle to cause or permit the same to be idled for a period in excess of fifteen 

(15) consecutive minutes, or for a period in excess of forty-five ( 45) minutes in any one hundredtwenty (120) minute period (it being the intent of this provision that an owner or operator may not 

circumvent the provisions of this section by repeated turning on and off of a diesel engine). 

6.8.1 EXEMPTION TO IDLING LIMITATIONS. Vehicles may be exempted from the 

idling limitation requirements of Section 6.8 under the following conditions: 

a) To supply power to a refrigeration unit for the purpose of cooling the contents of 

a trailer. 

b) To provide heat or air conditioning to a sleeper unit of the vehicle. 

c) Emergency response vehicles. 

6.8.2 Vehicles exempted from the Vehicle Idling Limitations as applicable under Section 

6.8.1 (a), (b) of these Regulations shall not remain in an idling condition for a period longer than 

fifteen (15) consecutive minutes, or for a period in excess of forty-five (45) minutes in any one 

hundred-twenty (120) minute period if located within five hundred (500) feet of any residence. 

7.0 STANDARDS AND SPECIFICATIONS FOR DIESEL TESTING EQUIPMENT 

11 
7.1 No Diesel Opacity Inspection required by these Regulations shall be performed unless the type 

of instrument used for measuring exhaust opacity from diesel powered motor vehicles is contained in 

the list of approved test equipment as provided by the Department. The test equipment shall meet the 

requirements of the equipment specifications referenced in Appendix C of these Regulations. The 

test equipment shall be in good working condition, shall comply with calibration requirements of the 

Department, and shall be operated according to manufacturer's specifications and operating 

procedures. 

7.2 Any test equipment being used to perform Diesel Opacity Inspections shall be registered with 

and approved by the Department and, if required, shall bear a registration sticker issued by the 

Department. Registration stickers are not transferable or assignable. Any new or used test equipment 

put in use after station approval must be approved by the Department before use. Test equipment 

used temporarily during times ofbreakdown or repair of the registered equipment do not require a 

registration sticker but shall meet all other requirements of this section including the approval of the 

Department before being used to perform Diesel Opacity Inspections. 

7.3 The test equipment printers shall be maintained in such a manner that the printing of the test 

results shall be clearly visible on all copies. If any printer fails to properly function, then the station 

shall discontinue testing until the required repairs have been performed. 

7.4 It shall be unlawful for any person to modify the hardware or the software of an approved 

Diesel Opacity Analyzer without written application and written approval by the Department. 

7.5 Documentation, Logistics, and Warranty Requirements. 

7.5.1 Instruction Manual: An instruction manual shall accompany each Diesel Opacity 

Analyzer and shall contain at least the following information for the analyzer: 

(a) A complete technical description; 

(b) The functional mechanical and electrical schematics; 

(c) The accessories and options that are included and/or available; 

(d) The model number, identification marking and location; 

(e) Operating maintenance including daily, weekly, and monthly, accommodations for 

maintaining sample system integrity including, but not limited to, leaks, hang-up, calibration and 

filters. The services to be performed only by the manufacturer shall be clearly identified; 

(f) Information concerning the nearest service facility where the equipment can be serviced; 

and 

(g) The warranty provisions for the analyzer, including a list of warranty repair stations by 

name, address and telephone number. 

7.5.2 The analyzer shall be maintained in accordance with the manufacturer's recommended 

maintenance schedule and records of maintenance service shall be maintained for examination by 

the Department. 

7.6 Calibration ofDiesel Opacity Analyzers 

12 
7.6.1 A Diesel Opacity Inspector shall perform a mechanicaVelectrical equipment calibration 

on the Diesel Opacity Analyzer following the manufacturer's recommended procedures not more 

than three (3) days prior to an official Diesel Opacity Inspection. Said calibration will be performed 

with a known source of laboratory certified light absorbing material such as a Certified Neutral 

Density Filter or other device approved by the Department. 

7.6.2 A Diesel Opacity Inspector shall perform an electrical zero and span check on the 

Diesel Opacity Analyzer following the analyzer manufacturer's procedures prior to each official 

Diesel Opacity Inspection. A Diesel Opacity Analyzer that fails the zero and span check shall be 

cleaned or recalibrated following manufacturer's recommendations. 

7.6.3 If the Diesel Opacity Analyzer requires repairs in order to be used in accordance with 

these Regulations, the Diesel 1/M Program Fleet Station shall discontinue use of the Diesel Opacity 

Analyzer and notify the Department that the analyzer is "Out-of-Service" and shall again notify the 

Department after repairs are made and before testing is resumed. 

7.6.4 The Diesel Opacity Analyzer instruction manual and other Department approved 

information shall be reviewed by the Diesel Opacity Inspector to ensure that proper procedures are 

being used for performing the calibration check. 

8.0 PERMIT REQUIREMENTS FOR DIESEL INSPECTION/MAINTENANCE PROGRAM 

FLEET STATIONS 

Owners of vehicle fleets with twenty five (25) or more Heavy Duty Diesel Vehicles may 

apply to the Director for a Diesel liM Program Fleet Station permit. This permit would allow fleet 

owners to inspect only their own vehicles that are registered to the individual or corporation 

identified on the permit. 

8.1 The Director is authorized to issue or deny Diesel 1/M Program Fleet Station permits. 

8.2 No Diesel 1/M Program Fleet Station permit may be assigned, transferred, or used by any 

person other than the original owner identified on the Diesel 1/M Program Fleet Station permit. The 

Diesel 1/M Program Fleet Station permit shall be posted in a conspicuous place within public view 

on the premises. 

8.3 The Diesel 11M Program Fleet Station must be at a permanent location which meets all 

applicable zoning requirements to provide for the inspection of diesel vehicles, as licensed, and as 

defined in these Regulations. 

8.4 Application for a Diesel 11M Program Fleet Station permit shall be made to the Department on 

a form provided by the Director. No Diesel 1/M Program Fleet Station permit shall be issued unless 

the Director finds that the facilities, tools and equipment of the applicant comply with the 

requirements of these Regulations and that competent personnel, certified under the provisions of 

section I 0.0, are employed and will be available to make inspections, and the operation thereof will 

13 
be properly conducted in accordance with these Regulations. 

8.4.1 Each Diesel 1/M Program Fleet Station will assign one individual, either a manager or 

an Inspector, the responsibility of resolving any problems or addressing any concerns that a 

Department representative may identify. The selected individual or his representative will be at the 

Diesel liM Program Fleet Station and available during normal business hours. The selected 

individual's name and title will be listed on the Diesel liM Program Fleet Station permit application 

form. 

8.4.2 A Diesel liM Program Fleet Station shall immediately notify the Department and 

immediately surrender all unused Certificates of Compliance at such time as the Diesel liM Program 

Fleet Station no longer employs a Diesel Opacity Inspector. 

8.4.3 A Diesel liM Program Fleet Station shall notify the Department whenever five (5) or 

more consecutive Diesel Opacity Inspections are scheduled to be performed within an eight (8) hour 

period. The Director, at his discretion, may dispatch a field auditor to observe all of or a portion of 

the Diesel Opacity Inspections performed. 

8.4.4 A Diesel liM Program Fleet Station shall comply with all terms stated in the permit 

application and all the requirements of these Regulations. 

8.4.5 As a condition for permitting all Diesel liM Program Fleet Stations, the following tools 

shall be available for performance of the inspection and maintenance of diesel powered motor 

vehicles: 

(a) A Department approved Diesel Opacity Analyzer that meets the minimum 

specifications as outlined in APPENDIX C of these Regulations; 

(b) A Department approved personal computer capable of meeting the minimum 

specifications as outlined in APPENDIX C of these Regulations; 

(c) A handbook, approved by the Department, that includes testing procedures to be 

followed by the Diesel Opacity Inspector; 

(d) An accurate strip chart recorder or other recording device capable of recording 

Diesel Opacity Inspection data for analysis; 

(e) Reference manuals approved by the Department that contain tune up 

specifications, and information covering the emissions control systems for the model years and 

makes of vehicles involved in the Diesel Vehicle Emissions Inspection/Maintenance Program; 

(f) Sufficient hand tools for proper performance of inspection and maintenance of the 

vehicle; 

(g) Exhaust gas removal equipment approved by the Department; 

(h) The Diesel Opacity Analyzer manufacturer's maintenance and calibration manual 

which must remain in the inspection area; 

(i) All forms, Technical Bulletins, and other information materials provided by the 

Department. 

14 
8.4.6 All facets ofthe Diesel Vehicle Emissions Inspection/Maintenance Program shall be 

performed by the Diesel Opacity Inspector including: 

8.4.6.1 Diesel Opacity Inspection equipment preparation, and calibration checks; 

8.4.6.2 Exhaust sampling and analysis for the purpose of a Diesel Opacity Inspection 

for issuance of a Certificate of Compliance; 

8.4.6.3 Preparation of reports, forms, certificates; and 

8.4.6.4 All other aspects of the official Diesel Opacity Inspection including but not 

limited to; the tampering inspection, inserting or attaching the exhaust opacity sampling equipment, 

hooking up the tachometer, entering the data, preconditioning the vehicle, and signing Certificates 

and inspection forms. 

8.4.7 A Diesel I/M Program Fleet Station shall be kept in good repair and in safe condition 

for inspection purposes free of obstructions and hazards. 

8.5 PERMIT DURATION AND RENEWAL 

8.5.1 Diesel liM Program Fleet Station Permits shall be issued annually and shall expire one 

year from date of issuance. The Permit shall be renewable sixty (60) days prior to the date of 

expiration. 

8.5.2 It is the responsibility of the owner/operator of the Diesel I/M Program Fleet Station to 

timely apply for a renewal of Diesel I/M Program Fleet Station Permits with the Department. 

8.5.3 Diesel I/M Program Fleet Station to hold Department Harmless: In making application 

for a Diesel I/M Program Fleet Station permit or for its renewal, such action shall constitute a 

declaration by the applicant that the Department shall be held harmless from liability incurred due to 

action or inaction of Diesel I/M Program Fleet Station's owners or their employees. 

9.0 APPROVAL OF REQUIRED TEST EQUIPMENT 

9.1 Diesel Opacity Inspections required by these Regulations shall not be performed unless the 

equipment used meets the specifications as defined in this Regulation and as approved by the 

Department. 

9.2 Any changes to the design or performance characteristics of component specifications which 

may affect the equipment or instrument performance must be approved by the Department. It shall 

be the instrument manufacturer's responsibility to confirm that such changes have no detrimental 

effect on the opacity meter or other equipment or instrument performance. 

15 
10.0 CERTIFICATION REQUIREMENTS FOR TESTING AND LICENSING OF 

APPLICANTS FOR DIESEL OPACITY INSPECTORS 

10.1 No person shall perform any part of a Diesel Opacity Inspection for the issuance of a 

Certificate of Compliance or Waiver unless the person possesses a valid Diesel Opacity Inspector's 

Permit issued by the Department. 

10.2 Applications for a Diesel Opacity Inspector Permit shall be made on a form to be prescribed 

by the Department. No Diesel Opacity Inspector Permit shall be issued unless the applicant complies 

with the requirements of this section. 

(a) An applicant shall demonstrate knowledge, skill, and competence concerning the 

operation and theory of diesel-fueled internal combustion engines. 

(b) An applicant shall complete a Department approved training course and shall 

demonstrate knowledge , skill, and competence by passing a written and performance qualification 

test including, but not limited to, knowledge of the following: 

i. Knowledge of the Rules and Regulations of the Diesel Vehicle Inspection/Maintenance 

Program; 

ii. Operation of and proper use, care, maintenance, and calibration of the Department 

approved Diesel Opacity Analyzer; 

iii. Proper use and distribution of the required inspection forms, Certificates, calibration 

records, and supplemental documents, and 

iv. Waiver requirements for all diesel vehicles failing the initial Diesel Opacity Inspection. 

(c) Requalification requirements for Diesel Opacity Inspectors. 

i. Upon determination by the Director of the necessity of updating the qualifications for 

Diesel Opacity Inspectors, they shall be required to requalify. Requalification requirements shall be 

determined by the Director. 

ii. Diesel Opacity Inspectors shall be required to recertify annually. Failure to recertify 

within the required period oftime shall result in the suspension or revocation of the Diesel Opacity 

Inspector's permit as described in these Regulations. 

(d) The Diesel Opacity Inspector's Permit shall be valid only at the station where the 

Inspector is presently employed. If the Inspector is later employed at another Diesel I/M Program 

Fleet Station, the Inspector shall notify the Department of the employment change. The Inspector 

shall reapply for a permit at the new location and pay the required fees. Prior to testing at the new 

location, the Inspector shall be permitted there and a new Permit number shall be issued. This Permit 

shall expire on the same date as the original. 

10.3 Permit Expiration 

10.3.1 The Diesel Opacity Inspectors Permit shall be issued annually and shall expire one 

16 
year from the date of issuance. The Diesel Opacity Inspector's Permit shall be renewable sixty (60) 

days prior to the date of expiration. 

10.3.2 It is the responsibility ofthe Diesel Opacity Inspector to pursue the renewal of the 

Permit. 

11.0 INSPECTION PROCEDURE 

11.1 No Light Duty Diesel Vehicle may receive a Diesel Opacity Inspection unless that vehicle has 

been submitted to and passed a Utah Highway Patrol Vehicle Safety Inspection as required by the 

Legislature of the State of Utah, section 41-6-158 Utah Code annotated, 1953, as amended. Proof of 

the inspection shall be in the form of a valid Safety Inspection Certificate. 

11.2 The Diesel Opacity Inspection shall be performed by a Diesel Opacity Inspector who has 

been certified to perform Diesel Opacity Inspections at the location where the inspection is being 

performed. 

11.3 The entire Diesel Opacity Inspection shall take place within the reach of the Diesel Opacity 

Analyzer's hoses and/or electrical leads. 

11.4 The temperature of the Inspection Area shall be not less than 41 o Fahrenheit and not more 

than 110° Fahrenheit during the inspection. 

11.5 The Diesel Opacity Analyzer shall be kept in an area that provides adequate protection from 

the weather, wind, and temperature extremes. 

11.6 The electrical supply to the Diesel Opacity Analyzer shall meet the equipment manufacturer's 

requirements for voltage and frequency stability. 

11.7 The Diesel Opacity Inspector shall not inspect or test any motor vehicle with a mechanical 

condition which may cause injury to inspection personnel or damage to the inspection station or test 

equipment or which may affect the validity of the test, until such condition is corrected. Such 

conditions include, but are not limited to: coolant, oil, or fuel leaks, low oil or low fluid levels, and 

high visible emissions. 

11.8 Any time an engine stalls during a Diesel Opacity Inspection, the test shall be restarted. If an 

Inspector cannot complete a test because of continuous stalling, fluctuating RPM measurements, or 

RPM measurements that are not within the Department specified parameters, these conditions shall 

be corrected before the test is continued. 

11.9 The Diesel Opacity Inspector shall accurately identify and enter vehicle and owner 

information from the vehicle to be tested as required by the data entry process of the Diesel Opacity 

Analyzer. 

11.10 During testing, for vehicles with multiple exhaust outlets the sample shall be taken from the 

17 
exhaust outlet which emits the heavier smoke, if there is a difference in smoke levels. 

11.11 The Diesel Opacity Inspector shall determine the appropriate test procedure to follow 

depending on the vehicle weight rating and type and then proceed with the test procedures as 

outlined in APPENDIX D of these Regulations. 

11.11.1 If a vehicle is unable to be tested using a particular weight category test procedure as 

outlined in APPENDIX D because of an unusual engine/chassis configuration. The Director, at his 

discretion, may select an alternate test procedure to be performed on the vehicle. 

12.0 CERTIFICATES OF COMPLIANCE 

12.1 No person shall make, issue, or knowingly use any imitation or counterfeit Certificate of 

Compliance. 

12.1.1 No person shall knowingly use stolen or counterfeit Certificates. 

12.2 Certificates of Compliance shall be purchased only from the Department. 

12.3 No refund or credit shall be allowed for unused certificates, except as provided in Section 

12.9. 

12.4 Purchase of Certificates of Compliance 

12.4.1 Sales of Certificates of Compliance shall only be made to a representative of the 

Diesel I/M Program Fleet Station possessing an acceptable form of identification. 

12.4.2 Certificates of Compliance shall be sold at a cost adopted by the City-County Board of 

Health and referenced in Appendix B, in lots to be determined by the Department. The Department 

may limit the number of certificates purchased to the number that the Department feels can be 

secured and stored safely. 

12.4.3 Certificates of Compliance shall not be sold, loaned, transferred, or given to any other 

Diesel I/M Program Fleet Station, or any other individual or entity. The Diesel liM Program Fleet 

Station shall at all times account for all Certificates of Compliance that have been purchased by the 

station. 

12.5 Certificates of Compliance shall not be issued until a vehicle has received a Diesel Opacity 

Inspection, the results of which comply with the terms of these Regulations. 

12.6 All unused Certificates of Compliance shall be kept in a secure place at all times to prevent 

loss or theft. 

12.7 Certificates of Compliance shall be used in sequential order by Diesel I/M Program Fleet 

18 

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Stations. 

12.8 Certificates of Compliance found to be missing, stolen, or unaccounted for, shall be reported 

to the Department within twenty four (24) hours and the station shall cease performing Diesel 

Opacity Inspections until the Department reauthorizes the station to again begin testing. 

12.9 Upon final cancellation, suspension or revocation of the Diesel I/M Program Fleet Station 

Permit of any station, the station owner, manager or other responsible person shall immediately 

surrender all unused Certificates of Compliance to the Department. The Department shall receipt and 

refund the fee paid for unused Certificates of Compliance to the station owner according to the Utah 

County Auditor's procedures. Upon transfer or termination of business ownership, the Diesel I/M 

Program Fleet Station permit and all Certificates of Compliance shall be immediately surrender to 

the Department. Any person acquiring a business that has been permitted as a Diesel I/M Program 

Fleet Station, is prohibited from performing Diesel Opacity Inspections under the authority of any 

such permit or from issuing Certificates of Compliance which were issued to the previous owner. 

13.0 CERTIFICATES OF WAIVER 

13.1 No person shall make, issue, or knowingly use any imitation or counterfeit Certificate of 

Waiver. 

13.1.1 No person shall knowingly use stolen or counterfeit Certificates. 

13.2 If it is determined by the Director that a particular vehicle can not be tested using any current 

test procedures, the Director may issue a Waiver allowing the vehicle to be registered until an 

alternate test procedure is developed. 

13.3 Certificates of waiver shall only be issued by the Department unless the Department 

determines other acceptable methods of issuing the waivers. A waiver shall only be issued after 

determining that the vehicle complies with the requirements of this section for waiver issuance. 

13.4 A Certificate of Waiver may be issued for Light Duty Diesel vehicles if all of the following 

requirements are met: 

13 .4.1 Air pollution control devices that were originally installed by the manufacturer are in 

place and operable on the vehicle. If the devices have been removed or rendered inoperable, they 

shall be replaced or repaired before a Waiver is granted. Costs for repairs or replacement of pollution 

control equipment will not be included in waiver repair costs; 

13.4.2 Any applicable High Altitude Adjustments have been performed following the 

manufacturers recommended procedures; 

13.4.3 The vehicle continues to exceed applicable opacity standards after $750 (seven 

hundred and fifty dollars) of acceptable emissions related repairs have been performed after the first 

Diesel Opacity Inspection failure. Proof of repair costs shall be provided for the vehicle to the 

19 
Department in the form of a dated, itemized bill, invoice, work order, manifest or statement in which 

emissions related parts are specifically identified. If repairs are made by the vehicle owner or by 

someone who does not possess a valid business license for automobile or truck repair, then the cost 

of labor shall not be included in determining the cost of acceptable emission related repairs, and 

13.4.4 Any vehicle that does not experience any improvement in Opacity levels since the 

first Diesel Opacity Inspection shall not be eligible for an emissions repair waiver regardless of the 

amount spent in attempting to repair the vehicle. 

13.5 A Certificate ofWaiver may be issued for Heavy Duty Diesel vehicles if all of the following 

requirements are met: 

13.5.1 Air pollution control devices that were originally installed by the manufacturer are in 

place and operable on the vehicle. If the devices have been removed or rendered inoperable, they 

shall be replaced or repaired before a Waiver is granted. Costs for repairs or replacement of pollution 

control equipment will not be included in the repair Waiver; 

13.5.2 Any applicable High Altitude Adjustments have been performed following the 

manufacturers recommended procedures; 

13.5.3 The vehicle continues to exceed applicable opacity standards after $1500 (fifteen 

hundred dollars) of acceptable emissions related repairs have been performed after the first Diesel 

Opacity Inspection failure. Proof of repair costs shall be provided for the vehicle to the Department 

in the form of a dated, itemized bill, invoice, work order, manifest or statement in which emissions 

related parts are specifically identified. If repairs are made by the vehicle owner or by someone who 

does not possess a valid business license for automobile or truck repair, then the cost of labor shall 

not be included in determining the cost of acceptable emission related repairs, and 

13.5.4 Any vehicle that does not experience any improvement in Opacity levels since the 

first Diesel Opacity Inspection shall not be eligible for an emissions repair waiver regardless of the 

amount spent in attempting to repair the vehicle. 

14.0 TEMPORARY WAIVERS 

14.1 For all vehicles, if a part or parts which are necessary to bring a vehicle into compliance with 

these Regulations is/are not available at the time the vehicle's registration is due, the owner/operator 

may obtain a signed form to that effect from a manufacturer, dealer, or mechanic who has verified 

the non-availability of the part(s). The owner/operator shall then take such proof to the Department. 

The Director may issue a Temporary Waiver, for a period oftime and under such conditions as he 

determines, so that the vehicle may be registered ifthe Temporary Waiver is issued. The owner shall 

have until the expiration of the time period specified by the Director to complete the necessary 

repairs or replacement, and submit a Certificate of Compliance or Waiver to the Director to verify 

that the part( s) have been installed and that the vehicle is in compliance with all provisions of these 

Regulations. The Director is under no obligation to issue Temporary Waivers under this section. 

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14.2 Under certain conditions as determined by the Director, the Director may issue a Temporary 

Waiver enabling a vehicle to be registered. The person to whom the Temporary Waiver is issued 

shall comply with the conditions of the Temporary Waiver as agreed upon by a signed affidavit. 

Failure to comply with the affidavit shall be considered a violation of these Regulations. The 

Director is under no requirement or obligation to issue Temporary Waivers under this section. 

15.0 ENGINE CHANGES 

Vehicles that have had their original engine changed, shall be tested to the Cutpoints 

applicable to the model year of the vehicle. This shall apply regardless of the year of the engine. If 

pollution control equipment that would have been installed on the original engine is missing, than 

that equipment would have to be reinstalled before the vehicle would become eligible for a waiver. 

