# TECHNICAL SUPPORT DOCUMENT

CARBON MONOXIDE REDESIGNATION REQUEST AND MAINTENANCE PLAN FOR THE DENVER METROPOLITAN AREA

January 4 , 2000 Co lorado Department of Public Health & 

### Environment Air Pollution Control Division

Technical Services Program 4300 Cherry Creek Drive South Denver, Colorado 80246Technical Support Document Carbon Monoxide Redesignation Request and Maintenance Plan for the Denver Metropolitan Area

CDPHEIAPCD /Technical Services Program January 4, 2000 iiTechnical Support Document Carbon Monoxide R edesignation R equest and Maintenance Planfor the Denver Metropolitan Area 

# Table of Contents 1. INTRODUCTION .............................................................................................................................................. ! I.I. BACKGROUND ................................................................ . .. ... ........... . . .... .......... ... .............................................. I I. I. I. Nationa l Ambient Air Quality Standards for Carbon Monoxide ............. . .. ... .... .. ..... ........... .. .. . . ............ 1 1.1 . 2. Health Effects of Carbon Monoxide.. .... .. .... .......................................................... .. .... . .......... .. .......... ... .I 1. i .3. Denver Carbon Monoxide Area Designation History....................... . ... .............. . ... ................ . . . ............ i I. i .4. Denver Metropolitan Attainment /

Maintenance Area................................. ... ......... .. .... .. ...... ..... ... .......... 2 i . 1. 5. Topography, Climate, andAir Quality Meteorology .... .. . ... . ........................................... .. .......... ... ....... .4 1 .2. REQUIREMENTS FOR REDESIGNATION ......... .. ... . .......... ....................... .............................................................

### 7 i . 2. 1. Attainment of the Standard .. . .................... .. ......... .... .... .. ........ .. ... .. . ... . .. ... . ......... .. ......... . ......................... 7 1. 2. 2. State Implementation Plan Approval .... .. ... . ................. . ............. . ............ . .................................. .. .......... 7 1.2. 3. Improvement in Air Quality Due to Permanent and Enforceable Emissions Reductions .. ........... . ........ 7 i .2.4. CAA Section 110 and Part D Requirements .......................................................................................... 7 1.2. 5. Maintenance Plan . . ............. .... .. . .............. . ........ . . . ....... . ........... ..... ..... ... . ... . . . ....... .. .. . .. . ...... .. ... . ... ..... .. . . .... 7 2. EMISSION INVENTORIES .............................................................................................................................8 2.1. EMISSION INVENTORIES USED IN THE URBAN AIRSHED MODEL ................. . ......... . ..........................................8 2.2. DEMOGRAPl-DC AND TRANSPORTATION DATA ....... ... .... . ............... .. ................... ......... ....... .. ........... ...... ...........9 2.3. RESIDENTIAL WOODBURNING ........................................................................................................................ 10 2. 3. i. Fireplaces emissions calculations (grams /household) ....................... . ................................................ 10 2. 3. 2. 2006 and 2013 Stove Device Emission Calculations ...... .... .............................. . ................... .. . .... ........ i2 2.4. ON-ROAD MOBILE SOURCES ........................................... .. ............................................................................. 15 2. 4.1. Control Strategy Recommendations............................ .. ....................... . .... . ............ ..... ...... .. ..... ........ .... 15 2.4. 2. Vehicle Miles Traveled (VMT) ...... ...... . . ..... . .... .. .. ... ........ ... .......... . .. . ..... ..... ....... ... .... .. ...... . . .......... .. . .... . . i 5 2.4. 3. Mobile5b Emission Factor Modeling ....... . ..... .. .................. .. .. . . . .......... . .. .. ... ....... . ... . . .... ..... . ... ... .... ...... 

### 16 2. 4. 4. NLEVCredit Estimate............... .. .... ........ .. . ..... . ............................. . ...... .. ....... . ... . .... .... ............... ..... ...... i7 2.4.5. RSD Program........................... . ... . . . ... . .. .. . ... ......... . .................... . ... . .... ... .. ... . ..... ............ ...... ...... . ....... .... i 7 2. 4. 6. Oxygenated Fuel Program....................... . . . . .. .. . . ... . .. .. . ... . . . . .. .. ... . . . . . . . . . . ..... .. .. . . ........... ..... ... . . ..... .. .. . .... ... 20 2.4. 7. Mobile5b Scenario Inputs ............................... . . . ........................................ .. ........ . ... . . ... ... .... .. . ...... .. . ... .20 2.4. 8. Carbon Monoxide Emission Factors for 2006 and 2013 ..................................................................... 20 2.4. 9. Emission Inventory Calculations ............ . .. .. ..... .. . .. .. . . . ... . ... .. ... . ......................................... ........ . . ......... 20 2.5. NON-ROAD MOBILE SOURCES AND AIRPORTS ....................................... . ........ . ...... . ............... .... ....................21 2. 5. i . Revised Emissions Estimates for Denver international Airport .................................... .. ......... .... ....... 21 2.6. POINT SOURCES ................................................ . ............................................................................................24 2. 6.1. Point Source Growth in 2006 and 20i3......... . ... . ...................... .. .. .. .......................... .. ...... ............... .... 25 2.7. TEMPORAL DISTRIBUTION OF DAILY EMISSIONS ... ........................................................................................26 3. AIR QUALITY MODELING METHODOLOGY .......................................................................................27 3 . 1 . OVERVIEW OF MODELING PROCESS ........... ... . ... ................. . ... ... ............... ... ............... ... ..... . ...... ........ .. ..... ......27 3.2. MODEL SELECTION ........................................................................................................................................27 3.3. FLOW CHART OF AIR QUALITY MODELING PROCESS .....................................................................................28 3.4. EPISODE SELECTION ................................................................................................................ .... .... .............. .30 3.5. METEOROLOGICAL D ESCRIPTION OF MODELING EPISODES .......................................................................... .31 3. 5. i . Modeling Episode Selection for Maintenance Plan ............................. . ..... . .. .. ................. ............. ....... 3 i 3. 5. 2. Meteorological Cond itions on December 5, i988