Costs associated with such repairs would not apply towards the waiver amount. If the engine has 

been converted from diesel fuel to another type of fuel, the vehicle must comply with the regulations 

governing the type of fuel which is being used in the vehicle. 

16.0 RIGHT TO APPEAL 

Within ten (10) calendar days after the Department has given notice ofviolation(s), permit 

denial, revocation, or suspension, any person( s) aggrieved may request in writing a hearing before 

the Department. The written request for hearing shall be made on a form provided by the 

Department. The hearing shall take place within ten ( 1 0) calendar days after the request is received. 

A written notice of the Director's final determination shall be given within ten (10) calendar days 

after adjournment of the hearing. The Director may sustain, modify, or reverse the action or order. 

17.0 PENALTY 

17.1 Any person who is found guilty of violating any of the provisions of these Rules and 

Regulations, either by failing to do those acts required herein or by doing a prohibited act, shall be 

guilty of a class B misdemeanor pursuant to Section 26A-1-123, Utah Code Annotated, 1953, as 

amended. If a person is found guilty of a subsequent similar violation within two years, he shall be 

guilty of a class A misdemeanor pursuant to Section 26A-1-123, Utah Code Annotated, 1953, as 

amended. 

17.2 Each occurrence such violation is committed or permitted to continue shall constitute a 

separate violation. 

17.3 The City Attorney, or, if appropriate, the County Attorney, may initiate legal action, civil or 

criminal, to abate any condition that exists in violation of these Rules and Regulations. 

17.4 In addition to other penalties imposed by a court of competent jurisdictions, any person( s) 

found to be in violation of any of these Rules and Regulations shall be liable for all expenses 

including a reasonable attorney's fee and costs of court incurred by the Department, City Attorney or 

County Attorney incurred in any enforcement proceeding to enforce these Regulations, whether civil 

21 
or criminal. 

1 7. 5 The penalty schedule referenced in Appendix E may be amended by the Department as the 

Department deems necessary to accomplish the purpose of these Regulations. 

18.0 SEVERABILITY 

If any provision, clause, sentence, or paragraph of these Regulations or the application 

thereof to any person or circumstances shall be held to be invalid, such invalidity shall not affect the 

other provisions or applications of these Regulations. The valid part of any clause, sentence, or 

paragraph of these Regulations shall be given independence from the invalid provisions or 

application and to this end the provisions of these Regulations are hereby declared to be severable. 

19.0 EFFECTIVE DATE 

These Regulations shall become effective the day of their enactment by the City-County Board of 

Health of Utah County. The appendices become effective on the specific date found on each of the 

appendices. 

22 

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APPENDIX A 

UTAH COUNTY DIESEL OPACITY 

CUTPOINTS 

Effective Date: May 1, 1995 

DIESEL VEHICLE EMISSIONS INSPECTION/MAINTENANCE PROGRAM 

The following schedule gives the maximum allowable opacity levels for both cars and trucks 

as determined by an approved smokemeter using the prescribed test procedures. 

All passenger vehicles and light duty trucks 16,000 GVWR or less. 

Maximum Opacity Levels 

Model Year Engine Type Opacity 

1973 and older All 40% 

197 4 and newer Naturally Aspirated 35% 

197 4 and newer Turbocharged 30% 

All heavy duty trucks 16,001 GVWR or more. 

Maximum Opacity Levels 

Model Year Engine Type Opacity 

All Naturally Aspirated 70% 

All Turbocharged 70% 

Note: These should be considered as "cutpoints" for maximum allowable opacity levels. 

Vehicles must never be reset to these opacity levels when readjustments are made, but rather 

shall be adjusted using manufacturer's specifications. By using manufacturer's specifications, 

the opacity levels should be well below the "cutpoints". 

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APPENDIX B 

FEE SCHEDULE 

Effective Date: December 1, 1994 

The assessed fees for implementing the requirements of Section 6. 7 of the Diesel Vehicle 

Emission Inspection/Maintenance Program shall be: 

Permitting of an Official Diesel 1/M 

Program Fleet Station 

Annual Renewal of Station Permit 

Annual Renewal of Expired Station Permit 

Repermitting an 1/M Station at a New Location 

Clearing Mechanic Error Lockout(After 3rd/calender yr) 

Permitting an Official Diesel Opacity Inspector 

Annual Renewal of Inspector permit 

Annual Renewal of Expired Inspector permit 

Certificate of Compliance 

Duplicate Certificate of Compliance or Waiver 

Opacity Inspection Fee 

Opacity Reinspection Fee 

B-1 

$250.00 

25.00 

75.00 

50.00 

25.00 

20.00 

10.00 

30.00 

4.00 

5.00 

23.00 

10.00 

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APPENDIX C 

Diesel Opacity Inspection 

Equipment Specifications 

Effective Date: May 1, 1995 

C-1.0 General Requirements For The Smokemeter 

The Diesel opacity inspections require the use of a smoke measurement and 

data processing system which includes four functional units. These units may be 

integrated into a single component or provided as a system of interconnected 

components. The four functional units are: 

a) A partial flow type smokemeter meeting the minimum specifications of 

section C-1.1 of this APPENDIX and capable of performing smoke readings in 

accordance with the current version of SAE J1667 Technical Paper. 

b) A data processing unit capable of performing the functions described in 

Appendices A and C of J 1667 and meeting the requirements of the UTAH DIESEL 

1/M PROGRAM analyzer specifications. 

c) A printer and electronic storage medium to record and output the individual 

corrected average opacity values from each test cycle, and the final average 

opacity test result. 

d) A dedicated printer to print certificates of compliance when a vehicle meets 

all applicable requirements of these regulations. 

C-1.1 Smokemeter minimum specifications. 

* Automatically self-calibrates at zero and 1 00% before each set of snap 

tests and at regular intervals in continuous or rolling mode. 

*Has a warm-up time of less than ten (10) minutes. 

* Meets SAE and ISO specifications for measuring smoke opacity. 

*Has an adjustable response time from zero to 1400 MS (milliseconds). 

* Has a physical response time of less than 100 MS and stores values every 

10 MS in snap mode. 

*Can be powered by a 12 volt DC source. 

* Is controlled by a removable software program cartridge that is easily 

updated. 

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* Has a built-in printer that prints numerical or strip-chart type data. 

* Has enclosed heated measuring chamber of 1 00 MM to provide for 

consistent, accurate smoke measurement and to provide for self-cleaning of lenses. 

* Has built-in self diagnostics and failure code display for hardware and 

software problems. 

* Automatically prompts operator when cleaning is needed. 

* Provides for PC/Data communication or remote control operation and allows 

for vehicle specific data to be entered using 2 RS232 ports. 

* Provisions for engine RPM measurement. 

*Is equipped with sampling probe that does not require specificplacementin 

exhaust stack and is not affected by wind or rain. 

* Has a visual display of zero to 100 % opacity in 0.1 % increments accurate 

to .55%. 

* Can operate at ambient temperatures from 41° F - 110° F. 

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APPENDIX D 

Diesel Vehicle Opacity Inspection Procedures 

Effective Date: May 1, 1995 

Safety is a primary concern during any diesel opacity inspection. If there is a 

hazardous condition with the vehicle or the test equipment DO NOT BEGIN THE TEST. If 

the test is in progress DISCONTINUE THE TEST IMMEDIATELY. 

D-1.0 Light Duty Diesel Test Procedure 

D-1.1 Prior to performing the rolling-acceleration test the following items must be 

completed: 

(a) Drive the vehicle into the test lane centering it left to right on the dynamometer 

rollers. 

(b) Position the drive wheels on the lift plate between the rollers. 

(c) Lower the lift plate. 

(d) Position wheel chocks in front and behind of a non-drive wheel. 

(e) Walk around the vehicle looking for any hazardous conditions such as low tire 

pressure, studded tires, poor tire condition, fluid leaks, etc. Correct low tire pressure 

according to tire sidewall information. Abort inspection if more serious conditions exist. 

(f) The vehicle should be inspected for exhaust leaks. Severe leaks in the exhaust 

system must be repaired prior to performing the opacity inspection. 

(g) Check engine oil. If oil level is more than one quart low or more than one quart 

overfull do not test the vehicle. Inform vehicle owner of the condition. If the oil level is low 

and the owner has oil it may be added by the owner and the test may continue. Vehicles 

that are overfull must have the oil drained to a safe level before the inspection may 

continue. 

(h) Verify that all engine driven accessories are turned off. 

(i) Secure the vehicle for testing. Center the vehicle in the cradle by slowly spinning 

the drive wheels with no load applied. Automatic restraints may be used if available. If 

automatic restraints are not available the vehicle must be fastened down to the floor 

anchors. Rear wheel drive vehicles require one restraint to the rear frame rail or trailer 

hitch. Remove the slack from the chain, tension is not necessary. Front wheel drive 

vehicles require two restraints crossing each other. Attach to a front frame rail, bumper 

brackets or tow hooks, tension should be felt. 

D-1 
U) Position the auxiliary cooling fan in front of the vehicle 

air intake. 

directed at the radiator 

D-1.2 Enter the CONSTANT SPEED MODE on the dynamometer. Set the target speed at 

50 MPH. Set the target load at 30% of the engine's rated horsepower. 

D-1.3 Check to make sure that the vehicle is at operating temperature by looking at the 

temperature gauge or feeling the upper radiator hose. If the vehicle is not at operating 

temperature it may be run on the dynamometer with a light load until operating temperature 

is reached. 

D-1.4 Select the appropriate gear closest to direct drive, usually automatic transmissions 

will be "D" or "3" and manual transmissions will be 4th gear. Trucks with compound low 

should use 3rd gear. (gear selection may take some experimentation to get right). DO NOT 

TEST VEHICLE IN OVERDRIVE. Slowly accelerate vehicle to 50 MPH+ or- 2 MPH, begin 

applying the load. Continue accelerating until the actual load is the same as the target load 

entered during D-1.2 above. Allow speed and load to stabilize at the target values+ or5%. Note: On front wheel drive vehicles the steering wheel must be held firmly to 

avoid torque-steer problems. 

D-1.5 Record opacity when smoke readings stabilize or after 30 seconds of reaching speed 

and load stability, whichever comes first. If smoke readings are fluctuating record the 

highest readings. 

D-1.6 With the load still applied to the vehicle slowly push the accelerator pedal to the floor 

and hold it 15 seconds or until the smoke and horsepower readings again stabilize. NOTE: 

The dynamometer will hold the speed steady at 50 MPH +or- 5 MPH even with the vehicle 

at WOT. 

D-1. 7 After the readings have stabilized remove your foot from the accelerator pedal and let 

the vehicle speed coast down while gently applying brake pedal pressure. Bring the rollers 

to a complete stop before placing the transmission in park. 

NOTE: NEVER APPLY HARD BRAKING FORCE TO A VEHICLE THAT IS TURNING 

THE DYNAMOMETER ROLLS. THE INERTIA FROM THE ROLLS COULD CATAPULT 

THE VEHICLE OUT OF THE CRADLE. 

D-1.8 If either of the opacity readings obtained in D-1.5 or D-1.6 are above the maximum 

allowable standard for the vehicle as referenced in APPENDIX A perform D-1.2 through D1.6 two additional times and record the results. If the three readings obtained are within 

10% of each other then they should be averaged to determine pass/fail result. If the three 

readings are not within 10% of each other then the lowest reading should be used to 

determine pass/fail result. 

D-1.9 Vehicles with turbocharged engines require a three to five minute idle period after the 

WOT portion of the opacity inspection is complete. This allows the turbocharger to cool 

down. 

D-1.1 0 Remove the probe, fan, wheel chocks and restraints. Raise the lift. 

D-11 
t' D-1.11 If the opacity readings are equal to or less than the opacity standard for that 

particular vehicle as listed in APPENDIX A. The vehicle passes the opacity inspection and 

a certificate shall be issued. 

D-1.12 Vehicles with opacity readings above the maximum opacity cutpoint listed in 

APPENDIX A have failed the inspection and will not be given a certificate until repairs have 

been made to bring the opacity levels equal to or less than the maximum opacity cutpoint or 

they have met the waiver requirements. 

D-2.0 Heavy Duty Diesel Test Procedure 

D-2.1 Prior to conducting the snap-acceleration test the following items must be completed: 

(a) If the vehicle is equipped with a manual transmission, the transmission must be 

placed in neutral and the clutch must be released. 

If the vehicle is equipped with an automatic transmission, the transmission must be 

placed in the park position, if available, or otherwise in the neutral position. 

(b) Position wheel chocks in front and behind of a non-drive wheel. 

(c) If the engine is equipped with an engine brake, it must be deactivated during the 

snap-acceleration testing. 

(d) All devices installed on the engine or vehicle which alter the normal acceleration 

characteristics of the engine and have the effect of temporarily lowering snap-acceleration 

test results, or preventing the test from being successfully completed, shall be deactivated 

prior to testing. 

(e) Verify that all engine driven accessories are turned off. 

(f) Check the vehicle for any hazardous conditions such as unusual engine noise, 

fluid leaks, etc. Abort the inspection f any hazardous conditions exist. 

(g) The vehicle should be inspected for exhaust leaks. Severe leaks in the exhaust 

system must be repaired prior to performing the snap-acceleration test. 

(h) Verify the speed-limiting capability of the engine governor by slowly depressing the 

engine throttle and allow the engine speed to gradually increase toward its maximum 

governed high idle speed. As the engine speed increases, carefully note any visual or 

audible indications that the engine or vehicle may be of questionable integrity. If there a 

no indications of problems, allow the engine speed to increase to the point that it is possible 

to verify that the speed limiting capability of the governor is functioning. Should there be 

any indication that the speed limiting governor is not functioning, or that potential engine 

damage , or unsafe conditions for personnel or equipment may occur, the throttle should 

immediately be released and the snap-acceleration testing of the vehicle shall be aborted. 

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D-2.2 Smokemeter installation. The smokemeter and other test equipment used for snapacceleration tests shall meet the specifications outlined in APPENDIX C. The general 

installation and operational procedures specified by the manufacturer shall be followed 

when preparing to test a vehicle. 

D-2.3 A tachometer to measure the engine speed shall be installed and calibrated per the 

manufacturer's recommendations for all opacity tests performed at a self-certified fleet 

station. 

D-2.4 Prior to the test, the vehicle should be operated under load for at least 15 minutes to 

ensure that the engine is warmed-up or the vehicle's water and lor oil temperature gauges 

may be checked to verify that the engine is within its normal operating temperature range. 

D-2.5 Snap-acceleration cycle. With the vehicle engine warmed-up and at low idle speed: 

(a) The operator shall move the throttle to the fully open position as rapidly as 

possible. 

(b) The operator shall hold the throttle in the fully open position until the time the 

engine reaches its maximum governed speed, plus an additional1-4 seconds. 

(c) Upon completion of the 1-4 seconds with the engine at its maximum governed 

speed, the operator shall release the throttle and allow the engine to return to low idle 

speed. 

(d) Once the engine reaches its low idle speed, the operator shall allow the engine to 

remain at idle for a minimum of 5 seconds, but no longer than 45 seconds, before initiating 

the next snap-acceleration test cycle. 

(e) Steps (a) through (d) shall be repeated as necessary to complete the snapacceleration test cycles required to validate the test or until ten snap-acceleration test 

cycles have been completed, whichever comes first. 

D-2.6 If the opacity readings are equal to or less than the opacity standard for that 

particular vehicle as listed in APPENDIX A. The vehicle passes the opacity inspection and 

a certificate shall be issued. 

D-2.7 Vehicles with opacity readings above the maximum opacity cutpoint listed in 

APPENDIX A have failed the inspection and will not be given a certificate until repairs have 

been made to bring the opacity levels equal to or less than the maximum opacity cutpoint or 

they have met the waiver requirements. 

D-IV 

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Particulate Matter (PM) Exhaust Emissions Reductions from Heavy-duty Diesel 

Vehicle Inspection and Maintenance (liM) Programs in Utah 

(Davis, Salt Lake and Utah Counties) 

Utah Division of Air Quality 

December 10, 2003 

(Updated Aprilll, 2006 in Response to Comments from EPA Region VIII) 

Attachment 4 
TABLE OF CONTENTS 

1. Executive Summary ............................................................................................................. 3 

2. Background......................................................................................................................... 4 

2.1 Program Description .................................................................................................. 4 

3. Quantifying the Benefits of the Utah Diesel liM Program .................................................. 5 

3.1 Decrease in PM Exhaust Emissions in 2002... ......... .... ..... ..... ...... ... ... . .... .... ... ...... .... 5 

3.2 Programs Show a Decrease in the Percentage of Trucks Failing Tests Over Time ... 8 

4. Conclusions .......................................................................................................................... 8 

5. Recommendation .................................................................................................................. 8 

Appendix ................................................................................................................................ 9 

Al. Inventory Change for Salt Lake and Utah Counties, 2002 ............................... 9 

A2. Programs Show a Decrease in the Percentage of Trucks Failing the Tests Over.... 10 

a Number of Years 

A3. Opacity Test Procedures .................................................................... 11 

A4. Characteristics of PM Exhaust from Heavy-Duty Diesels ............................. 11 

Detailed Computations of Heavy-duty Diesel Vehicle PM Exhaust Reductions from ......... 13 

Opacity Testing 

Salt Lake County, Calendar Year 2002 .......................................................... 14 

Utah County, Calendar Year 2002 ................................................................ 18 

2 
1. Executive Summary 

This study shows that the Utah diesel I/M programs currently in place in Davis, Salt Lake and Utah 

Counties reduce PM exhaust. In 2002, the PM exhaust emissions reductions from the heavy-duty diesel 

IJM programs were estimated to be 3.56 % and 6.96% of the PM exhaust emissions inventory of heavyduty diesel vehicles (HDDV) in Salt Lake and Utah Counties respectively. The Utah Division of Air 

Quality is claiming a 2% reduction in PM exhaust emissions from on-road heavy-duty diesel vehicles 

from the diesel smoke opacity programs in its PMlO State Implementation Plan (SIP). To quantify PM 

exhaust emissions reductions, Utah used a methodology developed by Radian Corporation. 1 This study 

applies an "emissions reduction correction factor" to the repair of each malfunctioning component 

identified during smoke opacity testing. 

Notes: 

1. "Heavy-Duty Vehicle Inspection and Maintenance Final Report", Radian Corporation, May 1988. 

3 

2. Background 

Davis, Salt Lake, and Utah Counties began phase-in of the diesel Inspection and Maintenance (liM) 

Program on November 1, 1994. The program is a PMIO control measure included in the PMIO SIP (see 

Section IX.A.6). The PM10 SIP text references the SIP Section XXI, "Diesel Inspection and 

Maintenance Program", which states that the program was begun "for purposes of PM10 attainment". 

Salt Lake and Utah Counties are currently designated non-attainment for PM10. However, these areas 

are presently in attainment with the PMIO NAAQS, and the Utah Division of Air Quality has submitted 

a new PMIO SIP maintenance plan to demonstrate attainment. 

The Utah Diesel liM SIP Section XXI states that diesel engines contribute significantly to the ambient 

PMIO concentration along the Wasatch Front, primarily in Davis, Salt Lake, and Utah Counties. As a 

significant contributor to PM emissions, diesel vehicles must be maintained and operated in such a 

manner as to minimize these emissions. 

Implementation of a diesel liM program is perceived to be an issue of equity by the public. Owners of 

gasoline vehicles have been subject to mandatory liM programs in Davis, Salt Lake, and Utah Counties 

for a number of years. 

2.1 Program Description 

A description of the Utah diesel liM programs for heavy-duty diesel vehicles (HDDV s) and light-duty 

diesel vehicles and trucks (LDDV and LDDT) follows: 

• Diesel liM (opacity) programs in Davis, Salt Lake and Utah Counties were implemented on 

November 1, 1994. 

• Diesel programs in these counties required annual opacity testing of on-road diesel vehicles 

during calendar years 1994 through 2002. 

• Beginning July 1, 2003, diesel vehicles less than six years old (i.e., during calendar year 2003, 

model years 1998 through 2002) are allowed to undergo opacity testing on a biennial basis. 

Vehicle age is defined here as (calendar year- model year), or (CY- MY). 

• New model-year diesel vehicles are exempted from opacity testing (e.g., in calendar year 2003, 

model-year 2003 vehicles are exempt). 

• During calendar year 2002, diesel vehicles of model years 1968 through 2002 are required to 

undergo annual liM as before. 

• Weber County has never implemented opacity testing for diesel vehicles. 

• There is a mix of centralized and decentralized test-and-repair facilities in the three counties. 

• Farm trucks are exempt from testing. 

4 
• Vehicles that fail the retest are required to be repaired. For light-duty trucks, Salt Lake County 

requires $750 to be spent on repairs before a cost waiver is issued. In all three counties, heavyduty trucks must spend up to $1,500 on repairs before a cost waiver can be obtained. Vehicles 

which are not issued a cost waiver are denied vehicle registration. The vehicles are required to 

have emissions control devices present and in operating order, except in Utah County, where no 

tampering inspections are performed. 

• Davis and Utah Counties have a light-duty On-Board Diagnostics (OBD) program for 

Volkswagen diesel vehicles up to 8500 lbs GVWR. 

Light-Duty Diesel Vehicles 

The light-duty diesel liM program was not evaluated in this paper because DAQ could not find a 

quantitative analysis of PM exhaust emissions reductions from opacity testing of light-duty diesels. 

Heavy-Duty Vehicles 

Heavy-duty diesel vehicles (with a GVWR greater than 16,000 lbs are) tested using the SAE 11667 

"snap acceleration" test procedure. This is a test to measure an average of peak smoke levels and is a 

transient, not a steady-state measurement. The opacity cutpoint has been adjusted upwards to 

compensate for altitude as recommended in the Society of Automotive Engineers J-1667 procedure. 

Altitude compensation is required to minimize false failures during snap acceleration opacity testing. 

3. Quantifying the Benefits of the Utah Heavy-duty Diesel Vehicle Opacity Testing Programs 

Data from the Utah heavy-duty diesel vehicle liM programs and a statistical correlation developed by 

Radian Corporation were gathered and analyzed to substantiate the benefits of the Utah diesel opacity 

programs. 

3.1 Decrease in PM Exhaust Emissions in 2002 

By keeping records of the vehicles tested, the kinds of repairs, and conducting pre- and post-mass flow 

emission tests, a statistical correlation was developed by Radian that defines the change in the PM 

exhaust emissions inventory caused by the fraction of the HDDV fleet that fails an opacity test. The 

Radian study analyzes all potential component failures that cause vehicle smoke to increase and that can 

be identified by a smoke opacity program. There are only a very few engine component malfunctions 

that cause smoke to increase in diesel engines. The emission benefits associated with repair of these 

components are used to show the repair benefits of Utah's diesel programs. 