- "High" Episode . .. ............ .. . ...... . . . ...................... .. 32 3. 5. 3. Meteorological Conditions on January i5, i988- "Second-High" Episode ... .... ... .............. ... . .. ......... 32 3 .6. MODELING DOMAIN ....... ......................... . . . ...................................... . . ....... .. ................... ... .... . ... ................... ..32 3.7. DIAGNOSTIC WIND MODEL (DWM) .......................... . ... ... ... ...... .. ... . ..... ...... .... .................... ..... ... . ..... . ...... ......35 3.8. URBAN AIRSHED MODEL (UAM) SETUP AND APPLICATION ............................................ ..................... . ....... .36 3. 8. i . Simulation Start and End Times (SIMCONTROL) ................................ .... ...... . . ........... ...... .. .... . . .. ....... 36 3. 8. 2. initial Conditions (AiRQUALJTY) ........... ... .................................................... .. ..... . ............................. 

### 36 3. 8. 3. Other UAMpreprocessors ...................................................................................... . ................ .... ........ 38 3.9 . CAL3QHC MODEL SETUP AND APPLICATION ............... ..... ................ ..... .... . .................... . ...................... .....39 3. 9. 1. Intersection Selection ............................... .. .... . .. ....................... ................. . .... . ............. . ....................... 39 CDPHFJAPCD /Technical Services Program January 4, 2000 iiiTechnical Suppo r t D ocument Carbon Monoxide R edesignation Request and Maintenance P l anfor t he Denver M et

ropolitan Ar ea 3. 9. 2. CAL3 QHC Inp ut data ...... . ... . .. . . .. . ... . . . ... .. .......... . . .... . .............. . .... .. ... . ............ . .. . . ........... . ..... .. ... . .. . ........ 45 3. 9. 3. Receptor Locations . . . ...................... . . . ... . . .. ..... . . . .. . . .. . .... . . . . . ... . . ... ... . . . ... . . .. . . . . . .... .... . . . . . .. . . . . . ... . . . . . .. ... . . . . . . .. 45 3. 9.4. Ve hicle E miss ion Rates ... .. ... .. .. ... ....... . . . . .... . .... . . . . .. . ........................ . . . ............. . ......... . .. .. ....... . . .. . .. .. . ...... 46 3. 9.5. Sc reening Procedures . . . .. . ......... . . ... . . .. ... . ................ . ............ .. ... .. ...... . ............... . ... .. . .. .............. . . . .......... 46 3.9. 6. Refined Mode ling Procedures... .. .. . . . . . . . ... . .... . . .. . .. .. .. ....... . . ... . . ... . ........ . ..... . .... .. . ... ....... . ... . ........ . ............. 46 3. 9. 7. Trea tment of Calms .. ... .. ............. . .... ... ..... .. ........ .. .. . . ... . . ... ...... .. . .. .. ........ . . .... . ..... . ... .. .. . . .... . ..... . ...... ........ . 4 7 3 . 10. M O D

EL PERFORMANCE EVALUAT I ON .. . . . ...... .. .. . .... . ... . . .. .. . . ... . ........ . .. . .... .. ........... . ... .. . . . . .......... . ... .. .. . . . .. . ... .48 3. 1 0.1. Statistical Pe r formance Measures Required b y EPA ....... . ... .... ... . . . . . . . . . .. ... .. . . . . . .. . . .. .......... . . ... . . . . .. .. ...... .49 3. 10. 2. Add itiona l Performance Measures . .. ............. .... .. . .. . ........... .. .. ... . . . .... . .. . ....... . ...... .. . .. . .... . . .... . . . ... .. . .. ... . .. 

### 53 3. 10. 3. Gra phical Meas ures..... . ...................................... . . . ......... . .. . . . .. . ... ... .. . . . . . .. . . . .. . . .... . . . ... . .. . . .. . . . . . . . . .. . .. . .. . ... .55 3. 10.4. Se lection of CO Mo nitorsfor Use in the Perfo rmance Eva luation Req uired b y EPA . .. . . . .. .... .. .. .. .. . . . . .55 3. 10. 5. " High " E p isode Performance Measu r es ....... .. .. .... ......... . ... ... ........ .... .............. . .. ... . ...... . ..... .. .... . . ...... . .. 63 4. MODELING-BASED MAINTE NANCE DEMONSTRATION .... . ......................... . .............. . ............ . ..... . .73 4. 1 . D ES I GN CONCENTRATIONS . .. ....... . .. .. ..... .. .................. . . . ............. . . .. . . . . . ... . .......... . .... . . ......... . ..... . . . .... .. . ... . ..... . . . .. 7 3 4. 2 . CONTR OL STRATEGY ASSUMPTIONS .. . .. .. ........ . .... . . . . . ..... . . ... . .. .... . .. . .. . ...... . ............ . . . . .. ......... . .. . . .... . ..... . ..... . .... . 74 4.3. UAM AND C AL3 QHC RESULTS .... . ... . ... . .. . ... . . . .. ... .. . . .. .. . . .. .... . . . . ......... . .... .. . .. . . ... ..... .. . . . . ... . . . ..... ..... . . . . . .... ... .. . . . 7 6 4.4. 2006 AN D 2013 B UDGET RELATED EMJSS I ON INVENTORl ES ... ... .... ... .. ... . . . ... ......... ... .. . ....... . ..... . .. . . .. . . .. .. .. .......7 7 5. MONITORING-BASED ATTAINMENT DEMONSTRATION ................ . ................. . .... . . . ..... . ........... . ....85 5. I. DENVER AREA HI STO Rl CAL PERSPECTIVE .. . .. . ...... .... . .... ....... .. ......... .. . .... . .. ... . .. .. .. . . . . ..... . ... . .. .. . ..... . .. ... . . . .... . .... 85 5.2. C ARBON MONOX ID EMONITORlNG NETWORK .. . .... .. ... . . ...... . .... ... .... ........... . . . . . . . .... .. .. .. ... . . .. .. .... . . . . .. .... . ........ . . .8 5 5.3. M ON I TOR1NG -8 ASED ATTAINMENT D EMONSTRATI ON . . .. ..... ... .. ..... .. ... . ... . ... . ... .. . .. .. .. .. . . ... . .. .. . .. ... . . . . .. ..... . .... .... 8 7 5.4. Q UALITY ASSURANCE PROGRAM .... . ...... . .. . ....... ...... . . . ... .. ... . .. . ......... .. .. ...... . ...... ..... . . . .. . .. .. . .. .. ... . ... .. . . ... .. . . . . .... . .96 5. 4. 1. I nter nal Quality Assurance Programs . ....... .. ..... . . ... . .... . .... .. ... . . . . ... ..... .. .................. .. ... . ........................ 96 5. 4. 2. &ternal Quality Ass ur ance Programs ... ... . ... . ...... . ... ... .. .. .... .. . .... .. .. ......... . ... . . . . . . ... ... ....... .... .. . . ... .... . ..... 98 5.4. 3. Results of t he Denver Me tropolitan Area Prec ision and Accuracy Program .... . . ...... ... .... ..... . . . .. .. .. . . ... 98 6 . DATA ACCESS.............••.................. . ......... .• . •. ...• .... . .... . .......... .. . •. ... . .• .... . ............... . . . .... . .. . ... . ........... . ............ 105 7. REFERENCES ........................ . .....•..............•... . . . ... .. ..... .... ..... .... . .....••. . .. ... . . . ..... .. ... . .. .... .. . . ... ... •.• .. . . ... .... . ... .. ... 107 8. ENDNOTES (AS REFERENCED IN THE APPROVED DENVER " CO SIP TECHNICAL SUPPORT DOCUMENT " ) ............... . ........................................................................................................................................ 109 I NDEX ... .... . . ... . .................. . ......... . ... . ..... . ... •....... . ........................... .. .. . .......... . . . ........ .. ... . .. . ... . .. . ................ . ....... .. .. . .... 111 APPENDIX A - MOBILE SOURCE EMISSIONS MODELING: VMT SUMMARIES BY DISPERSION MODELING DOMAIN AND NONATTAINMENT AREA DOMAIN ... . ... . . .... •. ....... .. ...... . ............................... 113 APPENDIX B - MOBILE SOURCE EMISSIONS MODELING: MOBILE5B INPUT/OUTP UT AND FORTRAN ALGORITHM FOR NLEV CREDIT ESTIMATE .. . .......................... . ........................................... 127 APPENDIX C - MOBILE SOURCE EMISSIONS MODELING: EMISSION FACTORS . . . .. .... ... ......... . . .. ...251 APPENDIX D - MOBILE SOURCE EMISSIONS MODELING: EMISSION ESTIMATES ................ . .......255 APPENDIX E - URBAN AIRSHED MODELING: HIGH EPISODE 2006 RESULTS (RUN H) ... ......... . .....269 APPENDIX F