The calculation of PM exhaust emissions reductions for Utah is based on the failure rate for heavy-duty 

diesels greater than 16,000 pounds GVWR, the statistical correlation factor from the Radian study, and 

the current PM exhaust emissions inventory of on-road HDDVs in the three counties as calculated by the 

EPA PARTS emissions model. 

The Radian study evaluated a HDDV fleet for opacity and determined the fraction of vehicles failing by 

model year. Then they determined the engine problems associated with opacity increase that existed in 

each failing truck. Finally, emissions tests which measured the mass flow of pollutants were made 

5 
before and after repair of each engine failing the initial opacity test. Then percent change in mass flow 

emissions was calculated for pre- and post-engine repair conditions. A statistical correlation was 

computed that estimated PM exhaust emissions increases for failing vehicles by model year. 

The following calculations were developed to estimate the amount of PM exhaust emission benefits 

from the Utah heavy-duty diesel IIM program: 

Calculation 1. Heavy-Duty Control Factor 

Heavy-Duty Control Factor= 11 ( 1 + (FR * dTEML)) 

HDCF =the heavy-duty control factor. This fraction represents the decrease in current inventory 

associated with repairing HDDV s failing the opacity test to the point that they would pass the opacity test. 

FR = the failure rate for HDDV s in the testing program. Expressed as a fraction of heavy-duty diesels 

undergoing the opacity test, this data comes from county testing data in Utah. 

dTEML =the increase in emissions ofHDDVs that fail the smoke opacity test compared to emissions of 

HDDV s that pass the smoke opacity test. Radian calculated this number from the change in mass flow of 

emissions from before and after repair of an engine that failed the opacity test. It is inserted into the 

equation as a decimal, not as a percent. 

Calculation 2. Inventory in tons per day 

Fadj = Favg *(%targeted* a* b * (HDCF- 1) + 1) where 

Fadj = the inventory in tons per day associated with repairing HDDV s to the point that they would pass 

the opacity test. This is the equation referred to as the statistical correlation in the text of this paper. 

Favg = the total current inventory (before test and repair) of the HDDV fleet in an air shed or an area to 

be evaluated. This was calculated using the EPA PARTS emissions model. 

%targeted= the percent ofHDDVs that are tested by the program. Since the county ordinances for areas 

with the diesel inspection and maintenance program require diesel vehicles to pass the opacity test to 

obtain renewal of their registration, this value is 100% in calendar year 2002, when annual testing was 

still required of all model years. 

"a"= the adjustment factor that describes the fraction of a year for which the test is considered valid. 

Since the test is valid for the whole year, the value should be 100%. 

"b" = the percent of vehicles repaired. All vehicles subject to the diesel inspection and maintenance 

programs must pass the opacity test to have their registration renewed. The value of this parameter is 

100% since no vehicle may drive without registration. 

Tables 1 and 2 show the data for the HDDV smoke opacity tests performed in Salt Lake and Utah 

Counties, respectively, in calendar year 2002. 

6 
Table 1. Data for Smoke Opacity Tests on HDDVs, Salt Lake County, UT 

Calendar Year 2002-SAL T LAKE COUNTY 

Year Number Tested* Number Failed* Percent Failed* dTEML** 

1968- 1984 766 43 5.61% 322.88% 

1985- 1987 555 26 4.68% 333.00% 

1988-2002 10,722 96 0.90% 253.51% 

TOTAL 12,043 165 

TRUCKS 

*The number of vehicles tested, failed and repaired in the above table includes HDDVs only. 

**The variable "dTEML" is the increase in emissions ofHDDVs that fail the smoke opacity test 

compared to emissions of HDDV s that pass the smoke opacity test. This value is different for each 

model-year group ofHDDVs. 

An abbreviated calculation for Salt Lake County, 2002 is shown in Appendix Al. For Salt Lake 

County, the 2002 heavy-duty diesel vehicle PM exhaust is 0.6008 tons per day of PM exhaust with 

smoking diesels tested and repaired. Compared to the pre-test-and-repair inventory of 0.6230 tons per 

day of PM exhaust, this represents a reduction of 3.56%. 

Table 2. Data for Smoke Opacity Tests on HDDVs, Utah County, UT 

Calendar Year 2002--UT AH COUNTY 

Year Number tested Number failed Percent failed dTEML 

1968- 1984 409 27 6.60% 322.88% 

1985- 1987 228 16 7.02% 333.00% 

1988-2002 1,992 28 1.41% 253.51% 

TOTAL 2,629 71 

TRUCKS 

An abbreviated calculation for Utah County, 2002 is shown in Appendix Al. For Utah County, the 

2002 heavy-duty diesel vehicle PM exhaust inventory is 0.2140 tons per day of PM with smoking 

diesels repaired and compared to the pre-test-and-repair inventory of 0.2300 tons per day of PM exhaust. 

This represents a reduction of 6.96 %. 

7 
Table 3: PM Exhaust Reductions from Opacity Program as Percent of 

On-Road Heavy-duty Diesel Vehicle PM Exhaust Inventory by County 

County PM Exhaust Reductions from 

Opacity Program as Percent 

of On-road HDDV PM 

Exhaust Inventory in each 

County(%) 

2002 

Salt Lake 3.56% 

Utah 6.96% 

3.2 Programs Show a Decrease in the Percentage of Trucks Failing Tests over Time 

Failure rates decrease very rapidly in the early years of the program. In later years, the percentage of 

failing vehicles falls more slowly. Programs in other areas of the United States show a similar trend. 

Failure rates from the Utah programs are found in Appendix A2 (pp. 10 and 11). 

In years when annual testing is required, the value of"% targeted" is 100%. Beginning January 1, 2004, 

all HDDVs are required to undergo biennial testing. The value of"% targeted" for these years will be 

50%. A decrease in the value of"% targeted" causes the magnitude of PM exhaust reductions to 

decrease. In addition, lower failure rates, which are expected in future years, will also cause the 

magnitude of PM exhaust reductions to decrease. 

4. Conclusions 

1. In calendar year 2002, opacity testing programs in Salt Lake and Utah Counties reduced PM 

exhaust emissions by approximately 3.56% and 6.96% of on-road heavy-duty diesel emissions, 

respectively. 

2. Opacity test results show a large decrease in the percent of vehicles failing the test over a number 

of years with most of the decrease in the early years. 

3. Both proper maintenance of diesel vehicles and periodic smoke opacity testing and inspection 

are important in minimizing air pollution from these sources. 

5. Recommendation 

The Utah Division of Air Quality is claiming a 2% credit for its on-road heavy-duty diesel opacity 

programs in the PMlO SIP Maintenance Plan. PM exhaust emissions reductions from the Salt Lake 

and Utah County opacity testing programs were estimated to be 3.56 % and 6.96%, respectively, for 

on-road heavy-duty diesels. If the program is discontinued, it is very likely that maintenance on 

heavy-duty diesel engines will decrease and emissions will increase. 

8 
APPENDIX 

Al. Inventory Change for Salt Lake and Utah County, 2002 

Salt Lake County: 

Heavy-Duty Control Factor= 11(1 + (FR*dTEML)) 

Heavy-Duty Control Factor= 11(1+(0.0561 *3.2288)) where 0.0561 is the failure rate for the 1968- 1984 

model year heavy duty diesel trucks and 3.2288 is the change in emissions level from the Radian study. 

Heavy-Duty Control Factor= 0.8466 for 1968- 1984 model years 

Heavy-Duty Control Factor= 0.8652 for 1985- 1987 model years 

Heavy-Duty Control Factor= 0.9777 for 1988-2002 model years 

A weighted average by number of vehicles makes the overall HDCF = 0.9643 

Fadj = Favg *(%targeted* a* b * (HDCF- 1) + 1) 

where Favg =heavy-duty diesel vehicle inventory of PM exhaust before test and repair and 

Fadj =heavy-duty diesel vehicle inventory of PM exhaust after test and repair. 

Fadj = 0.6230 * (1.00*1.00*1.00*(0.9643- 1) + 1) where 0.6230 tons per day is the PM exhaust from the 

heavy-duty diesel vehicle fleet for 2002 before test and repair 

Fadj = 0.6008 tons PM per day= PM exhaust from the HDDV fleet for 2002 after test and repair 

The percent reduction in the heavy-duty diesel vehicle PM exhaust inventory due to test and repair of 

these vehicles is the following: 

Percent reduction (PM exhaust)= [(Favg- Fadj)/Favg]* 100% = 

[(0.6230- 0.6008)/0.6230]* 100% = (0.0222/0.6230)* 100% = 3.56% 

Utah County: 

Heavy-Duty Control Factor= ll(l+(FR*dTEML)) 

Heavy-Duty Control Factor= 11(1+(0.0660*3.2288)) where 0.0660 is the failure rate for the 1968- 1984 

model year heavy duty diesel trucks and 3.2288 is the change in emissions level from the Radian study. 

Heavy-Duty Control Factor= 0.8243 for 1968- 1984 model years 

Heavy-Duty Control Factor= 0.8105 for 1985- 1987 model years 

Heavy-Duty Control Factor= 0.9655 for 1988- 2002 model years 

A weighted average by number of vehicles makes the overall HDCF = 0.9289 

Fadj = Favg *(%targeted* a* b * (HDCF- 1) + 1) 

9 
Fadj = 0.2300* (1.00* 1.00* 1.00*(0.9289- 1) + 1) 

where 0.2300 tons per day is the PM exhaust from the IIDDV fleet for 2002 before test and repair and 

Fadj = 0.2140 tons per day PM exhaust= PM exhaust emissions from IIDDV fleet for 2002 after test and 

repair. 

The percent reduction in the heavy-duty diesel vehicle PM exhaust inventory due to test and repair of 

these vehicles is the following: 

Percent reduction (PM exhaust)= [(Favg- Fadj)/Favg]* 100% = 

[ (0.2300 - 0.2140)/0.2300] * 100% = (0.0 160/0.2300)* 100% = 6. 96 % 

A2. Programs Show a Decrease in the Percentage of Trucks Failing the Tests Over a Number of 

Years: 

(Heavy-Duty Diesel Vehicles) 

Calendar Years Number of Vehicles Failure Rates 

Tested (%) 

Utah County 1995 402 14.4% 

Utah County 1996 2,441 13.6% 

Utah County 1997 2,528 7.9% II 1998 2,264 5.6% II 1999 2,075 5.7% II 2000 2,447 4.5% II 2001 2,516 2.2% II 2002 2,629 2.7% 

Salt Lake Co 1997 8,722 4.70% 

Salt Lake Co 1998 10,383 2.86% II 1999 10,142 2.28% II 2000 11,896 1.70% II 2001 12,461 1.65% II 2002 17,043 1.37% 

10 
A3. Opacity Test Procedures 

Heavy-Duty Diesel Vehicle SAE J1667 Snap-Acceleration Program 

J1667 requires, with the transmission in neutral and the engine at normal (low) idle, the accelerator 

pedal to be depressed to the maximum, or wide open throttle, position. The pedal is held at this position 

for five seconds or until the engine reaches maximum (governed) speed, whichever occurs first. The 

pedal is then released to allow the engine to return to normal idle. Typically, peak smoke opacity, rather 

than average smoke opacity, is measured during this test. This test cycle forms the basis of the SAE 

J1667 test. During the "snap-acceleration" test, smoke emissions can be emitted as a relatively short 

duration puff of smoke, and the response time of the instrument used to measure the opacity of the puff 

has a major effect on the measured value of peak smoke opacity. The most significant difference 

between the J1667 procedure and the procedure employed previously by CARB--the SAE J1243 test--is 

in the instrument response time specifications. The SAE J1667 procedure differs in several key respects 

from the earlier J1243 procedure, specifically because it is the recommended procedure for assessing 

smoke emissions from in-use vehicles powered by diesel engines. The SAE J1667 incorporates: 

• A specific method for performing the snap acceleration test; 

• Correction factors for normalizing measured smoke opacity when measurements are made at 

alternative optical path lengths and non-standard ambient conditions; 

• Specifications for the smoke meter, and especially for overall instrument response time; and 

• Correction factors for altitude. 

Three snap tests are made with the best two test results averaged. 

System/Dynamometer Setup 

The system must display the appropriate horsepower loading for the dynamometer. The system will 

obtain the horsepower rating information from the Horsepower Lookup Table. Manufacturers' specified 

procedures shall be followed when setting up or attaching equipment and instrumentation. 

A4. Characteristics of PM Exhaust from Diesels 

Most diesel emissions particles are in the fine (less than 2.5 micron) and ultra-fine (less than 0.1 micron) 

range for the newest diesels in good mechanical order.2 

Notes: 

2. Environmental Protection Agency, Office of Air and Radiation, "Regulatory Impact Analysis, Chapter II: Health and 

Welfare Concerns and Emissions Benefits (EPA420-R-00-026) for the Final Rule, Control of Air Pollution from New Motor 

Vehicles: Heavy-Duty Engine and Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements", January 18, 

2001. 

11 
West Virginia University Alternative Vehicle Program's findings are presented below: 

"The difference between black smoke and colorless smoke is likely to be that black smoke 

contains larger elemental carbon particles or indicates a heavier loading of PM, whereas, 

"colorless" smoke simply indicates a low loading of PM or the presence of acid droplets and 

hydrocarbons. "

3 

Notes: 

3. Private correspondence with West Virginia University, 10/9/2003. 

12 
DETAILED COMPUTATIONS OF HEAVY-DUTY DIESEL VEHICLE PM 

EXHAUST REDUCTIONS FROM OPACITY TESTING 

Salt Lake County, Calendar Year 2002 

Utah County, Calendar Year 2002 

13 

COMPUTATION OF PM EXHAUST REDUCTION FROM OPACITY TESTING OF HDDVs 

SALT LAKE COUNTY 

Nov. 28, 2003, rev. March 24, 

2006 

Method from Radian study, "Heavy-Duty Diesel Vehicle Inspection and Maintenance Study, Final 

Report", May 1988. 

1. Compute average failure rate of opacity test 

Calendar Year 2002--SALT LAKE COUNTY 

Vehicle 

Weight No of 

Class and Vehicles 

Model Years 

1968-1984 766 

HHDDV 436 

MHDDV 186 

LHDDV 144 

SUBT 766 

1985-1987 555 

HHDDV 316 

MHDDV 135 

LHDDV 104 

SUBT 555 

1988-2003 10722 

HHDDV 6100 

MHDDV 2609 

LHDDV 2012 

SUBT 10722 

TOTAL NO 12043 

OF TRUCKS 

No of Failed 

Vehicles 

43 

24 

10 

8 

43 

26 

15 

6 

5 

26 

96 

55 

23 

18 

96 

165 

%Failed 

5.61% 

5.61% 

5.61% 

5.61% 

4.68% 

4.68% 

4.68% 

4.68% 

0.90% 

0.90% 

0.90% 

0.90% 

1.37% 

Vehicle Type 

Mix Fractions* 

*depends on 

county 

and calendar year 

0.5690 

0.2434 

0.1877 

1.0000 

0.5690 

0.2434 

0.1877 

1.0000 

0.5690 

0.2434 

0.1877 

1.0000 

HHDDV= heavy heavy-duty diesel vehicle (> 33,000 lbs GVWR) 

MHDDV= medium heavy-duty diesel vehicle (>19,500- 33,000 lbs GVWR) 

LHDDV = light heavy-duty diesel vehicle(< 19,500 lbs GVWR) 

2. Find value of dTEML (from Radian Study) 

Let dTEML =change in total emissions level of PM exhaust 

14 
The Radian study quantified emissions due to component malfunctions of heavy-duty diesel vehicles. 

The effect of each type of component malfunction on fleet-average emissions is calculated by multiplying 

the frequency of each malfunction in the fleet by its effect on emissions from heavy-duty diesel vehicles 

in which a malfunction occurs. 

Model-year Specific Change in Emissions Level for HDDVs that Fail Opacity Test 

Radian determined that the increase in emissions of PM exhaust due to malfunctions of components 

were the following. The increases were estimated for 3 model-year groups as follows: 

PM 

No of Trucks 

1968-1984 

Ofo 

322.88 

766 

1985- 1987 

o/o 

330.00 

555 

1988 -2003 

o;o 

253.51 

10722 

3. Compute emissions inventory of PM exhaust from HDDVs using the EPA PART5 mobile emissions 

model: 

SL County 

2002 

Arterial 

Fwy & Ramp 

Local 

SUM 

SL County 

2002 

Arterial 

Fwy & Ramp 

Local 

SL County 

2002 

Arterial 

Fwy & Ramp 

Local 

SUM 

(winter 

weekday Vehicle Type 

traffic) Mix Fractions 

2BHDDV LHDDV 

10,674,026 0.0096 0.0000 

7,833,275 0.0146 0.0000 

2,691,536 0.0004 0.0000 

21,198,837 

Emission Factors 

2BHDDV LHDDV 

0.147 0.000 

0.147 0.000 

0.147 0.000 

PM Exhaust Emissions (tons per winter weekday) 

2BHDDV LHDDV MHDDV 

0.0166 0.0000 0.0756 

0.0185 0.0000 0.0850 

0.0002 0.0000 0.0008 

4. Find values of HDCF, the heavy-duty control factors: 

MHDDV 

0.0124 

0.0190 

0.0005 

MHDDV 

0.518 

0.518 

0.518 

HHDDV 

0.1880 

0.2108 

0.0019 

HHDDV 

0.0269 

0.0411 

0.0011 

HHDDV 

0.594 

0.594 

0.594 

BUSES 

0.0118 

0.0136 

0.0001 

BUSES 

0.0021 

0.0033 

0.0001 

BUSES 

0.479 

0.479 

0.479 

SUM 

0.2920 

0.3280 

0.0030 

0.6230 

The Radian study defines HDCF as the "heavy-duty control factor". These factors are used to recalculate the 

emissions inventory after test and repair. 

Values of HDCF by Model Year Group 

Weight 

Class 1968-1984 1985-1987 1988-2003 

15 
HHDDV 

MHDDV 

LHDDV 

0.8466 

0.8466 

0.8466 

0.8661 

0.8661 

0.8661 

Compute values of HDCF by vehicle weight class: 

Weight 

Class 

HHDDV 

MHDDV 

LHDDV 

HDCF by 

Wt Class 

0.9643 

0.9643 

0.9643 

0.9778 

0.9778 

0.9778 

In the Radian study, only three groups of heavy-duty diesel vehicles were used, whereas in PARTS, five 

groups are used. Condense the five groups used in PARTS to the three groups used in the Radian study. 

PARTS 

Groups 

2BHDDV and LHDDV 

MHDDV 

HHDDV and BUSES 

Radian Groups 

LHDDV 

MHDDV 

HHDDV 

Thus the values of HDCF for each of the five vehicle groups in PARTS are as follows: 

2002 2BHDDV LHDDV MHDDV HHDDV BUSES 

HDCFs 0.9643 0.9643 0.9643 0.9643 0.9643 

S. Compute adjusted inventory accounting for emissions reductions from opacity program: 

Let "Favg" =the inventory of PM exhaust from HDDV in tons per day before test and repair. 

Let "Fadj" =the inventory of PM exhaust from HDDVs in tons per day after repair to the point 

where they pass the opacity test: 

Thus Fadj = Favg * (% targeted * a * b * (H DCF -1) + 1) where "% targeted" = 1.00 or 1 00%; "a" = 1.00 

and "b" = 

1.00: 

The values of"% targeted", a and bare each 1.000; therefore, simply multiply the emissions inventory 

Computed in step 3 above by the value of HDCF to obtain the new inventory after test and repair of HDDVs. 

Adjusted Inventory of PM10 Exhaust Emissions (HDDV only) After Test and Repair 

PM PM Exhaust PM PM Exhaust PM PM 

2002 Exhaust Emissions Exhaust Emissions Exhaust Exhaust 

Emissions Emissions Emissions Emissions 

(tons per (tons per winter (tons per (tons per winter (tons per (tons per 

SL County winter weekday) winter weekday) winter winter 

weekday) weekday) weekday) weekday) 

2BHDDV LHDDV MHDDV HHDDV BUSES SUM 

Arterial 0.0160 0.0000 0.0729 0.1813 0.0114 0.2816 

Fwy& Ramp 0.0179 0.0000 0.0820 0.2033 0.0132 0.3163 

Local 0.0002 0.0000 0.0007 0.0019 0.0001 0.0029 

0.6008 

6. Compute the PM exhaust emissions reductions from the opacity testing program: 

16 

: 

j 

I 

I 

I 

I 

I I I 

I 

I 

t 

f. 

i 

l 

f 
PM PM Exhaust PM PM Exhaust PM PM 

2002 Exhaust Emissions Exhaust Emissions Exhaust Exhaust 

Emissions Reductions Emissions Reductions Emissions Emissions 

Reductions Reductions Reductions Reductions 

(tons per (tons per winter (tons per (tons per winter (tons per (tons per 

SL County winter winter winter winter 

weekday) weekday) weekday) weekday) weekday) weekday) 

2BHDDV LHDDV MHDDV HHDDV BUSES SUM 

Arterial 0.0006 0.0000 0.0027 0.0067 0.0004 0.0104 

Fwy & Ramp 0.0007 0.0000 0.0030 0.0075 0.0005 0.0117 

Local 0.0000 0.0000 0.0000 0.0001 0.0000 0.0001 

0.0222 

7. Compute the PM exhaust emissions reductions from the opacity testing program (in percent): 

(for HDDVs only) = 

2002 3.57% 

Salt Lake Co 

RECALCULATION OF THE ADJUSTED INVENTORY (i.e., the post-repair inventory of HDDVs only) 

USING A VALUE OF 96% FOR"% TARGETED": 

The liM program managers report an estimated compliance rate of 96%, which is a more conservative value 

for the variable "% targeted". 

Let "Fadj" =the inventory of PM1 0 exhaust from HDDVs in tons per day after test and repair. 

Thus Fadj = Favg * (%targeted * a * b * (HDCF -1) + 1) where "%targeted" = 0.96 or 96%; "a" = 1.00 and "b" 

= 1.00: 

Fadj =initial PM10 exhaust inventory of HDDVs * (% targeted*a*b*[HDCF- 1] + 1) where 

% targeted = 0.96 or 96%, the compliance rate; and a and b = 1.00 each. 

Fadj = (0.623 tons per day) * (0.96*1.00*1.00*(0.9643 -1) + 1) 0.6016 

tons per winter 

weekday 

8. Compute the PM exhaust emissions reductions from HDDV opacity testing program at a compliance rate 

of 96%: 

2002 

Salt Lake County = (0.6230- 0.6016)/0.6230 = (0.0214/0.6230) = 0.0343 = 3.43% 

17 
COMPUTATION OF PM EXHAUST REDUCTION FROM OPACITY TESTING 

UTAH COUNTY 

Dec. 3, 2003, revised Mar 24,2006 

Method from Radian study, "Heavy-Duty Diesel Vehicle Inspection and Maintenance Study, Final 

Report", May 1988. 