- URBAN AIRSHED MODELING: HIGH EPISODE 2012 RES ULTS (RUN L) ...................328 APPENDIX G

- URBAN AIRSHED MODELING: HIGH EPISODE 2013 RESULTS (RUN 0) . . ........ . .. . .... 388 APPENDIX H

- CAL3QHC MODELING ........... . ..... . . . ....... . .... ... . . .... . .. . ..................... . .........................................448 APPENDIX I - FEDERAL REGISTER: MARCH 10, 1997 (VOLUME 62, NUMBER 46).... •.. .. . . ... . ...... . .. . ....535 C

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! Technical Se rvices Program Janua ry 4, 2000 ivTechnical Support Document Carbon Monoxide Redesignation Request and Maintenance Planfor the Denver Metropolitan Area APPENDIX J - TEMPORAL DISTRIBUTION OF EMISSIONS ............ . . ..... ..... ... ... ... ....................................553 APPENDIX K

- SECTION 110 OF THE CLEAN AIR ACT .............................................................................559 APPENDIX L

- DENVER INTERNATIONAL AIRPORT EMISSION INVENTORY ..................................571 APPENDIX M

- ANALYSIS OF THE PROBABILITY OF A CARBON MONOXIDE EXCEEDANCE IN DENVER DURING THE FIRST WEEK OF FEBRUARY FOR THE YEARS 2002 THROUGH 2013 AND TWO POSSIBLE LEVELS OF OXYGENATE IN AUTOMOTIVE FUELS BASED ON HISTORICAL CARBON MONOXIDE DATA FOR 1975THROUGH1994 ....................................................................... .... ..575 APPENDIX N-TRANSPORTATION MODELING DOCUMENTATION ....................................................581

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# List of Tables Table 1. Emission inventories for the Denver carbon monoxide Urban Airshed Modeling. Cl) . . .... 8 Table 2. Demographic data used to develop emission inventories (modeling domain) . ....... . .. . . .. .. 9 Table 3. 2006/2013 Residential woodbuming carbon monoxide emission inventory.. . ........ .. .. . .. 10 Table 4 . 2006 Fireplace emission rate variables/results .... . .. .. . . .... .. .. . .. .. ............ . ... . .................... . . 11 Table 5. 2013 Fireplace emission rate variables/results ............................................................. . . 11 Table 6. 2006 stove device calculations ........ . ......................... . ..... . ........... . ...... . .. ... .... .. ............... 13 Table 7. 2013 stove device calculations ....... . ............ . ........... .. ..... . . .. .. . . .. ....... . . .. ..... . ... .. ........ .. ... . . 13 Table 8. 2006 Stove emission calculation variables/results . . . .. .... .. .... . ............. . .......... . ................. 14 Table 9. 2013 Stove emission calculation variables/results . . ....... . ..... . .................. . ....................... 14 Table 10 . Daily VMT totals in the Denver-Boulder carbon monox ide Denver-Boulder Carbon Monoxide Nonattainment Area........... .. .... . .. . ................ . ........ . ..... .. ........ . . ... .... .. .. .. ......... . ...... 15 Table 11 . VMT totals in the Denver-Boulder carbon monoxide Urban Airshed Modeling domain .... . .. . ....................................... .. ..... . ..................................................... . .......... . ..... . .. . . 16 Table 12. Input file in the EPA RSD model to generate the 80% credit file ... .. ..... . .. .. . . .... . .... .. .. .. 18 Table 13. Data used in model year calculations ofeligible vehicles ... . .. . ... . .. .. . . ... ..... . .. .. . ...... .. .. .. . 19 Table 14 . On-road mobile source emission estimates in tons per day (tpd) in the Denver-Boulder carbon monoxide Urban Airshed Modeling domain ... . . .... .. .. . . .. ..... .. .. . . . ... .. .. . .... .. .. . ....... . ...... 20 Table 15 . On-road mobile source emission estimates in tons per day (tpd) in the Denver-Boulder Carbon Monoxide Nonattainment Area..... .. .... .. .... . .... .. . . .. . . ... . . .... .. .......... . .... .. ... ... .......... . ... . . 20 Table 16. Revised emission inventory for Denver International Airport....... .. .... .. . . ... .. ...... . . .. ... .. 23 Table 17. Ranking ofDenver carbon monoxide episodes

- 1988 through 1991

- as determined for the approved CO SIP............................................................... . .......... . ..... . ..... . .... . .. .. ... .. .. 31 Table 18. Denver metropolitan area Urban Airshed Modeling Domain ............. .. ...... . ...... . ...... . .. 33 Table 19. Comparison of maximum I-hour and 8-hour average carbon monoxide data at CAMP and Speer and Auraria between 1993 and 1999.. . ... . ..... . .... .. ........ . ...................... .. ...... . ..... ... . 42 Table 20 . Carbon monoxide monitoring sites used in the UAM and CAL3QHC modeling study for the Denver CO SIP ............ . .... .. ........... .. .. . ..... . .......... . . . .... .. .... .. ..... . ... . . .. .. . .. .. .. .. ......... .. .. .. . 57 Table 21. EPA's recommended statistical performance measures for the "high" episode ...... . .. .. . 65 Table 22. Comparison of modeled vs. observed CO 8-hour average concentrations for the "high" episode (Run A)

- December 5 , 1988 ..... .. . .. . .. . . .. ..... .. .... .. ............. .. ................. . .... . ......... . ..... 65 Table 23. Comparison of approved emission budgets with emissions estimates that would result from the Denver carbon monoxide maintenance plan ................. . ....... . .. .. . . ......... .. ...... . . .. ..... 77 Table 24. Combined UAM and CAL3QHC estimates for "high" episode

- Run H : Enhanced Inspection/Maintenance 240 with new vehicles exempted for their first four years; 1.5% oxygenated gasoline ; evaluation of up to 80% ofthe fleet with Remote Sensing Devices (80% RSD) ..... . ....... . ........ . ................... . ........... .. ........... . .. . .... .. ........................................ . ... . .. 78 Table 25. Combined UAM and CAL3QHC estimates for "high" episode

- Run L: Enhanced Inspection/Maintenance 240 with new vehicles exempted for their first four years ; 1.5% oxygenated gasoline ; evaluation of up to 80% ofthe fleet with Remote Sensing Devices (80% RSD) ... . ..... . ............ . ....... . ........... . .... .. ..... .. ........... .. . . .. .... .. . . ... ........ . ...... . ..... .. ......... . .... . .. 80 Table 26. Combined UAM and CAL3QHC estimates for "high" episode

- Run 

### 0: Enhanced Inspection/Maintenance 240 with new vehicles exempted for their first four years ; 1.7% oxygenated gasoline ; evaluation of up to 80% of the fleet with Remote Sensing Devices (80% RSD) ...... . .................. . .... .. .......... . .. .... ..... .. ........... .. .... .. ............... . . . ...... .. .. .... .. .. .. ... . . .. .. .. 82 Table 27. 1997 Carbon monox ide data summary for the Denver Metropolitan Area. . ... . ..... .. .. .. . 88 CDPH F/A PC D

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### Table 28. 1998 Carbon monoxide data summary for the Denver Metropolitan Area.................. 88 Table 29. 1999 Carbon monoxide data summary for the Denver Metropolitan Area .................. 89 Table 30. Carbon monoxide data during the episode on November 30, 1999 .............................. 90 Table 31. Denver metropolitan area carbon monoxide precision and accuracy probability limits (%difference): Welby, Highland .......................................................................................... 99 Table 32. Denver metropolitan area carbon monoxide precision and accuracy probability limits (%difference): Longmont, Boulder2

- YMCA.................................................................. 100 Table 33 . Denver metropolitan area carbon monoxide precision and accuracy probability limits (% difference): Boulder Marine St., Denver CAMP.......................................................... 101 Table 34. Denver metropolitan area carbon monoxide precision and accuracy probability limits (%difference): Denver NJH, Denver Carriage.............................. .. ................................... 102 Table 35. Denver metropolitan area carbon monoxide precision and accuracy probability limits (%difference): Denver Speer & 

### Auraria, Arvada....... .. ...... ...... ......................................... 103 Table 36. Temporal allocation factors used to distribute AM-Peak, PM-Peak, and Off-Peak onroad mobile emissions for 2006 and 2013 .......................................................................... 557 

# List of Figures Figure 1. Denver metropolitan area carbon monoxide (CO) Urban Airshed Model (UAM) domain and the Nonattainment Area (NAA) boundary. Once the NAA is redesignated for CO , the NAA is known as the Attainment/Maintenace Area. The State is not changing the boundaries, only the area's desgination .................................................................................. 3 Figure 2. Shaded relief map showing the topography in the Denver area...................................... 5 Figure 3 . Air quality modeling process. The meteorological files and preprocessor files from the CO SIP are the basis ofthe UAM maintenance plan modeling ........................................... . 29 Figure 4. Meteorological observation sites used in developing and evaluating the diagnostic wind model for the "high" episode used in the maintenance plan ................................................. 34 Figure 5. Observed hourly concentration values on November 30, 1999 .. . ........ .. ....................... 43 Figure 6. Wind/Carbon Monoxide Roses at the Arvada Site. These show the frequency of occurrence of CO concentrations greater than 3 ppm or 8 ppm , as a function ofwind speed and direction. High CO is largely constrained to the NW quadrant, with wind speeds of4 mph or less ............................................................................................................................ 59 Figure 7. Wind direction and UAM performance are displayed as a function of time for the "high" episode. Model performance is based on the difference between hourly monitored and modeled CO concentrations; a negative value means the model is under-predicting .... 60 Figure 8. One-hour (1-hr) time series plots showing observations (boxes) and model estimates (lines) at CAMP (CMP) and Welby (WBY) .. . ............ . .. .. .............. . .......... .. .......................... 66 Figure 9 . One-hour (1-hr) time series plots showing observations (boxes) and model estimates (Jines) at Carriage (CRG) and NJH............................................................................... . ...... . 67 Figure 10. Eight-hour (8-hr) time series plots showing observations (boxes) and model estimates (lines) at CAMP (CMP) and Welby (WBY) ... .... .... . .......... . ..... . . ... .. .. .......... .. ........................ 68 Figure 11. Eight-hour (8-hr) time series plots showing observations (boxes) and model estimates (Jines) at Carriage (CRG) and NJH................................................................................. .. .... 69 Figure 12. UAM 8-hour CO concentration isopleths for the hour during which the maximum UAM predicted 8-hour concentration occurred during the "high" episode (December 5, 1988) . .... .... ..... . ......................... . ........... .. ............... .. ........................................... .. ................. 70