1. Compute average failure rate of opacity test 

Calendar Year 2002--UTAH COUNTY 

Vehicle Weight 

Class and Model 

Years 

1968- 1984 

HHDDV 

MHDDV 

LHDDV 

SUBT 

1985- 1987 

HHDDV 

MHDDV 

LHDDV 

SUBT 

1988-2003 

HHDDV 

MHDDV 

LHDDV 

SUBT 

TOTAL NO 

OF TRUCKS 

No of 

Vehicles 

409 

233 

100 

77 

409 

228 

130 

56 

43 

228 

1992 

1134 

485 

373 

1992 

2629 

No of 

Failed 

Vehicles 

27 

15 

7 

5 

27 

16 

9 

4 

3 

16 

28 

16 

7 

5 

28 

71 

%Failed 

6.60% 

6.60% 

6.60% 

6.60% 

7.02% 

7.02% 

7.02% 

7.02% 

1.41% 

1.41% 

1.41% 

1.41% 

Vehicle Type 

Mix Fractions* 

*depends on county 

and calendar year 

0.5691 

0.2435 

0.1874 

1.0000 

0.5691 

0.2435 

0.1874 

1.0000 

0.5691 

0.2435 

0.1874 

1.0000 

HHDDV = 

MHDDV= 

LHDDV = 

heavy heavy-duty diesel vehicle (> 33,000 lbs GVWR) 

medium heavy-duty diesel vehicle (>19,500- 33,000 lbs GVWR) 

light heavy-duty diesel vehicle(< 19,500 lbs GVWR) 

2. Find value of dTEML (from Radian Study) 

Let dTEML = change in total emissions level of PM exhaust 

The Radian study quantified emissions due to component malfunctions of heavy-duty diesel vehicles. 

18 
The effect of each type of component malfunction on fleet-average emissions is calculated by multiplying 

the frequency of each malfunction in the fleet by its effect on emissions from heavy-duty diesel vehicles 

in which a malfunction occurs. 

Model-year Specific Change in Emissions Level for HDDVs that Fail Opacity Test 

Radian determined that the increase in emissions of PM exhaust due to malfunctions of components 

were the following. The increases were estimated for 3 model-year groups as follows: 

PM 

No of Trucks 

1968-1984 

% 

322.88 

409 

1985-

1987 

o/o 

330.00 

228 

1988-

2003 

% 

253.51 

1992 

3. Compute emissions inventory of PM exhaust from HDDVs using the EPA PART5 mobile emissions 

model: 

(winter 

UT County weekday Vehicle Type Mix Fractions 

traffic) 

2002 2BHDDV LHDDV MHDDV HHDDV BUSES 

Arterial 3,914,204 0.0094 0.0000 0.0122 0.0264 0.0021 

Fwy& Ramp 2,942,674 0.0146 0.0000 0.0190 0.0411 0.0033 

Local 1,424,522 0.0004 0.0000 0.0005 0.0011 0.0001 

SUM 8,281,400 

UT County Emission Factors 

2002 2BHDDV LHDDV MHDDV HHDDV BUSES 

Arterial 0.147 0.000 0.518 0.594 0.479 

Fwy & Ramp 0.147 0.000 0.518 0.594 0.479 

Local 0.147 0.000 0.518 0.594 0.479 

UT County PM Exhaust Emissions (tons per winter weekday) 

2002 2BHDDV LHDDV MHDDV HHDDV BUSES SUM 

Arterial 0.0060 0.0000 0.0273 0.0677 0.0043 0.1052 

Fwy & Ramp 0.0070 0.0000 0.0319 0.0792 0.0051 0.1232 

Local 0.0001 0.0000 0.0004 0.0010 0.0001 0.0016 

SUM 0.2300 

4. Find values of HDCF, the heavy-duty control factors: 

The Radian study defines HDCF as the "heavy-duty control factor". This factor is used to recalculate the 

emissions inventory after test and repair. 

Values of HDCF by Model Year Group 

Weight Class 

HHDDV 

1968-1984 

0.8243 

1985-1987 

0.8120 

1988-2003 

0.9656 

19 
MHDDV 

LHDDV 

0.8243 

0.8243 

0.8120 

0.8120 

Compute values of HDCF by vehicle weight class: 

Weight Class 

HHDDV 

MHDDV 

LHDDV 

HDCF by 

Wt Class 

0.9303 

0.9303 

0.9303 

0.96S6 

0.96S6 

In the Radian study, only three groups of heavy-duty diesel vehicles were used, whereas in PARTS, five 

groups are used. Condense the five groups used in PARTS to the three groups used in the Radian study. 

PARTS Groups 

2BHDDV and LHDDV 

MHDDV 

HHDDV and BUSES 

Radian Groups 

LHDDV 

MHDDV 

HHDDV 

Thus the values of HDCF for each of the five vehicle groups in PARTS are as follows: 

2002 2BHDDV LHDDV MHDDV HHDDV BUSES 

HDCFs 0.9303 0.9303 0.9303 0.9303 0.9303 

S. Compute adjusted inventory accounting for emissions reductions from opacity program: 

Let "Favg" =the inventory of PM exhaust from HDDV in tons per day before test and repair. 

Let "Fadj" =the inventory of PM1 0 exhaust from HDDVs in tons per day after repair to the point 

where they pass the opacity test: 

Thus Fadj = Favg * (% targeted * a * b * (HDCF -1) + 1) where "% targeted" = 1.00 or 1 00%; "a" = 1.00 

and "b" = 1.00: 

The values of"% targeted", a and bare each 1.000; therefore, simply multiply the emissions inventory 

computed in step 3 above by the value of HDCF to obtain the new inventory after test and repair of HDDVs. 

Adjusted Inventory of PM Exhaust Emissions (HDDV only) After Test and Repair 

PM PM PM PM Exhaust PM PM 

2002 Exhaust Exhaust Exhaust Emissions Exhaust Exhaust 

Emissions Emissions Emissions Emissions Emissions 

(tons per (tons per (tons per (tons per winter (tons per (tons per 

UT County winter winter winter winter winter 

weekday) weekday) weekday) weekday) weekday) weekday) 

2BHDDV LHDDV MHDDV HHDDV BUSES SUM 

Arterial o.ooss 0.0000 0.02S4 0.0629 0.0040 0.0979 

Fwy& Ramp 0.006S 0.0000 0.0297 0.0737 0.0048 0.1146 

Local 0.0001 0.0000 0.0004 0.0010 0.0001 0.001S 

0.2140 

6. Compute the PM exhaust emissions reductions from the opacity testing program: 

20 
PM PM PM PM Exhaust PM PM 

Exhaust Exhaust Exhaust Exhaust Exhaust 2002 Emissions Emissions Emissions Emissions Emissions Emissions 

Reductions Reductions Reductions Reductions Reductions Reductions 

(tons per (tons per (tons per (tons per (tons per 

winter winter winter (tons per winter winter winter 

UT County weekday) weekday) weekday) weekday) weekday) weekday) 

2BHDDV LHDDV MHDDV HHDDV BUSES SUM 

Arterial 0.0004 0.0000 0.0019 0.0047 0.0003 0.0073 

Fwy & Ramp 0.0005 0.0000 0.0022 0.0055 0.0004 0.0086 

Local 0.0000 0.0000 0.0000 0.0001 0.0000 0.0001 

0.0160 

7. Compute the PM exhaust emissions reductions from the opacity testing program (in percent): 

(for HDDVs only) = 

2002 6.97% 

Utah County 

RECALCULATION OF THE ADJUSTED INVENTORY (i.e., the post-repair inventory of HDDVs only) 

USING A VALUE OF 96% FOR"% TARGETED": 

The 1/M program managers report an estimated compliance rate of 96%, which is a more conservative value 

for the variable "%targeted". 

Let "Fadj" =the inventory of PM1 0 exhaust from HDDVs in tons per day after test and repair. 

Thus Fadj = Favg * (%targeted * a * b * (HDCF -1) + 1) where "%targeted" = 0.96 or 96%; "a" = 1.00 and "b" 

= 1.00: 

Fadj =initial PM10 exhaust inventory of HDDVs * (% targeted*a*b*[HDCF- 1] + 1) where 

%targeted= 0.96 or 96%, the compliance rate; and a and b = 1.00 each. 

Fadj = (0.230 tons per day) * (0.96*1.00*1.00*(0.9303 -1) + 1) 0.2146 

tons per winter 

weekday 

8. Compute the PM exhaust emissions reductions from HDDV opacity testing program at a compliance rate 

of 96%: 

2002 

Utah County = (0.2300 - 0.2146)/0.2300 = (0.0154/0.2300) = 0.0670 = 6.70% 

21 
• • 

Utah Division of Air Quality Response to EPA's Comments on Utah's "Particulate Matter 

(PM) Exhaust Emissions Reductions from Diesel Inspection and Maintenance (1/M) 

Programs in Utah (Davis, Salt Lake and Utah Counties)"- January 20, 2005 

Numbers indicate the paragraphs in EPA's comments where the questions were raised. 

1, 2, 3. EPA believes that we are not meeting the requirements of the Voluntary Mobile 

Source Emissions Reduction Programs (VMEP). 

Response: 

a. DAQ is not requesting EPA to approve the diesel opacity testing program as a VMEP 

control measure for the PMJO SIP. DAQ is requesting EPA to approve a two percent 

reduction in on-road heavy-duty diesel vehicle PM 10 exhaust emissions, which is a small 

reduction. If EPA approves the emission credit (i.e., the two percent reduction in HDDV 

PM10 emissions), DAQ will be able to maintain an important control measure, in support of 

the newly proposed PM2.5 standards. The state would be disinclined to continue diesel liM 

programs if there is no SIP credit. Without the opacity programs, on-road diesel vehicles 

would essentially be unregulated. This is not the message that DAQ wishes to convey to the 

trucking industry and the public. 

4. EPA believes that the use of MOBILE6 inherently grants diesel 1/M emissions credit 

because PMlO EFs from this model do not account for deterioration effects (i.e., the model 

assigns the same EFs to older vehicles as new ones). 

Response: 

At the beginning of the PM10 SIP process, MOBILE6 did not include the ability to compute 

emission factors for PM. PAR T5 was used to model PM and S02 emissions. 

5. EPA questions the correlation between PMlO emissions and opacity readings. EPA 

requests clarification of the meaning of the variable "dTEML". 

Response: 

a. DAQ is aware that the literature shows that the correlation between opacity and PM is low. 

However, Radian Corporation, the author of the original study, has published an update to its 

report of 1987 showing stronger correlations. See attachment, "Multiple Smoke Opacity 

Measurements as Indicators of Particulate Emissions for Heavy-Duty Diesel Vehicle 

Inspection and Maintenance Program". (approximately 2001) 

b. The variable "dTEML" is now clearly defined in the report. 

Attachment 5 
6. EPA requires that increases in other criteria pollutants, such as NOx, must be discussed 

and quantified. 

Response: 

The October 1997 TSD which contains amendments to the California HDVIP and smoke 

inspection program shows a negligible increase in NOx emissions for most of the repairs that 

reduce PM. See attachment (Tables 7-1, 7-2 and 7-3). Also, see the attached letter from 

Radian to Mark Carlock from 10/23/03. 

7. EPA states that DAQ's report applies to repaired vehicles only, or only [to] failed 

vehicles. DAQ will need to apply the findings of this report to the entire fleet of diesel 

vehicles, both light-duty and heavy-duty. 

Response: 

The opacity I/M programs in Davis, Salt Lake and Utah Counties require all on-road diesel 

vehicles to undergo opacity testing-this includes light-duty diesel passenger vehicles and 

trucks and heavy-duty diesel vehicles (HDDVs). 

However, the goal of the original Radian Corporation report was to estimate PM 10 exhaust 

emissions reductions from HDDVs only. This approach is consistent with the Radian study, 

because its study does not address how to estimate PMlO emissions reductions from lightduty diesel vehicles and trucks. 

DAQ has not found any methodology or existing studies that can be applied to estimate 

PMlO emissions reductions from light-duty diesel vehicles. Our computations were limited 

to PMlO emissions reductions from HDDVs only. 

8. EPA states that bullets 1 and 3 ( p.4 of the opacity report) are contradictory. In addition, 

EPA asks whether HDDVs undergo both OBD and opacity testing. Or are opacity tests 

performed only when the MIL light comes on? 

Response: 

a. Corrected in report. 

b. HDDVs undergo opacity testing only. In future years, the counties may implement OBD 

testing ofHDDVs. 

9. EPA requests that we verify the values ofthe variables "%targeted", "a" and "b". 

Response: 

a. These variables are defined in the report. 

10. EPA states that the reported values of the variable "HDCF" are incorrect. EPA asks 

whether the values of HDCF change in subsequent years. EPA asks for clarification of the 

2 
. 

• 

paragraph under Table 1 of the report. EPA asks whether the variable HDCF and the 

numbers of vehicles tested and failed apply to HDDVs only. 

Response: 

a. DAQ believes that its calculated values ofHDCF are correct (to at least three significant 

figures). 

Response: (continued) 

b. DAQ agrees that the values ofHDCF are not the same in subsequent calendar years (e.g., 

2003 -on). The values ofHDCF depend on the failure rate of each model-year group of 

HDDVs. DAQ expects the failure rate for opacity tests to decrease in subsequent years. This 

in turn causes the value ofHDCF to increase, which causes estimated PMlO exhaust 

emissions reductions to decrease. 

c. In addition, the value of"% targeted" is 1.000 for annual testing and 0.500 for biennial 

testing. Under biennial testing, the estimated PM 10 exhaust emissions reductions decrease as 

well. 

d. Variables in Table 1 have been labeled and defined in the report. 

e. The heavy-duty control factor (HDCF) and the numbers of vehicles tested, initially failed 

and then repaired pertain to HDDVs only. 

f. In order to clarify the computations, DAQ has eliminated references to light-duty diesel 

vehicles and trucks in the appendix pages (9 and 1 0) of our report and in the attached detailed 

computations for Salt Lake and Utah Counties, respectively. The computations have been 

rewritten to make them easier to follow. 

11. EPA needs clarification of the term "weighted average" (see page 9 of report). This 

term appears twice on page 9-in the computations for Salt Lake County and again in the 

computations for Utah County. 

EPA needs clarification of the sentence which reads, "The diesel inventory is both heavyduty diesel and light-duty diesel emissions, so the reduction must be calculated for the 

whole diesel inventory". 

Response: 

a. The term "weighted average" applies to failed HDDVs only. The value of"weighted 

average" is different for each county. 

In addition, the term "weighted average" refers to "weighted average of the value ofHDCF". 

There is a unique value ofHDCF for each model-year group ofHDDVs. Both "weighted 

average" and HDCF are functions of the failed HDDVs. 

b. The inventory includes PMIO emissions from HDDVs only. 

3 
REGULATORYAMENDMENTSTO 

CALIFORNIA'S HEAVY-DUTY VEIDCLE 

INSPECfiON PROGRAM 

AND PERIODIC SMOKE 

INSPECfiON PROGRAM 

TE~CALSUPPORTDOCUMENT 

Prepared by: 

CALIFORNIA AIR RESOURCES BOARD 

and 

ENERGY AND ENVIRONMENTAL ANALYSIS, INC. 

October 1997 

This report has been reviewed by the staff of the California Air Resources and approved for 

publication. Approval does not signify that the contents necessarily reflect the views and 

policies of the Air Resources Board, nor does it mention of trade names or commercial products 

and services constitute endorsement or recommendation for use. 

·1' ' · ·. Attachment 6 
RESULTS OF TRUCKS TIIAT HAVE VISITED REPAIR FACILITIES 

NORTHERN CA.LIFORNJA 

Truck En&ino f.acino Y- FacW Tat Op.city Repair Localioa lllilill 

I 

0 

---r--

l 

3 

6 

14 

IS 

20 

23 

24 28 

37 

.C2 

43 

44 

... 

-

Cummills 

cu.pillar 

Cummiu 

Made 

Cunmias 

lH 

Made 

Cummins 

Caterpillar 

Cummins 

Cummins 

Cummins 

Cummins 

.• ·-:-·. : ... · . • \.,._ ........ "'·-m'·.· • " .-· , . 

... 

NTCJSO 19&0 

19&0 

NTC400 1984 

ETAZB6 

7B. 1971 

NTC-400 1911 

DTo466 1912 

EC63SO 19U 

ISS 1912 

169] 1974 L-10 1919 

NTC400 1984 

L-10 1993 

IS$ 197S 

--- -- -:-_r_--· 

49.6 

<• fihar w .._ 

1/09197 SS.II ]/-4/97 Cummint-SacnmcniO challgod) 

2110191 70.7 l/5197 CaGpillll' • Sui Lc.ndro 70.4 

2125191 52.11 3117197 61.9 

Dind Pcdclnaucc • 

2120191 94.1 4121197 Sacnmcnto 12.6 

3126197 O.S 4122197 Cummins· Su l..andro 40.6 

Riwnicw 1lld3119/97 43.1 4117197 Srocnmcakl Sl.l 

Dow HaaloDd • Modesto (filel pap 

$/1197 iw.naly wodc) 

Diad Pafonunce. 

S/6191 63.1 5116197 SKriiiiCIIto 74.4 

S/19/97 69.1 S/21197 Jticbd1i- Sb:f,:Da 19.7 

T cnt0 T radar • 

4181')7 68.8 S/22197 Sacnmcnto .CI.I 

5127197 46.1 S/21197 I Righetti • Stod;1oa <49.5 

S/24/97 96.9 S/29197 RiKhdli • Slodctoa 96.3 

S/21191 22.2 S/30197 RighcUi • SIOdc1oa 43.4 

SI24."J7 66.7 S/30197 Riellehi • Stodcloll 63.2 

- ------

Rep&in 

Fuel pump calibntod 

,....__. 

l'unlp lllllia& adj 

Ratio fAll*«<l installed. 

Pump recalilnted 

a..-.. puff ... 

llllhllul _.,.oW, IIIII 

IUibo 

Re-calibntod ill_ieclon Repllcod illjocW 

RdJui1t IUcl JIIIIIIP 

Set CMdad. RpiKod 

ilt;tGiar tips, npa-1 

IIRo coolcr,ldjtulcll 

aMrOid 

Adjus1cd fuel ,...., 

Adjultcd CJio'fllleld llld 

fttubed illjedon 

RebuiltAFRC 

Rcp-1 injocton 

Adj AFRC, Oushed 

·uvcc:ton 

Relet Clllioc 0\'abAd 

end rcplt'" I injector 

AdjAFRC 

Relet valves and 

injodon -

Colt 

S495.95 

SI12.J7 

S491.69 S1111.26 

Owllr,.W 

_CMI'I&• 

$741.61 $)69.61 

so.oo 

$1644.31 

Ower to 

S49S.SO 

$396.32 

suo.ss S%6.00 

_!379.46 -

r..a 

-

--

19.0 

67.7 

62.1 

13.11.

19.

2U 

S4.

21.0 

21.

35.9 

13.4 10.4 

23.6 

323 

25.6 

21.2 

11.1 
,J:>. 

I 

• 

-.f· •" •-';,"\> '•''' r\',, ,> ,.,.. ... •or ..... '·"' !>-"·'''" ...... ,..,.,., .. 

RESULTS OF TRUCKS TIIAT IIAVE VISITED REPAIR FACILITIES 

NORTHERN CALIFORNIA 

(Cclalillled) 

TIUCt Eneine Eqille Yw Field Test Oplcity llep!W Locatioa lritial 

- --- ---- ---- - - ----

Flucluatecl 

betweea 

4!i Dcaoit 1\'-71 1973 S/20197 39 and 17 51'1.7197 Dcha Tnd. Ccata- 33.0 

S/29197 

46 Cllllllllins NTC400 1910 5121191 43.1 6fJI91 Rilheni - SIOdcton 46.9 47 CUIIIIIIiu NTClSO 1974 5121191 47.S 6fJI97 Riglletli • Sloclclon S2J 

41 CuaDns NTC350 1914 S/21197 69.3 614191 RichctQ - SIOI:klol 12.4 

6/13197 )2.2 

49 Cummins NTC400 1919 5/28197 45.7 614191 Righetti - Stodcton 40.7 

so Cllmmins NTC3SO 1911 5120/117 4B 6i4197 Ripetti - SD:t1on •u 

5I O.oit 61..-71 1914 6/4197 62.1 6110197 RolL • Stockton 61.6 

52 IH DT466 1976 S/21f<T7 51.4 61llf<T7 lnlcntale - Stodcton .9.6 

53 Dcnit 6-71 1m 41211'17 61.4 611ll'17 R.t:L- Sloclcton 73.7 

S4 Catcrpill., 34068 1917 S/28197 ]9.6 6113197 Holt Bros - Slocktoa 37.1 

ss Catcn!ill., 34068 19&7 S/28197 36.8 6/13197 Holtllrol • Slodctoe 31.9 

56 Catcrptlllt 3176 1993 6113197 21.1 6/13197 Holt Bros - Slockt011 21.2 

S7 Catcrpillu 33068 1984 S/211'17 51.6 6113197 Holt Bros - Sloctton SS.l sa Detroit 6-71 19&S 614197 66.6 61131'17 RieL Diesel- St«k1on 75.7 

59 Catapillar 3176 1990 S/24197 39 6/13197 Hollllrol - St«kt011 37.1 

L__60 BV-92 c__l977 612197 95 6116197 R&.L Diesel - Stoc:ktoa 93.6 

llqllin 

C1eMod air filter 

TIIDHP (let wl-, lmjectan, ... acmnor) 

AdjUSial ftJCI ,_., lutaiW _ .... 

ldwR« 

AdjnodW,_, 

RHCtovabaiad 

frepiiiCOII injedan 

Re-111 ovat.d lid lrepllocd qeclln 

Raot ._.,.delay Repllaci!Vdc• 111111 Rcplleed -*a 

Set dnlde clday, 

,..,._. rock.- 111111, 

RclluiUAFRC 

RebuihAFRC 

Tlllliac IIIII pcnality 

module 

Adjuslod AFRC 1M 

iajoctar IIOIZies 

Set 1hroCtle delay. FOUIId .u-tchod injodon 

and linen 

Sctowdlead 

f<:blngecl_ compuler. 

lnstallocifnUie delay 

Cos

$]4].1

SIIO.O

S922.1

Slllllc

Miw

m6.1

S777.3S777.3

S316.0

1631.6

$541.6

$213.1

S480J

$414.1$706.9

$401.7$984.2

SW.9
r 

I 

I 

-

w 

........... \ ',• ·- ......... ,.. .. -

·1-. ............ -.. 1'""'"'-:··· ··r,...,.--... ... ·-t<· •'.· •·• ...... ,..., .... _ .... .... ..,.. .••• -; .. ·:--r.-"'; .... .... .,., ·T .. ..... .. ......... 

RESULTS OF TRUCKS THAT IIA\'E VISITED REf AIR FACILITIES 

SOUTHERN CALIFORNIA 

TRICk Ena._ £acine Y _. Field Test Opaeily RqiU locati011 lnilial RcpQa Cost 

·-· - - - --- - - - 

I Cuavnills 1'/TC J3S 1971 12119196 62.5 211197 Cummins - R.iallo 9U New IUcl JMIIJI inmlled $100.0

4 CUrnmiDs 1'/TC 365 1990 211&197 72.1 ]IS/97 Cummins- Rialto S7.S Recalibnled lilcl IIURIP $544.

5 Cummins NTC400 1979 216197 63.1 )/6/97 Cummins • Rialto 78.S R-libnted IUcl 5469.99 

Cben&ed ... fdlcr .... 

7 C.llrpiH• 3<106-B 1913 ll&."¥7 62.2 3/l0/97 Calcrpt11ar·Whiaia' su pslcetl S2J9.07 

AFRC reworked $241.15 

Olanced - I CallrpiU.- 3-406-8 1990 214197 19.1 3125/97 Calcrpi!Jar. Whit!Mr 52.9 reWOited AFRC $306.39 

9 Clltnmins NTC400 1986 )/6197 93.2 3126.'97 Cummins - Rialto 95.) 1\acl pump $539.10 

Rcpl--a Injectors Mid 

10 Denil IV-92 1910 3/13197 92.6 l/26/97 Detroit • CiiV of'lnduslry 92.0 holdedclly $944.10 

II CIUIImins NTC400 1911 213/97 75.7 4/J/97 Cummins • Rialto 78.7 Recalibraled lbcl DUIIIP $52.5.15 

RHuilt Stop r-., 

Collftl wM .... oil 

12 Cummins NTC444 1911 3117197 H.S 4/10/97 a-ins- Rialto SI.O lcalc at STC oil rail. 1714.39 

Rcpeir did not bclp 

mudl Sllopl fiWa llat 

6c Wet ... ,. lllw bid 

il;ecton. TNCk wu 

rclcuod bccauiC tuck 

OM* Aid flat ho hid 

to go. 

lJ Calclpillar 3406-.o\ 1911 3117197 96.9 4116197 Caterpillar-Whinier 91.0 Reconditioned AFRC 

Adjusted rail prcSIURI 

16 Cummins NTClSO 198S 419197 -46.9 4123197 Cummins • Riallo 41.0 Uld filellirbec $11.94 

Rec:alilnlod filel pump. 

adjusted 10__. and 

17 CUmmins NTC 350 1914 419197 42.2 4121197 Cummins -Rialto 47.0 AFRC 

Rebuilt Uld adjusted 

IB Cat«pillu 33068 1911 3131197 73.9 .cl30197 Catcrpilw-Whinier 92.-4 file! ratio control 

46.6 

Dift'erencc between field 

and sbop test is t.ec.usc Replaced reversing 

nclc. owner had injec:tors relay valve Uld adjusted 

19 Mack EM6-l00 )983 -4/IS/97 78.7 sn/97 Mack -Anaheim £_leaned and rebuilt. injeclion pu"!!'_ __ $15!.91 
.a:. 

I 

-

.a:. 

-·-··--

ll£SUL TS OF TIUJCICS TIL\ T IIA VE VISITED llUAJR FACILITIES 

SOUTIIEIU'f CALIFOIU'UA 

(Cal!liiM4) 

TIUdt Ea&i- £ape Y _. Field T..a OpKily RopUr Localioa ... 

.. 

_ ... ,_. ...... ....... ... 

21 OamJniu NTC350 1911 :VII/97 61.2 eu-aiu. )doMcWJo 40.9 

ll c-iu L-10 1911 3119197 59.1 S/IS/97 92.9 

lS c--. L-10 11114 S/1919'7 49.7 S/19197 c:-iDa. El Cajaa "''·' 

Po-S)'IMIU • SID 

16 C.tapillv 3-4068 1911 Vl0191 63.7 S/'20197 Dic&o 11.3 

l1 CununiN L-10 '"' S/1197 66 ... Culnnaina - El CajGII 12.0 l9 CUmmins NTClSO 1917 3/11197 61 5122197 Cuaniu. Riallo 0.1 

lO Ollllmiaa NTC 1919 ll5l'n 10.1 Slll/97 o-M. .Jtiallo 9ll 

611919'7 c-.ina- Maalcldlo 71.1 

Powers,...... Sea 

ll C..tapillv 3306 B 1975 S/1197 5122197 IDieao 11.0 

12 Cummins NYC .COO 1979 S/1191 72.6 CUmmins- El C.joa 10.6 

33 CumnUna L-10 1917 S/1197 63.9 SI2'JN1 !Cummins- El Cejoa 76.0 

l-' Mack EC0-350 1911 S/1197 61.2 5f2fJI97 ElcW f.qllipaacal )1.4 

Powar SY5\CIII1 • SID 

C.tcrpilllr )3068 1916 S/1197 .QicacL_ 9S.O 

.... eo. F"..& 

--= 

1472.13 21.1 I 

0...10 I 

a.,... IMcelilmM ,.y-.. I 

........ «MrSJ.'* 59.0 

.............. I 

........ SI9SU6 13.1 

o..r• 

........ ....... 4U 

.......... 

...... $1,.232.11 2U 

.................. 

..... -....< 

_..., 

.......... 

$175.15 11.1 

F.! ... $)91.91 34.1 

I AdjuiiM AfRC $247.71 11.1 

......... 

....... SMI.71 61.3 

Miu ........... ll se.uo 35.6 

................. 

--. ...... _.. Sl 039.20 lU 

A4u*IW..-.. 

TNCklloall&waW 

_ .. '-"42.Z7 31.7 

Fuel Plap c.&lntiaa J6.1 

................. 

air oooa., IIIII GiiGI S14t.S6 S6.7 

S63US 

RMiltW.-pllllt O.W.IO 

PI}'_ 29.1 

lilaia&.fild..uillp 

:valva. air ruecr S696.l9 19.4 
Tmk Encinc Encine 

··- - ... 

-

... 

-

36 DOC Series60 

ll Cwrunins NTCJSO 

39 Cummins NTCJSO 

.co Cummins L-10 

I 

Vl 

41 Cummills 

61 Detroit 6V-92 

62 Caterpillar )4068 

66 Made. EC6 

68 Caterpillar 3406-B 69 3406-B 

RESULTS OF TRUCKS TIIAT IIAVE VISITED REPAI'R FACILITlES 

SOUTIIERN CALIFORNIA 

(Continued) 

Year f'ICid Teat OpKity Locali011 lnilid 

--·- ---

1919 58.3 S/21191 \'aiJc::yDOC FOI.&.ot 1o talce initial rest 

1984 411197 17 S/27/97 Cummins - Montebello 96.0 

1979 4flfC17 11.6 S/21/97 Cummiru • 1\fontebeRo 19.0 

Did nolllavc IIICtcr lo 

1987 S/23197 72.6 S/29197 Cummins- El Cajon talce test 

6113197 ., 

Did aot have • 

1985 18.2 5127197 Cummins • El Caj011 talce test 

Valley DOC ·City of 

1979 S/27197 69.1 6/10.197 Industry 71.9 

Harbor Diesel • Long 

6119197 Beach 67 

1988 5/21/97 13.6 6116/97 Power Systems • Whillier 81.3 

1988 72.5 6/12197 ·Anahiem 93.5 

1990 1125197 12.1 2121/97 Caterpillar-Whinier 1986 SI2JI97 49.2 6/20197 San '--· 7 

Jlepein 

Repl&oed 2 injoclon lind 

exhaaut llllllifokl 

Repded lilcl pump lind 

installed miuinc AFRC 

I puts 

Jlepairod fUel pump IIIII 

ini1Uicd missinl AFRC 

I puts 

Repeirecl ilol pump 

Flush lind tune. replacod 

lilljocton 

rocker ums 

NICII injec10r 

Reset lhroltlo delay 

Llnflluued lbroetlc 

delay orifa 

RcbuiltAFRC Repaired fuel pump Reassembled AFRC 

valve lhal \VIS sticking 

Replaoed nozzles 

Cost 

SI2Ss.&l 

Own« to 

pay$200 

$793.19 

s<J06.73 

S54U4 

$959.91 

S1S9.94 

roundodlo 

mo 11y 

Cummins 

S7S5.6S 

S710.60 

$176.26 

$1,962.38 

S2.C7.00 

$805.93 1 
. . .. 

CHAPTER 7 

BENEFITS OF THE HDVIP AND PSIP 

OVERYJEW 

As with the cost analysis, the emissions impact analysis in this report evaluates the impact of 

· the overall inspection programs compared to having no such programs. The StaffReport also 

. includes an incremental analysis showing the impact of the programs with the proposed 

amendments incorporated, compared to the originally-adopted programs. 

Implementation of the HDVIP and PSIP will produce a series ofbenefits that can be 

generally classified as follows: 

• A reduction in the number of heavy-duty diesel vehicles emitting excessive smoke; 

• A reduction in criteria and toxic air pollutant emissions from heavy-duty diesel vehicles; 

• A reduction in heavy-duty diesel vehicle fuel consumption; 

• A potential improvement in heavy-duty diesel vehicle reliability and performance. 

Reducing the number of excessively-smoking heavy-duty diesel vehicles is the primary goal 

of the HDVIP and PSIP. Reductions in criteria and toxic air pollutants, reductions in fuel 

consumption, and any improvements in vehicle reliability and performance accrue as direct, but 

secondary, benefits of the smoke reduction repairs. 

This chapter presents estimates of the magnitude of reductions of excessive smoke, criteria 

pollutants (i.e., hydrocarbons or ROG, NOx and PM), and fuel consumption that will accrue due 

to HDVIP and PSIP implementation. Estimates have not been developed for toxic air pollutant 

reductions or any heavy-duty diesel vehicle reliability and performance improvements arising out 

of program implementation, primarily due to a lack of definitive data on which to quantify the 

magnitude of such benefits. Studies necessary to determine the magnitude of toxic air pollutant 

reduction and vehicle performance benefits could be conducted as an integral component of the 

HDVIP and PSIP programs simultaneously with active program enforcement. As demonstrated 

below, the HDVIP and PSIP are very cost-effective programs, even in the absence of explicit 

estimates for these secondary program benefits. 

Section 7.2 presents estimates for the HDVIP- and PSIP-driven reduction in the number of 

excessively-smoking heavy-duty diesel vehicles operating in California. Section 7.3 presents 

estimates of program-driven reductions in criteria pollutant emissions. Finally, Section 7.3 

presents estimates for the quantity of diesel fuel saved due to HDVIP and PSIP implementation. 

7-l 
7.2 REDVCIION IN mt NVMBEB Qf YEBICLES IM1TIING Ex:CESSIYE 

SMOKE 

Generally. the effectiveness of an emissions control program is measured in terms of dollar 

cost per mass. of pollutant redU<:ed. However. since the primary goal of the HDVIP and PSIP is 

to reduce the level of smoke emissions from bea.v.y-duty diesel veh;i(;les.. such a metric is of no 

utility in quantifying primary prog,ram benefits. Smoke emi!.W>Ds are not measured on a mass 

basis and cannot be added &a"OS$ aD operating heavy-duty diesel vehicles to provide a useful 

measure of the total quantity of smoke reduced thtoug.h the HDVIP and PSIP. The most 

reasonable measure for evaluating HDVIP and PSIP sue~ ia reducing SlOOke emissions is 

through aa estimate of the program-induced decrease in she number of heavy-duty diesel vehicles 

with excessive smoke emissions operatin& in California. 

Tbe 1990 'TSD presented a detailed theoretical analysis of the expected redu~ion in the 

number ofheavy-duty diesel vebicles with excessive smoke emissions operating in California 

between 1990 and 199S due to the- implementation of the original HDVIP. While the details of 

that analy~ are not reproduced here. a decline in the fi:actioa ofexcessivety-smoking vehicles 

from 44 pereent of the hea'V)"-dut)r diesel fleet in 1990 to 21 pen:ent of the fleet in 1995 was 

predicted. Section 6.5.2 ofthis TSD discusses data collected under the original HDVIP that 

provides a compelling vatidaboa of tile 1990 Tsn·s analysis. Mcrreover~ this observational data 

provides a firm foundatioft on which to base the expected decline in excessive smoke emissions 

due to implementation of the proposed HDVIP and PSlP. 

Data from the original HDVIP indicates that approximately 4S percent of heavy-duty diesel 

vehicles were emitting excessive smoke during the first few months ofthe program in I991. By 

the end of t993 ~ this ftaction had declined to lll.S: percent.. readily illwstrating the effectiveness of 

that program m reducing die number ofvehides with excessive smoke emissions~ The recent 

Random Tru<:k Opacity Survey, conducted in support ofthc: proposed HDVIP and PSIP, 

indicates that the current failure rate for the same subset of vehicles subject to· the original HDVIP 

(i.e., pre-1993 model year heavy-duty diese~ vehicles) is approximately 20 percent (for an 

equivalent-stringeMy opaeity standard and adjusting for freet aging). Therefore, while there 

apparently has been some backsliding of maintenance pramces since the suspension of the original 

HDVIP, the- effects. of that program remain strong and the number of heavy-duty diesel vehiclesemitting excessive smoke continues to be well' below that whicft would be observed if the program 

were never implemented. It seems. reaso.nabte. however. to expect that over time, the percentage 

of !:tea-vy-du:ty dieset vehides with oeessiv.e smoke emissiQn,s, wilt continue tel)- increase if the 

proposed: HOVIP' and PSIP are- not implemented. eventually stabiTtzing at a.leve~ near that 

observed at the- beginning of the original! HDvtP. 

In addition ro preserving the current gains made through: the implementation of the original 

HDVIP. implementation of the proposed HD·VIP and PSIP will promote a renew~td emphasis on 

vehicle maintenance and a corresponding furtheli reduction. in the number of excessively-smoking 

vehicles in California. It is estimated that after the first full year of implementation ofthe 

proposed HDVIP and PSIP (i.e., 1999), an additional 7 percent decline in the number of 

7-2 

' ·- .. 
excessively-smoking heavy-duty diesel vehicles will be observed through the renewed promotion 

of deterrence-based vehicle maintenance (returning such maintenance practice to the same rate of 

occurrence as obseiVed at the time of suspension of the original HDVJP and avoiding further 

erosion of the gains of that program). This translates into a estimated 70,472 excessivelysmoking heavy-duty diesel vehicles in California in 1999 as opposed to 74,503 in the State 

without the proposed HDVIP and PSIP. Similarly, the number of excessively-smoking heavyduty diesel vehicles in California in 2010 is estimated to be 67,657 with the proposed HDVIP and 

PSIP and 71,526 without the programs. 

These reductions should be viewed in a larger perspective in that the indicated decline in 

excessively-smoking heavy-duty diesel vehicles (4,030 vehicles in 1999 and 3,869 vehicles in 

2010) is but a fraction of the total decline due to HDVIP and PSIP implementation. In the 

absence of the lingering deterrence effects of the original HDVIP an additional24,747 

excessively-smoking heavy-duty diesel vehicles would be in operation in 1999 and an additional 

33,710 excessively-smoking heavy-duty diesel vehh,; .. .; would be in operation in 2010. Therefore, 

the overall reduction in excessively-smoking heavy-duty diesel vehicles is 28,778 in 1999 and 

37,580 in 2010. These reductions equate to a 29 percent reduction in excessively-smoking trucks 

in 1999 and a corresponding 36 percent reduction in 2010. While the bulk of the original 

HD'VIP-driven share of the reduction for 1999 can be presumed to occur regardless of 

implementation ofthe proposed HDVIP and PSIP (given the fact that most of the 

deterrence-driven reduction is currently in place), there is no assurance that the estimated 

reduction for 2010 would not erode substantially if enforcement of smoke standards is not 

resumed. Between 1999 and 2010, much, ifnot all ofthe lingering deterrence effect ofthe 

original HDVIP could be lost without implementation of the proposed HDVIP and PSIP. 

7.3 REDUCTION IN CRITERIA POLLUTANT EMISSIONS 

Repairs and deterrence effects of the HDVIP and PSIP will not only reduce the number of 

vehicles with excessive smoke emissions, but will also reduce mass emissions of criteria 

pollutants. However, the determination ofHDVIP and PSIP impacts on criteria pollutant 

emissions is complex, involving such factors as detailed data on emission control system 

mal performance, the effect of individual malperformances on criteria pollutant emissions, the 

ability of the HDVIP and PSIP to identify individual malperformances, and the success of vehicle 

repairs in correcting identified mal performances. This subsection presents an estimate of these 

factors and the resulting magnitude of the criteria pollutant impact for ROG, NO", and PM. CO 

emissions from diesel vehicles are low relative to their gasoline counterparts (due to excess air 

combustion conditions) and therefore are not addressed in this analysis. The ARB MVEI7G 

emissions inventory model indicates that diesels in total are responsible for only about 3. 5 percent 

of vehicular CO emissions in 1999 and about 7.5 percent of vehicular CO emissions in 2010. 

Subsequent to the preparation of the 1990 TSD, the ARB updated their MVEI7G emissions 

inventory model to estimate the criteria pollutant impacts of a heavy-duty diesel vehicle smoke 

inspection program such as that proposed. Using the MVEI7G model would greatly simplify the 

7-3 
detennination of criteria pollutant emission impacts since the model represents the State's official 

emissions inventory estimation tool and would provide a direct link between the analysis of 

HDVIP and PSW emission reductions and the overall State emissions inventory. Moreover, since 

ARB modeling staff indicates that the encoded MVEI7G algorithm to estimate emission reduction 

impacts was based on the methodology outlined in the 1990 TSD, the theoretical foundation for 

the algorithm is both documented and well understood. 

Unfortunately, preliminary emissions analyses using MVEI7G indicated problems with 

practical application of the model algorithm. First, the model did not account for the deterrence 

effects of the smoke inspection program, instead assuming that only those vehicles that are 

actually inspected and issued citation make any repairs. As experience with both light duty 

vehicle inspection programs and the original HDVIP indicate, there is a sizeable deterrence effect 

due to program implementation that must be accounted for in quantifying program benefits. 

Second, the MVEI7G model-assumed failure rate for individual model year vehicles is invariant 

over time. For example, a 1990 model year vehicle fails at the same rate in 2010 (when it is 20 

years old) as it did in 1995 (when it was S years old). Such an assumption is not consistent with 

test program data such as that discussed in Section 6.4. Finally, the pollutant-specific impact 

coefficients encoded in MVEI7G are not consistent with the 1990 TSD modeling upon which the 

MVEI7G algorithm was based. In fact, individual repairs would have to reduce emissions by 

more than 100 percent in some cases for the coefficients encoded in MVEI7G to be accurate. 

To sunnount these issues while at the same time retaining the advantages ofMVEI7G in 

terms of overall consistency with the State inventory (including consistency of overall vehicle 

counts, model year distributions, and vehicle class distributions), alternative sets of input 

parameters for use in the MVEI7G emissions impact algorithm were developed to properly 

consider all HDVIP and PSIP impacts. The MVEI7G algorithm can effectively recognize five 

distinct HDVIP- and PSIP-related parameters as follows: 

• The calendar year-specific heavy-duty diesel vehicle inspection rate; 

• The model year-specific failure rate within each class of heavy-duty diesel vehicles; 

• The calendar year-specific failed vehicle repair rate; 

• Model year- and pollutant-specific (ROG, NOx, and PM) emissions impact factors; 

• A calendar year-specific "discount" factor to correct for the phase-in of program 

benefits during initial inspection years. 

Revised data was developed for each of these five parameters for both 1999 and 2010 to 

analyze HDVIP and PSIP benefits. 

7.3.1 Pollutant-Specific: Emissions lmpac:t Fac:toa 

As indicated above, the pollutant-specific emissions impact factors encoded in the MVEI7G 

model imply a greater than 100 percent emission reduction effectiveness of repair in some cases. 

Therefore, these factors were revised for this analysis to better reflect the actual emission 

7-4 

. . 
reduction benefits of vehicle repair. The basic smoke program-induced correction algorithm 

encoded in MVEI7G is: 

where: BER CF is the basic emission rate correction factor for vehicle class "i", 

model year "j", and pollutant "k" due to smoke program implementation, 

IR is the smoke program inspection rate for vehicles in class ''r' in the calendar 

year being modeled (in percent), 

RR is the fraction of failed vehicles in class "f' repaired in the 

calendar year being modeled (in percent), 

FR is the smoke program failure rate for vehicle class "f' and 

model year "j" (in percent), and 

PSIF is the emissions impact of repairs for vehicle class "f' 

and model year "j" on pollutant "k" (in percent). 

The structure of this algorithm is quite complex, especially the term involving the inverse of 

the failure rate (FR) and pollutant-specific impact factor (PSIF). Nevertheless, the basic emission 

rate correction factor (BER CF) should be equivalent to a calculation based on a simple pollutant 

mass balance as follows: 

BER CF = (Fraction Not Repaired) (1) + (Fraction Repaired) (ERCF) 

= (1 -Fraction Repaired) + (FractionRepaired)(ERCF) 

= 1 - ( !o) ( ~:0) ( :) + ( ~~) ( :) ( ~) (ERCF) 

where: ERCF is the fraction of pre-repair emissions left after a smoke 

program-induced vehicle repair. 

7-5 

==~----------------.. ·~ 
• • .... 

TABLE 7-1 

CATALYST AND PARTICULATE TRAP DEFECT FREQUENCIES 

· .. ·. ·.•. ....... ·.· . . ·. < 

. Defect · 

HHDDV 0.00 0.00 

MHDDV 0.00 0.01 

Catalyst Removed 

LHDDV 0.00 0.03 

Urban Bus 0.00 0.00 

HHDDV 0.40 I 0.501 0.00 

MHDDV 0.30 0.00 

Trap Removed 

LHDDV 0.30 0.00 

Urban Bus 0.05 0.00 1 California-certified engines I Federally-certified engines. 

7-7 
.. 

( 

TABLE 7-l 

EMISSION REDUCTION CORRECfiONS FOR AVERAGE REPAIRS 

.. :.-. 