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### Figure 13. UAM 1-hour CO concentration isopleths for the hour during which the maximum UAM predicted 1-hour concentration occurred during the "high" episode (December 5 , 1988). ··· · · · ············· · · ·· ···· ·· ··········· · ····· · ··· · ············· · · ·· ···· ·· ········ · ········ · ·· · ····················· · ······· · ···· · ·· 71 Figure 14. Urban Airshed Model Results for 2006 (simulation "H") ..... .. . . .. .. .. . . ....... .. .. . . .. ....... .. .. 79 Figure 15. Urban Airshed Model Results for 2012 (simulation "L") .. . .. .. . . .. .. .. . .. ... . .. .. .. . . .. ..... .. .. .. 81 Figure 16. Urban Airshed Model Results for 2013 (simulation "0 11 ) ... .. . .. . .. .. .. ...... . .. .. .. .... ..... .. .. .. 

### 83 Figure 17. Active carbon monox ide monitoring sites in the Denver metropolitan area from 1997- 1999 .. . ... . ...... .. ................ . ................. ... . . .. .. .... .. ..... .. .... .. .... ... .......... .. . .. ........ .. .. .. ... .... ..... . .. .. ... . 86 Figure 18. Historic trends in ambient CO concentrations at CAMP and Speer and Auraria in downtown Denver. ...... . ........................... . ........... .. ..... .. .... .. ........... . . .. .... ... ... .. ....... . . . .. . . .. .... . ... 91 Figure 19. Historic trends in ambient CO concentration at Carriage and NJH in Denver.... . . . .... 92 Figure 20. Historic trends in the ambient CO concentration at Welby and Arvada... .. .. .. .......... . . 93 Figure 21. Historic trends in the ambient CO concentration at Highland and Longmont.. ....... . .. 94 Figure 22. Historic trends in the ambient CO concentration in Boulder at 2320 Marine Street and 2150 28 1 h 

### Street ......................................... . ........... . ...... .. ................. . ............ . .................... . .. 95

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## 2.4. On-Road Mobile Sources Estimates for carbon monoxide (CO) emissions from on-road mobile sources are based on the Environmental Protection Agency (EPA) Mobile Source Emissions Model

- MOBILE5b . 

### 2.4.1. Control Strategy Recommendations Regional Air Quality Commission Mobile Source Carbon Monoxide Control Strategy Recommendation for 2006 and 2013 : • l/M 240 program with newest 4 model-year exemption • 1.5% oxygenated fuel program for 2006 ; 1.7 % oxygenated fuel program for 2013 • 80% Remote Sensing Device (RSD) program 

### 2.4.2. Vehicle Miles Traveled (VMT) The DRCOG 1999-2004 Transportation Improvement Conformity networks were utilized as the basis for the vehicle miles traveled (VMT) estimates. DRCOG has revised population and household growth estimates since this TIP Conformity analysis was complete in August 1998. Incorporating the revised growth rates results in 2006 and 2013 VMT estimated as follows: • 2006 magnitude and distribution ofVMT in the Denver-Boulder NAA represented by 2011 DB Network 2020 AC • 2013 magnitude and distribution ofVMT in the Denver-Boulder NAA represented by 2020 AC Network multiplied by a factor on 1.037 The VMT totals are summarized in the following two tables. 

### Table 10 . Daily VMT totals in the Denver-Boulder carbon monoxide Denver-Boulder Carbon Monoxide Nonattainment Area. Year AM Peak PM Peak Off-Peak Total 2006 9,441,436 21 ,234,530 31 ,012 ,298 61 , 688 ,264 2013 10, 740 ,302 24 ,222 , 119 36,304 ,514 71 ,266 ,935

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### Table 11. VMT totals in the Denver-Boulder carbon monoxide Urban Airshed Modeling domain. Year 2006 2013 AM Peak PM Peak Off-Peak Total 10,179,724 22,873 ,759 33 , 706,082 66 ,759,564 11,582 ,081 26 , 104,812 39 ,499 ,790 77, 186,683 The tabular summaries of vehicle miles traveled by area type and functional classification and the ten peak periods are included in Appendix A. 