Vehicle Oasi . Model Y earl . ROG NO* PM 

Pre-1987 0.8211 0.9817 0.6411 

1988-1990 0.8349 0.9869 0.6798 

HHDDV 

1991-1993 0.7952 1.0008 0.7123 

1994 and Later 0.8046 1.0008 0.6755 

Pre-1987 0.8171 0.9934 0.6650 

1988-1990 0.8258 0.9967 0.6990 

MHDDV 

1991-1993 0.7464 1.0037 0.6693 

1994 and Later 0.7549 1.0037 0.6243 

Pre-1987 0.8432 0.9926 0.7492 

1988-1990 0.8442 0.9939 0.7514 

LIIDDV 

1991-1993 0.7542 1.0007 0.6772 

1994 and Later 0.7627 1.0007 0.6388 

Pre-1987 0.8914 1.0021 0.8063 

1988-1990 0.9254 1.0041 0.8716 

Urban Bus 

1991-1993 0.8768 1.0024 0.7887 

1994 and Later 0.8784 1.0024 0.7906 

7-8 

; 

.. ' 
.. 

TABLE 7-3 

EMISSION REDUCTION CORRECTIONS FOR FULL REPAIRS 

.. Vehic1~·a~ss .· ModeLYears ROG·. ·NO,. PM 

Pre-1987 0.5879 0.9450 0.4257 

1988-1990 0.6201 0.9086 0.4625 

HHDDV 

1991-1993 0.5518 0.8488 0.3923 

1994 and Later 0.5482 0.8488 0.2965 

Pre-1987 0.5407 0.9309 0.4268 

1988-1990 ,... 5562 0.9280 0.4552 

MHDDV 

1991-1993 0.4376 0.9004 0.3249 

1994 and Later 0.4324 0.8919 0.2173 

Pre-1987 0.5474 0.9996 0.5116 

1988-1990 0.5477 0.9908 0.5117 

LHDDV 

1991-1993 0.4221 0.9083 0.3278 

1994 and Later 0.4163 0.8961 0.2154 

Pre-1987 0.6761 0.9545 0.5882 

1988-1990 0.7457 0.9885 0.6886 

Urban Bus 

1991-1993 0.6606 0.9741 0.4514 

1994 and Later 0.6520 0.9741 0.4474 

., 7-9 
,. 

,. 

( 

, -

.. 

.. 

7 .l.l Ych jclc ln.spcc:tion Bate 

Conceptually, quantifying the inspection rate for the HDVIP and PSIP is a straightforward 

calculation of the ratio of the number of vehicles inspected to the number of vehicles in use. 

However, because the smoke inspection program correction factor algorithm encoded in the ARB 

MVEI7G emissions inventory model is fairly simplistic and does not incorporate any explicit 

mechanism for considering the deterrence-driven maintenance impacts of the HDVIP and PSIP, 

these impacts must be modeled using the standard "inspection-failure-repair" algorithm presented 

above. Effectively. the impacts of any smoke inspection program can be broken down into two 

basic components: (1) the impacts of repairs resulting from actual inspection failure and (2) the 

impacts of deterred tampering and preventive maintenance undertaken to minimize failure risk. 

The former impacts are limited by the actual number of vehicles inspected while the latter impacts 

affect a far greater vehicle population. Therefore, a simple encoding of the fundamental HDVIP 

and PSIP inspection rate into the MVEI7G model will significantly underestimate overall program 

impacts. 

As discussed in Section 6.5.2, approximately 26 percent ofheavy-duty diesel vehicles are 

expected to exhibit reduced emissions due to either deterred tampering or increased maintenance. 

This estimate is based on actual smoke inspection program experience in California, gleaned from 

original HDVIP data collected between 1991 and 1993. As stated in Section 6.5.2, this 

deterrence effect was originally hypothesized in the 1990 TSD and has subsequently been 

effectively confirmed in actual practice through the original HDVIP. 

Since the MVEI7G smoke inspection correction factor algorithm does not include an 

explicit mechanism to address this deterrence fraction, it must be modeled through its equivalent 

impact on the effective vehicle inspection rate. This rate significantly exceeds the actual 

inspection rate calculated strictly on the basis of physical inspections performed. The effective 

inspection rate can be alternatively viewed as that rate ofinspection that would bring about the 

same improved maintenance behavior in a fleet of vehicles that undertook no improved 

maintenance except in instances of smoke inspection failure. 

7.3.3 Yebjde Failure Rate 

As was the case with the vehicle inspection rate, quantifying the basic vehicle failure rate for 

the HDVIP and PSIP is a conceptually straightforward calculation ofthe ratio of the number of 

vehicles failed to the number ofvehicles inspected. However, the deterrence effect that affects 

the vehicle inspection rate, as described in Section 7.3.2, carries over to affect the failure rate 

calculation as well. In effect, 100 percent ofvehicles undertaking deterrence-based maintenance 

are assumed equivalent to inspection "failures". Therefore, the effective HDVIP and PSIP failure 

rate is the effective inspection population-weighted average ofthe 1999 and 2010 model year and 

class-specific failure rates presented in Table 6-6, and an effective failure rate of 100 percent for 

deterrence-driven repairs. Light-heavy-duty diesel vehicle failure rates have been estimated by 

adjusting the medium-heavy-duty failure rates presented in Table 6-6 by a factor of one-third. 

7-10 
This correction factor for light-heavy-duty diesel vehicles is derived from the default class-specific 

smoke program failure rates encoded in the MVEI7G model. 

7 .3.4 Failed Vebjclc Repair Rate 

Quantifying the basic vehicle repair rate for the HDVIP and PSIP is a conceptually 

straightforward calculation ofthe ratio of the number ofvehicles repaired to the number of 

vehicles failed. But once again, the deterrence effect described in the Sections 7.3.2 and 7.3.3 

carries over to affect the vehicle repair rate calculation. Since 100 percent of the malfunctions 

undertaken through deterrence-based maintenance are corrected, these vehicles exhibit both a 100 

percent repair rate and an individual pollutant-specific repair impact that is greater than the 

aggregate impacts of average defect identification rates and average defect correction rates. The 

effective HDVIP and PSIP repair rate is the failed vehicle population-weighted average of the 

78.5 percent repair rate for vehicles that were physically inspected and failed, as observed in the 

original HDVIP (and assumed for the proposed m::·.""!P and PSIP, see Section 6.5.1) and an 

effective repair rate of 100 percent for deterrence-driven maintenance. Moreover, the average 

and fully-successful pollutant-specific impact factors (PSIF) presented in Tables 7-2 and 7-3 must 

be aggregated by this same weighting factor to derive appropriate calendar year-specific PSIF 

values for input into MVEI7G. 

7 .3.5 First Year Pro2ram Benefit Discount 

The MVEI7G smoke inspection program correction factor algorithm discounts first year 

emission reduction benefits by 50 percent and assumes zero benefit for calendar years in which no 

smoke inspection program is in place. While this makes intuitive sense, it is not explicitly correct 

for calendar years, such as 1994 through 1998, where there are residual carryover maintenance 

impacts associated with a previously-operating smoke program (in this case the original HDVIP). 

However, this is not a concern for the 1999 and 2010 emissions modeling performed in this 

analysis and has, therefore, not been altered. Full HDVIP and PSIP emission reduction benefits 

are assumed in both emissions analysis years. 

7.3.6 The No HDVIP and PSIP Baseline 

In the standard MVEI7G emissions inventory model, emission loads without a smoke 

program in place cannot be estimated in a calendar year during which a smoke program is in 

effect. The MVEI7G model assumes that a smoke program either is or is not in place in any 

given calendar year and cannot be instructed to model the same year both with and without a 

smoke program. To surmount this problem and derive both "with HDVIP and PSIP" and 

"without HDVIP and PSIP" emission estimates, a modified version of the MVE17G smoke 

program parameter input table was developed that included a vehicle failure rate of zero for all 

vehicle classes and model years. This input table forces the basic emission rate correction factor 

to unity, thereby providing an estimate of uncorrected heavy-duty diesel vehicle emission rates. 

7-1 l 

r 

t 

! 
• • 

MD' -----------------------------------

7.3.7 MVEI7G-Estjmated HDVIP and PSIP Emission Reductions 

Appendix C presents the MVEI7G input parameter files used to model the impacts of the 

HDVlP and PSIP in 1999 and 2010, respectively. These input files are designed to incorporate 

both direct failure-driven repair impacts and impacts accruing as a result of deterrence-driven 

vehicle repair. The Statewide criteria pollutant emission reductions estimated by MVEI7G are 

presented in Table 7-4. As indicated, the HDVlP and PSIP are expected to reduce 1999-ROG 

emissions by 6.37 tons per average day, 1999-NO" emissions by 12.24 tons per average day, and 

1999-PM emissions by 5.23 tons per average day respectively. Similar reductions in 2010 of 5.30 

tons ofROG per average day, 14.04 tons ofNO" per average day, and 3.20 tons ofPM per 

average day are predicted. (MVEI7G predictions of tons per summer day and tons per winter day 

were converted to tons per average day by assuming summer emissions are applicable eight 

months of the year and winter emissions are applicable four months of the year. The net effect of 

this weighting scheme is negligible since there are no significant differences in estimated summer 

and winter impacts.) 

The considerable difference between the MVEI7G-estimated baseline emission estimates for 

ROG, NO~, and PM relative to corresponding estimates derived under the alternative 

methodology documented in the 1990 TSD (even after considering the impacts of fleet turnover) 

raises some concern that MVEI7G may not account for the full level of vehicle malperformance in 

determining baseline heavy-duty diesel vehicle emission rates. Nevertheless, given the standing of 

the MVEI7G model, the estimates presented in Table 7-4 were used without alteration to estimate 

HDVlP and PSIP cost effectiveness in the "dollars per pound" format commonly used to evaluate 

other emission control programs. Given the observed differentials between MVEI7G baseline 

emission estimates and corresponding estimates developed in the 1990 TSD, the derived cost 

effectiveness estimates should be viewed as a conservative indicator of program value. 

7.4 FUEL CONSUMPTION IMPACTS 

The same basic malperformance model used to estimate the impacts of smoke repairs on 

criteria pollutant emissions (as described in detail in Section 7.4 of the 1990 TSD) also generates 

a corresponding estimate of the effect of smoke repairs on diesel fuel consumption. While this 

impact is modest, it is nevertheless positive and does accrue as a direct result ofHDVIP and PSIP 

implementation. Based on the population-weighted repair impacts predicted by the emissions 

malperformance model, a net decrease in diesel fuel consumption of0.69 percent in 1999 and 

0.66 percent in 2010 is estimated in response to HDVIP and PSIP implementation. Using the fuel 

consumption estimates forecast by the MVEI7G model for those years, the net diesel fuel savings 

expected as a result ofHDVIP and PSIP implementation is 16.74 million gallons in 1999 and 

19.22 million gallons in 2010. 

7-12 
" ( 

TABLE 7-4. 

HDVIP AND PSIP CRITERIA POLLUTANT REDUCfiONS 

Total Total HDVIPand 

On-Road PSIP Calendar Pollutant · .. Vehicle BDDV Emission Yea.-· . .. .. . Emissions Emissions Reductions . . (tpd) . (tpd) (tpd) 

ROG 1063.97 48.66 6.37 

NO. 1597.68 443.16 12.24 

1999 

PM 52.61 28.96 5.24 

Total 2,714.26 520.78 23.84 

ROG 441.09 40.33 5.30 

NOX 1100.15 404.42 14.03 

2010 

PM 45.19 17.74 3.19 

Total 1,586.43 462.49 22.53 

7-13 
Attachment 7 

Multiple Smoke Opacity Measurements as Indicators of 

Particulate Emissions for Heavy-Duty Diesel Vehicle 

Inspection and Maintenance Programs 

Christie-Joy Brodrick, graduate student 

Institute of Transportation Studies 

University of California, Davis 

Davis, CA 95616 

phone: (916) 752-1934 

fax: (916) 752-6572 

cjbrodrick@ucdavis.edu 

Daniel Sperling, Ph.D. 

Director, Institute of Transportation Studies 

University of California, Davis 

Davis, CA 95616 

phone: (916) 752-7434 

fax: (916) 752-6572 

dsperling@ucdavis.edu 

Christopher S. Weaver, P.E. 

Engine, Fuel, and Emissions Engineering 

9812 Old Winery Place, Suite 22 

Sacramento, CA 95827 

phone: (916) 368-4770 

fax: (916) 362-2579 

csw-efee@holonet.net 
Acknowledgement 

The authors would like to thank Professor Dan Chang, University of California, Davis, for his 

oversight of this work. We would also like to thank the University of California Transportation 

Center for funding this research. 
1.0 Introduction 

Heavy-duty diesel vehicle use is expanding everywhere. In the U.S., California Air 

Resources Board (CARB) estimates that between 1990 and 2010, the number of trucks will 

increase by 70% and vehicle miles traveled will increase by 60% (CARB, 1998). In developing 

countries, the demand for freight movement and hence trucks will grow faster than gross 

domestic product and population (World Bank, 1996). The highest growth rates are predicted for 

Central and Eastern Europe, where trucking activity is expected to triple by 2015 (World Bank, 

1996). 

Heavy-duty diesel vehicles are a significant source of particulate (PM) and nitrogen oxide 

(NOx) emissions in the U.S. On-road heavy-duty diesel vehicles contribute 30% of PM and 65% 

of NOx created by on-road vehicles (CARB, 1997). Furthermore, diesel exhaust releases 

particles at a rate of about 20 times greater than gasoline-fueled vehicles. 

In developing countries, it is estimated that motor vehicles contribute 60% to 90% of all 

urban air pollutants (WHO, 1996). A large obstacle to quantifying the contribution of heavy-duty 

diesel vehicles is the poor data quality and general lack of data on emissions in developing 

countries. However, it is well known that heavy-duty vehicles in developing countries, many of 

which are poorly maintained and over twenty years old, are major sources of urban pollution. 

The heavy-duty vehicle portion of emission in developing countries may not be as great as that in 

the U.S. due to the other significant sources of pollution in the developing world, such as twostroke motorcycles and stationary industrial sources. 

In both the U.S. and developing countries, interest in controlling diesel em1sswns has 

increased in response to mounting evidence that diesel exhaust has a highly adverse impact on 

health. Diesel exhaust includes over 40 substances that are listed by the U.S. Environmental 

Protection Agency as hazardous air pollutants and by the Air Resources Board as toxic air 

contaminants (CARB, 1998). Diesel particulate emissions specifically are under scrutiny due to 

the large quantity produced and their association with human respiratory problems. Exact 

biological mechanisms are not completely understood, but small particles (less that 2.5 microns in 

diameter) are believed to be pose the most severe health risks (Vedal, 1997). 92 percent of diesel 

particulates are less than 1 micron in diameter (CARB, 1998). These particles are in the size 

range that can be inhaled and eventually trapped into the bronchial and alveolar regions of the 

lung. 

In the U.S., advances in engine design, fuel quality, and emissions controls, have led to a 

decrease in certified emissions level. Despite this, in-use PM emissions are estimated to be much 

greater than emission standards due to poor maintenance, general systems failures, and 

tampering. For the 1995 heavy-duty vehicle fleet, the average emissions increases over the useful 

life of a vehicle are estimated at 34% for VOC, 6.6% for NOx, and 43.7% for particulate (NRC, 

1995). Because of the complexity and cost of emissions testing very few in-use emissions 

measurements have been made in developing countries. A rare World Bank study of bus engine 

emissions in Chile found that the in-use bus NOx and PM emissions increased by a factor of four 

due to poor maintenance and system failure (Escudero-Ortuzar, 1991 ). The large amounts of 

black smoke, which is an indicator of high emissions and vehicle malfunction, visible from 

vehicles in cities such as Jakarta, Bangkok, and Tehran, indicate that the trend is likely 

generalizable to many developing countries. 

The most common approaches for reducing in-use vehicle emissions is conduct routine 

inspection programs, and require that improperly functioning vehicle be repaired. Heavy-duty 
vehicle inspection and maintenance programs are prevalent in the U.S. and gaining favor in 

developing countries. The potential impact of proper heavy-duty vehicle maintenance is 

illustrated by the Chile study where overhauls of buses resulted in a 75% reduction in particulate 

emissions (Weaver, 1996). 

Options for inspection and maintenance programs include visual inspection, 

dynamometer testing, remote sensing, and smoke opacity testing. The criteria for selecting 

effective liM programs includes cost, ease, safety, accuracy, and enforceability. The most 

accurate liM procedure would be to measure emissions by running the vehicles on a 

dynamometer and analyzing the concentration of the specific pollutants, similar to what is done 

for light-duty vehicles in the California Smog Check II Program. However, even in developed 

countries, this is usually excluded as an option for heavy-duty vehicles due to the high costs of 

heavy-duty dynamometer testing and safety risks involved in testing poorly maintained heavyduty vehicles. Recently remote sensing has been applied to heavy-duty vehicles, but it lacks the 

sensitivity to be used in enforcement programs. In the U.S., smoke opacity tests are most often 

employed as indicators of malfunctioning and hence high emitting vehicles because of the lowcost, ease, and safety. 

There are five smoke opacity procedures, the snap-idle, idle, cruise, acceleration and lugdown, that are established tests for identifying malfunctioning engines in heavy-duty liM 

programs. The most frequently used technique is the "snap-idle" (or "snap-acceleration"), that 

loads the engine using its own inertia, as the engine is rapidly accelerated from idle to full 

(governor-limited) speed. This technique and the smoke measuring equipment have been 

extensively defined in the Society of Automotive Engineers procedure SAE J1667 (SAE, 1994). 

This is the procedure used in California's heavy-duty on-road liM program. 

Unfortunately, the relationship between snap-idle smoke opacity tests and PM emissions 

are only fair-to-poor (Duleep, 1997). This is not surprising since PM emissions differ 

considerably depending on engine operation. The snap-idle or any of the other smoke tests alone 

are not representative of the myriad driving conditions where PM emissions vary. For example, a 

malfunctioning smoke puff limiter results in a thick black "puff' of smoke when a truck 

accelerates, but does not affect emissions under other conditions. This would produce very high 

smoke opacity measurements in the snap-idle test, but would have only a modest impact on PM 

emissions over the entire driving cycle. Conversely, a dirty air filter or worn fuel injector could 

double PM emissions over the entire driving cycle, but would have only a modest effect on smoke 

during acceleration. Thus, the snap-idle test could identify high emitters with malfunctioning 

smoke puff limiters, even if they were not especially high emitters of PM, but might not identify 

high PM emitters with dirty filters or poor injectors. 

Since reduction of in-use PM is an increasingly high priority, it is desirable to develop a 

procedure that better identifies high PM emitters. The purpose of this research is to investigate 

alternatives to associating smoke to PM indirectly through vehicle malfunctions and to running 

expensive dynamometer tests. A desirable approach would be to run several smoke tests, which 

together were indicative of the PM emissions over a driving cycle. To date there has been no 

published effort to specify the relationship between PM emissions measured over a driving cycle 

and smoke from a combination of smoke tests. Since smoke opacity is directly related to PM (the 

Lambert-Beer Law) when both are measured simultaneously, it is hypothesized that 

measurements of smoke under a variety of driving conditions could be used to predict PM 

produced during a driving cycle by weighting several smoke test results by the portion of the 

driving that the smoke test condition represents. 
.. 

To do this, smoke and PM levels in different modal operations (acceleration, 

deceleration, cruise, and idle) in the driving cycle would need to be characterized. Since current 

on-road smoke opacity tests are not necessarily indicative of driving cycle conditions, it is 

difficult to apply this weighting procedure to available smoke data to determine if smoke opacity 

measured under conditions characteristic of a driving cycle can be used to predict PM. Using 

existing data, it is possible, however, to apply regression models to investigate the potential 

relationship between a combination of conventional smoke tests and PM emissions over an entire 

driving cycle. 

In this paper, the smoke-PM relationship is investigated in order to assess the potential 

for using multiple different smoke opacity test measurements as predictors of PM over an entire 

driving cycle. This was accomplished by developing regression models with PM over the entire 

driving cycle as the dependent variable and various smoke opacity test results as the independent 

variables. The objective was to identify in-use PM-smoke relationships emissions that could 

serve as an analytical basis for converting crude smoke enforcement programs into PM 

enforcement programs. These relationships could be applied in U.S. 11M programs as well as 

those in developing countries. The relationships considered were evaluated not only based on 

the accuracy of the procedure, but also the tradeoffs of cost, safety, and ease of administration. 

2.0 Analysis of Smoke-PM Relationship 

To determine the relationship between smoke opacity and PM, data from the New York 

City Department of Environmental Protection (NYCDEP) were used (NYCDEP, 1996). The 

NYCDEP, West Virginia University, and Colorado School of Mines have the only substantial 

data sets on HDDV PM and smoke opacity emissions. Data from West Virginia University were 

not used because the majority of data were for alternatively fueled heavy-duty vehicles, and fuel 

consumption data were not available. Data from Colorado School of Mines are proprietary and 

were not available. The NYCDEP data are for several types of smoke opacity and PM taken on 

vehicles between model years 1962 -1994. 

2.1 NYCDEP Data 

The usable data from NYCDEP included particulate and smoke opacity measurements 

from 147 diesel buses and 94 heavy-duty diesel trucks. For bus tests conducted after 1986, PM 

was measured for each vehicle on four different cycles: CBD15, N.Y. Bus Cycle-A, N.Y. Bus 

Cycle-B, and the N.Y. Bus Composite Cycle. For the majority of tests prior to 1986, bus data 

were available only for the N.Y. Bus Composite Cycle. Thus, in order to combine the pre-1986 

and post-1986 databases, the data from the N.Y. Bus (NYBUS) cycle were used. The cycle 

average is 6.26 kmlhr over a distance of 1.04 km in 600 sec. For trucks, two cycles were used by 

the NYCDEP: the N.Y. Truck Non-Freeway Cycle and N.Y.-L.A. Non-Freeway Cycle. As with 

the bus databases, there was only one cycle common to all records, the low-speed N.Y. Truck 

Non-Freeway Cycle, so data from this cycle were used for the analysis. The cycle has an average 

speed of 12.19 kmlhr, and covers a distance of3.41 Km in 1015 sec. 

To control for the effects of test cycles variation on emissions, the NYCDEP PM 

measurements in g/mi were normalized to grams per gallon of fuel consumed, based on carbon 

dioxide emissions over the same test cycle. This assumed constant fuel use, which is not realistic. 

However, second by second emissions and fuel use data were not available. Five different smoke 

opacity measurements were made on each bus. These included cruise, idle, wide open throttle 

acceleration [WOT(A)], wide open throttle neutral [WOT(N)], and wide open throttle 

deceleration [WOT(D)]. The WOT(N) is comparable to snap-idle. Smoke opacity test for trucks 
included cruise, idle, and wide open throttle acceleration [WOT(A)]. A discussion of each of 

these tests as well as other common smoke opacity tests is included in the next section. 