### 2.4.3. Mobile5b Emission Factor Modeling Elements ofMobile5b Emission Factor Modeling: 

## • UM 240 program with newest four model years exempt • 1.5% oxygenated fuel program in 2006; 1.7 % oxygenated fuel program in 2013 • 80% RSD program • National Low Emitting Vehicle(NLEV) program commencing in 2001 • Mechanics training credit • The most stringent cut-points available in Mobile5b for an 

### VM 240 program 2006 

### VM 240 program on light duty gasoline powered vehicles is characterized as follows: • Start year (January 1 ): 1982 • Pre-1981 MYR stringency rate: 20% • First model year covered: 1982 • Last model year covered: 2002 • Waiver rate (pre-1981): 0% • Waiver rate (1981 and newer): 0% • Compliance Rate: 98% • Inspection type: Test Only • Inspection frequency: Biennial • Vehicle types covered: LDGV LDGTl LDGT2 • 1981 & 

### later MYR test type: IM240 test • Cutpoints: HC: 0.600 CO: 10.000 NOx: 1.500 2006 

### VM 240 program on heavy duty gasoline powered vehicles is characterized as follows: • Start year (January 1): 1982 • Pre-1981 MYR stringency rate: 20% • First model year covered: 1982 • Last model year covered: 2002 • Waiver rate (pre-1981): 0% • Waiver rate (1981 and newer): 0.% • Compliance Rate: 98.%

CDPHF/APCD/Technical Services Program January 4, 2000 16T echnic al Support D ocume nt Carbon Monoxide Redesign ation R eq u est and Maintenance P lan fo r t he Denver Metr opolit an Ar ea 

### • Inspection type Test Only • Inspection frequency: Biennial • Vehicle types covered: HDGV • 1981 & 

### later MYR test type: 2500 rpm 

### I Idle • Cutpoints: HC: 220.000 CO: 1.200 NOx: 999.000 Anti-tampering program in 2006 for all gasoline-powered vehicles is characterized as follows : • Check: ATP • Start Model Year: 1982 • Model Years Covered: 1975-2002 • Vehicle Classes Covered: LDGV LDGTl LDGT2 HDGV • Inspection Type: Test Only • Frequency : Biennial • Compliance Rate: 98.0% • Air pump system disablement: Yes • Catalyst removals : Yes • Fuel inlet restrictor disablement: No • Tailpipe lead deposit test: No • EGR disablement: No • Evaporative system disablement: No • PCV system disablement: No • Missing gas caps: Yes 2013 I/M 

### Programs and Anti-tampering programs are characterized similarly. 

### 2.4.4. NLEV Credit Estimate The emission reduction affects ofthe National Low Emission Vehicle program on light-duty gas vehicles (LDGV) and light-duty truck 1 vehicles (LDGTl) was estimated for purposes of this analysis though two Mobile5b emission inventory runs. Mobile5b runs are made for high altitude as described above . In order to estimate the NLEV benefit on LDGV and LDGTl , a similar run was made for low altitude with the flags set to include the NLEV program starting in 2001. The emission factors for LDGV and LDGTl vehicles were taken from the low altitude mobile5b runs to replace the same emission factors from the high altitude runs. The composite (vehicle mix weighted) emission factor was then re -calculated. The FORTRAN algorithm used to accomplish these calculations is included in Appendix B. 

### 2.4.5. RSD Program RSD Modeling Inputs: • RSD Fleet Coverage Option 2 (Commitment to vehicle coverage) • Program type= 5 (Clean screening remote-sensing program) • RSD cutpoint .5% CO, 200ppm HC • RSD clean screening with l/M 240 final cutpoint effectiveness

CDPH £1A PCD ! T

echnica/ Se rvices Program January 4, 2000 1 7Technical Support Document Carbon Monoxide Redesignation Request and Ma intenance Plan for the Denver Metropolitan Area 

### • 2006 Vehicle Population of 2, 459 , 748 (Based on 2 million vehicles in 1999 w ith 3 % annual increase) • Fleet subject to clean screen 

## = I 00 % • 80 % Clean Screen (80 % of vehicle population per vehicl e age) • Colorado ' s registration distribution 

### Table 12. Input file in the EPA RSD model to generate the 80% credit file. 000 Clean screen, vehicles projected 2006, 80% rsd 001 2 Commitment to vehicle coverage 002 5 Clean screening RSD 005 Imdata.d 007 Techl2.d 015 Im.d 017 Tech.ct 034 2 ELIGIBLE CLEAN SCREEN PRE 75 035 2 ELIGIBLE CLEAN SCREEN 75-80 036 2 ELIGIBLE CLEAN SCREEN 81-85 037 2 ELIGIBLE CLEAN SCREEN 86-89 038 2 ELIGIBLE CLEAN SCREEN 90 + 039 4 RSD CUTPOINTS AND LEP VALUES (l=.5/200) 044 2 RSD FINAL CUTPOINT 000 NUMBER OF VEHICLES ELIGIBLE FOR CLEAN SCREEN 000 80% RSD 000 