2.2 Smoke Opacity Test Description 

The cruise smoke opacity test involves measuring smoke opacity for 5 to 10 seconds as a 

vehicle cruises at 30 mph. This test is most commonly conducted on a dynamometer, but it is 

possible to conduct the test on-road with a sufficiently large test area. Driver variability is a 

slight concern in this test, but the limiting factor is the space necessary for the test. Only nine 

buses and seven trucks in the NYCDEP database had cruise smoke over 1.5% opacity. All of 

these vehicles had high PM emissions in the range of 10 to 20 grams per mile (g/rni). 

The idle test is simply a no load test conducted on a stationary vehicle in neutral. It is 

easily run on the side of the road, but shows a very poor relationship with PM emissions for 

modem vehicles. Only very high PM emitters generally display smoke during idle. In the 

NYCDEP database, the few vehicles with idle smoke opacity above 1% had PM emissions three 

to five times higher than vehicles with idle smoke opacity of 1% or less. For properly 

functioning, contemporary heavy-duty vehicles (model years 1988 to 1998), smoke opacity on 

cruise and idle tests is expected to be 0.5%. 

On the WOT(N) or snap-idle smoke opacity test, the vehicle is put in neutral, and the 

accelerator is depressed rapidly to accelerate to governor speed. There is no additional load on 

the engine, and the test takes only a few seconds. It is favored for liM programs because it is 

easily and safely conducted on the side of the road. As discussed previously, the smoke opacity 

emissions from a snap-idle test are not well correlated with PM. 

The WOT(A) test procedure simulates real-world engine loading. The vehicle is 

accelerated to maximum governor speed while in low gear. This test is not considered practical 

for 11M testing because of the large space or heavy-duty dynamometers required. Even more 

important are safety limitations. Vehicles with poorly maintained brakes or throttles can 

accelerate out of control, so these vehicles are often rejected for dynamometer testing. 

Unfortunately, poorly functioning vehicles are often the same vehicles which are high PM 

emitters. The WOT(D) tests simulates real-world braking, and has the same safety problems as 

the WOT(A) test. 

A sixth procedure, the brake lug down smoke opacity test, was not conducted by the 

NYCDEP. Since the lugdown test measures smoke opacity under a variety of vehicle operating 

conditions, it is the test that would have been most useful for this analysis. While there is much 

existing lugdown data, few vehicles have been tested for both lugdown smoke opacity and PM 

emissions. Lugdown tests, like acceleration tests, are a safety concern for poorly maintained 

vehicles. 

2.3 Limitations 

There are several limitations to using the NYCDEP data set. The NYCDEP data are 

nearly all for city-owned vehicles - primarily buses, but also smaller gross vehicle weight trucks. 

Thus, they are not representative any particular heavy-duty vehicle. There are a disproportionate 

number of low emitters, making up approximately 85% of the data. This is not necessarily 

unrepresentative, since it is generally believe that a few vehicles contribute the majority of 

emissions. It does present a problem, however, when trying to determine relationships between 

PM and smoke opacity. Often the decision whether to fit linear or nonlinear models to the data 

.. 
was based upon only a few points in the moderate to high emitter range. In many cases, 

polynomial regression models appeared appropriate, but the quadratic and cubic terms were 

consistently unnecessary based on t-tests. As a result, this analysis can only be considered 

exploratory in nature, and more high-emitter data would need to be gathered to properly fit the 

models. 

A second limitation is that the lack of data on newer vehicles precluded development of 

relationships for several groups of buses and trucks. Perhaps the most severe limitation is that the 

data were collected over a fifteen year period with few records kept on modifications to the buses. 

Thus there are undefined variations in fuel composition, which has significant impact on the size 

and amount of particles. In analyzing the data, it is only possible to tell the model year of the 

vehicle, not the age of the engine. Thus, it is not possible to estimate the influence of engine 

replacement and vehicle age on the analysis 

2.4 Regression Analysis of NYCDEP Data 

The largest concerns with performing regressions on the NYCDEP smoke opacity and 

PM data were the possible endogenousness of the smoke and PM variables as well as the 

potential multicollinearity of the smoke variables. Endogeneity frequently occurs in econometric 

analysis where the independent and dependent variable are systematically related as in the case 

where price is the independent variable and quantity is the dependent variable. In this case, since 

PM measured over the entire driving cycle is measured in grams with no reference to particle size 

or chemical composition, and smoke opacity in a smoke opacity test is a function of particle size, 

number concentration, and optical properties (which in tum is a function of chemical 

composition), it does not appear that the variables are endogenous. Had an indicator variable 

such as HC data been available and had the data set been more complete, it would have been 

desirable to use two-stage least squares regression to avoid the possibility of endogenous 

variables. The indicator variable (HC) could then have been combined with the endogenous 

variable (smoke opacity) to come up with a proxy variable for smoke opacity. Since no indicator 

variable was available, the endogeneity of smoke and PM was doubtful, and the data set was 

incomplete, the decision was made to apply ordinary least squares regression. 

In terms of multicollinearity, the first step in model development was construction of a 

correlation matrix to determine which variables were closely related. As expected, the various 

WOT tests were very highly correlated to one another. For example, for the pre-1985 model year 

groups, correlation coefficients between different WOT tests typically ranged from .75 to .99. 

Cruise and idle had the lowest correlations with each of the WOT variables (in the .50 and .30 

range respectively). The correlations for peak WOT(N) were the least closely correlated with 

other WOT variables, however, correlations were still high (the correlation coefficient ranged 

from .61 to .71). To avoid potential multicollinearity problems, regressions were first limited to 

single independent variables with WOT(N), WOT(A), cruise and idle as the independent 

variables. An exploratory set of multivariate regressions was then generated by successively 

combining cruise smoke opacity as the first independent variable with each one of the WOT 

smoke opacity measurements as a second independent variable. This procedure was repeated for 

idle smoke opacity as the first independent variable. Unfortunately there were only a small 

number of idle and cruise smoke opacities that indicated more than a negligible amount of smoke. 

Thus, there were not enough data points to draw conclusions from the multivariate regressions. 

The first analysis, determination of a relationship between wide-open neutral WOT(N) 

smoke opacity and PM, was conducted to confirm the commonly held theory that WOT(N) 

smoke opacity and PM are poorly related. It was chosen to use WOT(N) smoke opacity because 

it is very similar to snap-idle smoke opacity tests frequently conducted in 11M programs. If a 

relationship between PM and WOT(N) could be determined, PM emissions could be estimated 
from the vast amount ofWOT(N) smoke data. Since heavy-duty 11M programs focus in trucks as 

well as buses, it would have been preferable to develop the relationships from PM and WOT(N) 

data on both types of vehicles, but NYCDEP did not perform the WOT(N) test on trucks. 

A scatter plot of WOT(N) smoke opacity vs. PM was created for NYCDEP bus data for 

bus model years 1962-1994. The scatter plot reveals no discernable relationship between smoke 

and PM. It appears possible to have high WOT(N) smoke and low PM emissions as well as low 

WOT(N) smoke and high PM. Since different model year vehicles were subject to different 

emission standards, different emission control technology, and different engine design, it was 

hypothesized that the smoke-PM relationship could vary with these factors. Due to the lack of 

vehicle data on the NYCDEP buses, emission standards were the only factors available in 

addition to the smoke opacity of each bus. 

Based on emission standards implementation dates, the data were divided into model year 

groups that were subject to the same standards. New scatter plots ofWOT(N) smoke opacity and 

PM were created for pre-1985, 1985-1987, 1988-1990, 1991-1993, and 1994+ vehicle groups. 

For buses, there were only 15 observations in the 1991-1993 model year group and 4 observations 

in the 1994+ model year group, so no relationships were developed for these data. The 1988-

1990 model year group had 18 vehicles, so only an exploratory relationship was developed. 

Division of the data by model years reveals distinctly different pattern in the smoke-PM 

relationship. Most obvious is the large reduction in PM emissions after 1985. The scatter plot of 

PM vs. smoke opacity for the pre-1985 buses reveals that PM tends to increase with smoke 

opacity, but there are large variations in the PM levels that are recorded at each of the lower 

smoke opacity levels. For both linear and non-linear relationships, diagnostic plots revealed that 

none of the models attempted fit this data. 

Despite the few data points for post-1985 model year vehicles, exploratory relationships 

were developed for WOT(N) smoke opacity and PM. The seven data points for 1990+ vehicles 

were all for vehicles with high PM and high smoke, whereas the data for 1985-1990 vehicles 

were all low to moderate emitters. As a result when the data were all combined into a post-1985 

database, and nonlinear regression was attempted. The coefficient of determination as well as 

residual plots indicated that the models were poorly fit to the data. This is not surprising due to a 

large gap in the data due to there being a multitude of low emitters and only a few high emitters. 

Since it is likely that high emitters have a different relationship between smoke opacity measured 

over smoke opacity tests and PM measured over the full driving cycle, it seems probable that a 

polynomial regression model would fit the data best, but with so few data point on high emitters, 

it was not possible explore this. 

As an alternative to grouping all the post-1985 data together, scatter plots of PM vs. 

WOT(N) smoke opacity for 1985-1987 and 1988-1990 model year buses are presented in Figure 

1 and Figure 2 respectively. The coefficient of determination (R2

) for WOT(N) was .58, 

indicating that a fair amount of the variation in PM data was explained by WOT(N) smoke 

opacity (Table 1 ). A diagnostic plot of residuals vs. fitted values for 1985-1987 buses indicated a 

constancy of error variance and the residuals appeared normally distributed, so these models 

appeared appropriate. The residual plot for 1988-1990 buses, however, showed that the residuals 

may vary in a systematic fashion indicating that the model may not be appropriate for the data set. 

Aside from the lack of fit of the regression models, two important trends appear in the 

scatter plots which confirm that WOT(N) smoke opacity may not be a good indicator of PM 

emissions over the full driving cycle. Many buses with a high smoke opacity reading in the snap-
idle test also had high PM emissions. Some buses, however, exhibited high WOT(N) smoke 

while showing PM emissions only slightly higher than normal. In practice, this means that smoke 

opacity limits must be set high to avoid misidentifying low PM emitters. At the same time, many 

high PM emitters that do not have high smoke during snap-idle are missed. 

The main focus of this paper was to determine if combination of a variety of smoke 

opacity test results would be a strong indicator of PM emissions. It was hypothesized that a 

combination of smoke measurements under full driving cycle conditions (low-load, steady-state 

conditions and transient accelerations) would yield PM-smoke relationships. Since there were 

too few data points with measurable cruise and idle smoke opacity, it was not possible to conduct 

meaningful multivariable regressions. Instead, scatter plots are presented to illustrate potential 

relationships. 

The scatter plot of PM vs. cruise smoke opacity was created for all bus data. All of the 

data are plotted because there were too few vehicles with measurable cruise smoke in each model 

year group. The figure illustrates that all vehicles with detectable smoke opacity (smoke opacity 

greater than or equal to 2%) had higher PM emissions (PM greater than 10 g/mi). Unlike the 

WOT(N) or WOT(A) data, there were not instances where high cruise smoke opacity was 

associated with low PM emissions. This may indicate incorporating smoke opacity tests into on 

road tests would not identify all high PM emitters, and probably would not falsely indicate that a 

vehicle was a high emitter. Thus, the cruise test potentially could be incorporated to current onroad tests along with WOT(N) test, to identify high emitters and reduce the number of low 

emitters falsely identified by the WOT(N) test. 

A similar analysis to the one above was conducted for WOT(A) smoke opacity. 

Although the acceleration smoke opacity test is generally not regarded as practical for on-road 

11M application. As with the WOT(N) smoke opacity, a scatter plot of all truck data reveals no 

apparent relationship between WOT(A) smoke opacity and PM. Again, the data were divided 

according the emission standards that the vehicles were subject to. Since there were only 94 data 

points for trucks, the data were only divided into two categories: pre-1985 and post-1985. In 

general, WOT(A) smoke opacity were higher than WOT(N) measurements. This makes WOT(A) 

an attractive indicator, especially for newer vehicles where smoke opacity is very low. For low 

PM emitters, there were many instances where WOT(N) smoke was below 1%, but for these 

same vehicles, WOT(A) ranged from 1% to 15%. Thus, the WOT(A) appears to be a more 

sensitive indicator of PM. 

The scatter plot of PM vs. WOT(A) data for pre-1985 buses indicates a possible linear 

relationship, while the scatter plot for post-1985 buses indicates a possible curvilinear 

relationship. For the post-1985 buses, t-tests indicated the quadratic and cubic terms in the 

curvilinear fit were unnecessary, so a linear model was fit. There were to few data point to 

confidently develop models, so exploratory models are presented in Table 2. 

The results for truck PM-smoke relationships were very similar to the results for bus 

smoke-PM relationships. A scatter plot of PM vs. WOT(A) smoke opacity reveals that there is no 

discernable relationship between smoke and PM for all of the vehicles in the database. 

The database was then divided into pre-1985 and post-1985 trucks. A scatter plot of PM 

vs. WOT(A) smoke opacity for pre-1985 trucks illustrates that there was a possible non-linear 

relationship between smoke and PM. A polynomial regression model was fit to the data, 

however, and again t-tests indicated the quadratic and cubic terms were not necessary, so a linear 

model was fit (Table 3). 
As with the bus data, there were a few data points for high emitting trucks that did not 

follow the pattern of the rest of the data. This indicates that there is likely a different relationship 

between high and low emitters, and more data needs to be obtained for trucks with high smoke 

opacity to characterize these relationships. Another similarity to the bus smoke analysis is the 

high degree of variability in PM emissions at a single smoke opacity level. For a smoke opacity 

level of 18%, the PM level varied from 9 to 20 g/mi. While the level of variation for WOT(A) 

tests appears less than the variation for WOT(N) tests, the range of PM measurements that are 

seen at each level of smoke opacity is still undesirably large. 

For post-1985 model year trucks, the majority of the data were for trucks between 1985-

1987. The 1988-1990 and the 1991-1993 model year groups had only 7 and 6 observations, 

respectively. Scatter plots reveals no particular relationship nor could regression models be fit to 

the data. 

Similar to the results for buses, a scatter plot of PM vs. cruise smoke opacity for trucks 

reveals that vehicles with non-negligible smoke during cruise had higher PM emissions. Like 

WOT(A) smoke opacity, there were a considerable number of PM emission levels associated with 

a single level of smoke opacity. However, unlike WOT(A) plots, there were no points where 

high cruise smoke opacity was associated with low levels of PM emissions. As with buses, this 

indicates that the cruise test may fail to identify some higher PM emitters, but a vehicle identified 

with high smoke at cruise, is likely a high emitter. Thus, the cruise test has the potential to be 

used to single out gross emitters that the snap test alone would miss. 

If there had been more cruise data points, multivariate relationships would have been 

created to determine if combinations of WOT and cruise tests would be good predictors of PM. 

1988-1990 model year buses and trucks were the only groups of data that had more than three 

cruise measurements above 1%. An exploratory analysis of PM relationships to WOT and cruise 

smoke opacity for these groups indicates that combinations of these tests are potentially good 

predictors of PM. Table 4 contains the regression models for the 1988-1990 buses and trucks. 

3.0 Conclusions 

Increasing evidence of the adverse health effects associated with diesel exhaust have 

prompted action to reduce heavy-duty diesel vehicle emissions. For inspection and maintenance 

programs in developing countries especially, it is desirable to use smoke tests as indicators of PM 

because smoke measurement is more suited to side-of-the-road application, and it is far less 

expensive and dangerous than actual PM measurement. Analysis of data from the New York City 

Department of Environmental Protection yielded only a fair-to-poor relationship between snapidle smoke opacity, the most commonly use on-road smoke test, and PM. Wherever the smoke 

cut-off point was set, a significant number of vehicles were either falsely identified or missed. 

This indicates that snap-idle smoke opacity is not a strong approach for identifying high PM 

emitters. 

The smoke-PM relationship may be improved by conducting a cruise smoke opacity test 

in addition to a WOT test. The few data that exist indicate that vehicles with high cruise smoke 

are consistently high PM emitters. As with the WOT(N) test alone, it is possible to have high PM 

emissions and low cruise smoke opacity. A WOT(A) smoke opacity tests may be superior to the 

WOT(N) test because of lower variation in PM at each level of smoke and better representation of 

lower smoke opacity levels. But its degree of superiority likely does not justify the added cost 
and equipment required to perform the test. A combination of WOT(N) and cruise smoke 

opacities appears to be the most promising identifier of high PM emissions. Exploratory analysis 

showed a combination of cruise and WOT(N) smoke were well correlated with PM. Currently, 

there is too little data to verify this relationship and quantify the impact of incorporating a cruise 

smoke test into 11M programs. 
Figures 

30 

-·a 20 ..._ • OJ) 

'-" 

~ 10 =.. 

0 

0 20 40 60 80 

Snnke (¥lcity (%) 

FIGURE 1 PM vs. WOT(N) Smoke Opacity for 1985-1987 Buses 

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

i 15 ..._ 

~10 

f 5 

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

0 10 20 30 40 50 

SDDke Opacity(%) 

FIGURE 2 PM vs. WOT(N) Smoke Opacity for 1988-1990 Buses 
60.-----------------------~ 

50 

-·

9 40 ....... 

~ 30 

~ 20 ~ 

10 

OT--,--~_,--,--,,--,--,-~ 

0 10 20 30 40 50 60 70 80 

Smoke Opacity(%) 

FIGURE 3 PM vs. WOT(A) Smoke Opacity for Pre-1985 Buses 

60.---------------------~ 

50 

-·a 40 ....... 

~ 30 

:::; 20 ~ 

10 

0 

0 

• 

• 

20 40 60 80 

Smoke Opacity(%) 

FIGURE 4 PM vs. WOT(A) Smoke Opacity for Post-1985 Buses 
25~--------------------~ 

,-... 20 

·a 

-... 15 ~ 

~ 10 

=-- 5 

0+--------,--------,----------l 

0 20 40 60 

Smoke Opacity(%) 

FIGURE 5 PM vs. WOT(A) Smoke Opacity for Pre-1985 Trucks 
• 

Tables 

TABLE 1 Statistics for Linear Regressions on Bus PM Emissions 

1985-1987 Buses: PM= 3.85 + 0.16WOTN 

Variable B SE B 

WOTN 0.157 0.028 

(Constant) 3.848 0.614 

F-stat = 31.9, R2 =.58,# observations= 24 

T 

5.653 

6.268 

1988-1990 Buses: PM= 1.67 + 0.216WOTN 

Variable B SE B 

WOTN 0.216 0.044 

(Constant) 1.668 0.867 

F-stat = 24.5, R2 =.59,# observations= 18 

T 

4.946 

1.924 

Sig T 

0.000 

0.000 

Sig T 

0.000 

0.071 

TABLE 2 Statistics for Regressions on Bus PM Emissions 

Pre-1985 Buses: PM= 3.66 + 1.06WOTA 

Variable B SE B T 

WOTA 1.060 0.073 14.564 

(Constant) 3.657 0.743 4.9241 

F-stat = 212.1, R2 =.68, #observations= 101 

Post-1985 Buses: PM= 3.02 + 0.184WOTA 

Variable B SE B 

WOTA 0.184 0.021 

(Constant) 3.024 0.438 

F-stat = 73.1, R2 =.63, #observations= 44 

T 

8.548 

6.190 

SigT 

0.000 

0.000 

SigT 

0.000 

0.000 

C.I. 

Lower Upper 

0.099 0.214 

2.578 5.118 

C. I. 

Lower Upper 

0.124 0.309 

-0.161 3.497 

C. I. 

Lower Upper 

0.915 1.204 

2.183 5.130 

Lower Upper 

0.140 0.227 

2.142 3.907 
TABLE 3 Statistics for Regression on Pre-1985 Truck PM Emissions 

PM =6.80 + 0.27WOTA 

variable B SE B T 

WOTA 0.270 0.036 7.451 

(constant) 6.797 0.676 10.051 

F-stat = 55.5, R2 = 55.2, #observations= 46 

Sig T 

0.000 

0.000 

C.I. 

Lower Upper 

0.197 0.343 

5.435 8.159 

TABLE 4 Statistics for Multivariable Regressions on 1988-1990 Buses and Trucks 

1988-1990 Buses: PM=0.79+0.13WOTA+2.80C 

Variable B SE B 

WOTA 0.128 0.041 

CRUISE 2.795 0.571 

(Constant) 0.792 0.393 

F-stat = 94.3, R2 =.92, #observations= 18 

T 

3.117 

4.888 

2.016 

SigT 

0.006 

0.000 

0.060 

1988-1990 Model Year Trucks: PM=0.50+3.39C+0.09WOTN 

C. I. 

Variable B SE B T 

WOTN 0.089 0.021 4.093 

CRUISE 3.391 0.355 9.533 

(Constant) 0.499 0.366 1.361 

F-stat = 122.3, R2 =. 94, #observations= 13 

SigT 

0.001 

0.000 

0.192 

C. I. 

Lower Upper 

-0.041 0.216 

1.583 4.008 

0.041 1.626 

Lower Upper 

0.043 0.136 

2.637 4.146 

-0.278 1.277 

• 
.... 

.. 

References 

California Air Resources Board. 1998. "Proposed Identification of Diesel Exhaust as a 

Toxic Air Contaminant", April 22, 1998. 

California Air Resources Board . 1997. "The Heavy-Duty Vehicle Inspection Program 

(HDVIP) and The Periodic Smoke Inspection Program (PSIP)", October 1997. 

Duleep, A. G.. 1997. "Smoke Opacity as an Indicator of Engine and Emissions Control 

Problems." Proceedings World Car Conference, Riverside, CA, January 11-14. 

Escudero-Ortuzar, Juan. 1991. "Traffic and Air Pollution in Santiago, Chile". PTRC 

Seminar on Civilizing Transport; Vol. A; September 1991. 

Jacobs, P. E., D.J. Chernich, and J.D. Kowaiski. 1991. "California's Heavy-Duty 

Vehicle Smoke and Tampering Inspection Program". SAE Paper 911669. 

New York City Department of Environmental Protection. 1996. Heavy-Duty Emissions 

Testing Records. Frost Street Emissions Laboratory, NY. 

National Research Council (1995). Expanding Metropolitan Highways: Implications for 

Air Quality and Energy Use. Transportation Research Board Special Publication 245; 

Washington, DC; 199 5. 

Society of Automotive Engineers. 1994. Surface Vehicle Recommended Practice: SnapAcceleration Smoke Test Procedure for Heavy-Duty Diesel Powered Vehicles. 

World Health Organization. 1996. Diesel Fuel and Exhaust Emissions. International 

Program on Chemical Safety, Geneva. 

Vedal, Sverre. 1997. "Critical Review: Ambient Particles and Health: The Lines that 

Divide. Journal of the Air and Waste Management Association"; Vol. 47; May 1997. 

Weaver, Chris. 1996. Emissions Factors in Thailand and Chile. Report to the World 

Bank. 

World Bank. 1996. Sustainable Transport: Priorities for Policy Reform. 

World Bank. 1998. Air Pollution from Motor Vehicles. 

l'ntroduc:tion 

DBTBRKXNATIOR 0~ BBRBP%TS PROK 

TBB HBAVY btrl'Y VBBICI.a l:NSi'BC'.riOif ARD 

KA:INTBNA!ICB Ji'JtoGJUUI 

Visible smoke lrom hQavy-duty diesel vehicl•• 1• a concs~n to society 5n 

regards to a.iJ: quality. StucUee have confirmed that visible smoke m~r 

contain particles·and gases whieh may cause health problem• includinq lnng 

cancer. Smoke is also visually unpleasant. an4 numerous complaints aJ:~ 

received from citizen• who are concerned about smoking trucks. 

l'O reduce tha amount ot viaible smoke from diesel-powa.:-ecl trucks, th": ~ tn' 

Resout"e•• Boa.:r:d (ARB) has actoptad 1:-he Hftavy-Duty v•hicle Smoka and 1 :>w;··~·ring 

Insp•ction Program (HDVII'). In thia program, heavy-duty diesel v•hlr 1 ,~ •. l 

with smok• opacity rQadinge qrctatar than 55\ (tor vehicles equipped :,: i ·· :, 

pre-1991 enqine•) or 40' (for those vshi.eles with 1991 or newer en~J :.n;-•. '\ are 

tarqett:eci for repairs. As an incantive to repai.r en;rines, opa.ratot •"l .... :. 

tai.ling trucks are fined, howaver, & portion of the tine ilil retu.J.·p,-,tl ;·., 

tho•a owners or opeJ:aters who repait" their vehicle• and provide x~··~il.•' <! as 

pZ:OQf. 

In this mamoz:and.um, the emi.ssl.bns benefits of the HDVIP are calcul~ 1 • .,.,! .-~nd 

discussed. IntortT~ation from the Pre-enforcement proqram, !tad ian' f.' ,.,"~' • • t 

entitled "Keavy Duty VQhic:le Inspection and Maintenanc::e Study" ;u-1··! •.'.d ., 

eollectt!d itl tl'le HDVIP warQ U$8ci to estimaea the benefit9 of the prr.·,,·, i''''. 

some background infortttation on these studie!i a.ce 9iven below. 

saekground 

PU-!:NF'ORCEMENT 

Bta!oz:e implementing the HDVIP, a. preliminary study (called the pt·..--

-anforcement study) was pertorm•d, and data. :f.!!'OIIl this study- waa U""~~J > ., 1 !1"' 

analysis ot the HDVIP. nata were c:olle~ctGid from May 1990 to Nov~'"'~ .... ·.· , .... ~1, 

Attachment 8 
where a total of 3,830 heavy-duty diesel vehicles were randomly selected for 

opac1ty checks at various locations throughout the state. The opacity level 

of each vehicle was measured using a snap 1dle test procedure. 

· Snap 1d1e tests were performed on vehicles with fully warmed engines with 

the wheels chocked. During the actual snap idle test, the engine 1s rapidly accelerated to maximum governor speed. To give the owner/operator of the - vehicle the benefit of the doubt three nclean out" snaps were done to remove 

any excess soot which may have built up while in operation or dur1ny idling. Three t~st snaps were then performed and an average of the two closest 

readings were used as the opacity reading for the vehicle. 

RADIAN STUDY ! 

-·Datl regarding the effect of maintenance on emissions were obtained from a 

study by the Radian Corporation titled the "Heavy-Duty Diesel Vehicl~ 

Inspection and· Maintenance Study~, Revised Draft Final Report VolumA li, 

which was submitted to the ARB on December 7, 1987. Tha study contilln~ct 

several major tasks including quantifying excess emissions due to C.:f!ffiJHment 

malfunctions of heavy-duty diesel vehicles, developing and documentinrJ f\ 

periodic inspection procedure, and a quick roadside smoke opacity tl!l'i: l11 

identify heavy-duty diesel vehicles having excessive smoke emission~. 

The effect of each type of component malfunction on fleet-averagP. rmi$t;fons 

was calculated by multiplying the frequency of each malfunction in ·u!,.. fleet 

by its effect on emissio·ns from vehicles in which a malfunction DC"w-:. The la~est contributors to excess hydrocarbon (HC) and particulate enri·;sit.lll'~· 

(PM} were injector problems, tampering with puff limiters, dirty ~ ~~~ f·l t ters 

and excess oil consumption. Injector p.roblems and o11 consumption l'''·'\T 

projected to remain important in the future. 

The vehicle age groupings in this analysis were chosen to make th" 1::·-:::··~,se 

of the data from the Radian Study. Because of this, the relatiOTi!dt:p between the fa11 ure of. components and em1 ssi ons was analyzed by' vof.:, ': r· .::ge 

as shown in Table 1. ~. 

HDVIP 

From November 25, 1991 to December 3, 1992t out of a total of zoo.nr_ln •!!:fl 

vehicles operating in the state of California, 16,966 (8.49% of "·' l~~~~; 

fleet} were inspected. Vehicles were tested at various weigh st~·~ .. ~• .. !•:. ·"'d 

random roadside testing locations throughout the state using the >!;'~i' idi£J 

test. The owners of the vehicles were cited if smoke from their ti~ ~~was excessive. · 

Because component malfunctions were not identified at the inspectin11 the repair receipts were used to determine the types of malfuncf.i 1 •r:t 

-2-

·: 
repairs made on thes.e vehicles wer• assumed to have been performed to t'emove 

the cause of excessive smoke. Component.ma1function rates wera obt~inecJ by 

examining repa1 r receipts submitted by tru·ck owners between December 23, ., 1991 and November 24, 1992. The CQmponent malfunction rates. at the tint~ of . the snap idle tests were~ therafore, assumed to be the same as the rate of 

component repairs which were determined from the records received as proof of repairing the smoke problem. · 

Data Analysis and Discussion 

Benefits ware obtained when the components that may causa exces!fvA ~moke were repaired. The number of repaired vehicles was determined from. n•p:J·Ir receipts. Infonnation from the Pre-Enforcement Program was used t.o estimate 

the number of vehicles and percent failures. by weight class as shf•Wn In 

Tab, e 1 ~-· .... ~ . . " . . . 

As explained ear:Jier, the component malfunction r!tes for vehicl(l~ 1h.:o~ 

failed the opacity test were obtained frorn the curr~nt HOVIP an·.l : l ,-. , !H"·'•l 

in Table 2. 

-3-
Table 2. Component malfunction rates for vehicles that failed the opactty 

test. . ... _..__ 

No. Type of Malfunction Pre 1984 1984-1987 Post 1987 

(til un (%) ----

1 Timing Retarded 21.56 23.18 17.24 

2 Moderate Injection Problems 42.91 48.09 42.53 

3 Savara Injection Problems 22.75 23.18 16.67 

4 Puff lim1tar Problems 23.19 21.79 16.09 

5 Puff limiter Disabled 9.01 3.46 2.A7 

6 Max Fuel set too high 16.10 12.80 11.49 

7 Clogged Air Filter 32.42 31.14 29.31 

8 Wrong/Worn Turbo 7.39 5.54 1.72 

9 Other Air Problems 1.40 1.04 1.15 

10 Excess 011 Consumption 0.15 0.35 o.o ·- ....... --·~··-···-··· 

_____ ._ ..... __ 

The change in emissions level due to specific malfunctioning componf.mi:s wera 

taken from. the Radian Corporat1on's report mentioned earlier and ;JJ'G shmtn 1 in Table 3. 

Table 3. Change in Emissions Level due to Component Malfunction ---- ....... -:----·-· .. 

No. Type of Malfunction NOx HC PM 

(11 (%) {%} -- -........ -· ... ·-·-

1 Timing Retarded -20 50 50 

2 Moderate Injection Problems .,.s 150 200 

3 Severe Injection Problems -10 500 700 

4 Puff Limiter Problems 0 0 20 

5 Puff Limiter Disabled 10 -20 50 

6 Maximum Fuel Set Too High 0 0 20 

7 Clogged Air Filter 0 0 30 

8 Wrong/Worn Turbo ,.. 0 0 40 

9 Other Air Problems 0 0 40 

10 Excass Oil Consumption 0 300 120 

'-' implies a decrease in ..... -. ·-- .. 

Note: emissions 

The values from Tables 2 and 3, and the equation from the Radi~n ~~~.~.:,~ L·,..·e 

appendix B} were used to calculate the change in NOx, HC, and PM ':•·:·l·~,..-l,·r,·~ 

from baseline emissions for each model-year gt"oup failing the op;v~ii:·., i;:·;(· •. 

(Note that the item numbers, wh1 ch i nd1 cate the type of mal funct.·i n11 u<::···l in 

the equation in the appendix, do not match the item numbers in T;1ld ,. 1. 

S1nce some of the components in the equation are not related to _-:::;H.l!'", t.'~l'!.Y 

were not used to calculate changes in emi ss1ons'). The resu1 t 1ng d·F ~~~q ·i 11 

· em1ss1on le~els are presented in Table 4. 

-4-

., 
Table 4. Hodel year specific change in emissions level for vehicl~!=: tf-J(1t fail the opac,ty test. 

-----------------------------········ 

Emiss1on pre-1984 1984-1987 post-1987 

type (%) (%} (%} - - ...... ·- . --... ...._,._ 

NOx -7.80 -8.93 -6.90 

HC 193.00 207.71 160.24 

PH 322.88 330.00 253.51 

·--····· ... -- .. ..._ I 

Before 'emissions benefits can be calculated, the present emission-; mw~i. he 

defined. The Fleet Average emissions (Favg), as defined 1n Equat.luu 1. r'\re 

the emissions from the fleet without considering any benefits fr·orn UH; 

HDVIP. 

where 

favg • X(l+FR*dTEMl) {1} 

X • the ·em1ss1ons of the fleet if no veh1cles are asst•mnr: ; ·' (:uoke 

excessively. . FR . • failure rate of vehicles (from Table 1}, 

dTEML • Total change in emissions level (from Table 4), awl 

Favg =the emissions of the heavy duty d1esel fleet consil:i '>t·• ;·{' 

Qoth smok1ng and non smoking vehicles. 

X can be calculated using Equation 2. 

X a Favg*{l/(l+FR*dTEML)) {2) 

For the purposes of this analysis, the fraction by which t_he flJ•"' · .. · : :;q 

erniss1ons differ from emissions of the fleet without smoking vet.~-",··· :·:t 

be referred to as the heavy duty control factor (HDCF). "{he Hon · · obtained by taking the failur.a·rates from Table 1 and weighting :_;.,· . ·: · ~.,e 

change in emissions in Table 4. Equation 3 was used to obtain tl ,, · ·.--·:' ·lng 

HDCF's shown in Table 5. 

HDCF ~ {1/(l+FR*dTEML)} 

-5-

(3) 

... ·, 

·' 

. I 

•j. 

' i 

/ 
Table 6. Heavy Duty Control Factors. 

Weight 

Class 

~-

----·· 

MHO 

' 

LHD 

NOx 

HC 

PM 

NOx 

HC 

PM 

NOx 

HC 

PM 

Pre 1984 1984-87 

1. 044 :.:';; ' 1.028 .. 0.492 0.613 

0.367. ('- ;. . 0.499 

1.022 1.012 

0.656 0.787 

0.533 0.700 

1.016 1.009 

0.721 0.828 

0.608 -0 .1S2 ---

I_. I \ . . , ,. '' ' 

': . ' ' 

'I 

Post 1988 

1.015 ,'/ /(.J(./i 0.745 ,_ 

0.649 

1.006 

0.880 

0.822 

1.002 

0.949 

0 .. 922 

·-··-···----

Table 5 displays "the potential reduction of HC and CO-and increa$P. ·in tiOx 

emissions •f all required repairs ware made on all vehicles failiny the 

smoke opac1ty test 1n the fleet. 

Calculation of Emi'ss1on Benefits from HDVJP 

Presently, in the HDVIP, only a portion of the heavy-duty diesel fle~t t~ 

inspected for smoke opacity, therefore, only a portion of the fle~t. oht~.1ned 

emissions benefits from current HDVIP. The following equation t~::..~ ~~~'?rf to , modify the emission rates to account for HDVIP for calendar yeal· Jq:~?: 

Fadj = Favg-A{%targetted""a~*(HOCF - 1) + 1} (4) 

Fadj ~ Basic emission rate which includes HDVIP data 

Favg = fleet emi ss1on rate which includes smoking and non- <=r~ilk:i P<:r 

vehicles 

,;targetted • the percent~ge of vehicles inspected un·der HDV.i.P 

a • adjustment factor (See assumptions in Append1x A .. ) 

b ~ percent of vehicles repaired 

To calculate the ·benefits of the HDVIP for the first year of thP. pn~!p·;~"'­

assum1ng that the 8. 49% of the fleet was target ted i o year 1, Ef4'A'l u on ·1 w~s 

used to modify basic emission rates present in the PC version of HlFJ\ClF, 

The %targetted was 8.49% •ta" was o.st and "b" was 74. 7%. The P~''o~nt (Jf 

vehicles repaired was determined using the number of repair rece·ipl ~­ submitted within a year of citation during the perfod from Noven1b~·4 7.S~ J9n 

to October 16, 1993. The statewide estimates of emission reductin•:-5 ir- t.Qns 

per day (tpd) and% reduct;on from present emission values are $hn\·m hl 

Table 6. 

. I 

. . ' ~ ·' . 

··; I 
Note: The negative sign (-) indicates an increase in emissions.--···-·- ..... 

With 8.4~ of the vehicles targetted, emission levels for HC and l'fi ;~; r:. 

estimated to decreased by 1..1% and 1.6S respectively and NOx emt~'·:lr•;•:: :.,,·s 

estimated to increased by 0.08% due to the HDVIP. 

As shown in Table 6, if the entire HDD fleet is targetted, the t·r·•.irr·· :.~ ,,:., in 

HC and PM emissions is predicti!d to be 13.0% and 18.9" res·pectiv .,·:J -~ '.: l.;,e 

increase in NOx emissions will be 0.91. 

Table 7 contains emission estimates for the second year of the 111'; .. ,~, i·,_) 

correction factor "a .. is assumed to equal 1.0. In the second a·,J·I ; ·• · ···.···ng 

years, if 100~ of the fleet is targetted, then emission levels 1 ····~ :: · · ,. ·. 

are predicted to be 24.5~ for HC and 36.5% for PM. NOx emissior.· · · predicted to increase by 1.8%. These changes would only take p·i. ·. ;..;:1% 

of the fleet were targetted in the first year as well. 

-7-
~ 

Table 7. EMFAC Emission Estimates in TPD for 1993. 

---~ .. ·--.. ~-··---

Weight Reduction· %reduction Reduction %reduction 

Class for 8.4~ for 8.49% for 100% for 100% 

tar~etted ( pd) ta.rgetted targetted (tpd) target ted 

.__....... ......... -··· ----- HHD 

HC 1.1679 2.145% 13.7567 2S.2.S9% 

NOx -0.8447 -0.155,. -9.9492 -1..829% 

PM 1.8747 3.157% 22.0812 37. J~e'; ... I 

MHO 

HC 0.0470 1.187" 0.5531 13,.913-!~~ 

NOx -0.0255 -0.069% ·0.3007 -O.f\10% 

PM 0.0648 Z.0341 0.7637 23.95()~ 

LHO 

HC ·0.0007 0.789% 0.0083 9. 2H'l';~ 

NOx -0.0003 -0.045~ ·0.0039 -0. &2C!?~ 

PM 0.0010 1.497fr 0.0113 17 .(;Jii% 

Total 

HC 1.2156 2.07~ 14.3182 24. 4i(;~ 

NOX. -0.8705 -0.150f. -10.2538 1 'T(' >'·• -./.) .. '/ ... 

PM 1.9405 3.0981 22.8563 36 4 f~'J','' ... . ... 

Rote: The negative sign (-) indicates an increase in emissioni~ · .. 

Incorporation of HDYIP tnto EMFAC 

To incorporate the HOVIP benefits 1nto EMFAC, Equation 4 should h· •;·~·:·~. 

The •%targetted" and "b" values depend on the nature and scope or ! ... " 

program and were calculated for calendar year 1992 througtl 1994. ~. 1 '":: ',;;•ar 

of 1993, the. HOVIP was suspended, therefore, no benefits would ·IJ'.:: ,,.- ,;;···"; . for the heavy-duty d1 esel f1 eet for years beyond 1994. Table 8 1 n, : · · ... · i:he 

"a", "%targetted" and "b" values that should be used for each c;1;, ·;.:,-

year.· The "a• values are also included for future years when th·) : ... -,,,, :·;·,y be implemented again. 

-8-
• { 

Table B. The •a" values for each year to be used in Equation 4. 

: 

· Year .. a .. ~targetted •b• 

------ 1992 o.s 8.49 74.7 

1993 1.0 8.49 74.7 

1994 o.s 8.49 74.7 

1995 NA 0.00 NA 

Year 1 0.5 to be determined later 

Year 2 1.0 • ... • •• Year i 1.0 • 

• • • Year n+l 0.5 n 

··-- -· .............. -.,._...,..._ 

Year 1 is the fir.st yea~ the program 1s implemented, again. Year i 

represents .. any year after the f1rst year of impl ementat1on of the progr-:Jnt. 

Year n+l r~presents the year after the program 1s terminated. 

Reconuandations 

In orde\'" to further improve the estimate of the emissions banefi t fn~m 

HDVIP, the following suggestions should be pursued: 

1. Randomly ~ample, us1ng the snap idle test, those vehicles wh·id• 'rn~n~ 

repaired to see how much the emissions were reduced to 1) ensurP. l·h;at l.ho 

repair performed reduced opacity readings to the acceptable level, ;ti'.i ;n update the emissions impact due to component failure • 

. 2. Track the number of vehicles which pass the opacity test, ev~n 1.> .. :~~ 

which pass the v1sua1 screening, to obtain actual failure rates. 

3. Estimate the emissions effect of component malfunctio~s for ''N·">r· .Pftl1 

vehicles. The Radian report only included analyses for up to 19~Hl !;),.,,~,)' 

year vehicles. 

-9- ' i 

.I 
APPENDIX A 

ASSUMPTIONS 

Because very little data ex;sts on the number of the vehicles which are 

repaired to compliance and on how long they remain 1n compliance, the 

following assumptions were made in deriving the benefits of the UOVJP: 

1.) The current HOVIP fleet composition is similar to the fleet composition encountered in the pre-enforcement program 1n regards to the popul ath1~1 

distribution by model year and we1ght category. 

2.) All repairs on vehicles are assumed to reduce or increase emi ~~ il.ms t.Jy the amount estimated through the use of the Radt an equation (Append h o}. 

" ' 

3.) Repairs performed to clear c1tattons are effective for at l~ac;t nno 

year.. Figure 1 shows that most of the repairs )lara performed within J.no 

days of the citation. 

4.) The adjustment factor •a• is assumed to be 0.5 for the f1rsl .Y~?ar, 

because vehicles.repaired in first month accrued benefits for thr.- t..,.i'lol~ .vear 

wh11e vehi,cles that wer-e repaired in the 12th month accrued negl i9ihl1! 

benefits. The rate at which vehicles -.tere target ted in the progr?nt 1:1~, :~ not 

constant with time {See Figura 2) but are assumed to become more ·: 1. {•.h1 {: ;).s 

the program became· more established. The number of tests per d~.v \·11'1:-; 

assumed to remain constant. 

5.) Based on monthly Heavy Duty Diesel Roads1da status report ( s"'r1 r ·i ~~~·~·,., 

3), the HDVIP was assumed to have no detarrent effects, since th".Y·-· l ~ r.11 

statistically .supportable trend in the data. 

-10-
I 

• ... i 

" APPENDIXB 

Equation used to calculate eff'ccts or ramperlnc and malmaintenaDc:e-related de&cts on emissions .. 

GrouP* 

1. lnjdoia IDn1D& advaneed 

2. JDJec:doa ttmilig rebtded 

. U. Electi'ODh:a &iled . 16. Blee1roDb tmDprncl 

19. BGR Disabled 

.. 3. Minor hajeetlon problems 

4. Modente iqjectiw problems 

6. Pufflim.ir.er mls-set 

7. PuffliJ:nitllr ~led 

8. Maximum fUel hlch 

9. clogged air ft1ter 

10. Wroq/Wom. Turbo 

11. Intercooler cloaed 

12. Other aJr problems 

17. Catalytic convetter remove<! 

lS. Trap removed/disabled 

s. Severe JJU~on problems 

13. Mechanleal failure 

14. !xcess oil comumptiou 

Source: Radian report. 

Caleulationt 

X 

(1.0 + b.EF3 + AEF.t) 

X 

X 

X 

(l.O+~g) 

X 

(1.0 + AEF11) .... 

X 

(l.O+~l:z) 

(1.0 + ~17 + &Efl&)]- 1.0 

+6Bl's 

+dEFu 
a 

.j 

lOt 

lSO 

200 

'0 1$0 

i 

;::1 

so 

Figure 1. Lengtla of time taken to receive repair receipts. 

' 

MaD •61.85 

ModiaB •47 

•\#\' . . - yQlJl, '\ • - .... ,_, ' .. , .... '""l:--- .. ' ...... .... ; ::,.. __ ,.. __ or•·-' ' •'··-••-• 0 

:) ·:::t) !iJO 

.. -, -........ -- . .: . : · ...... -·., .• .:.- ....... tt .. .,. ., -· - ; ····'"' ·· .;,,.; ·• •· .l •.•. ! •. j_;.,;.. ,t.,. .• .;.l'; if.la • j 
Figure 2.. Average snap idle tests performed per day during the fint year or t

3S.OO 

30.00 

i lS.OO 

l 

I'll 2t.OO 

t . 

ls.IO 

10.00 

5.00 

G.OO 

I 5/11-922 li/12-6130 7/15·7131 Ill .a/IS ICVI0-11
Figure 3. Pereentage of snap idle test :failures. 

Rl•0.30662 

40.00 

35.00 30.00 

E 2s.oo 

.:! 

... 

: 

- 20.00 n 

foe 

a. 

.. 

Q lS.OO Ill 

10.00 

s.oo 

0.00 

.... #'.1.·. :C/1"1-lm 51\ !-51.!2 6112.-6130 a/31·9/ll 9/14-101'9 10110.1111 

:. ..