### ----------- ---------- 201 120734 96587 TOTAL VEHICLES, VEHICLES ELIGIBLE 0-1 202 140985 112788 TOTAL VEHICLES, VEHICLES ELIGIBLE 1-2 203 134224 107379 TOTAL VEHICLES, VEHICLES ELIGIBLE 2-3 204 146707 117365 TOTAL VEHICLES, VEHICLES ELIGIBLE 3-4 205 155424 124339 TOTAL VEHICLES, VEHICLES ELIGIBLE 4-5 206 186547 149238 TOTAL VEHICLES, VEHICLES ELIGIBLE 5-6 207 180287 144230 TOTAL VEHICLES, VEHICLES ELIGIBLE 6-7 208 153722 122978 TOTAL VEHICLES, VEHICLES ELIGIBLE 7-8 209 146709 117367 TOTAL VEHICLES, VEHICLES ELIGIBLE 8-9 210 100218 80174 TOTAL VEHICLES, VEHICLES ELIGIBLE 9-10 211 131124 104899 TOTAL VEHICLES, VEHICLES ELIGIBLE 10-11 212 125860 100688 TOTAL VEHICLES, VEHICLES ELIGIBLE 11-12 213 108005 86404 TOTAL VEHICLES, VEHICLES ELIGIBLE 12,13 214 78572 62857 TOTAL VEHICLES, VEHICLES ELIGIBLE 13-14 215 67328 53863 TOTAL VEHICLES, VEHICLES ELIGIBLE 14-15 216 60739 48591 TOTAL VEHICLES, VEHICLES ELIGIBLE 15-16 217 58171 46536 TOTAL VEHICLES, VEHICLES ELIGIBLE 16-17 218 55307 44246 TOTAL VEHICLES, VEHICLES ELIGIBLE 17-18 219 52444 41955 TOTAL VEHICLES, VEHICLES ELIGIBLE 18-19 220 30823 24658 TOTAL VEHICLES, VEHICLES ELIGIBLE 19-20 221 24506 19605 TOTAL VEHICLES, VEHICLES ELIGIBLE 20-21 222 18254 14603 TOTAL VEHICLES, VEHICLES ELIGIBLE 21-22 223 11937 9550 TOTAL VEHICLES, VEHICLES ELIGIBLE 22-23 224 4885 3908 TOTAL VEHICLES, VEHICLES ELIGIBLE 23-24 225 1432 1145 TOTAL VEHICLES, VEHIC LES ELIGIBLE 24-25

C

DPHF/A PC D

!Technical Services Program Janumy 4, 2000 18Technical Support Document Carbon Monoxide R edesignation Request and Maintenance Planfor the Denver Metropolitan Area 

### Table 13. Data used in model year calculations of eligible vehicles. VEHICLE COUNT FOR 2006 BASED ON 3% INCREASE PER YEAR 1999 = 2,000,000 1999 2000 2001 2010 2011 2002 2003 2004 2005 2006 2007 2008 2009 2000000 2060000 2121800 2185454 2251018 2318548 2388105 2459748 2533540 2609546 2687833 2768468 2851522 VMT WEIGHTED AVERAGE VEHICLE MIX FOR 2006 LDGV LDGTl LDGT2 HDGV

VEHICLE AGE 0.582 0.221 0.104 0.026 1431573 543604 255814 63953 TOTALS 2294945

LDGV* LDGV TOTALS LDGTl* LDGTl 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 0.049 0.065 0.067 0.074

0.08 0.083 0.082 0 . 068 0.065 0.043 0.058 0.052 0 . 045 0 . 034 0.028 0 . 024 0.021 0.019 0.017 0.009 0.007 0 . 005 0.003 0.001 0.001

1 70147 0.058 93052 0.055 95915 0 . 044 105936 0.047 114526 0.047 118821 0.078 117389 0.071 97347 0.065 93052 0.062 61558 0 . 045 83031 0.056 74442 0 .06 64421 0.051 48673 0 . 035 40084 0.032 34358 0 . 031 30063 0.033 27200 0.033 24337 0.033 12884 0.021 10021 0.017 7158 0. 013 4295 0.009 1432 0.004 1432 0 1431573 1 * REGISTRATION DISTRIBUTION

CDPHE'APCD ! Technica/ Services Program TOTALS 31529 29898 23919 25549 25549 42401 38596 35334 33703 24462 30442 32616 27724 19026 17395 16852 17939 17939 17939 11416

9241 7067 4892 2174

0 543604 LDGT2* LDGT2 0.058 0 . 055 0.044 0.047 0 . 047 0 . 078 0. 071 0.065 0.062 0.045 0.056

0.06 0.051 0 . 035 0.032 0 . 031 0.033 0.033 0 . 033 0. 021 0.017 0.013 0 . 009 0.004

0 1 TOTALS 14837 14070 11256 12023 12023 19953 18163 16628 15860 11512 14326 15349 13047

8953 8186 7930 8442 8442 8442 5372 4349 3326 2302 1023

0 255814 HDGV* 0.066 0.062 0.049

0.05 0.052 0.084 0.096 0.069 0.064 0.042 0 . 052 0.054 0.044

0.03 0.026 0 . 025 0.027 0.027 0 . 027 0.018 0.014 0. 011 0.007 0.004

0 1

January 4, 2000 HDGV TOTALS

4221 3965 3134 3198 3326 5372 6140 4413 4093 2686 3326 3453 2814 1919 1663 1599 1727 1727 1727 1151 895 703 448 256

0 63953 GRAND TOTALS 120734 140985 134224 146707 155424 186547 180287 153722 146709 100218 131124 125860 108005 78572 67328 60739 58171 55307 52444 30823 24506 18254 11937 4885 1 432 2294945

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